REVIEW article

Front. Aging Neurosci., 25 August 2025

Sec. Alzheimer's Disease and Related Dementias

Volume 17 - 2025 | https://doi.org/10.3389/fnagi.2025.1637671

The manipulator behind “Scissors”: γ -secretase and its modulators in Alzheimer’s disease

  • 1. Yan’an Medical College of Yan’an University, Yan’an, Shaanxi, China

  • 2. Yan’an Key Laboratory of Northern Shaanxi Tumor Prevention and Treatment, Yan’an Medical College, Yan’an University, Yan’an, Shaanxi, China

Abstract

The intramembrane aspartic protease, γ-secretase, is a heterotetrameric protein complex composed of four integral membrane proteins: presenilin (PSEN), nicastrin (NCT), Anterior pharynx defective-1 (APH-1), and presenilin enhancer 2 (PEN-2). These components are sequentially assembled into a functional complex. γ-secretase is ubiquitously expressed in all cells and tissues and exhibits enzymatic activity akin to “molecular scissors” by cleaving various type I transmembrane proteins. The primary substrates of this complex include amyloid precursor protein (APP) and Notch. The role of APP in the pathogenesis of Alzheimer’s disease (AD) has been extensively investigated. Although γ-secretase inhibitors (GSIs) have been evaluated for their therapeutic potential in AD, their clinical application is limited due to significant toxic side effects. Recently, γ-secretase modulators (GSMs) have emerged as promising alternatives, offering new opportunities for the treatment of AD, especially the inherent γ-secretase modulatory proteins (GSMPs) within cells. Research on GSMPs has ushered in a new era for mitigating the side effects of AD drugs. In this review, we systematically summarize recent advancements in the study of γ-secretase in relation to AD and provide an overview of GSMs and GSMPs, thereby offering potential insights for the development of therapeutic strategies for AD.

1 Introduction

The γ-secretase complex is an intramembrane-cleaving protease (I-CliP) that catalyzes the intramembrane domain (TMD) of its protein substrates and performs a wide variety of essential biological roles (Wolfe, 2019). The γ-secretase has been identified as a heterotetrameric complex consisting of four membrane protein subunits: APH-1, NCT, PSEN, and PEN-2 (Oikawa and Walter, 2019; Figure 1A). It takes a stepwise manner to assemble the four subunits into one complex, the correct assembly of the γ-secretase is tightly regulated, and then the mature γ-secretase complex is transported to the plasma membrane and endosomes to perform its functions (Dries and Yu, 2008; Smolarkiewicz et al., 2013; Figure 1B). Alzheimer disease (AD) is a common cause of cognitive impairment in middle-aged and elderly people. It is a hereditary and sporadic neurodegenerative disorder (Knopman et al., 2021). Excessive phosphorylation of tau protein (; ), and deposition of beta-amyloid protein (Aβ) are currently the mainstream theories recognized as causing AD (Wolfe, 2024). γ-secretase has various substrates, in AD, γ-secretase produces Aβ by cleaving amyloid precursor protein (APP). The abnormal accumulation and aggregation of these peptides are considered crucial factors in the pathological changes of AD (Kim et al., 2024). Despite the key role γ-secretase plays in AD pathogenesis (Hakem et al., 2024), direct inhibition strategies have not achieved satisfactory outcomes in clinical trials, largely because inhibiting multiple γ-secretase substrates may disrupt normal physiological functions (Dries and Yu, 2021; Caldwell et al., 2022). As a result, researchers are investigating alternative approaches to regulate γ-secretase activity, such as the creation of GSMs, which represent a class of small molecules capable of influencing the activity of γ-secretase (Wolfe, 2024; Hakem et al., 2024). Unlike GSIs, which directly suppress the enzyme’s activity, GSMs modify the cleavage patterns of substrates via allosteric regulation. This process leads to a reduction in the generation of harmful amyloid peptides (Rynearson et al., 2021; Petit et al., 2022). Furthermore, the design of GSMs aims to minimize side effects associated with GSIs observed during clinical trials, such as interference with the Notch signaling pathway (Hur, 2022). In recent years, the growing comprehension of γ-secretase’s structure and function has enhanced our knowledge of GSM mechanisms. Cryo-electron microscopy has played a pivotal role in mapping the structural configuration of γ-secretase when it interacts with GSMs, revealing critical details about how GSMs influence the γ-secretase complex (Dries and Yu, 2021; Yang et al., 2021). Studies on GSMs can help to improve our targeted therapy for AD.

FIGURE 1

The activity of γ-secretase is modulated by a variety of factors, including the properties of its substrates and the intracellular microenvironment. In addition to APP, many γ-secretase substrates are associated with AD, such as Notch, CD43, CD44, CD91, CD269, CSF-1R, etc., The study of these substrates related to AD may give us new ideas about whether they regulate the activity of γ-secretase to act together in AD. There is evidence that the enzymatic activity of γ-secretase can also be influenced by interferon-induced transmembrane protein 3 (IFITM3), which is upregulated in tissue samples from certain late-onset Alzheimer’s disease patients and exhibits a positive correlation with γ-secretase activity (Hur et al., 2020). Several studies have demonstrated that inhibiting γ-secretase-activating protein (GSAP) effectively reduces Aβ production while leaving other critical γ-secretase substrates unaffected (Kim et al., 2024). Apolipoprotein E (ApoE), the most prominent genetic risk factor for sporadic Alzheimer’s disease (sAD), interacts with γ-secretase and selectively inhibits its activity in a substrate-dependent manner (Hou et al., 2023). These intracellular proteins, which regulate γ-secretase, are referred to as γ-secretase modulatory proteins (GSMPs). If GSMPs can be effectively modulated to achieve therapeutic effects for AD, this approach may potentially further mitigate the side effects associated with chemical drugs. In summary, γ-secretase and its substrates are intricately associated with the onset and progression of AD. A deeper investigation into the underlying mechanisms is crucial for advancing AD treatment. Notably, targeted therapies involving GSMs and GSMPs hold promise in providing new hope for AD patients.

2 Subunits of γ-secretase and their assembly

2.1 Subunits of γ-secretase

2.1.1 PSEN

Early in the 1990’s, two human early-onset familial Alzheimer’s disease (EOFAD) -related loci were discovered on chromosomes 14 (Rogaev et al., 1995) and 1 (Schellenberg et al., 1992). These loci were subsequently identified as two homologous genes: Presenilin1 (psen1) and Presenilin2 (psen2) (Levy-Lahad et al., 1995; Sherrington et al., 1995). PSEN are the catalytic components with aspartyl protease activity, and more than 150 AD causing mutations have been reported in both genes, with the majority occurring in PSEN1 (Zhang et al., 2014). The full-length PSEN consists of nine transmembrane helices (TM1-9) and two catalytic aspartate residues in TM6 (Asp257) and TM7 (Asp385) (Spasic et al., 2006). During γ-secretase complex maturation, the presenilin holoprotein becomes inactive and is rapidly degraded by proteolytic activity. PSEN undergoes autoproteolysis into stable N-terminal fragments (NTF, TM1-6) and C-terminal fragments (CTF, TM7-9) (Fraser et al., 1998; Kim et al., 1997; Thinakaran et al., 1996; Figure 1A). The endoproteolytic fragments of PSEN proteins are predominantly localized in the endoplasmic reticulum (ER) and Golgi apparatus (), but also found in the plasma membrane (Marambaud et al., 2002), endosomes (Vetrivel et al., 2004), phagosomes (Jutras et al., 2005), lysosomes (Sannerud et al., 2016), mitochondria (; ), and nuclear envelope (Kimura et al., 2001). where they are interacted with NCT, APH-1, and PEN-2 to form a 250kDa complex (Yu et al., 1998).

2.1.2 NCT

A novel protein (Nicastrin, NCT) was found in 2000 by immunoprecipitation of PSEN1 combined with mass spectrometry (Yu et al., 2000). Nicastrin was named after the Italian village of Nicastro, where the PSEN-associated forms of Familial Alzheimer’s disease were discovered (Feldman et al., 1963; Foncin et al., 1985). Human NCT gene maps to chromosomee 1, it has been identified as risk genes for Alzheimer’s disease susceptibility locus in two genome surveys (Zubenko et al., 1998; Owen et al., 2000). NCT is a type I transmembrane glycoprotein with 709 amino acids, a putative amino-terminal signal peptide, an N-terminal hydrophilic domain, N-myristoylation and phosphorylation motifs, a transmembrane domain, and a 20-residue hydrophilic carboxy terminus (Yu et al., 2000; Figure 1A). The conserved functions of NCT for Notch signaling have been revealed from studies in Caenorhabditis. Elegans (Goutte et al., 2000), Drosophila melanogaster (Chung and Struhl, 2002; Hu et al., 2002), and mice (). NCT is the first identified PSEN cofactor, and it plays a critical role in PSEN-mediated processing of APP and notch/glp-1 signaling (Yu et al., 2000). The ectodomain of NCT is proposed to recruit substrates into the γ-secretase complex (Shah et al., 2005; Dries et al., 2009).

2.1.3 APH-1

In the genetic screening of Notch, psen, and NCT in C. elegans, two multipass transmembrane proteins, Anterior pharynx defective-1 (APH-1) and Presenilin enhancer-2 (PEN-2), interact strongly with PSEN (SEL-12 in C. elegans) and NCT (APH-2 in C. elegans); APH-1 deficiency caused a comparable phenotype to psen and NCT (Francis et al., 2002; Goutte et al., 2002). In mammals, APH-1 is a seven transmembrane protein of approximately 25 kDa (Figure 1A). The GxxxG motif in the fourth TMD of APH-1 is critical for the formation and activation of the γ-secretase complex. APH-1 physically interacts with immature NCT (imNCT) in ER to form a stable subcomplex (LaVoie et al., 2003; Lee et al., 2004), then binds to the C-terminus of PSEN holoprotein (Morais et al., 2003; Steiner et al., 2008). The ternary complex of imNCT/APH-1/holo-PSEN is then transported to the trans-Golgi, where NCT can fully develop and become extensively N-glycosylated. Human APH-1 is encoded by aph1a and aph1b, of which aph1a appears to be the more studied.

2.1.4 PEN-2

The PEN-2 was identified side-by-side with APH-1 in a C. elegans screening (Francis et al., 2002; Goutte et al., 2002). Human PEN-2 is encoded by a single gene on chromosome 19 (Panmontha et al., 2015). It is the smallest component of γ-secretase with 101 residues, two hydrophobic domains that function as transmembrane spanning domains, and a “U-shaped” structure with the N- and C- termini toward the lumen, according to earlier reports (Crystal et al., 2003; ; Figure 1A). Recent structure research of PEN-2, however, has revealed that there are three membrane-embedded domains, with the C-terminus being luminal and the N-terminus being exposed to the cytoplasm, indicating that the first two domains traverse only half of the lipid bilayer (Zhang et al., 2015). PEN-2 is the last protein to be incorporated into the γ-secretase complex and regulates PSEN auto-hydrolysis and NCT maturation (Francis et al., 2002; Watanabe et al., 2006), and it serves as an ER retention receptor for the immature γ-secretase complex (Fassler et al., 2005). The extracellular region of PEN-2 can interact with the ectodomain of NCT (Sun et al., 2015). The N-terminal extension of PEN-2 can modify the hydrophilic environment of the PSEN catalytic pore (Isoo et al., 2007). Thus, PEN-2 may modulate γ-secretase activity.

2.2 Assembly and activation of γ-secretase complex

The correct assembly of the γ-secretase is tightly regulated. It is now widely acknowledged that it takes a stepwise manner to assemble the four subunits into one complex. First, the Nicastrin is synthesized and modified with N-glycosylated in the ER to form imNCT, which then binds to APH-1 to form the heterodimer imNCT/APH-1 subcomplex I (LaVoie et al., 2003). In order to build subcomplex II, the Proximal C-terminus of the PSEN holoprotein connects to the intermediate heterodimer via the TM domain of NCT (Kaether et al., 2005). Then, PEN-2 and TM4 of PSEN are combined to create subcomplex III (Kornilova et al., 2006; Watanabe et al., 2006). However, it is unclear whether this complex is generated by successive binding of PSEN1 and PEN-2 or by a prefabricated PSEN1/PEN-2 subcomplex (Fraering et al., 2004). Subcomplex III is immediately followed by PSEN autoproteolysis at TMD6 and TMD7 to produce PSEN-NTF and PSEN-CTF fragments, which comprise the active form of PSEN inside subcomplex IV (Fukumori et al., 2010). If PEN-2 is not present, the subcomplex is degraded via proteasomes (Prokop et al., 2004). In a next step, approximately 5% of subcomplex IV traffics to the Golgi, where NCT is further N-glycosylated to form mature Nicastrin (mNCT), and this is the subcomplex V (Moniruzzaman et al., 2018), represents the formation of active γ-secretase in the cell. Finally, the mature active γ-secretase complex is then transported to the plasma membrane and endosomes (Dries and Yu, 2008; Smolarkiewicz et al., 2013; Figure 1B). The four-component intramembrane proteinase gamma-secretase is intricately linked to the development of various diseases. Single-particle electron cryo-microscopy revealed the principle of the assembly of four subunits, with PSEN1 in the central position, its amino terminal fragment (NTF) wrapped by PEN-2, and its carboxyl terminal fragment (CTF) interacting with APH-1. NCT’s unique TM binds to APH-1, and its extracellular domain binds to PEN-2. TM6 and TM7 in PSEN1 are located on the convex side of the TM horseshoe shape and contain catalytic aspartate residues. This structure provides an important framework for understanding the function of γ-secretase (Sun et al., 2015). The complex of γ-secretase with the Notch fragment indicates that three transmembrane domains of PSEN1 surround the transmembrane helix of Notch, and PSEN1 undergoes a significant conformational rearrangement when binding to its substrate. These features reveal structural changes in γ-secretas during substrate recruitment (Yang et al., 2019). Post-translational modifications can further regulate the matured γ-secretase. The phosphorylation of PSEN1, PSEN2 and NCT regulate functions of γ-secretase complex, including the proteolytic processing, γ-secretase activity (Fluhrer et al., 2004; Walter et al., 1999; Kuo et al., 2008), stability (Lau et al., 2002) and subcellular localization (Sannerud et al., 2016). The assembly and activation of the four subunits play an important role in the function of γ-secretase.

γ-secretase complex is ubiquitous in all tissues, the presence of all γ-secretase subunits does not guarantee active complex formation, many evidences suggest that two pools of γ-secretase exist: the long half-life of assembling γ-secretase complex and the short half-life of monomeric subunits, and only a small fraction of γ-secretase is catalytically active (; Lai et al., 2003). A broad range of γ-secretase substrates has been identified, suggesting that additional events and cofactors composition are required to enhance the activity of γ-secretase and substrate specificity (Placanica et al., 2010). Although γ-secretase can cleave a variety of protein substrates, when cells are in different environments and receive different signals, γ-secretase may selectively hydrolyze one or a class of substrates to ensure the normal execution of cell functions. γ-secretase subunits are localized in nearly all endomembrane system compartments, including the endoplasmic reticulum (Kaether et al., 2004), lysosomal membrane (Houser et al., 2023), pre- and post-Golgi compartments (), phagosome (Jutras et al., 2005), plasma membrane and endosome (Vetrivel et al., 2004). This suggests that in different cellular domains γ-secretase binds to different substrates and plays different roles. Thus, the activity of γ-secretase may be regulated by a variety of mechanisms. For instance, APP is processed by intracellular γ-secretase, while Notch, which acts on the plasma membrane, is processed on the cell surface (Tarassishin et al., 2004). Furthermore, lipid composition also impacts substrate processing, the cholesterol-rich membranes are the major site of Aβ production (Wahrle et al., 2002; Marquer et al., 2014), and γ-secretase partitioning into lipid bilayers remodels membrane components that create a suitable microenvironment for substrate recognition and activity (). Only correct subunit assembly can enable γ-secretase to recognize specific substrates under specific environment and conditions, thus being actived and performing the correct cell biological functions.

3 γ-secretase in Alzheimer’s disease

Over a 100 distinct type I integral membrane proteins have been identified as γ-secretase substrates to date, and more are being continuously discovered (Hemming et al., 2008; Haapasalo and Kovacs, 2011). γ-secretase was originally characterized based on its proteolytic function in cleaving the APP, a process that generates Aβ—a key pathological component in the formation of senile plaques associated with AD. Consequently, γ-secretase is widely regarded as a central player in the pathogenesis of AD. Beyond APP, an expanding repertoire of γ-secretase substrates has been implicated in the molecular mechanisms underlying AD development. In the following sections, we will systematically examine those proteins that demonstrate significant associations with the onset and progression of AD, aiming to elucidate the multifaceted roles of γ-secretase in disease pathology and to lay a foundation for the development of targeted therapeutic interventions.

3.1 Amyloid precursor protein (APP)

Alzheimer’s disease was first officially described by Alois Alzheimer in 1906, which is the most common form of dementia (Small and Cappai, 2006). The excessively aggregates amyloid plaques in the brain majorly contribute to dysfunction and degeneration of neurons that result in AD (Zhang et al., 2012). Although the etiology of Alzheimer’s disease is still the subject of considerable debate, the “amyloid-cascade hypothesis” has remained the prevailing theory over the years (Small and Cappai, 2006; Soria Lopez et al., 2019). This hypothesis suggests that amyloid plaques in the brains of AD patients consisted of fibrils formed by Aβ. The cleavage by γ-secretase requires shedding of the substrate’s extracellular domains by the other secretases. In the Non-Amyloidogenic pathway, APP is cleaved by α-secretase to generate sAPPα and the membrane-associated 83 amino acid C-terminal fragment APP-CTF (C83), γ-secretase further cleaves C83 to produce p3 and AICD (Selkoe, 2001; Figure 2A). Alternatively, in the amyloidogenic pathway, APP is first processed by β-secretase and produces the secreted sAPP-β and APP–C-terminal 99-residue fragment (C99), subsequent γ-Secretase mediated cleavage of C99 at the γ-, ζ-, and ε-sites close to the cytosolic end of TMD to generate APP intracellular domain (AICD) and the extracellular secretion of Aβ peptides (Moser et al., 2024). The cleavage of C99 by γ-secretase results in a variety of peptides (from large Aβ49 peptides to smaller ones with 37 residues), Aβ peptides are cleaved mainly by tripeptide trimming or tetrapeptide trimming via the Aβ40 product line (Aβ49→46→43→40→37) or the Aβ42 product line (Aβ48→45→42→38) (Hur, 2022; Takami et al., 2009; Wang et al., 1996; Figure 2B).

FIGURE 2

Approximately 25 mutations in APP are associated with the occurrence of AD, many of which are located in the area of TMD (Devkota et al., 2021). Although there have been numerous debates on whether immune activity is advantageous or detrimental to the progression of AD pathology, it has long been that immune activity is closely related to the pathophysiology of AD (Frost et al., 2019).

3.2 Other GS substrate proteins related to AD

In addition to APP, γ-Secretase has more than 140 substrates, all of which are type 1 transmembrane proteins. Among them, many substrates have been reported to be related to the APP. For instance, the low-density lipoprotein receptor-related protein (LRP) directly interacts with the PS1 subunit of γ-secretase and competes with APP for access to the enzyme’s cleavage site. Overexpression of the C-terminal fragment of LRP decreases the production of Aβ peptides derived from APP and suppresses the signaling activity of AICD (Lleó et al., 2005). These findings indicate that LRP functions as a competitive substrate, modulating the cleavage of APP by γ-secretase through occupancy of the enzyme’s active site. Based on the important role of APP in AD, the research on these substrates may be more conducive to our study of the molecular mechanism of AD pathogenesis. We input the 149 substrate proteins of γ-Secretase (Güner and Lichtenthaler, 2020) into the STRING website (STRING: functional protein association networks) to screen the APP-related proteins centered on this APP (Figure 3). The screened proteins were analyzed and compared with AD in the Human Disease Database Retrieval (MalaCards) and the Disgenet database. These proteins are summarized in Table 1.

FIGURE 3

TABLE 1

Protein nameGDAS (MalaCards)GDAS (disgenet)Functions in AD
Alcadein α (Calsyntenin-1) (Hata et al., 2009)22.120.2Binding to kinesin-1 motors to mediate axonal anterograde transport of certain types of vesicles. APP is transported through these vesicles ()
Alcadein γ (Calsyntenin-3) (Hata et al., 2009)NR0.2Regulate synaptic function (Uchida et al., 2013)
APLP1 (Schauenburg et al., 2018)24.010.35APLP1 plays a role in the formation and maturation of cortical synapses. (Kim et al., 1995)
APLP2 (Eggert et al., 2004)33.560.3Regulate neural development and myelination (Roisman et al., 2019)v
apoER2(LRP8) (Fuentealba et al., 2007)20.680.8Regulate synaptic plasticity and Aβ (amyloid-beta) metabolism (Kim et al., 2014)
APP (Xu et al., 2016)567.731The basis for the formation of amyloid plaques in the brains of patients with Alzheimer’s disease (De Strooper et al., 1998)
CX3CR1 (CCRL1) (Güner and Lichtenthaler, 2020)NRNRCX3CL1 ICD may hold significant translational potential for neuroprotection in Alzheimer’s disease and for disorders associated with insulin resistance (Gayen et al., 2022).
CD147 (Basigin BSG) (Güner and Lichtenthaler, 2020)14.51NRCD147 subunit within the gamma-secretase complex down-modulates the production of Abeta-peptides (Zhou et al., 2005).
CD44 (Lammich et al., 2002)13.04NRCD44 encodes a cell surface glycoprotein that is associated with inflammation, metastasis, and inflammatory-linked neuronal damage (Pinner et al., 2017).
CSF-1R (Wei et al., 2021)131.90.96Microglia are dependent on signaling through the colony stimulating factor-1 receptor (CSF-1R/CD115) for growth and survival (Walker et al., 2017).
Delta1(DLK1) (Ikeuchi and Sisodia, 2003)NRNRRegulate neuroinflammation and the functions of glial cells (Zheng and Wang, 2025).
DR6 (TNFRSF21) (Colombo et al., 2018)NR0.25Regulate neuronal degeneration and neuroinflammation (Zeng et al., 2012)
EphB2 (Xu et al., 2009)NRNRRegulate synaptic plasticity and the inflammatory response (Shi X. D. et al., 2016)
ErbB4 (Ni et al., 2001)NRNRRegulate synaptic plasticity, neuroinflammation, as well as Aβ (amyloid-beta protein) (Chaudhury et al., 2003).
IGF-1R (McElroy et al., 2007)13.810.8The IGF 1/IRS-2 signaling pathway can regulate the activities of alpha-/beta-secretase,and inhibit the production of Aβ (amyloid-beta) (Freude et al., 2009)
IL-1R1 (Elzinga et al., 2009)NR0.45Reducing the interleukin-1β receptor-1 (IL-1R1) negative regulator TOM1 affected microglia activity, increased amyloid-beta levels (Martini et al., 2019).
LDLR (Kim et al., 2018)19.790.85Regulate the cholesterol metabolism in the brain ()
LRP1 (Zurhove et al., 2008)44.340.8LRP1 is involved in efflux of amyloid beta-peptide (1-42) (Sultana et al., 2010)
LRP1b (Liu et al., 2007)NRNRRegulate neurodegeneration ()
LRP6 (Mi and Johnson, 2007)21.90.35Regulate the function and stability of synapses (Buechler and Salinas, 2018)
LRP2 (Zou et al., 2004)NR0.35LRP2 deficiency mice at the mediating BBB leads to neurodegeneration (Dietrich et al., 2014).
N-cadherin (CDH2) (Marambaud et al., 2003)NRNRThe cleaved levels of N-cadherin were increased in homogenates of postmortem brain from AD patients compared with that in non-AD patients. (Choi et al., 2020)
Neuregulin-1 (NLGN1) (Malvankar and Wolfe, 2025)NRNRNeuro protective effect (Sun et al., 2020)
SEZ6L (Pigoni et al., 2016)NRNRSEZ6L is a neuronal substrate of the AD β-secretase, and function in the nervous system (Ong-Pålsson et al., 2022)
SorCS1 (Nyborg et al., 2006)NRNRRegulate synaptic formation and function (Savas et al., 2015)
SorLA (Sorl1) (Nyborg et al., 2006)NR0.65Regulate the processing of amyloid precursor protein (APP), the metabolism of Aβ (amyloid-beta protein), and the intracellular transportation within neurons (Jensen et al., 2023).
Sortilin (Nyborg et al., 2006)14.030.65Participate in the regulation of the clearance of Aβ (amyloid-beta) ()
TkrB (NTRK2) (Tejeda et al., 2016)NRNRTrkB receptor agonist blocks δ-secretase activity exhibiting promising therapeutic efficacy in 3xTg AD mouse model (Liao et al., 2021).
TNFRSF1A (TNFR1) (Chhibber-Goel et al., 2016)NRNRA novel substrate of γ -secretase composed of ps1. The IL-1R1 ICD produced by γ -secretase translocates to the nucleus under the stimulation of IL-1β (Chhibber, 2013).
TREM2 (Wunderlich et al., 2013)117.711TREM2 exerts an anti-inflammatory effect in the brain (Jonsson et al., 2013).
TRKA(NTRK1) (Merilahti et al., 2017)21.30.8It mediates the signal transduction of nerve growth factor (NGF) and regulates neuronal survival, synaptic plasticity, and the metabolism of pathological proteins (Chen et al., 2008).
VLDLR (Hoe and Rebeck, 2005)21.240.8Regulate lipid metabolism (Moulton et al., 2021)

γ-secretase’s substrates associated with Alzheimer’s disease (AD).

The table sequentially lists the names and species of the proteins, the gene scores related to Alzheimer’s disease (AD) from the MalaCards and Disgenet databases, as well as their roles in AD. NR, not retrieved; GDAS, gene-disease association score.

4 γ-secretase modulators (GSMs)

4.1 GSMs

γ-secretase modulators exhibit greater therapeutic potential by modulating enzyme activity to selectively decrease Aβ42 levels while preserving the normal processing of other substrates (Mekala et al., 2020; Wolfe, 2012). Cryo-electron microscopy revealed that GSMs bind to the transmembrane domain of PS1 and change the conformation of γ-secretase, thereby reducing Aβ42 production and enhancing Aβ38 generation (Yang et al., 2021; Mehra and Kepp, 2021; Figure 4). In addition, Petit et al. demonstrated that certain GSMs enhance the efficiency of substrate processing by stabilizing the interaction between γ-secretase and APP, elucidating the mechanism of their selective regulation (Petit et al., 2022). Early GSMs, such as non-steroidal anti-inflammatory drugs (NSAIDs), were ineffective due to insufficient potency and unfavorable pharmacokinetic properties. NSAIDs mainly alleviate Aβ-induced neuroinflammation by inhibiting COX-1, COX-2 and prostaglandins (Imbimbo et al., 2010). Ibuprofen, flurbiprofen, and indomethacin can regulate γ-secretase, lowering Aβ42 levels while increasing Aβ38 (Eriksen et al., 2003). However, clinical trials have not confirmed significant efficacy in patients with mild to moderate AD (Miguel-Álvarez et al., 2015). Although studies on indomethacin have shown some positive trends, the results are not convincing due to the small sample size (de Jong et al., 2008). Research indicates that NSAIDs may be effective in the early stage of the disease but ineffective or even harmful in the later stages (Hampel et al., 2020). Moreover, most NSAIDs have difficulty penetrating the blood-brain barrier (BBB), limiting their efficacy (Sastre and Gentleman, 2010), and the effects are also influenced by individual genetic backgrounds (DiBattista et al., 2016). Recently, novel GSMs, including pyridine derivatives, purine compounds, and quinazolinones, have exhibited greater potency and selectivity. The purinergic GSMs developed by Rivkin’s group substantially reduced brain Aβ42 levels in a mouse model (Rivkin et al., 2010). The incorporation of lipophilic groups has been shown to improve membrane permeability and central exposure (Naumann et al., 2013; Sekioka et al., 2020b). The newer-generation GSM BPN-15606 does not inhibit overall γ-secretase activity. Instead, it binds to the PS1 subunit of γ-secretase, allosterically altering APP cleavage to reduce Aβ42/Aβ40 production and promote the generation of more easily cleared fragments Aβ38/Aβ37 (Wagner et al., 2017). In PSAPP transgenic mice, treatment with BPN-15606 before significant plaque formation effectively reduced amyloid deposition and improved cognitive performance. However, when treatment started six months of age—after plagues were already widespread—the drug reduced Aβ pathology but did not improve existing cognitive impairments (Prikhodko et al., 2020). This suggests that once neuronal damage becomes irreversible, lowering Aβ levels alone may not be sufficient to restore cognitive function. Mobley’s team in Down syndrome mice showed that BPN-15606 significantly reduced Aβ42 and Aβ40 levels; improved nerve growth factor signaling; reduced tau hyperphosphorylation, and corrected behavioral deficits, indicating its potential to delay or prevent AD onset in individuals with Down syndrome (Chen et al., 2024). Preclinical studies also demonstrated favorable pharmacokinetics and safety profiles supporting its advancement into clinical trials (Wagner et al., 2017; Gunnar et al., 2023). Although the new generation of GSMs possesses theoretical safety advantages based on their mechanism of action, practical challenges remain for these modulators. Firstly, the substrate diversity of γ-secretase may result in off-target effects, necessitating the development of more precise modulators. Secondly, the activity of γ-secretase in the brains of AD patients varies with disease progression, potentially influencing drug efficacy (Nobuto et al., 2013). Future research should focus on structure-based drug design, combining cryo-electron microscopy and computational chemistry to optimize binding sites. Developing multi-targeted modulators for Aβ and tau pathologies is also crucial (Gunnar et al., 2023; Joanna and Yue-Ming, 2022; Ji-Yeun, 2022). The existing GSMs are summarized in Table 2.

FIGURE 4

TABLE 2

NameMechanism of drug actionPhaseStatusSide effect
Ibuprofenmodulate γ-secretase to lower the production of Aβ42 and concomitantly increase Aβ38 without affecting the total amount of Aβ (Weggen et al., 2001)IIICompletedWeak efficacy or insufficient targeting (Ling et al., 2015)
IndomethacinSelectively reducing the levels of Aβ42 while simultaneously increasing the production of soluble Aβ38 without affecting Notch signaling.IIICompletedDamage to the gastric mucosa, ulceration, and bleeding (Sava, 2021)
Sulindac sulfideSelective inhibition of Aβ42 production and increase of Aβ38 and Aβ37 fragments ()PreclinicalSuspendedGastrointestinal pain, Dizziness/headache (Brogden et al., 1978)
R-flurbiprofenSelective binding to the active site of γ-secretase modulates its cleavage preference, consequently diminishing the production of Aβ42. (Höttecke, 2010)IIITerminatedLow potency and poor CNS penetration (Green et al., 2009)
CHF-5074CHF-5074 binds to the intracellular domain of APP, altering the cleavage site of γ-secretase and preferentially reducing Aβ42 production (Branca et al., 2014)IICompletedMild diarrhea ()
EVP-0962It decreases the production of Aβ42 peptide and increases the proportion of short-chain Aβ38, thereby decreasing amyloid plaque formation (Bulic et al., 2011)IICompletedIt was discontinued after a phase II clinical trial, and the results are not reported (Hur, 2022)
E2012Targeting the hydrophobic pocket within the transmembrane domain of PS1-NTF (Luo and Li, 2022)ITerminatedAffecting cholesterol metabolism, leading to lenticular opacity (Nakano-Ito et al., 2014)
E2212Reducing Aβ42/40 peptides while increasing soluble Aβ37/Aβ38 (Maia and Sousa, 2019)ICompletedDiarrhea (Yu et al., 2014)
PF-06648671Reductions of Aβ42 and Aβ40, together with increases in Aβ37 in healthy volunteers ()IIITerminatedNo major side effects were reported.
BMS-932481increase in Aβ37 and reduce of Aβ42 CSF levels in healthy volunteers (Boy et al., 2019)IITerminatedLiver injury, alanine aminotransferase (ALT) elevated (Zhuo et al., 2023)
NGP555Binding of the interacting regions of Pen-2, Nct, and TM loops 3-4 to regulate Aβ peptide generation (Ioppolo et al., 2021)ICompletedHeadache, nausea, and dizziness, liver enzyme levels were elevated (Rynearson et al., 2021)
BIIB042Binding to PSEN and induces γ-secretase conformational change, decrease Aβ42, increase Aβ38 and have no effect on Aβ40 levels (Scannevin et al., 2016).IISuspendedNo relevant studies
RO7185876Altering the cleavage site of APP, reduces Aβ40 production and increases Aβ37/Aβ38 (Ratni et al., 2020)PreclinicalUnclearNo relevant studies
RG6289Decrease Aβ42/Aβ40 and elevations in Aβ38 and Aβ37 (De Strooper and Karran, 2024)IIActiveMild headache, gastrointestinal discomfort
BPN-15606Lowering Aβ42 accumulationPreclinicalActiveHigh Dose toxicity in animal (Wagner et al., 2017)
UCSD-776890Potent in vitro and in vivo Aβ42 inhibition;PreclinicalActive.No sign of cardiac toxicity and mutagenicity (Rynearson et al., 2021)
RO7019009Increasing Aβ37/38, reducing Aβ40/42/43, has greater therapeutic potential for patients carrying a single PS1 L166P allele. (Trambauer et al., 2025)PreclinicalActiveNo reports
ACD680Decrease Aβ42/Aβ40 and elevations in Aβ38/Aβ37 (Nordvall et al., 2025)PreclinicalActiveNo reports
UCSD-779690Potent Aβ42 inhibitionPreclinicalUnclearNo sign of cardiac toxicity and mutagenicity (Rynearson et al., 2021)
Cpd133Inhibition of Aβ42 and solubilityPreclinicalUnclearPoor ADME (Rynearson et al., 2016)
Cpd134Decreasing Aβ42 in cell-based assayPreclinicalUnclearCardiac toxicity potential (Rynearson et al., 2020)
Cpd135Inhibition of Aβ42PreclinicalUnclearCYP3A4 inhibition (Shi J. et al., 2016)
Cpd136Decreasing Aβ42PreclinicalUnclearLimited in vivo activity and poor drug-like properties (Wu et al., 2016)
FRM-36143Decrease Aβ42 and elevations in Aβ38 and Aβ37 (Bursavich et al., 2017; )PreclinicalUnclearNo reports
FRM-024Improved Aβ42 reduction (Bursavich et al., 2021)PreclinicalUnclearNo reports
Cpd142Improved Aβ42 reduction (Zhao et al., 2017)PreclinicalUnclearNo reports
Cpd143Improved Aβ42 reduction (Fischer et al., 2015)PreclinicalUnclearOff-target effects
PF-06442609Potent Aβ42 lowering activity (Pettersson et al., 2015)PreclinicalUnclearNo reports
Cpd145Aβ42 reduction (Pettersson et al., 2017)PreclinicalUnclearNo reports
BI-1408Aβ42 reduction (Gerlach et al., 2018)PreclinicalUnclearNo reports
Cpd147Lowering Aβ42 accumulationinvitroandinvivo (Takai et al., 2015)PreclinicalUnclearNo reports
Cpd149Effectively inhibiting Ab42 (Murakami et al., 2016)PreclinicalUnclearNo reports
RO7101556Potent in vitro and in vivo activity (Rodríguez Sarmiento et al., 2020)PreclinicalUnclearNo reports
Cpd152Lack of in vivo efficacy (Sekioka et al., 2018)PreclinicalUnclearNo reports
Cpd153Efficacious Ab42 lowering (Sekioka et al., 2020b)PreclinicalUnclearNo reports
Cpd154Potent Ab42 inhibition in vitro and in vivo (Sekioka et al., 2020a)PreclinicalUnclearNo reports
Cpd165Potent Ab42 in vitro and in vivo lowering ()PreclinicalUnclearNo reports
D-PinitolAltering APP processing pathways reduces Aβ42 production while avoiding interference with Notch signaling (López-Sánchez et al., 2018)PreclinicalUnclearNo reports
2,5-disubstituted 2-benzylidene hexanoic acid derivativesact as dual γ-secretase/PPARγ modulators in the low micromolar range (Hieke et al., 2011)PreclinicalUnclearNo reports
1,2,3-C-aryl-triazolesGood modulation of γ-secretase activity, excellent pharmacokinetics, and reduced central Aβ42 levels in Sprague-Dawley rats (Fischer et al., 2011)PreclinicalUnclearNo reports
Compound 10 hDecreasing the level of Aβ42 in plasma, CSF, and brain, with little effect on the level of Aβ40 (Hawkins et al., 2011)PreclinicalUnclearNo reports
IminoheterocyclesLowering Aβ42 levels in various in vivo models (Caldwell et al., 2010)PreclinicalUnclearNo reports

The existing γ-secretase modulators (GSMs).

4.2 γ-secretase modulatory proteins (GSMPs)

The aggregation of Aβ-monomers forms the amyloid plaques observed in Alzheimer patients’ brains, which is the key factor in AD (Selkoe, 2013). Increasing evidence has suggested that γ-secretase and its associated proteins could participate in regulating AD, but direct inhibition of γ-secretase has no significant effect on reducing Aβ accumulation and improving cognition in AD’s patients (Shi and Holtzman, 2018). γ-secretase has been a key target for drugs as it facilitates the final cleavages in the production of Aβ. Due to severe adverse effects in clinical trials, GSIs have been discontinued. GSMPs are more secure. It has high efficiency and good safety. Targeting GSMPs can selectively regulate the APP pathway and has tremendous applicability prospects in the treatment of AD. Nowadays, several GSMPs that are closely related to the APP signaling pathway, such as GSAP (Kim et al., 2024; Jin et al., 2022), IFITM3 (Hur, 2021), transmembrane trafficking protein, 21-KD (TMP21) (Ílgün and Çakir, 2025), and stress-associated endoplasmic reticulum protein 1 (SERP1) (Jung et al., 2020). We review the results of a Pubmed search for the keywords “gamma secretase AND (γ-secretase modulatory proteins OR GSMP)” and review recent advances in GSMPs.

4.2.1 γ-secretase activating protein (GSAP)

Lots of γ-secretase interacting proteins have been identified through LCMS analysis. The GSAP was identified as a γ-secretase-interacting partner (Teranishi et al., 2010; Frykman et al., 2012), it could form a complex with γ-secretase and APP-CTF, and an SNP in GSAP has been discovered to be associated with Alzheimer’s disease, giving genetic evidence that links GSAP to AD susceptibility (He et al., 2010). Studies have shown that the inhibition of GSAP can reduce Aβ production without affecting the other key γ-secretase substrates (Kim et al., 2024). GSAP does not interact with Notch, nor does it affect its cleavage (He et al., 2010; Wong et al., 2019). Knockdown of GSAP could reduce Aβ burden and plaque development in the AD model transgenic mice (Kim et al., 2024; He et al., 2010). GSAP specifically promotes γ-secretase–mediated cleavage of APP, the 16-kDa C-terminal fragment of GSAP (GSAP-16K) exerts dual modulation on γ-secretase cleavage: GSAP-16K in dilute phase increases C99 cleavage toward preferred production of Aβ42, but GSAP-16K condensates reduce APP-C99 cleavage through substrate sequestration (Jin et al., 2022). Imatinib is a commonly used anti-cancer drug in the clinic, multiple evidence indicates that imatinib inhibits Aβ but has no effect on Notch signaling (He et al., 2010; Netzer et al., 2003). In AD mouse models, imatinib prevents GSAP from interacting with APP-CTF, thereby reducing Aβ levels and tau phosphorylation (Chu et al., 2014). However, due to the extremely poor BBB penetration ability of imatinib (Brahmachari et al., 2017), it has not yet been applied in Phase II and Phase III clinical trials. Administration of the dimerization of Lep9R3LC (diLep9R3LC) peptide and GSAP siRNA complexes in AD mice can reduce GSAP in the cortex/hippocampus, inhibit Aβ accumulation, reduce tau hyperphosphorylation, and improve cognitive function in AD mice (Kim et al., 2024). In neurons, GSAP interacts with the Fe65–APP complex to modulate APP phosphorylation and its trafficking/partitioning (Xu et al., 2021). Reducing GSAP levels diminishes the partitioning of APP-CTF into lipid rafts, specifically at the mitochondria-associated membrane (MAM), and also decreases γ-secretase activity involved in Aβ production, and decreasing GSAP expression mitigates pathological effects linked to AD (Xu et al., 2021). In addition to contributing to amyloid formation in the brain, GSAP can also promote end-organ dysfunction after bacterial pneumonia. Infection with Pseudomonas aeruginosa caused arterial hypoxemia in wild-type rats, but the integrity of the alveolar-capillary barrier was preserved in GSAP knockout rats. Additionally, infection enhanced myocardial infarction after ischemia-reperfusion injury, and this enhancement was eliminated in the GSAP knockout rats (Gwin et al., 2023). This result sheds light on the role of GSAP in innate immunity and highlights the contribution of GSAP to end-organ dysfunction during infection. However, even if GSAP can serve as an amyloid-beta-lowering therapeutic target without affecting other key functions of γ-secretase, but whether it also acts on other substrates and whether its regulation causes other side effects remains to be investigated.

4.2.2 Interferon-induced transmembrane protein 3 (IFITM3)

Interferon-induced transmembrane protein 3 is one of the members of the IFITMs family, as interferon-induced genes have been found in human neuroblastoma cells, it is an innate immune response protein involved in preventing the entry of viruses into host cells (; ; Kehs et al., 2025). The Aβ peptides have antimicrobial and antiviral activities as part of the innate immune response in the brain (; ). Hur et al. (2020) performed photo-crosslinking tests using the γ-secretase modulator E2012-BPyne and found that IFITM3 is a γ-secretase interaction protein. By interacting with neighboring IFITMs or other transmembrane proteins, IFITMs inhibit the formation of viral fusion pores and reduce the fluidity of the host membrane, this prevents viral infection (Yao and Yan, 2020). In the context of AD, IFITM3 was significantly reduced in the PSEN1 and PSEN2 double-knockout mice, and similarly, IFITM3 RNAi also reduced γ-secretase activity. Furthermore, IFITM3 directly binds to γ-secretase near the catalytic site and reduces γ-secretase activity for Aβ40 and Aβ42 (Hur et al., 2020). The expression of IFITM3 is significantly higher in patients with Alzheimer’s disease in the temporal cortex, knockout of IFITM3 in AD mouse significantly reduces plaque deposition (Hur et al., 2020). Other studies have shown that the expression of IFITM3 could be upregulated by the human herpes virus 6B, hepatitis C virus and cytokines interferon-γ (IFNγ), IFNα, IL-6, and IL-1β all significantly induce (Gómez-Herranz et al., 2023; Yánez et al., 2020; Jiménez-Munguía et al., 2022), and when infected COVID- 19, young mice showed higher IFITM3 responses and interferon-induced chemokines than older mice (Subramaniam et al., 2024). As an immune response protein, IFITM3 plays an important role in AD and other immune-related diseases. It has been confirmed that IFITM3 can interact with γ-secretase in AD, but whether γ-secretase is also involved in other immune diseases with IFITM3 remains to be confirmed.

4.2.3 Transmembrane trafficking protein, 21-KD (TMP21)

Transmembrane trafficking protein, 21-KD, also known as TMED10, is expressed in most brain regions, with higher expression in neuronal cells (Vetrivel et al., 2008). Transgenic mice with neuron-specific increases in TMP21 expression exhibit postnatal growth retardation and severe neurological issues like tremors, seizures, ataxia, uncoordinated movements, and premature death, complete deletion of TMP21 results in embryonic lethality at very early stages (Denzel et al., 2000; Gong et al., 2011). TMP21 is co-localized with γ-secretase, its expression is decreased in AD, which is consistent with the previous study that Aβ expression is increased when TMP21 is knocked down (Vetrivel et al., 2008; Pardossi-Piquard et al., 2009; Chen et al., 2006). Importantly, TMP21 binds to γ-secretase and specifically modulates APP cleavage at the γ-site, however, it has no effect on Notch cleavage at the ε-site (Vetrivel et al., 2008; Chen et al., 2006; Bromley-Brits and Song, 2012). Moreover, TMP21 reduction impairs APP’s bidirectional transport in the ER/Golgi, which increases the amount of APP that undergoes amyloidogenic cleavage in endocytic compartments and sAPP, Aβ40, and Aβ42 secretion (Vetrivel et al., 2007). Reducing TMP21 can increase GSK3β activity (Zhang et al., 2019), thereby promoting NF-κB-mediated β-site amyloid precursor protein cleaving enzyme 1 (BACE1) expression and activity, which further promotes APP processing and Aβ generation (Ly et al., 2013). A study showed that TMP21 could interact with the murine cytomegalovirus immunoevasin gp40 to facilitate virus immune escape (Ramnarayan et al., 2018; Stützer et al., 2013; Xu et al., 2023; ; Honda et al., 2024), so does TM21 also defend against foreign invasion in AD like IFITM3? This is also one of the directions that can be explored in the future.

4.2.4 Stress-associated endoplasmic reticulum protein 1 (SERP1)

Through a genome-wide screen for regulators of γ-secretase activity, researchers identified that SERP1 promotes Aβ production in cells undergoing endoplasmic reticulum (ER) stress. The carboxyl-terminal domain of SERP1 interacts with the APH1A/NCT subcomplex of γ-secretase. Under ER stress conditions, SERP1 selectively recruits APP into the γ-secretase and enhances the subcellular localization of this complex within lipid rafts, leading to increased Aβ generation. Moreover, in cells exposed to high glucose levels and in diabetic AD model mice, elevated levels of SERP1, enhanced γ-secretase assembly, and increased Aβ production were observed (Jung et al., 2020). APH1A and NCT play a crucial role in stabilization, maturation and substrate recognition of the γ-secretase complex. The binding of SERP1 to this subcomplex may enhance its enzymatic activity by stabilizing the conformation of the complex or facilitating the entry of substrates into the active site. Although SERP1 has been shown to interact with γ-secretase, no atomic-resolution cryo-EM structures of SERP1 in complex with either the full γ-secretase complex or its APH1A/NCT subcomplex have been reported to date. Cryo-EM technology holds the potential to elucidate the molecular details of the SERP1–γ-secretase interaction at the atomic level, which is critical not only for understanding the unique mechanism of SERP1 as a GSMP, but also for guiding the rational design of therapeutics targeting this interaction.

4.3 The other GSMPs

4.3.1 Hif-1α

Hypoxia-inducible factor 1α (Hif-1α) serves as a key transcription factor in the cellular adaptation to hypoxic conditions. It plays critical roles in processes such as angiogenesis, metabolism (Masoud and Li, 2015), embryogenesis, and the development and progression of tumors (Peng and Liu, 2015). Numerous studies have shown that Hif-1α can enhance Notch signaling by binding to and stabilizing the intracellular domain of Notch (NICD), thereby activating downstream Notch target genes. Under hypoxic conditions, the interaction between Hif-1α and Notch is essential for maintaining the undifferentiated state of cells (Gustafsson et al., 2005). To counteract the negative feedback effects of Notch signaling in cancer stem cells, Hif-1α can bind to the promoter region of Hes1, a gene targeted by Notch signaling (Wang et al., 2011). In Drosophila models, Hif-1α has been shown to activate Notch signaling independently of ligand interactions, promoting the survival of Drosophila blood cells (Mukherjee et al., 2011). Additionally, research has demonstrated that hypoxia leads to an increase in Aph1a gene expression, which contributes to the upregulation of γ-secretase activity. This effect is mediated through a Hif-1α response element located within the Aph1a gene promoter (Wang et al., 2006). In breast cancer, Hif-1α no longer performs its canonical role as a transcription factor under hypoxic conditions, but instead interacts directly with γ-secretase regulates its activity for Notch cleavage, and enhances cancer cell migration and metastasis (Villa et al., 2014). Microglia-specific BACE-1 deletion enhances autophagolysosome function and Aβ-induced metabolic reprogramming via PI3K-mTOR-HIF-1α signaling, promoting Aβ degradation (Singh et al., 2022). This demonstrates that Hif-1α plays a significant role in AD; however, the molecular mechanism by which Hif-1α and γ-secretase jointly regulate AD requires further elucidation.

4.3.2 CD 147

Coimmunoprecipitation investigations indicated that CD147, a glycoprotein, also referred to as basigin or EMMPRIN (Gabison et al., 2009). Inhibition of CD147 was found to enhance the production of Aβ-peptides, suggesting its function as a regulatory component of γ-secretase in Aβ generation (Zhou et al., 2005). Additionally, CD147 regulates matrix metalloproteinases and is expressed across various human tissues, contributing to both extracellular matrix degradation and fibrosis. This makes it a promising target for cancer therapy via interactions involving cell-matrix and cell-cell connections (Huang et al., 2023; Gao et al., 2016). CD147 undergoes intramembrane cleavage by γ-secretase at lysine 231, leading to the release of its intracellular domains (ICD). The CD147ICD subsequently relocates to the nucleus, where it activates Notch signaling by binding to Notch promoters (Yong et al., 2019). Elevated levels of nuclear CD147ICD correlate with poorer prognoses in human hepatocellular carcinoma (HCC), with patients exhibiting high CD147ICD expression showing significantly reduced overall survival rates compared to those with low CD147ICD expression (Yong et al., 2019). Depletion of CD147 using RNAi increases Aβ-peptide production without altering γ-secretase or APP substrates. Understanding the molecular mechanisms underlying the interaction between CD147 and γ-secretase could pave the way for developing innovative therapies for Alzheimer’s disease (Zhou et al., 2005).

5 Concluding remarks and future challenges

The γ-secretase complex is universally present in all cells and tissues, and its ability to cleave multiple type I membrane proteins can be likened to “molecular scissors “(Wong et al., 2020). Initially characterized as a proteolytic activity responsible for the cleavage of APP to generate Aβ, γ-secretase has been extensively studied in the context of FAD due to missense mutations in its subunits (Jarrett et al., 1993). The deposition of Aβ peptide plaques in the cerebral cortex represents a hallmark feature of AD patients (Dominguez-Gortaire et al., 2025). The generation of Aβ peptides is not only dependent on γ-secretase activity but is also critically regulated by β-secretase. Following the cleavage of APP by β-secretase at the β-site, a membrane-bound C99 intermediate is formed. This C99 fragment subsequently undergoes further cleavage by γ-secretase to produce Aβ peptides. Thus, β-secretase plays a pivotal role in controlling the production of Aβ (Cervellati et al., 2021). In AD, β-secretase expression and activity are significantly increased, contributing to excessive Aβ production (Vassar, 2012). β-secretase inhibitors (BSIs) could reduce Aβ40 and Aβ42 levels effectively (Eketjäll et al., 2016). However, β-secretase has dual roles in Aβ, both in its production and degradation. When β-secretase is highly expressed, low-dose inhibitors may instead lead to an increase in Aβ42 and Aβ40 levels, as the Aβ-degrading activity of β-secretase is preferentially weakened (Ulku et al., 2024). Several BSIs have advanced to phase III clinical trials, but none have shown clear clinical benefits. For example, Verubecestat caused reversible cognitive decline (Vassar, 2012); Atabecestat led to dose-dependent liver enzyme elevation (Pleen and Townley, 2022; Evin et al., 2011); Lanabecestat was linked to psychiatric events, weight loss, and skin depigmentation (Patel et al., 2022); and Elenbecestat resulted in dizziness, nightmares, elevated liver enzymes, and hippocampal atrophy Elenbecestat (Patel et al., 2022). Despite the setbacks encountered in phase III clinical trials, the involvement of β-secretase in AD pathology remains widely acknowledged. The complexity of AD pathogenesis and the potential off-target effects of BSIs are considered critical contributors to the development of adverse drug reactions.

After β-secretase cleaves APP, γ-secretase subsequently cleaves the resulting C99 fragment to generate Aβ peptides. Recent studies have shown that the formation of Aβ peptide plaques may serve as a defense mechanism against viral attacks (Hur et al., 2020). Thus, it can be hypothesized that under normal physiological conditions, plaques fulfilling their function are subsequently cleared. However, when this clearance process is impaired, it leads to the development of AD. With an increasing number of identified γ-secretase substrates, it has become evident that, in addition to APP, several substrates play critical roles in AD progression (Yin et al., 2025). The limited clinical progress achieved through targeting APP alone suggests that the interplay between these substrates and APP warrants further investigation. Due to the broad substrate specificity of γ-secretase, GSIs inhibit the processing of multiple substrates, leading to significant side effects (Chen et al., 2023). Particularly the Notch pathway, which plays a critical role in essential cellular processes such as stem cell maintenance and proliferation, cell fate determination, and differentiation (Kovall et al., 2017; Kopan and Ilagan, 2009). Inhibition of Notch has been associated with gastrointestinal disorders (Hur, 2022; ); lymphopenia and an elevated risk of infection (Doody et al., 2013; Wong et al., 2004), cognitive decline (Doody et al., 2013), and an increased incidence of skin cancer (Uddin et al., 2020). Recent evidence indicates that γ-secretase inhibitors can impair epithelial cell function, leading to colitis in mice (Erkert et al., 2025). Compared to GSIs, GSMs offer more precise modulation of the γ-secretase cleavage site. They shift the cleavage position within the APP transmembrane region, leading to a decrease in Aβ42 levels and a relative increase in Aβ37 and Aβ38 (Figure 4). This approach provides several benefits over GSIs, including the selective reduction of Aβ42 without fully blocking γ-secretase activity, thereby minimizing adverse effects on Notch signaling and allowing for an expanded therapeutic range. Subsequent research uncovered that γ-secretase exhibits distinct localization patterns within tissues and performs specific functions in various cell types (Houser et al., 2023; Strope and Wilkins, 2023; Kwak et al., 2022). These findings raise questions regarding whether γ-secretase activity is regulated by other proteins or signaling pathways. Studies have demonstrated that only a fraction of the γ-secretase complex possesses catalytic activity, and the regulation of this activity remains an open question. GSMPs have emerged as key regulators of γ-secretase activity and specificity, enabling rapid responses to cellular signals and environmental changes (). Multiple GSMPs direct the ubiquitous γ-secretase to initiate appropriate signaling under specific conditions. Notably, GSMPs do not directly inhibit γ-secretase activity but instead modulate it, thereby targeting GMSPs to treat AD may mitigate adverse reactions. BSIs, GSIs, GSMs, and GSMPs can all play a certain role in targeting Aβ deposition. The research progress among them is summarized in Table 3.

TABLE 3

CategoryMechanismAdvantageSide effectsClinical progression
β-secretase inhibitorInhibiting BACE1, blocking APP cleavage at the β-site, and reducing Aβ peptide production.Significantly reduce Aβ levels in cerebrospinal fluid and theoretically inhibit Aβ production.Hepatotoxicity and cognitive side effects, affecting other BACE1 substratesPhase III clinical trials were partially terminated (Chen et al., 2017; Schenk et al., 2012; )
γ-secretase inhibitorDirectly inhibit γ-secretase activity, block the cleavage of all γ-secretase substrates.Rapidly reduce total Aβ levels, including Aβ42.Gastrointestinal toxicity, immunosuppression, and increased skin cancer risk due to Notch pathway inhibition.Phase III clinical trials were terminated due to toxicity/ineffectiveness (Hur, 2022; Wolfe, 2012)
γ-secretase modulatorsAllosteric modulation of γ-secretase selectively reduces Aβ42 and enhances Aβ37/38 levels without affecting total Aβ or other substrates.Avoid Notch-related toxicity, preserve γ-secretase function.Early-generation GSMs: poor brain penetration, low efficacy, a narrow therapeutic window, and failed to improve cognition in Phase III trials.First-generation: failed; Second-generation: some toxicity; New GSMs: preclinical studies (Ji-Yeun, 2022; Raven et al., 2017)
γ-secretase modulatory proteinsRegulating γ-secretase activity or localization, affects Aβ generation.High targeting specificity; reduces Aβ42 without affecting NotchComplex mechanism, preclinical test, lack clinical validation.Preclinical studies, no clinical trials (Kehs et al., 2025; Luo and Li, 2022).

The comparison of β-secretase 1 inhibitors, γ-secretase inhibitors (GSIs), γ-secretase modulators (GSMs), and γ-secretase modulatory proteins (GSMPs) in Alzheimer’s disease (AD).

Research on γ-secretase still faces numerous challenges. For example, the mechanism by which GSMs interact with γ-secretase remains unclear. While most studies suggest that GSMs target the PSEN subunit of γ-secretase (Yang et al., 2021), alternative hypotheses propose the formation of a GSM-substrate-γ-secretase ternary complex (Petit et al., 2022). This uncertainty regarding the molecular target hampers the effective optimization of lead compounds. Furthermore, several GSMs have been discontinued from clinical development due to poor BBB penetration and safety concerns such as adverse side effects (Rynearson et al., 2021; Green et al., 2009). These failures underscore the translational gap between animal models and human trials. In addition, the physiological roles of GSM-regulated Aβ37/Aβ38 peptides in humans remain poorly understood, and their potential to cause unintended effects is still undetermined. Furthermore, studies on GSMPs are at an early stage but face multiple challenges. These include determining their precise cellular localization across different cell types, elucidating the mechanisms underlying substrate selectivity, and understanding how specific GSMP subtypes influence substrate processing. Moreover, as protein-based therapeutics, GSMPs are generally large and struggle to cross the BBB, and exogenous proteins may provoke immune responses, compromising both safety and therapeutic efficacy. Finally, biopharmaceuticals typically involve high production costs, complex manufacturing processes, and lower stability compared to small-molecule drugs. Currently, most research efforts are focused on small-molecule GSMs. In contrast, GSMPs represent a promising yet underexplored therapeutic avenue, with unique mechanisms and development hurdles that warrant further investigation. Addressing these gaps could significantly advance our understanding of γ-secretase biology in disease contexts, potentially leading to therapies with improved safety profiles and greater efficacy.

Statements

Author contributions

GN: Funding acquisition, Supervision, Writing – review & editing, Software, Project administration, Writing – original draft, Visualization, Conceptualization. XF: Software, Writing – original draft. DJ: Writing – review & editing. Zw: Writing – original draft. WS: Writing – review & editing, Writing – original draft. CM: Software, Writing – review & editing. DX: Writing – review & editing. QY: Software, Writing – original draft.

Funding

The author(s) declare that financial support was received for the research and/or publication of this article. This work was supported by National Natural Science Foundation of China (Grant Nos. 32360162 and 32460232), Scientific Research Project of Shaanxi Provincial Department of Education (Grant No. 23JK0732), Scientific research project of Yan’an University (Grant No. YDQ2017-25), Doctoral Research Project of Yan’an University (Grant Nos. YDBK 2023-30 and YDBK2019-56), Shaanxi Provincial College Student Innovation Project (Grant No. S202410719094), Science and Technology Plan Project of Yan’an (Grant No. 2023-SFGG-098), and Yan’an Science and Technology Association Youth Talent Lifting Program Project (Grant No. 2023-20-1). Innovation program of university students (Grant No. D2024054)

Acknowledgments

We acknowledge the financial support provided by the project and express gratitude to the authors for their efforts.

Conflict of interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Generative AI statement

The authors declare that no Generative AI was used in the creation of this manuscript.

Any alternative text (alt text) provided alongside figures in this article has been generated by Frontiers with the support of artificial intelligence and reasonable efforts have been made to ensure accuracy, including review by the authors wherever possible. If you identify any issues, please contact us.

Publisher’s note

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.

References

  • 1

    AbdallahA. (2024). Review on anti-Alzheimer drug development: Approaches, challenges and perspectives.RSC Adv.1411057–11088. 10.1039/d3ra08333k

  • 2

    AbisambraJ.FiorelliT.PadmanabhanJ.NeameP.WefesI.PotterH. (2010). LDLR expression and localization are altered in mouse and human cell culture models of Alzheimer’s disease.PLoS One5:e8556. 10.1371/journal.pone.0008556

  • 3

    AdnanM.AnwarS.DasGuptaD.PatelM.ElasbaliA.AlhassanH.et al (2023). Targeting inhibition of microtubule affinity regulating kinase 4 by harmaline: Strategy to combat Alzheimer’s disease.Int. J. Biol. Macromol.224188–195. 10.1016/j.ijbiomac.2022.10.115

  • 4

    AhnJ.CarrieriC.Dela CruzF.FullertonT.Hajos-KorcsokE.HeP.et al (2020). Pharmacokinetic and pharmacodynamic effects of a γ-secretase Modulator, PF-06648671, on CSF amyloid-β peptides in randomized phase I studies.Clin. Pharmacol. Ther.107211–220. 10.1002/cpt.1570

  • 5

    Amini-Bavil-OlyaeeS.ChoiY.LeeJ.ShiM.HuangI.FarzanM.et al (2013). The antiviral effector IFITM3 disrupts intracellular cholesterol homeostasis to block viral entry.Cell Host Microbe13452–464. 10.1016/j.chom.2013.03.006

  • 6

    AmirradF.BousoikE.ShamlooK.Al-ShiyabH.NguyenV.Montazeri AliabadiH. (2017). Alzheimer’s disease: Dawn of a new era?J. Pharm. Pharm. Sci.20184–225. 10.18433/J3VS8P

  • 7

    AnderssonC.HanssonO.MinthonL.AndreasenN.BlennowK.ZetterbergH.et al (2016). A genetic variant of the sortilin 1 gene is associated with reduced risk of Alzheimer’s disease.J. Alzheimers Dis.531353–1363. 10.3233/JAD-160319

  • 8

    AnnaertW.LevesqueL.CraessaertsK.DierinckI.SnellingsG.WestawayD.et al (1999). Presenilin 1 controls gamma-secretase processing of amyloid precursor protein in pre-golgi compartments of hippocampal neurons.J. Cell Biol.147277–294. 10.1083/jcb.147.2.277

  • 9

    AntonyD.ShethP.SwensonA.SmollerC.MaguireK.GrossbergG. (2025). Recent advances in Alzheimer’s disease therapy: Clinical trials and literature review of novel enzyme inhibitors targeting amyloid precursor protein.Expert Opin. Pharmacother.2663–73. 10.1080/14656566.2024.2438317

  • 10

    AnwarS.ChoudhuryA.HussainA.AlAjmiM.HassanM.IslamA. (2024). Harnessing memantine in Alzheimer’s disease therapy through inhibition of microtubule affinity-regulating kinase: Mechanistic insights.Int. J. Biol. Macromol.262:130090. 10.1016/j.ijbiomac.2024.130090

  • 11

    ArakiY.MiyagiN.KatoN.YoshidaT.WadaS.NishimuraM.et al (2004). Coordinated metabolism of Alcadein and amyloid beta-protein precursor regulates FE65-dependent gene transactivation.J. Biol. Chem.27924343–24354. 10.1074/jbc.M401925200

  • 12

    Area-GomezE.SchonE. (2016). Mitochondria-associated ER membranes and Alzheimer disease.Curr. Opin. Genet. Dev.3890–96. 10.1016/j.gde.2016.04.006

  • 13

    Area-GomezE.de GroofA.BoldoghI.BirdT.GibsonG.KoehlerC.et al (2009). Presenilins are enriched in endoplasmic reticulum membranes associated with mitochondria.Am. J. Pathol.1751810–1816. 10.2353/ajpath.2009.090219

  • 14

    BaileyC.ZhongG.HuangI.FarzanM. (2014). IFITM-family proteins: The cell’s first line of antiviral defense.Annu. Rev. Virol.1261–283. 10.1146/annurev-virology-031413-085537

  • 15

    BarrettP.SandersC.KaufmanS.MichelsenK.JordanJ. B. (2011). NSAID-based γ-secretase modulators do not bind to the amyloid-β polypeptide.Biochemistry5010328–10342. 10.1021/bi201371j

  • 16

    BarrosM.HoulihanW.ParesiC.BrendelM.RynearsonK.LeeC.et al (2020). γ-Secretase partitioning into lipid bilayers remodels membrane microdomains after direct insertion.Langmuir366569–6579. 10.1021/acs.langmuir.0c01178

  • 17

    BatemanR.SiemersE.MawuenyegaK.WenG.BrowningK.SigurdsonW.et al (2009). A gamma-secretase inhibitor decreases amyloid-beta production in the central nervous system.Ann. Neurol.6648–54. 10.1002/ana.21623

  • 18

    BeherD.FrickerM.NadinA.ClarkeE.WrigleyJ.LiY.et al (2003). In vitro characterization of the presenilin-dependent gamma-secretase complex using a novel affinity ligand.Biochemistry428133–8142. 10.1021/bi034045z

  • 19

    BenoitM.HernandezM.DinhM.BenaventeF.VasquezO.TennerA. (2013). C1q-induced LRP1B and GPR6 proteins expressed early in Alzheimer disease mouse models, are essential for the C1q-mediated protection against amyloid-β neurotoxicity.J. Biol. Chem.288654–665. 10.1074/jbc.M112.400168

  • 20

    BergmanA.HanssonE.PursgloveS.FarmeryM.LannfeltL.LendahlU.et al (2004). Pen-2 is sequestered in the endoplasmic reticulum and subjected to ubiquitylation and proteasome-mediated degradation in the absence of presenilin.J. Biol. Chem.27916744–16753. 10.1074/jbc.M313999200

  • 21

    BischoffF.VelterA.MinneG.PietersS.BerthelotD.De CleynM.et al (2019). Design and synthesis of a novel series of cyanoindole derivatives as potent γ-secretase modulators.Bioorg. Med. Chem. Lett.291737–1745. 10.1016/j.bmcl.2019.05.023

  • 22

    BlainJ.BursavichM.FreemanE.HrdlickaL.HodgdonH.ChenT.et al (2016). Characterization of FRM-36143 as a new γ-secretase modulator for the potential treatment of familial Alzheimer’s disease.Alzheimers Res. Ther.8:34. 10.1186/s13195-016-0199-5

  • 23

    BoyK.GuernonJ.ZuevD.XuL.ZhangY.ShiJ.et al (2019). Identification and preclinical evaluation of the bicyclic pyrimidine γ-secretase modulator BMS-932481.ACS Med. Chem. Lett.10312–317. 10.1021/acsmedchemlett.8b00541

  • 24

    BrahmachariS.KaruppagounderS.GeP.LeeS.DawsonV.DawsonT.et al (2017). c-Abl and Parkinson’s disease: Mechanisms and therapeutic potential.J. Parkinsons Dis.7589–601. 10.3233/JPD-171191

  • 25

    BrancaC.SarnicoI.RuotoloR.LanzillottaA.ViscomiA.BenareseM.et al (2014). Pharmacological targeting of the β-amyloid precursor protein intracellular domain.Sci. Rep.4:4618. 10.1038/srep04618

  • 26

    BrogdenR.HeelR.SpeightT.AveryG. (1978). Sulindac: A review of its pharmacological properties and therapeutic efficacy in rheumatic diseases.Drugs1697–114. 10.2165/00003495-197816020-00001

  • 27

    Bromley-BritsK.SongW. (2012). The role of TMP21 in trafficking and amyloid-β precursor protein (APP) processing in Alzheimer’s disease.Curr. Alzheimer Res.9411–424. 10.2174/156720512800492521

  • 28

    BuechlerJ.SalinasP. (2018). Deficient Wnt signaling and synaptic vulnerability in Alzheimer’s disease: Emerging roles for the LRP6 receptor.Front. Synapt. Neurosci.10:38. 10.3389/fnsyn.2018.00038

  • 29

    BulicB.NessJ.HahnS.RennhackA.JumpertzT.WeggenS. (2011). Chemical biology, molecular mechanism and clinical perspective of γ-secretase modulators in Alzheimer’s disease.Curr. Neuropharmacol.9598–622. 10.2174/157015911798376352

  • 30

    BursavichM.HarrisonB.AcharyaR.CostaD.FreemanE.HodgdonH.et al (2017). Design, synthesis, and evaluation of a novel series of oxadiazine gamma secretase modulators for familial Alzheimer’s disease.J. Med. Chem.602383–2400. 10.1021/acs.jmedchem.6b01620

  • 31

    BursavichM.HarrisonB.AcharyaR.CostaD.FreemanE.HrdlickaL.et al (2021). Discovery of the oxadiazine FRM-024: A potent CNS-penetrant gamma secretase modulator.J. Med. Chem.6414426–14447. 10.1021/acs.jmedchem.1c00904

  • 32

    CaldwellA.LiuQ.ZhangC.SchrothG.GalaskoD.RynearsonK.et al (2022). Endotype reversal as a novel strategy for screening drugs targeting familial Alzheimer’s disease.Alzheimers Dement.182117–2130. 10.1002/alz.12553

  • 33

    CaldwellJ.BennettC.McCrackenT.MazzolaR.BaraT.BuevichA.et al (2010). Iminoheterocycles as gamma-secretase modulators.Bioorg. Med. Chem. Lett.205380–5384. 10.1016/j.bmcl.2010.07.121

  • 34

    CervellatiC.ValacchiG.ZulianiG. (2021). BACE1: From biomarker to Alzheimer’s disease therapeutical target.Aging1312299–12300. 10.18632/aging.203064

  • 35

    ChaudhuryA.GereckeK.WyssJ.MorganD.GordonM.CarrollS. (2003). Neuregulin-1 and erbB4 immunoreactivity is associated with neuritic plaques in Alzheimer disease brain and in a transgenic model of Alzheimer disease.J. Neuropathol. Exp. Neurol.6242–54. 10.1093/jnen/62.1.42

  • 36

    ChenF.HasegawaH.Schmitt-UlmsG.KawaraiT.BohmC.KatayamaT.et al (2006). TMP21 is a presenilin complex component that modulates gamma-secretase but not epsilon-secretase activity.Nature4401208–1212. 10.1038/nature04667

  • 37

    ChenG.XuT.YanY.ZhouY.JiangY.MelcherK.et al (2017). Amyloid beta: Structure, biology and structure-based therapeutic development.Acta Pharmacol. Sin.381205–1235. 10.1038/aps.2017.28

  • 38

    ChenS.KochM.Chávez-GutiérrezL.ZachariasM. (2023). How modulator binding at the Amyloidβ-γ-secretase interface enhances substrate binding and attenuates membrane distortion.J. Med. Chem.6616772–16782. 10.1021/acs.jmedchem.3c01480

  • 39

    ChenX.BeckerA.AlbayR.NguyenP.KarachentsevD.RobertsA.et al (2024). γ-secretase modulator BPN15606 reduced Aβ42 and Aβ40 and countered alzheimer-related pathologies in a mouse model of down syndrome.Ann. Neurol.96390–404. 10.1002/ana.26958

  • 40

    ChenZ.SimmonsM.PerryR.WienerH.HarrellL.GoR. (2008). Genetic association of neurotrophic tyrosine kinase receptor type 2 (NTRK2) With Alzheimer’s disease.Am. J. Med. Genet. B Neuropsychiatr. Genet.147363–369. 10.1002/ajmg.b.30607

  • 41

    ChhibberJ. (2013). Identification and characterization of innate immune receptor substrates of γ-secretase enzyme complex.Cork: University College Cork.

  • 42

    Chhibber-GoelJ.Coleman-VaughanC.AgrawalV.SawhneyN.HickeyE.PowellJ.et al (2016). γ-Secretase activity is required for regulated intramembrane proteolysis of tumor necrosis factor (TNF) receptor 1 and TNF-mediated pro-apoptotic signaling.J. Biol. Chem.2915971–5985. 10.1074/jbc.M115.679076

  • 43

    ChoiJ.ChoS.ParkJ.YunS.JoC.KimE.et al (2020). Elevated cerebrospinal fluid and plasma N-cadherin in Alzheimer disease.J. Neuropathol. Exp. Neurol.79484–492. 10.1093/jnen/nlaa019

  • 44

    ChuJ.LaurettiE.CraigeC.PraticòD. (2014). Pharmacological modulation of GSAP reduces amyloid-β levels and tau phosphorylation in a mouse model of Alzheimer’s disease with plaques and tangles.J. Alzheimers Dis.41729–737. 10.3233/JAD-140105

  • 45

    ChungH.StruhlG. (2002). Nicastrin is required for presenilin-mediated transmembrane cleavage in Drosophila.Nat. Cell Biol.31129–1132. 10.1038/ncb1201-1129

  • 46

    ColomboA.HsiaH.WangM.KuhnP.BrillM.CanevazziP.et al (2018). Non-cell-autonomous function of DR6 in Schwann cell proliferation.EMBO J.37:e97390. 10.15252/embj.201797390

  • 47

    CrystalA.MoraisV.PiersonT.PijakD.CarlinD.LeeV.et al (2003). Membrane topology of gamma-secretase component PEN-2.J. Biol. Chem.27820117–20123. 10.1074/jbc.M213107200

  • 48

    de JongD.JansenR.HoefnagelsW.Jellesma-EggenkampM.VerbeekM.BormG.et al (2008). No effect of one-year treatment with indomethacin on Alzheimer’s disease progression: A randomized controlled trial.PLoS One3:e1475. 10.1371/journal.pone.0001475

  • 49

    De StrooperB.KarranE. (2024). New precision medicine avenues to the prevention of Alzheimer’s disease from insights into the structure and function of γ-secretases.EMBO J.43887–903. 10.1038/s44318-024-00057-w

  • 50

    De StrooperB.SaftigP.CraessaertsK.VandersticheleH.GuhdeG.AnnaertW.et al (1998). Deficiency of presenilin-1 inhibits the normal cleavage of amyloid precursor protein.Nature391387–390. 10.1038/34910

  • 51

    DenzelA.OttoF.GirodA.PepperkokR.WatsonR.RosewellI.et al (2000). The p24 family member p23 is required for early embryonic development.Curr. Biol.1055–58. 10.1016/s0960-9822(99)00266-3

  • 52

    DevkotaS.WilliamsT.WolfeM. (2021). Familial Alzheimer’s disease mutations in amyloid protein precursor alter proteolysis by γ-secretase to increase amyloid β-peptides of ≤45 residues.J. Biol. Chem.296:100281. 10.1016/j.jbc.2021.100281

  • 53

    DiBattistaA.DumanisS.NewmanJ.RebeckG. (2016). Identification and modification of amyloid-independent phenotypes of APOE4 mice.Exp. Neurol.28097–105. 10.1016/j.expneurol.2016.04.014

  • 54

    DietrichM.AntequeraD.PascualC.CastroN.BolosM.CarroE. (2014). Alzheimer’s disease-like impaired cognition in endothelial-specific megalin-null mice.J. Alzheimers Dis.39711–717. 10.3233/JAD-131604

  • 55

    Dominguez-GortaireJ.RuizA.Porto-PazosA.Rodriguez-YanezS.CedronF. (2025). Alzheimer’s disease: Exploring pathophysiological hypotheses and the role of machine learning in drug discovery.Int. J. Mol. Sci.26:1004. 10.3390/ijms26031004

  • 56

    DoodyR.RamanR.FarlowM.IwatsuboT.VellasB.JoffeS.et al (2013). A phase 3 trial of semagacestat for treatment of Alzheimer’s disease.N. Engl. J. Med.369341–350. 10.1056/NEJMoa1210951

  • 57

    DriesD.YuG. (2008). Assembly, maturation, and trafficking of the gamma-secretase complex in Alzheimer’s disease.Curr. Alzheimer Res.5132–146. 10.2174/156720508783954695

  • 58

    DriesD.YuG. (2021). Breathing new life into the rational design of Alzheimer’s therapeutics.Cell184296–298. 10.1016/j.cell.2020.12.036

  • 59

    DriesD.ShahS.HanY.YuC.YuS.ShearmanM.et al (2009). Glu-333 of nicastrin directly participates in gamma-secretase activity.J. Biol. Chem.28429714–29724. 10.1074/jbc.M109.038737

  • 60

    EggertS.PaligaK.SobaP.EvinG.MastersC.WeidemannA.et al (2004). The proteolytic processing of the amyloid precursor protein gene family members APLP-1 and APLP-2 involves alpha-, beta-, gamma-, and epsilon-like cleavages: Modulation of APLP-1 processing by n-glycosylation.J. Biol. Chem.27918146–18156. 10.1074/jbc.M311601200

  • 61

    EketjällS.JansonJ.KasperssonK.BogstedtA.JeppssonF.FältingJ.et al (2016). AZD3293: A novel, orally active BACE1 inhibitor with high potency and permeability and markedly slow off-rate kinetics.J. Alzheimers Dis.501109–1123. 10.3233/JAD-150834

  • 62

    ElzingaB.TwomeyC.PowellJ.HarteF.McCarthyJ. (2009). Interleukin-1 receptor type 1 is a substrate for gamma-secretase-dependent regulated intramembrane proteolysis.J. Biol. Chem.2841394–1409. 10.1074/jbc.M803108200

  • 63

    EriksenJ.SagiS.SmithT.WeggenS.DasP.McLendonD.et al (2003). NSAIDs and enantiomers of flurbiprofen target gamma-secretase and lower Abeta 42 in vivo.J. Clin. Invest.112440–449. 10.1172/JCI18162

  • 64

    ErkertL.KabischM.Gamez-BelmonteR.Gonzalez-AceraM.PatankarJ.SchödelL.et al (2025). Pharmacological inhibitors of the gamma-secretase enzyme complex disrupt epithelial cell function triggering colitis in mice.J. Crohns Colitis19:jjaf096. 10.1093/ecco-jcc/jjaf096

  • 65

    EvinG.LesseneG.WilkinsS. (2011). BACE inhibitors as potential drugs for the treatment of Alzheimer’s disease: Focus on bioactivity.Recent Pat. CNS Drug Discov.691–106. 10.2174/157488911795933938

  • 66

    FasslerM.ZocherM.KlareS.de la FuenteA. G.ScheuermannJ.CapellA.et al (2005). Masking of transmembrane-based retention signals controls ER export of gamma-secretase.Traffic11250–258. 10.1111/j.1600-0854.2009.01014.x

  • 67

    FeldmanR.ChandlerK.LevyL.GlaserG. H. (1963). Familial Alzheimer’s disease.Neurology13811–824. 10.1212/wnl.13.10.811

  • 68

    FischerC.ZultanskiS.ZhouH.MethotJ.BrownW.MampreianD.et al (2011). Triazoles as γ-secretase modulators.Bioorg. Med. Chem. Lett.214083–4087. 10.1016/j.bmcl.2011.04.089

  • 69

    FischerC.ZultanskiS.ZhouH.MethotJ.ShahS.HayashiI.et al (2015). Discovery of novel triazolobenzazepinones as γ-secretase modulators with central Aβ42 lowering in rodents and rhesus monkeys.Bioorg. Med. Chem. Lett.253488–3494. 10.1016/j.bmcl.2015.07.003

  • 70

    FluhrerR.FriedleinA.HaassC.WalterJ. (2004). Phosphorylation of presenilin 1 at the caspase recognition site regulates its proteolytic processing and the progression of apoptosis.J. Biol. Chem.2791585–1593. 10.1074/jbc.M306653200

  • 71

    FoncinJ.SalmonD.Supino-ViterboV.FeldmanR.MacchiG.MariottiP.et al (1985). [Alzheimer’s presenile dementia transmitted in an extended kindred].Rev. Neurol.141194–202.

  • 72

    FraeringP.LaVoieM.YeW.OstaszewskiB.KimberlyW.SelkoeD.et al (2004). Detergent-dependent dissociation of active gamma-secretase reveals an interaction between Pen-2 and PS1-NTF and offers a model for subunit organization within the complex.Biochemistry43323–333. 10.1021/bi035748j

  • 73

    FrancisR.McGrathG.ZhangJ.RuddyD.SymM.ApfeldJ.et al (2002). Aph-1 and pen-2 are required for Notch pathway signaling, gamma-secretase cleavage of betaAPP, and presenilin protein accumulation.Dev. Cell385–97. 10.1016/s1534-5807(02)00189-2

  • 74

    FraserP.LevesqueG.YuG.MillsL.ThirlwellJ.FrantsevaM.et al (1998). Presenilin 1 is actively degraded by the 26S proteasome.Neurobiol. Aging19S19–S21. 10.1016/s0197-4580(98)00029-3

  • 75

    FreudeS.SchilbachK.SchubertM. (2009). The role of IGF-1 receptor and insulin receptor signaling for the pathogenesis of Alzheimer’s disease: From model organisms to human disease.Curr. Alzheimer Res.6213–223. 10.2174/156720509788486527

  • 76

    FrostG.JonasL.LiY. (2019). Friend, foe or both? Immune activity in Alzheimer’s disease.Front. Aging Neurosci.11:337. 10.3389/fnagi.2019.00337

  • 77

    FrykmanS.TeranishiY.HurJ.SandebringA.YamamotoN.AncarcronaM.et al (2012). Identification of two novel synaptic γ-secretase associated proteins that affect amyloid β-peptide levels without altering Notch processing.Neurochem. Int.61108–118. 10.1016/j.neuint.2012.03.016

  • 78

    FuentealbaR.BarríaM.LeeJ.CamJ.ArayaC.EscuderoC.et al (2007). ApoER2 expression increases Abeta production while decreasing amyloid precursor protein (APP) endocytosis: Possible role in the partitioning of APP into lipid rafts and in the regulation of gamma-secretase activity.Mol. Neurodegener.2:14. 10.1186/1750-1326-2-14

  • 79

    FukumoriA.FluhrerR.SteinerH.HaassC. (2010). Three-amino acid spacing of presenilin endoproteolysis suggests a general stepwise cleavage of gamma-secretase-mediated intramembrane proteolysis.J. Neurosci.307853–7862. 10.1523/JNEUROSCI.1443-10.2010

  • 80

    GabisonE.HuetE.BaudouinC.MenashiS. (2009). Direct epithelial-stromal interaction in corneal wound healing: Role of EMMPRIN/CD147 in MMPs induction and beyond.Prog. Retin. Eye Res.2819–33. 10.1016/j.preteyeres.2008.11.001

  • 81

    GaoC.LuC.ChenJ. (2016). Biological characteristics of cluster of differentiation 147 and its relationship with tumour.Zhongguo Yi Xue Ke Xue Yuan Xue Bao38589–593. 10.3881/j.issn.1000-503X.2016.05.018

  • 82

    GayenM.BenoitM.FanQ.HudobenkoJ.YanR. (2022). The CX3CL1 intracellular domain exhibits neuroprotection via insulin receptor/insulin-like growth factor receptor signaling.J. Biol. Chem.298:102532. 10.1016/j.jbc.2022.102532

  • 83

    GerlachK.HobsonS.EickmeierC.GroßU.BraunC.SiegerP.et al (2018). Discovery of tetrahydroindazoles as a novel class of potent and in vivo efficacious gamma secretase modulators.Bioorg. Med. Chem.263227–3241. 10.1016/j.bmc.2018.04.053

  • 84

    Gómez-HerranzM.TaylorJ.SloanR. D. (2023). IFITM proteins: Understanding their diverse roles in viral infection, cancer, and immunity.J. Biol. Chem.299:102741. 10.1016/j.jbc.2022.102741

  • 85

    GongP.RosemanJ.FernandezC.VetrivelK.BindokasV.ZitzowL.et al (2011). Transgenic neuronal overexpression reveals that stringently regulated p23 expression is critical for coordinated movement in mice.Mol. Neurodegener.6:87. 10.1186/1750-1326-6-87

  • 86

    GoutteC.HeplerW.MickeyK.PriessJ. (2000). Aph-2 encodes a novel extracellular protein required for GLP-1-mediated signaling.Development1272481–2492. 10.1242/dev.127.11.2481

  • 87

    GoutteC.TsunozakiM.HaleV.PriessJ. R. (2002). APH-1 is a multipass membrane protein essential for the Notch signaling pathway in Caenorhabditis elegans embryos.Proc. Natl. Acad. Sci. U.S.A.99775–779. 10.1073/pnas.022523499

  • 88

    GreenR.SchneiderL.AmatoD.BeelenA.WilcockG.SwabbE.et al (2009). Effect of tarenflurbil on cognitive decline and activities of daily living in patients with mild Alzheimer disease: A randomized controlled trial.JAMA3022557–2564. 10.1001/jama.2009.1866

  • 89

    GünerG.LichtenthalerS. (2020). The substrate repertoire of γ-secretase/presenilin.Semin. Cell Dev. Biol.10527–42. 10.1016/j.semcdb.2020.05.019

  • 90

    GunnarN.JohanL.JohanS. (2023). Gamma-secretase modulators: A promising route for the treatment of Alzheimer’s disease.Front. Mol. Neurosci.16:1279740. 10.3389/fnmol.2023.1279740

  • 91

    GustafssonM.ZhengX.PereiraT.GradinK.JinS.LundkvistJ.et al (2005). Hypoxia requires notch signaling to maintain the undifferentiated cell state.Dev. Cell9617–628. 10.1016/j.devcel.2005.09.010

  • 92

    GwinM.AlexeyevM.GeurtsA.LeeJ.ZhouC.YangX.et al (2023). Gamma secretase activating protein promotes end-organ dysfunction after bacterial pneumonia.Am. J. Physiol. Lung Cell Mol. Physiol.325L174–L189. 10.1152/ajplung.00018.2023

  • 93

    HaapasaloA.KovacsD. (2011). The many substrates of presenilin/γ-secretase.J. Alzheimers Dis.253–28. 10.3233/JAD-2011-101065

  • 94

    HakemF.FouadY.ArafaR. (2024). Gamma secretase as an important drug target for management of Alzheimer’s disease: A comprehensive review.Curr. Top. Med. Chem.24109–127. 10.2174/0115680266259174231006070637

  • 95

    HampelH.CaraciF.CuelloA.CarusoG.NisticòR.CorboM.et al (2020). A path toward precision medicine for neuroinflammatory mechanisms in Alzheimer’s disease.Front. Immunol.11:456. 10.3389/fimmu.2020.00456

  • 96

    HataS.FujishigeS.ArakiY.KatoN.ArasekiM.NishimuraM.et al (2009). Alcadein cleavages by amyloid beta-precursor protein (APP) alpha- and gamma-secretases generate small peptides, p3-Alcs, indicating Alzheimer disease-related gamma-secretase dysfunction.J. Biol. Chem.28436024–36033. 10.1074/jbc.M109.057497

  • 97

    HawkinsJ.HarrisonD.AhmedS.DavisR.ChapmanT.MarshallI.et al (2011). Dynamics of Aβ42 reduction in plasma, CSF and brain of rats treated with the γ-secretase modulator, GSM-10h.Neurodegener. Dis.8455–464. 10.1159/000324511

  • 98

    HeG.LuoW.LiP.RemmersC.NetzerW.HendrickJ.et al (2010). Gamma-secretase activating protein is a therapeutic target for Alzheimer’s disease.Nature46795–98. 10.1038/nature09325

  • 99

    HemmingM.EliasJ.GygiS.SelkoeD. (2008). Proteomic profiling of gamma-secretase substrates and mapping of substrate requirements.PLoS Biol.6:e257. 10.1371/journal.pbio.0060257

  • 100

    HiekeM.NessJ.SteriR.GreinerC.WerzO.Schubert-ZsilaveczM.et al (2011). SAR studies of acidic dual γ-secretase/PPARγ modulators.Bioorg. Med. Chem.195372–5382. 10.1016/j.bmc.2011.08.003

  • 101

    HoeH.RebeckG. (2005). Regulation of ApoE receptor proteolysis by ligand binding.Brain Res. Mol. Brain Res.13731–39. 10.1016/j.molbrainres.2005.02.013

  • 102

    HondaK.TakahashiH.HataS.AbeR.SaitoT.SaidoT.et al (2024). Suppression of the amyloidogenic metabolism of APP and the accumulation of Aβ by alcadein α in the brain during aging.Sci. Rep.14:18471. 10.1038/s41598-024-69400-9

  • 103

    HötteckeN. (2010). Entwicklung und Synthese von γ-Sekretase-Modulatoren zur Behandlung von Morbus Alzheimer.Darmstadt: Technischen Universität Darmstadt.

  • 104

    HouX.ZhangX.ZouH.GuanM.FuC.WangW.et al (2023). Differential and substrate-specific inhibition of γ-secretase by the C-terminal region of ApoE2, ApoE3, and ApoE4.Neuron111:1898–1913.e5. 10.1016/j.neuron.2023.03.024

  • 105

    HouserM.MitchellS.SinhaP.LundinB.BerezovskaO.MaesakoM. (2023). Endosome and lysosome membrane properties functionally link to γ-secretase in live/intact cells.Sensors23:2651. 10.3390/s23052651

  • 106

    HuY.YeY.FortiniM. (2002). Nicastrin is required for gamma-secretase cleavage of the Drosophila Notch receptor.Dev. Cell269–78. 10.1016/s1534-5807(01)00105-8

  • 107

    HuangD.RaoD.JinQ.LaiM.ZhangJ.LaiZ.et al (2023). Role of CD147 in the development and diagnosis of hepatocellular carcinoma.Front. Immunol.14:1149931. 10.3389/fimmu.2023.1149931

  • 108

    HurJ. (2021). Innate immunity protein IFITM3 in Alzheimer’s disease.DNA Cell Biol.401351–1355. 10.1089/dna.2021.0585

  • 109

    HurJ. (2022). γ-Secretase in Alzheimer’s disease.Exp. Mol. Med.54433–446. 10.1038/s12276-022-00754-8

  • 110

    HurJ.FrostG.WuX.CrumpC.PanS.WongE.et al (2020). The innate immunity protein IFITM3 modulates γ-secretase in Alzheimer’s disease.Nature586735–740. 10.1038/s41586-020-2681-2

  • 111

    IkeuchiT.SisodiaS. (2003). The Notch ligands, Delta1 and Jagged2, are substrates for presenilin-dependent “gamma-secretase” cleavage.J. Biol. Chem.2787751–7754. 10.1074/jbc.C200711200

  • 112

    ÍlgünA.ÇakirT. (2025). Functional specificity of astrocyte subtypes in Alzheimer’s disease: Decoding disease mechanisms through network-based analysis of integrated single-nuclei multi-omic data.Mol. Neurobiol.10.1007/s12035-025-04965-8[Epub ahead of print].

  • 113

    ImbimboB.SolfrizziV.PanzaF. (2010). Are NSAIDs useful to treat Alzheimer’s disease or mild cognitive impairment?Front. Aging Neurosci.2:19. 10.3389/fnagi.2010.00019

  • 114

    IoppoloA.EcclesM.GrothD.VerdileG.AgostinoM. (2021). Evaluation of virtual screening strategies for the identification of γ-secretase inhibitors and modulators.Molecules27:176. 10.3390/molecules27010176

  • 115

    IsooN.SatoC.MiyashitaH.ShinoharaM.TakasugiN.MorohashiY.et al (2007). Abeta42 overproduction associated with structural changes in the catalytic pore of gamma-secretase: Common effects of Pen-2 N-terminal elongation and fenofibrate.J. Biol. Chem.28212388–12396. 10.1074/jbc.M611549200

  • 116

    JarrettJ.BergerE.LansburyP. (1993). The carboxy terminus of the beta amyloid protein is critical for the seeding of amyloid formation: Implications for the pathogenesis of Alzheimer’s disease.Biochemistry324693–4697. 10.1021/bi00069a001

  • 117

    JensenA.KitagoY.FazeliE.VægterC.SmallS.PetskoG.et al (2023). Dimerization of the Alzheimer’s disease pathogenic receptor SORLA regulates its association with retromer.Proc. Natl. Acad. Sci. U.S.A.120:e2212180120. 10.1073/pnas.2212180120

  • 118

    Jiménez-MunguíaI.BeavenA.BlankP.SodtA.ZimmerbergJ. (2022). Interferon-induced transmembrane protein 3 (IFITM3) and its antiviral activity.Curr. Opin. Struct. Biol.77:102467. 10.1016/j.sbi.2022.102467

  • 119

    JinC.WangJ.WangY.JiaB.GuoX.YangG.et al (2022). Modulation of amyloid precursor protein cleavage by γ-secretase activating protein through phase separation.Proc. Natl. Acad. Sci. U.S.A.119:e2122292119. 10.1073/pnas.2122292119

  • 120

    Ji-YeunH. (2022). γ-Secretase in Alzheimer’s disease.Exp. Mol. Med.54433–446. 10.1038/s12276-022-00754-8

  • 121

    JoannaE. L.Yue-MingL. (2022). Turning the tide on Alzheimer’s disease: Modulation of γ-secretase.Cell Biosci.12:2. 10.1186/s13578-021-00738-7

  • 122

    JonssonT.StefanssonH.SteinbergS.JonsdottirI.JonssonP.SnaedalJ.et al (2013). Variant of TREM2 associated with the risk of Alzheimer’s disease.N. Engl. J. Med.368107–116. 10.1056/NEJMoa1211103

  • 123

    JungS.HyunJ.NahJ.HanJ.KimS.ParkJ.et al (2020). SERP1 is an assembly regulator of γ-secretase in metabolic stress conditions.Sci. Signal.13:eaax8949. 10.1126/scisignal.aax8949

  • 124

    JutrasI.LaplanteA.BoulaisJ.BrunetS.ThinakaranG.DesjardinsM. (2005). Gamma-secretase is a functional component of phagosomes.J. Biol. Chem.28036310–36317. 10.1074/jbc.M504069200

  • 125

    KaetherC.CapellA.EdbauerD.WinklerE.NovakB.SteinerH.et al (2005). The presenilin C-terminus is required for ER-retention, nicastrin-binding and gamma-secretase activity.EMBO J.234738–4748. 10.1038/sj.emboj.7600478

  • 126

    KaetherC.CapellA.EdbauerD.WinklerE.NovakB.SteinerH.et al (2004). The presenilin C-terminus is required for ER-retention, nicastrin-binding and gamma-secretase activity.EMBO J.234738–4748. 10.1038/sj.emboj.7600478

  • 127

    KehsZ.CrossA.LiY. (2025). From defense to disease: IFITM3 in immunity and Alzheimer’s disease.Neurotherapeutics22:e00482. 10.1016/j.neurot.2024.e00482

  • 128

    KimJ.YoonH.BasakJ.KimJ. (2014). Apolipoprotein E in synaptic plasticity and Alzheimer’s disease: Potential cellular and molecular mechanisms.Mol. Cells37767–776. 10.14348/molcells.2014.0248

  • 129

    KimK.GoldbergI.GrahamM.SundaramM.BertaggiaE.LeeS.et al (2018). γ-secretase inhibition lowers plasma triglyceride-rich lipoproteins by stabilizing the LDL receptor.Cell Metab.27:816–827.e4. 10.1016/j.cmet.2018.02.010

  • 130

    KimS.UllahI.BeloorJ.ChungK.KimJ.YiY.et al (2024). Systemic treatment with siRNA targeting gamma-secretase activating protein inhibits amyloid-β accumulation in Alzheimer’s disease.Biomater. Res.28:0027. 10.34133/bmr.0027

  • 131

    KimT.PettingellW.HallmarkO.MoirR.WascoW.TanziR. (1997). Endoproteolytic cleavage and proteasomal degradation of presenilin 2 in transfected cells.J. Biol. Chem.27211006–11010. 10.1074/jbc.272.17.11006

  • 132

    KimT.WuK.XuJ.McAuliffeG.TanziR.WascoW.et al (1995). Selective localization of amyloid precursor-like protein 1 in the cerebral cortex postsynaptic density.Brain Res. Mol. Brain Res.3236–44. 10.1016/0169-328x(95)00328-p

  • 133

    KimuraN.NakamuraS.HondaT.TakashimaA.NakayamaH.OnoF.et al (2001). Age-related changes in the localization of presenilin-1 in cynomolgus monkey brain.Brain Res.92230–41. 10.1016/s0006-8993(01)03146-8

  • 134

    KnopmanD.AmievaH.PetersenR.ChételatG.HoltzmanD.HymanB.et al (2021). Alzheimer disease.Nat. Rev. Dis. Prim.7:33. 10.1038/s41572-021-00269-y

  • 135

    KopanR.IlaganM. (2009). The canonical Notch signaling pathway: Unfolding the activation mechanism.Cell137216–233. 10.1016/j.cell.2009.03.045

  • 136

    KornilovaA.KimJ.LaudonH.WolfeM. (2006). Deducing the transmembrane domain organization of presenilin-1 in gamma-secretase by cysteine disulfide cross-linking.Biochemistry457598–7604. 10.1021/bi060107k

  • 137

    KovallR.GebeleinB.SprinzakD.KopanR. (2017). The canonical notch signaling pathway: Structural and biochemical insights into shape, sugar, and force.Dev. Cell41228–241. 10.1016/j.devcel.2017.04.001

  • 138

    KuoL.HuM.HsuW.TungY.WangB.TsaiW.et al (2008). Tumor necrosis factor-alpha-elicited stimulation of gamma-secretase is mediated by c-Jun N-terminal kinase-dependent phosphorylation of presenilin and nicastrin.Mol. Biol. Cell194201–4212. 10.1091/mbc.e07-09-0987

  • 139

    KwakM.SouthardK.KimW.LinA.KimN.GopalappaR.et al (2022). Adherens junctions organize size-selective proteolytic hotspots critical for Notch signalling.Nat. Cell Biol.241739–1753. 10.1038/s41556-022-01031-6

  • 140

    LaiM.ChenE.CrouthamelM.DiMuzio-MowerJ.XuM.HuangQ.et al (2003). Presenilin-1 and presenilin-2 exhibit distinct yet overlapping gamma-secretase activities.J. Biol. Chem.27822475–22481. 10.1074/jbc.M300974200

  • 141

    LammichS.OkochiM.TakedaM.KaetherC.CapellA.ZimmerA.et al (2002). Presenilin-dependent intramembrane proteolysis of CD44 leads to the liberation of its intracellular domain and the secretion of an Abeta-like peptide.J. Biol. Chem.27744754–44759. 10.1074/jbc.M206872200

  • 142

    LauK.HowlettD.KesavapanyS.StandenC.DingwallC.McLoughlinD.et al (2002). Cyclin-dependent kinase-5/p35 phosphorylates Presenilin 1 to regulate carboxy-terminal fragment stability.Mol. Cell Neurosci.2013–20. 10.1006/mcne.2002.1108

  • 143

    LaVoieM.FraeringP.OstaszewskiB.YeW.KimberlyW.WolfeM.et al (2003). Assembly of the gamma-secretase complex involves early formation of an intermediate subcomplex of Aph-1 and nicastrin.J. Biol. Chem.27837213–37222. 10.1074/jbc.M303941200

  • 144

    LeeS.ShahS.YuC.WigleyW.LiH.LimM.et al (2004). A conserved GXXXG motif in APH-1 is critical for assembly and activity of the gamma-secretase complex.J. Biol. Chem.2794144–4152. 10.1074/jbc.M309745200

  • 145

    Levy-LahadE.WascoW.PoorkajP.RomanoD.OshimaJ.PettingellW.et al (1995). Candidate gene for the chromosome 1 familial Alzheimer’s disease locus.Science269973–977. 10.1126/science.7638622

  • 146

    LiaoJ.ChenC.AhnE.LiuX.LiH.Edgington-MitchellL.et al (2021). Targeting both BDNF/TrkB pathway and delta-secretase for treating Alzheimer’s disease.Neuropharmacology197:108737. 10.1016/j.neuropharm.2021.108737

  • 147

    LingI.GoldeT.GalaskoD.KooE. (2015). Modulation of Aβ42 in vivo by γ-secretase modulator in primates and humans.Alzheimers Res. Ther.7:55. 10.1186/s13195-015-0137-y

  • 148

    LiuC.RanganathanS.RobinsonS.StricklandD. (2007). gamma-Secretase-mediated release of the low density lipoprotein receptor-related protein 1B intracellular domain suppresses anchorage-independent growth of neuroglioma cells.J. Biol. Chem.2827504–7511. 10.1074/jbc.M608088200

  • 149

    LleóA.WaldronE.von ArnimC.HerlL.TangrediM.PeltanI.et al (2005). Low density lipoprotein receptor-related protein (LRP) interacts with presenilin 1 and is a competitive substrate of the amyloid precursor protein (APP) for gamma-secretase.J. Biol. Chem.28027303–27309. 10.1074/jbc.M413969200

  • 150

    López-SánchezJ. L.MorenoD. A.García-ViguerC. (2018). D-pinitol, a highly valuable product from carob pods: Health-promoting effects and metabolic pathways of this natural super-food ingredient and its derivatives.AIMS Agric. Food341–63. 10.3934/agrfood.2018.1.41

  • 151

    LuoJ.LiY. (2022). Turning the tide on Alzheimer’s disease: Modulation of γ-secretase.Cell Biosci.12:2. 10.1186/s13578-021-00738-7

  • 152

    LyP.WuY.ZouH.WangR.ZhouW.KinoshitaA.et al (2013). Inhibition of GSK3β-mediated BACE1 expression reduces Alzheimer-associated phenotypes.J. Clin. Invest.123224–235. 10.1172/JCI64516

  • 153

    MaiaM.SousaE. (2019). BACE-1 and γ-secretase as therapeutic targets for Alzheimer’s disease.Pharmaceuticals12:41. 10.3390/ph12010041

  • 154

    MalvankarS.WolfeM. (2025). γ-secretase-mediated endoproteolysis of neuregulin-1 and E-cadherin.Biochemistry642991–2999. 10.1021/acs.biochem.5c00095

  • 155

    MarambaudP.ShioiJ.SerbanG.GeorgakopoulosA.SarnerS.NagyV.et al (2002). A presenilin-1/gamma-secretase cleavage releases the E-cadherin intracellular domain and regulates disassembly of adherens junctions.EMBO J.211948–1956. 10.1093/emboj/21.8.1948

  • 156

    MarambaudP.WenP.DuttA.ShioiJ.TakashimaA.SimanR.et al (2003). A CBP binding transcriptional repressor produced by the PS1/epsilon-cleavage of N-cadherin is inhibited by PS1 FAD mutations.Cell114635–645. 10.1016/j.cell.2003.08.008

  • 157

    MarquerC.LaineJ.DauphinotL.HanbouchL.Lemercier-NeuilletC.PierrotN.et al (2014). Increasing membrane cholesterol of neurons in culture recapitulates Alzheimer’s disease early phenotypes.Mol. Neurodegener.9:60. 10.1186/1750-1326-9-60

  • 158

    MartiniA.Gomez-ArboledasA.FornerS.Rodriguez-OrtizC.McQuadeA.DanhashE.et al (2019). Amyloid-beta impairs TOM1-mediated IL-1R1 signaling.Proc. Natl. Acad. Sci. U.S.A.11621198–21206. 10.1073/pnas.1914088116

  • 159

    MasoudG.LiW. (2015). HIF-1α pathway: Role, regulation and intervention for cancer therapy.Acta Pharm. Sin. B5378–389. 10.1016/j.apsb.2015.05.007

  • 160

    McElroyB.PowellJ.McCarthyJ. (2007). The insulin-like growth factor 1 (IGF-1) receptor is a substrate for gamma-secretase-mediated intramembrane proteolysis.Biochem. Biophys. Res. Commun.3581136–1141. 10.1016/j.bbrc.2007.05.062

  • 161

    MehraR.KeppK. (2021). Computational prediction and molecular mechanism of γ-secretase modulators.Eur. J. Pharm. Sci.157:105626. 10.1016/j.ejps.2020.105626

  • 162

    MekalaS.NelsonG.LiY. (2020). Recent developments of small molecule γ-secretase modulators for Alzheimer’s disease.RSC Med. Chem.111003–1022. 10.1039/d0md00196a

  • 163

    MerilahtiJ.OjalaV.KnittleA.PulliainenA.EleniusK. (2017). Genome-wide screen of gamma-secretase-mediated intramembrane cleavage of receptor tyrosine kinases.Mol. Biol. Cell283123–3131. 10.1091/mbc.E17-04-0261

  • 164

    MiK.JohnsonG. (2007). Regulated proteolytic processing of LRP6 results in release of its intracellular domain.J. Neurochem.101517–529. 10.1111/j.1471-4159.2007.04447.x

  • 165

    Miguel-ÁlvarezM.Santos-LozanoA.Sanchis-GomarF.Fiuza-LucesC.Pareja-GaleanoH.GaratacheaN.et al (2015). Non-steroidal anti-inflammatory drugs as a treatment for Alzheimer’s disease: A systematic review and meta-analysis of treatment effect.Drugs Aging32139–147. 10.1007/s40266-015-0239-z

  • 166

    MoniruzzamanM.IshiharaS.NobuharaM.HigashideH.FunamotoS. (2018). Glycosylation status of nicastrin influences catalytic activity and substrate preference of γ-secretase.Biochem. Biophys. Res. Commun.50298–103. 10.1016/j.bbrc.2018.05.126

  • 167

    MoraisV.CrystalA.PijakD.CarlinD.CostaJ.LeeV.et al (2003). The transmembrane domain region of nicastrin mediates direct interactions with APH-1 and the gamma-secretase complex.J. Biol. Chem.27843284–43291. 10.1074/jbc.M305685200

  • 168

    MoserC.Guschtschin-SchmidtN.SilberM.FlumJ.Muhle-GollC. (2024). Substrate selection criteria in regulated intramembrane proteolysis.ACS Chem. Neurosci.151321–1334. 10.1021/acschemneuro.4c00068

  • 169

    MoultonM.BarishS.RalhanI.ChangJ.GoodmanL.HarlandJ.et al (2021). Neuronal ROS-induced glial lipid droplet formation is altered by loss of Alzheimer’s disease-associated genes.Proc. Natl. Acad. Sci. U.S.A.118:e2112095118. 10.1073/pnas.2112095118

  • 170

    MukherjeeT.KimW.MandalL.BanerjeeU. (2011). Interaction between Notch and Hif-alpha in development and survival of Drosophila blood cells.Science3321210–1213. 10.1126/science.1199643

  • 171

    MurakamiK.WatanabeT.KoikeT.KamataM.IgariT.KondoS. (2016). Pharmacological properties of a novel and potent γ-secretase modulator as a therapeutic option for the treatment of Alzheimer’s disease.Brain Res.163373–86. 10.1016/j.brainres.2015.12.016

  • 172

    Nakano-ItoK.FujikawaY.HiharaT.ShinjoH.KotaniS.SuganumaA.et al (2014). E2012-induced cataract and its predictive biomarkers.Toxicol. Sci.137249–258. 10.1093/toxsci/kft224

  • 173

    NaumannE.GöringS.OgorekI.WeggenS.SchmidtB. (2013). Membrane anchoring γ-secretase modulators with terpene-derived moieties.Bioorg. Med. Chem. Lett.233852–3856. 10.1016/j.bmcl.2013.04.070

  • 174

    NetzerW.DouF.CaiD.VeachD.JeanS.LiY.et al (2003). Gleevec inhibits beta-amyloid production but not Notch cleavage.Proc. Natl. Acad. Sci. U.S.A.10012444–12449. 10.1073/pnas.1534745100

  • 175

    NiC.MurphyM.GoldeT.CarpenterG. (2001). gamma -Secretase cleavage and nuclear localization of ErbB-4 receptor tyrosine kinase.Science2942179–2181. 10.1126/science.1065412

  • 176

    NobutoK.KoheiA.HiroyukiH.ShigeoM.YasuoI. (2013). Suspected limited efficacy of γ-secretase modulators.Neurobiol. Aging341101–1104. 10.1016/j.neurobiolaging.2012.08.017

  • 177

    NordvallG.YanP.AgholmeL.LundkvistJ.SandinJ.BiverstålH.et al (2025). γ-secretase modulation inhibits amyloid plaque formation and growth and stimulates plaque regression in amyloid precursor protein/presenilin-1 mice.J. Pharmacol. Exp. Ther.392:103400. 10.1016/j.jpet.2025.103400

  • 178

    NyborgA.LaddT.ZwizinskiC.LahJ.GoldeT. (2006). Sortilin, SorCS1b, and SorLA Vps10p sorting receptors, are novel gamma-secretase substrates.Mol. Neurodegener.1:3. 10.1186/1750-1326-1-3

  • 179

    OikawaN.WalterJ. (2019). Presenilins and γ-secretase in membrane proteostasis.Cells8:209. 10.3390/cells8030209

  • 180

    Ong-PålssonE.NjavroJ.WilsonY.PigoniM.SchmidtA.MüllerS.et al (2022). The β-secretase substrate seizure 6-like protein (SEZ6L) controls motor functions in mice.Mol. Neurobiol.591183–1198. 10.1007/s12035-021-02660-y

  • 181

    OwenM.VriezeF.CrookR.WuW.HolmansP.FentonI.et al (2000). A full genome scan for late onset Alzheimers disease.Neurobiol. Aging21138–138. 10.1093/hmg/8.2.237

  • 182

    PanmonthaW.RerknimitrP.YeetongP.SrichomthongC.SuphapeetipornK.ShotelersukV. (2015). A frameshift mutation in PEN-2 causes familial comedones syndrome.Dermatology23177–81. 10.1159/000382122

  • 183

    Pardossi-PiquardR.BöhmC.ChenF.KanemotoS.CheclerF.Schmitt-UlmsG.et al (2009). TMP21 transmembrane domain regulates gamma-secretase cleavage.J. Biol. Chem.28428634–28641. 10.1074/jbc.M109.059345

  • 184

    PatelS.BansoadA.SinghR.KhatikG. (2022). BACE1: A key regulator in alzheimer’s disease progression and current development of its inhibitors.Curr. Neuropharmacol.201174–1193. 10.2174/1570159X19666211201094031

  • 185

    PengG.LiuY. (2015). Hypoxia-inducible factors in cancer stem cells and inflammation.Trends Pharmacol. Sci.36374–383. 10.1016/j.tips.2015.03.003

  • 186

    PetitD.HitzenbergerM.KochM.LismontS.ZoltowskaK.EnzleinT.et al (2022). Enzyme-substrate interface targeting by imidazole-based γ-secretase modulators activates γ-secretase and stabilizes its interaction with APP.EMBO J.41:e111084. 10.15252/embj.2022111084

  • 187

    PetterssonM.JohnsonD.HumphreyJ.ButlerT.Am EndeC.FishB.et al (2015). Design of pyridopyrazine-1,6-dione γ-secretase modulators that align potency, mdr efflux ratio, and metabolic stability.ACS Med. Chem. Lett.6596–601. 10.1021/acsmedchemlett.5b00070

  • 188

    PetterssonM.JohnsonD.RankicD.KauffmanG.Am EndeC.ButlerT.et al (2017). Discovery of cyclopropyl chromane-derived pyridopyrazine-1,6-dione γ-secretase modulators with robust central efficacy.Medchemcomm8730–743. 10.1039/c6md00406g

  • 189

    PigoniM.WanngrenJ.KuhnP.MunroK.GunnersenJ.TakeshimaH.et al (2016). Seizure protein 6 and its homolog seizure 6-like protein are physiological substrates of BACE1 in neurons.Mol. Neurodegener.11:67. 10.1186/s13024-016-0134-z

  • 190

    PinnerE.GruperY.Ben ZimraM.KristtD.LaudonM.NaorD.et al (2017). CD44 splice variants as potential players in Alzheimer’s disease pathology.J. Alzheimers Dis.581137–1149. 10.3233/JAD-161245

  • 191

    PlacanicaL.ChienJ.LiY. (2010). Characterization of an atypical gamma-secretase complex from hematopoietic origin.Biochemistry492796–2804. 10.1021/bi901388t

  • 192

    PleenJ.TownleyR. (2022). Alzheimer’s disease clinical trial update 2019-2021.J. Neurol.2691038–1051. 10.1007/s00415-021-10790-5

  • 193

    PrikhodkoO.RynearsonK.SekhonT.ManteM.NguyenP.RissmanR.et al (2020). The GSM BPN-15606 as a potential candidate for preventative therapy in Alzheimer’s disease.J. Alzheimers Dis.731541–1554. 10.3233/JAD-190442

  • 194

    ProkopS.ShirotaniK.EdbauerD.HaassC.SteinerH. (2004). Requirement of PEN-2 for stabilization of the presenilin N-/C-terminal fragment heterodimer within the gamma-secretase complex.J. Biol. Chem.27923255–23261. 10.1074/jbc.M401789200

  • 195

    RamnarayanV.HeinZ.JanßenL.LisN.GhanwatS.SpringerS. (2018). Cytomegalovirus gp40/m152 uses TMED10 as ER anchor to retain MHC class I.Cell Rep.233068–3077. 10.1016/j.celrep.2018.05.017

  • 196

    RatniH.AlkerA.BartelsB.BissantzC.ChenW.GerlachI.et al (2020). Discovery of RO7185876, a highly potent γ-secretase modulator (GSM) as a potential treatment for Alzheimer’s disease.ACS Med. Chem. Lett.111257–1268. 10.1021/acsmedchemlett.0c00109

  • 197

    RavenF.WardJ.ZoltowskaK.WanY.BylykbashiE.MillerS.et al (2017). Soluble gamma-secretase modulators attenuate Alzheimer’s β-amyloid pathology and induce conformational changes in presenilin 1.EBioMedicine2493–101. 10.1016/j.ebiom.2017.08.028

  • 198

    RivkinA.AhearnS.ChichettiS.HamblettC.GarciaY.MartinezM.et al (2010). Purine derivatives as potent gamma-secretase modulators.Bioorg. Med. Chem. Lett.202279–2282. 10.1016/j.bmcl.2010.02.008

  • 199

    Rodríguez SarmientoR.BissantzC.BylundJ.LimbergA.NeidhartW.Jakob-RoetneR.et al (2020). Stepwise design of γ-secretase modulators with an advanced profile by judicious coordinated structural replacements and an unconventional phenyl ring bioisostere.J. Med. Chem.638534–8553. 10.1021/acs.jmedchem.0c00909

  • 200

    RogaevE.SherringtonR.RogaevaE.LevesqueG.IkedaM.LiangY.et al (1995). Familial Alzheimer’s disease in kindreds with missense mutations in a gene on chromosome 1 related to the Alzheimer’s disease type 3 gene.Nature376775–778. 10.1038/376775a0

  • 201

    RoismanL.HanS.ChueiM.ConnorA.CappaiR. (2019). The crystal structure of amyloid precursor-like protein 2 E2 domain completes the amyloid precursor protein family.FASEB J.335076–5081. 10.1096/fj.201802315R

  • 202

    RynearsonK.BuckleR.BarnesK.HerrR.MayhewN.PaquetteW.et al (2016). Design and synthesis of aminothiazole modulators of the gamma-secretase enzyme.Bioorg. Med. Chem. Lett.263928–3937. 10.1016/j.bmcl.2016.07.011

  • 203

    RynearsonK.BuckleR.HerrR.MayhewN.ChenX.PaquetteW.et al (2020). Design and synthesis of novel methoxypyridine-derived gamma-secretase modulators.Bioorg. Med. Chem.28:115734. 10.1016/j.bmc.2020.115734

  • 204

    RynearsonK.PonnusamyM.PrikhodkoO.XieY.ZhangC.NguyenP.et al (2021). Preclinical validation of a potent γ-secretase modulator for Alzheimer’s disease prevention.J. Exp. Med.218:e20202560. 10.1084/jem.20202560

  • 205

    SannerudR.EsselensC.EjsmontP.MatteraR.RochinL.TharkeshwarA.et al (2016). Restricted location of PSEN2/γ-secretase determines substrate specificity and generates an intracellular aβ pool.Cell166193–208. 10.1016/j.cell.2016.05.020

  • 206

    SastreM.GentlemanS. (2010). NSAIDs: How they work and their prospects as therapeutics in Alzheimer’s disease.Front. Aging Neurosci.2:20. 10.3389/fnagi.2010.00020

  • 207

    SavaA. (2021). Design, synthesis and biological evaluation of novel anti-inflammatory agents / Conception, synt hèse et évaluation biologique de nouveaux agents anti-inflammatoires.Doctoral dissertation, Université d’Orléans and Universitatea de medicină şi farmacie “Grigore T. Popa”.Orléans.

  • 208

    SavasJ.RibeiroL.WierdaK.WrightR.DeNardo-WilkeL.RiceH.et al (2015). The sorting receptor SORCS1 regulates trafficking of neurexin and AMPA receptors.Neuron87764–780. 10.1016/j.neuron.2015.08.007

  • 209

    ScannevinR.ChollateS.BrennanM.Snodgrass-BeltP.PengH.XuL.et al (2016). BIIB042, a novel γ-secretase modulator, reduces amyloidogenic Aβ isoforms in primates and rodents and plaque pathology in a mouse model of Alzheimer’s disease.Neuropharmacology10357–68. 10.1016/j.neuropharm.2015.12.006

  • 210

    SchauenburgL.LiebschF.EravciM.MayerM.WeiseC.MulthaupG. (2018). APLP1 is endoproteolytically cleaved by γ-secretase without previous ectodomain shedding.Sci. Rep.8:1916. 10.1038/s41598-018-19530-8

  • 211

    SchellenbergG.BirdT.WijsmanE.OrrH.AndersonL.NemensE.et al (1992). Genetic linkage evidence for a familial Alzheimer’s disease locus on chromosome 14.Science258668–671. 10.1126/science.1411576

  • 212

    SchenkD.BasiG.PangalosM. (2012). Treatment strategies targeting amyloid β-protein.Cold Spring Harb. Perspect. Med.2:a006387. 10.1101/cshperspect.a006387

  • 213

    SekiokaR.HondaS.HonjoE.SuzukiT.AkashibaH.MitaniY.et al (2020b). Discovery of N-ethylpyridine-2-carboxamide derivatives as a novel scaffold for orally active γ-secretase modulators.Bioorg. Med. Chem.28:115132. 10.1016/j.bmc.2019.115132

  • 214

    SekiokaR.HondaS.AkashibaH.YarimizuJ.MitaniY.YamasakiS. (2020a). Optimization and biological evaluation of imidazopyridine derivatives as a novel scaffold for γ-secretase modulators with oral efficacy against cognitive deficits in Alzheimer’s disease model mice.Bioorg. Med. Chem.28:115455. 10.1016/j.bmc.2020.115455

  • 215

    SekiokaR.HonjoE.HondaS.FujiH.AkashibaH.MitaniY.et al (2018). Discovery of novel scaffolds for γ-secretase modulators without an arylimidazole moiety.Bioorg. Med. Chem.26435–442. 10.1016/j.bmc.2017.11.049

  • 216

    SelkoeD. (2001). Alzheimer’s disease: Genes, proteins, and therapy.Physiol. Rev.81741–766. 10.1152/physrev.2001.81.2.741

  • 217

    SelkoeD. (2013). The therapeutics of Alzheimer’s disease: Where we stand and where we are heading.Ann. Neurol.74328–336. 10.1002/ana.24001

  • 218

    ShahS.LeeS.TabuchiK.HaoY.YuC.LaPlantQ.et al (2005). Nicastrin functions as a gamma-secretase-substrate receptor.Cell122435–447. 10.1016/j.cell.2005.05.022

  • 219

    SherringtonR.RogaevE.LiangY.RogaevaE.LevesqueG.IkedaM.et al (1995). Cloning of a gene bearing missense mutations in early-onset familial Alzheimer’s disease.Nature375754–760. 10.1038/375754a0

  • 220

    ShiX. D.SunK.HuR.LiuX.HuQ.SunX.et al (2016). Blocking the interaction between EphB2 and ADDLs by a small peptide rescues impaired synaptic plasticity and memory deficits in a mouse model of Alzheimer’s disease.J. Neurosci.3611959–11973. 10.1523/JNEUROSCI.1327-16.2016

  • 221

    ShiJ.ZuevD.XuL.LentzK.GraceJ.ToynJ.et al (2016). Design and optimization of tricyclic gamma-secretase modulators.Bioorg. Med. Chem. Lett.261498–1502. 10.1016/j.bmcl.2015.06.020

  • 222

    ShiY.HoltzmanD. (2018). Interplay between innate immunity and Alzheimer disease: APOE and TREM2 in the spotlight.Nat. Rev. Immunol.18759–772. 10.1038/s41577-018-0051-1

  • 223

    SinghN.DasB.ZhouJ.HuX.YanR. (2022). Targeted BACE-1 inhibition in microglia enhances amyloid clearance and improved cognitive performance.Sci. Adv.8:eabo3610. 10.1126/sciadv.abo3610

  • 224

    SmallD.CappaiR. (2006). Alois Alzheimer and Alzheimer’s disease: A centennial perspective.J. Neurochem.99708–710. 10.1111/j.1471-4159.2006.04212.x

  • 225

    SmolarkiewiczM.SkrzypczakT.WojtaszekP. (2013). The very many faces of presenilins and the γ-secretase complex.Protoplasma250997–1011. 10.1007/s00709-013-0494-y

  • 226

    Soria LopezJ.GonzálezH.LégerG. (2019). Alzheimer’s disease.Handb. Clin. Neurol.167231–255. 10.1016/B978-0-12-804766-8.00013-3

  • 227

    SpasicD.ToliaA.DillenK.BaertV.De StrooperB.VrijensS.et al (2006). Presenilin-1 maintains a nine-transmembrane topology throughout the secretory pathway.J. Biol. Chem.28126569–26577. 10.1074/jbc.M600592200

  • 228

    SteinerH.WinklerE.HaassC. (2008). Chemical cross-linking provides a model of the gamma-secretase complex subunit architecture and evidence for close proximity of the C-terminal fragment of presenilin with APH-1.J. Biol. Chem.28334677–34686. 10.1074/jbc.M709067200

  • 229

    StropeT.WilkinsH. (2023). Amyloid precursor protein and mitochondria.Curr. Opin. Neurobiol.78:102651. 10.1016/j.conb.2022.102651

  • 230

    StützerI.SelevsekN.EsterházyD.SchmidtA.AebersoldR.StoffelM. (2013). Systematic proteomic analysis identifies β-site amyloid precursor protein cleaving enzyme 2 and 1 (BACE2 and BACE1) substrates in pancreatic β-cells.J. Biol. Chem.28810536–10547. 10.1074/jbc.M112.444703

  • 231

    SubramaniamS.KenneyD.JayaramanA.O’ConnellA.WalachowskiS.MontanaroP.et al (2024). Aging is associated with an insufficient early inflammatory response of lung endothelial cells in SARS-CoV-2 infection.Front. Immunol.15:1397990. 10.3389/fimmu.2024.1397990

  • 232

    SultanaR.BanksW.ButterfieldD. (2010). Decreased levels of PSD95 and two associated proteins and increased levels of BCl2 and caspase 3 in hippocampus from subjects with amnestic mild cognitive impairment: Insights into their potential roles for loss of synapses and memory, accumulation of Abeta, and neurodegeneration in a prodromal stage of Alzheimer’s disease.J. Neurosci. Res.88469–477. 10.1002/jnr.22227

  • 233

    SunC.JiaN.LiR.ZhangZ.ZhongY.HanK. (2020). miR-143-3p inhibition promotes neuronal survival in an Alzheimer’s disease cell model by targeting neuregulin-1.Folia Neuropathol.5810–21. 10.5114/fn.2020.94002

  • 234

    SunL.ZhaoL.YangG.YanC.ZhouR.ZhouX.et al (2015). Structural basis of human γ-secretase assembly.Proc. Natl. Acad. Sci. U.S.A.1126003–6008. 10.1073/pnas.1506242112

  • 235

    TakaiT.HoashiY.TomataY.MorimotoS.NakamuraM.WatanabeT.et al (2015). Discovery of novel 5,6,7,8-tetrahydro[1,2,4]triazolo[4,3-a]pyridine derivatives as γ-secretase modulators.Bioorg. Med. Chem. Lett.254245–4249. 10.1016/j.bmcl.2015.07.101

  • 236

    TakamiM.NagashimaY.SanoY.IshiharaS.Morishima-KawashimaM.FunamotoS.et al (2009). gamma-Secretase: Successive tripeptide and tetrapeptide release from the transmembrane domain of beta-carboxyl terminal fragment.J. Neurosci.2913042–13052. 10.1523/JNEUROSCI.2362-09.2009

  • 237

    TarassishinL.YinY.BassitB.LiY. (2004). Processing of Notch and amyloid precursor protein by gamma-secretase is spatially distinct.Proc. Natl. Acad. Sci. U.S.A.10117050–17055. 10.1073/pnas.0408007101

  • 238

    TejedaG.Ayuso-DoladoS.ArbetetaR.Esteban-OrtegaG.VidaurreO.Díaz-GuerraM. (2016). Brain ischaemia induces shedding of a BDNF-scavenger ectodomain from TrkB receptors by excitotoxicity activation of metalloproteinases and γ-secretases.J. Pathol.238627–640. 10.1002/path.4684

  • 239

    TeranishiY.HurJ.WelanderH.FrånbergJ.AokiM.WinbladB.et al (2010). Affinity pulldown of γ-secretase and associated proteins from human and rat brain.J. Cell Mol. Med.142675–2686. 10.1111/j.1582-4934.2009.00907.x

  • 240

    ThinakaranG.BorcheltD.LeeM.SluntH.SpitzerL.KimG.et al (1996). Endoproteolysis of presenilin 1 and accumulation of processed derivatives in vivo.Neuron17181–190. 10.1016/s0896-6273(00)80291-3

  • 241

    TrambauerJ.SarmientoR.GarringerH.SalbaumK.PedroL.CrusiusD.et al (2025). γ-Secretase modulator resistance of an aggressive Alzheimer-causing presenilin mutant can be overcome in the heterozygous patient state by a set of advanced compounds.Alzheimers Res. Ther.17:49. 10.1186/s13195-025-01680-3

  • 242

    UchidaY.GomiF.MurayamaS.TakahashiH. (2013). Calsyntenin-3 C-terminal fragment accumulates in dystrophic neurites surrounding aβ plaques in tg2576 mouse and Alzheimer disease brains: Its neurotoxic role in mediating dystrophic neurite formation.Am. J. Pathol.1821718–1726. 10.1016/j.ajpath.2013.01.014

  • 243

    UddinM.KabirM.JeandetP.MathewB.AshrafG.PerveenA.et al (2020). Novel anti-Alzheimer’s therapeutic molecules targeting amyloid precursor protein processing.Oxid. Med. Cell Longev.2020:7039138. 10.1155/2020/7039138

  • 244

    UlkuI.LeungR.HerreF.WaltherL.ShoboA.SaftigP.et al (2024). Inhibition of BACE1 affected both its Aβ producing and degrading activities and increased Aβ42 and Aβ40 levels at high-level BACE1 expression.J. Biol. Chem.300:107510. 10.1016/j.jbc.2024.107510

  • 245

    VassarR. (2012). BACE1, the Alzheimer’s beta-secretase enzyme, in health and disease.Mol. Neurodegener.7:L3. 10.1186/1750-1326-2-22

  • 246

    VetrivelK.ChengH.LinW.SakuraiT.LiT.NukinaN.et al (2004). Association of gamma-secretase with lipid rafts in post-Golgi and endosome membranes.J. Biol. Chem.27944945–44954. 10.1074/jbc.M407986200

  • 247

    VetrivelK.GongP.BowenJ.ChengH.ChenY.CarterM.et al (2007). Dual roles of the transmembrane protein p23/TMP21 in the modulation of amyloid precursor protein metabolism.Mol. Neurodegener.2:4. 10.1186/1750-1326-2-4

  • 248

    VetrivelK.KodamA.GongP.ChenY.ParentA.KarS.et al (2008). Localization and regional distribution of p23/TMP21 in the brain.Neurobiol. Dis.3237–49. 10.1016/j.nbd.2008.06.012

  • 249

    VillaJ.ChiuD.BrandesA.EscorciaF.VillaC.MaguireW.et al (2014). Nontranscriptional role of Hif-1α in activation of γ-secretase and notch signaling in breast cancer.Cell Rep.81077–1092. 10.1016/j.celrep.2014.07.028

  • 250

    WagnerS.RynearsonK.DuddyS.ZhangC.NguyenP.BeckerA.et al (2017). Pharmacological and toxicological properties of the potent oral γ-secretase modulator BPN-15606.J. Pharmacol. Exp. Ther.36231–44. 10.1124/jpet.117.240861

  • 251

    WahrleS.DasP.NyborgA.McLendonC.ShojiM.KawarabayashiT.et al (2002). Cholesterol-dependent gamma-secretase activity in buoyant cholesterol-rich membrane microdomains.Neurobiol. Dis.911–23. 10.1006/nbdi.2001.0470

  • 252

    WalkerD.TangT.LueL. (2017). Studies on colony stimulating factor receptor-1 and ligands colony stimulating factor-1 and interleukin-34 in Alzheimer’s disease brains and human microglia.Front. Aging Neurosci.9:244. 10.3389/fnagi.2017.00244

  • 253

    WalterJ.SchindzielorzA.GrünbergJ.HaassC. (1999). Phosphorylation of presenilin-2 regulates its cleavage by caspases and retards progression of apoptosis.Proc. Natl. Acad. Sci. U.S.A.961391–1396. 10.1073/pnas.96.4.1391

  • 254

    WangR.SweeneyD.GandyS.SisodiaS. (1996). The profile of soluble amyloid beta protein in cultured cell media. Detection and quantification of amyloid beta protein and variants by immunoprecipitation-mass spectrometry.J. Biol. Chem.27131894–31902. 10.1074/jbc.271.50.31894

  • 255

    WangR.ZhangY.ZhangX.LiuR.ZhangX.HongS.et al (2006). Transcriptional regulation of APH-1A and increased gamma-secretase cleavage of APP and Notch by HIF-1 and hypoxia.FASEB J.201275–1277. 10.1096/fj.06-5839fje

  • 256

    WangY.LiuY.MalekS.ZhengP.LiuY. (2011). Targeting HIF1α eliminates cancer stem cells in hematological malignancies.Cell Stem Cell8399–411. 10.1016/j.stem.2011.02.006

  • 257

    WatanabeN.TomitaT.SatoC.KitamuraT.MorohashiY.IwatsuboT. (2006). Pen-2 is incorporated into the gamma-secretase complex through binding to transmembrane domain 4 of presenilin 1.J. Biol. Chem.28041967–41975. 10.1074/jbc.M509066200

  • 258

    WeggenS.EriksenJ.DasP.SagiS.WangR.PietrzikC.et al (2001). A subset of NSAIDs lower amyloidogenic Abeta42 independently of cyclooxygenase activity.Nature414212–216. 10.1038/35102591

  • 259

    WeiY.MaM.LinS.LiX.ShuY.WangZ.et al (2021). Proteolytic shedding of human colony-stimulating factor 1 receptor and its implication.J. Cell Mol. Med.254516–4521. 10.1111/jcmm.16474

  • 260

    WolfeM. (2012). γ-Secretase inhibitors and modulators for Alzheimer’s disease.J. Neurochem.12089–98. 10.1111/j.1471-4159.2011.07501.x

  • 261

    WolfeM. (2019). Structure and function of the γ-secretase complex.Biochemistry582953–2966. 10.1021/acs.biochem.9b00401

  • 262

    WolfeM. (2024). γ-Secretase: Once and future drug target for Alzheimer’s disease.Expert Opin. Drug Discov.195–8. 10.1080/17460441.2023.2277350

  • 263

    WongE.FrostG.LiY. (2020). γ-secretase modulatory proteins: The guiding hand behind the running scissors.Front. Aging Neurosci.12:614690. 10.3389/fnagi.2020.614690

  • 264

    WongE.LiaoG.ChangJ.XuP.LiY.GreengardP. (2019). GSAP modulates γ-secretase specificity by inducing conformational change in PS1.Proc. Natl. Acad. Sci. U.S.A.1166385–6390. 10.1073/pnas.1820160116

  • 265

    WongG.ManfraD.PouletF.ZhangQ.JosienH.BaraT.et al (2004). Chronic treatment with the gamma-secretase inhibitor LY-411,575 inhibits beta-amyloid peptide production and alters lymphopoiesis and intestinal cell differentiation.J. Biol. Chem.27912876–12882. 10.1074/jbc.M311652200

  • 266

    WuY.ZhangY.ToynJ.MacorJ.ThompsonL. (2016). Synthesis of pyrimido[4,5-c]azepine- and pyrimido[4,5-c]oxepine-based γ-secretase modulators.Bioorg. Med. Chem. Lett.261554–1557. 10.1016/j.bmcl.2016.02.016

  • 267

    WunderlichP.GlebovK.KemmerlingN.TienN.NeumannH.WalterJ. (2013). Sequential proteolytic processing of the triggering receptor expressed on myeloid cells-2 (TREM2) protein by ectodomain shedding and γ-secretase-dependent intramembranous cleavage.J Biol Chem.28833027–33036. 10.1074/jbc.M113.517540

  • 268

    XuJ.LitterstC.GeorgakopoulosA.ZaganasI.RobakisN. (2009). Peptide EphB2/CTF2 generated by the gamma-secretase processing of EphB2 receptor promotes tyrosine phosphorylation and cell surface localization of N-methyl-D-aspartate receptors.J. Biol. Chem.28427220–27228. 10.1074/jbc.M109.048728

  • 269

    XuM.LiuQ.BiR.LiY.LiH.KangW.et al (2023). Coexistence of multiple functional variants and genes underlies genetic risk locus 11p11.2 of Alzheimer’s disease.Biol. Psychiatry94743–759. 10.1016/j.biopsych.2023.05.020

  • 270

    XuP.ChangJ.ZhouX.WangW.BamkoleM.WongE.et al (2021). GSAP regulates lipid homeostasis and mitochondrial function associated with Alzheimer’s disease.J. Exp. Med.218:e20202446. 10.1084/jem.20202446

  • 271

    XuT.YanY.KangY.JiangY.MelcherK.XuH. (2016). Alzheimer’s disease-associated mutations increase amyloid precursor protein resistance to γ-secretase cleavage and the Aβ42/Aβ40 ratio.Cell Discov.2:16026. 10.1038/celldisc.2016.26

  • 272

    YánezD.RossS.CromptonT. (2020). The IFITM protein family in adaptive immunity.Immunology159365–372. 10.1111/imm.13163

  • 273

    YangG.ZhouR.GuoX.YanC.LeiJ.ShiY. (2021). Structural basis of γ-secretase inhibition and modulation by small molecule drugs.Cell184:521–533.e14. 10.1016/j.cell.2020.11.049

  • 274

    YangG.ZhouR.ZhouQ.GuoX.YanC.KeM.et al (2019). Structural basis of Notch recognition by human γ-secretase.Nature565192–197. 10.1038/s41586-018-0813-8

  • 275

    YaoA.YanR. (2020). Activity of Alzheimer’s γ-secretase is linked to changes of interferon-induced transmembrane proteins (IFITM) in innate immunity.Mol. Neurodegener.15:69. 10.1186/s13024-020-00417-0

  • 276

    YinH.WangY.RenZ.XiaoZ.ZhangY.WangY.et al (2025). TDP43 is a newly identified substrate for PS1, enhancing the expression of APP following cleavage.Cell Death Discov.11:76. 10.1038/s41420-025-02340-z

  • 277

    YongY.ZhangR.LiuZ.WeiD.ShangY.WuJ.et al (2019). Gamma-secretase complex-dependent intramembrane proteolysis of CD147 regulates the Notch1 signaling pathway in hepatocellular carcinoma.J. Pathol.249255–267. 10.1002/path.5316

  • 278

    YuG.ChenF.LevesqueG.NishimuraM.ZhangD.LevesqueL.et al (1998). The presenilin 1 protein is a component of a high molecular weight intracellular complex that contains beta-catenin.J. Biol. Chem.27316470–16475. 10.1074/jbc.273.26.16470

  • 279

    YuG.NishimuraM.ArawakaS.LevitanD.ZhangL.TandonA.et al (2000). Nicastrin modulates presenilin-mediated notch/glp-1 signal transduction and betaAPP processing.Nature40748–54. 10.1038/35024009

  • 280

    YuY.LogovinskyV.SchuckE.KaplowJ.ChangM.MiyagawaT.et al (2014). Safety, tolerability, pharmacokinetics, and pharmacodynamics of the novel γ-secretase modulator, E2212, in healthy human subjects.J. Clin. Pharmacol.54528–536. 10.1002/jcph.249

  • 281

    ZengL.LiT.XuD.LiuJ.MaoG.CuiM.et al (2012). Death receptor 6 induces apoptosis not through type I or type II pathways, but via a unique mitochondria-dependent pathway by interacting with Bax protein.J. Biol. Chem.28729125–29133. 10.1074/jbc.M112.362038

  • 282

    ZhangH.MaQ.ZhangY.XuH. (2012). Proteolytic processing of Alzheimer’s β-amyloid precursor protein.J. Neurochem.1209–21. 10.1111/j.1471-4159.2011.07519.x

  • 283

    ZhangX.LiY.XuH.ZhangY. (2014). The γ-secretase complex: From structure to function.Front. Cell. Neurosci.8:427. 10.3389/fncel.2014.00427

  • 284

    ZhangX.WuY.CaiF.SongW. (2019). Regulation of global gene expression in brain by TMP21.Mol. Brain12:39. 10.1186/s13041-019-0460-5

  • 285

    ZhangX.YuC.SisodiaS. (2015). The topology of pen-2, a γ-secretase subunit, revisited: Evidence for a reentrant loop and a single pass transmembrane domain.Mol. Neurodegener.10:39. 10.1186/s13024-015-0037-4

  • 286

    ZhaoZ.PissarnitskiD.HuangX.PalaniA.ZhuZ.GreenleeW.et al (2017). Discovery of a tetrahydrobenzisoxazole series of γ-secretase modulators.ACS Med. Chem. Lett.81002–1006. 10.1021/acsmedchemlett.7b00178

  • 287

    ZhengQ.WangX. (2025). Alzheimer’s disease: Insights into pathology, molecular mechanisms, and therapy.Protein Cell1683–120. 10.1093/procel/pwae026

  • 288

    ZhouS.ZhouH.WalianP.JapB. (2005). CD147 is a regulatory subunit of the gamma-secretase complex in Alzheimer’s disease amyloid beta-peptide production.Proc. Natl. Acad. Sci. U.S.A.1027499–7504. 10.1073/pnas.0502768102

  • 289

    ZhuoX.HowellB.ShenH.WoodheadJ.MosureK.ZhangY.et al (2023). Mechanistic investigation of liver injury induced by BMS-932481, an experimental γ-secretase modulator.Toxicol. Sci.194235–245. 10.1093/toxsci/kfad057

  • 290

    ZouZ.ChungB.NguyenT.MentoneS.ThomsonB.BiemesderferD. (2004). Linking receptor-mediated endocytosis and cell signaling: Evidence for regulated intramembrane proteolysis of megalin in proximal tubule.J. Biol. Chem.27934302–34310. 10.1074/jbc.M405608200

  • 291

    ZubenkoG.HughesH.StifflerJ.HurttM.KaplanB. B. (1998). A genome survey for novel Alzheimer disease risk loci: Results at 10-cM resolution.Genomics50121–128. 10.1006/geno.1998.5306

  • 292

    ZurhoveK.NakajimaC.HerzJ.BockH.MayP. (2008). Gamma-secretase limits the inflammatory response through the processing of LRP1.Sci. Signal.1:ra15. 10.1126/scisignal.1164263

Summary

Keywords

γ-secretase, Alzheimer’s disease, GSMS, GSMPs, type I transmembrane proteins

Citation

Ning G, Fan X, Juan D, wenxue Z, Sijia W, Meinei C, Xiaolong D and Yiming Q (2025) The manipulator behind “Scissors”: γ -secretase and its modulators in Alzheimer’s disease. Front. Aging Neurosci. 17:1637671. doi: 10.3389/fnagi.2025.1637671

Received

29 May 2025

Accepted

08 August 2025

Published

25 August 2025

Volume

17 - 2025

Edited by

Ilya Bezprozvanny, Peter the Great St.Petersburg Polytechnic University, Russia

Reviewed by

Saleha Anwar, Jamia Hamdard University, India

Yuan Xu, Changzhou First People’s Hospital, China

Updates

Copyright

*Correspondence: Gao Ning,

†These authors have contributed equally to this work

Disclaimer

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.

Outline

Figures

Cite article

Copy to clipboard


Export citation file


Share article

Article metrics