Editorial: The Role of Autophagy in Cardiovascular Disease Critical role of autophagy in cardiac physiology and pathology, and the possible involvement of cellular macrostructure-tunneling nanotube (TNT) in early cardiac embryogenesis

Qinchun Duan¹Xuehong Xu^1*Odell D. Jones²Jianjie Ma³Joseph Bryant⁴MengMeng Xu^5*

• ¹College of Life Sciences, Shaanxi Normal University, Xi’an, China
• ²University of Pennsylvania, Philadelphia, United States
• ³University of Virginia Biocomplexity Institute, Charlottesville, United States
• ⁴University of Maryland Medical Center, Baltimore, United States
• ⁵Columbia University, New York, United States

1. Autophagy — an evolutionary conserved function linking cardiac development to cardiac pathogenesis, from Drosophila to humans Autophagy is a highly conserved catabolic process that plays a critical role in maintaining cellular quality control across species. During cardiac organogenesis, autophagy is essential for preserving cardiac homeostasis by eliminating dysfunctional organelles, misfolded proteins, and damaged macromolecules. Genetic manipulation in Drosophila has provided a foundational understanding for the importance of autophagy in cardiac development. Studies in human aging and pathogenic process has also linked this vital cellular process to stress, aging, and metabolic challenges to offer a unifying molecular and cellular framework underlying cardiac pathogenesis. 1.1 Insights from Drosophila melanogaster: The genetic foundation of cardiac autophagy Drosophila have yielded significant cellular and molecular mechanistic insights into the cardioprotective functions of autophagy. In Drosophila, autophagy-related cardiac dysfunction has been closely associated with dysregulation of the mTOR/ULK1 signaling axis. Notably, pharmacological inhibition of mTORC1 reactivates ULK1 to enhance autophagic flux, and ameliorate cardiomyopathic phenotypes observed in Lamin C (LamC) mutants (Demir et al., 2023; Hegedűs et al., 2016; Zhang et al., 2025). These LamC mutants display compromised nuclear envelope integrity and disrupted nuclear–cytoplasmic communication, resulting in proteotoxicity and oxidative stress—classic features of impaired autophagy (Bhide et al., 2018; Chandran et al., 2019; Kirkland et al., 2023; Walker et al., 2023). Mutations affecting nuclear envelope components, such as LamC, interfere with the mTORC1–ULK1 axis, suppressing autophagic activity and leading to cardiac dysfunction. Treatment with rapamycin, an mTORC1 inhibitor, effectively restores autophagic flux and improves cardiac outcomes, underscoring the conserved role of mTOR signaling in cardiac homeostasis. Crucial core autophagy-related genes Atg1, Atg5, and Atg8 are indispensable for autophagosome formation and normal cardiac function. Upstream metabolic regulators of these genes through the AMPK and the PI3K/Akt pathway modulate mTORC1 activity to influence autophagic flux, linking energy sensing and growth signaling for cardiac maintenance and remodeling (Kirkland et al., 2023; Walker et al., 2023; Pai et al., 2023). These regulatory interactions form part of a broader metabolic network essential for adapting the postnatal heart to physiologic stress. Disturbances in this pathway leads to early postnatal death. Collectively, findings from Drosophila provide a robust genetic and biochemical foundation for understanding evolutionarily conserved autophagy mechanisms contributing to cardiomyocyte resilience in human cardiac disease. This cross-species paradigm reinforces the translational relevance of autophagy as a therapeutic target for mitigating cardiac disease arising from genetic mutations or environmental insults. 1.2 Autophagy in viral and inflammatory cardiomyopathy: HIV as a model of immune-metabolic disruption The pathogenesis of HIV-associated cardiomyopathy (HACM) underscores the detrimental consequences of impaired autophagy in the adult human heart. HIV infection affects chaperone-mediated autophagy (CMA) to cause cardiomyopathy in infected patients (collected in this issue, Sun et al., 2024). Dysregulation of CMA— critical for maintaining cardiomyocyte and macrophage mitochondrial integrity and immune homeostasis—leads to the accumulation of reactive oxygen species (ROS), activation of the inflammasome, and induction of pyroptosis (Gatica et al., 2022; Avula et al., 2021; Bulló et al., 2021; Morales et al., 2020; Abdel-Rahman et al., 2021; Ning et al., 2023; Li et al., 2022). In HIV infection and exposure to highly active antiretroviral therapy (HAART), mTOR signaling becomes hyperactivated, thereby downregulating ULK1 (unc-51 like autophagy activating kinase 1), a gene essential to autophagosome biogenesis. Suppression of ULK1 leads to reduced autophagy and further compromising cardiomyocyte survival in the setting of viral or drug injury (Sun, et al., 2024; Akbay et al., 2020; Crater et al., 2022; Singh et al., 2022). Pharmacological inhibition of mTORC1 can restore ULK1 activity and reinstate mitochondrial quality control, highlighting a promising therapeutic axis in autophagy-based cardiac interventions. HIV-associated clonal hematopoiesis (CH)—propelled by somatic mutations in Tet2, Dnmt3a, and Jak2— further exacerbates inflammatory responses through impaired mitophagy and dysregulated macrophage signaling (Dharan et al., 2021; Bick et al., 2022; Wang et al., 2022). The pathological relevance of autophagic disruption in immune-mediated myocardial damage is reinforced by the observation that autophagy inhibition aggravates cardiac inflammation and slows adaptive remodeling. These mutations replicate the dysfunctional immune-metabolic axis previously observed in autophagy-deficient Drosophila models. Thus providing a mechanistic bridge linking immune dysregulation to cardiac injury in human disease. This evolutionary parallel accentuates the conserved role of autophagy in modulating inflammatory and metabolic homeostasis across species. 1.3 Autophagy in metabolic stress and cardiac remodeling: Maintaining homeostasis in metabolic stress In models of obesity and diabetes, such as high-fat diet (HFD) combined with streptozotocin (STZ)- induced metabolic cardiomyopathy (MCM), autophagic activity is markedly suppressed due to insulin resistance-mediated hyperactivation of the mTORC1 signaling pathway (collected in this issue, Zhou et al., 2025). This suppression compromises the clearance of dysfunctional mitochondria and promotes lipid overload and oxidative stress—key pathological features characteristic of diabetic heart disease. Autophagy is a critical adaptive response in HFD/STZ-induced models of MCM that counteracts metabolic stress through multiple regulatory mechanisms. Specifically, autophagy alleviates lipid accumulation, fibrosis, and mitochondrial dysfunction by engaging the AMPK/mTOR/ULK1 and PINK1/Parkin-dependent signaling pathways (Madonna et al., 2023; Wang et al., 2017; Lin et al., 2021; Zhang et al., 2022; Elrashidy et al., 2021). Selective autophagy processes—including mitophagy (via PINK1/Parkin), lipophagy, and ferritinophagy—play central roles in maintaining mitochondrial integrity, regulating lipid metabolism, and controlling intracellular iron levels. Disruption of these pathways results in lipotoxicity, ferroptosis, and impaired energy metabolism (Li et al., 2025). Both selective and non-selective autophagy work in concert to sustain myocardial homeostasis by clearing cytotoxic byproducts and preserving organelle function. Transcriptional regulators such as FOXO3, BNIP3, and TFEB, along with autophagy-related microRNAs like miR-34a, coordinate the expression of autophagy and lysosome-associated genes (Wang et al., 2021). Genetically engineered disruptions along the AMPK/mTOR/ULK1 and PINK1/Parkin-dependent signaling pathways in Drosophila induces the same autophagy failure and metabolic derangements described in human pathology (Zhang et al., 2025). These findings indicate that these tightly regulated autophagy signaling networks are evolutionarily critical cross species, and that precise modulation of autophagic flux is crucial in the prevention and management of metabolic heart failure. 1.4 Macrophage autophagy, clonal hematopoiesis, and inflammatory atherosclerosis: Immune crosstalk in human cardiovascular disease Macrophage autophagy—particularly CMA—plays a pivotal role in regulating lipid metabolism, controlling inflammation, and maintaining mitochondrial function (Li et al., 2025; Duan et al., 2023). Dysfunctional CMA contributes to the formation of foam cells, increased ROS accumulation, and activation of the NLRP3 inflammasome, thereby promoting pyroptotic cell death (Nussenzweig et al., 2015; Zhang et al., 2022; Díez-Díez et al., 2024; Yunna et al., 2020; Duewell et al., 2010). Deficient CMA impairs cholesterol efflux and facilitates the buildup of lipid droplets by hindering ABCA1-mediated cholesterol transport. This results in degraded lipid droplet-coating proteins such as PLIN2, which reinforces a cycle of vascular lipid overload and inflammation central to development of atherosclerosis. Clonal hematopoiesis-associated mutations in genes such as Tet2, Jaks, and Dnmt3a have been shown to suppress mitophagy and shift macrophage cytokine profiles toward pro-inflammatory phenotypes (Jaiswal et al., 2017; Fuster et al., 2017; Zhao et al., 2020; Abplanalp et al., 2021). These mutations commonly accumulate in macrophages with age, illustrating how somatic changes in hematopoietic stem cells may affect macrophage function in an age related fashion. This progressive impairment of macrophage autophagic regulation promotes chronic vascular inflammation and senescence-associated atherosclerotic progression to accelerate atherogenesis with age. Importantly, restoration of CMA activity in macrophages—either through LAMP2A overexpression or pharmacological activation—has been shown to attenuate vascular inflammation and enhance plaque stability (Valdor et al., 2024; Fernández et al., 2017). 1.5. Cardiovascular aging and autophagy modulation via non-coding RNAs: Senescence as a new frontier Aging is the cumulative breakdown of cellular homeostasis. This is true in cardiovascular tissues where impaired autophagy exacerbates mitochondrial dysfunction, oxidative stress, and proteotoxicity over time. Non-coding RNAs (ncRNAs), including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), has recently been shown to regulate autophagy by modulating key signaling pathways, such as the previously discussed AMPK/mTOR and ULK1 pathways. Dysregulation of these ncRNAs contributes significantly to age-related cardiovascular decline (collected in this issue, Silvia et al., 2025). Recent studies reveal that specific ncRNAs can enhance autophagic capacity and reduce markers of cellular senescence in endothelial cells and cardiomyocytes (Yang et al., 2017; Liang et al., 2020; Zhang et al., 2025). From a therapeutic perspective, targeting ncRNAs to restore or optimize autophagic activity presents a promising strategy to delay cardiovascular aging and promote healthy lifespan extension. 2. Autophagy and tunneling nanotube (TNT) mediated heart development Traditionally, the primitive mammalian heart is thought to originate from cardiac-specific progenitor cells which subsequently differentiate into endocardial and myocardial precursors. However, a recent 2025 investigation challenged this notion. This study demonstrated the primitive heart to arise directly from endocardial and myocardial precursors rather than from cardiac-specific progenitors [Sendra et al., 2025]. A new key cellular macrostructure fundamental to mammalian cardiac development —tunneling nanotube-like structures (TNTLs)— recently identified in mouse embryonic hearts might be the structural mechanism linking these two findings [Miao et al., 2025, de la Pompa, J.L., 2025]. Tunneling nanotubes (TNTs) are well-known intercellular communication structures Polak et al., 2015; Rustom et al., 2004; Sowinski et al., 2008; Wang et al., 2015; Rainy et al., 2013; Lou et al., 2012] critical to many cellular processes. Their identification within cardiac development revealed a new context for these microstructures [Goodman et al., 2019; Hulsmans et al., 2017; Zhou et al., 2018; Li et al., 2025; Wang et al., 2010; Ariazi et al., 2017]. The existence of TNTLs in the setting of dual cell type cardiac origin may explain how autophagy, a known process through which neighboring cells communicate may be involved in cardiac embryogenesis. In fact, TNT have already been shown to be involved in macrophage autophagy mediated electrical commutation between mature cardiomyocytes [Rustom et al., 2004; de Rooij et al., 2017; Morrison et al., 2014; Polak et al., 2015; Barutta et al., 2023; Ottonelli et al., 2022; Venkatesh et al., 2019]. Figure 1. Function tunneling nanotube (TNT) in cellular communication during cardiac development. 2.1 The primitive heart does not arise from cardiac-specific progenitors but from endocardial and myocardial precursors Recent studies have called into question the previously accepted perspective that embryonic hearts develop from cells originating from cardiac-specific progenitors. Using unbiased cell lineage tracing and live imaging techniques, Sendra et al. demonstrated that primitive heart originates not from cardiac-specific progenitors but rather from a coordinated interaction between endocardial and myocardial precursors. These two primary cell lineages migrate and ultimately form the heart during the gastrulation stage of early embryogenesis [Sendra et al., 2025]. In their experiments, these two multipotent mesodermal populations independently give rise to future cardiomyocytes, and future endocardial cells through synchronized ingression into the primitive streak. Furthermore, these lineages contribute to the development of additional tissues necessary for successful gastrulation. Intriguingly, TNTLs may be vital in mediating dual cell lineage coordination [Xu et al., 2017;Xu et al., 2017; Miao et al., 2025; de la Pompa, J.L., 2025, Huynh, 2025], potentially establishing link between embryonic autophagy and cardiac development [Aktaş et al., 2025; de Rooij et al., 2017]. 2.2 TNTLs in mouse embryonic hearts A recent study identified a distinct cellular structure termed tunneling nanotube-like structures (TNTLs) within mouse embryonic hearts. The authors proposed that these TNTLs within the cardiac jelly serve as physical linkages between the endocardium and myocardium to facilitate signaling interactions through protein exchange between endocardial cells and cardiomyocytes [Huynh, 2025; Miao et al., 2025; de la Pompa, J.L., 2025]. Using an in vitro co-culture system combined with fluorescently labeled cytoskeletal polymerization assays, their data demonstrated that the formation of TNTLs in vivo depends on cytoskeleton actin filaments rather than microtubules [Miao et al., 2025; de la Pompa, J.L., 2025]. Employing various genetically modified mouse strains—including Cdc42^fl/fl, mTmG, tdTomato, CBF1:H2b-Venus, CD9-eGFP, and Jag1-eGFP BAC transgenic mice—the study further revealed that the GTPase CDC42 is essential for TNTL formation by regulating actin cytoskeletal dynamics. CDC42 is a critical component of the NOTCH1 signaling pathway, which is essential for embryonic heart progenitor differentiation and growth. Mutations in NOTCH1 are known to cause congenital cardiac disease. The findings suggest that CDC42-mediated TNTL formation modulates NOTCH1 activation and potentially influences JAG1/2 signaling as well [Miao et al., 2025]. This discovery addresses a longstanding gap between now endocardium-myocardiumcell microstructural interactions and spatial connectivity affect ardaic structural formation, such as cardiac trabeculation and ventricular wall formation. It is well established that autophagy plays a vital role in animal development and organogenesis; for example, Beclin-1 deletion results in embryonic lethality in mice, underscoring its critical function in embryogenesis [Yue et al., 2003]. At present, two pivotal questions merit further investigation: (1) whether tunneling nanotube-like structures represent a common cellular phenomenon across various cellular processes both in vitro and in vivo, and (2) whether there is a mechanistic link between these structures and cellular autophagy. 2.3 TNT as a common cellular communication structure critical within embryogenesis Membrane nanotubes (TNTs) were discovered during development of Drosophila melanogaster wing imaginal discs [Ramírez-Weber et al., 1999]. Later, TNTs were observed in vivo and in vitro systems to connect PC12 cells with other cells [Rustom et al., 2004; Onfelt et al., 2004]. TNTs were initially recognized as conduits facilitating intercellular organelle transport between interacting cells [Rustom et al., 2004]. These membrane-bound nanotubes, first identified in T cells, were shown to physically connect cells and potentially serve as novel pathways for HIV transmission [Sowinski et al., 2008]. However, the cellular and molecular mechanisms underlying these structures remained unclear. Subsequent studies revealed that TNTs provide unique channels not only for organelle transfer but also for broader intercellular content exchange, as demonstrated in malignant human pleural mesothelioma cells derived [Lou et al., 2012]. In 2015, Polak et al. showed that TNTs originating from B-cell acute lymphoblastic leukemia cells (B-ALL) contribute to the regulation and organization of the leukemic microenvironment [Polak et al., 2015]. Additionally, Rainy et al. reported that H-Ras protein transfer from B to T cells via TNTs [Rainy et al., 2013]. Further research has uncovered that even large structures like mitochondrial can also be transfer through TNTs. Mitochondria have been shown to transfer between cells in and reverse apoptosis in ultraviolet (UV)-damaged pheochromocytoma PC12 cells to rescue injured cells from cell death in co-culture systems [Wang et al., 2015]. Recent studies have also demonstrated that TNT formation and its role in intercellular organelle trafficking is modulated by macrophage polarization in many different pathology cell types including NRK cell, neural crest cells, HEK293, HUVEC, NCC, PC12, Neuron-astrocytes, and ARPE [[Goodman et al., 2019; Rustom et al., 2004; Wang, X., et al 2010]. Circulating macrophages perform critical functions across various tissues by interacting directly with resident cells. TNTs provide the cytosol-to-cytosol connections required for direct cell-to-cell communication. Studies involving hematopoietic stem and progenitor cell (HSPC) transplantation have demonstrated that HSPC-derived macrophages can form TNTs to transport cystinosin-bearing lysosomes directly to recipient cystinotic cells. This allows circulating macrophages to preserve tissue through a TNT deliveredm autophagy driven mechanism [Goodman et al., 2019; Naphade et al., 2015]. In 2019, Goodman et al. observed through co-culture experiments of macrophages with cystinotic cells, that macrophage polarization induces membrane protrusions resembling TNTs. These TNT like protrusion in turn facilitate the transfer of both lysosomal and mitochondrial contents from macrophages to cystinotic cells [Goodman et al., 2019]. Macrophages have also been shown to play indispensable roles in cardiac function. Genetic modification and localization of circulating macrophages has been shown to modulate electrical signaling within the heart [Hulsmans et al., 2017; Zhou et al., 2018; Li et al., 2025]. TNT has been shown to modulate electrical signal transmission in multiple animal cell types, including HEK293, HUVEC, NCC, and PC12 cells. TNT-dependent electrical coupling is linked to connexin 43 (Cx43)- associated functional gap junctions and correlates with low voltage-gated Ca2+ channel activity in recipient HEK293 cells [Wang et al., 2010; Ariazi et al., 2017] (Table 1). TNTs and similarly characterized cellular structures appear to be ubiquitous at the cell and tissue levels. Similar vascular-like networks have also been identified in stem cell differentiation systems [Xu et al., 2017]. In 2017, Xu et al. described a network composed of liquid crystal tunneling tubules within the embryoid body derived from human H2 stem cell lines. This TNT network initiates at the surface of the embryoid body, traverses the cortical region, and extends into the central zone [Xu et al., 2017]. TNT openings on the embryoid body's surface were evenly distributed, while in the central zone, the tubules terminate in characteristic "water-drop" shapes. This system efficiently connects the embryoid body to its microenvironment suggesting the presence of a liquid crystal TNT (LC-TNT) system in early embryonic development. 2.4 TNT mediated autophagy is critical for heart development The actin cytoskeleton TNTs appear to function as non-selective cellular conduits that mediate the exchange of cytosolic components across diverse cell types [Rustom et al., 2004]. Recent studies have established a significant link between TNT-mediated intercellular communication and autophagy, hinting at a protective role through the transfer of autophagosomes to neighboring cells within leukemic niches and diabetic podocytes [[de Rooij et al., 2017; Barutta et al., 2023]. Building on these findings, the Boer group demonstrated that TNT-mediated interactions between leukemic cells and bone marrow-derived mesenchymal stromal cells (MSCs) are critical for acute lymphoblastic leukemia progression [Morrison et al., 2014; Polak et al., 2015]. Specifically, autophagosomes, mitochondria, and the transmembrane protein ICAM1 were observed to be transferred from B-cell precursor cells to MSCs, alongside the exchange of lipophilic molecules via TNTs de Rooij et al., 2017; Polak et al., 2015]. More recently, Barutta et al. identified the cytosolic protein TNFAIP2 (tumor necrosis factor alpha-induced protein 2) as essential for TNT formation. TNFAIP2 facilitates the formation of TNTs that enable organelle transfer between podocytes. Overexpression of tnfaip2 in podocytes enhances TNT-mediated exchange of autophagosomes and lysosomes but concurrently impairs autophagic flux due to lysosomal dysfunction. Importantly, functional lysosomes counteracted AGE-induced lysosomal impairment and apoptosis, underscoring the protective role of TNT-mediated organelle transfer in diabetic nephropathy [Barutta et al., 2023]. Collectively, these advances across various diseases, underscoring the therapeutic potential of targeting TNT-associated autophagy communication pathways in many illnesses [Ottonelli et al., 2022; Venkatesh et al., 2019]. Table 1 Tunneling channel or nanotube mediated cell-cell interaction in many different cells Abbreviations: B-ALL, B-cell acute lymphoblastic leukemia; BMDMs, bone marrow-derived macrophages; CMs, cardiomyocytes; CTNS, Cystinosin, Lysosomal Cystine Transporter; ECs, endocardial cells; ICAM1, Intercellular Adhesion Molecule 1; HSPC, hematopoietic stem and progenitor cell; MSCs, mesenchymal stromal cells; Myo10, molecular motor myosin-X; PC12 cells, pheochromocytoma cells; PM, plasma membrane; TNFAIP2, tumor necrosis factor alpha-induced protein 2. 3. Normal autophagy is essential for mammalian cardiac development The role of autophagy in cardiac development was first recognized when knockout of Beclin1, a gene critical for autophagy lead to early embryonic lethality [Yue et al., 2003; Mizushima et al., 2010]. Since then, Parkin-directed mitophagy has also been shown to play a critical role during perinatal cardiac metabolic maturation [Gong et al., 2015]. Cardiac specific deletion of autophagy related genes in mouse embryo have further demonstrated the irreplaceable role normal autophagy plays in embryonic cardiac development [Mizushima et al., 2010]. 3.1 Beclin 1-E2F-PI3K/AKT pathway autophagy regulation is indispensable for early embryonic development Autophagy performs an essential role in early embryonic development through cellular reprogramming. As a critical component of autophagy regulation, Beclin 1 induces autophagy in mammalian development via the PI3K/AKT signaling axis. In both Beclin 1-/- mice and oocyte-specific Atg5 knockout mice, the loss of autophagic activity leads to early embryonic lethality [Yue et al., 2003; Mizushima et al., 2010]. The BECLIN 1-dependent autophagic process in fertilized oocytes is particularly vital for the transition from oocyte to early embryonic cells [Mizushima et al., 2010]. This process relies on autophagy dependent degradation of maternal proteins and the activation of the zygotic genome. Without normal autophagy, existent proteins cannot be broken down to ensure adequate amino acid building blocks for embryonic protein synthesis and whole sale remodeling of oocyte. 3.2 Tissue-specific deletion of autophagy-related genes in mice result in tissue/organ defects Mammalian autophagy genes play a pivotal role during two phases of embryonic development: transition from oocyte-to-embryo and embryo-to-neonate. The oocyte-to-embryo transition marks the earliest developmental stage where autophagy is triggered. After fertilization, autophagic activity is rapidly induced for protein degradation and the reprogramming of the zygote [Mizushima et al., 2010]. In Atg5-/- oocyte-specific knockout mice, absence of autophagy results in failure to survive past the transition from four-cell to eight-cell stage. These embryos arrest at the four-cell stage and undergo apoptosis. Following successful gestation, autophagy also plays a pivotal role in the embryo-to-neonate transition. After birth, neonates face a sudden lack of steady nutrient inflow as placental nutrient supply is cut off. Autophagy plays a vital role in maintaining amino acid pools and providing energy for neonatal tissues prior to enteric nutrition [Mizushima et al., 2010]. This is especially important in the highly metabolically active tissues of the heart, diaphragm, and skeletal muscles. Deficiency in autophagic genes Atg3, Atg5, Atg7, and Atg9 leads to neonatal lethality within the first day due to the inability to meet the high energy demands and nutrient requirements of the neonate [Mizushima et al., 2010]. Mice with knockdowns in these genes experience failed autophagic degradation and are thus unable to recycle unnecessary protein or convert glycogen stores into usable building blocks. Without these critical nutrients, these mice experience universal neonatal lethality to degrade and use proteins and glycogen stores to provide critical nutrients during early postnatal development [Mizushima et al., 2010]. These findings prove autophagy serves as a vital cellular "check-point" in developing embryonic tissue/organs during transitions between developmental stages. 3.3 Autophagy in heart morphogenesis and cardiac function maturation Multiple experiments have demonstrated autophagy to be critically important for cardiac morphogenesis. Recently, Amatruda's group systemically examined autophagy's role in zebrafish cardiac development [Lee et al., 2014]. Using a gain-of-function model, they tracked fluorescent tagged autophagy reporter protein LC-3, and discovered LC-3 was expressed in mouse heart development along with somite tissues at the 10-and 15-cell somite stage embryos. LC3 were shown to be stably associated with the autophagosomal membrane [Tsukamoto et al., 2008; Mizushim et al., 2010; Lee et al., 2014]. Knock-down of autophagy genes atg5, atg7, and becn1 generated autophagy-deficient zebra fish, which exhibited multiple defects in heart development. These defects included irregular cardiac looping, abnormal chamber morphology, aberrant valve development, and chamber septation [Lee et al., 2014]. Those defects reflect those found in mammal models and further suggests evolutionary conservation [Tsukamoto et al., 2008; Mizushima et al., 2010]. To elucidate the role of autophagy in the heart outside of development, Chávez et al demonstrated that autophagy performs cardioprotective and pro-survival modulating functions during zebrafish heart regeneration [Tsukamoto et al., 2008; Mizushima et al., 2010; Lee et al., 2014]. The hearts of zebra fish expressing fluorescently tagged LC-3 injured by ventricular apex resection demonstrated persistent LC3-I and Beclin 1 expression 3-7 days post injury as healing began [Chávez et al., 2020]. Rapamycin treatment activated 4E-BP1 expression and lead to poor wound healing. Their work highlighted the importance of tight autophagy regulation and balance in cardiac tissue recovery after injury [Chávez et al., 2020]. All evidence to date indicate autophagy is a fundamental cellular process vital to both normal cardiac morphogenesis and cardiac recovery. However, the exact balance of this essential cellular process is difficult to maintain as autophagy must be present during embryogenesis and healing, but overexpression leads to delayed healing. As an evolutionarily conserved cellular pathway for repair and energy generation, autophagy operates under a delicate balance that we are only beginning to understand. Further work into this field will likely yield new avenues of therapy for cardiac disease. 4. Conclusion and Perspective Autophagy is an evolutionarily conserved cellular function essential for life from embryogenesis to death. From the relatively simple heart tube of Drosophila to the anatomically complex four-chambered human heart, autophagy emerges as a central, evolutionarily preserved mechanism orchestrating cardiac development, physiological adaptation, healing, and age-related degeneration. Key molecular regulators of autophagy, such as mTOR, AMPK, ULK1, LAMP2A, and the PINK1/Parkin mitophagy pathway, and components of chaperone-mediated autophagy (CMA), are conserved across species and developmental stages. Normal autophagy is essential to normal cardiac development and functional recovery after myocardial injury. Abnormal autophagy has been implicated in the full spectrum of cardiac disease, from inherited genetic structural abnormalities to infectious cardiomyopathies like HIV-associated disease and cardiac disease from metabolic syndrome. The ubiquitousness of autophagy in embryonic development and diseases of pathologic cardiac remodeling represent a potential therapeutic target in which autophagy modulation could improve cardiac disease and recovery. Notably, the discovery of TNTs as microstructural conduits between endocardial and myocardial progenitors introduces a novel dimension to cardiac development. These actin-based structures, regulated by TNFAIP2 and lipophilic signaling mediators, facilitate intercellular communication during heart morphogenesis. The role of TNT in mediating autophagy and mitophagy may also play crucial roles in maintaining myocardial homeostasis in the adult heart. Although the full scope of their physiological and pathological significance remains to be elucidated, future research should prioritize integrative, cross-species investigations that capture the temporal dynamics of autophagy from embryogenesis through aging. Age-stratified profiling of autophagic flux, along with the development of targeted interventions—such as CMA activators and non-coding RNA-based therapies— will be instrumental in advancing mechanistic insight and clinical translation. Further work in how TNT regulates autophagy and the movement of cellular material between cells for communication and cellular repair should also be explored. Conceptualizing autophagy as a conserved and integrative biological thread offers not only a unifying framework for understanding cardiac health and disease but also a promising foundation for novel therapeutic strategies across many different diseases.