MINI REVIEW article
Front. Neurosci.
Sec. Neurodegeneration
This article is part of the Research TopicInter-organelle membrane contacts in health and disease of the nervous systemView all articles
Sigma Receptors and Mitochondria-Associated ER Membranes Are Converging Therapeutic Targets for Alzheimer’s Disease
Provisionally accepted
- Massachusetts General Hospital, Harvard Medical School, Boston, United States
Select one of your emails
You have multiple emails registered with Frontiers:
Notify me on publication
Please enter your email address:
If you already have an account, please login
You don't have a Frontiers account ? You can register here
Alzheimer’s disease (AD) begins decades before clinical symptoms emerge. The “amyloid hypothesis” suggests that amyloid-β (Aβ) deposition initiates a cascade of tau hyperphosphorylation, neuroinflammation, and neuronal loss leading to cognitive decline. The recent success of anti-Aβ therapies such as Leqembi in prodromal or mild cognitive impaired patients underscores the importance of early intervention and Aβ clearance. However, safety and cost limitations highlight the need for alternative therapeutic strategies. Small-molecule modulators of Sigma-1 and Sigma-2 receptors (σ1R and σ2R) have emerged as promising candidates for AD treatment. σ1R agonists exhibit neuroprotective and anti-amnestic effects under pathological conditions without affecting normal cognition. Beyond AD, σ1R is implicated in several neurodegenerative diseases including ALS, Parkinson’s, and Huntington’s diseases, stroke, and epilepsy. σ1R plays a key role at mitochondria-associated ER membranes (MAMs)—specialized lipid raft-like domains that form functional membrane contact sites between the endoplasmic reticulum (ER) and mitochondria. β-secretase (BACE1), γ-secretase, and their substrates APP and palmitoylated APP (palAPP) localize in the MAMs, promoting amyloidogenic Aβ production. MAMs serve as dynamic hubs for inter-organelle communication, calcium signaling, and lipid metabolism. The “MAM hypothesis” proposes that MAM dysregulation drives early AD pathology and persists throughout disease progression, contributing to neurofibrillary tangle formation, calcium imbalance, and neuroinflammation. This review aims to summarize the current understanding of σ1R-mediated regulation of MAMs and its neuroprotective mechanisms, highlighting potential therapeutic opportunities for targeting σ1R in AD and other neurodegenerative disorders.
Keywords: Sigma-1 and -2 Receptors, σ1R agonists, Amyotrophic Lateral Sclerosis, Alzheimer's diseases, Huntington and parkinson diseases, Mitochondria-associated ER membrane
Received: 27 Oct 2025; Accepted: 24 Nov 2025.
Copyright: © 2025 Bhattacharyya, Lotlikar and Zellmer. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Raja Bhattacharyya
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.