Related Experiment Video
Updated: Jan 15, 2026
Author Spotlight: Unveiling Mitochondrial Contact Sites and Architectural Insights
Published on: June 16, 2023
Enhanced mitochondria-associated membrane formation in Fuchs endothelial corneal dystrophy: a novel link between
Saki Matusmoto1, Saori Kadoya1, Yuna Horiuchi1
1Department of Biomedical Engineering, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, 610-0394, Japan.
Purpose:
To investigate the presence and characteristics of mitochondria-associated membranes (MAMs) in Fuchs endothelial corneal dystrophy (FECD) and to assess the relationship between endoplasmic reticulum (ER) stress and MAM formation in corneal endothelial cells, given the established roles of mitochondrial dysfunction and ER stress in FECD pathogenesis.
Study Design:
Experimental laboratory investigation.
Methods:
Corneal endothelial tissues from FECD patients and controls were examined by use of transmission electron microscopy to evaluate the ultrastructural features of mitochondria-ER contacts. An established FECD cell model was used for immunofluorescence colocalization analysis and protein expression profiling. Experimental models of protein misfolding (MG132) and direct ER stress induction (tunicamycin) were implemented to explore the relationship between ER stress and MAM formation.
Results:
The FECD specimens exhibited extensive mitochondria-ER contacts with evident tethering complexes and distances reduced to <20 nm when compared with normal corneal endothelium. Quantitative analysis showed significantly increased mitochondria-ER colocalization in iFECD cells (P <0.01). The FECD cell model showed significant upregulation of MAM-associated proteins, including GRP75, Mfn1, Mfn2, Sigma1 receptor, VDAC, and IP3R. MG132 and tunicamycin treatments both increased MAM formation while activating all UPR pathways.
Conclusions:
This study provides the first evidence of enhanced MAM formation in FECD and identifies ER stress as a key driver of this structural change. While these findings suggest a potential role for MAMs in linking ER stress and mitochondrial dysfunction in FECD pathogenesis, further investigation is needed to clarify whether such changes are protective adaptations or whether they contribute to disease progression.
Insights
Fuchs endothelial corneal dystrophy (FECD) shows increased mitochondria-associated membranes (MAMs), driven by endoplasmic reticulum (ER) stress. This study links ER stress, MAMs, and mitochondrial dysfunction in FECD pathogenesis.
Area of Science:
- Cell biology
- Ophthalmology
- Pathogenesis research
Background:
- Fuchs endothelial corneal dystrophy (FECD) is linked to mitochondrial dysfunction and endoplasmic reticulum (ER) stress.
- Mitochondria-associated membranes (MAMs) are critical contact sites between the ER and mitochondria, involved in cellular homeostasis.
Purpose of the Study:
- To investigate the presence and characteristics of MAMs in FECD.
- To assess the relationship between ER stress and MAM formation in corneal endothelial cells in FECD.
Main Methods:
- Transmission electron microscopy of human corneal tissues (FECD patients and controls).
- Immunofluorescence colocalization and protein expression profiling in an FECD cell model.
- Experimental induction of ER stress using MG132 and tunicamycin.
Main Results:
- FECD tissues showed increased mitochondria-ER contacts with reduced distances (<20 nm).
- FECD cell models exhibited significantly increased mitochondria-ER colocalization and upregulation of MAM-associated proteins.
- ER stress induction significantly increased MAM formation and activated unfolded protein response (UPR) pathways.
Conclusions:
- This study provides the first evidence of enhanced MAM formation in FECD.
- Endoplasmic reticulum stress is identified as a key driver of increased MAM formation in FECD.
- MAMs may link ER stress and mitochondrial dysfunction in FECD pathogenesis, requiring further investigation.
More Related Videos
12:36A Human Corneal Organ Culture Model of Descemet's Stripping Only with Accelerated Healing Stimulated by Engineered Fibroblast Growth Factor 1
Published on: July 22, 2022
10:32Mitochondria-associated ER Membranes MAMs and Glycosphingolipid Enriched Microdomains GEMs: Isolation from Mouse Brain
Published on: March 4, 2013
Related Concept Videos
01:28The Inner Mitochondrial Membrane
01:45Mitochondrial Membranes
01:17Role of ER in the Secretory Pathway
Components of the secretory pathway
About a third of proteins synthesized in the cell are sorted via the secretory route. They shuffle between different compartments in membrane-bound vesicles until they reach their final destination. The main intracellular compartments involved...
01:12Porin Insertion in the Outer Mitochondrial Membrane
Three models describe the assembly of porins by the SAM complex and their insertion into the outer membrane. Model 1 suggests that porins are assembled outside the SAM channel as the...
01:19Translocation of Proteins into the Mitochondria
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
01:21Smooth Endoplasmic Reticulum
The ER provides optimal conditions for synthesizing steroid hormones and lipids, such as phospholipids and triglycerides. Traditionally, lipid metabolism was considered to be a smooth ER function. However, there is no direct evidence to prove that rough ER is completely excluded from lipid...