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Updated: Sep 12, 2025
08:45
Determination of Mitochondrial Respiration and Glycolysis in Ex Vivo Retinal Tissue Samples
Published on: August 4, 2021
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Metabolic dysfunction promoted by mitochondrial DNA mutation burden drives retinal degeneration
Johnathon Sturgis1,2, Ke Jiang1,2, Stephanie A Hagstrom1,2
1Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA.
Biorxiv : the Preprint Server for Biology
|August 6, 2025
Summary
Mitochondrial DNA (mtDNA) mutations impair retinal metabolism, causing dysfunction in the retinal pigment epithelium (RPE) and contributing to vision loss in degenerative diseases.
Area of Science:
- Ophthalmology
- Mitochondrial Biology
- Cellular Metabolism
Background:
- Retinal degenerative diseases like AMD and glaucoma are linked to mitochondrial dysfunction.
- The specific impact of mitochondrial DNA (mtDNA) mutations on retinopathies remains under-explored.
- Previous studies identified aging-related retinal deficits in PolgD257A mutator mice (D257A).
Purpose of the Study:
- To investigate the effects of mtDNA mutations on the metabolic interplay between the retina and retinal pigment epithelium (RPE).
- To compare metabolic profiles in young and aged wild-type (WT) and D257A mice.
Main Methods:
- Seahorse analysis of cellular energy production in dissected retina samples.
- Immunofluorescence and Western blot experiments to assess protein expression.
- Analysis of mitochondrial respiration and glycolytic flux.
Main Results:
- Aged D257A mice showed reduced mitochondrial respiration and increased reserve capacity in retinal tissue.
- Decreased expression of electron transport chain proteins and glucose transporter 1 (GLUT-1) in D257A retina and RPE.
- Altered expression of glycolytic enzymes in aged D257A retina and RPE, with RPE utilizing glucose.
Conclusions:
- Accumulated mtDNA mutations lead to impaired retinal and RPE metabolism.
- Mitochondrial dysfunction in RPE promotes glycolysis, reducing metabolite availability for the neural retina.
- These findings offer insights into retinal degeneration mechanisms and the role of mtDNA mutations.
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