Molecular Assessment of Epiretinal Membrane: Activated Microglia, Oxidative Stress and Inflammation

Area of Science:

• Ophthalmology
• Retinal Biology
• Cellular and Molecular Medicine

Background:

• Epiretinal membranes (ERMs) form on the inner limiting membrane (ILM), altering retinal structure and function.
• ERM formation is common in inflammatory eye conditions such as proliferative diabetic retinopathy (PDR) and retinal detachment (RD).
• Current surgical ERM peeling can cause retinal distortion, necessitating alternative treatment strategies.

Purpose of the Study:

• To investigate the cellular composition and gene expression profile of ERMs from patients with PDR and RD.
• To identify key molecular pathways involved in ERM formation in inflammatory ocular conditions.

Main Methods:

• Ultrastructural microscopy and immunofluorescence analyses were performed on patient-derived ERM samples.
• Gene expression profiling focused on identifying signatures related to oxidative stress, inflammation, and specific signaling pathways.

Main Results:

• Activated microglia, astrocytes, and Müller glia were identified within ERMs from PDR and RD patients.
• ERMs from RD and PDR samples exhibited significantly higher expression of inflammation and oxidative stress-related genes compared to macular hole samples.
• Differential gene expression of hypoxia-inducible factor 1-α (HIF1-α), proinflammatory cytokines, and Notch, Wnt, and ERK signaling pathways was observed in RD and PDR ERMs.

Conclusions:

• The cellular makeup of ERMs includes activated glial cells, particularly in inflammatory conditions.
• Specific gene expression patterns, including inflammatory and signaling pathway markers, are associated with ERM formation in PDR and RD.
• These findings offer insights for developing novel therapeutic approaches to prevent or treat ERM formation.