Methods for Analyzing Endoplasmic Reticulum Stress in the Trabecular Meshwork of Glaucoma Models

Area of Science:

• Ophthalmology
• Cell Biology
• Pathophysiology

Background:

• Elevated intraocular pressure (IOP), a primary risk factor for glaucoma, is often linked to increased outflow resistance within the trabecular meshwork (TM).
• Progressive accumulation of misfolded proteins and subsequent endoplasmic reticulum (ER) stress are implicated in the pathophysiology of glaucomatous TM damage and IOP elevation.
• Known glaucoma triggers, such as mutant myocilin expression or dexamethasone treatment, induce protein misfolding and ER stress in TM cells.

Purpose of the Study:

• To investigate the role of protein misfolding and ER stress in trabecular meshwork (TM) dysfunction and elevated intraocular pressure (IOP).
• To establish a detailed protocol for analyzing ER stress and protein misfolding in TM cells and tissues.
• To correlate ER stress and unfolded protein response (UPR) mediators with glaucomatous TM damage and IOP elevation.

Main Methods:

• Utilized cell culture, mouse models, and human postmortem TM tissues.
• Employed genetic and pharmacological manipulations to study ER stress and UPR pathways.
• Developed and applied protocols for analyzing protein misfolding and ER stress markers in TM.

Main Results:

• Demonstrated that expression of mutant myocilin and dexamethasone treatment induce abnormal protein accumulation and ER stress in TM.
• Showed that TM cells activate the unfolded protein response (UPR) to cope with protein misfolding.
• Established a link between chronic ER stress, TM dysfunction, and elevated IOP.

Conclusions:

• Chronic ER stress and protein misfolding are key contributors to trabecular meshwork (TM) dysfunction and elevated intraocular pressure (IOP) in glaucoma.
• The described protocols provide a framework for investigating the mechanisms of glaucomatous damage.
• Understanding these pathways is crucial for developing targeted therapies for glaucoma.