Oxidized-LDL Induces Metabolic Dysfunction in Retinal Pigment Epithelial Cells

Area of Science:

• Ophthalmology and Vision Science
• Cellular Metabolism
• Mitochondrial Biology

Background:

• Mitochondrial dysfunction is increasingly recognized as a key factor in age-related macular degeneration (AMD) pathogenesis.
• Metabolic imbalances, including disruptions in oxidative phosphorylation (OXPHOS) and glycolysis, are linked to mitochondrial damage.
• Oxidized low-density lipoprotein (ox-LDL) accumulates in retinal deposits (drusen) in AMD patients.

Purpose of the Study:

• To investigate whether ox-LDL directly causes metabolic alterations in retinal pigment epithelial (RPE) cells.
• To determine the impact of ox-LDL exposure on key metabolic pathways within RPE cells.
• To compare the suitability of different cell models for studying AMD-related metabolic changes.

Main Methods:

• RPE cells were exposed to varying concentrations and durations of ox-LDL.
• Assessed changes in fatty acid β-oxidation (FAO), OXPHOS, and glycolysis.
• Measured mitochondrial reactive oxygen species (ROS) production.
• Compared metabolic activity and barrier function of ARPE-19 cells versus induced pluripotent stem cell-derived RPE cells.

Main Results:

• Prolonged ox-LDL exposure induced significant metabolic alterations in RPE cells.
• Observed changes in FAO, OXPHOS, and glycolytic activity, alongside increased mitochondrial ROS production.
• Metabolic effects were dependent on ox-LDL concentration and treatment duration.
• ARPE-19 cells exhibited lower barrier function and FAO activity compared to iPSC-RPE cells.

Conclusions:

• Ox-LDL is a potential causative factor for metabolic disturbances in RPE cells relevant to AMD.
• Metabolic reprogramming in RPE cells by ox-LDL contributes to AMD pathogenesis.
• Findings highlight the importance of using appropriate cell models, like iPSC-RPE cells, for accurate AMD research.