Nutrient microenvironments reprogram RPE metabolism

Area of Science:

• Cell Biology
• Metabolic Engineering
• Ophthalmology

Background:

• Induced pluripotent stem cell-derived retinal pigment epithelium (iPSC RPE) is vital for studying age-related macular degeneration (AMD).
• Inconsistent RPE culture media composition hinders reproducible research on RPE metabolism and phenotype.

Purpose of the Study:

• To systematically investigate how six different nutrient microenvironments affect RPE phenotype, function, and metabolism.
• To compare these effects in both iPSC RPE and fetal RPE (fRPE) models.

Main Methods:

• Cultured iPSC RPE and fRPE in six distinct media: MEMα, DMEM-HG/F12, HPLM+FBS, HPLM+B27, and X-VIVO 10.
• Assessed RPE markers, cell morphology, transepithelial resistance, and metabolic profiles (amino acids, lipids, nucleotides).

Main Results:

• B27 and X-VIVO 10 media enhanced RPE cell size, hexagonality, and barrier function.
• Specific media induced distinct metabolic changes: HPLM+FBS led to lipid accumulation, X-VIVO 10 caused vacuole formation, and B27 supplementation boosted respiration.
• Metabolite analysis revealed condition-dependent shifts in consumption/production for creatine, serine, taurine, riboflavin, and guanine.

Conclusions:

• The nutrient microenvironment is a critical determinant of RPE phenotype, function, and metabolism.
• This study provides essential data for selecting appropriate media and interpreting results in RPE disease modeling, particularly for AMD.