Muller glia-derived exosomes and their microRNA cargo–potential for glaucoma therapies

Neuroprotection has been an important subject of research on the development of new therapies for glaucoma. Investigations into the use of stem cells to advance glaucoma treatments implicate neuroprotective factors as the major effectors on the improvement of retinal function, as it has been suggested that neurotrophic factors released by stem cells are responsible for the recovery of function upon cell transplantation. In the knowledge that neurotrophic factors are short-lived, it is conceivable that neuroprotection might be effected by molecules contained within extracellular vesicles (EVs) released by these cells. Müller glia provide a strong metabolic and neuroprotective role in the neural retina and it might be possible that EVs derived from these cells have the potential to deliver sustained neuroprotection to retinal ganglion cell (RGC) and optic nerve in glaucoma. It is suggested that micro-RNAs, which constitute the main EVs cargo, may possibly be more efficient in promoting negative regulation of gene expression leading to RGC death. Recent research shows that a population of Müller glia with stem cell characteristics can easily be isolated and propagated from retinal organoids formed by pluripotent stem cells and that these cells may constitute an invaluable source of EVs for glaucoma therapies. Further research into these approaches is the subject of intensive research.