Stem Cells for Microenvironmental Modulation and Retinal Regeneration

Retinal degeneration due to injury or disease can be a devastating event to the quality of life of an individual. Efforts to develop strategies for retinal repair and regeneration have been challenging due to the complexities in the microenvironment necessary to support and maintain retinal function, as well as the difficulty in guiding the correct integration of regenerating cells to the existing neural networks. Stem cell therapies have recently emerged as a viable option to promote retinal repair and regeneration with encouraging results. As more studies are performed on the effect of stem cells on the regenerative processes in the retina, it becomes clear that stem cells can play a beneficial role not only by their differentiation capabilities and cellular replacement potential, but also as modulators of local environmental factors to provide conditions that are more conducive to functional repair and regeneration. Stem cells have been shown to be able to modulate several processes that are detrimental to regeneration such as inflammation, extracellular matrix remodeling, and loss of trophic support, among others. Here we review some of the latest studies on stem cell-mediated retinal regeneration by focusing primarily on how stem cells can modulate the microenvironment in the neural retina to augment its regenerative potential following injury or disease.