Retinal Stem Cells and Regeneration of Vision System

Abstract

The vertebrate retina is a well-characterized model for studying neurogenesis. Retinal neurons and glia are generated in a conserved order from a pool of mutlipotent progenitor cells. During retinal development, retinal stem/progenitor cells (RPC) change their competency over time under the influence of intrinsic (such as transcriptional factors) and extrinsic factors (such as growth factors). In this review, we summarize the roles of these factors, together with the understanding of the signaling pathways that regulate eye development. The information about the interactions between intrinsic and extrinsic factors for retinal cell fate specification is useful to regenerate specific retinal neurons from RPCs. Recent studies have identified RPCs in the retina, which may have important implications in health and disease. Despite the recent advances in stem cell biology, our understanding of many aspects of RPCs in the eye remains limited. PRCs are present in the developing eye of all vertebrates and remain active in lower vertebrates throughout life. In mammals, however, PRCs are quiescent and exhibit very little activity and thus have low capacity for retinal regeneration. A number of different cellular sources of RPCs have been identified in the vertebrate retina. These include PRCs at the retinal margin, pigmented cells in the ciliary body, iris, and retinal pigment epithelium, and M€ uller cells within the retina. Because PRCs can be isolated and expanded from immature and mature eyes, it is possible now to study these cells in culture and after transplantation in the degenerated retinal tissue. We also examine current knowledge of intrinsic RPCs, and human embryonic stems and induced pluripotent stem cells as potential sources for cell transplant therapy to regenerate the diseased retina. Anat Rec, 297:137-160,

Intermittent high oxygen influences the formation of neural retinal tissue from human embryonic stem cells

“…The vertebrate retina is a highly multilayered nervous tissue with a large diversity of cellular components and complex circuits 1 . Research in neurogenesis and retinogenesis is ongoing, including studies of basic neurogenesis 2 , gene networks 3 , extracellular matrix 4 , retinal stem cells 5 and oxygen concentration 6 . However, because of the limitations in ethics and morals of human experiments, studies on those topics are limited to animals, which do not completely represent the characteristics of humans.…”

Review of approaches to cell therapy in ophthalmology

“…Возможно, фармакологическая активация этих клеток-предшественников могла бы увеличить регенераторные возможности сетчатки. Однако на сегодняшний день восстановление сетчатки пытаются осуществить за счет трансплантации клеток, выращенных in vitro [106].…”

iPS Cells for Modelling and Treatment of Retinal Diseases

“…Retinal neural and pigment epithelial progenitor cells [ 23 , 24 ] have been found in the adult retina, but access to these cells is also limited, as they will require vitrectomy surgery, making them equally unsuitable for clinical use in testing therapeutics and administering personalised cell therapy. Multipotent neural stem cells capable of generating retinal lineages have also been found in the ciliary margin zone and corneoscleral limbus [ 25 , 26 , 27 , 28 ]. The former source is located adjacent to the lens within the eye, and it is even more difficult to access than the retina.…”