Retinal stem cells and potential cell transplantation treatments

Abstract

The retina, histologically composed of ten delicate layers, is responsible for light perception and relaying electrochemical signals to the secondary neurons and visual cortex. Retinal disease is one of the leading clinical causes of severe vision loss, including age-related macular degeneration, Stargardt's disease, and retinitis pigmentosa. As a result of the discovery of various somatic stem cells, advances in exploring the identities of embryonic stem cells, and the development of induced pluripotent stem cells, cell transplantation treatment for retinal diseases is currently attracting much attention. The sources of stem cells for retinal regeneration include endogenous retinal stem cells (e.g., neuronal stem cells, Müller cells, and retinal stem cells from the ciliary marginal zone) and exogenous stem cells (e.g., bone mesenchymal stem cells, adipose-derived stem cells, embryonic stem cells, and induced pluripotent stem cells). The success of cell transplantation treatment depends mainly on the cell source, the timing of cell harvesting, the protocol of cell induction/transplantation, and the microenvironment of the recipient's retina. This review summarizes the different sources of stem cells for regeneration treatment in retinal diseases and surveys the more recent achievements in animal studies and clinical trials. Future directions and challenges in stem cell transplantation are also discussed.

Biobanking of Human Retinas: The Next Big Leap for Eye Banks?

“…Furthermore, both types of pluripotent cells are endowed with a tumorigenic potential based on greater genomic instability [26]. Additionally, although autologous bone marrow‐derived stem cells are likely to be less immunogenic after transplantation as hESCs, they are usually only available in very limited amount and could further secrete proangiogenic factors, which are avoided in exudative AMD [1, 25].…”

“…Retinal degenerative diseases (RDDs) caused by inherited monogenetic defects (Stargardt's disease, retinitis pigmentosa [RP]) or acquired multifactorial retinal diseases (age-related macular degeneration [AMD], glaucoma, and diabetic retinopathy) are one of the main clinical causes of often incurable, progressive, and severe visional impairment in the developed world [1]. Thus, extensive research effort is put into the development of new therapeutic options, of which regenerative stem cell (SC)-based therapies are currently attracting much attention.…”

Proceedings: Debilitating Eye Diseases

“…Given the genetic heterogeneity associated with the disease and the lack of therapeutic options, cell therapy seems a promising therapeutic avenue for RP patients, but perhaps not initially as cell replacement therapy. In contrast to AMD, in which the degenerated area is limited to the macula region, a cell therapy that aims to replace a damaged tissue may not be suited for the correction of the relatively large area of the retina damaged in RP patients; however, cell therapy that uses cells to provide trophic support to the rod and cone cells may be effective to slow the progression of the disease [6].…”

Combined Transplantation of Olfactory Ensheathing Cells With Rat Neural Stem Cells Enhanced the Therapeutic Effect in the Retina of RCS Rats

“…McGill et al showed that the transplantation of NSCs into the subretinal space (SRS) of RCS rats preserves retinal function and protects photoreceptors from death through the phagocytosis of photoreceptor outer segments (McGill et al, 2012). Lin et al (2014) found that NSCs have a better proliferative ability than that of retinal progenitor cells (RPCs). Moreover, upon treatment with transforming growth factor beta type III and retinoic acid, NSCs are able to differentiate into opsin-positive retinal cells (Lin et al, 2014).…”

“…Lin et al (2014) found that NSCs have a better proliferative ability than that of retinal progenitor cells (RPCs). Moreover, upon treatment with transforming growth factor beta type III and retinoic acid, NSCs are able to differentiate into opsin-positive retinal cells (Lin et al, 2014). Our previous work also confirmed the preservative effect of the subretinal transplantation of NSCs in rd1 mice (Li et al, 2016).…”