Recently, researchers reported the successful transplantation of retinal tissue derived from human embryonic stem cells in a primate model of retinitis pigmentosa. Retinitis pigmentosa is an inherited eye disease with few treatment options.
"Transplantation of retinal tissue derived from mouse embryonic stem cells (ESC) to mice has suggested the potential of this method to treat retinitis pigmentosa (RP). The hallmark of this genetic disease is the gradual loss of network photoreceptors. However, repeating such actions on primate models of retinal degeneration is largely lacking. Michiko Mandai and colleagues transplanted retinal slices derived from human embryonic stem cells (ESC) into the subretinal space of a rat model of advanced retinitis pigmentosa (RP), and found that these transplanted slices mature into multiple well-organized layers. It has an inner layer of photoreceptors and an outer layer of pigment, and is integrated with the host retina. Next, the authors used subretinal cobalt chloride injection or laser coagulation to develop two trauma-induced end-stage retinitis pigmentosa (RP) models of cynomolgus and rhesus monkeys. Optical coherence tomography and immunohistochemical analysis revealed that when retinal slices derived from human embryonic stem cells (ESC), which have been differentiated for about 60 days, were transplanted into the eyes of these monkey models, these slices survived, matured, and survived. In some cases, it showed signs of integration with the bipolar cells of the visual network of these monkeys, and the thickness of the transplantation increased until 120 days after differentiation and stabilization. Therefore, the authors propose that a fully differentiated and well-positioned retinal transplant can form synaptic connections with the bipolar cells of the primate recipient's retina. According to the authors, these monkey models may help optimize research conditions for retinal transplantation and surgery for the treatment of human retinitis pigmentosa (RP).