Embryonic stem-cell-derived retinal pigment epithelial cells for macular degeneration

摘要

Steven Schwartz and colleagues' study on transplantation of retinal pigment epithelium derived from human embryonic stem cells (hESCs) for the treatment of macular degeneration (Feb 25, p 713) is an important step towards treatment of such disorders. We believe, however, that a basic issue regarding the rationale of this approach should be addressed.In this trial, a patient with advanced Stargardt's disease, and another with a geographic atrophy variant of age-related macular degeneration (AMD-GA), were treated. Increasing evidence supports a biochemical basis for photoreceptor degeneration in Stargardt's disease-ie, the abnormal accumulation of toxic diretinal compounds due to malfunctioning of the ABCA4 protein. This accumulation leads to degeneration of photoreceptor and retinal pigment epithelial cells via oxidative damage. According to this model, transplanted hESC-derived retinal pigment epithelial cells would be unlikely to survive, exposed as they are to the same pathological mechanism that affects the host cells.