视网膜干细胞的研究进展

Progress in retinal stem cells research

临床上常见的视网膜疾病，如年龄相关性黄斑变性（AMD）、糖尿病视网膜病变（DR）以及视网膜色素变性（RP）等，都是以光感受器细胞的进行性、不可逆性损伤为共同特征，最终导致失明。干细胞治疗被认为是治疗视网膜疾病最具前景的方法之一。以往的研究表明，在低等脊椎动物中，如两栖类和鱼类，其视网膜在损伤后可以由视网膜干细胞（RSCs）进行自我修复。最近的研究还发现，在哺乳类动物眼中也存在着RSCs，而且在某些外在因素的刺激下可以重新分化成视网膜神经细胞。就RSCs的来源及影响其增生分化的相关因素进行综述。

Retina is subjected to many acquired and inherited neuronal degenerative diseases such as agerelated macular degeneration （ AMD）, diabetic retinopathy （DR） and retinitis pigmentosa （RP）. All of these diseases are associated with the progressive damage and loss of photoreceptors, which is causing visual impairment and irreversible blindness. Stem-cell therapy is being widely considered as a promising treatment of these incurable retina diseases. However,in mammals including humans, there seems to be little or no recovery of lost ceils. By contrast, nonmammalian vertebrates, such as amphibians and fish, have robust regenerative responses to injury, which can lead to the near complete restoration of the neurons lost through injury. Nevertheless, over the past several years, studies have investigated that stem cells do exist in the adult mammalian eyes, and at least some types of neurons can be regenerated in the mammalian retina by stimulating with growth factors or transcription factors. These recent results suggest that some part of the regenerative program occurring in lower vertebrates remains in the mammalian retina. Here, the origin of various of adult retinal stem cells for the self-renewal and proliferation, and the relevant influencing factors were summarized.