视网膜内源性干细胞研究进展

Advances of research on endogenous retinal stem cells

视网膜的神经细胞一旦损伤，便无法再生修复，利用干细胞疗法使神经细胞得到再生修复已成为当今研究的热点。视网膜中存在具有自我修复能力的内源性干细胞，激活视网膜中的内源性干细胞，利用其对损伤的视网膜神经元进行修复，具有重要的研究价值和应用前景，近年来受到世界神经生物学、眼科学等领域研究者的重视。鱼类、两栖类动物的视网膜具有较强的再生修复能力，而鸟类和哺乳类动物的视网膜的再生能力有限，且各类动物的视网膜再生存在各自的特征。睫状体边缘带、视网膜色素上皮细胞、Muller细胞等细胞都是视网膜再生可能的细胞来源，如鱼类、鸟类和哺乳类动物新生成的视网膜细胞来自于视网膜Muller细胞，而两栖类动物再生的视网膜则来源于视网膜色素上皮细胞。各种视网膜内源性干细胞需要被活化后才能发挥干细胞特性对损伤的视网膜神经细胞进行修复，激活这些细胞的方法有多种，如利用兴奋性氨基酸、生长因子、转录因子、细胞内信号等。本文就不同物种，包括鱼类、两栖类、鸟类和哺乳类动物在内的视网膜的再生能力、睫状体边缘带、视网膜色素上皮细胞、Muller细胞等不同的视网膜内源性神经干细胞的来源及各种能够活化视网膜内源性干细胞进行增生和分化的因素的相关研究进展进行综述。

The retinal neurons can not repair or regenerate once they are injured. Repairing the injured neurons by stem cell therapy is a hotspot in current study field. Endogenous stem cells exist in retina,which have the potential to restore retinal neural cells. Stimulating the endogenous retinal stem cells and using them to repair the injured retina has important research value and broad application prospects. It draws attention from neurobiology and ophthalmology researchers all over the world. The retinal regeneration ability of fish and amphibians is strong,while it is quite limited in birds and mammals. The retina regrowth character varies in different species. Ciliary marginal zone, retinal pigmented epithelial cells, and MOiler cells are all potential cell sources for retinal regeneration. In fish, birds and mammals,the regenerated retinal neurons derived from MOiler cells,while in amphibians they derived from RPE cells. The endogenous retinal stem cells need to be activated before they generated into retinal neurons. Researchers reported several methods to activate those cells, including using excitatory amino acid, growth factor, transcription factor,and intracellular signals. Here we reviewed the recent advances about retinal regeneration in different species including fish, amphibians, birds, and mammals;also the different source of endogenous retinal stem cells, including ciliary marginal zone,retinal pigmented epithelial cell,and Muller cell. Also,we reviewed the activation factors which could activate the endogenous retinal stem cells to proliferate and differentiate.