Neural retinal regeneration in the anuran amphibian Xenopus laevis post-metamorphosis:: Transdifferentiation of retinal pigmented epithelium regenerates the neural retina
Neural retinal regeneration in the anuran amphibian Xenopus laevis post-metamorphosis:: Transdifferentiation of retinal pigmented epithelium regenerates the neural retina
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DOI：
10.1016/j.ydbio.2006.11.024
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发表时间：
2007-03-01
影响因子：
2.7
通讯作者：
Araki, Masasuke
中科院分区：
文献类型：
--
作者：
Yoshii, Chika;Ueda, Yoko;Araki, Masasuke
像蝾螈这样的有尾目两栖动物，视网膜和透镜的完全再生贯穿于它们的一生。相反，无尾两栖动物只在幼虫阶段保留这种能力，并在变态过程中迅速失去这种能力。据信，它们在变态后无法再生这些组织。然而，与这种普遍接受的观念相反，在这里，我们报告说，神经视网膜（NR）和透镜再生后，手术切除这些组织的无尾两栖动物，非洲爪蟾，甚至在成熟的动物。NR既可由视网膜色素上皮（RPE）细胞通过转分化再生，也可由睫状体边缘区（CMZ）干细胞通过分化再生。在NR再生的早期阶段（术后5-10天），RPE细胞似乎从RPE层脱层并粘附到剩余的视网膜血管膜上。此后，它们经历转分化以再生NR层。体外培养研究还显示，RPE细胞分化为神经元，并且FGF-2和IGF-1的存在加速了这一过程。再生透镜的来源似乎是残留的透镜上皮，这表明这是一种修复过程而不是再生。因此，我们第一次表明，无尾两栖动物保留变态后的视网膜再生能力，类似于有尾目，但再生模式不同的两个订单。我们的研究提供了一个新的工具，通过提供一个替代的动物模型蝾螈，唯一的其他实验模型，参与视网膜和透镜再生的调控机制的分子分析。(c)2006年爱思唯尔公司All rights reserved.
In urodele amphibians like the newt, complete retina and lens regeneration occurs throughout their lives. In contrast, anuran amphibians retain this capacity only in the larval stage and quickly lose it during metamorphosis. It is believed that they are unable to regenerate these tissues after metamorphosis. However, contrary to this generally accepted notion, here we report that both the neural retina (NR) and lens regenerate following the surgical removal of these tissues in the anuran amphibian, Xenopus laevis, even in the mature animal. The NR regenerated both from the retinal pigment epithelial (RPE) cells by transdifferentiation and from the stem cells in the ciliary marginal zone (CMZ) by differentiation. In the early stage of NR regeneration (5-10 days post operation), RPE cells appeared to delaminate from the RPE layer and adhere to the remaining retinal vascular membrane. Thereafter, they underwent transdifferentiation to regenerate the NR layer. An in vitro culture study also revealed that RPE cells differentiated into neurons and that this was accelerated by the presence of FGF-2 and IGF-1. The source of the regenerating lens appeared to be remaining lens epithelium, suggesting that this is a kind of repair process rather than regeneration. Thus, we show for the first time that anuran amphibians retain the capacity for retinal regeneration after metamorphosis, similarly to urodeles, but that the mode of regeneration differs between the two orders. Our study provides a new tool for the molecular analysis of regulatory mechanisms involved in retinal and lens regeneration by providing an alternative animal model to the newt, the only other experimental model. (c) 2006 Elsevier Inc. All rights reserved.