Gene Regulation in Lens Regeneration

描述(申请人提供)：晶状体再生是一种独特的现象，仅限于一些尿毒症患者。晶状体切除后，虹膜背侧色素上皮细胞(PECs)转分化形成新晶状体。腹侧虹膜不参与这一过程。然而，有趣的是，当来自Newt的腹侧虹膜或来自任何动物(包括老年人)的色素上皮(PE)的细胞被长期培养时，它们会转化为晶状体。换句话说，来自许多物种的PECs能够再生晶状体，但在体内，这种能力只是一些蝾螈所独有的。这一提议的最初假设是，肯定有特定的基因在眼表的虹膜背侧和腹侧表达，这些基因可以帮助我们识别可能调节和诱导晶状体再生的因素。在过去的几年里，我们已经研究了几个基因的表达模式，并确定了几个很好的候选基因。这些基因分别是pax-6、Six-3、FGFR-1和prox-1。然后，我们提出这些基因可以用来转导缺乏向晶状体转分化能力的腹侧PECs，试图诱导晶状体再生。我们已经在两个不同的协议上取得了成功。在其中一组中，将Six-3基因导入腹侧PECs并用维甲酸处理，而在另一组腹侧虹膜中，用BMP途径的可溶性抑制剂处理。这些是诱导的第一个案例，我们现在想利用这一知识来了解其他动物晶状体再生的限制并进行诱导。在第一次成功地从腹侧虹膜诱导晶状体再生后，我们现在建议检查参与诱导的分子通路，并在其他通常不具备晶状体再生能力的动物中诱导晶状体再生，例如在Axolotl和小鼠中。这可能会导致对已建立的动物模型进行实验，最终可以更有效地应用于临床。

DESCRIPTION (provided by applicant): Lens regeneration is a unique phenomenon restricted only to some urodeles. Upon lentectomy the new lens is formed by the transdifferentiation of the dorsal iris pigment epithelial cells (PECs). The ventral iris does not contribute to the process. What is interesting, however, is that when cells, from the ventral iris of the newt or from the pigmented epithelium (PE) of any animal including old humans, are placed in culture for long periods of time, they transdifferentiate to lens. In other words, PECs from many species are capable for lens regeneration, but in vivo, this capacity is unique to some newts only. The original hypothesis of this proposal was that there must be specific genes expressed in the dorsal versus the ventral iris of the newt eye that could help us identify factors that might regulate and induce lens regeneration. In previous years, we have studied expression patterns of several genes and we have identified several good candidates for such role. These genes were pax-6, six-3, FGFR-1 and prox-1. We then proposed that these genes could be used to transfect ventral PECs, which lack the ability to transdifferentiate to lens, in an attempt to induce lens regeneration. We have been successful with two different protocols. In one of them, ventral PECs were transfected with six-3 and treated with retinoic acid and in the other ventral irises were treated with a soluble inhibitor of the BMP pathway. These are the first cases of induction and we now would like to utilize this knowledge to understand the restriction of lens regeneration in other animals and to induce it. Having succeeded for the first time in inducing lens regeneration from the ventral iris, we now propose to examine the molecular pathways that are involved in the induction due to the treatments and to induce lens regeneration in other animals that are normally incompetent of lens regeneration, such as in the axolotl and mice. This might lead to experimentation with established animal models, which eventually can be used more efficiently in clinical applications.