The role of Injury signals in RPE Reprogramming

 描述(申请人提供)：在美国，导致失明和低视力的主要原因包括老年性黄斑变性、糖尿病视网膜病变和青光眼。目前的治疗方法对那些患有这些疾病晚期的人几乎没有选择。为了探索可能的治疗方法，重要的是使用具有再生能力的动物模型，如鸡胚胎。胚胎雏鸡在视网膜切除后，只要存在诱导因素，就通过对剩余的视网膜色素上皮(RPE)重新编程来再生它们的视网膜。这个重新编程的过程允许RPE去分化、增殖并形成神经上皮，最终分化生成视网膜。去分化的过程是理解RPE重新编程如何工作的关键。RPE重编程利用两步去分化过程，其中损伤(视网膜切除)刺激RPE变得有能力对诱导因素做出反应。我们已经确定了几个能够将RPE重新编程为神经视网膜的诱导因素，然而，这些分子在RPE重新编程中的作用仍不清楚。在这项建议中，我们将剖析诱导因子，如补体成分C3a，C5a和炎症相关分子，包括IL-6和抗氧化剂N-乙酰半胱氨酸(NAC)重新编程RPE的机制。具体地说，我们将探索这些因子/分子是否表现出相互依赖，它们是否需要共同的信号通路，或者它们是否使用类似或不同的表观遗传策略来调节共同的靶基因。我们将检验以下假设：诱导因子通过启动下游信号通路，如MAPK、PI3K、Wnt和/或Jak/Stat通路，引导RPE重新编程和视网膜再生，这些信号通路通常由生长因子和G偶联受体激活。通过这些途径，诱导因子表观遗传地控制调节RPE重新编程的共同基因。由于恢复视力的紧迫性，NEI宣布了一个大胆的目标，“通过再生眼睛和视觉系统中的神经元和神经连接来恢复视力”。本研究提供了一个模型系统，用于检测C3a、C5a、IL-6和NAC等小分子，以评估视网膜再生的诱导作用，并提供了一个剖析这一过程中涉及的细胞和分子机制的平台。这项工作将对再生医学领域产生重大影响，因为所获得的信息可以外推到包括人类在内的哺乳动物的视网膜修复过程，特别是人类RPE可能的重新编程以产生新的神经元。

 DESCRIPTION (provided by applicant): The leading causes of blindness and low vision in the US include AMD, diabetic retinopathy and glaucoma. Current therapies offer few options to those suffering from late stages of these diseases. In order to explore possible therapies, it is important to use animal models with regenerative capabilities such as the chick embryo. Embryonic chicks regenerate their retina, following retinectomy, by reprogramming the remaining retinal pigmented epithelium (RPE) as long as an inducing factor is present. This reprogramming process allows the RPE to dedifferentiate, proliferate and form a neuro-epithelium that eventually differentiates generating retina. The process of dedifferentiation is ke to understanding how RPE reprogramming works. RPE reprogramming utilizes a two-step dedifferentiation process where injury (retinectomy) stimulates the RPE to become competent to respond to inducing factors. We have identified several inducing factors that are able to reprogram the RPE to neural retina, however, the role for these molecules in RPE reprogramming remains unknown. In this proposal we will dissect the mechanisms by which inducing factors such complement components C3a, C5a and inflammation associated molecules including IL-6 and antioxidant N-acetyl cysteine (NAC) reprogram the RPE. Specifically, we will explore if these factors/molecules exhibit interdependence, if they require common signaling pathways or if they regulate common target genes using similar or distinct epigenetic strategies. We will test the following hypothesis: Inducing factors direct RPE reprogramming and retina regeneration by initiating downstream signaling cascades such as MAPK, PI3K, Wnt and/or Jak/Stat pathways commonly activated by growth factor and G-coupled receptors. Through these pathways, the inducing factors epigenetically control common genes that regulate RPE reprogramming. The urgency for restoring vision lead the NEI to announce an audacious goal "to restore vision through regeneration of neurons and neural connections in the eye and visual system". This study provides a model system where to test small molecules such as C3a, C5a, IL-6 and NAC to evaluate induction of retina regeneration and a platform where to dissect the cellular and molecular mechanisms involved in this process. This work will have a significant impact on the field of regenerative medicine since the information obtained can be extrapolated to the process of retina repair in mammals including humans, and specifically on the potential reprogramming of human RPE to generate new neurons.