miRNAs in embryonic stem cells during retinal differentiation

 描述（由申请人提供）：许多导致视力障碍和失明的视网膜退行性疾病涉及视网膜中光感受器的丧失。目前的治疗方法延缓了疾病的进展，但不能阻止或逆转光感受器的丧失。在动物研究中，使用胚胎干细胞（ESC）衍生的视网膜神经元的细胞疗法已经显示出有希望的结果;细胞整合到宿主视网膜中并恢复一些光反应。在我的职业生涯中，我设想专注于使人类胚胎干细胞更接近临床应用，将它们用作移植的无限细胞来源，以恢复视网膜变性患者的视力。为了实现这一目标，我将继续我的博士后培训， 博士华盛顿大学的托马斯雷。Reh博士和他的实验室为这一提议提供了最好的环境; Reh博士是视网膜发育、视网膜再生和ESC分化为视网膜神经元的先驱。此外，他还指导了许多博士后研究员走向成功的学术生涯。在他的指导下，我将研究miRNAs及其靶点在视网膜分化过程中ESCs中的作用。目前，从mESC和hESC分别产生视网膜神经元需要数周至数月。加速分化将使hESC成为更可行的治疗选择。在小鼠视网膜中，miRNAs已被证明可调节发育; Let-7a、miR-125 b和miR-9（晚期前生殖器-miRNAs）的过表达可加速发育时间。此外，这种作用是由它们的直接靶点Lin 28 b和Protogenin介导的，这两种蛋白质中的任何一种的过表达都会减缓发育。我们假设miRNA及其靶点调节小鼠和人类胚胎干细胞分化的时间与小鼠相似。在目标1中，我将测试LP-miRNA的过表达是否会加速mESC衍生的视网膜的发育。在目标2中，我将确定Lin 28 b和Prtg是否在体内和mESC培养中调节时间。我还将进行结构-功能研究，以研究Prtg如何介导这种效应。这些拟议的研究将扩大我们对控制发育时机的因素的理解，并有助于更有效地从ESC中获得视网膜神经元，用于细胞治疗。

 DESCRIPTION (provided by applicant): Many retinal degenerative diseases that lead to vision impairment and blindness involve the loss of photoreceptors in the retina. Current therapies delay the progression of disease, but they do not prevent or reverse the loss of photoreceptors. In animal studies, cellular therapy using embryonic stem cell (ESC)-derived retinal neurons have shown promising results; the cells integrate into the host retina and restore some light response. For my career, I envision focusing on bringing human ESCs closer to clinical application, using them as an unlimited source of cells for transplants to restore vision in patients with retinal degeneration. To achieve this, I will continue my postdoctoral training under Dr. Thomas Reh at the University of Washington. Dr. Reh and his laboratory provide the best environment for this proposal; Dr. Reh is a pioneer in retinal development, retinal regeneration and differentiation of ESCs into retinal neurons. In addition, he has mentored many postdoctoral fellows towards successful academic careers. Under his guidance, I will study the role of miRNAs and their targets in ESCs during retinal differentiation. It currently takes several weeks to months to produce retinal neurons from mESCs and hESCs, respectively. Speeding up differentiation will make hESCs a more viable therapeutic option. In the mouse retina, miRNAs have been shown to regulate development; overexpression of Let-7a, miR-125b, and miR-9 (Late Progenitor-miRNAs) accelerate developmental timing. Furthermore, this effect is mediated by their direct targets, Lin28b and Protogenin, and overexpression of either of these two proteins slowed down development. We hypothesize that miRNAs and their targets regulate timing in differentiating mouse and human ESCs similarly as in the mouse. In Aim 1, I will test whether overexpression of LP-miRNAs will accelerate development of mESC-derived retina. In Aim 2, I will determine whether Lin28b and Prtg regulate timing in in vivo and in mESC cultures. I will also perform structure-function studies to examine how Prtg may mediate this effect. These proposed studies will expand our understanding of the factors that control developmental timing, and help derive retinal neurons from ESCs more efficiently for use in cell therapy.