microRNAs targeting Kit inhibit the development and maintenance of ICC

描述(申请人提供)：卡哈尔间质细胞(ICC)是一种起搏细胞，能产生自发的电慢波，并调节胃肠道(GI)运动神经元的输入。ICC网络的缺失或缺陷直接与胃肠动力障碍有关。最近的研究表明ICC在糖尿病胃肠病(DGEP)的发生发展中起重要作用。DGEP患者表现为ICC网络缺失或缺陷，可能导致胃肠动力障碍。ICC表达受体酪氨酸激酶，KIT是干细胞因子的受体。KIT信号是胃肠道ICC正常发育和维持所必需的。因此，DGEP中ICC的丢失可能是KIT表达减少的结果。最近的研究表明，Kit的表达受microRNAs(MiRNAs)的调控。因此，我们的中心假设是miRNAs靶向Kit抑制DGEP中ICC的发展和维持。为了解决这一假设，我们提出了以下具体目标：1)ICC中microRNAome的特征，2)DGEP发生过程中microRNAs的变化，以及3)通过miRNAs靶向试剂盒抑制ICC的生长和维持。为了达到特定的目的，我们将利用我们最近培育的两个动物模型Kit+/CopGFP和2型糖尿病Kit+/CopGFP；Lepob/ob突变小鼠。两只小鼠都以Kit特异性的方式表达了明亮的绿色荧光蛋白CopGFP，这为研究ICC表型的功能和遗传调控提供了一个强大的新模型。完成这个项目的具体目标将提供关于ICC特定表达的miRNAs的信息，以及在一种主要的GI运动障碍中这部分调控分子是如何改变的。我们的初步数据表明，ICC中的许多miRNA都以Kit为靶标。这项研究将描述一种新的分子机制，涉及抑制KIT表达的miRNAs。这是一个令人兴奋的机会，可以了解KIT在ICC中的表达是如何调控的，以及ICC在DGEP的发展过程中是如何丢失的。MiRNAs抑制试剂盒表达的鉴定可能有助于开发一种治疗性的反义miRNA药物，该药物可能有助于阻断或逆转DGEP和其他发生ICC丢失的胃肠动力和功能障碍中受损的ICC网络。 公共卫生相关性：Cajal间质细胞丢失(ICC)与糖尿病胃肠病(DGEP)直接相关，但ICC中断的分子机制尚不清楚。本研究试图揭示一种新的机制，涉及到在DGEP发生过程中导致ICC丢失的microRNAs。

DESCRIPTION (provided by applicant): Interstitial cells of Cajal (ICC) are pacemaker cells that generate spontaneous electrical slow waves, and mediate inputs from motor neurons in the gastrointestinal (GI) tract. Loss or defects in ICC networks are directly linked to GI motility disorders. Recent studies have demonstrated that ICC plays an important role in the development of diabetic gastroenteropathy (DGEP). Patients with DGEP show loss or defects in ICC networks that may lead to GI motility disorders. ICC express the receptor tyrosine kinase, KIT, which is the receptor for stem cell factor. KIT signaling is required for the normal development and maintenance of ICC in the GI tract. Therefore, it is possible that loss of ICC in DGEP may be a result of reduced expression of KIT. Recent studies show that expression of Kit is regulated by microRNAs (miRNAs). Thus, our central hypothesis is that miRNAs targeting Kit inhibit the development and maintenance of ICC in DGEP. To address the hypothesis, we propose the following specific aims: 1) Characterization of microRNAome in ICC, 2) Identification of changes in microRNAs during the development of DGEP, and 3) Suppression of the growth and maintenance of ICC by miRNAs targeting Kit. To achieve the specific aims, we will utilize two animal models Kit+/copGFP and type 2 diabetic Kit+/copGFP;Lepob/ob mutant mice that we have recently generated . Both mice express a bright green fluorescent protein copGFP in a Kit-specific manner, which offers a powerful new model to study the function and genetic regulation of ICC phenotypes. Completion of the specific aims of this project will provide information about the miRNAs expressed specifically by ICC and how this body of regulatory molecules is altered in a major GI motor disorder. Our preliminary data suggest that many of the miRNAs in ICC target Kit. This study will describe a novel molecular mechanism involving miRNAs that inhibit KIT expression. This is an exciting opportunity to understand how KIT expression in ICC is regulated and how ICC are lost during the development of DGEP. Identification of the miRNAs inhibiting KIT expression may aid in the development of a therapeutic antisense miRNA drug that might be useful in blocking or reversing damaged ICC networks in DGEP and other GI motility and functional disorders in which loss of ICC occurs. PUBLIC HEALTH RELEVANCE: Loss of interstitial cells of Cajal (ICC) is directly linked to diabetic gastroenteropathy (DGEP), but the molecular mechanism underlying the ICC disruption is elusive. The present study seeks to uncover a novel mechanism involving microRNAs that lead to the loss of ICC during the development of DGEP.