Mechanisms involved in podocyte damage in Alport Syndrome

在大多数慢性肾脏疾病（CKD）的进展过程中，足细胞丢失，肾小球损伤。 内皮细胞，肾小球基底膜（GBM）组成的变化导致 肾小球滤过屏障的结构和功能改变。了解机制 可能为发现新的途径铺平道路， 可以有针对性地减缓肾脏疾病的进展或可能逆转它。 本提案中提出的数据，使用芯片平台上的肾小球和FUCCI小鼠模型， 体内细胞周期变化的跟踪显示，足细胞与其GBM的结合发生改变，它们退出 在Alport综合征（AS）小鼠（我们的CKD模型）中， 其特征在于有缺陷的GBM。我们有证据表明，miR-193 a在小鼠中特异性上调， 人AS足细胞及其抑制有利于足细胞存活并调节足细胞与 他们的GBM。根据我们的数据，我们假设通过调节肾小球功能， 负责足细胞存活的重要分子途径可防止进一步损伤， 减缓肾脏疾病进展。 我们将使用多个转基因AS FUCCI小鼠和体外人类系统，研究其分子机制。 调节足细胞周期及其与有缺陷的GBM（典型的AS）的相互作用。具体而言，在Aim 我们将在体外研究miR-193 a的调节如何“重新编程”影响细胞信号传导网络。 足细胞生物学在目标2中，我们将进行体内研究以确定miR-193 a抑制剂的治疗效果。 作为基于肽两亲物胶束纳米颗粒的创新递送载体的货物递送 专门针对我们AS集落中的足细胞设计的。成功完成此提案将提供 对维持肾小球结构和功能的关键因素的新见解。重要的是这 知识可能适用于其他形式的CKD，并可能有助于发现新的 特别定制的治疗剂以维持足细胞存活并使肾小球损伤最小化。

During the progression of most chronic kidney diseases (CKD) podocytes are lost, and injury to glomerular endothelial cells, and changes in the composition of the glomerular basement membrane (GBM) lead to alterations of the structure and function of the glomerular filtration barrier. Understanding the mechanisms that induce glomerular cell damage could possibly pave the way to the discovery of new pathways that can be targeted to slow kidney disease progression or possibly reverse it. Data presented in this proposal, using the glomerulus on a chip platform and the FUCCI mouse model that allows tracking of the cell cycle changes in vivo, show that podocytes present an altered binding to their GBM, they exit their quiescent state, and are lost during disease progression in Alport Syndrome (AS) mice, our model of CKD characterized by a defective GBM. We have evidence that miR-193a is upregulated specifically in mouse and human AS podocytes and that its inhibition favors podocyte survival and modulate podocyte interactions with their GBM. Based on our data, we hypothesize that re-establishing glomerular function by modulating important molecular pathways that are responsible for podocyte survival prevents further injury, thus slowing kidney disease progression. Using multiple transgenic AS FUCCI mice and in vitro human systems, we will study the molecular mechanisms that regulate the podocyte cell cycle and their interaction with a defective GBM, typical of AS. Specifically, in Aim 1 we will study in vitro how modulation of miR-193a can “re-program” cellular signaling networks that influence podocyte biology. In Aim 2 we will perform in vivo studies to determine the therapeutic effect of miR-193a inhibitor delivered as cargo of an innovative delivery vehicle based on peptide amphiphile micelle nanoparticles specifically designed to target podocytes in our AS colonies. Successful completion of this proposal will provide novel insights into key factors critical for maintenance of glomerular structure and function. Importantly, this knowledge would likely be applicable to other forms of CKD and possibly facilitate the discovery of new therapeutic agents tailored specifically to sustain podocyte survival and minimize glomerular damage.