Antibody Mediated Glomerular Injury

该提案的主要目标是探索Notch 4有助于成熟的完整性的假设。 足细胞这将通过分析抗体介导的足细胞的体外和体内模型来实现。 损伤和Notch 4缺陷（N4-/-）小鼠。我们发现Notch 4存在于成熟大鼠和小鼠的足细胞中， N4-/-小鼠足细胞局灶性消失，nephrin表达增加，聚集和移位。 此外，Notch 4表达丰富，总nephrin减少与大鼠蛋白尿的发生一致 被动Heymann肾炎，这表明Notch 4可能调节足细胞基因转录。因此，我们将 根据四个特定的目的来检查Notch 4在成熟足细胞中的作用。在第一个具体目标中，我们将使用 抗体和补体介导的细胞损伤的体外模型，以确定Notch 4是否被γ- 分泌酶和易位到细胞核结合和激活其核靶点，CSL。在第二个具体目标中， 随着时间的推移检查N4-/-小鼠，以确定Notch 4缺乏是否导致蛋白尿和足细胞的改变， 形态学和足细胞相关蛋白。第三个具体目标是确定Notch 4是否影响 对免疫性肾小球损伤的易感性和/或从免疫性肾小球损伤中恢复。N4+/+和N-/-同窝仔将使用各种方法进行研究。 抗体介导的足细胞损伤模型。他们对受伤的敏感性和恢复时间将受到监测， 将检测γ-分泌酶抑制的效果。第四个具体目标将利用一个比较 来自年轻雄性N4+/+和N-/-同窝仔的肾小球RNA的转录组分析， 抗体介导的足细胞损伤，以确定成熟肾小球中Notch 4调节的基因。差异表达 将检查基因在肾小球中的适当位置和表达以及Notch 4的调节。的结果 这些研究可能揭示了足细胞过早变性和肾小球硬化的潜在机制， 抗体介导的足细胞损伤患者的临床和病理学反应不同。

The primary goal of this proposal is to explore the hypothesis that Notch4 contributes to the integrity of the mature podocyte. This will be accomplished through an analysis of in vitro and in vivo models of antibody-mediated podocyte injury and Notch4-deficient (N4-/-) mice. We found that Notch4 is present in the podocytes of mature rats and mice and that the podocytes of N4-/- mice are focally effaced with increased expression, clustering and dislocation of nephrin. Moreover, Notch4 expression is abundant and total nephrin is reduced coincident with the onset of proteinuria in rats with passive Heymann nephritis, which suggests that Notch4 might regulate podocyte gene transcription. Thus, we will examine the role of Notch4 in the mature podocyte according to four specific aims. In the first specific aim we will use an in vitro model of antibody- and complement-mediated cell injury to determine if Notch4 is activated by gamma- secretase and translocates to the nucleus to bind and activate its nuclear target, CSL. In the second specific aim we will examine N4-/- mice over time to determine if Notch4 deficiency leads to proteinuria and alterations in podocyte morphology and podocyte-associated proteins. The third specific aim is to determine if Notch4 influences the susceptibility to and/or recovery from immune glomerular injury. N4+/+ and N-/- littermates will be studied using various models of antibody-mediated podocyte injury. Their susceptibility to injury and time to recovery will be monitored, and the effect of gamma-secretase inhibition will be examined. The fourth specific aim will utilize a comparative transcriptome analysis of glomerular RNA derived from young male N4+/+ and N-/- littermates before and after antibody-mediated podocyte injury to identify genes that Notch4 regulates in mature glomeruli. Differentially expressed genes will be examined for appropriate location and expression in glomeruli and regulation by Notch4. The results of these studies may disclose mechanisms underlying premature podocyte degeneration and glomerular sclerosis and the variable clinical and pathological response of patients with antibody-mediated podocyte injury.