HOST FACTORS IN PATHOGENESIS OF HIV ASSOCIATED NEPHROPATHY

HIV-1相关性肾病(HIVAN)是一种由HIV-I直接感染肾小球和肾小管上皮细胞引起的疾病。作为这种感染的结果，足细胞和肾小管上皮细胞表现出各种表型变化，包括去分化、增殖增加和凋亡增加。我们已经发现了响应HIV-1感染的新的宿主途径，其中包括Podocan，一个富含亮氨酸的小重复蛋白家族的新成员和SideKey，一个在决定视网膜中光感受器细胞命运的基因。在目前的方案中，我们建议探索这两个基因在人类HIVAN和转基因小鼠模型中的表达。为了更好地 了解Podocan在体内的内源性功能及其在肾脏疾病中的潜在作用，我们将产生Podocan缺失的小鼠以及足细胞过表达的转基因小鼠。为了研究SideKick-1在HIVAN中的作用，我们还将在转基因小鼠的足细胞中过表达它。我们将利用体外实验定位诱导SideKick-1表达的HIV-1基因产物(S)，并在体外研究SideKick-1和SideKick-2在足细胞感染前后的功能。并且，我们将确定SideKick-1和2的细胞内结合伙伴。最后，我们建议表征 人肾小管上皮细胞对HIV-1感染的寡核苷酸表达芯片研究。这一方法将使我们能够在体外识别HIV-1感染肾小管上皮细胞后特定时间点差异表达的基因。在探索了HIV-1感染对上皮细胞增殖和凋亡的影响后，我们将定位负责诱导这些影响的HIV-1基因(S)。这些研究结合项目1中的信息，将阐明HIV-1在易感人群中引发肾脏疾病的机制，并应提供对疾病机制的洞察 黑人总体上的进步。

HIV-1 associated nephropathy (HIVAN) is a disease of the glomerular and tubular epithelium caused by direct infection of these cellular compartments by HIV-I. As a result of this infection, podocytes and tubular epithelial cells demonstrate a variety of phenotypic changes, including de-differentiation, increased proliferation, and increased apoptosis. We have identified novel host pathways responding to HIV-1 infection that include Podocan, a novel member of the small leucine-rich repeat protein family and Sidekick, a gene that is important in specifying photoreceptor cell fate in the retina. In the current proposal, we propose to explore the expression of these two genes in human HIVAN and in the transgenic mouse model. To better understand the role of Podocan's endogenous function in vivo and its potential role in renal disease, we will generate Podocan-null mice as well as podocyte over-expressing transgenic mice. To examine the role for Sidekick-1 in HIVAN, we will also overexpress it in podocytes of transgenic mice. Using in vitro assays, we will map the HIV-1 gene product(s) that are responsible for inducing Sidekick-1 expression and investigate the function of Sidekick-1 and 2 in podocytes before and after HIV-1 infection in vitro. And, we will determine the intracellular binding partners for Sidekick-1 and 2. Finally, we propose to characterize the response of human renal tubular epithelial cells to HIV-1 infection using oligonucleotide expression microarrays. This approach will permit us to identify genes that are differentially expressed at specific time points following infection of renal tubular epithelial cells by HIV-1 in vitro. After exploring the effect of HIV-1 infection on proliferation and apoptosis in epithelial cells, we will map the HIV-1 gene(s) responsible for inducing these effects. These studies combined with information from Project #1 will elucidate mechanisms by which HIV-1 induces renal disease in susceptible individuals and should provide insight into the mechanisms of disease progression in Blacks in general.