VEGF AND NEPHROVASCULAR DEVELOPMENT

血管的发育是肾脏的一件大事 然而，形态发生是肾血管形成的分子基础 是未知的。已经推测了可溶性血管生成因子的作用。 血管内皮细胞生长因子(VEGF)是最好的候选因子 这样的作用是因为它是一种分泌的直接作用的内皮细胞 血管生成所需的有丝分裂原。 需要检验的假设是：1)血管内皮生长因子介导肾小球 血管生成；2)缺氧调节血管内皮生长因子介导的血管生成。 为了回答第一个问题，我们将定义血管内皮生长因子对 肾器官培养，用血管内皮生长因子鉴定血管内皮生长因子靶细胞 FIK-1(+/-)转基因的受体抗体和β-半乳糖染色 外植体。为了检验第二个假设，培养的肾脏将是 暴露在低氧和内皮细胞分化和 增殖情况将通过形态学研究进行评估。血管内皮生长因子作用 调解这些事件将使用抗血管内皮细胞生长因子中和来定义 抗体。这些实验将使用胎鼠和 FIK-1(+/-)转基因小鼠。我们将鉴定和克隆转录 低氧表达调控血管内皮生长因子的研究 从低氧肾脏特别构建的文库，用O2筛选 灵敏DNA探针与差异显示聚合酶链式反应 低氧外植体和对照外植体的mRNAs。 组织化学、分子生物学与转基因的结合 技术将使我们能够确定肾内皮细胞的来源 并明确血管内皮生长因子在肾血管形成中的作用。 了解调控血管生成的分子机制和 血管生成应产生新的预防、诊断策略 以及治疗肾血管疾病和癌症。

The development of blood vessels is a major event in kidney morphogenesis, however, the molecular basis of kidney vascularization is unknown. A role for soluble angiogenic factors has been postulated.. Vascular endothelial growth factor (VEGF) is the best candidate for such a role because it is a secreted direct acting endothelial cell mitogen required for vasculogenesis. The hypotheses to be tested are: 1) VEGF mediates glomerular vascularization, and 2) hypoxia regulates VEGF-mediated angiogenesis. To address the first question, we will define the effect of VEGF on kidney organ culture and we will identify VEGF target cells using VEGF receptors antibodies and beta-gal staining of FIK-1(+/-) transgenic explants. To test the second hypothesis, cultured kidneys will be exposed to hypoxia and endothelial cell differentiation and proliferation will be assessed by morphologic studies. VEGF role mediating these events will be defined using anti-VEGF neutralizing antibodies. These experiments will be performed using fetal rats and FIK-1(+/-)transgenic mice. We will identify and clone transcription factors involved in VEGF regulation by hypoxia using an expression library constructed ad hoc from hypoxic kidneys, screened with O2 sensitive DNA probes and differential display PCR amplification of mRNAs from hypoxic and control explants. The combination of histochemical, molecular biology and transgenic technology will enable us to determine the origin of renal endothelial cells and to define the role of VEGF in kidney vascularization. Understanding the molecular mechanisms governing vasculogenesis and angiogenesis should generate new strategies for prevention, diagnosis and treatment of renovascular disease and cancer.