VEGF AND NEPHROVASCULAR DEVELOPMENT

血管的发育是肾脏的一件大事 然而，形态发生是肾血管化的分子基础， 不明可溶性血管生成因子的作用已被假定。 血管内皮生长因子（VEGF）是最好的候选人， 因为它是一种分泌的直接作用的内皮细胞， 血管生成所需的丝裂原。 有待检验的假设是：1）VEGF介导肾小球 缺氧调节VEGF介导的血管生成。 为了解决第一个问题，我们将定义VEGF对 肾器官培养，我们将使用VEGF鉴定VEGF靶细胞 FIK-1（+/-）转基因小鼠的受体抗体和β-gal染色 外植体为了验证第二个假设，培养的肾脏将被 暴露于缺氧和内皮细胞分化， 通过形态学研究评估增殖。VEGF作用 将使用抗VEGF中和抗体来定义介导这些事件 抗体的这些实验将使用胎鼠进行， FIK-1（+/-）转基因小鼠。我们将识别并克隆转录 缺氧时VEGF调控相关因子的表达 从缺氧肾脏构建的文库，用O2筛选 敏感的DNA探针和差异显示PCR扩增 来自缺氧和对照外植体的mRNA。 组织化学、分子生物学和转基因技术相结合 技术将使我们能够确定肾内皮细胞的起源， 细胞，并确定血管内皮生长因子在肾脏血管化的作用。 了解血管发生的分子机制， 血管生成应该产生新的预防，诊断， 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.