HIF-1 AND HYPOXIC RESPONSE IN DEVELOPMENT AND DISEASE

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 中心，不一定是研究者的机构。 低氧诱导因子（HIF）是一种转录因子，其通过上调包括糖酵解酶和血管生成因子（如血管内皮生长因子（VEGF））的基因来控制哺乳动物细胞对低氧张力的转录响应。在正常氧张力下，该途径受HIF-α亚基的翻译后蛋白酶体降解的负调控，该途径需要含有脯氨酰羟化酶结构域（PHD）的酶修饰，然后是von-Hippel Lindau（VHL）肿瘤抑制因子聚泛素化（pVHL）。小鼠HIF、pVHL、PHD和VEGF的敲除已经证明了这些缺氧反应途径蛋白在发育中的重要作用。这些基因在广泛组织中的条件性缺失进一步表明，该途径的消融或过表达具有深刻的体内效应，对生理学、病理学和肿瘤生物学具有重要意义。尽管最近在理解细胞如何响应低氧张力方面取得了这些进展，但HIF-1对线粒体和整个细胞的调节作用尚未完全理解。我们建议使用电子显微镜观察原代小鼠T细胞与HIF-1 α，已在体外培养的常氧或缺氧条件下。具体来说，我们想看看细胞器形态（包括线粒体，其中HIF-1已被证明是调节），核质比。我们认为这项分析可能会产生新的和令人兴奋的信息，即HIF-1如何在缺氧时最大限度地提高细胞代谢效率。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The hypoxia-inducible factor (HIF) is a transcription factor that controls the mammalian cellular transcriptional response to low oxygen tension by up-regulating genes including glycolytic enzymes and angiogenic factors, such as the vascular endothelial growth factor (VEGF). Under normal oxygen tensions, the pathway is negatively regulated by posttranslational proteasomal degradation of HIF-alpha subunits in a pathway requiring prolyl-hydroxylase domain (PHD) containing enzyme modification followed by von-Hippel Lindau (VHL) tumor suppressor polyubiquitination (pVHL). Murine knockouts of HIF, pVHL, PHD, and VEGF have demonstrated the essential role of these hypoxic response pathway proteins in development. Conditional deletion of these genes in a wide range of tissues has further shown that ablation or overexpression of the pathway has profound in vivo effects, with important implications for physiology, pathology, and tumor biology. Despite these recent advances in the understanding of how cells respond to low oxygen tension, the modulatory effect of HIF-1 on mitochondria and on cells as a whole is not fully understood. We propose using electron microscopy to look at primary murine T cells with and without HIF-1 alpha which have been cultured in vitro in normoxic or hypoxic conditions. Specifically, we would like to look at organelle morphology (including mitochondria, which HIF-1 has been shown to modulate), and nuclear to cytoplasmic ratio. We feel this analysis may yield new and exciting information on how HIF-1 maximizes cellular metabolic efficiency in the face of oxygen deficit.