HIF-1 AND HYPOXIC RESPONSE IN DEVELOPMENT AND DISEASE

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 低氧诱导因子(HIF)是一种转录因子，通过上调糖酵解酶和血管生成因子等基因，控制哺乳动物细胞对低氧压的转录反应。在正常氧压下，该途径受到翻译后蛋白酶体降解HIF-α亚基的负调控，该途径需要含有酶修饰的Pro-羟基酶结构域(PHD)，然后是von-Hippel Lindau(VHL)肿瘤抑制因子多泛素化(PVHL)。小鼠对HIF、pVHL、PHD和VEGF的敲除已经证明了这些低氧反应途径蛋白在发育过程中的重要作用。这些基因在广泛的组织中的条件性缺失进一步表明，该通路的消融或过表达在体内具有深远的影响，对生理学、病理学和肿瘤生物学具有重要的意义。尽管最近在了解细胞如何应对低氧分压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并不完全清楚。我们建议使用电子显微镜观察在常氧或低氧条件下体外培养的带有和不带有HIF-1α的原代小鼠T细胞。具体地说，我们想看看细胞器的形态(包括线粒体，HIF-1已经被证明是调节的)，以及核质比。我们认为，这一分析可能会产生新的令人兴奋的信息，即HIF-1如何在面临缺氧的情况下最大化细胞代谢效率。

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.