Targeting hypoxia-inducible mediators to manipulate human adipocyte phenotype

描述（由申请人提供）：肥胖与脂肪组织功能障碍状态相关，其特征在于炎症增加和代谢异常，这是全身性代谢疾病的基础。缺氧是肥胖症脂肪组织功能障碍的一个公认的根本原因。我们的初步数据表明，缺氧诱导炎症在人类脂肪组织巨噬细胞（ATM）和己糖胺生物合成（HBS）和脂肪生成在人类脂肪细胞，和内质网应激（ERS）和应激活化蛋白激酶（SAPK）调节这些过程。我们的长期目标是开发基于脂肪细胞和ATM基因修饰的代谢性疾病的新型细胞治疗。我们的具体目标是确定缺氧对人类脂肪细胞代谢和ATM炎症反应的影响，确定ERS和SAPK激活在调节这些过程中的作用，确定ATM在调节脂肪细胞代谢中的作用，最后，以确定是否对人脂肪细胞和ATM进行遗传修饰以实现HBS和SAPK的敲低-相关分子使脂肪细胞向有利的代谢表型转变。我们的主要假设是：低氧直接或通过低氧诱导的ATM炎症诱导代谢功能障碍，其特征在于脂肪细胞中脂肪生成和HBS增加;这些过程受ERS和SAPK活化调节;脂肪细胞中HBS相关介质和ATM中SAPK相关介质的遗传敲低将诱导脂肪细胞中有利的代谢表型。目的明确缺氧对人脂肪细胞ERS和代谢的调节作用，并确定抑制HBS是否减弱缺氧诱导的脂肪细胞ERS和代谢反应。目的二是明确缺氧在调节人ATM炎症反应中的作用，并确定SAPK介导的敲低是否减弱缺氧诱导的ATM炎症反应。目的III将明确缺氧启动的ATM在调节脂肪细胞代谢中的作用，并确定是否在ATM中敲低SAPK介导物减弱缺氧对脂肪细胞代谢的影响。这一建议是重要的，因为它将确定新的缺氧诱导介质和人体组织中脂肪组织功能障碍的机制，这将导致代谢疾病的治疗。该提议是创新的，因为它开发了用于人类脂肪细胞和ATM的遗传修饰的模型系统，其目标是操纵脂肪细胞朝向有利的代谢表型。

DESCRIPTION (provided by applicant): Obesity is associated with a state of adipose tissue dysfunction characterized by increased inflammation and aberrant metabolism that underlies systemic metabolic disease. Hypoxia is a putative root cause of adipose tissue dysfunction in obesity. Our preliminary data demonstrate that hypoxia induces inflammation in human adipose tissue macrophages (ATM) and hexosamine biosynthesis (HBS) and lipogenesis in human adipocytes, and that endoplasmic reticulum stress (ERS) and stress-activated protein kinases (SAPK) regulate these processes. Our long-term goal is to develop novel cell-based therapy for metabolic disease based on genetic modification of adipocytes and ATM. Our proposal-specific goals are to define the effects of hypoxia on human adipocyte metabolism and ATM inflammatory responses, to define the role of ERS and SAPK activation in regulating these processes, to define the role of ATM in regulating adipocyte metabolism, and finally, to determine if genetic modification of human adipocytes and ATM to accomplish knockdown of HBS and SAPK- related molecules shifts adipocytes towards a favorable metabolic phenotype. Our central hypotheses are: that hypoxia induces metabolic dysfunction characterized by increased lipogenesis and HBS in adipocytes, directly as well as via hypoxia-induced ATM inflammation; that these processes are regulated by ERS and SAPK activation; and that genetic knockdown of HBS-related mediators in adipocytes and SAPK-related mediators in ATM will induce a favorable metabolic phenotype in adipocytes. Aim I will define the role of hypoxia in regulating ERS and metabolism in human adipocytes and determine if inhibition of HBS attenuates hypoxia- induced ERS and metabolic responses in adipocytes. Aim II will define the role of hypoxia in regulating human ATM inflammation and determine if SAPK mediator knockdown attenuates hypoxia-induced ATM inflammatory responses. Aim III will define the role of hypoxia-primed ATM in regulating adipocyte metabolism and determine if SAPK mediator knockdown in ATM attenuates hypoxia's effects on adipocyte metabolism. This proposal is significant because it will identify novel hypoxia-inducible mediators and mechanisms of adipose tissue dysfunction in human tissues that will lead to therapy for metabolic disease. This proposal is innovative because it develops a model system for genetic modification of human adipocytes and ATM with the goal of manipulating adipocytes towards a favorable metabolic phenotype.