ROCK1 Signaling in Glucose Metabolism

葡萄糖代谢中的 ROCK1 信号传导

• 批准号: 8235957
• 负责人: YOUNG-BUM KIM
• 金额: $ 37.47万
• 依托单位: BETH ISRAEL DEACONESS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-03-01 至 2015-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8235957
• 关键词: Ablation; Actins; Adenoviruses; Adipocytes; Adipose tissue; Affect; Biochemical; Biological Process; Breeding; Cell Line; Cells; Data; Diabetes Mellitus; Diabetic mouse; Gene Targeting; Gene Transfer; Goals; Grant; Human; Insulin; Insulin Resistance; Lead; Mediating; Mediator of activation protein; Metabolic; Metabolism; Molecular; Mus; Muscle; Muscle Cells; Non-Insulin-Dependent Diabetes Mellitus; Obesity; Pathogenesis; Pathway interactions; Pharmaceutical Preparations; Phosphorylation; Protein Isoforms; RNA Interference; ROCK1 gene; Regulation; Rho-associated kinase; Risk Factors; Role; Serine; Signal Transduction; Skeletal Muscle; Small RNA; Tissues; Work; adiponectin; base; blood glucose regulation; glucose metabolism; glucose tolerance; glucose transport; glucose uptake; in vivo; insulin sensitivity; insulin signaling; mutant; novel; prevent; public health relevance; recombinase; research study; response

DESCRIPTION (provided by applicant): We have identified Rho-Kinase (ROCK) as a novel regulator of insulin action and glucose homeostasis. Specifically, ROCK directly regulates IRS-1 function by phosphorylating serine residues. Inhibition of ROCK function results in a reduction of insulin-stimulated glucose transport and insulin signaling, leading to insulin resistance. We found that ROCK1 deficiency causes systemic insulin resistance in vivo by impairing insulin signaling in skeletal muscle. Furthermore, insulin-stimulated ROCK activity is decreased in the skeletal muscle of obese diabetic mice and humans, suggesting that defective ROCK activity may contribute to the pathogenesis of insulin resistance. We thus hypothesize that activation of ROCK1 is critical for the metabolic action of insulin on glucose transport and insulin signaling through IRS-1 serine phosphorylation. The overall objective of this proposal is to define the novel role of ROCK1 in the regulation of glucose metabolism and insulin signaling. Aim 1 works to determine the role of IRS-1 serine phosphorylation in ROCK1-dependent glucose metabolism. We will systemically investigate how ROCK1 controls insulin- mediated glucose metabolism via affecting IRS-1 serine phosphorylation. This will be achieved by reintroducing IRS-1 mutants in IRS-1-deficient cells and mice. Aim 2 further elucidates the molecular mechanism in which ROCK1 is a key regulator of insulin action on glucose transport and downstream signaling. We will use small RNA interference and adenovirus gene-transfer strategies to determine the fundamental basis underlying insulin-induced activation of ROCK1 in insulin-sensitive cells or specific cell lines in which ROCK1 or IRS-1 has been deleted. Aim 3 defines the role of ROCK1 in whole-body glucose homeostasis and insulin sensitivity in insulin-target tissues. We have successfully generated loxP flanked ROCK1 mice, which are currently being breed with mice expressing MCK-Cre or adiponectin-Cre recombinase producing muscle- or adipose-specific ROCK1-deficient mice. These mice will be characterized for whole-body insulin sensitivity and glucose homeostasis, with important implications for strategies to prevent diabetes. These studies provide a unique opportunity to identify a novel molecular mechanism in which ROCK1 is important as a critical node in insulin control of metabolism, and may offer a novel target for the treatment of diabetes and obesity. PUBLIC HEALTH RELEVANCE: Insulin resistance is a major risk factor for type 2 diabetes, and the cause of this is not fully understood. Preliminary data show that the inhibition of the ROCK1 function results in a decreased insulin response, leading to insulin resistance. The goal of the study is to determine the biological function of ROCK1 in insulin control of glucose metabolism, and these experiments could lead to the identification of a potential target for new diabetes drugs.

描述（由申请人提供）：我们已确定 Rho 激酶 (ROCK) 是胰岛素作用和葡萄糖稳态的新型调节剂。具体来说，ROCK 通过磷酸化丝氨酸残基直接调节 IRS-1 功能。 ROCK 功能的抑制会导致胰岛素刺激的葡萄糖转运和胰岛素信号传导减少，从而导致胰岛素抵抗。我们发现 ROCK1 缺陷通过损害骨骼肌中的胰岛素信号传导而导致体内全身性胰岛素抵抗。此外，肥胖糖尿病小鼠和人类骨骼肌中胰岛素刺激的 ROCK 活性降低，表明 ROCK 活性缺陷可能导致胰岛素抵抗的发病机制。因此，我们假设 ROCK1 的激活对于胰岛素对葡萄糖转运的代谢作用以及通过 IRS-1 丝氨酸磷酸化的胰岛素信号传导至关重要。该提案的总体目标是确定 ROCK1 在葡萄糖代谢和胰岛素信号传导调节中的新作用。目标 1 致力于确定 IRS-1 丝氨酸磷酸化在 ROCK1 依赖性葡萄糖代谢中的作用。我们将系统地研究 ROCK1 如何通过影响 IRS-1 丝氨酸磷酸化来控制胰岛素介导的葡萄糖代谢。这将通过在 IRS-1 缺陷细胞和小鼠中重新引入 IRS-1 突变体来实现。目标 2 进一步阐明了 ROCK1 是胰岛素对葡萄糖转运和下游信号传导作用的关键调节因子的分子机制。我们将使用小RNA干扰和腺病毒基因转移策略来确定胰岛素敏感细胞或ROCK1或IRS-1已被删除的特定细胞系中胰岛素诱导的ROCK1激活的基本原理。目标 3 定义了 ROCK1 在胰岛素靶组织的全身葡萄糖稳态和胰岛素敏感性中的作用。我们已经成功生成了 loxP 侧翼 ROCK1 小鼠，目前正在与表达 MCK-Cre 或脂联素-Cre 重组酶的小鼠进行繁殖，产生肌肉或脂肪特异性 ROCK1 缺陷小鼠。这些小鼠将具有全身胰岛素敏感性和葡萄糖稳态的特征，这对预防糖尿病的策略具有重要意义。这些研究提供了一个独特的机会来确定一种新的分子机制，其中ROCK1作为胰岛素控制代谢的关键节点非常重要，并且可能为治疗糖尿病和肥胖症提供新的靶点。 公共卫生相关性：胰岛素抵抗是 2 型糖尿病的主要危险因素，其原因尚不完全清楚。初步数据显示，ROCK1功能的抑制会导致胰岛素反应降低，从而导致胰岛素抵抗。该研究的目的是确定 ROCK1 在胰岛素控制葡萄糖代谢中的生物学功能，这些实验可能有助于确定新的糖尿病药物的潜在靶点。