Rho-kinase signaling in energy balance

能量平衡中的 Rho 激酶信号传导

• 批准号: 10529777
• 负责人: YOUNG-BUM KIM
• 金额: $ 56.4万
• 依托单位: BETH ISRAEL DEACONESS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-05 至 2026-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10529777
• 关键词: Biochemical; Body Weight; Cardiovascular Diseases; Chronic Disease; Data; Desire for food; Eating; Energy Metabolism; Fatty acid glycerol esters; GH1 gene; GTP-Binding Protein alpha Subunits, Gs; Genetic Engineering; Goals; Homeostasis; Human; Hypothalamic structure; Impairment; Lead; Link; MSH receptor; Malignant Neoplasms; Mediating; Mediator of activation protein; Melanocortin 4 Receptor; Metabolic; Metabolic Diseases; Molecular; Morbid Obesity; Mus; Mutant Strains Mice; Mutation; Neurons; Non-Insulin-Dependent Diabetes Mellitus; Obesity; Pakistan; Pathogenesis; Physiological; Population; ROCK1 gene; Recombinant adeno-associated virus (rAAV); Regulation; Rho-associated kinase; Risk Factors; Signal Pathway; Signal Transduction; System; Techniques; Time; Tissue Engineering; Transgenic Mice; Ubiquitination; Variant; Weight Gain; designer receptors exclusively activated by designer drugs; energy balance; experimental study; feeding; insight; mouse model; new therapeutic target; novel; obesity development; obesity treatment

The melanocortin signaling pathway has emerged as a key signaling system regulating normal body-weight homeostasis and energy balance. Activation of melanocortin-4 receptor (MC4R) by -MSH reduces fat stores by decreasing food intake and increasing energy expenditure. Yet, the cellular mechanism(s) underlying melanocortin actions remains poorly understood. Our preliminary data point to the importance of ROCK1 action in MC4R-expressing neurons that is significant for the development of obesity in mice and humans. We found that selective deletion of ROCK1 in MC4R-expressing or Sim1-expressing neurons significantly increases body weight and adiposity. Interestingly, we found that ROCK1 activation in MC4R-containing neurons is required for the anorexigenic action of melanocortin through suppressing AMPK. Evidence demonstrates that UBE2O is an upstream mediator of AMPK that targets 2AMPK for ubiquitination and degradation. Furthermore, we observed that human ROCK1 variant (2824G<A, E942K) from a consanguineous population in Pakistan displays severe obesity, and the mutant mice carrying the human ROCK1 mutation (E942K) are obese. We therefore hypothesize that ROCK1 in MC4R-expressing neurons is necessary for the metabolic regulation of normal body-weight homeostasis and energy balance and is linked with the UBE2O-AMPK signaling cascade for anorexigenic action of melanocortin. Thus, an impaired ROCK1 signaling axis leads to energy imbalance, causing obesity. To this end, we will (i) elucidate the functional importance of ROCK1 in MC4R-expressing neurons in the control of energy balance; (ii) establish the mechanism(s) by which ROCK1 mediates the effect of melanocortin on feeding; and (iii) explore the significance of the human ROCK1 mutation (E942K) in regulating energy balance. To accomplish these goals, we will employ state-of-the-art biochemical, molecular, cellular, and metabolic physiological techniques, including genetically engineered tissue-specific transgenic mouse models, mutant mice carrying the human ROCK1-E942K mutation, Cre-inducible AAV, DREADD, and the rAAV-FlexON switch system. These studies will provide a unique opportunity to establish a novel mechanism implicating ROCK1 as a key determinant of hypothalamic energy balance. The data generated from these timely studies may offer further insights into the pathogenesis of obesity-linked metabolic diseases and lead to new therapeutic targets for the treatment of obesity.

黑皮质素信号通路已成为调节正常体重的关键信号系统 体内平衡和能量平衡。 α-MSH 激活黑皮质素 4 受体 (MC4R) 可减少脂肪储存 通过减少食物摄入量和增加能量消耗。然而，潜在的细胞机制 黑皮质素的作用仍然知之甚少。我们的初步数据表明了 ROCK1 行动的重要性 在表达 MC4R 的神经元中，这对于小鼠和人类肥胖的发展具有重要意义。我们发现 在表达 MC4R 或表达 Sim1 的神经元中选择性删除 ROCK1 会显着增加身体 体重和肥胖。有趣的是，我们发现含有 MC4R 的神经元中的 ROCK1 激活是 黑皮质素通过抑制 AMPK 发挥食欲抑制作用。有证据表明 UBE2O 是 AMPK 的上游介体，以 α2AMPK 为目标进行泛素化和降解。此外，我们观察到 来自巴基斯坦近亲人群的人类 ROCK1 变异（2824G<A，E942K）表现出严重的 肥胖，携带人类ROCK1突变（E942K）的突变小鼠肥胖。因此我们假设 MC4R表达神经元中的ROCK1对于正常体重的代谢调节是必需的 体内平衡和能量平衡，并与 UBE2O-AMPK 信号级联反应相关，具有抑制食欲的作用 黑皮质素。因此，ROCK1 信号轴受损会导致能量失衡，导致肥胖。对此 最后，我们将 (i) 阐明 ROCK1 在表达 MC4R 的神经元中控制 能量平衡； (ii) 建立 ROCK1 介导黑皮质素对进食的影响的机制； (iii) 探索人类 ROCK1 突变 (E942K) 在调节能量平衡中的重要性。到 为了实现这些目标，我们将采用最先进的生化、分子、细胞和代谢技术 生理学技术，包括基因工程组织特异性转基因小鼠模型、突变体 携带人类 ROCK1-E942K 突变、Cre 诱导型 AAV、DREADD 和 rAAV-FlexON 开关的小鼠 系统。这些研究将为建立一种新的机制提供一个独特的机会，该机制涉及 ROCK1 作为 下丘脑能量平衡的关键决定因素。这些及时研究产生的数据可能会提供 进一步了解肥胖相关代谢疾病的发病机制并产生新的治疗靶点 用于治疗肥胖症。