Rho-kinase signaling in energy balance

黑素皮质素信号通路已成为调节正常体重的关键信号系统。 动态平衡和能量平衡。-msh激活黑素皮质素-4受体减少脂肪储存 通过减少食物摄入量和增加能量消耗。然而，其背后的细胞机制(S) 黑素皮质素的作用仍然知之甚少。我们的初步数据表明了ROK1行动的重要性 在表达MC4R的神经元中，这对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Sim1的神经元中选择性缺失ROCK1显著增加机体 体重和肥胖。有趣的是，我们发现在含有MC4R的神经元中，ROCK1的激活是 黑素皮质素通过抑制AMPK的厌食作用。证据表明，UBE2O是一种 针对2AMPK泛素化和降解的AMPK上游介体。此外，我们观察到 来自巴基斯坦血缘人群的人类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是正常体重代谢调节所必需的 动态平衡和能量平衡，与UBE2O-AMPK信号级联起厌氧作用 黑色素皮质素。因此，ROCK1信号轴受损导致能量失衡，导致肥胖。对这件事 最后，我们将(I)阐明ROCK1在MC4R表达神经元中的功能重要性。 能量平衡；(Ii)建立ROCK1调节黑素皮质素摄食效应的机制(S)； 以及(3)探讨人类ROCK1突变(E942K)在调节能量平衡中的意义。至 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 生理技术，包括基因工程组织特异性转基因小鼠模型，突变 携带人类ROCK1-E942K突变、Cre诱导的AAV、DREADD和rAAV-Flexon开关的小鼠 系统。这些研究将提供一个独特的机会，以建立一个新的机制，牵连ROCK1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 对肥胖相关代谢性疾病发病机制的进一步认识和新的治疗目标 用于治疗肥胖症。

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.