Rho-kinase signaling in energy balance

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。黑素皮质素-4受体（MC 4 R）的激活MSH减少脂肪储存 通过减少食物摄入和增加能量消耗。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ROCK 1作用的重要性 在表达MC 4 R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MC 4 R或Sim 1的神经元中选择性缺失ROCK 1显著增加了身体的运动能力， 体重和肥胖。有趣的是，我们发现，ROCK 1激活MC 4 R神经元是必需的， 黑皮质素通过抑制AMPK的促凋亡作用。有证据表明，UBE 2 O是一种 目标是AMPK的上游介体？2AMPK用于泛素化和降解。此外，我们观察到 来自巴基斯坦近亲人群的人ROCK 1变体（2824 G <A，E942 K）显示严重的 携带人ROCK 1突变（E942 K）的突变小鼠肥胖。因此我们假设 表达MC 4 R的神经元中的ROCK 1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UBE 2 O-AMPK信号级联反应有关，以发挥促凋亡作用 黑皮质素因此，ROCK 1信号轴受损导致能量失衡，导致肥胖。本 最后，我们将（i）阐明ROCK 1在MC 4 R表达神经元中的功能重要性， （ii）建立ROCK 1介导黑皮质素对进食的影响的机制; （iii）探讨人类ROCK 1突变（E942 K）在调节能量平衡中的意义。到 为了实现这些目标，我们将采用最先进的生物化学、分子、细胞和代谢 生理技术，包括基因工程组织特异性转基因小鼠模型，突变体 携带人ROCK 1-E942 K突变、Cre诱导型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，涉及ROCK 1作为 下丘脑能量平衡的关键决定因素从这些及时的研究中产生的数据可以提供 进一步深入了解肥胖相关代谢疾病的发病机制，并找到新的治疗靶点 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.