Role of ABHD6 in 2-AG Signaling

描述（由申请人提供）：靶向脑中的内源性大麻素（eCB）信号传导的化合物代表了探测健康和患病脑中该信号传导系统的基本生物学功能的强大药理学工具，并且可以代表治疗神经系统疾病如亨廷顿病（HD）的新治疗途径。在该RO 1的资助周期中，我们的实验室研究了ABHD 6在神经元和神经胶质中的功能，以及ABHD 6抑制剂在R6/2小鼠（一种早发性HD小鼠模型）中的治疗潜力。我们利用功能蛋白质组学和shRNA技术，并确定ABHD 6作为脑中2-AG水解的候选酶。然后，我们开发了新的ABHD 6抑制剂，并表明ABHD 6活性严格控制大麻素受体2-AG的水平和功效。总之，这些研究表明ABHD 6属于eCB信号系统。最近，我们发现体内ABHD 6抑制大大降低了R6/2小鼠癫痫发作的发生率并减轻了海马神经病理学。在这项研究中，我们将测试以下假设：新型酶ABHD 6控制大麻素CB 1受体2-花生四烯酸甘油（2-AG）的水平和功效。ABHD 6抑制剂在两种HD小鼠模型（R6/2和HDQ 200）中降低癫痫发作活性，并可能代表一类新的治疗癫痫发作的药物。为了验证这一假设，我们提出了3个目标：目标1：开发、验证和第三代ABHD 6抑制剂的作用机制，这些抑制剂表现出上级的体内选择性和功效。目标2：确定在HD和化学诱导癫痫发作小鼠模型中ABHD 6体内抑制和基因缺失降低癫痫发作发生率的程度。 目的3：为什么HD小鼠癫痫发作，ABHD 6如何阻止这一过程？因此，我们将表征ABHD 6的新优化抑制剂，ABHD 6是我们在上一个资助期内鉴定的eCB水解酶。结合遗传学方法，我们将使用ABHD 6抑制剂来确定这种酶如何控制HD小鼠模型中癫痫发作发生率的分子和细胞细节。上述研究的完成将全面了解ABHD 6在癫痫活动背景下在健康和HD小鼠大脑中的作用。我们的长期目标是增加我们对ABHD 6在健康和患病大脑中所起作用的理解，并帮助开发新的治疗方法，这些治疗方法不存在滥用和经典大麻素激动剂产生不良反应的可能性。

DESCRIPTION (provided by applicant): Compounds that target endocannabinoid (eCB) signaling in the brain represent powerful pharmacological tools to probe the basic biological function of this signaling system in healthy and diseased brain and may represent novel therapeutic venues to treat neurological diseases such as Huntington's disease (HD). During the funding cycle of this RO1, our laboratory studied the function of ABHD6 in neurons and glia, as well as the therapeutic potential of ABHD6 inhibitors in R6/2 mice, an early-onset mouse model of HD. We leveraged functional proteomics and shRNA technology and identified ABHD6 as a candidate enzyme for 2-AG hydrolysis in brain. We then developed new ABHD6 inhibitors and showed that ABHD6 activity tightly controls the levels and efficacy of 2-AG at cannabinoid receptors. Together, these studies demonstrated that ABHD6 belongs to the eCB signaling system. Recently we found that in vivo ABHD6 inhibition greatly reduces seizure incidence and attenuates hippocampal neuropathology in R6/2 mice. In this grant, we will test the following hypothesis: The novel enzyme, ABHD6, controls both the level and efficacy of 2-arachidonoylglycerol (2-AG) at cannabinoid CB1 receptors. ABHD6 inhibitors reduce seizure activity in two HD mouse models (R6/2 and HDQ200) and may represent a novel class of therapeutics to treat seizures in general. To test this hypothesis, we propose 3 Aims: AIM 1: Development, validation, and mechanism of action of 3rd generation ABHD6 inhibitors that exhibit superior in vivo selectivity and efficacy. AIM 2: Determine to what extent ABHD6 in vivo inhibition and genetic deletion reduces seizure incidence in HD and chemically-induced seizures mouse models. AIM 3: Why do HD mice seize, and how does ABHD6 prevent this process? Thus we will characterize newly optimized inhibitors of ABHD6, an eCB-hydrolyzing enzyme that we identified during the previous funding period. Coupled to genetic approaches, we will use ABHD6 inhibitors to determine the molecular and cellular details of how this enzyme controls seizure incidence in HD mice models. Completion of the studies outlined above will provide a comprehensive understanding of the role of ABHD6 in healthy and HD mouse brain within the context of epileptic activity. Our long-term goal is to increase our understanding of th role played by ABHD6 in healthy and diseased brain, and help develop novel therapeutics that lack the potential for abuse and adverse effects produced by classic cannabinoid agonists.