Role of ABHD6 in 2-AG Signaling

描述（由申请人提供）：针对大脑内源性大麻素（eCB）信号的化合物是探索健康和患病大脑中该信号系统基本生物学功能的强大药理学工具，可能代表治疗神经系统疾病（如亨廷顿病（HD））的新治疗场所。在本RO1的资助周期中，我们实验室研究了ABHD6在神经元和胶质细胞中的功能，以及ABHD6抑制剂在早发性HD小鼠模型R6/2小鼠中的治疗潜力。我们利用功能蛋白质组学和shRNA技术鉴定了ABHD6作为脑中2-AG水解的候选酶。然后，我们开发了新的ABHD6抑制剂，并表明ABHD6活性严格控制大麻素受体上2-AG的水平和功效。总之，这些研究表明ABHD6属于eCB信号系统。最近，我们发现体内抑制ABHD6可大大降低R6/2小鼠癫痫发作发生率，减轻海马神经病理。在这项资助中，我们将测试以下假设：新型酶ABHD6控制大麻素CB1受体上2-花生四烯醇甘油酯（2-AG）的水平和功效。在两种HD小鼠模型（R6/2和HDQ200）中，ABHD6抑制剂可降低癫痫发作活动，可能代表了一类治疗癫痫发作的新疗法。为了验证这一假设，我们提出了3个目标：目标1：第三代ABHD6抑制剂的开发、验证和作用机制，该抑制剂具有卓越的体内选择性和有效性。目的2：确定ABHD6体内抑制和基因缺失在多大程度上降低HD和化学诱导癫痫小鼠模型中癫痫发作的发生率。AIM 3：为什么HD小鼠会癫痫发作？ ABHD6如何阻止这一过程？因此，我们将对新优化的ABHD6抑制剂进行表征，ABHD6是我们在上一个资助期内发现的一种eb水解酶。结合遗传学方法，我们将使用ABHD6抑制剂来确定这种酶如何控制HD小鼠模型中癫痫发作的分子和细胞细节。上述研究的完成将全面了解ABHD6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ABHD6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，这些治疗方法缺乏传统大麻素激动剂滥用和不良反应的可能性。

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.