Astrocyte-TAAR1 & METH in HAND

 描述(申请人提供)：作为一种流行的精神刺激剂，甲基苯丙胺(冰毒)的使用会导致持久的、强烈的愉悦效果。虽然冰毒滥用在普通人群中很常见，但大约10%-15%的人类免疫缺陷病毒1型(HIV-1)患者报告滥用冰毒。冰毒会加重HIV相关神经认知障碍(HAND)的严重程度和发病。甲基和手部神经发病机制都与神经炎症、星形胶质细胞激活、脑高温、氧化应激和兴奋性毒性有关。因此，冰毒影响了星形胶质细胞的多种功能，但实现这一功能的机制尚不清楚。最近，我们报道了示踪胺相关受体1(TAAR1)是一种新的星形胶质细胞甲基信号受体。在这项提案中，我们将研究冰毒介导的TAAR1的调节和激活，以及在冰毒共病的背景下导致手部疾病恶化的下游影响。我们在这项研究中的初步数据表明，pCREB在星形胶质细胞冰毒信号中起着关键作用。最近，TAAR1也成为一个很有前途的药物治疗靶点。我们认为手中的冰毒通过cAMP、[Ca~(2+)]i、PKA/ERK、PKC和NF-kB调节CREB来调节星形胶质细胞-TAAR1及其下游信号。这些通路在星形胶质细胞介导的神经毒性结果中起着关键的机制作用(S)，包括线粒体损伤、氧化应激、兴奋性毒性和神经炎症。此外，我们建议星形胶质细胞-TAAR1作为手部和冰毒共病的新的治疗靶点。我们将在目标1中对TAAR1的分子调控进行研究，在目标2中描绘改变星形胶质细胞功能的复杂的细胞内信号通路，最后在目标3中利用与手相关的动物模型将这项工作扩展到潜在的治疗途径。首先，我们将研究星形胶质细胞-TAAR1的调控以及导致胶质增生和神经炎症的cAMP变化(目标1：分子)。用病毒毒素激活的人类星形胶质细胞，或那些表达病毒蛋白的细胞，在没有/没有冰毒的情况下将被使用。TAAR1-GFP过表达模型将用于识别TAAR1特异的反应。接下来，我们将描绘导致冰毒共病的星形胶质细胞-TAAR1细胞内信号(目标2：信号与功能)。最后，我们将评估TAAR1作为一个潜在的治疗靶点(目标3：翻译)。综上所述，我们采用细胞和分子相结合的方法进行体外、体外和体内研究，这些研究将对星形胶质细胞-TAAR1的调节、其在药物滥用引起的神经缺陷中的作用以及作为治疗手部冰毒共病的新靶点具有更广泛的意义(S)。

 DESCRIPTION (provided by applicant): As a popular psychostimulant, methamphetamine (METH) use leads to long-lasting, strong euphoric effects. While METH abuse is common in the general population, approximately 10-15% of human immunodeficiency virus-1 (HIV-1) patients report METH abuse. METH exacerbates the severity and onset of HIV-associated neurocognitive disorders (HAND). Both METH and HAND neuropathogenesis mechanistically concur with neuroinflammation, astrocyte activation, brain hyperthermia, oxidative stress and excitotoxicity. Thus, METH affects a multitude of astrocyte functions, yet the mechanism through which this is attained is unclear. Recently, we reported trace amine associated receptor 1 (TAAR1) as a novel astrocyte receptor for METH signaling. In this proposal, we will investigate METH-mediated regulation and activation of TAAR1 and the downstream effects that lead to exacerbation of HAND in the context of METH comorbidity. Our preliminary data in this proposal suggest a critical role of pCREB in astrocyte-METH signaling. Recently, TAAR1 has also emerged as a promising pharmacotherapeutic target. We propose that METH-abuse in HAND modulates astrocyte-TAAR1 and downstream signaling via cAMP, [Ca2+]i, PKA/ERK, PKC and NF-kB regulating CREB. These pathways play critical mechanistic role(s) in astrocyte-mediated neurotoxic outcomes, including mitochondrial damage, oxidative stress, excitotoxicity and neuroinflammation. Further, we propose astrocyte-TAAR1 as a novel therapeutic target in HAND and METH comorbidity. We will conduct investigations in the molecular regulation of TAAR1 in Aim 1, delineate the complex intracellular signaling pathways altering astrocyte function in Aim 2 and lastly extend the work to potential therapeutic avenues using a HAND relevant animal model in Aim 3. First, we will investigate the regulation of astrocyte-TAAR1 and following cAMP changes leading to gliosis and neuroinflammation (Aim 1: Molecular). Human astrocytes activated with virotoxins, or those expressing viral proteins, with/out METH will be used. TAAR1-GFP overexpression model will be used to identify TAAR1-specific responses. Next, we will delineate astrocyte-TAAR1 intracellular signaling leading to METH comorbidity in HAND (Aim 2: Signaling and function). Lastly, we will evaluate TAAR1 as a potential therapeutic target (Aim 3: Translational). Taken together, we employ a combined cellular and molecular approach with ex vivo, in vitro and in vivo studies that will have broader implication(s) for astrocyte-TAAR1 regulation, its role in substance abuse-based neurological deficits and as a novel therapeutic target for METH comorbidity in HAND.