Cocaine and HIV Influence Mitochondrial Epigenetics in Astrocytic Networks

项目总结/摘要 星形胶质细胞是中枢神经系统能量储存、利用和代谢功能的主要调节者 系统（CNS）。滥用可卡因和艾滋病毒感染是扰乱大脑能量的重要危险因素 代谢和可卡因滥用与HIV-1感染和随后的发展密切相关。 艾滋病这项研究的目的是调查可卡因和艾滋病毒反式激活蛋白的作用 （HIV-Tat）对星形胶质细胞能量代谢和相关神经元损伤的影响。DNA甲基化改变 线粒体基因组中编码NADH脱氢酶（NDH-1）的区域 位移环（D环） ND 1-ND 6亚基通过调节能量的积累和利用，在能量的储存和利用中起着重要作用 脑代谢的来源，以保持中枢神经系统细胞的功能。因此，我们研究了可卡因的作用 和/或HIV-1感染对改变星形胶质细胞能量的线粒体表观遗传机制的影响 新陈代谢.此外，线粒体DNA甲基转移酶（mtDNMTs）在影响能量中的作用 星形胶质细胞的缺陷导致神经元损伤从未在可卡因的背景下阐明， 或HIV-Tat，或两者的组合。我们的初步研究表明，可卡因和/或HIV-1达特靶向DNMT 和mtDNMT（mtDNMT 1、mtDNMT 3A和mtDNMT 3B），伴随线粒体激活 过氧化物酶体增殖物激活受体γ辅激活因子1 α（PGC-1α）的生物发生， 调节线粒体DNA合成和控制能量代谢，影响神经可塑性和棘密度。我们因此 假设可卡因通过激活DNMT作为HIV-Tat神经发病机制中的辅助因子 在星形胶质细胞中的表达导致能量缺乏并影响DNA甲基化和线粒体 生物起源这些表观遗传机制是由 的 5-甲基胞嘧啶（5-mC）、5-羟甲基胞嘧啶（5 hmC） D-环调控区及其作用 和10 - 11易位（泰特）家族 双加氧酶 ，影响能量转移到神经元和神经可塑性失调， 和细胞生长。因此，在具体目标1A中，我们将审查可卡因是否与 HIV-Tat影响星形胶质细胞的能量功能障碍，并影响DNMT，mtDNMT和生物发生主导的能量 转移，在目的1B #中，我们提出确定对神经可塑性/轴突/树突形成和细胞的影响。 在原代神经元的生长，从而导致神经元死亡;具体目标#2，我们将验证 机制研究涉及可卡因暴露的HIV-Tat（GT-tg）转基因小鼠，以研究mtDNMT 在能量代谢中的作用，以及吡拉西坦（a 神经保护剂） 治疗可以逆转 可卡因和HIV-Tat对mtDNMT的作用导致神经可塑性和轴突/树突形成， 调节能量代谢影响神经毒性的治疗策略。对可卡因的了解， 导致神经毒性的HIV相关星形胶质细胞能量缺乏将对以下方面具有转化意义： 治疗靶向和控制艾滋病毒感染的可卡因使用者的能量代谢。

Project Summary/Abstract Astrocytes are the major regulators for energy storage, utilization and metabolic function in the central nervous system (CNS). Cocaine abuse and HIV infections are significant risk factors for disrupting brain energy metabolism and cocaine abuse is strongly associated with HIV-1 infection and a subsequent development of AIDS. The proposed research is aimed at investigating the effects of cocaine and HIV-Transactivator protein (HIV-Tat) on astrocyte energy metabolism and associated neuronal impairments. Altered DNA methylation in the region of the mitochondrial genome encoding the NADH dehydrogenase (NDH- displacement loop (D-loop) Family) subunits (ND1-ND6) plays a critical role in energy storage and utilization by regulating the energy source of brain metabolism to preserve CNS cell functions. Therefore, we investigated the role of cocaine and/or HIV-1 infection on the mitochondrial epigenetic mechanisms that alters the astrocytic energy metabolism. Moreover, the role of mitochondrial DNA methyl transferases (mtDNMTs) in impacting energy deficits in astrocytes leading to neuronal impairment has never been elucidated in the context of either cocaine or HIV-Tat, or in combination. Our preliminary studies showed that cocaine and/or HIV-1 Tat targets DNMTs and mtDNMTs (mtDNMT1, mtDNMT3A and mtDNMT3B) with concomitant activation of mitochondrial biogenesis in peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) that is known to regulate mtDNA synthesis and control energy metabolism affecting neuro plasticity and spine density. We thus hypothesize that cocaine acts as a co-factor in the neuropathogenesis of HIV-Tat by activating DNMTs expression in astrocytes leading to energy deficits and impacting DNA methylation and mitochondrial biogenesis. These epigenetic mechanisms are mediated by of 5-methylcytosine (5-mC), 5-hydroxymethylcytosine (5hmC) the regulatory D-loop region and its effect and ten-eleven translocation (TET) family dioxygenases , which affect energy transfer into neurons and dysregulate neuro plasticity, spine density and cell growth. Accordingly, in the specific Aim # 1A we will examine whether cocaine in association with HIV-Tat affect energy dysfunction of astrocytes and impacts DNMTs, mtDNMTs and biogenesis-led energy transfer, in Aim 1B# we propose to determine the effect on neuroplasticity/ axons/ dendrites formation and cell growth in primary neurons thereby contributing to neuronal death; the specific Aim # 2, we will validate the mechanistic study involving cocaine exposure of HIV-Tat (GT-tg) transgenic mice to investigate the mtDNMTs role in energy metabolism, and whether piracetam (a neuro-protective agent) treatment reverses the effects of cocaine and HIV-Tat on mtDNMTs leading to neuro plasticity and axons/ dendrites formation to develop a therapeutic strategy regulating energy metabolism impacting neurotoxicity. An understanding of cocaine and HIV-associated astrocytes energy deficits that lead to neurotoxicity will have translational significance for therapeutic targeting and controlling the energy metabolism in HIV-infected cocaine users.