Investigating Parkin-mediated Neuronal Energy Maintenance in Methamphetamine Use Disorder

项目总结/摘要 在我国阿片类药物危机最严重的时候，甲基苯丙胺（METH）过量死亡的人数在 没有FDA批准的药物用于METH使用障碍（MUD）。需要新的药物靶点， 特别是对于那些大量使用这种药物的人，因为他们最难戒断METH， 这些人有各种严重的神经系统问题，并且有服用过量药物的高风险。我们对老鼠的研究 重度强迫性METH消耗（重度MUD）模型提供了证据， 位于脑桥核（NAc）的神经保护蛋白parkin是一个关键的奖赏介导脑区， 在严重的泥。Parkin是一种蛋白质-泛素连接酶，已知在维持线粒体健康方面发挥关键作用 因此，在维持细胞能量-三磷酸腺苷（ATP）的产生。我们的初步 蛋白质组学数据显示，NAc中parkin的上调导致几个Krebs循环的上调， 而parkin敲除导致它们的下调。功能失调的线粒体 使用METH的后果。该提案调查了帕金减少甲基的新假设 渴望和成瘾行为的克雷布斯循环功能的NAc从甲基神经毒性。这 有助于维持暴露于METH的NAc神经元中ATP的产生，否则这将被METH损害。 诱导氧化应激。换句话说，我们将测试功能失调的线粒体是否是MUD的原因。 我们将通过三个独立的具体目标来检验这一假设。具体目标1将确定， parkin如何保护大鼠NAc中的Krebs循环功能免受自我施用METH的神经毒性。具体 目的2将确定是否在患有严重MUD的大鼠NAc中parkin过表达会减少 METH成瘾行为。具体目标3将确定是否过度氧化应激- 敏感的Krebs循环酶DLST（二氢硫辛酰胺S-琥珀酰转移酶）在大鼠NAc中的作用 严重的MUD会减少METH成瘾行为。假设帕金可以起到双重作用， METH神经毒性和METH渴望，这些研究将确定是否针对帕金有显着的 治疗重度MUD的潜力。鉴于有限的间接数据表明，NAc中的METH神经毒性 线粒体有助于MUD的发展，这些研究将澄清METH的作用， 诱导氧化应激介导METH的使用和发展的动机，寻求METH期间 禁欲此外，这些结果将有利于阿片类药物和酒精使用障碍的研究，因为这些障碍 引起线粒体功能障碍。最后，由于长期使用甲基苯丙胺，特别是高剂量使用甲基苯丙胺， 帕金森病的发展，也可能是阿尔茨海默病，这项研究的结果 将为这些研究领域添加信息。

PROJECT SUMMARY / ABSTRACT In the height of the opioid crisis in our country, deaths from methamphetamine (METH) overdose are on the rise, and there is no FDA-approved medication for METH use disorder (MUD). New drug targets are needed, particularly for people who heavily use the drug because they have the most difficulty quitting METH use, suffer from a variety of serious neurological problems, and are at high risk to overdose on the drug. Our work with a rat model of heavy compulsive METH consumption (severe MUD) provided evidence that overexpression of neuroprotective protein parkin in the nucleus accumbens (NAc), a key reward-mediating brain area, plays a role in severe MUD. Parkin is a protein-ubiquitin ligase known to play a critical role in maintaining mitochondrial health and, therefore, in maintaining generation of cellular energy - adenosine triphosphate (ATP). Our preliminary proteomic data shows that upregulation of parkin in the NAc leads to upregulation of several Krebs cycle enzymes whereas parkin knockout leads to their downregulation. Dysfunctional mitochondria are the known consequence of METH use. This proposal investigates the novel hypothesis that parkin decreases METH cravings and addictive behaviors by the Krebs cycle function in the NAc from METH neurotoxicity. This helps to maintain ATP generation in METH-exposed NAc neurons, which otherwise would be impaired by METH- induced oxidative stress. In other words, we will test whether dysfunctional mitochondria are a cause of MUD. We will test the hypothesis by three independent specific aims. The specific aim 1 will establish whether and how parkin protects Krebs cycle function in rat NAc from neurotoxicity of self-administered METH. The specific aim 2 will determine whether parkin overexpression in the NAc of rats with developed severe MUD will decrease METH addictive behaviors. The specific aim 3 will determine whether overexpression of oxidative stress- sensitive Krebs cycle enzyme DLST (dihydrolipoamide S-succinyl-transferase) in the NAc of rats with developed severe MUD will decrease METH addictive behaviors. Given that parkin may serve a dual function of decreasing METH neurotoxicity and METH cravings, these studies will determine whether targeting parkin has a significant therapeutic potential in severe MUD. Given the limited indirect data suggesting that METH neurotoxicity in NAc mitochondria contributes to development of MUD, these studies will provide clarity about the role of METH- induced oxidative stress in mediating METH use and in development of motivation to seek METH during abstinence. Furthermore, the results will benefit opioid and alcohol use disorder research as these disorders induce mitochondrial dysfunction. Lastly, since chronic use of METH, particularly at high doses, predisposes to development of Parkinson’s disease and potentially also to Alzheimer’s disease, the results from this research will add information to these research areas.