The molecular mechanisms of astrocytes-neurons interaction in the morphine use disorder

阿片类药物使用障碍(OUD)对退伍军人的心理和身体健康有实质性的负面影响， 工作表现、住房状况和社会功能。年阿片类药物滥用已达到流行水平 美国。随着每日阿片类药物剂量的增加，过量死亡的风险增加。 止痛作用。退伍军人健康管理局(VHA)认识到成功 给我们的退伍军人开安全的阿片类药物。吗啡戒断是阿片类药物滥用的决定因素之一 在OUD患者中，其机制尚不清楚，有效的治疗方法仍然缺乏。 MW激活星形胶质细胞释放神经炎性因子。新出现的证据表明 反应性星形胶质细胞产生的神经炎性因子Lipocalin 2与多种神经性疾病相关 系统损伤和神经炎症。我们的初步数据显示，自发毫波(S-毫瓦)诱导 TLR4、NF-kB(relA/p65)和Lcn2的表达。LCN2受体(Lcn2-R)位于脑干 S-MW中脑导水管周围灰质神经元。表观遗传编写者EZH2通过生成 H3K27me3的甲基化表观遗传标记。我们的初步数据显示，S-MW增加了神经元 EZH2和pCREB，并降低PAG中抗氧化线粒体sirtuin 3(SIRT3)的表达。完全相同的 在S-MW中，星形胶质细胞对神经元活性的分子机制仍然知之甚少。在提案中， 我们将测试胶质细胞活动诱导星形胶质细胞来源的Lcn2释放的假设，Lcn2降低 神经元抗氧化SIRT3，最终增加S-MW小鼠PAG中的pCREB。具体目标1： 确定星形胶质细胞激活是否通过TLR4和NF-κB诱导LCN2的过度表达 S-MW对小鼠的vlPAG作用。特定目标2：确定Lcn2-R是否介导SIRT3表达下调 导致S-MW组小鼠vlPAG神经元pCREB表达增加。我们工作的一个重要特点是 能够因果地使用新的遗传/表观遗传和分子检测、细胞类型特异性条件基因敲除 (CKO)小鼠，细胞类型选择性病毒介导的基因转移，以及分子药理学方法。这个 该提议将为阿片类药物戒断的发病机制提供重要的见解，并为一种新的 阿片类药物戒断的治疗靶点。这项研究将在未来导致 为普通人群和退伍军人开发新药，基于我们对 TLR4-Lcn2-SIRT3-pCREB通路在阿片类药物戒断中的作用机制

Opioid use disorder (OUD) has substantial negative consequences on veterans' mental and physical health, work performance, housing status, and social function. Opioid drug abuse has reached an epidemic level in the United States. There is an increased risk of overdose death with higher daily opioid doses for increasing analgesic effect. The Veterans Health Administration (VHA) recognizes the clinical challenges to successfully prescribing opioids safely for our veterans. Morphine withdrawal (MW) is one of determinants of opiate abuse in OUD individuals, yet its mechanisms are poorly understood, and effective therapies are still lacking. MW activates astrocytes to release neuroinflammatory factors. Emerging evidence shows that neuroinflammatory factor Lipocalin 2 (LCN2) from reactive astrocytes is associated with a variety of nervous system injuries and neuroinflammation. Our preliminary data showed that spontaneous MW (S-MW) induced TLR4, NF-kB (RelA/p65), and LCN2 from astrocytes. LCN2 receptor (LCN2-R) is located in the brainstem periaqueductal gray (PAG) neurons in S-MW. Epigenetic writer EZH2 silences gene expression by generating a methylated epigenetic mark at H3K27me3. Our preliminary data showed that S-MW increased neuronal EZH2 and pCREB, and decreased anti-oxidative mitochondrial sirtuin 3 (Sirt3) in the PAG. The exact molecular mechanisms of astrocytes to neuron activity in S-MW remain poorly understood. In the proposal, we will test the hypothesis that glial activity induces the release of astrocytes-derived LCN2, which lowers neuronal anti-oxidative Sirt3 and finally increases pCREB in the PAG in mice with S-MW. Specific Aim 1: To determine whether astrocytic activation induces the overexpression of LCN2 through TLR4 and NF-κB in the vlPAG in mice with S-MW. Specific Aim 2: To define whether LCN2-R mediates the lowered Sirt3 expression leading to pCREB increases in the vlPAG neurons in mice with S-MW. A crucial feature of our work is the ability to causally use new genetic/epigenetic and molecular assay, cell-type specific conditional knockout (cKO) mice, cell type-selective viral-mediated gene transfer, and molecular-pharmacological approach. The proposal will provide important insights into the pathogenesis of opioid withdrawal, and shed light on a novel therapeutic target for opioid withdrawal of opioid withdrawal. The study will could lead, in the future, to the development of new drugs for both the general population and veterans, based on our identification of the mechanism of action of TLR4---LCN2---Sirt3---pCREB pathway during opioid withdrawal.