HIV Neural Apoptosis:Mechanisms, Pathways & Protection

描述（由申请人提供）：神经元凋亡是艾滋病痴呆复合体（ADC）的一个标志，可能是HIV感染的巨噬细胞（HIV/MDM）释放神经毒素导致细胞死亡的最终共同途径。某些形式的神经元凋亡被bct-2gone家族的某些抗凋亡成员（Bcl-2和Bcl-xL）阻断，它们阻断了内在（线粒体相关）途径。AKT/蛋白激酶B信号（AKT/PKB）的激活也可能阻断神经元凋亡，AKT/PKB作用于涉及内源性和外源性（死亡受体相关）凋亡通路的点。内在和/或外在的细胞凋亡途径如何参与ADC的神经元凋亡尚不清楚，这代表了我们对HIV神经发病机制和神经保护策略的理解的重要空白。我们基于一种独特的人类神经元细胞系（NT2.N）开发了一种新的hiv诱导的神经元凋亡体外模型。我们发现Bcl-2和Bcl-xL以及神经元AKT/PKB的激活剂可以阻断HIV/ mdm诱导的神经元凋亡。我们还证实了新描述的7跨膜HIV共受体APJ在神经元中的表达，并发现其天然配体apelin激活AKT/PKB并阻断这种细胞凋亡。最后，我们使用了一种新的单细胞mRNA扩增技术来分析体内凋亡神经元的基因表达。我们的假设是，HIV诱导的神经元凋亡是通过特定途径介导的，包括内在和外在的凋亡机制，这些机制可能由HIV/MDM和HIV蛋白诱导，APJ激活的信号可能调节这些途径并介导针对HIV相关凋亡效应物的神经保护反应。我们的目的是通过体外模型和分析凋亡神经元的基因表达，更好地了解hiv诱导的神经元凋亡途径和apelin/APJ神经保护机制。我们将：1)确定HIV/MDM及其相关神经毒素诱导神经元凋亡的途径；2)明确APJ/apelin对HIV/MDM的神经保护信号通路；3)在hiv感染的大脑中确定的凋亡神经元亚类中调节内源性和外源性凋亡途径和神经保护途径的基因表达。

DESCRIPTION (provided by applicant): Neuronal apoptosis is a hallmark of AIDS dementia complex (ADC), and may represent a final common pathway of cell death in response to neurotoxins released from HIV-infected macrophages(HIV/MDM). Some forms of neuronal apoptosis are blocked by certain anti-apoptosis members of the bct-2gone family (Bcl-2 & Bcl-xL), which block the intrinsic (mitochondrial-associated) pathway. Neuronal apoptosis may also be blocked by activation of AKT/protein kinase B signaling (AKT/PKB), which acts at points involving the intrinsic and extrinsic (death receptor-associated) apoptosis pathways. How the intrinsic and/or extrinsic apoptosis pathways are involved in neuronal apoptosis in ADC is unknown, and this represents an important gap in our understanding of HIV neuropathogenesis and neuroprotective strategies. We have developed a novel in vitro model for HIV-induced neuronal apoptosis based on a unique human neuronal cell line (NT2.N). We found that Bcl-2 & Bcl-xL as well as activators of neuronal AKT/PKB block HIV/MDM-induced neuronal apoptosis. We have also demonstrated expression of the newly described seven-transmembrane HIV co-receptor APJ in neurons, and found that its native ligand, apelin, activates AKT/PKB and blocks such apoptosis. Finally, we have used a novel single-cell mRNA amplification technique to analyze gene expression in apoptotic neurons in vivo. Our hypothesis is that HIV induced neuronal apoptosis is mediated through specific pathways involving both intrinsic & extrinsic apoptosis mechanisms that may be differentially induced by HIV/MDM and HIV proteins, and that APJ activated signaling may modulate these pathways and mediate neuroprotective responses against effectors of HIV-associated apoptosis. Our aim is to better understand the pathways of HIV-induced neuronal apoptosis and the mechanisms of apelin/APJ neuroprotection, through our in vitro model and analysis of gene expression in apoptotic neurons in rive. We will: 1) Determine the pathways of neuronal apoptosis induced by HIV/MDM &: associated neurotoxins; 2) Define the neuroprotective signaling pathways for APJ/apelin against HIV/MDM; and 3) Determine the expression of genes modulating intrinsic & extrinsic apoptosis pathways and neuroprotective pathways in defined subclasses of apoptotic neurons in HIV-infected brain.