HIV-1 gp120-mediated injury in brain endothelium

描述(由申请人提供)：血脑屏障(BBB)的完整性对正常的大脑功能至关重要。艾滋病患者的神经病理障碍与血管周围HIV感染的巨噬细胞、胶质细胞增生和血脑屏障通透性异常有关。在患有HIV-1相关性痴呆(HAD)的艾滋病患者中，血脑屏障的分解是常见的。艾滋病毒引起这些病变的过程还没有被很好地理解。这项建议试图确定脑内皮细胞在HIV-1相关神经病理中的作用。HIV-1包膜糖蛋白gp120在HIV-1感染者的血清和脑脊液中被检测到，浓度在0.1 nM到1 nM之间，并且可以作为一种可溶性的介体。Gp120蛋白可以诱发神经毒性物质，并在艾滋病患者的大脑中检测到。这一建议的总体假设是：1)gp120可能与脑内皮细胞相互作用，导致细胞损伤，从而促进HIV进入中枢神经系统，并参与脑内的病理；2)脑内皮细胞可能通过gp120与脑内皮细胞表面的突触蛋白结合，作为促进HIV-1感染的微环境；以及3)阿片类药物可能由于gp120和阿片类药物对脑内皮细胞的协同毒性作用而加速HAD的进展。这项建议将表征gp120对人脑微血管内皮细胞(HBMEC)的致病作用，其病毒包膜gp120的浓度为体内发现的(0.1至1 nM)。本研究的目的是：1)通过与人脐静脉内皮细胞(HUVEC)比较，阐明gp120在体内外介导HBMEC损伤的信号通路，从而揭示gp120介导脑内皮细胞损伤的分子机制；2)确定突触素作为内皮细胞gp120结合受体的作用及其在HIV介导的脑内皮损伤中的作用；3)检测gp120与阿片类药物(吗啡)对HBMEC通透性的潜在协同毒性。在这些研究中，我们将同时研究M嗜性和T嗜性HIV毒株，因为每种毒株都可能出现在艾滋病过程中。这些研究应该为预防和/或治疗策略提供洞察力，以维持艾滋病毒感染患者的血脑屏障完整性，从而有助于限制中枢神经系统的病理。

DESCRIPTION (provided by applicant): The integrity of the blood-brain barrier (BBB) is critical for normal brain function. Neuropathological disorders in AIDS patients have been associated with perivascular HIV-infected macrophages, gliosis and abnormalities in the permeability of the BBB. Breakdown of the BBB is commonly seen in AIDS patients with HIV-1 associated dementia (HAD). The processes by which HIV causes these pathological changes are not well understood. This proposal seeks to characterize the role of brain endothelium in contributing to HIV-1 related neurological pathology. Gp120, the HIV-1 envelope glycoprotein, has been detected in the serum and cerebrospinal fluid of HIV-1 infected patients at 0.1 nM to 1 nM concentrations and can act as a soluble mediator. Gp120 protein can elicit neurotoxic substances and is detected in the brains of patients with AIDS. The overall hypotheses of this proposal are: 1) Gp120 may interact with brain endothelium and cause cell injury, thereby facilitating transit of HIV into the CNS as well as contributing to the pathology in brain; 2) brain endothelium may serve as a microenvironment which promotes HIV-1 infection in brain via the binding of Gp120 to the syndecans on the surface of brain endothelium; and 3) opioid drugs may hasten the progression of HAD due to a synergistic toxic effect of Gp120 and opioids on brain endothelium. This proposal will characterize the pathogenic effects of Gp120 on human brain microvascular endothelial cells (HBMEC), at concentrations of the viral envelope Gp120 that are found in vivo (0.1 to 1 nM). The aims of this research are: 1) to characterize the molecular mechanisms of Gp120 mediated injury of brain endothelium by elucidating the signaling pathways that mediate the injurious effects of Gp120 in HBMEC as compared to human umbilical vein endothelial cells (HUVEC) in-vitro and in-vivo; 2) to determine the role of syndecans as attachment receptors for Gp120 on endothelial cells and their role in HIV-mediated brain endothelium injury; and 3) to examine the potential synergistic toxicity of Gp120 and opioid drugs (morphine) on HBMEC permeability. In these studies, we will work with both M- and T-tropic HIV strains, since each can be present during the course of AIDS. These studies should provide insights into preventive and/or therapeutic strategies to sustain BBB integrity in HIV-infected patients, and thereby contribute to limiting CNS pathology.