Effects of HIV PIs on CNS endothelial cells in NeuroAIDS

描述（由申请人提供）：长期的职业目标是：1）开发一个研究计划，以调查宿主-病原体相互作用引发的细胞信号改变与神经精神疾病，如艾滋病毒相关的痴呆症（HAD）和2）成为一个独立的生物医学科学家在一个学术机构。详细的职业发展和科学计划，解决高活性抗逆转录病毒疗法（HAART）的潜在贡献NeuroAIDS的建议。血清转换后不久，HIV患者可能会被规定蛋白酶抑制剂（PI）为基础的HAART方案。HAART已被证明在抑制全身病毒负荷方面非常成功;然而，ATP依赖性外排转运泵P-糖蛋白（P-gp）对NeuroAIDS的PI治疗造成了严重限制。由于病毒反弹、耐药性突变以及PI与HIV蛋白和脑内皮细胞（CEC）的潜在相互作用，本提案的主要目的是确定长期PI暴露对CEC响应宿主衍生生长因子（如成纤维细胞生长因子2（FGF 2））的能力的影响，这些蛋白质是在病毒反弹时作为抵抗HIV蛋白质的防御机制而产生的。我们假设长期暴露于PI如沙奎那韦（SQV）、茚地那韦（INV）、奈非那韦（NFV）和/或利托那韦（RTV）将改变P-gp流出依赖性表达和活性，从而改变FGF 2介导的小窝蛋白/ERK/NO系统中P-gp流出非依赖性信号通路。为此，AIM I将确定长期PI治疗对CEC适应性和FGF 2介导的信号转导（通过与P-gp和小窝蛋白的相互作用）的影响。将测试CEC适应性的四个方面：1）活力，2）P-gp表达和活性，3）P-gp介导的小窝蛋白和内皮一氧化氮合酶（eNOS）信号传导和一氧化氮（NO）产生，4）FGF 2介导的细胞外调节激酶（ERK）信号传导和血管生成能力。AIM II将在体外研究CEC长期暴露于PI如何破坏P-gp/小窝蛋白/FGF 2依赖性保护免受HIV蛋白gp 120的影响。使用MSR-gp 120和GFAPFGF 2转基因小鼠，AIM III将在体内研究长期PI治疗在与HIV蛋白相互作用期间破坏血脑屏障（BBB）信号传导的长期影响。了解慢性PI暴露后通过P-gp/小窝改变FGF 2信号传导的机制对于确定可能导致病毒反弹或病毒学失败期间与NeuroAIDS相关的神经和神经行为改变进展的因素非常重要。

DESCRIPTION (provided by applicant): Long-term career goals are to: 1) develop a research program to investigate the cellular signaling alterations triggered by host-pathogen interactions relevant to neuro-psychiatric disorders such as HIV-associated Dementia (HAD) and 2) become an independent bio-medical scientist at an academic institution. Detailed career development and scientific plans addressing the potential contribution of highly active anti-retroviral therapy (HAART) to NeuroAIDS is proposed. Shortly after sero-conversion, HIV patients may be prescribed protease inhibitor (PI)-based HAART regimens. HAART has proven highly successful in suppressing systemic viral burden; however, the ATP-dependent efflux transport pump, P-glycoprotein (P-gp), imposes a serious constraint on PI treatment of NeuroAIDS. Because of viral rebound, resistance mutations and the potential interactions of PIs with HIV proteins and cerebral endothelial cells (CEC), the main objective of this proposal is to determine the effects of chronic PI exposure on the CEC's ability to respond to host-derived growth factors, such as fibroblast growth factor 2 (FGF2), that are generated as defense mechanisms against HIV proteins _resent in the blood stream at viral rebound. We hypothesize that long-term exposure to PIs such as saquinavir (SQV), indinavir (INV), nelfinavir (NFV) and/or ritonavir (RTV) will modify P-gp efflux-dependent expression and activity, thereby altering P-gp efflux-independent signaling pathways in the FGF2-mediated caveolin/ERK/NO systems. For this purpose, AIM I will determine the effects of chronic PI treatment on CEC fitness and signaling mediated by FGF2 via interactions with P-gp and caveolin. Four aspects of CEC fitness will be tested: 1) viability, 2) P-gp expression and activity, 3) P-gp-mediated caveolin and endothelial nitric oxide synthase (eNOS) signaling and nitric oxide (NO) production, 4) FGF2-mediated extracellular regulated kinase (ERK) signaling and angiogenic capacity. AIM II will address in vitro, how chronic exposure of CEC to PI disrupts P-gp/caveolin/FGF2-dependent protection from the HIV protein, gp120. Using MSR-gp120 and GFAPFGF2 transgenic mice, AIM III will investigate, in vivo, the long-term effects of chronic PI treatment in disrupting signaling at the blood-brain barrier (BBB) during interaction with HIV proteins. Understanding the mechanisms responsible for alterations in FGF2 signaling via P-gp/caveolae after chronic PI exposure is important for identifying factors that may contribute to the progression of neurological and neurobehavioral alterations associated with NeuroAIDS during viral rebound or at virologic failure.