Pre-Exposure Prophylaxis (PrEP) inhibits oligodendrocyte differentiation in vivo

项目概要： 每年，13 岁至 24 岁的人在被诊断患有此病的人数中所占比例过高 美国的人类免疫缺陷病毒（HIV）。暴露前预防 (PrEP) 每日一次的抗逆转录病毒治疗是预防艾滋病毒传播的有效方法 然而，这种治疗方案对感染艾滋病毒的风险很大的青少年 青春期期间关键大脑结构的发育尚不清楚。服用 PrEP 的青少年 由于青少年大脑正在经历高速率，因此特别容易受到髓磷脂损伤 髓鞘形成。我们的实验室表明，原代少突胶质细胞前体细胞培养物经过处理 选择抗逆转录病毒药物的治疗浓度显示出剂量依赖性 少突胶质细胞成熟度降低。我们知识上的差距是这一现象的机械基础 抗逆转录病毒药物对 HIV 阴性青少年少突胶质细胞成熟的抑制作用 人口。我的初步数据表明恩曲他滨 (FTC) 和替诺福韦二吡呋酯 富马酸盐（TDF），组成 PrEP 的药物，使少突胶质细胞溶酶体脱酸。此外， 我的初步数据还表明 PrEP 会降低少突胶质细胞中的 SREBP2 表达 体外。 mTORC1 通过转录因子 SREBP 1 和 2 调节脂肪生成， 后者调节参与胆固醇合成的基因的表达，这是限速步骤 髓鞘形成。溶酶体脱酸已被证明会导致 mTORC1 增加 破骨细胞中的信号传导，但在少突胶质细胞中仍有待研究。另外， 少突胶质细胞中 mTORC1 的过度激活已知会导致髓鞘形成不足和 SREBP2 表达减少。综上所述，我假设少突胶质细胞成熟 通过溶酶体脱酸作用被 PrEP 抑制，导致 mTORC1 激活增加 并减少脂肪生成。我将在以下具体目标中阐述这一假设。目标 1 我将证明 PrEP 通过溶酶体去削弱少突胶质细胞的成熟 体外酸化。在目标 2 中，我将证明 PrEP 抑制少突胶质细胞成熟 通过增加 mTORC1 信号传导并随后减少体外脂肪生成。在目标 3 中， 我将证明 PrEP 会损害少突胶质细胞的成熟和髓鞘形成， 溶酶体酸化可挽救体内髓鞘形成。总的来说，这些实验将研究 先前未解答的问题是 PrEP 是否影响 HIV 中少突胶质细胞的成熟 消极的个体。

PROJECT SUMMARY: Each year 13- to 24-year-olds disproportionately compose the number individuals diagnosed with human immunodeficiency virus (HIV) in the United States. Preexposure prophylaxis (PrEP), a once daily antiretroviral regime, is an effective method to prevent the transmission of HIV in adolescents at substantial risk for acquiring HIV, however, the effect of this regimen on the development of critical brain structures during adolescence is unknown. Adolescents taking PrEP are uniquely vulnerable to myelin impairments as the adolescent brain is undergoing high rates of myelination. Our lab has shown that primary oligodendrocyte precursor cell cultures treated with therapeutic concentrations of select antiretroviral drugs displayed dose-dependent decreases in oligodendrocyte maturation. A gap in our knowledge is the mechanistic basis of the inhibition of oligodendrocyte maturation by antiretrovirals in an HIV-negative, adolescent population. My preliminary data suggests that emtricitabine (FTC) and tenofovir disoproxil fumarate (TDF), the drugs composing PrEP, de-acidify oligodendrocyte lysosomes. Furthermore, my preliminary data also suggests that PrEP decreases SREBP2 expression in oligodendrocytes in vitro. mTORC1 regulates lipogenesis through the transcription factors SREBP 1 and 2, with the latter regulating the expression of genes involved in cholesterol synthesis, the rate-limiting step of myelination. Lysosome de-acidification has been shown to result in increased mTORC1 signaling in osteoclasts but remains to be investigated in oligodendrocytes. Additionally, overactivation of mTORC1 in oligodendrocytes is known to result in hypomyelination and decreased SREBP2 expression. Taken together, I hypothesize that oligodendrocyte maturation is inhibited by PrEP through lysosome deacidification resulting in increased mTORC1 activation and decreased lipogenesis. I will address this hypothesis in the following specific aims. In Aim 1 I will demonstrate oligodendrocyte maturation is impaired by PrEP through lysosome de- acidification in vitro. In Aim 2, I will demonstrate that PrEP inhibits oligodendrocyte maturation through increased mTORC1 signaling and subsequent decreased lipogenesis in vitro. In Aim 3, I will demonstrate that oligodendrocyte maturation and myelination are impaired by PrEP and lysosome acidification rescues myelination in vivo. Overall, these experiments will investigate the previously unanswered question of whether PrEP affects oligodendrocyte maturation in HIV- negative individuals.