Role of Exosomes in the Crosstalk Between Brain Endothelium and HIV Neuroinvasion

总结 外泌体正在出现，在免疫监视和神经元存活中发挥重要作用。 中枢神经系统（CNS），因为它们介导神经元之间的细胞间通讯， 其他脑细胞，包括星形胶质细胞和神经血管内皮细胞。然而， 外泌体在HIV介导的神经侵袭中的作用在很大程度上是未知的。我们最近发现外泌体 从HIV感染受试者的血浆中分离的miR-17含有显著高水平的microRNA-17（miR-17）， 17)以及可靶向紧密连接蛋白ZO-1和JAM-2的miR-20 a。进一步的试点研究使用细胞 培养物来源的外泌体显示，来自HIV感染的巨噬细胞的外泌体破坏了血脑 屏障（BBB）完整性。因此，我们假设来源于HIV感染者血浆的外泌体， 受试者含有损害BBB功能的miRNA，促进向器官的病毒传播 导致神经退化我们提出两个具体目标来解决这个问题 假设：目标1。研究来自HIV感染受试者的血浆外泌体或 未感染的对照对BBB功能的影响，并鉴定miR-17和miR-20 a在此过程中的作用。目标2. 为了分析和比较HIV感染者血浆和脑脊液中外来体的miRNA谱， 受感染的受试者有或没有神经认知障碍。外泌体的功能意义和 差异表达的外泌体miRNAs将在神经元存活、星形胶质细胞增殖、神经胶质细胞凋亡和神经元凋亡中得到验证。 分化和BBB功能。该项目，在体外和体内研究，应提供新的 对中枢神经系统HIV感染的发病机理的认识。

Summary Exosomes are emerging to play an important role in immune surveillance and neuronal survival of the central nervous system (CNS), as they mediate the intercellular communications between neurons and other brain cells, including astrocytes and neurovascular endothelial cells. However, the role of exosomes in HIV-mediated neuroinvasion is largely unknown. We recently identified that exosomes isolated from the plasma of HIV-infected subjects contain significantly high levels of microRNA-17 (miR- 17) and miR-20a that can target tight junction proteins ZO-1 and JAM-2. A further pilot study using cell culture-derived exosomes showed that exosomes from HIV-infected macrophages breached blood-brain barrier (BBB) integrity. Thus, we hypothesize that exosomes derived from plasma of HIV-infected subjects contain miRNAs that impair BBB functions, facilitating organotropic viral dissemination to the brain and resulting in neurodegeneration. We propose two specific aims to address this hypothesis: Aim 1. To investigate the effect of plasma exosomes from HIV-infected subjects or uninfected controls on BBB functions and identify the role of miR-17 and miR-20a in this process. Aim 2. To profile and compare the miRNA spectra of exosomes from the plasma and cerebrospinal fluid of HIV- infected subjects with or without neurocognitive disorders. The functional significance of the exosomes and the differentially expressed exosomal miRNAs will be validated on neuronal survival, astroglial differentiation and BBB functions. This project, with both in vitro and in vivo studies, should provide novel pathogenetic insights into HIV infection of the CNS.