Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, 33136, USA.
Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, 33136, USA.
Neurobiol Dis. 2021 Jul;155:105388. doi: 10.1016/j.nbd.2021.105388. Epub 2021 May 5.
Human immunodeficiency virus-1 (HIV-1) has been shown to cross the blood-brain barrier and cause HIV-associated neurocognitive disorders (HAND) through a process that may involve direct or indirect interactions with the central nervous system (CNS) cells and alterations of amyloid β (Aβ) homeostasis. The present study focused on the mechanisms of HIV-1 infecting human neural progenitor cells (hNPCs) and affecting NPC intercellular communications with human brain endothelial cells (HBMEC). Despite the lack of the CD4 receptor, hNPCs were effectively infected by HIV-1 via a mechanism involving the chemokine receptors, CXCR4 and CCR5. HIV-1 infection increased expression of connexin-43 (Cx43), phosphorylated Cx43 (pCx43), and pannexin 2 (Panx2) protein levels in hNPCs, suggesting alterations in gap-junction (GJ) and pannexin channel communication. Indeed, a functional GJ assay indicated an increase in communication between HIV-infected hNPCs and non-infected HBMEC. We next analyzed the impact of HBMEC-derived extracellular vesicles (EVs) and EVs carrying Aβ (EV-Aβ) on the expression of Cx43, pCx43, and Panx2 in HIV-1 infected and non-infected hNPCs. Exposure to EV-Aβ resulted in significant reduction of Cx43 and pCx43 protein expression in non-infected hNPCs when compared to EV controls. Interestingly, EV-Aβ treatment significantly increased levels of Cx43, pCx43, and Panx2 in HIV-1-infected hNPCs when compared to non-infected controls. These results were confirmed in a GJ functional assay and an ATP release assay, which is an indicator of connexin hemichannel and/or pannexin channel functions. Overall, the current study demonstrates the importance of hNPCs in HIV-1 infection and indicates that intercellular communications between infected hNPCs and HBMEC can be effectively modulated by EVs carrying Aβ as their cargo.
人类免疫缺陷病毒 1（HIV-1）已被证明可以穿过血脑屏障，并通过可能涉及与中枢神经系统（CNS）细胞的直接或间接相互作用以及淀粉样β（Aβ）动态平衡改变的过程，引起与 HIV 相关的神经认知障碍（HAND）。本研究集中于 HIV-1 感染人神经祖细胞（hNPC）并影响 NPC 与人脑内皮细胞（HBMEC）之间细胞间通讯的机制。尽管缺乏 CD4 受体，hNPC 仍可通过涉及趋化因子受体 CXCR4 和 CCR5 的机制被 HIV-1 有效感染。HIV-1 感染增加了 hNPC 中连接蛋白 43（Cx43）、磷酸化 Cx43（pCx43）和连接蛋白 2（Panx2）蛋白水平的表达，表明缝隙连接（GJ）和连接蛋白通道通讯发生改变。实际上，功能性 GJ 测定表明，感染 HIV 的 hNPC 与未感染的 HBMEC 之间的通讯增加。接下来，我们分析了源自 HBMEC 的细胞外囊泡（EV）和携带 Aβ 的 EV（EV-Aβ）对 HIV-1 感染和未感染的 hNPC 中 Cx43、pCx43 和 Panx2 表达的影响。与 EV 对照相比，EV-Aβ 暴露导致未感染的 hNPC 中 Cx43 和 pCx43 蛋白表达显著降低。有趣的是，与未感染对照相比，EV-Aβ 处理可显著增加 HIV-1 感染的 hNPC 中 Cx43、pCx43 和 Panx2 的水平。这些结果在 GJ 功能测定和 ATP 释放测定中得到了证实，这是连接蛋白半通道和/或连接蛋白通道功能的指标。总的来说，本研究证明了 hNPC 在 HIV-1 感染中的重要性，并表明携带 Aβ 的 EV 作为其货物可以有效调节感染的 hNPC 与 HBMEC 之间的细胞间通讯。
