Department of Hematology, Affiliated Hospital 2 of Nantong University and First People's Hospital of Nantong City, Nantong, 226001, People's Republic of China.
Department of Oncology, Nantong Hospital of Traditional Chinese Medicine, Affiliated Traditional Chinese Medicine Hospital of Nantong University, Nantong, 226001, People's Republic of China.
J Neurovirol. 2022 Dec;28(4-6):483-496. doi: 10.1007/s13365-022-01094-z. Epub 2022 Sep 7.
Fatty acid-binding proteins (FABPs) are relevant to multiple neurodegenerative diseases. However, the roles and mechanisms of FABPs in HIV-associated neurocognitive disorder (HAND) remain yet unclear. In this study, cultured BV-2 microglial cells and HT-22 neuronal cells were used for in vitro experiments and HAND mouse models were constructed through intracerebroventricular injection of lentiviral vectors for in vivo experiments. FABP expression was determined using quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot. The interrelationship between Fabp4 and NF-κB signaling was investigated using chromatin immunoprecipitation, qRT-PCR, and Western blot. The role of Fabp4 in regulating inflammatory response was determined using qRT-PCR, enzyme-linked immunosorbent assay, Western blot, and immunofluorescence staining. Cell viability and apoptosis were analyzed using cell counting kit-8 assay and flow cytometry assay, respectively. Our results suggested an upregulation of Fabp4 expression in the presence of Tat. Tat-induced Fabp4 expression was directly regulated by NF-κB p65, followed by, Fabp4 facilitating Tat-activated NF-κB signaling pathway. We also observed that Fabp4 knockdown in microglial cells significantly suppressed inflammatory response and neuronal apoptosis both in vitro and in vivo. In conclusion, the presence of Tat in microglial cells results in Fabp4 and NF-κB to form a positive feedback loop leading to exacerbate inflammatory response and neuronal apoptosis.
脂肪酸结合蛋白（FABPs）与多种神经退行性疾病相关。然而，FABPs 在人类免疫缺陷病毒相关神经认知障碍（HAND）中的作用和机制尚不清楚。在这项研究中，使用体外实验培养的 BV-2 小胶质细胞和 HT-22 神经元细胞，并通过侧脑室注射慢病毒载体构建 HAND 小鼠模型进行体内实验。使用定量逆转录聚合酶链反应（qRT-PCR）和 Western blot 测定 FABP 表达。使用染色质免疫沉淀、qRT-PCR 和 Western blot 研究 Fabp4 与 NF-κB 信号之间的相互关系。使用 qRT-PCR、酶联免疫吸附测定、Western blot 和免疫荧光染色测定 Fabp4 在调节炎症反应中的作用。使用细胞计数试剂盒-8 测定法和流式细胞术分别分析细胞活力和细胞凋亡。我们的结果表明 Tat 存在时 Fabp4 表达上调。Tat 诱导的 Fabp4 表达受 NF-κB p65 的直接调控，随后 Fabp4 促进 Tat 激活的 NF-κB 信号通路。我们还观察到，小胶质细胞中的 Fabp4 敲低在体外和体内均显著抑制炎症反应和神经元凋亡。总之，Tat 存在于小胶质细胞中导致 Fabp4 和 NF-κB 形成正反馈回路，从而加剧炎症反应和神经元凋亡。
