HIV-1 Tat protein exposure alters the morphological characteristics and gene expression in the primary mouse cortex endothelial cells and human brain microvascular endothelial cells

HIV-1 viral proteins can disrupt tight junctions within the blood-brain barrier (BBB), directly compromising its structural and functional integrity. In this study, we investigated the effects of HIV-1 transactivator of transcription (Tat) protein on mouse prefrontal cortex endothelial cells (ECs) morphological alterations and gene expression profiles. Our results demonstrated that Tat-exposed ECs showed downregulated CD31 expression, increased phalloidin staining intensity, and activation of inflammatory response pathways as revealed by RNA-seq analysis, which is similar to the effects of Tat on human brain microvascular endothelial cells (HBMVECs). Overall design: Mouse ECs were cultured in the culture medium [DF12 (120 mg/mL), NaHCO3 (12 mg/mL), 1% Penicillin/Streptomycin, 10% FBS, Heparin (5 µg/mL), Insulin (5 µg/mL), Sodium selenite (5 ng/mL), 100 nM Hydrocortisone, Apo-transferrin (5 µg/mL), bFGF (1 µg/mL), and Puromycin (1 µg/mL), pH 7.2] and maintained at 37 °C in a 5% CO2 incubator for 10 days before Tat exposure. Cells were seeded on 96-well plate at a density of 10,000 cells/well and exposed to control medium containing 0.1% protease inhibitor cocktail for preventing Tat protein degradation or the same medium containing recombinant Tat1-86 at a 12.5 nM final concentration and incubated at 37°C, 5% CO2 incubator for 48 hours before RNA isolation.