miR-204 Negatively Regulates HIV-Tat-Mediated Inflammation in Cervical Epithelial Cells via the NF-κB Axis: Insights from an In Vitro Study.

Despite antiretroviral therapy, HIV proteins, such as Tat, persist in tissues, driving chronic inflammation. Cervical inflammation in females not only accelerates HIV progression but also increases the risk of other STIs; hence, understanding the underlying factors/regulators is vital. However, Tat-induced cervical inflammation and its regulation are hitherto poorly understood, which we investigated using TZM-bl cells. Tat stimulation in these cervical epithelial cells significantly increased the expression of various inflammatory mediators, including cytokines (IL-1β, TNF-α, IL-6, IL-17a, GM-CSF), chemokines (MIP-1α, MIP-1β), adhesion molecules (ICAM-1, P-Selectin, E-Selectin), and ROS. Further upregulation of inflammatory mediators (NF-κB, IRAK-4) along with TLR7 was observed in Tat-stimulated cells. Interestingly, Tat stimulation decreased miR-204-5p expression in these cells, suggesting a role in regulating Tat-mediated inflammatory processes. Using a gain-of-function approach, we further observed that the overexpression of miR-204-5p reduced the expression of IL-1β, TNF-α, IL-6, MIP-1α, MIP-1β, ICAM-1, P-Selectin, and ROS in the Tat-stimulated TZM-bl cells, along with NF-κB, IRAK-1, and IRAK-4. Using Western blotting and luciferase assays, miR-204-5p was further shown to directly target NF-κB. Here, we report that HIV-1 Tat stimulation in cervical epithelial cells downregulates hsa-miR-204-5p, thereby activating the pro-inflammatory TLR7/NF-κB axis, highlighting its relevance to understanding mechanisms underlying cervical inflammation.