Mechanism of microRNA-152 Regulating Decidual Natural Killer Cell Viability and Affecting Trophoblast Cell Invasiveness via the HLA-G/KIR2DL4 Axis

Abstract

Trophoblast cells are specialized placental epithelial cells essential for pregnancy maintenance. miR-152 is implicated in trophoblast cell regulation and pregnancy failure. This study explores the role of miR-152 in decidual natural killer (dNK) cell viability and trophoblast cell invasion. HTR-8/SVneo cells were transfected with miR-152-mimics/inhibitor or their respective controls, followed by co-culture with dNK cells. RT-qPCR assessed transfection efficiency, while cytokine secretion (IL-8, IP-10, VEGF), cell viability, apoptosis, and invasion were evaluated via ELISA, CCK-8, flow cytometry, Western blot, and Transwell assays. The interaction between miR-152 and HLA-G was examined via dual-luciferase reporter assay, and HLA-G/sHLA-G levels were measured. Co-cultures of dNK cells and miR-152/HLA-G-overexpressing HTR-8/SVneo cells were established, and anti-KIR2DL4/IgG1 was used to block HLA-G/KIR2DL4 binding. Co-immunoprecipitation confirmed protein interactions. miR-152 overexpression suppressed dNK cell cytokine secretion, reduced HTR-8/SVneo cell viability and invasion, and promoted apoptosis. miR-152 inhibition had the opposite effect. miR-152 directly targeted HLA-G, and HLA-G overexpression rescued dNK function and trophoblast invasion. Blocking the HLA-G/KIR2DL4 binding counteracted the effects of miR-152. miR-152 inhibits dNK cell function and trophoblast invasion by targeting HLA-G, reducing HLA-G/KIR2DL4 interaction. These findings highlight a potential regulatory mechanism in pregnancy maintenance.

Keywords: HLA‐G/KIR2DL4; HTR‐8/SVneo cells; cytokines; decidual natural killer cells; miR‐152.