Tenofovir exerts antiviral effects in pregnant women with chronic hepatitis B by influencing the expression of miR‐21‐5p

Abstract Objective In pregnant women with chronic hepatitis B (CHB), tenofovir (TDF) has demonstrated significant efficacy in disrupting the replication of the hepatitis B virus (HBV) and in preventing mother‐to‐child transmission (MTCT). This study seeks to elucidate the role of miR‐21‐5p in mediating the antiviral effect of TDF. Methods Initially, the levels of miR‐21‐5p in pregnant women with and without CHB were compared by RT‐qPCR assay. Subsequently, a comparison was made between the levels of HBV and miR‐21‐5p prior to and following treatment with TDF. Moreover, the correlation between miR‐21‐5p levels and HBV DNA, HBsAg or HBeAg was analyzed by Pearson correlation analysis. Lastly, HBV‐infected huh‐7 cells were cultured in vitro. Then, RT‐qPCR and ELISA assays were conducted to investigate the influence of modulating miR‐21‐5p levels on HBV replication. Results miR‐21‐5p levels were significantly increased in CHB pregnant women. Following treatment with TDF, HBV was effectively controlled. More crucially, TDF led to a reduction in miR‐21‐5p levels. The level of miR‐21‐5p exhibited a positive correlation with HBV DNA, HBsAg and HBeAg. In cell experiments, the inhibition of miR‐21‐5p resulted in a significant decrease in levels of HBV DNA, HBsAg, and HBeAg. Conversely, overexpression of miR‐21‐5p yielded opposing results. Conclusion In pregnant women with CHB, TDF may inhibit HBV replication by inhibiting the expression of miR‐21‐5p. This mechanism contributes to the mitigation of infection exacerbation.