MiR-133b Improves Decidualization of Endometrial Stromal Cells by Targeting KLF12 in Recurrent Implantation Failure

Abstract Purpose Impaired decidualization contributes to the infertility in recurrent implantation failure (RIF). Herein, we focused on the function and probable mechanisms of miR-133b in endometrial stromal cells decidualization.Methods miR-133b and KLF12 protein levels in midsecretory endometrial tissues derived from women with and without RIF were measured by qRT-PCR and Western blot. Primary human endometrial stromal cells (HESCs) were isolated and cultured for in vitro decidualization assays. Luciferase reporter, qRT-PCR and Western blot assays were used to measure the relationship between miR-133b and KLF12.Results miR-133b was significantly downregulated, whereas KLF12 was upregulated in endometrial tissues from RIF. miR-133b effectively promoted HESCs in vitro decidualization through the modulation of KLF12 expression and the activation of LIF/STAT3 pathway. Conversely, inhibition of miR-133b expression reversed these effects. In addition, the luciferase reporter system demonstrated that miR-133b directly inhibited the expression of KLF12 by interacting with 3’ untranslated region of KLF12.Conclusion Our data suggest that miR-133b promotes HESCs decidualization by targeting KLF12 and reverses the impaired decidualization in RIF.