Expression of mmu-miR-96 in the endometrium during early pregnancy and its regulatory effects on stromal cell apoptosis via Bcl2

Decidualization of endometrial stromal cells is an important feature of implantation and pregnancy. The molecular mechanism underlying decidualization remains unclear, particularly regarding the microRNA (miRNA/miR) regulation of this process. The present study revealed the temporal and spatial distribution of mmu-miR-96 in the mouse uterus during early pregnancy by reverse transcription-quantitative polymerase chain reaction and in situ hybridization. In addition, primary stromal cells were isolated from the mouse uterus and used to explore the role of mmu-miR-96 in decidualization. The results demonstrated that mmu-miR-96 was highly expressed in stromal cells during pregnancy, and was upregulated at implantation sites. In addition, mmu-miR-96 was strongly expressed during decidualization, which indicates that it may serve a role in the decidualization of stromal cells. Based on existing reports, mmu-miR-96 participates in apoptosis; therefore the present study investigated its effects on the apoptosis of primary endometrial stromal cells. The results indicated that overexpression of mmu-miR-96 may induce apoptosis of stromal cells. In further studies regarding the underlying mechanism, the target genes of mmu-miR-96 were screened by bioinformatics analysis, and it was confirmed that B-cell lymphoma 2, an anti-apoptotic gene, was the target of mmu-miR-96, as determined using a reporter gene assay. In conclusion, the present study suggested that mmu-miR-96 participates in the decidualization of endometrial stromal cells in mice, thereby serving a key role in pregnancy.