LncRNA MALAT1 inhibits apoptosis of endometrial stromal cells through miR-126-5p-CREB1 axis by activating PI3K-AKT pathway.

Endometriosis is a common, chronic and painful disease in women, whose pathogenesis remains not entirely clear. Long non-coding RNA (lncRNA) MALAT1 participates in the development of endometriosis. This study further investigated the regulation of MALAT1-miR-126-5p-CREB1 axis in the pathological process of endometriosis. MALAT1, miR-126-5p, and CREB1 levels in human endometrial stromal cells (HESCs) were detected by quantitative reverse transcription polymerase chain reaction (RT-qPCR). Protein levels were determined by Western blotting. Cell viability and apoptosis was assessed by MTT assay and annexin V-FITC staining, respectively. The interactivity between miR-126-5p and MALAT1 (or CREB1) was assessed by dual luciferase reporter system. Knockdown of MALAT1 or CREB1 restrained proliferation and induced apoptosis as confirmed by upregulating cleaved caspase-3 and Bax, and down-regulating Bcl-2 in HESCs, while inhibition of miR-126-5p presented the opposite results. Moreover, silencing of MALAT1 triggered apoptosis of HESCs via targeting miR-126-5p. In addition, miR-126-5p directly regulated CREB1 expression via binding to its 3' non-coding region. Finally, miR-126-5p inhibitor-mediated apoptosis inhibition was restrained by CREB1 silencing via inactivation of PI3K-AKT pathway in HESCs. Taken together, our study firstly demonstrates that MALAT1 regulates apoptosis of HESCs through miR-126-5p/CREB1 axis mediated PI3K/AKT pathway. Our findings explained the pathogenesis of endometriosis and offered promising therapeutic option for endometriosis.