LncRNA MALAT1 对 PCOS 颗粒细胞凋亡、自噬和 PI3K/Akt/mTOR 通路的影响.

Objective To investigate the impacts of long non-coding RNA-lung adenocarcinoma metastasis- associated transcripton-1 (lncRNA MALAT1) on apoptosis, autophagy and phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt)/mammalian rapasin target protein (mTOR) pathway in granulosa cells of polycystic ovary syndrome (PCOS). Methods The expression levels of lncRNA MALAT1 in PCOS ovarian tissue, normal ovarian tissue, human ovarian granulosa cells (KGN) and normal ovarian epithelial cells IOSE80 were detected by qRT-PCR. KGN cells were cultured in vitro and grouped into the control group, the si-NC group, the si-MALAT1 group, the pc-NC group, the pc-MALAT1 group and the pc-MALAT1+740Y-P (PI3K activator) group. qRT-PCR was applied to detect the expression level of MALAT1 mRNA in cells of each transfection group. CCK-8 was applied to detect cell viability. Flow cytometry was applied to detect cell apoptosis rate. Transmission electron microscopy was applied to observe autophagosomes in KGN cells. Western blot assay was applied to detect expression levels of B-cell lymphoma 2 (Bcl-2), Bcl-2 associated X protein (Bax), microtubule- associated protein Ⅱ light chain 3 (LC3 Ⅱ), microtubule-associated protein Ⅰ light chain 3 (LC3 Ⅰ), Beclin1, p-PI3K, PI3K, p-Akt, Akt, p-mTOR and mTOR proteins in cells. Results The expression level of MALAT1 mRNA in PCOS ovarian tissue was lower than that in normal ovarian tissue, and that in KGN cells was lower than that in normal ovarian epithelial IOSE80 cells. A small number of autophagosomes were observed in KGN cells in the control group. After interfering MALAT1 expression, OD450 values (24, 48 and 72 hours) and the Bcl-2 protein expression of KGN cells were reduced, and the apoptosis rate, the expression of Bax, LC3 Ⅱ/LC3 Ⅰ, Beclin1, p-PI3K/PI3K, p-Akt/Akt and p-mTOR/ mTOR proteins were increased (P＜0.05). The number of autophagosomes increased. Changes of the above indexes were reversed after overexpression of MALAT1 (P＜0.05). Compared with the pc-MALAT1 group, the OD450 values (24, 48, 72 h), and the expression of Bcl-2 protein were obviously reduced in the pc-MALAT1+740Y-P group, while the apoptosis rate, number of autophagosomes, the expression of Bax, LC3 Ⅱ/LC3 Ⅰ, Beclin1, p-PI3K/PI3K, p-Akt/Akt, and p-mTOR/mTOR proteins were obviously increased (P＜0.05). The number of autophagosomes increased. Conclusion Overexpression of MALAT1 may inhibit apoptosis and autophagy in PCOS granulosa cells by inhibiting the PI3K/Akt/mTOR signaling pathway. [ABSTRACT FROM AUTHOR]