Mechanism of upregulated lncRNA MALAT1 on hypoxia-induced trophoblast functional impairment in preeclampsia
Objective To investigate the expression of long non-coding RNA MALAT1(lncRNA MALAT1)in placental tissues of patients with preeclampsia(PE),and to clarify its role in hypoxic-induced trophoblast functional injury.Methods Placental tissues were collected from 20 PE patients(PE group)and 20 healthy controls(NP group)from Dongguan People's Hospital from May 2020 to October 2022,quantitative reverse transcription polymerase chain reaction(qRT-PCR)was used to detect the mRNA expression differences of MALAT1 and autophagy related genes LC3 and Beclin-1 in placental tissues of two groups.Human trophoblast cell line HTR-8 was cultured in vitro and transfected with the overexpressed MALAT1 plasmid(MALAT1)or its negative control(pc-NC)plasmid using transient transfection technique.The cells were treated with hypoxia(Hyp)and divided into four groups:Control group,Hyp+pc-NC group,Hyp+MALAT1 group and Hyp+MALAT1+3-MA group with autophagy inhibitor 3-methyladenine(3-MA)treated.The proliferative activity of cells in each group was detected by CCK-8,the invasion ability of cells in each group was detected by Transwell,and the apoptosis of cells in each group was detected by TUNEL staining.The expressions of apoptosis-related proteins Bax,Bcl-2 and cleved caspase-3,and the expression of autophagy related protein Beclin-1 and the ratio of LC3-Ⅱ/Ⅰ were detected by Western blotting.Results Compared with NP group,the expression levels of MALAT1,LC3 and Beclin-1 mRNA in PE group were significantly decreased(P＜0.01).Compared with Control group,cell proliferation activity,invasion ability,Bcl-2 Beclin-1 protein expression and LC3-Ⅱ/Ⅰ ratio in Hyp+pc-NC group,Hyp+MALAT1 and Hyp+MALAT1+3-MA groups were significantly decreased(P＜0.05).However,the apoptosis rate and the expression levels of Bax and cleved caspase-3 protein were significantly increased(P＜0.05).Compared with Hyp+pc-NC group,proliferation activity,invasion ability,Bcl-2 and Beclin-l protein expression and LC3-11/Ⅰ ratio were significantly increased in Hyp+MALAT1 group(P＜0.05),while cell apoptosis rate,Bax and cleved caspase-3 protein expression levels were significantly decreased(P＜0.05).In Hyp+MALAT1+3-MA group,the proliferative activity,invasion ability,the expression of Bcl-2 and Beclin-1 protein and the ratio of LC3-Ⅱ/Ⅰ were significantly decreased(P＜0.05),but the apoptosis rate,the expression levels of Bax and cleved caspase-3 were significantly increased(P＜0.05).Compared with Hyp+MALAT1 group,cell proliferation activity,invasion ability,Bcl-2 and Beclin-1 protein expression and LC3-Ⅱ/Ⅰ ratio in Hyp+MALAT1+3-MA group were significantly decreased(P＜0.05).However,the apoptosis rate and the expression levels of Bax and cleved caspase-3 protein were significantly increased(P＜0.05).Conclusions The expression of MALAT1 in placental tissue of PE patients is significantly decreased.Up-regulation of MALAT1 expression can improve hypoxy-induced trophoblast proliferation and invasion injury,and inhibit cell apoptosis by promoting autophagy level.
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