MALAT1抑制Aβ_(25-35)诱导的人神经母细胞瘤SH-SY5Y细胞增殖并促进细胞凋亡及其机制

MALAT1 inhibits proliferation and promotes apoptosis of SH-SY5Y cells induced by Aβ_(25-35) via blocking PI3K/mTOR/GSK3β pathway

目的探讨长链非编码RNA转移相关肺腺癌转录本1(MALAT1)对Aβ_(25-35)诱导的阿尔茨海默病(AD)神经细胞的细胞周期、细胞增殖凋亡的影响。方法利用β淀粉样肽25-35(Aβ_(25-35))处理人神经母细胞瘤细胞SHSY5Y建立AD细胞模型。将AD SH-SY5Y细胞随机分为对照组、p CDH空载体(p CDH-EV)组、MALAT1过表达(p CDH-MALAT1)组、抑制表达空载体(p SICOR-EV)组、抑制MALAT1表达(p SICOR-sh MALAT1)组。噻唑蓝(MTT)法检测各组细胞增殖活性,流式细胞术检测转染48 h后的细胞周期和细胞凋亡率,Western blot法检测细胞BAX、Bcl2、胱天蛋白酶3(caspase-3)以及磷脂酰肌醇3激酶(PI3K)、磷酸化的PI3K(p-PI3K)、哺乳动物雷帕霉素靶蛋白(mTOR)和磷酸化的mTOR(p-mTOR)、糖原合成酶激酶3β(GSK3β)、磷酸化的GSK3β(p-GSK3β)蛋白水平。结果成功构建AD细胞模型和过表达及敲低MALAT1的表达载体。敲低MALAT1水平后,显著抑制AD模型细胞的增殖、细胞阻滞于G1期、促进细胞凋亡。同时上调BAX、caspase-3蛋白水平,下调Bcl2、p-PI3K、p-mTOR、p-GSK3β蛋白水平。过表达MALAT1则可逆转以上作用。结论敲低MALAT1水平可阻断PI3K/mTOR/GSK3β通路抑制Aβ25-35诱导的SH-SY5Y细胞增殖,促进细胞凋亡。

Objective To investigate the effects of long non-coding RNA（ lncRNA） metastasis-associated lung adenocarcinoma transcript 1（ MALAT1） on cell cycle,proliferation and apoptosis in SH-SY5 Y model cells of Alzheimer’s disease（ AD）.Methods The AD model cells（ SH-SY5 Y human neuroblastoma cells） were constructed using Aβ25-35. The AD cells were randomly divided into five groups： control group,over-expressed empty victor（ p CDH-EV） group,MALAT1 over-expression（ p CDH-MALAT1） group,MALAT1 expression inhibition of empty victor（ p SICOR-EV） group,and MALAT1 expression inhibition（ p SICOR-sh MALAT1） group. The cell proliferation activity of all the groups was detected by MTT assay. The cell cycle and apoptosis rate were detected by flow cytometry after 48 hours of transfection. Western blot analysis was used to test the expressions of BAX,Bcl-2,caspase-3 and PI3 K/m TOR/GSK3β proteins in the five groups. Results The AD model cells,over-expression and inhibition expression of MALAT1 vectors were successfully constructed. Inhibited expression of MALAT1 significantly inhibited the proliferation of AD SH-SY5 Y cells,promoted apoptosis and arrested cell cycle in G1 phase. Western blotting showed that the inhibited expression of MALAT1 up-regulated the expressions of BAX,caspase-3 and down-regulated the expression of Bcl-2. At the same time,the inhibited expression of MALAT1 significantly inhibited the expression of p-PI3 K/p-m TOR/p-GSK3β. In addition,over-expression of MALAT1 reversed the above effects. Conclusion Konck-down of MALAT1 can inhibit the proliferation and promote the apoptosis of AD model cel s via down-regulating the activity of PI3 K/m TOR/GSK3β.