Effect Of LncMALAT1 On The Proliferation And Differentiation Of Human Lung Fibroblasts Induced By Transforming Growth Factor-β1

Background and ObjectiveIdiopathic pulmonary fibrosis(IPF)is the most common idiopathic interstitial pneumonia.Its prognosis is worse than that of most lung cancer.The median survival time is 2-5 years since the date of diagnosis,and the 5-year survival rate is only 20%.Its morbidity has been rising in recent decades and there is no cure for it.Long non-coding RNA(lncRNA)metastasis-associated lung adenocarcinoma transcript 1(MALAT1)is a widely expressed lncRNA that can promote the proliferation,migration and invasion of various tumor cells and participate in the progression of liver fibrosis.However,there has not been any research on the role of lncRNA MALAT1 in IPF.The proliferation and differentiation of lung fibroblasts into myofibroblasts is one of the key processes that affect the occurrence of IPF.For this reason,in this study,the role of lncRNA MALAT1 in the proliferation and differentiation of human lung fibroblasts was studied.Human lung fibroblasts HFL-1 was cultured,the effects of different concentrations of transforming growth factor-β1(TGF-β1)acted on different time points on the proliferation of HFL-1 cells were detected by methyl thiazolyl tetrazolium(MTT)assay,and the optimal concentration and time of TGF-β1 were determined.On the basis of the above experiments,HFL-1 cells were treated with 5ug/L TGF-β1 for 48 h,which was defined as the drug group,and cells without any treatment were defined as the control group.Used the real-time quantitative PCR detecting system(qPCR)to detect the expression level of lncMALAT1 in the two groups.The HFL-1 cells were divided into four groups:the blank control group,TGF-β1 group,negative transfection group and siMALAT1 group.The blank control group didn’t receive any treatment,the TGF-β1 group was treated with TGF-β1 of 5ug/L,the negative transfection group was treated with TGF-β1 and siMALAT1 NC,while the siMALAT1 group was treated with TGF-β1 and siMALAT1.QPCR was used to detect the expression level of α-smooth muscle activation protein(α-SMA),collagen1(COL1)mRNA and lncMALAT1 in different groups.The expression of α-SMA and COL1 protein in the above four groups was detected by Western-blot,and the proliferation of HFL-1 in the four groups was detected by MTT.Results(1)At 24 h,48 h and 72 h,the proliferation of HFL-1 stimulated by different concentrations of TGF-β1 showed a tendency of increasing first and then decreasing(P>0.05).When treated with TGF-β1 for 48 h,the cell proliferation activity was different among different concentration groups(P<0.05).The optimal concentration and time of TGF-β1 was 5ug/L for 48 h.(2)The relative expression of lncMALAT1 in drug group was higher than that in the control group(P<0.05).(3)The relative expression level of α-SMA,COL1 mRNA and lncMALA were significantly different among the four groups(P<0.05).The relative expression of RNA in TGF-β1 group and the negative transfection group was higher than that in blank control group and siMALAT1 group(P<0.05).The relative expression of RNA in the negative transfection group was not significantly different from that in the TGF-1 group(P>0.05).(4)The relative expression level of α-SMA and COL1 protein in the four groups were statistically different(P<0.05).The relative expression of protein in TGF-β1 group and negative transfection group was higher than that in the blank control group and siMALAT1 group(P<0.05),but there was no difference between the negative transfection group and TGF-β1 group(P>0.05).(5)There was statistical difference in the proliferative activity of HFL-1 among the four groups(P<0.05).The proliferative activity of HFL-1 in the TGF-β1 group and negative transfection group was higher than that in the blank control group and Materials and methods siMALAT1 group(P<0.05),and there was no difference between the negative transfection group and TGF-β1 group(P>0.05).Conclusion(1)The expression of lncMALAT1 increased after TGF-β1 stimulated HFL-1 cells.(2)After silenced lncMALAT1,the mRNA and protein expression level of α-SMA and COL1 in human lung fibroblasts activated by TGF-β1 decreased.(3)Silencing lncMALAT1 gene can inhibit the proliferation of human lung fibroblasts.(4)In-depth exploration of the mechanism,molecular pathways and targeted regulation of lncMALAT1 may provide a new therapeutic method for the treatment of IPF.