Effect of miRNA-933 on the apoptosis and proliferation of LX-2 cells and its molecular mechanism
Objective To investigate the regulatory effect of miRNA-933 on the apoptosis and proliferation of human hepatic stellate cell line LX-2 and its mechanism.Methods Firstly,with human liver tissue for research,gene microarray technology was used to detect the differentially expressed genes in liver tissue between liver cirrhosis/chronic hepatitis B tissue and normal liver tissue,among which the significantly differentially expressed miRNAs were identified,and thus miRNA-933 was determined as the research object.Then,with the human hepatic stellate cell line LX-2 for research,miRNA-933 mimic and inhibitor(miRNA-933 siRNA)were used to construct the LX-2 models of overexpression and knockdown,and the cells transfected with mimic-NC(overexpression)or siRNA-NC(knockdown)were established as the negative control group.Quantitative real-time PCR and Western blot were used to measure the expression levels of miRNA-933 and activation biomarkers;techniques such as cell proliferation assay and flow cytometry were used to investigate the effect and mechanism of miRNA-933 on cell apoptosis,proliferation,and activation.The independent-samples t test was used for comparison of continuous data between two groups;a one-way analysis of variance was used for comparison between multiple groups,and Bonferroni correction was also performed.Results A total of 18 significantly differentially expressed miRNAs were obtained based on the results of gene microarray,among which miRNA-933 was significantly downregulated(P<0.05).After LX-2 cells were transfected with miRNA-933 mimic or siRNA,compared with the negative control group,miRNA-933 siRNA significantly downregulated the expression of miRNA-933(P=0.000 7),while miRNA-933 mimic significantly upregulated the expression of miRNA-933(P=0.000 3).Western blot and quantitative real-time PCR showed that miRNA-933 siRNA significantly upregulated the expression of collagen Ⅰ and α-SMA(P<0.001),while miRNA-933 mimic significantly inhibited the expression of collagen Ⅰ and α-SMA(P<0.05).Flow cytometry showed that compared with the negative control group,miRNA-933 siRNA significantly downregulated the apoptosis rate of LX-2 cells(P=0.031 9),and miRNA-933 mimic significantly upregulated the apoptosis rate of LX-2 cells(P=0.005 5).Western blot showed that compared with the negative control group,miRNA-933 siRNA could inhibit the expression of Caspase-3(P=0.006 7)and poly(ADP-ribose)polymerase-1(PARP-1)(P=0.003 0)and upregulate the expression of B-cell lymphoma-2(Bcl-2)in LX-2 cells(P=0.002 0),while miRNA-933 mimic could significantly upregulate the expression of Caspase-3(P=0.011 8)and PARP-1(P=0.049 5)and downregulated the expression of Bcl-2(P=0.002 1).Cell proliferation assay showed that compared with the negative control group,miRNA-933 siRNA could promote the proliferation of LX-2 cells(P=0.011 5),while on the contrary,miRNA-933 mimic could inhibit the proliferation of LX-2 cells(P=0.001 2).Western blot and quantitative real-time PCR showed that miRNA-933 siRNA significantly inhibited the expression of Kruppel-like factor 6(KLF6)and downregulated the expression of activating transcription factor 4(ATF4),activating transcription factor 3(ATF3),and C/EBP homologous protein(CHOP),while miRNA-933 mimic promoted the expression of the above proteins(all P<0.05).Conclusion This study shows that miRNA-933 may promote cell apoptosis and inhibit cell activation and proliferation by promoting the activation of the KLF6/ATF4/ATF3/CHOP/Bcl-2 signal axis in LX-2 cells.
国家科技期刊平台
NSTL
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