Role Of Micro RNA-21 In The Regulation Of MMP-2 And MMP-9 In Sepsis And Molecular Mechanism

PartⅠThe Expression of MicroRNA-21,MMP-2 and MMP-9 in Plasma of Sepsis Patients and Their Correlation AnalysisObjective: To investigate the expression of microRNA-21,matrix metalloproteinase-2(MMP-2)and MMP-9 in plasma of sepsis patients and their correlation analysis.Provide theoretical and experimental basis for exploring new targets for diagnosis and treatment of sepsisMethods: Differentially expressed miRNAs were screened by statistically significant(P < 0.05)and differential folds(> 2)by searching the GEO database for sepsis-related data sets.The expression levels of miR-21,MMP-2 and MMP-9 in the serum of sepsis group and health group were detected by real-time fluorescence quantitative PCR and ELISA.Pearson correlation was used to analyze the correlation between miR-21,MMP-2 and MMP-9.Results: The final data set was GSE94717,and the eligible differentially expressed miRNA was miR-21(P<0.05).The expression levels of miR-21,MMP-2 and MMP-9 in the serum of sepsis group were higher than those in the control group,and there was a positive correlation between them(P < 0.05).Conclusion: The levels of plasma microRNA-21,MMP-2 and MMP-9 in sepsis group were higher than those in the healthy control group,and there was a positive correlation between them.Part Ⅱ Regulation and Mechanism of miR-21 on the Expression of MMP-2 and MMP-9 in RAW264.7 Cells Induced by LipopolysaccharideObjective: To investigate the influence and mechanism of miR-21 on the expression of matrix metalloproteinase-2(MMP-2)and matrix metalloproteinase-9(MMP-9)stimulated by LPS in RAW264.7,and further study the role and mechanism of miR-21 in sepsis.Methods: RAW264.7 cells were stimulated with 10mg/ml LPS for 24 hours.The expression levels of miR-21,MMP-2 and MMP-9 in LPS group and control group were detected by real-time fluorescence quantification PCR and ELISA.Pearson correlation was used to analyze the correlation between miR-21,MMP-2 and MMP-9.RAW264.7 cell model interfered by exogenous miR-21 and stimulated by LPS was established.The effects of miR-21 on the expression of MMP-2,MMP-9 and TIMP-3 protein were detected by Western blot.Results: The expression levels of miR-21,MMP-2 and MMP-9 in LPS group were higher than those in the control group,and there was a positive correlation between two group(P<0.05).Exogenous up-regulation of miR-21 increased the expression of MMP-2 and MMP-9,whereas decreased TIMP-3 expression(P<0.05);on the contrary,inhibition of miR-21 decreased the expression of MMP-2 and MMP-9,while increased TIMP-3(P < 0.05).Conclusion: miR-21 can promote the expression of MMP-2 and MMP-9 in RAW264.7 cells,and the mechanism may be related to the inhibition of targeting TIMP-3.