Study On The Expression Changes Of LncRNA-MEG3 In Myocardial Fibrosis And Activation And Proliferation Of Myocardial Fibroblasts

Objective Myocardial fibrosis is the pathological manifestation of most advanced heart diseases.Increased proliferative activity of myocardial fibroblasts(CFs)is the main cause of myocardial fibrosis,manifested by increased production of extracellular matrix(ECM)such as collagen molecules in myocardial tissue.It has been proved that LncRNA-MEG3 can inhibit the growth and migration of tumor cells in tumors.At the same time,it is reported in the literature that MEG3 is also involved in the regulation of organ tissue fibrosis.Therefore,this study established a rat myocardial tissue fibrosis model and cell-level fibrosis.Model to study the expression changes of MEG3 in the process of rat myocardial fibrosis and CFs activation and proliferation,in order to explore the possible role and significance of MEG3 in myocardial fibers.Methods Thirty SD male rats under the same conditions were divided into two groups.One group was injected with isoproterenol(ISO)5 mg/kg subcutaneously into the abdomen to construct a myocardial fibrosis animal model;the remaining group was given the same conditions every day The normal control group was injected with 10ml/kg physiological sodium chloride solution.After two consecutive injections,the two groups of rats were killed by spinal dislocation and the heart specimens were dissected.After making the heart tissue slices,HE and Masson staining were performed,and the pathological changes of the rat myocardial tissue were observed with a microscope,and then the collagen fraction of the myocardial tissue in the slices was calculated.The total protein and total RNA of rat myocardial tissue in the animal model of myocardial fibrosis were extracted,and then Western blotting and q RT-PCR were used to detect α-smooth muscle actin(α-SMA)and type I collagen molecules(Collagen I).The expression of protein and mRNA levels,and the expression changes of MEG3 in the myocardial tissues of the two groups of rats.The CFs of suckling mice were extracted and divided into two groups for culture.One group was treated with transforming growth factor-β1(TGF-β1)for 48 hours to construct a myocardial fibrosis cell model group;the other group was cultured and grown under the same conditions without TGF-β1.It is a blank control group.After culturing for 48 hours,the total protein and total RNA of the two groups of CFs were extracted,and then Western blotting and q RT-PCR were used to detect the relative expression of α-SMA and Collagen I at the protein and mRNA levels,and MEG3 in the two groups of CFs.The expression changes.At the same time,the CCK-8 method was used to detect the changes in cell viability of the two groups of CFs cells after 48 hours of culture.Results In the ISO-induced myocardial fibrosis animal model,HE and Masson staining indicated that compared with the normal control group,the myocardial cells of the ISO model group were larger in volume,irregular in shape,more intercellular substance,significantly increased collagen,and increased collagen fraction.;Western blotting results indicated that the expression of α-SMA and Collagen I protein molecules are significantly increased compared with the normal control group;q RT-PCR results indicated that the expression of α-SMA and Collagen I mRNA was significantly increased compared with the normal control group,while the MEG3 gene expression was reduced.In a fibrotic cell model in which TGF-β1 stimulated the activation and proliferation of CFs cells,the CCK-8 experiment results suggested that the OD values of CFs stimulated by TGF-β1 for 24 h and 48 h are significantly higher than those of the blank control CFs,indicating cell proliferation activity Significantly enhanced;Western blotting results suggested that the expression of α-SMA and Collagen I protein molecules in the cell model group that induced CFs by TGF-β1stimulation was significantly higher than that in the blank control group that was not given TGF-β1 stimulation.The q RT-PCR results also suggested that the expression ofα-SMA and Collagen I protein molecules in the cell model group that were not given TGF-β1 stimulation was significantly increased.The expression of α-SMA and Collagen I mRNA in the blank control group not given TGF-β1 induction stimulation increased significantly,while the expression of MEG3 gene decreased significantly.Conclusion The expression of LncRNA-MEG3 in rat myocardial fibrosis tissue and activation and proliferation of CFs cells is significantly reduced,suggesting that LncRNA-MEG3 may play a negative regulatory role in the process of rat myocardial fibrosis and activation and proliferation of myocardial fibroblasts.This experiment provides new ideas for clinical research on prevention and treatment of myocardial fibrosis...