| Objective Diabetic cardiomyopathy(DCM)is an independent and specific diabetic complication,and its mainly pathological change is myocardial fibrosis and abnormal glucose metabolism?Previous studies has shown that in the progress of myocardial fibrosis,collagen synthesis and deposition is one of the main causes of fibrosis.It has been reported that high glucose can accelerate the production of collagen,then increasing the degree of fibrosis,thereby cause myocardial damage.micro RNA is a type of non-coding small fragment RNA that can participate in post-transcriptional translation by binding to specific regions of the target gene messenger RNA,and has biological functions such as regulating cell proliferation,canceration,and apoptosis.This project will start with diabetic cardiomyopathy,observe the expression of miR-152 in myocardial fibroblasts,explore its role in regulate myocardial fibrosis,and provide new drug targets for the prevention and treatment of diabetic cardiomyopathy.Methods Animal experiment: Forty rats were randomly divided into a control group and a diabetes group,with 20 rats in each group.The diabetic group was injected with150 mg / kg streptozotocin(STZ)intraperitoneally once,3 days and 7 days after injection,blood was collected through the tail vein of the rat to measure blood glucose,if both blood glucose were 11.1 mm / L,the rat is considered to be a successful model.Control group was injected with the same amount of normal saline.After 12 weeks of conventional breed,the rats were sacrificed after anesthesia,and the heart of the rats was dissected out,paraffin myocardial tissues and fixed with paraformaldehyde,tissues taken and grouped for HE and Masson staining to observe the degree of myocardial tissue and myocardial fibrosis.Protein and RNA were extracted from the remainingmyocardial tissues.Western blot was used to detect the expression of ?-smooth muscle actin(?-SMA)and collagen type ?(collagen ?)in each group.q PCR was used to detect miR-152 in each group.Cell experiments: Cardiac fibroblasts(CFs)were extracted from neonatal rats.Cardiac fibroblasts were transiently transfected with miR-152 mimics,miR-152 empty plasmid,and miR-152 negative control.At the same time,some myocardial fibroblasts were taken for high glucose culture.The m RNA expressions of miR-152,Collagen I,and ?-SMA were detected by q PCR,and the expressions of Collagen I and ?-SMA proteins were detected by Western blot.MTT assay was used to detect the activity of cardiac fibroblasts.Results Animal experiment: Compared with the control group,in the diabetic group,HE and Masson staining showed that the myocardial cells were arranged disorderly,collagen increased significantly,and the cell volume increased,suggest that the model was successful.At the same time,q PCR showed that the m RNA expression of miR-152 in the diabetic group was significantly lower than that in the control group.Western blot showed that the expressions of ?-SMA and Collagen ? protein were higher than those of the control group.Cell experiments: q PCR and Western blot showed that m RNA of miR-152 in the high glucose group was lower than that in the control group.The expression of miR-152 in the miR-152 mimics group was significantly higher than that in the negative control group and the blank control group,and the expressions of ?-SMA and Collagen ? protein were significantly lower than those in the negative control group and the blank control group.MTT test results showed that the proliferation of myocardial fibroblasts in the miR-152 mimics group was significantly lower than that in the blank control group and the negative control group.Conclusion In summary,the high expression of miR-152 can reduce the expression of related myocardial fibrosis proteins such as ?-SMA and Collagen ?,thereby inhibite the occurrence of myocardial fibrosis.And provide new ideas to prevent myocardialfibrosis and delay the progress of its related diseases,such as diabetic cardiomyopathy,and even to reverse its pathological changes. |
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