The Expression Of MicroRNA-21 In Hypertrophic Heart And Fibrotic Kidney From Spontaneously Hypertensive Rat

ObjectiveCardiovascular disease has long been the leading cause of death in developed countries,and it is rapidly becoming the number one killer in developing countries.Cardiac hypertrophy,the common pathological response to a number of cardiovascular diseases such as hypertension,ischemic heart disease,valvular diseases,and endocrine disorders,is a major determinant of mortality and morbidity in cardiovascular diseases.The pathological process of the heart is associated with altered expression profile of genes that are important for cardiac function。MicroRNAs(miRNAs) are a recently discovered class of endogenous,small,noncoding RNAs that regulate gene expression.Their biological importance,initially demonstrated in cancer,viral diseases and developmental processes,was more recently investigated in cardiovascular physiology and pathology.A full range of miroRNAs is expressed in heart muscle, and theirmisregulation alone or in association affects cell fate,regulates the balance between cell proliferation and differentiation, and induces or influences heart diseasestates, such as hypertrophy, fibrosis, electrical remodeling and arrhythmiaUp-or downregulation of several microRNAs accompanied pathological cardiac remodeling in rodents and humans Roles in cardiac growth were found for miR-195,miR-21, miR-133, and miR-l.The toppest point is miR-21,. Many studies have consistent result obtained that MiR-21 is upregulated in hypertrophic hearts.In this study,we want to identify the expression of miR-21 in heart and kidney tissues from SHR rats and wistar rats by using pathological staining and real time pcr and to investigate the mechanism the of microRNA-21 in hypertrophic left ventricle induced by hypertension and fibrotic renal cortical tissue.Methods1. Model preparationWe applied a well-established SHR model as experimental groups.Age-matched wistar rats will be used as control groups.Both groups were fed with standard rat fodder.Experimental group,0.45%sodium chloride solution be kept for 3 weeks. Normal control rats drinked tap water. Breeding animals were sacrificed after four weeks.Kidney and left ventricle were obtained immediately at-80℃for preservation.2. Evaluation of Cardiac Hypertrophy and renal fibrosisCardiac hypertrophy was evaluated by histopathological analysis of heart size and the ratio of left ventricle weight to body weight (LVW:BW).Renal fibrosis was evaluated by histopathological analysis.3. MiRNA detection(1) Extraction of miRNA(2) Detect the concentration and purity (OD260/280,the range of 1.7-2.0) of miRNA solutions.(3) Add Poly(A)tail(4) Reverse transcription(5) PCRResults1. Cardiac hypertrophy and renal fibrosis were sucessfully. constr ucted.All animals were killed at 15 weeks of age.Compared with the control group,left ventricular hypertrophy in experimental group was obvious visiually.From pathological sections, We can see the degree of the left ventricular hypertrophy,myocardial fibrosis and renal fibrosis are more obvious in experimental group,compared with the control group.The value of the LVMI in the experimental group is bigger than that in the control group. 2. Expression of microRNA-21 in hypertrophic heart and fibrotic kidney.The expression of microRNA-21 in the left ventricle and proximal renal medullary cortex were higher in experimental group, the differences were significantly. (p<0.05)ConclusionThe expression of miR-21 in hypertrophic heart and proximal renal medullary cortex of SHR were relatively higher. MiR-21 may be involved in the pathological processes of hypertensive cardiac hypertrophy and renal fibrosis.