| Background and ObjectiveAs the population aging speed up, the morbidity of coronary heart disease, hepertension,myocardial infarction is constantly increasing,the morbidity and mortality of heart failure increased continuously.Therefore,finding a series of biomakers which can both assist diagnosis diseases earlier and reflect the risk and prognosis of diseases is of important clinical significance.As the process of heart failure,there are a variety of structure changes,such as myocyte hypertrophy apoptosis, fibrosis,the reducing of capillary and the activation of the immune system etc.The changes of cardiac structure lead to cardiac dysfunction(such as ejection fraction reduced,filling pressure increased, etc.).However,potential molecular mechanisms have not been clarified.Micro RNAs(mi RNAs) are endogenous small RNAs which own 21-25 nucleotides in length.Recently,a large number of studies have shown that mi RNAs have been sensitive and specific biomarkers of various tissue injury and pathological conditions.Mi RNAs involve in myocardial remodeling by a variety of cardiac pathological changes and lead to heart failure eventually.Therefore, we can make a diagnosis by the levels of some specific mi RNAs.Our research include: 1) observate the expression of mi R-423,mi R-18 b and mi R-129 in serum of aged mice between the heart failure group and the control group by establishing aged mice with heart failure model.2) observate the expression of mi R-423 as the process of heart failure,discuss their relationship and provide value for the diagnosis or prognosis of heart failure. MethodsAccording to the method of coin,the 54 aged male and healthy mice was randomly divided into two groups.Heart failure group(n=38):conventional feeding and abdominal subcutaneous injection of isopropyl adrenaline(ISO) for 14 days to establish the heart failure mouse model.Control group(n=16):routine feeding and injection the equivalent saline for 14 days,then continue to feed conventionally for 4 weeks.2.Compare the cardiac function and heart rate by echocardiogram and electrocardiogram,kill 10 mice( heart failure group 4w),then return the heart specimens,weigh the whole heart and left ventricle finally calculate the left ventricular mass index(LVMI).Myocardial specimens were cutted for routine HE staining respectively,after fixation,dehydration and paraffin-embed.3.Continue to raise for two weeks then kill 10 mice(heart failure group 6w), then continue to raise for 2 weeks then kill the rest( heart failure group 8w). Collecting 4 ml blood by pressing the mouse eyes,collect the supernatant fluid after centrifugal.4.Mi RNAs was extracted from plasma and reverse-transcribed to complementary DNA.To obtain corresponding c DNA and take β-actin for internal calibration.We detect the expression of mi R-423,mi R-18 b and mi R-129 in mice with heart failure and normal mice through real-time fluorescent quantitative PCR(RT-PCR).5.We detect the expression of mi R-423 in serum of aged mice occurred in the process of heart failure through real-time fluorescent quantitative PCR(RT-PCR).6.Using SPSS 16.0 software package for data analysis, the count data uses mean+/-standard deviation( sx ±).If the measurement data meets the normality, use t-test;otherwise use the rank test.More groups compared with Kruskal-Wallis H test,the difference is statistically significant(P<0. 05).Results1.The left ventricular mass index(LVMI,mg/g):the control group is 2.68±0.32, heart failure group is 5.70±0.54.By contrast, left ventricular mass index of the heart failure group was obviously higher,the difference was statistically significant(P<0.01).2.HE staining: myocardial cell structure of the control group is complete, muscle fiber are arranged regularly;part of myocardial fiber fracture in the heart failure group, edema and hypertrophy occured in different degree, part of the myocardial cells show focal or extensive laminar necrosis.3.Echocardiography:in the heart failure group,chambers of the heart enlarged obviously,heart rate is rapid,left ventricular short axis has more obvious contraction dysfunction(P < 0.05).4.The electrocardiogram:compared with control group, the heart rate of mice in the heart failure group is faster,the difference was statistically significant(P<0.05).5.Expression of mi R-423,mi R-18 b,mi R-129:the expression of mi R-423 in mice with heart failure is significantly higher than control group(P<0.001),while the expression of mi R-18 b and mi R-129 are no statistically significant difference(P> 0.05).6.Expression of mi R-423 is on the rise in the process of heart failure, the difference was statistically significant(P<0.01). Conclusion1. Expression of mi R-423 is up-regulated in the mice with heart failure,while the expression of mi R-18 b and mi R-129 are no statistically significant.2.Expression of mi R-423 is on the rise in the process of heart failure.It may be as a potential new biomarkers in serum.It plays an important role in diagnosis and prognosis of heart failure in the future. |
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