Micro RNA在心肌梗死中课件.pptVIP

microRNA in Acute Myocardial Infarction 河北医科大学第三医院急诊科 董士民 dsm_123@163.com mirRNA are endogenous, noncoding,single-stranded RNAs of ~22 nucleotides and constitue a novel class of gene regulators Currently, about 600 mirRNAs have been cloned and seguenced in humans ,and the estimated number of mirRNA genes is as high as 1,000 in the human genoume Functionally, an individual miRNA is as important as a transcription factor because it is able to regulate the expression of its multiple target genes As a group,mirRNAs are estimate to regulate over 30% of the genes in a cell It is thus not surprising that mirRNAs are involved in the regulation of almost all major cellular fumctions including apoptosis and necrosis , which are two key cellular event in acute myocardial infarction(AMI) Several recent report have suggested that mirRNAS might play critical roles in the pathophysiology of AMI. Yang et al have found that the expression of a cardiac arrhythmia-related mirRNA, mirRNA-1 is increased in human hearts with coronary heart disease(CAD) and in rat hearts with AMI. The results of mirRNA-1 expression change in human hearts with CAD are still controversial, because another recent study has demonstrated that the mirRNA-1 expression tends to be downregulated in human hearts with CAD. The potential involvement of mirRNAs in AMI is also suggested in a study using mirRNA-126 null mice , in which Wang et al have found that the survival rate in mirRNA-126 deficient mice following AMI is significently reduced compared with that in wild-type mice. The expression signature in the late phase of AMI(3and 14days after AMI) has just been identified by an excellent study reported by van Rooij et al. mirRNA-29 plays an important role in cardiac fibrosis during the repair process after AMI. In an in vitro ischemia/reperfusion injury model, in mouse hearts pre-injected with heat-shock-induced mirRNAs including mirRNA-21,myocardial infarct size after I/R injury is