mRNA expression of connectin 43 and connectin 45 following transplantation of allogenic bone marrow mesenchymal stem cells in rats with acute myocardial infarction / 中国组织工程研究

ABSTRACT

BACKGROUND:Cell transplantation can repair damaged myocardial tissue.However,whether transplaned cells and host cells formed an effective electricity and mechanical couple or whether reconstruction of connexin (Cx) and arrhythmia formed,are still unclear.OBJECTIVE:It is hypothesized that arrhythmia can be treated by changing Cx levels and intervening abnormal GJ channel.Moreover,to explore the effects of bone marrow mesenchyma stem cells (MSCs) on the expression of Cx43 and Cx45 in rata with myocardial infarction.DESIGN,TIME AND SETTING:The randomized controlled animal study was performed at the Experimental Center,Guangxi Medical University from January 2008 to May 2009.MATERIALSA total of 180 Wistar rats were randomly divided into four groupsnormal control,sham operation,myocardial infarction,and MSCs,with 45 animals in each group.Each group was then divided into 3 subgroups (n=15) according to 4 weeks,8 weeks and 12 weeks post-transplantation.Additional 20 healthy,Wistar rats,aged 1 month,were selected to harvest MSCs.METHODS:The third passage of MSCs was induced by 5-aza like cardiomyocytes for 4 weeks,labeled with DAPI at 2 hours before transplantation.Models of acute myocardial infarction were established in all groups except sham operation group.At day 7 after model preparation,2×10~(10) /L MSCs were infused into the edge and center of myocardial infarcted region by multipoint injection.Rats in the myocardial infarction group were subjected to an equal volume of saline as wall as those in the normal control and sham operation groups.MAIN OUTCOME MEASURES:The mRNA expressions of Cx43,Cx45 were assayed by fluorescence quantitative PCR.RESULTS:The mRNA expression of Cx43 among each groups had no difference at weeks 4,8 and 12 after intervention in the normal areas.Compared to the normal areas,Cx43 mRNA reduced significantly at ischamic zone in the myocardial infarction group and MSCs group (P＜0.01),with notably increased of Cx45 mRNA expression (P＜0.01).Compared to myocardial infarction group,Cx43 mRNA expression was statistically higher in the MSCs group at the same points (P ＜ 0.01),and the Cx45 mRNA dramatically declined (P ＜ 0.01).CONCLUSION:Acute myocardial infarction reduces the mRNA expression of Cx43 and increases the Cx45 mRNA expression.The exogenous cells transplantation can upturn the mRNA expression of Cx43 in the border-zone of the infarcted area,and down-regulate the Cx45 mRNA expression in the border-zone of the infarcted area.