Effects of serum from myocardial infarction rats on rat bone marrow mesenchymal stem cell differentiation into cardiomyocytes / 中国组织工程研究

ABSTRACT

BACKGROUND: Differentiation of bone marrow mesenchymal stem calls(BMSCs) is associated with their microenvironment. After acute myocardial infarction (AMI), the necrosis of cardiomyocytes caused activation of complement, generation of free radical, and secretion of various cell factors. As a result, the ingredients of patients' serum also changed, so does the changes will influence the differentiation of BMSCs into cardiomyocytes? And what influence it will be? OBJECTIVE: To investigative effects of AMI rat serum on the differentiation of BMSCs into cardiomyocytes. DESIGN, TIME AND SETTING: The in vitro controlled cytology experiment was performed at the Laboratory of Center for Stem cells and Tissue Engineering, Sun Yat-sen University from September in 2005 to June in 2006. MATERIALS SPF Sprague Dawley rats, weighing 50-80 g, aged 3-4 weeks, were used for culture of BMSCs, and SpragueDawley rats, weighing 200-300 g, aged 6-8 weeks, were used for making AMI models. METHODS: BMSCs were isolated and cultured with the adherent method. After making AMI rat models by deligating anterior descending of the left coronary artery, the serum were collected and centrifuged from AMI and normal rats. Then the passage 3 of BMSCs were divided into six groups, non-induction group, 5-azacytidine (5-aza) group, 5-aza plus serum from AMI rat group, 5-aza plus serum from normal rat group, serum from AMI rat group, and serum from normal rat group. MAIN OUTCOME MEASURES: Morphology changes in rat BMSCs after induction; Expression of cardiac troponin T of BMSCs after induction; Expression of GATA-4 and desmin mRNA of BMSCs after induction. RESULTS: After being induced by 5-aza and two kinds of serum, some cells became elongated and thinner. Two to three weeks after induction, some cells had a ball-like or rod-like appearance, and connection were formed between adjacent cells. It showed that some BMSC have differentiated into cardiac like cells. The expression of cardiac troponin T, GATA-4 and desmin were positive in cells differentiated from BMSCs. The troponin T expression in control group and simple serum induction group were negative, but GATA-4 and desmin expressed weakly. CONCLUSION: Serum from AMI rat cannot induce BMSCs to differentiate into cardiomyocytes alone, but it promotes BMSCs induced by 5-aza differentiating into cardiomyocytes and facilitates the differentiated calls into mature.