Role of transfected angiotensinⅡ receptor anti-sense nucleotide in the growth of cardiomyocytes / 第三军医大学学报

ABSTRACT

Objective　To evaluate the role of transfected angiotensinⅡ(Ang Ⅱ) receptor AT1 anti-sense nucleotide (AT1A) in the expression of subtypes of AngⅡ receptor mRNA, synthesis of protein and nucleic acid in cardiomyocytes. Methods　AT1 cDNA sequence (476 bp) was cloned with RT-PCR and reversely inserted into PcDNA3.1 (5.4 kb) to construct an intact plasmid containing AT1A (PAT1A). The plasmid was then transfected into the cultured cardiomyocytes and identified with RT-PCR and Western blot. The synthesis of protein and nucleic acid identified by 3H-Leu and 3H-TdR incorporation, and expressions of AT1 and AT2 mRNA by RT-PCR, were compared between transfected and nontransfected cardiomyocytes after being stimulated with 10-7 mol/L AngⅡ for 24 h. Results　The plasmid PAT1A were successfully constructed. The AT1 mRNA and its protein were expressed significantly less in the transfected cardiomyocytes than in the control (P<0.01). In the transfected cardiomyocytes, AT1 mRNA expression was markedly decreased, but that of AT2 mRNA obviously increased (P<0.01) when compared with the nontransfected cardiomyocytes after stimulation for 24 h with AngⅡ 10-7 mol/L; no significant difference was found in 3H-Leu and 3H-TdR incorporation between them. Conclusion　After the cardiomyocytes was tranfected with AT1A, the expression of AT1 mRNA was markedly suppressed，while AT2 mRNA up-regulated at the same time. Our results indicate that AT1A blocking can not effectively interrupt the Ang Ⅱ-induced synthesis of the protein and nucleic acid in cardiomyocytes.