The temporal expression patterns of the transcription factors and target genes in cardiomyocyte hypertrophy / 解放军医学杂志

ABSTRACT

Objective To investigate the temporal expression patterns of the related transcription factors and target genes in cardiomyocyte hypertrophy,and provide valuable clues for further researches on cardiomyocyte hypertrophy.Methods Isoproterenol (ISO) was used to induce ventricular myocytes hypertrophy in neonatal mice.The survival rate of cardiomyocyte was detected by CCK-8,and the average diameters and surface areas of cells were measured by computer photograph analysis system.The mRNA and protein expression levels of related genes were respectively measured by RT-PCR and Western blotting.Results The model of cardiomyocyte hypertrophy stimulated by ISO was constructed successfully.The expression levels of GATA4,MEF2C,GATA5,BNP and ANP increased 24 hours after ISO treatment,the expression levels of P300,α-MHC and TBX5 increased 12 hours after ISO treatment,and of SRF and β-MHC mRNA increased 6 hours after ISO treatment (P＜0.05).The expression levels of GATA4,α-MHC,β-MHC,SRF and P300 mRNA increased firstly,and then decreased in cardiomyocytes induced by ISO.The expression levels of GATA4,SRF,α-MHC,β-MHC and P300 mRNA were still higher than normal (P＜0.05),but of MEF2C decreased to normal (P＞0.0S) 72 hours after ISO treatment.The expression levels continuously elevated of GATA5,TBX5,ANP and BNP mRNA than that of controls (P＜0.05),while no fluctuation was found in NKX2.5 mRNA expression (P＞0.05).The expression of GATA4 protein increased,while of HEY2 protein decreased 48 hours after ISO treatment (P＜0.05).Conclusions In hypertrophic cardiomyocytes,the expression pattern of MEF2C is similar to,but the patterns of GATA5,GATA4,TBX5 and SRF are different with that in the development of heart,implying these genes are important during the process from compensatory stage to decompensation stage.The expression patterns of GATA4,MEF2C and SRF are similar to that of acetylase P300,implying the temporal expressions could be regulated by P300 in cardiomyocyte hypertrophy.