The Temporal Expressions Of The Transcription Factors And Target Genes And Mechanism Of Histone Acetylation In Cardiomyocyte Hypertrophy

Objective To investigate the temporal expression patterns of related genes in cardiomyocyte hypertrophy,and to compared with the patterns related to the development of heart to provide the clues of mechanism research and further therapy.Method Hypertrophy in neonatal mice ventricular myocytes was induced by isoproterenol(ISO).The viability of cardiomyocyte was detected by CCK-8,the average diameters were measured by computer photograph analysis system.Cardiomyocyte were subjected to immunocytochemistry using the primary antibody against cardiac MHC and the cell-surface area was measured by computer photograph analysis system.The mRNA and protein expression levels of related genes were respectively measured by RT-PCR and Western Blot.Results The viability of cardiomyocyte treated by different concentrates of ISO was no difference compared with control group(P<0.05).The cell-surface area and the cell volume were increased significantly compared with control group(P<0.05).The model of cardiomyocyte hypertrophy stimulated by ISO was constructed successfully.The expression levels of GATA4,MEF2 C,GATA5,BNP and ANP were increased after 24 hours treatment,those of P300,α-MHC,TBX5 were increased after 12 hours treatment and those of SRF,β-MHC were increased after 6 hours treatment(P<0.05).The expression levels of related genes including GATA4,P300,MEF2 C,ANP,BNP,SRF were firstly increased and then decreased in cardiomyoctye induced by ISO.The expression levels of GATA4,P300,MEF2 C,ANP,BNP,SRF were higher than those of control group(P<0.05)and the expression of MEF2 C decreased to be normal after 72h’s treatment(P>0.05).The expressions of GATA5,TBX5,ANP,BNP maintained the rising tendence(P<0.05).There was no difference of NKX2.5 among the different time points(P>0.05).The expression of GATA4 protein was increased and the expression of HEY2 protein decreased after 48h’s treatment(P<0.05).Conclusion The model of cardiomyocyte hypertrophy stimulated by ISO was constructed successfully according to the results of the viability and cell-surface area and volume of primary cardiomyocyte.In hypertrophic cardiomyocytes,the expression pattern of MEF2 C is similar to the pattern in the development of heart,but the expression patterns of GATA5,GATA4,TBX5,SRF are different with those in the development of heart,which implies these gene are important during process from compensatory stage to decompensated stage.The expression patterns of GATA4,MEF2 C,SRF are similar with the pattern of P300,which implies the temporal expressions could be regulated by P300.