Abstract: 【Abstract】　Objective　To explore the effect of p53modRNA on promoting the maturation of early cardiomyocytes derived from human pluripotent stem cells. Methods　The early cardiomyocytes derived from human induced pluripotent stem cells were treated with p53 modRNA. The expression of cardiomyocyte maturation related gene mRNA was detected by qRT-PCR, the expression of cardiomyocyte maturation related protein was detected by Western blot, and the morphology and sarcomere development of cardiomyocytes were observed by cell immunofluorescence staining. Results　The results of qRT-PCR showed that after p53 modRNA treatment, the expression of cardiomyocyte proliferation-related genes decreased, the level of lipid metabolism increased, and the expression of myocardial specific genes increased, suggesting that the intracellular structure of cardiomyocytes may be more mature. The results of Western blot showed that the expression of cTnI protein in the transfeetion group was higher than that in the non-transfection group. The results of immunofluorescence staining showed that compared with the non-transfection group, the morphology of cells in the transfection group tended to be long rod type, and the sarcomere of cardiomyocytes was arranged more neatly and abundantly, which was closer to the morphology of mature cardiomyocytes. Conclusion　Early cardiomyocytes derived from human pluripotent stem cells treated with p53 modRNA can improve the related indexes of cell maturation to some extent.

Key words: 【Key words】　Cardiomyocytes, 　Maturation, 　Stem cells, 　Cell cycle