ABSTRACT
Background and Objectives@#Manipulating different signaling pathways via small molecules could efficiently inducecardiomyocytes from human induced pluripotent stem cells (hiPSC). However, the effect of transcription factors on the hiPSC-directed cardiomyocytes differentiation remains unclear. Transcription factor, p53 has been demonstrated indispensable for the early embryonic development and mesendodermal differentiation of embryonic stem cells (ESC).We tested the hypothesis that p53 promotes cardiomyocytes differentiation from human hiPSC. @*Methods@#and Results: Using the well-characterized GiWi protocol that cardiomyocytes are generated from hiPSC via temporal modulation of Wnt signaling pathway by small molecules, we demonstrated that forced expression of p53 in hiPSC remarkably improved the differentiation efficiency of cardiomyocytes from hiPSC, whereas knockdown endogenous p53 decreased the yield of cardiomyocytes. This p53-mediated increased cardiomyocyte differentiation was mediated through WNT3, as evidenced by that overexpression of p53 upregulated the expression of WNT3, and knockdown of p53 decreased the WNT3 expression. Mechanistic analysis showed that the increased cardiomyocyte differentiation partially depended on the amplified mesendodermal specification resulted from p53-mediated activation of WNT3-mediated Wnt signaling. Consistently, endogenous WNT3 knockdown significantly ameliorated mesendodermal specification and subsequent cardiomyocyte differentiation. @*Conclusions@#These results provide a novel insight into the potential effect of p53 on the development and differentiation of cardiomyocyte during embryogenesis.
ABSTRACT
OBJECTIVE:To study the bacterial endotoxin test for cefotaxime sodium injection METHODS:Detection was carried out according to the principle and procedure in Chinese Pharmacopeia,2000 edition RESULTS:Cefotaxime did not interfere with limulus agent in maximal effective diluted concentration CONCLUSION:Bacterial endotoxin test could be used to replace the pyrogen test which is set in departmental standard
