title: Icariin-mediated modulation of cell cycle and p53 during cardiomyocyte differentiation in embryonic stem cells.
abstract: The aim of this study was to investigate the possible inducible effects and to clarify the modulation by icariin of cell cycle and p53 expression in the differentiation of embryonic stem cells into cardiomyocytes in vitro. Embryonic stem cells were cultivated as embryoid bodies in hanging drops and induced to differentiate into cardiomyocytes by icariin at 10(-7) M. Cardiomyocytes were characterized by the expression of sarcomeric proteins, alpha-actinin and cardiac troponin T, by immunocytochemistry. Flow cytometry revealed that 10(-7) M icariin treatment for 48 h significantly induced the accumulation of cells in G0/G1 and reduced the proportion of cells in S phase. A marked increase in apoptosis rate was observed 48 h after icariin treatment. Icariin resulted in significantly increased expressions of p53 mRNA and protein, as determined by reverse transcription-polymerase chain reaction and Western blot analysis. During day 7+0 and 7+9 cardiac developmental stage, 10(-7) M icariin increased the level of p53 mRNA, but caused a parallel decrease in the level of p53 protein. In conclusion, icariin at 10(-7) M facilitated the directional differentiation of embryonic stem cells into cardiomyocytes. Results showed p53 to be an important regulator in the differentiation in embryonic stem cells treated with 10(-7) M icariin, controlling or adjusting the balance between differentiated cells and cells undergoing apoptosis.
authors.affiliation: Department of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310031, China.
authors.forename: Danyan
authors.initials: D
authors.lastname: Zhu
authors.forename: Linhai
authors.initials: L
authors.lastname: Qu
authors.forename: Xiangnan
authors.initials: X
authors.lastname: Zhang
authors.forename: Yijia
authors.initials: Y
authors.lastname: Lou
mesh_terms: D000165:Acridine Orange; D000185:Actinin / Q000378:metabolism; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D002453:Cell Cycle / Q000187:drug effects*; D002454:Cell Differentiation / Q000187:drug effects*; D002460:Cell Line; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004622:Embryo, Mammalian / Q000166:cytology; D004996:Ethidium; D005419:Flavonoids / Q000494:pharmacology*; D005434:Flow Cytometry; D019084:Fluorescent Antibody Technique, Indirect; D015870:Gene Expression / Q000187:drug effects; D051379:Mice; D008856:Microscopy, Fluorescence; D032383:Myocytes, Cardiac / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013234:Stem Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D013997:Time Factors; D014212:Tretinoin / Q000494:pharmacology; D020107:Troponin T / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*
chemical_list: D005419:Flavonoids; D012333:RNA, Messenger; D020107:Troponin T; D016159:Tumor Suppressor Protein p53; D000185:Actinin; D014212:Tretinoin; D004996:Ethidium; D000165:Acridine Orange; C056599:icariin