title: Elimination of remaining undifferentiated induced pluripotent stem cells in the process of human cardiac cell sheet fabrication using a methionine-free culture condition.
abstract: Cardiac tissue engineering is a promising method for regenerative medicine. Although we have developed human cardiac cell sheets by integration of cell sheet-based tissue engineering and scalable bioreactor culture, the risk of contamination by induced pluripotent stem (iPS) cells in cardiac cell sheets remains unresolved. In the present study, we established a novel culture method to fabricate human cardiac cell sheets with a decreased risk of iPS cell contamination while maintaining viabilities of iPS cell-derived cells, including cardiomyocytes and fibroblasts, using a methionine-free culture condition. When cultured in the methionine-free condition, human iPS cells did not survive without feeder cells and could not proliferate or form colonies on feeder cells or in coculture with cells for cardiac cell sheet fabrication. When iPS cell-derived cells after the cardiac differentiation were transiently cultured in the methionine-free condition, gene expression of OCT3/4 and NANOG was downregulated significantly compared with that in the standard culture condition. Furthermore, in fabricated cardiac cell sheets, spontaneous and synchronous beating was observed in the whole area while maintaining or upregulating the expression of various cardiac and extracellular matrix genes. These findings suggest that human iPS cells are methionine dependent and a methionine-free culture condition for cardiac cell sheet fabrication might reduce the risk of iPS cell contamination.
authors.affiliation: 1 Institute of Advanced Biomedical Engineering and Science, Tokyo Women's Medical University , Tokyo, Japan .
authors.forename: Katsuhisa
authors.initials: K
authors.lastname: Matsuura
authors.forename: Fumiko
authors.initials: F
authors.lastname: Kodama
authors.forename: Kasumi
authors.initials: K
authors.lastname: Sugiyama
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Shimizu
authors.forename: Nobuhisa
authors.initials: N
authors.lastname: Hagiwara
authors.forename: Teruo
authors.initials: T
authors.lastname: Okano
mesh_terms: D018929:Cell Culture Techniques / Q000379:methods*; D002454:Cell Differentiation / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000166:cytology*; D008715:Methionine / Q000494:pharmacology*; D009206:Myocardium / Q000166:cytology*; D023822:Tissue Engineering
chemical_list: D008715:Methionine