title: KSR-based medium improves the generation of high-quality mouse iPS cells.
abstract: Induced pluripotent stem (iPS) cells from somatic cells have great potential for regenerative medicine. The efficiency in generation of iPS cells has been significantly improved in recent years. However, the generation of high-quality iPS cells remains of high interest. Consistently, we demonstrate that knockout serum replacement (KSR)-based medium accelerates iPS cell induction and improves the quality of iPS cells, as confirmed by generation of chimeras and all iPS cell-derived offspring with germline transmission competency. Both alkaline phosphatase (AP) activity assay and expression of Nanog have been used to evaluate the efficiency of iPS cell induction and formation of ES/iPS cell colonies; however, appropriate expression of Nanog frequently indicates the quality of ES/iPS cells. Interestingly, whereas foetal bovine serum (FBS)-based media increase iPS cell colony formation, as revealed by AP activity, KSR-based media increase the frequency of iPS cell colony formation with Nanog expression. Furthermore, inhibition of MAPK/ERK by a specific inhibitor, PD0325901, in KSR- but not in FBS-based media significantly increases Nanog-GFP+ iPS cells. In contrast, addition of bFGF in KSR-based media decreases proportion of Nanog-GFP+ iPS cells. Remarkably, PD can rescue Nanog-GFP+ deficiency caused by bFGF. These data suggest that MAPK/ERK pathway influences high quality mouse iPS cells and that KSR- and PD-based media could enrich homogeneous authentic pluripotent stem cells.
authors.affiliation: State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin, China.
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Ye
authors.affiliation: State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin, China.
authors.forename: Lingling
authors.initials: L
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin, China.
authors.forename: Jiao
authors.initials: J
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin, China.
authors.forename: Jingzhuo
authors.initials: J
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Liu
mesh_terms: D000818:Animals; D002417:Cattle; D018929:Cell Culture Techniques / Q000379:methods*; D002478:Cells, Cultured; D003470:Culture Media / Q000378:metabolism*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D057026:Induced Pluripotent Stem Cells / Q000166:cytology* / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000187:drug effects; D051379:Mice; D008810:Mice, Inbred C57BL; D044967:Serum / Q000378:metabolism
chemical_list: D003470:Culture Media; D048049:Extracellular Signal-Regulated MAP Kinases