title: Distinct regulation of mitogen-activated protein kinase activities is coupled with enhanced cardiac differentiation of human embryonic stem cells.
abstract: Improving cardiac differentiation of human pluripotent stem cells is mandatory to provide functional heart muscle cells for novel therapies. Here, we have investigated the enhancing effect of the small molecule SB203580, a p38 MAPK inhibitor, on cardiomyogenesis in hESC by monitoring the phosphorylation patterns of the major MAPK pathway components p38, JNK and ERK by western immunoblotting. A remarkable drop in phosphorylation levels of all three MAPK pathways was induced after overnight embryoid body (EB) formation. Upon further differentiation, phosphorylation dynamics in EBs were specifically altered by distinct inhibitor concentrations. At 5μM of SB203580, cardiomyogenesis was most efficient and associated with the expected p38 pathway inhibition. In parallel, JNK activation was observed suggesting a regulatory interlink between these pathways in hESC ultimately supporting cardiac differentiation. In contrast, moderately elevated SB203580 concentrations (15-30μM) resulted in complete disruption of cardiomyogenesis which was associated with prominent inhibition of ERK and further elevated JNK activity. We propose that a tightly-balanced pattern in MAPK phosphorylation is important for early mesoderm and subsequent cardiomyocyte formation. Our data provide novel insights into molecular consequences of small molecule supplementation in hESC differentiation, emphasizing the role of MAPK-signaling.
authors: Bioprocessing Technology Institute, A*STAR (Agency for Science, Technology and Research), 20 Biopolis Way, #06-01, 138668 Singapore. kempf.henning@mh-hannover.de
authors: Henning
authors: H
authors: Kempf
authors: Marti
authors: M
authors: Lecina
authors: Sherwin
authors: S
authors: Ting
authors: Robert
authors: R
authors: Zweigerdt
authors: Steve
authors: S
authors: Oh
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D003470:Culture Media / Q000494:pharmacology; D058732:Embryoid Bodies / Q000166:cytology / Q000378:metabolism; D053595:Embryonic Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology*; D004789:Enzyme Activation / Q000187:drug effects; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000187:drug effects; D008648:Mesoderm / Q000187:drug effects / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D008954:Models, Biological; D009206:Myocardium / Q000166:cytology* / Q000201:enzymology*; D038081:Organogenesis / Q000187:drug effects / Q000235:genetics; D010766:Phosphorylation / Q000187:drug effects; D011725:Pyridines / Q000494:pharmacology; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D015415:Biomarkers; D003470:Culture Media; D007093:Imidazoles; D011725:Pyridines; D048049:Extracellular Signal-Regulated MAP Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; C093642:SB 203580