title: Glycolytic network restructuring integral to the energetics of embryonic stem cell cardiac differentiation.
abstract: Decoding of the bioenergetic signature underlying embryonic stem cell cardiac differentiation has revealed a mandatory transformation of the metabolic infrastructure with prominent mitochondrial network expansion and a distinctive switch from glycolysis to oxidative phosphorylation. Here, we demonstrate that despite reduction in total glycolytic capacity, stem cell cardiogenesis engages a significant transcriptome, proteome, as well as enzymatic and topological rearrangement in the proximal, medial, and distal modules of the glycolytic pathway. Glycolytic restructuring was manifested by a shift in hexokinase (Hk) isoforms from Hk-2 to cardiac Hk-1, with intracellular and intermyofibrillar localization mapping mitochondrial network arrangement. Moreover, upregulation of cardiac-specific enolase 3, phosphofructokinase, and phosphoglucomutase and a marked increase in glyceraldehyde 3-phosphate dehydrogenase (GAPDH) phosphotransfer activity, along with apparent post-translational modifications of GAPDH and phosphoglycerate kinase, were all distinctive for derived cardiomyocytes compared to the embryonic stem cell source. Lactate dehydrogenase (LDH) isoforms evolved towards LDH-2 and LDH-3, containing higher proportions of heart-specific subunits, and pyruvate dehydrogenase isoforms rearranged between E1alpha and E1beta, transitions favorable for substrate oxidation in mitochondria. Concomitantly, transcript levels of fetal pyruvate kinase isoform M2, aldolase 3, and transketolase, which shunt the glycolytic with pentose phosphate pathways, were reduced. Collectively, changes in glycolytic pathway modules indicate active redeployment, which would facilitate connectivity of the expanding mitochondrial network with ATP utilization sites. Thus, the delineated developmental dynamics of the glycolytic phosphotransfer network is integral to the remodeling of cellular energetic infrastructure underlying stem cell cardiogenesis.
authors.affiliation: Marriott Heart Disease Research Program, Division of Cardiovascular Diseases, Departments of Medicine, Molecular Pharmacology and Experimental Therapeutics, and Medical Genetics, Mayo Clinic College of Medicine, Mayo Clinic, 200 First Street SW, Stabile 5, Rochester, MN 55905, USA.
authors.forename: Susan
authors.initials: S
authors.lastname: Chung
authors.forename: D Kent
authors.initials: DK
authors.lastname: Arrell
authors.forename: Randolph S
authors.initials: RS
authors.lastname: Faustino
authors.forename: Andre
authors.initials: A
authors.lastname: Terzic
authors.forename: Petras P
authors.initials: PP
authors.lastname: Dzeja
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D015180:Electrophoresis, Gel, Two-Dimensional; D053595:Embryonic Stem Cells / Q000166:cytology*; D020869:Gene Expression Profiling; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000378:metabolism; D006019:Glycolysis; D007091:Image Processing, Computer-Assisted; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D055432:Metabolomics; D051379:Mice; D010427:Pentose Phosphate Pathway; D010735:Phosphoglycerate Kinase / Q000378:metabolism; D020033:Protein Isoforms; D011499:Protein Processing, Post-Translational
chemical_list: D020033:Protein Isoforms; D007770:L-Lactate Dehydrogenase; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D010735:Phosphoglycerate Kinase