title: Metabolomic analyses reveal profound differences in glycolytic and tricarboxylic acid cycle metabolism in glucose-responsive and -unresponsive clonal β-cell lines.
abstract: Insulin secretion from pancreatic β-cells is controlled by complex metabolic and energetic changes provoked by exposure to metabolic fuels. Perturbations in these processes lead to impaired insulin secretion, the ultimate cause of T2D (Type 2 diabetes). To increase our understanding of stimulus-secretion coupling and metabolic processes potentially involved in the pathogenesis of T2D, a comprehensive investigation of the metabolic response in the glucose-responsive INS-1 832/13 and glucose-unresponsive INS-1 832/2 β-cell lines was performed. For this metabolomics analysis, we used GC/MS (gas chromatography/mass spectrometry) combined with multivariate statistics. We found that perturbed secretion in the 832/2 line was characterized by disturbed coupling of glycolytic and TCA (tricarboxylic acid)-cycle metabolism. The importance of this metabolic coupling was reinforced by our observation that insulin secretion partially could be reinstated by stimulation of the cells with mitochondrial fuels which bypass glycolytic metabolism. Furthermore, metabolic and functional profiling of additional β-cell lines (INS-1, INS-1 832/1) confirmed the important role of coupled glycolytic and TCA-cycle metabolism in stimulus-secretion coupling. Dependence of the unresponsive clones on glycolytic metabolism was paralleled by increased stabilization of HIF-1α (hypoxia-inducible factor 1α). The relevance of a similar perturbation for human T2D was suggested by increased expression of HIF-1α target genes in islets from T2D patients.
authors.affiliation: Department of Clinical Sciences, Unit of Molecular Metabolism, Lund University Diabetes Centre, CRC, Scania University Hospital, 205 02 Malmö, Sweden. Peter.Spegel@med.lu.se
authors.forename: Peter
authors.initials: P
authors.lastname: Spégel
authors.forename: Siri
authors.initials: S
authors.lastname: Malmgren
authors.forename: Vladimir V
authors.initials: VV
authors.lastname: Sharoyko
authors.forename: Philip
authors.initials: P
authors.lastname: Newsholme
authors.forename: Thomas
authors.initials: T
authors.lastname: Koeck
authors.forename: Hindrik
authors.initials: H
authors.lastname: Mulder
mesh_terms: D000368:Aged; D000818:Animals; D001692:Biological Transport; D045744:Cell Line, Tumor; D002952:Citric Acid Cycle; D002999:Clone Cells; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism; D005260:Female; D005947:Glucose / Q000378:metabolism*; D006019:Glycolysis; D006801:Humans; D006943:Hyperglycemia; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics / Q000378:metabolism; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000378:metabolism*; D007515:Islets of Langerhans / Q000378:metabolism; D008297:Male; D055442:Metabolome; D008875:Middle Aged; D008928:Mitochondria / Q000378:metabolism; D010101:Oxygen Consumption; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D018085:Regulon
chemical_list: D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D007328:Insulin; D012333:RNA, Messenger; D005947:Glucose