title: Thrombin stimulates insulin secretion via protease-activated receptor-3.
abstract: The disease mechanisms underlying type 2 diabetes (T2D) remain poorly defined. Here we aimed to explore the pathophysiology of T2D by analyzing gene co-expression networks in human islets. Using partial correlation networks we identified a group of co-expressed genes ('module') including F2RL2 that was associated with glycated hemoglobin. F2Rl2 is a G-protein-coupled receptor (GPCR) that encodes protease-activated receptor-3 (PAR3). PAR3 is cleaved by thrombin, which exposes a 6-amino acid sequence that acts as a 'tethered ligand' to regulate cellular signaling. We have characterized the effect of PAR3 activation on insulin secretion by static insulin secretion measurements, capacitance measurements, studies of diabetic animal models and patient samples. We demonstrate that thrombin stimulates insulin secretion, an effect that was prevented by an antibody that blocks the thrombin cleavage site of PAR3. Treatment with a peptide corresponding to the PAR3 tethered ligand stimulated islet insulin secretion and single β-cell exocytosis by a mechanism that involves activation of phospholipase C and Ca(2+) release from intracellular stores. Moreover, we observed that the expression of tissue factor, which regulates thrombin generation, was increased in human islets from T2D donors and associated with enhanced β-cell exocytosis. Finally, we demonstrate that thrombin generation potential in patients with T2D was associated with increased fasting insulin and insulinogenic index. The findings provide a previously unrecognized link between hypercoagulability and hyperinsulinemia and suggest that reducing thrombin activity or blocking PAR3 cleavage could potentially counteract the exaggerated insulin secretion that drives insulin resistance and β-cell exhaustion in T2D.
authors.affiliation: a Research Program on Biomedical Informatics (GRIB); Hospital del Mar Medical Research Institute (IMIM) ; Barcelona , Catalonia , Spain.|b Universitat Pompeu Fabra; Parc de Recerca Biomédica de Barcelona ; Barcelona , Catalonia , Spain.|c Lund University Diabetes Center; Lund University ; Malmö , Sweden.|d Interdisciplinary Center for Clinical Research (IZKF); RWTH University Medical School ; Aachen , Germany.|i These authors contributed equally to this work.
authors.forename: Sonja
authors.initials: S
authors.lastname: Hänzelmann
authors.affiliation: c Lund University Diabetes Center; Lund University ; Malmö , Sweden.|i These authors contributed equally to this work.
authors.forename: Jinling
authors.initials: J
authors.lastname: Wang
authors.affiliation: b Universitat Pompeu Fabra; Parc de Recerca Biomédica de Barcelona ; Barcelona , Catalonia , Spain.|e Center for Complex Network Research; Northeastern University ; Boston , MA USA.
authors.forename: Emre
authors.initials: E
authors.lastname: Güney
authors.affiliation: c Lund University Diabetes Center; Lund University ; Malmö , Sweden.
authors.forename: Yunzhao
authors.initials: Y
authors.lastname: Tang
authors.affiliation: c Lund University Diabetes Center; Lund University ; Malmö , Sweden.
authors.forename: Enming
authors.initials: E
authors.lastname: Zhang
authors.affiliation: c Lund University Diabetes Center; Lund University ; Malmö , Sweden.
authors.forename: Annika S
authors.initials: AS
authors.lastname: Axelsson
authors.affiliation: c Lund University Diabetes Center; Lund University ; Malmö , Sweden.
authors.forename: Hannah
authors.initials: H
authors.lastname: Nenonen
authors.affiliation: c Lund University Diabetes Center; Lund University ; Malmö , Sweden.
authors.forename: Albert S
authors.initials: AS
authors.lastname: Salehi
authors.affiliation: c Lund University Diabetes Center; Lund University ; Malmö , Sweden.|f Department of Cell Physiology and Metabolism ; University Medical Center ; Geneva , Switzerland.
authors.forename: Claes B
authors.initials: CB
authors.lastname: Wollheim
authors.affiliation: g Clinical Coagulation Research Unit ; Department of Clinical Sciences Malmö; Lund University ; Malmö , Sweden.
authors.forename: Eva
authors.initials: E
authors.lastname: Zetterberg
authors.affiliation: g Clinical Coagulation Research Unit ; Department of Clinical Sciences Malmö; Lund University ; Malmö , Sweden.
authors.forename: Erik
authors.initials: E
authors.lastname: Berntorp
authors.affiliation: d Interdisciplinary Center for Clinical Research (IZKF); RWTH University Medical School ; Aachen , Germany.|h Helmholtz-Institute for Biomedical Engineering; RWTH University Medical School ; Aachen , Germany.
authors.forename: Ivan G
authors.initials: IG
authors.lastname: Costa
authors.affiliation: a Research Program on Biomedical Informatics (GRIB); Hospital del Mar Medical Research Institute (IMIM) ; Barcelona , Catalonia , Spain.|b Universitat Pompeu Fabra; Parc de Recerca Biomédica de Barcelona ; Barcelona , Catalonia , Spain.
authors.forename: Robert
authors.initials: R
authors.lastname: Castelo
authors.affiliation: c Lund University Diabetes Center; Lund University ; Malmö , Sweden.|i These authors contributed equally to this work.
authors.forename: Anders H
authors.initials: AH
authors.lastname: Rosengren
mesh_terms: D002478:Cells, Cultured; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D005089:Exocytosis / Q000187:drug effects / Q000235:genetics; D020869:Gene Expression Profiling; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000187:drug effects* / Q000378:metabolism* / Q000473:pathology; D046228:Microarray Analysis; D044463:Receptor, PAR-1 / Q000378:metabolism / Q000502:physiology*; D013917:Thrombin / Q000494:pharmacology*; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D007328:Insulin; C000610686:PAR (protease-activated receptor)-3 receptor, human; D044463:Receptor, PAR-1; D013917:Thrombin
keywords: insulin secretion in vitro; insulin secretion in vivo; islets; pathogenic mechanisms