title: Glucose-induced changes of multiple mouse islet proteins analysed by two-dimensional gel electrophoresis and mass spectrometry.
abstract: OBJECTIVE
  The aim of this study was to investigate molecular mechanisms of glucose-induced changes in islets of Langerhans by analysing global changes in protein patterns of islets exposed to elevated glucose concentrations.
  
  
  METHODS
  Islets were isolated from C57BL/6J mice and used either directly or after exposure to 11 mmol/l glucose for 24 h. Islet protein profiles were obtained by two-dimensional gel electrophoresis, and protein spots were identified by peptide mass fingerprinting using mass spectrometry.
  
  
  RESULTS
  Two-dimensional gels of freshly isolated islets and islets exposed to 11 mmol/l glucose contained 1,074 and 1,254 spots, respectively. The number of differentially expressed spots was 379, with 20 spots appearing as new proteins in islets exposed to 11 mmol/l glucose. We identified 124 spots corresponding to 77 protein entries and generated a reference map from freshly isolated islets. Actin, alpha enolase, cytokeratin 8, endoplasmin, glucose-regulated proteins, heat shock proteins, peroxiredoxins, prohormone convertase 2, protein disulphide isomerase, superoxide dismutase, tubulin, and V-type H+ -ATPase (V1 subunit A) were upregulated in islets exposed to 11 mmol/l glucose. In contrast, exocrine proteins and secretagogin were downregulated in these islets compared with in freshly isolated islets.
  
  
  CONCLUSIONS
  The islet proteome approach revealed simultaneous changes in protein patterns of islets exposed to elevated glucose concentrations, indicating enhanced insulin synthesis, granular mobilisation and maturation, and increased stress response. The changes may be of relevance for the understanding of altered islet function in the hyperglycaemic state. It is expected that the islet reference map will become an important tool for dissecting multifactorial islet processes.
authors.affiliation: Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Ahmed
authors.forename: P
authors.initials: P
authors.lastname: Bergsten
mesh_terms: D000818:Animals; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods; D004798:Enzymes / Q000302:isolation & purification / Q000378:metabolism; D005947:Glucose / Q000494:pharmacology*; D007515:Islets of Langerhans / Q000187:drug effects; D008297:Male; D013058:Mass Spectrometry / Q000379:methods; D051379:Mice; D008810:Mice, Inbred C57BL; D011506:Proteins / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D004798:Enzymes; D011506:Proteins; D005947:Glucose
references.citation: Diabetologia. 1982 May;22(5):301-8
references.pmid: 6284576
references.citation: Nat Rev Mol Cell Biol. 2003 Mar;4(3):181-91
references.pmid: 12612637
references.citation: J Cell Sci. 2001 Jun;114(Pt 11):2145-54
references.pmid: 11493650
references.citation: Diabetes. 1999 Jan;48(1):99-105
references.pmid: 9892228
references.citation: Am J Physiol. 1995 Feb;268(2 Pt 1):E282-7
references.pmid: 7864105
references.citation: Diabetologia. 2002 Jun;45(6):867-76
references.pmid: 12107731
references.citation: Diabetologia. 1994 Jan;37(1):15-21
references.pmid: 7512059
references.citation: Acta Endocrinol Suppl (Copenh). 1976;205:283-94
references.pmid: 826064
references.citation: Diabetologia. 1997 May;40(5):487-95
references.pmid: 9165215
references.citation: J Endocrinol. 1993 Feb;136(2):289-96
references.pmid: 8459194
references.citation: Anal Chem. 1996 Mar 1;68(5):850-8
references.pmid: 8779443
references.citation: Nature. 1988 May 5;333(6168):93-6
references.pmid: 3283564
references.citation: Diabetes. 1992 Jul;41(7):792-806
references.pmid: 1612193
references.citation: Annu Rev Cell Dev Biol. 1999;15:141-83
references.pmid: 10611960
references.citation: Electrophoresis. 2000 Apr;21(6):1037-53
references.pmid: 10786879
references.citation: Virchows Arch A Pathol Anat Histopathol. 1987;412(1):53-61
references.pmid: 2446417
references.citation: J Biol Chem. 1995 Apr 14;270(15):8971-5
references.pmid: 7721807
references.citation: Diabetologia. 2002 Nov;45(11):1550-61
references.pmid: 12436339
references.citation: Physiol Rev. 1999 Apr;79(2):425-49
references.pmid: 10221986
references.citation: Am J Physiol. 1999 Feb;276(2 Pt 1):C507-10
references.pmid: 9950779
references.citation: Nutr Rev. 2001 Jun;59(6):177-9
references.pmid: 11444594
references.citation: Mol Cell Proteomics. 2002 Jul;1(7):509-16
references.pmid: 12239279
references.citation: J Proteome Res. 2003 Mar-Apr;2(2):199-205
references.pmid: 12716134
references.citation: Nature. 1980 Jan 3;283(5742):100-2
references.pmid: 6985712
references.citation: Ann Endocrinol (Paris). 2004 Feb;65(1):29-36
references.pmid: 15122089
references.citation: Transplantation. 1997 May 27;63(10):1537-40
references.pmid: 9175827
references.citation: Diabetes. 2004 Feb;53 Suppl 1:S136-42
references.pmid: 14749279
references.citation: Diabetes. 1999 Dec;48(12):2398-406
references.pmid: 10580429
references.citation: Anal Chem. 2000 Jan 1;72(1):48A-55A
references.pmid: 10655623
references.citation: Biochem Soc Trans. 2002 Apr;30(2):328-32
references.pmid: 12023874
references.citation: Proteomics. 2001 Jan;1(1):136-63
references.pmid: 11680894