title: Proteomic screening of glucose-responsive and glucose non-responsive MIN-6 beta cells reveals differential expression of proteins involved in protein folding, secretion and oxidative stress.
abstract: The glucose-sensitive insulin-secretion (GSIS) phenotype is relatively unstable in long-term culture of beta cells. The purpose of this study was to investigate relative changes in the proteome between glucose-responsive (low passage) and glucose non-responsive (high passage) murine MIN-6 pancreatic beta cells. The 2D-DIGE and subsequent DeCyder analysis detected 3351 protein spots in the pH range of 4-7. Comparing MIN-6(H) to MIN-6(L) and using a threshold of 1.2-fold, the number of proteins with a decrease in expression level was 152 (4.5%), similar was 3140 (93.7%) and increased 59 (1.8%). From the differentially expressed proteins identified in this study, groups of proteins associated with the endoplasmic reticulum (ER) and proteins involved in oxidative stress were found to be significantly decreased in the high-passage (H passage) cells. These proteins included endoplasmic reticulum protein 29 (ERp29); 78-kDa glucose-related protein, (GRP78); 94-kDa glucose-related protein (GRP94); protein disulphide isomerase; carbonyl reductase 3; peroxidoxin 4 and superoxide dismutase 1. These results suggest that non-GSIS MIN-6 cells do not have the same ability/capacity of glucose-responsive MIN-6 cells to successfully fold, modify or secrete proteins and counteract the problems associated with oxidative stress.
authors.affiliation: National Institute for Cellular Biotechnology, Dublin City University, Dublin, Ireland. paul.dowling@dcu.ie
authors.forename: Paul
authors.initials: P
authors.lastname: Dowling
authors.forename: Lorraine
authors.initials: L
authors.lastname: O'Driscoll
authors.forename: Finbarr
authors.initials: F
authors.lastname: O'Sullivan
authors.forename: Andrew
authors.initials: A
authors.lastname: Dowd
authors.forename: Michael
authors.initials: M
authors.lastname: Henry
authors.forename: Per Bendix
authors.initials: PB
authors.lastname: Jeppesen
authors.forename: Paula
authors.initials: P
authors.lastname: Meleady
authors.forename: Martin
authors.initials: M
authors.lastname: Clynes
mesh_terms: D000818:Animals; D002460:Cell Line; D015180:Electrophoresis, Gel, Two-Dimensional; D000091342:Endoplasmic Reticulum Chaperone BiP; D005947:Glucose / Q000494:pharmacology*; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000187:drug effects* / Q000378:metabolism*; D051379:Mice; D018384:Oxidative Stress; D040081:Protein Array Analysis; D017510:Protein Folding; D020543:Proteome / Q000302:isolation & purification / Q000378:metabolism; D040901:Proteomics / Q000379:methods*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013347:Subcellular Fractions / Q000378:metabolism
chemical_list: D000091342:Endoplasmic Reticulum Chaperone BiP; C000717248:Hspa5 protein, mouse; D007328:Insulin; D020543:Proteome; D005947:Glucose