title: Discovery of novel glucose-regulated proteins in isolated human pancreatic islets using LC-MS/MS-based proteomics.
abstract: The prevalence of diabetes mellitus is increasing dramatically throughout the world, and the disease has become a major public health issue. The most common form of the disease, type 2 diabetes, is characterized by insulin resistance and insufficient insulin production from the pancreatic beta-cell. Since glucose is the most potent regulator of beta-cell function under physiological conditions, identification of the insulin secretory defect underlying type 2 diabetes requires a better understanding of glucose regulation of human beta-cell function. To this aim, a bottom-up LC-MS/MS-based proteomics approach was used to profile pooled islets from multiple donors under basal (5 mM) or high (15 mM) glucose conditions. Our analysis discovered 256 differentially abundant proteins (∼p < 0.05) after 24 h of high glucose exposure from more than 4500 identified in total. Several novel glucose-regulated proteins were elevated under high glucose conditions, including regulators of mRNA splicing (pleiotropic regulator 1), processing (retinoblastoma binding protein 6), and function (nuclear RNA export factor 1), in addition to neuron navigator 1 and plasminogen activator inhibitor 1. Proteins whose abundances markedly decreased during incubation at 15 mM glucose included Bax inhibitor 1 and synaptotagmin-17. Up-regulation of dicer 1 and SLC27A2 and down-regulation of phospholipase Cβ4 were confirmed by Western blots. Many proteins found to be differentially abundant after high glucose stimulation are annotated as uncharacterized or hypothetical. These findings expand our knowledge of glucose regulation of the human islet proteome and suggest many hitherto unknown responses to glucose that require additional studies to explore novel functional roles.
authors.affiliation: Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, USA.
authors.forename: Alexandra C
authors.initials: AC
authors.lastname: Schrimpe-Rutledge
authors.forename: Ghislaine
authors.initials: G
authors.lastname: Fontès
authors.forename: Marina A
authors.initials: MA
authors.lastname: Gritsenko
authors.forename: Angela D
authors.initials: AD
authors.lastname: Norbeck
authors.forename: David J
authors.initials: DJ
authors.lastname: Anderson
authors.forename: Katrina M
authors.initials: KM
authors.lastname: Waters
authors.forename: Joshua N
authors.initials: JN
authors.lastname: Adkins
authors.forename: Richard D
authors.initials: RD
authors.lastname: Smith
authors.forename: Vincent
authors.initials: V
authors.lastname: Poitout
authors.forename: Thomas O
authors.initials: TO
authors.lastname: Metz
mesh_terms: D000123:Acetyltransferases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D002852:Chromatography, Ion Exchange; D056148:Chromatography, Reverse-Phase; D016000:Cluster Analysis; D003066:Coenzyme A Ligases / Q000378:metabolism; D053487:DEAD-box RNA Helicases / Q000378:metabolism; D000081031:Fatty Acid Elongases; D005786:Gene Expression Regulation; D005947:Glucose / Q000502:physiology*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D007515:Islets of Langerhans / Q000378:metabolism*; D008928:Mitochondria / Q000201:enzymology; D010449:Peptide Mapping; D054799:Phospholipase C beta / Q000378:metabolism; D020543:Proteome / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D040901:Proteomics; D043244:Ribonuclease III / Q000378:metabolism; D053719:Tandem Mass Spectrometry; D046509:Tissue Culture Techniques; D000098859:Long-Chain-Fatty-Acid-CoA Ligase
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D020543:Proteome; D000123:Acetyltransferases; D000081031:Fatty Acid Elongases; C408087:DICER1 protein, human; D043244:Ribonuclease III; C518042:PLCB4 protein, human; D054799:Phospholipase C beta; D053487:DEAD-box RNA Helicases; D003066:Coenzyme A Ligases; D000098859:Long-Chain-Fatty-Acid-CoA Ligase; D005947:Glucose