Research Resource: A Dual Proteomic Approach Identifies Regulated Islet Proteins During β-Cell Mass Expansion In Vivo

TY - JOUR

T1 - Research Resource: A Dual Proteomic Approach Identifies Regulated Islet Proteins During β-Cell Mass Expansion In Vivo

AU - Horn, Signe

AU - Kirkegaard, Jeannette S.

AU - Hoelper, Soraya

AU - Seymour, Philip A.

AU - Rescan, Claude

AU - Nielsen, Jens H.

AU - Madsen, Ole D.

AU - Jensen, Jan N

AU - Kruger, Marcus

AU - Gronborg, Mads

AU - Ahnfelt-Rønne, Jonas

N1 - M1 - Copyright (C) 2017 U.S. National Library of Medicine. MEDLINE AN 2016488258(Journal; Article; (JOURNAL ARTICLE))

PY - 2016/1

Y1 - 2016/1

N2 - Diabetes is characterized by insulin insufficiency due to a relative paucity of functional β-cell mass. Thus, strategies for increasing β-cell mass in situ are sought-after for therapeutic purposes. Pregnancy is a physiological state capable of inducing robust β-cell mass expansion, however, the mechanisms driving this expansion are not fully understood. Thus, the aim of this study was to characterize pregnancy-induced changes in the islet proteome at the peak of β-cell proliferation in mice. Islets from pregnant and nonpregnant littermates were compared via 2 proteomic strategies. In vivo pulsed stable isotope labeling of amino acids in cell culture was used to monitor de novo protein synthesis during the first 14.5 days of pregnancy. In parallel, protein abundance was determined using ex vivo dimethyl labelling at gestational day 14.5. Comparison of the 2 datasets revealed 170 islet proteins to be up regulated as a response to pregnancy. These included several proteins, not previously associated with pregnancy-induced islet expansion, such as CLIC1, STMN1, MCM6, PPIB, NEDD4, and HLTF. Confirming the validity of our approach, we also identified proteins encoded by genes known to be associated with pregnancy-induced islet expansion, such as CHGB, IGFBP5, MATN2, EHHADH, IVD, and BMP1. Bioinformatic analyses demonstrated enrichment and activation of the biological functions: “protein synthesis” and “proliferation,” and predicted the transcription factors HNF4, MYC, MYCN, E2F1, NFE2L2, and HNF1 as upstream regulators of the observed expressional changes. As the first characterization of the isletproteome during pregnancy, this study provides novel insight into the mechanisms involved in promoting pregnancy-induced β-cell mass expansion and function.

AB - Diabetes is characterized by insulin insufficiency due to a relative paucity of functional β-cell mass. Thus, strategies for increasing β-cell mass in situ are sought-after for therapeutic purposes. Pregnancy is a physiological state capable of inducing robust β-cell mass expansion, however, the mechanisms driving this expansion are not fully understood. Thus, the aim of this study was to characterize pregnancy-induced changes in the islet proteome at the peak of β-cell proliferation in mice. Islets from pregnant and nonpregnant littermates were compared via 2 proteomic strategies. In vivo pulsed stable isotope labeling of amino acids in cell culture was used to monitor de novo protein synthesis during the first 14.5 days of pregnancy. In parallel, protein abundance was determined using ex vivo dimethyl labelling at gestational day 14.5. Comparison of the 2 datasets revealed 170 islet proteins to be up regulated as a response to pregnancy. These included several proteins, not previously associated with pregnancy-induced islet expansion, such as CLIC1, STMN1, MCM6, PPIB, NEDD4, and HLTF. Confirming the validity of our approach, we also identified proteins encoded by genes known to be associated with pregnancy-induced islet expansion, such as CHGB, IGFBP5, MATN2, EHHADH, IVD, and BMP1. Bioinformatic analyses demonstrated enrichment and activation of the biological functions: “protein synthesis” and “proliferation,” and predicted the transcription factors HNF4, MYC, MYCN, E2F1, NFE2L2, and HNF1 as upstream regulators of the observed expressional changes. As the first characterization of the isletproteome during pregnancy, this study provides novel insight into the mechanisms involved in promoting pregnancy-induced β-cell mass expansion and function.

U2 - 10.1210/me.2015-1208

DO - 10.1210/me.2015-1208

M3 - Journal article

C2 - 26649805

SN - 1944-9917

VL - 30

SP - 133

EP - 143

JO - Molecular endocrinology (Baltimore, Md.)

JF - Molecular endocrinology (Baltimore, Md.)

IS - 1

ER -