Abnormalities in proinsulin processing in islets from individuals with longstanding T1D

Emily K. Sims, Farooq Syed, Julius Nyalwidhe, Henry T. Bahnson, Leena Haataja, Cate Speake, Margaret A. Morris, Appakalai N. Balamurugan, Raghu Mirmira, Jerry Nadler, Teresa L. Mastracci, Peter Arvan, Carla J. Greenbaum, Carmella Evans-Molina

Research output: Contribution to journalArticle

Abstract

We recently described the persistence of detectable serum proinsulin in a large majority of individuals with longstanding type 1 diabetes (T1D), including individuals with undetectable serum C-peptide. Here, we sought to further explore the mechanistic etiologies of persistent proinsulin secretion in T1D at the level of the islet, using tissues obtained from human donors. Immunostaining for proinsulin and insulin was performed on human pancreatic sections from the Network for Pancreatic Organ Donors with Diabetes (nPOD) collection (n = 24). Differential proinsulin processing enzyme expression was analyzed using mass spectrometry analysis of human islets isolated from pancreatic sections with laser capture microdissection (n = 6). Proinsulin processing enzyme mRNA levels were assessed using quantitative real-time PCR in isolated human islets (n = 10) treated with or without inflammatory cytokines. Compared to nondiabetic controls, immunostaining among a subset (4/9) of insulin positive T1D donor islets revealed increased numbers of cells with proinsulin-enriched, insulin-poor staining. T1D donor islets also exhibited increased proinsulin fluorescence intensity relative to insulin fluorescence intensity. Laser capture microdissection followed by mass spectrometry revealed reductions in the proinsulin processing enzymes prohormone convertase 1/3 (PC1/3) and carboxypeptidase E (CPE) in T1D donors. Twenty-four hour treatment of human islets with inflammatory cytokines reduced mRNA expression of the processing enzymes PC1/3, PC2, and CPE. Taken together, these data provide new mechanistic insight into altered proinsulin processing in long-duration T1D and suggest that reduced β cell prohormone processing is associated with proinflammatory cytokine-induced reductions in proinsulin processing enzyme expression.

Original languageEnglish (US)
JournalTranslational Research
DOIs
StateAccepted/In press - Jan 1 2019

Fingerprint

Proinsulin
Medical problems
Type 1 Diabetes Mellitus
Proprotein Convertase 1
Processing
Tissue Donors
Microdissection
Carboxypeptidase H
Insulin
Laser Capture Microdissection
Enzymes
Cytokines
Mass spectrometry
Mass Spectrometry
Fluorescence
Messenger RNA
Lasers
C-Peptide
Serum
Islets of Langerhans

Keywords

  • CPE = carboxypeptidase E
  • ER = endoplasmic reticulum
  • IR = infrared
  • LCM = laser capture microdissection
  • LFQ = label-free quantification
  • nPOD = network for pancreatic organ donors with type 1 diabetes
  • PC1/3 = prohormone convertase 1/3
  • PC2 = prohormone convertase 2
  • T1D = type 1 diabetes
  • UV = ultraviolet

ASJC Scopus subject areas

  • Public Health, Environmental and Occupational Health
  • Biochemistry, medical
  • Physiology (medical)

Cite this

Abnormalities in proinsulin processing in islets from individuals with longstanding T1D. / Sims, Emily K.; Syed, Farooq; Nyalwidhe, Julius; Bahnson, Henry T.; Haataja, Leena; Speake, Cate; Morris, Margaret A.; Balamurugan, Appakalai N.; Mirmira, Raghu; Nadler, Jerry; Mastracci, Teresa L.; Arvan, Peter; Greenbaum, Carla J.; Evans-Molina, Carmella.

In: Translational Research, 01.01.2019.

Research output: Contribution to journalArticle

Sims, EK, Syed, F, Nyalwidhe, J, Bahnson, HT, Haataja, L, Speake, C, Morris, MA, Balamurugan, AN, Mirmira, R, Nadler, J, Mastracci, TL, Arvan, P, Greenbaum, CJ & Evans-Molina, C 2019, 'Abnormalities in proinsulin processing in islets from individuals with longstanding T1D', Translational Research. https://doi.org/10.1016/j.trsl.2019.08.001
Sims, Emily K. ; Syed, Farooq ; Nyalwidhe, Julius ; Bahnson, Henry T. ; Haataja, Leena ; Speake, Cate ; Morris, Margaret A. ; Balamurugan, Appakalai N. ; Mirmira, Raghu ; Nadler, Jerry ; Mastracci, Teresa L. ; Arvan, Peter ; Greenbaum, Carla J. ; Evans-Molina, Carmella. / Abnormalities in proinsulin processing in islets from individuals with longstanding T1D. In: Translational Research. 2019.
@article{f5a7ae7fab3941fdbe262f5c84cbdd57,
title = "Abnormalities in proinsulin processing in islets from individuals with longstanding T1D",
abstract = "We recently described the persistence of detectable serum proinsulin in a large majority of individuals with longstanding type 1 diabetes (T1D), including individuals with undetectable serum C-peptide. Here, we sought to further explore the mechanistic etiologies of persistent proinsulin secretion in T1D at the level of the islet, using tissues obtained from human donors. Immunostaining for proinsulin and insulin was performed on human pancreatic sections from the Network for Pancreatic Organ Donors with Diabetes (nPOD) collection (n = 24). Differential proinsulin processing enzyme expression was analyzed using mass spectrometry analysis of human islets isolated from pancreatic sections with laser capture microdissection (n = 6). Proinsulin processing enzyme mRNA levels were assessed using quantitative real-time PCR in isolated human islets (n = 10) treated with or without inflammatory cytokines. Compared to nondiabetic controls, immunostaining among a subset (4/9) of insulin positive T1D donor islets revealed increased numbers of cells with proinsulin-enriched, insulin-poor staining. T1D donor islets also exhibited increased proinsulin fluorescence intensity relative to insulin fluorescence intensity. Laser capture microdissection followed by mass spectrometry revealed reductions in the proinsulin processing enzymes prohormone convertase 1/3 (PC1/3) and carboxypeptidase E (CPE) in T1D donors. Twenty-four hour treatment of human islets with inflammatory cytokines reduced mRNA expression of the processing enzymes PC1/3, PC2, and CPE. Taken together, these data provide new mechanistic insight into altered proinsulin processing in long-duration T1D and suggest that reduced β cell prohormone processing is associated with proinflammatory cytokine-induced reductions in proinsulin processing enzyme expression.",
keywords = "CPE = carboxypeptidase E, ER = endoplasmic reticulum, IR = infrared, LCM = laser capture microdissection, LFQ = label-free quantification, nPOD = network for pancreatic organ donors with type 1 diabetes, PC1/3 = prohormone convertase 1/3, PC2 = prohormone convertase 2, T1D = type 1 diabetes, UV = ultraviolet",
author = "Sims, {Emily K.} and Farooq Syed and Julius Nyalwidhe and Bahnson, {Henry T.} and Leena Haataja and Cate Speake and Morris, {Margaret A.} and Balamurugan, {Appakalai N.} and Raghu Mirmira and Jerry Nadler and Mastracci, {Teresa L.} and Peter Arvan and Greenbaum, {Carla J.} and Carmella Evans-Molina",
year = "2019",
month = "1",
day = "1",
doi = "10.1016/j.trsl.2019.08.001",
language = "English (US)",
journal = "Translational Research",
issn = "1931-5244",
publisher = "Mosby Inc.",

}

TY - JOUR

T1 - Abnormalities in proinsulin processing in islets from individuals with longstanding T1D

AU - Sims, Emily K.

AU - Syed, Farooq

AU - Nyalwidhe, Julius

AU - Bahnson, Henry T.

AU - Haataja, Leena

AU - Speake, Cate

AU - Morris, Margaret A.

AU - Balamurugan, Appakalai N.

AU - Mirmira, Raghu

AU - Nadler, Jerry

AU - Mastracci, Teresa L.

AU - Arvan, Peter

AU - Greenbaum, Carla J.

AU - Evans-Molina, Carmella

PY - 2019/1/1

Y1 - 2019/1/1

N2 - We recently described the persistence of detectable serum proinsulin in a large majority of individuals with longstanding type 1 diabetes (T1D), including individuals with undetectable serum C-peptide. Here, we sought to further explore the mechanistic etiologies of persistent proinsulin secretion in T1D at the level of the islet, using tissues obtained from human donors. Immunostaining for proinsulin and insulin was performed on human pancreatic sections from the Network for Pancreatic Organ Donors with Diabetes (nPOD) collection (n = 24). Differential proinsulin processing enzyme expression was analyzed using mass spectrometry analysis of human islets isolated from pancreatic sections with laser capture microdissection (n = 6). Proinsulin processing enzyme mRNA levels were assessed using quantitative real-time PCR in isolated human islets (n = 10) treated with or without inflammatory cytokines. Compared to nondiabetic controls, immunostaining among a subset (4/9) of insulin positive T1D donor islets revealed increased numbers of cells with proinsulin-enriched, insulin-poor staining. T1D donor islets also exhibited increased proinsulin fluorescence intensity relative to insulin fluorescence intensity. Laser capture microdissection followed by mass spectrometry revealed reductions in the proinsulin processing enzymes prohormone convertase 1/3 (PC1/3) and carboxypeptidase E (CPE) in T1D donors. Twenty-four hour treatment of human islets with inflammatory cytokines reduced mRNA expression of the processing enzymes PC1/3, PC2, and CPE. Taken together, these data provide new mechanistic insight into altered proinsulin processing in long-duration T1D and suggest that reduced β cell prohormone processing is associated with proinflammatory cytokine-induced reductions in proinsulin processing enzyme expression.

AB - We recently described the persistence of detectable serum proinsulin in a large majority of individuals with longstanding type 1 diabetes (T1D), including individuals with undetectable serum C-peptide. Here, we sought to further explore the mechanistic etiologies of persistent proinsulin secretion in T1D at the level of the islet, using tissues obtained from human donors. Immunostaining for proinsulin and insulin was performed on human pancreatic sections from the Network for Pancreatic Organ Donors with Diabetes (nPOD) collection (n = 24). Differential proinsulin processing enzyme expression was analyzed using mass spectrometry analysis of human islets isolated from pancreatic sections with laser capture microdissection (n = 6). Proinsulin processing enzyme mRNA levels were assessed using quantitative real-time PCR in isolated human islets (n = 10) treated with or without inflammatory cytokines. Compared to nondiabetic controls, immunostaining among a subset (4/9) of insulin positive T1D donor islets revealed increased numbers of cells with proinsulin-enriched, insulin-poor staining. T1D donor islets also exhibited increased proinsulin fluorescence intensity relative to insulin fluorescence intensity. Laser capture microdissection followed by mass spectrometry revealed reductions in the proinsulin processing enzymes prohormone convertase 1/3 (PC1/3) and carboxypeptidase E (CPE) in T1D donors. Twenty-four hour treatment of human islets with inflammatory cytokines reduced mRNA expression of the processing enzymes PC1/3, PC2, and CPE. Taken together, these data provide new mechanistic insight into altered proinsulin processing in long-duration T1D and suggest that reduced β cell prohormone processing is associated with proinflammatory cytokine-induced reductions in proinsulin processing enzyme expression.

KW - CPE = carboxypeptidase E

KW - ER = endoplasmic reticulum

KW - IR = infrared

KW - LCM = laser capture microdissection

KW - LFQ = label-free quantification

KW - nPOD = network for pancreatic organ donors with type 1 diabetes

KW - PC1/3 = prohormone convertase 1/3

KW - PC2 = prohormone convertase 2

KW - T1D = type 1 diabetes

KW - UV = ultraviolet

UR - http://www.scopus.com/inward/record.url?scp=85071295999&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85071295999&partnerID=8YFLogxK

U2 - 10.1016/j.trsl.2019.08.001

DO - 10.1016/j.trsl.2019.08.001

M3 - Article

AN - SCOPUS:85071295999

JO - Translational Research

JF - Translational Research

SN - 1931-5244

ER -