Antibody-validated proteins in inflamed islets of fulminant type 1 diabetes profiled by laser-capture microdissection followed by mass spectrometry

PLoS One. 2014 Oct 16;9(10):e107664. doi: 10.1371/journal.pone.0107664. eCollection 2014.

Abstract

Background: There are no reports of proteomic analyses of inflamed islets in type 1 diabetes.

Procedures: Proteins expressed in the islets of enterovirus-associated fulminant type 1 diabetes (FT1DM) with extensive insulitis were identified by laser-capture microdissection mass spectrometry using formalin-fixed paraffin-embedded pancreatic tissues.

Results: Thirty-eight proteins were identified solely in FT1DM islets, most of which have not been previously linked to type 1 diabetes. Five protein-protein interacting clusters were identified, and the cellular localization of selected proteins was validated immunohistochemically. Migratory activity-related proteins, including plastin-2 (LCP1), moesin (MSN), lamin-B1 (LMNB1), Ras GTPase-activating-like protein (IQGAP1) and others, were identified in CD8+ T cells and CD68+ macrophages infiltrated to inflamed FT1DM islets. Proteins involved in successive signaling in innate/adaptive immunity were identified, including SAM domain and HD domain-containing protein 1 (SAMHD1), Ras GTPase-activating-like protein (IQGAP1), proteasome activator complex subunit 1 (PSME1), HLA class I histocompatibility antigen (HLA-C), and signal transducer and activator of transcription 1-alpha/beta (STAT1). Angiogenic (thymidine phosphorylase (TYMP)) and anti-angiogenic (tryptophan-tRNA ligase (WARS)) factors were identified in migrating CD8+ T cells and CD68+ macrophages. Proteins related to virus replication and cell proliferation, including probable ATP-dependent RNA helicase DEAD box helicase 5 (DDX5) and heterogeneous nuclear ribonucleoprotein H (HNRNPH1), were identified. The anti-apoptotic protein T-complex protein 1 subunit epsilon (CCT5), the anti-oxidative enzyme 6-phosphogluconate dehydrogenase (PDG), and the anti-viral and anti-apoptotic proteins serpin B6 (SERPINB6) and heat shock 70 kDa protein1-like (HSPA1L), were identified in FT1DM-affected islet cells.

Conclusion: The identified FT1DM-characterizing proteins include those involved in aggressive beta cell destruction through massive immune cell migration and proteins involved in angiogenesis and islet vasculature bleeding, cell repair, and anti-inflammatory processes. Several target proteins for future type 1 diabetes interventions were identified.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Antibodies / immunology*
  • Diabetes Mellitus, Type 1 / metabolism*
  • Diabetes Mellitus, Type 1 / pathology
  • Humans
  • Inflammation / metabolism
  • Inflammation / pathology
  • Islets of Langerhans / metabolism*
  • Islets of Langerhans / pathology
  • Laser Capture Microdissection*
  • Male
  • Mass Spectrometry*
  • Paraffin Embedding
  • Protein Interaction Maps
  • Proteomics*
  • Tissue Fixation

Substances

  • Antibodies

Grants and funding

This work was supported by a grant from the University of Yamanashi to professor Tetsuro Kobayashi and by Grant-in-Aid from the Ministry of Education, Culture, Science and Technology of Japan for Scientific Research (C) (245991321) (KA), and (24591319) (TK). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.