Huntingtin-interacting protein 14 is a type 1 diabetes candidate protein regulating insulin secretion and beta-cell apoptosis

Proc Natl Acad Sci U S A. 2011 Sep 13;108(37):E681-8. doi: 10.1073/pnas.1104384108. Epub 2011 Jun 24.

Abstract

Type 1 diabetes (T1D) is a complex disease characterized by the loss of insulin-secreting β-cells. Although the disease has a strong genetic component, and several loci are known to increase T1D susceptibility risk, only few causal genes have currently been identified. To identify disease-causing genes in T1D, we performed an in silico "phenome-interactome analysis" on a genome-wide linkage scan dataset. This method prioritizes candidates according to their physical interactions at the protein level with other proteins involved in diabetes. A total of 11 genes were predicted to be likely disease genes in T1D, including the INS gene. An unexpected top-scoring candidate gene was huntingtin-interacting protein (HIP)-14/ZDHHC17. Immunohistochemical analysis of pancreatic sections demonstrated that HIP14 is almost exclusively expressed in insulin-positive cells in islets of Langerhans. RNAi knockdown experiments established that HIP14 is an antiapoptotic protein required for β-cell survival and glucose-stimulated insulin secretion. Proinflammatory cytokines (IL-1β and IFN-γ) that mediate β-cell dysfunction in T1D down-regulated HIP14 expression in insulin-secreting INS-1 cells and in isolated rat and human islets. Overexpression of HIP14 was associated with a decrease in IL-1β-induced NF-κB activity and protection against IL-1β-mediated apoptosis. Our study demonstrates that the current network biology approach is a valid method to identify genes of importance for T1D and may therefore embody the basis for more rational and targeted therapeutic approaches.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Animals
  • Apoptosis* / drug effects
  • Binding Sites
  • Cell Survival / drug effects
  • Child
  • Cytokines / metabolism
  • Diabetes Mellitus, Type 1 / genetics
  • Diabetes Mellitus, Type 1 / metabolism*
  • Diabetes Mellitus, Type 1 / pathology*
  • Female
  • Genetic Predisposition to Disease
  • Glucose / pharmacology
  • Humans
  • Insulin / metabolism*
  • Insulin Secretion
  • Insulin-Secreting Cells / drug effects
  • Insulin-Secreting Cells / metabolism*
  • Insulin-Secreting Cells / pathology*
  • Interleukin-1beta / pharmacology
  • Male
  • Mice
  • Middle Aged
  • NF-kappa B / metabolism
  • Nerve Tissue Proteins / metabolism*
  • Polymorphism, Single Nucleotide / genetics
  • Protein Binding / drug effects
  • Rats
  • Transcription Factors / metabolism
  • Young Adult

Substances

  • Cytokines
  • Insulin
  • Interleukin-1beta
  • NF-kappa B
  • Nerve Tissue Proteins
  • Transcription Factors
  • Glucose