A possible mechanism behind autoimmune disorders discovered by genome-wide linkage and association analysis in celiac disease

PLoS One. 2013 Aug 2;8(8):e70174. doi: 10.1371/journal.pone.0070174. Print 2013.

Abstract

Celiac disease is a common autoimmune disorder characterized by an intestinal inflammation triggered by gluten, a storage protein found in wheat, rye and barley. Similar to other autoimmune diseases such as type 1 diabetes, psoriasis and rheumatoid arthritis, celiac disease is the result of an immune response to self-antigens leading to tissue destruction and production of autoantibodies. Common diseases like celiac disease have a complex pattern of inheritance with inputs from both environmental as well as additive and non-additive genetic factors. In the past few years, Genome Wide Association Studies (GWAS) have been successful in finding genetic risk variants behind many common diseases and traits. To complement and add to the previous findings, we performed a GWAS including 206 trios from 97 nuclear Swedish and Norwegian families affected with celiac disease. By stratifying for HLA-DQ, we identified a new genome-wide significant risk locus covering the DUSP10 gene. To further investigate the associations from the GWAS we performed pathway analyses and two-locus interaction analyses. These analyses showed an over-representation of genes involved in type 2 diabetes and identified a set of candidate mechanisms and genes of which some were selected for mRNA expression analysis using small intestinal biopsies from 98 patients. Several genes were expressed differently in the small intestinal mucosa from patients with celiac autoimmunity compared to intestinal mucosa from control patients. From top-scoring regions we identified susceptibility genes in several categories: 1) polarity and epithelial cell functionality; 2) intestinal smooth muscle; 3) growth and energy homeostasis, including proline and glutamine metabolism; and finally 4) innate and adaptive immune system. These genes and pathways, including specific functions of DUSP10, together reveal a new potential biological mechanism that could influence the genesis of celiac disease, and possibly also other chronic disorders with an inflammatory component.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Autoimmune Diseases / genetics*
  • Autoimmune Diseases / immunology
  • Autoimmune Diseases / pathology
  • Autoimmunity / genetics*
  • Autoimmunity / immunology
  • Case-Control Studies
  • Celiac Disease / genetics*
  • Celiac Disease / immunology
  • Celiac Disease / pathology
  • Child
  • Dual-Specificity Phosphatases / genetics*
  • Dual-Specificity Phosphatases / immunology
  • Female
  • Genetic Linkage
  • Genome, Human*
  • Genome-Wide Association Study
  • HLA-DQ Antigens / genetics
  • HLA-DQ Antigens / immunology
  • Humans
  • Immune System / immunology*
  • Immune System / pathology
  • Intestines / immunology
  • Intestines / pathology
  • Male
  • Mitogen-Activated Protein Kinase Phosphatases / genetics*
  • Mitogen-Activated Protein Kinase Phosphatases / immunology
  • Nuclear Family
  • Polymorphism, Single Nucleotide / genetics*

Substances

  • HLA-DQ Antigens
  • DUSP10 protein, human
  • Mitogen-Activated Protein Kinase Phosphatases
  • Dual-Specificity Phosphatases

Grants and funding

The principal funding for this study was provided through the regional agreement on medical training and clinical research (ALF) between Gothenburg County Council and Gothenburg University. We also thank Bengt Ihre’s, Claes Groschinsky’s, Magnus Bergvall’s, Nilsson-Ehle’s, Tore Nilson’s and Professor Nanna Svartz Foundations, Kungliga fysiografiska sällskapet in Lund, Frimurare barnhusdirektionen, Ruth and Richard Julin Foundation and the Swedish Society of Medicine. The Swedish Medical Research Council and the Celiac Disease Foundation supported family sample collections. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.