Genetic, Inflammatory, and Epithelial Cell Differentiation Factors Control Expression of Human Calpain-14

G3 (Bethesda). 2019 Mar 7;9(3):729-736. doi: 10.1534/g3.118.200901.

Abstract

Eosinophilic esophagitis (EoE) is a chronic, food-driven allergic disease resulting in eosinophilic esophageal inflammation. We recently found that EoE susceptibility is associated with genetic variants in the promoter of CAPN14, a gene with reported esophagus-specific expression. CAPN14 is dynamically up-regulated as a function of EoE disease activity and after exposure of epithelial cells to interleukin-13 (IL-13). Herein, we aimed to explore molecular modulation of CAPN14 expression. We identified three putative binding sites for the IL-13-activated transcription factor STAT6 in the promoter and first intron of CAPN14 Luciferase reporter assays revealed that the two most distal STAT6 elements were required for the ∼10-fold increase in promoter activity subsequent to stimulation with IL-13 or IL-4, and also for the genotype-dependent reduction in IL-13-induced promoter activity. One of the STAT6 elements in the promoter was necessary for IL-13-mediated induction of CAPN14 promoter activity while the other STAT6 promoter element was necessary for full induction. Chromatin immunoprecipitation in IL-13 stimulated esophageal epithelial cells was used to further support STAT6 binding to the promoter of CAPN14 at these STAT6 binding sites. The highest CAPN14 and calpain-14 expression occurred with IL-13 or IL-4 stimulation of esophageal epithelial cells under culture conditions that allow the cells to differentiate into a stratified epithelium. This work corroborates a candidate molecular mechanism for EoE disease etiology in which the risk variant at 2p23 dampens CAPN14 expression in differentiated esophageal epithelial cells following IL-13/STAT6 induction of CAPN14 promoter activity.

Keywords: CAPN14; Eosinophilic Esophagitis; Genetics of Immunity; IL-13; IL-4; STAT6.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calpain / genetics*
  • Cell Line
  • Eosinophilic Esophagitis / genetics*
  • Eosinophilic Esophagitis / metabolism
  • Epithelial Cells / enzymology*
  • Gene Expression Regulation*
  • Genetic Predisposition to Disease
  • Humans
  • Inflammation
  • Interleukin-13 / metabolism*
  • Interleukin-4 / metabolism
  • Polymorphism, Single Nucleotide*
  • Promoter Regions, Genetic
  • STAT6 Transcription Factor / metabolism*

Substances

  • IL4 protein, human
  • Interleukin-13
  • STAT6 Transcription Factor
  • STAT6 protein, human
  • Interleukin-4
  • Calpain
  • calpain 14, human

Associated data

  • figshare/10.25387/g3.7565792