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Protection of Epithelial Barrier Function Against Bacterial Infection by the IBD Candidate Gene PTPN2
Author(s) -
Krishnan Moorthy,
Alvarez Rocio,
Bennett Kaila,
Nair Meera,
Lo David,
McCole Declan
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.853.5
Subject(s) - barrier function , salmonella enterica , microbiology and biotechnology , biology , tight junction , citrobacter rodentium , intestinal permeability , intestinal epithelium , salmonella , citrobacter , western blot , immunology , gene , pathogen , enterobacteriaceae , epithelium , bacteria , escherichia coli , genetics
Intestinal pathogenic bacteria target various pathways to alter intestinal barrier function including modifying expression and distribution of tight junction proteins. Single nucleotide polymorphisms (SNPs) in protein tyrosine phosphatase non‐receptor type‐2 ( PTPN2) are associated with inflammatory bowel disease (IBD), while loss of PTPN2 compromises intestinal epithelial barrier function. Therefore, we sought to determine if PTPN2 deficiency increases barrier susceptibility to intestinal pathogens. 4kD FITC‐Dextran permeability was increased in wild type mice that received Citrobacter rodentium for 10 days when compared to uninfected mice. As expected, there was a greater increase in permeability in Ptpn2 heterogeneous (het) infected mice as compared to uninfected het and wild‐type infected mice. We generated a cellular model of PTPN2 loss using a lentiviral system to develop Caco2‐BBe (BBe) intestinal epithelial cells (IEC) that stably express short hairpin RNA for PTPN2 (KD). Cells were grown on semi‐permeable supports for 15 days and apically infected with Salmonella enterica typhimurium for 4 hrs. The trans‐epithelial electrical resistance (TER) was measured before and after Salmonella infection. Infected PTPN2 ‐deficient cells exhibited a greater reduction in TER value compared to infected control IEC. Western blot studies showed that phosphorylation of the Ptpn2 substrates, STAT‐1 and STAT‐3, as well as claudin‐2 expression, was increased in Salmonella ‐infected cells compared to uninfected cells. In conclusion, we report that loss of PTPN2 increased susceptibility to bacterial‐induced barrier dysregulation and was associated with elevated claudin‐2.