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Targeting Palmitoyl Acyltransferase ZDHHC21 Improves Epithelial Barrier Dysfunction Resulting from Burn Induced Systemic Inflammation
Author(s) -
Haines Ricci J,
Wang Chunyan,
Zhang Shimin,
Eitnier Rebecca A,
Wang Fang,
Yang Clement GY,
Wu Mack H
Publication year - 2017
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.31.1_supplement.1049.16
Subject(s) - barrier function , tight junction , inflammation , intestinal permeability , systemic inflammation , sepsis , intestinal mucosa , occludin , intestinal epithelium , immunology , medicine , chemistry , cancer research , epithelium , biology , microbiology and biotechnology , pathology
Clinical studies in burn patients demonstrate a close association between leaky guts and increased incidence or severity of sepsis and other complications. Severe thermal injury triggers intestinal inflammation contributing to intestinal epithelial hyperpermeability, which exacerbates systemic response leading to multiple organ failure and sepsis. In this study, we identified a significant function of a particular palmitoyl acyltransferase (PAT), ZDHHC21, in mediating signaling events required for gut hyperpermeability induced by inflammation. Using qPCR, we showed that ZDHHC21 mRNA production was enhanced two‐fold when intestinal epithelial cells were treated with TNFα/IFNγ in vitro. Additionally, using electric cell‐substrate impedance sensing (ECIS) assays and FITC‐dextran permeability assays, and pharmacologically targeting PATs with 2‐bromopalmitate (2BP) or specific targeting of ZDHHC21 with siRNA, showed significant epithelial barrier function improvement when treated with TNFα/IFNγ. Using the ABE assay and click chemistry, we showed that TNFα/IFNγ treatment of intestinal epithelial cells results in enhanced detection of total palmitoylated proteins, and this response is inhibited by 2BP. We further explored the impact of targeting palmitoylation using ZDHHC21 deficient mice or wild‐type mice treated with 2BP and determined intestinal barrier function using mucosal permeability assays. These experiments showed that mice with impaired ZDHHC21 expression or pharmacological inhibition resulted in attenuated intestinal barrier dysfunction caused by thermal injury. Furthermore, H&E staining of small intestine and transmission electron microscopy (TEM) revealed that mice with a genetic interruption of ZDHHC21 had attenuated villus structure disorganization resulting from thermal injury induced inflammation. Taken together, these results suggest an important role of ZDHHC21 in mediating gut hyperpermeability resulting from thermal injury. Support or Funding Information VA Merit IBX000799