Open AccessOverexpression of BCL-2 in the Intestinal Epithelium Prevents Sepsis-Induced Gut Barrier Dysfunction via Altering Tight Junction Protein Expression
Author(s) -
Shunsuke Otani,
Takehiko Oami,
Benyam P. Yoseph,
Nathan J. Klingensmith,
Ching-Wen Chen,
Zhe Liang,
Craig M. Coopersmith
Publication year - 2019
Publication title -
shock
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.095
H-Index - 117
eISSN - 1540-0514
pISSN - 1073-2322
DOI - 10.1097/shk.0000000000001463
Subject(s) - occludin , tight junction , intestinal permeability , claudin , sepsis , apoptosis , intestinal epithelium , fluorescein isothiocyanate , genetically modified mouse , biology , endocrinology , medicine , andrology , chemistry , immunology , transgene , epithelium , microbiology and biotechnology , pathology , biochemistry , gene , physics , quantum mechanics , fluorescence
Sepsis induces both intestinal hyperpermeability and epithelial apoptosis. While each has been implicated in mediating sepsis mortality, the relationship between these two processes is unclear. We hypothesized that preventing intestinal apoptosis would prevent gut barrier dysfunction. To test this hypothesis, transgenic mice that overexpress the anti-apoptotic protein Bcl-2 in the gut epithelium (Fabpl-Bcl-2 mice) and wild-type (WT) mice were subjected to sham laparotomy or cecal ligation and puncture and orally gavaged with fluorescein isothiocyanate conjugated-dextran (FD-4) 5 h before sacrifice. Serum FD-4 concentration was assayed to measure intestinal permeability, and jejunal tight junctions were assayed for mRNA and protein expression. Baseline FD-4 concentration was similar between WT and Fabpl-Bcl-2 mice. Intestinal permeability increased 6, 12, 24, and 48 h following sepsis in WT mice; however, FD-4 concentration was significantly lower at each timepoint in Fabpl-Bcl-2 mice. In addition, there were no statistically significant changes in permeability between septic and sham transgenic mice. Intestinal mRNA expression of claudin 3, claudin 5, and occludin was lower in septic Fabpl-Bcl-2 mice, while claudin 4 mRNA levels were higher in Fabpl-Bcl-2 mice. In contrast, no differences were detected in claudins 2, 7, 15, JAM-A, or ZO-1. Protein levels followed the same trend for all tight junction mediators different between WT and Fabpl-Bcl-2 mice except occludin was significantly higher in transgenic mice. Together these results demonstrate that decreasing intestinal epithelial apoptosis prevents hyperpermeability following sepsis via tight junction alterations which may be at least partially responsible for improved survival conferred by Bcl-2 overexpression.