Colon-specific delivery of a probiotic-derived soluble protein ameliorates intestinal inflammation in mice through an EGFR-dependent mechanism
Fang Yan, … , Keith T. Wilson, D. Brent Polk
Fang Yan, … , Keith T. Wilson, D. Brent Polk
Published May 23, 2011
Citation Information: J Clin Invest. 2011;121(6):2242-2253. https://doi.org/10.1172/JCI44031.
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Research Article

Colon-specific delivery of a probiotic-derived soluble protein ameliorates intestinal inflammation in mice through an EGFR-dependent mechanism

Abstract

Probiotic bacteria can potentially have beneficial effects on the clinical course of several intestinal disorders, but our understanding of probiotic action is limited. We have identified a probiotic bacteria–derived soluble protein, p40, from Lactobacillus rhamnosus GG (LGG), which prevents cytokine-induced apoptosis in intestinal epithelial cells. In the current study, we analyzed the mechanisms by which p40 regulates cellular responses in intestinal epithelial cells and p40’s effects on experimental colitis using mouse models. We show that the recombinant p40 protein activated EGFR, leading to Akt activation. Activation of EGFR by p40 was required for inhibition of cytokine-induced apoptosis in intestinal epithelial cells in vitro and ex vivo. Furthermore, we developed a pectin/zein hydrogel bead system to specifically deliver p40 to the mouse colon, which activated EGFR in colon epithelial cells. Administration of p40-containing beads reduced intestinal epithelial apoptosis and disruption of barrier function in the colon epithelium in an EGFR-dependent manner, thereby preventing and treating DSS-induced intestinal injury and acute colitis. Furthermore, p40 activation of EGFR was required for ameliorating colon epithelial cell apoptosis and chronic inflammation in oxazolone-induced colitis. These data define what we believe to be a previously unrecognized mechanism of probiotic-derived soluble proteins in protecting the intestine from injury and inflammation.

Authors

Fang Yan, Hanwei Cao, Timothy L. Cover, M. Kay Washington, Yan Shi, LinShu Liu, Rupesh Chaturvedi, Richard M. Peek Jr., Keith T. Wilson, D. Brent Polk

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Figure 1

p40 activates EGFR, leading to Akt activation in colon epithelial cells.

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p40 activates EGFR, leading to Akt activation in colon epithelial cells....
(A–D) YAMC, HT-29, or Egfr–/– MCE cells were treated with p40 or heat-inactivated p40 at the indicated concentrations for 1 hour, or with EGF (10 ng/ml) for 5 minutes. (E) Colon explants derived from 6- to 8-week-old WT and Egfrwa5 mice on a C57BL/6 background were cultured in DMEM containing 0.5% FBS and treated with p40 (10 ng/ml) for 1 hour, with or without 1-hour pretreatment using an EGFR tyrosine kinase inhibitor, AG1478 (150 nM). AG1478 was maintained during the entire course of cytokine treatment. EGFR and Akt phosphorylation was detected by Western blot analysis of cellular lysates with anti–phospho-EGFR (Tyr1068) and anti–phospho-Akt (Ser473) antibodies, respectively. Anti-actin antibody was used as a loading control. In D and E, lanes were run on the same gel but were noncontiguous, as indicated by the white lines. Data in this and subsequent figures are representative of at least 5 separate experiments.