p120-catenin is essential for maintenance of barrier function and intestinal homeostasis in mice
Whitney G. Smalley-Freed, … , Robert J. Coffey, Albert B. Reynolds
Whitney G. Smalley-Freed, … , Robert J. Coffey, Albert B. Reynolds
Published May 17, 2010
Citation Information: J Clin Invest. 2010;120(6):1824-1835. https://doi.org/10.1172/JCI41414.
View: Text | PDF
Research Article Gastroenterology

p120-catenin is essential for maintenance of barrier function and intestinal homeostasis in mice

Abstract

Epithelial-cadherin (E-cadherin) is a master organizer of the epithelial phenotype. Its function is regulated in part by p120-catenin (referred to herein as p120), a cytoplasmic binding partner that directly regulates cadherin stability. As it has been suggested that cadherins have a role in inflammatory bowel disease (IBD), we sought to investigate this further by assessing the effect of p120 deficiency in mouse small intestine and colon. p120 conditional KO mice were superficially normal at birth but declined rapidly and died within 21 days. Cell-cell adhesion defects and inflammation led to progressive mucosal erosion and terminal bleeding, similar to what is observed in a dominant-negative cadherin mouse model of IBD. Additionally, selective loss of adherens junctions and accumulation of atypical COX-2–expressing neutrophils in p120-null areas of the colon were observed. To elucidate the mechanism, direct effects of p120 deficiency were assessed in vitro in a polarizing colon cancer cell line. Notably, transepithelial electrical resistance was dramatically reduced, neutrophil binding was increased 30 fold, and levels of COX-2, an enzyme associated with IBD, were markedly increased in neutrophils. Our data suggest that p120 loss disrupts the neonatal intestinal barrier and amplifies neutrophil engagement and that these changes lead to catastrophic inflammation during colonization of the neonatal gut with bacteria and other luminal antigens. Thus, we conclude that p120 has an essential role in barrier function and epithelial homeostasis and survival in the intestine.

Authors

Whitney G. Smalley-Freed, Andrey Efimov, Patrick E. Burnett, Sarah P. Short, Michael A. Davis, Deborah L. Gumucio, M. Kay Washington, Robert J. Coffey, Albert B. Reynolds

×

Figure 8

p120 KD in vitro in HCA7 cells abolishes barrier function and increases neutrophil attachment.

Options: View larger image (or click on image) Download as PowerPoint
p120 KD in vitro in HCA7 cells abolishes barrier function and increases ...
(A) TER was measured over time during neutrophil migration (with and without fMLP) across control (pLL-GFP) and p120-deficient (pLL-hp120i-GFP) HCA7 monolayers. TER was measured in Ohms and normalized to reflect the fraction of total TER generated by control HCA7 monolayers at time 0 (before addition of neutrophils). TER was very low or absent in monolayers generated with p120-deficient HCA7 cells. med, media. (B) To visualize tight junctions, the control and p120-deficient HCA7 monolayers used to generate the TER data in A were immunostained with an antibody directed against ZO-1. Scale bar: 20 μm. (C) Neutrophil transmigration (with fMLP) was measured on WT and p120-deficient HCA7 monolayers. Neutrophil transmigration was unaffected by p120 KD. (D–F) The experiment in C was repeated with an incubation time of 2 hours. Filters were washed vigorously and neutrophil attachment to WT HCA7 cells (D) or p120-deficient HCA7 cells (E) was assayed by direct immunofluorescent staining. The results are quantified in F. Neutrophil attachment to the p120-deficient HCA7 monolayer was increased 30 fold. Data represent mean ± SD. Original magnification, ×20 (B, D, and E).