First Author | Chignalia AZ | Year | 2015 |
Journal | Am J Pathol | Volume | 185 |
Issue | 5 | Pages | 1251-63 |
PubMed ID | 25773174 | Mgi Jnum | J:220680 |
Mgi Id | MGI:5635935 | Doi | 10.1016/j.ajpath.2015.01.022 |
Citation | Chignalia AZ, et al. (2015) p120-Catenin Expressed in Alveolar Type II Cells Is Essential for the Regulation of Lung Innate Immune Response. Am J Pathol 185(5):1251-63 |
abstractText | The integrity of the lung alveolar epithelial barrier is required for the gas exchange and is important for immune regulation. Alveolar epithelial barrier is composed of flat type I cells, which make up approximately 95% of the gas-exchange surface, and cuboidal type II cells, which secrete surfactants and modulate lung immunity. p120-catenin (p120; gene symbol CTNND1) is an important component of adherens junctions of epithelial cells; however, its function in lung alveolar epithelial barrier has not been addressed in genetic models. Here, we created an inducible type II cell-specific p120-knockout mouse (p120EKO). The mutant lungs showed chronic inflammation, and the alveolar epithelial barrier was leaky to (125)I-albumin tracer compared to wild type. The mutant lungs also demonstrated marked infiltration of inflammatory cells and activation of NF-kappaB. Intracellular adhesion molecule 1, Toll-like receptor 4, and macrophage inflammatory protein 2 were all up-regulated. p120EKO lungs showed increased expression of the surfactant proteins Sp-B, Sp-C, and Sp-D, and displayed severe inflammation after pneumonia caused by Pseudomonas aeruginosa compared with wild type. In p120-deficient type II cell monolayers, we observed reduced transepithelial resistance compared to control, consistent with formation of defective adherens junctions. Thus, although type II cells constitute only 5% of the alveolar surface area, p120 expressed in these cells plays a critical role in regulating the innate immunity of the entire lung. |