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Injury and EGF mediate the expression of α6β4 integrin subunits in corneal epithelium
Author(s) -
Song Qin Hui,
Singh Rishi P.,
TrinkausRandall Vickery
Publication year - 2000
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/1097-4644(20010301)80:3<397::aid-jcb140>3.0.co;2-w
Subject(s) - microbiology and biotechnology , integrin , epidermal growth factor , cell migration , biology , receptor , wound healing , corneal epithelium , cell culture , epithelium , immunology , biochemistry , genetics
Our goal was to evaluate the role of epidermal growth factor and injury on the expression of integrin subunits alpha6(α6) and beta4(β4). An in vitro wound model was used to evaluate corneal wound repair and cellular migration. Primary rabbit corneal epithelial cell cultures were serum‐starved and injured in the presence or absence of EGF or tyrphostin AG1478, an inhibitor of EGF receptor kinase activity. Repair was monitored morphologically and expression was analyzed using in situ hybridization and immunohistochemistry accompanied by confocal microscopy. The addition of EGF to cell cultures induced a dose‐dependent increase in beta4 mRNA expression but the constitutive expression of α6 was several fold greater. In the wounded cultures there was a rapid change in expression at the edge of the wound that was enhanced with EGF. In our model there was an increase in β4 and α6 protein in migrating cells. Changes in integrin expression were accompanied by a transient increase in activation of the EGF receptor. The addition of tyrphostin inhibited migration of cells and wound repair, the activation of the EGF receptor and phosphorylation of β4 in the cytoplasm. These data indicate that the activation of the EGF receptor plays a critical role in the regulation of integrin receptors and the mediation of cellular migration. J. Cell. Biochem. 80:397–414, 2001. © 2001 Wiley‐Liss, Inc.