Open AccessLaminin‐2 stimulates the proliferation of epithelial cells in a conjunctival epithelial cell line
Author(s) -
Dowgiert J.,
Sosne G.,
KurpakusWheater M.
Publication year - 2004
Publication title -
cell proliferation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.647
H-Index - 74
eISSN - 1365-2184
pISSN - 0960-7722
DOI - 10.1111/j.1365-2184.2004.00292.x
Subject(s) - microbiology and biotechnology , laminin , protein kinase b , integrin , cell growth , mapk/erk pathway , phosphorylation , biology , cell adhesion , chemistry , cell , extracellular matrix , biochemistry
. Laminin‐2 (LN‐2, α2β1γ1) is a basement membrane‐associated laminin isoform usually considered in the context of muscle and nerve tissues. To test the hypothesis that LN‐2 can additionally modulate epithelial cell biology, an analysis of the role of LN‐2 in cell adhesion, activation of signalling intermediates and proliferation was undertaken. A virally transformed human conjunctival epithelial cell line (HC0597) was utilized in this study. Adhesion assays using function‐inhibiting antibodies demonstrated that α3β1 integrin is essential for the rapid attachment of conjunctival epithelial cells to LN‐2. Bromodeoxyuridine (BrdU) incorporation analyses revealed that, compared with LN‐1 or LN‐10, LN‐2 significantly promotes epithelial proliferation. Phosphorylation of the signalling intermediates Erk1/2 and Akt‐1 was observed within 15 min of cell adhesion to LN‐2. Inhibiting α3β1 integrin function decreased total cellular phosphotyrosine levels, specifically inhibited phosphorylation of Erk1/2 and Akt‐1, and dampened the proliferation response of epithelial cells adherent to LN‐2. Inhibition of Erk or Akt activation inhibited cell proliferation in a dose‐dependent manner. However, the inhibition of Erk resulted in a stronger suppression of proliferation compared with Akt inhibition. From these results, it is concluded that human conjunctival epithelial cells adhere to immobilized LN‐2 using α3β1 integrin. α3β1 integrin/LN‐2 signalling, transduced primarily through an Erk pathway, enhances epithelial cell proliferation. These results demonstrate that LN‐2 can impact on epithelial cell biology in addition to nerve and muscle, and provide information regarding the role of this isoform in ocular surface epithelial cells.