Premium
Integrin‐mediated stimulation of monocyte chemotactic protein‐1 expression
Author(s) -
Fabio Marra,
Sabrina Pastacaldi,
Roberto Giulio Romanelli,
Massimo Pinzani,
Piero Ticali,
Vinicio Carloni,
Giacomo Laffi,
Paolo Geñtilini
Publication year - 1997
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(97)01004-1
Subject(s) - fibronectin , integrin , microbiology and biotechnology , chemotaxis , extracellular matrix , integrin alpha m , monocyte , secretion , collagen receptor , hepatic stellate cell , chemistry , biology , receptor , immunology , biochemistry , endocrinology
We investigated whether activation of integrin receptors could modulate the expression of monocyte chemotactic protein‐1 (MCP‐1) in human hepatic stellate cells (HSC), mesenchymal cells responsible for extracellular matrix synthesis within the liver. When compared to non‐adherent cells, HSC plated on collagen types I or IV, or fibronectin, showed increased MCP‐1 gene expression and protein secretion in the conditioned medium. Increased MCP‐1 secretion was also observed when cells were plated on dishes coated with a monoclonal antibody directed against the β1‐integrin subunit, demonstrating that ligation of β1‐integrins is sufficient to stimulate MCP‐1 expression. Conversely, integrin‐independent cell adhesion on poly‐ l ‐lysine did not modify MCP‐1 secretion. Disruption of the actin cytoskeleton by cytochalasin D blocked the collagen‐dependent increase in MCP‐1 secretion. Chemotactic assay of HSC‐conditioned medium showed that HSC plated on collagen secrete higher amounts of chemotactic factors for lymphomonocytes, and that MCP‐1 accounts for the great majority of this effect. These findings indicate a novel mechanism of MCP‐1 regulation possibly relevant in those conditions where HSC interact with an altered extracellular matrix.