Expression of cell-matrix adhesion molecules in the liver and their modulation during fibrosis.

Abstract

The molecular interactions between cells and the constituents of the extracellular matrix are mediated through specialized plasma membrane proteins, which belong to various classes of cell adhesion molecules. The pattern of expression of cell-matrix adhesion molecules is very distinctive in the liver. In particular, most of the cell-matrix adhesion molecules constitutionnally expressed by epithelial and endothelial cells behave as inducible molecules on hepatocytes and sinusoidal endothelial cells. They are absent in the normal state and are up-regulated during the fibrotic process. Liver cells therefore offer a unique possibility to study the regulation of cell-matrix adhesion molecules and to evaluate their relevance to the physiopathology of the fibrotic process. We will first describe the main classes of cell-matrix adhesion molecules, then review the current knowledge about the expression of these molecules in the normal and fibrotic human liver, and finally address some questions for future research.