Hepatocyte-matrix interaction

Abstract

Various components of extracellular matrices have unique patterns of distribution in the liver, which change under hepatic regeneration and in pathological conditions. In vitro studies using isolated hepatocytes maintained in culture on different matrix proteins or tissue biomatrices revealed that the matrix influences the biochemical activity of hepatocytes in culture on a selective basis. Hepatocyte-matrix interactions are mediated by specific receptors for matrix proteins belonging to both integrin and non-integrin group of cell surface molecules. The level of α1β1 integrin, which is a common receptor for Col IV and Ln in liver appears to change under hepatic regeneration; cat ions appear to modulate its interaction with Col IV and Ln in a differential manner. A number of other integrin receptors including that for fibronectin (α5β1) and vitronectin (α1β1) are also present in liver. Apart from integrin receptors, non-integrin receptors such as 67 kDa laminin binding protein, 68 kDa collagen IV binding protein, 110 kDa Fn receptor are also present in liver cells. HSPG present on the hepatocyte surface also appears to have an augmenting effect in mediating cell adhesion. Although matrix components appear to exert their effect through interaction with matrix receptors on cell surface, details about the intracellular signalling process in liver cells are not clear.