Abstract
Abstract: :
Purpose: RPE cells play a key role in the development of several retinal wound healing pathologies. ABL binds the Thomsen–Friedenreich (TF) antigen, a glycoprotein on the cell membrane, that is expressed only in dedifferentiated RPE cells which have a major role in these pathologies. We have previously shown that agaricus bisporus, a lectin from the common edible mushroom inhibits RPE proliferation and contraction of type I collagen matrices in in vitro models of wound healing. RPE cell behaviour is directly influenced by the surrounding extracellular matix (ECM). We therefore investigated the direct effect of ABL on RPE cell adhesion to a number of the ECM proteins found in retinal wound healing. Methods: Various extracellular proteins (collagen types I, III, IV, Laminin, fibronectin and vitronectin) were assessed for adhesion of ARPE19 cells. Cells were cultured for 24 hours prior to preincubation with different concentrations of ABL. Controls will consist of either the preincubation of 5 mg/ml asialomucin (ABL inhibitor) with the cells or the ABL prior to addition of the ABL to the compartment. After 1 hour of incubation in a 5% CO2–humidified atmosphere at 37°C, the cellular morphology and adhesion of the cells was assessed by inverted photomicroscopy. Results: RPE adhered to all substrates tested. ABL significantly inhibited adhesion of RPE cells to Col I and III, fibronectin and vitronectin when compared to controls at 20ug/ml and above. Adhesion to basement membrane proteins Laminin and collagen IV was significantly increased with incubation of cells with ABL 10ug/ml and above. This increase in adhesion was abolished in the presence of ASF. Conclusions: ABL exerts different effects on RPE cell adhesion to various ECM proteins indicating the effect may be through action on different ECM receptors.
Keywords: retinal pigment epithelium • wound healing • extracellular matrix