EFFECTS OF EXTRACELLULAR MATRICES ON TUBE FORMATION OF CULTURED RAT HEPATIC SINUSOIDAL ENDOTHELIAL-CELLS

To determine the effects of extracellular matrices on the function and morphology of hepatic sinusoidal endothelial cells, isolated rat hepa tic sinusoidal endothelial cells were cultured in three-dimensional fa shion on collagen gel containing various extracellular matrix componen ts. Cells cultured on type I collagen gel with or without type TV coll agen formed a cobblestone appearance on the surface of the gel, Cells cultured on laminin-containing type I collagen gel invaded the gel and exhibited three-dimensional tube formation with a decreased number of characteristic endothelial pores, Morphometrically, there was a signi ficant relationship between the length of the tube formed and the conc entration of laminin in the type I collagen gel, Cells cultured on Mat rigel, which contains high concentrations of laminin, type IV collagen , fibroblast growth factor, tissue plasminogen activator, and other gr owth factors, formed a great number of tubes into a network on the sur face of the gel, as is observed in in situ hepatic sinusoidal endothel ial cells. Ultrastructurally, tube-forming endothelial cells cultured on Matrigel had many endothelial pores on the cell surface, with tubes (approximately 10 mu m in diameter) formed by two or three hepatic si nusoidal endothelial cells. These results indicated that extracellular matrix components, especially laminin, induced the formation of tubes in cultured rat hepatic sinusoidal endothelial cells. Tube-forming si nusoidal endothelial cells cultured on Matrigel could provide more adv antages than the two-dimensional culture model for investigating the f unction and morphology of these cells in vitro.