抄録
Transforming growth factor β inhibits the proliferation of human umbilical vein endothelial cells (HUVEC) depending on the isoform of TGF/β and culture conditions. When the cells are plated on substratum without pretreatment with extracellular matrices (ECM), the effect of TGFβ1 is biphasic while TGFβ2 inhibits the growth of HUVEC dose-dependently. The growth inhibition of HUVEC by TGFβ is not linked to a direct effect on the entry to S-phase DNA synthesis. In HUVEC cultured on the substratum coated with gelatin or collagen, growth inhibition by TGFβ is not observed. In addition, the susceptibility to TGFβ is reduced significantly in HUVEC at later cell passages. Cross-linking studies with radiolabeled TGFβ1 revealed is oform-specific 180 and 80 kDa TGFβ binding proteins on HUVEC. Phosphatidylinositol-specific phospholipase C induces the release of the 180 kDa protein from the cells, suggesting that the 180 kDa protein is attached to the cell membrane through a phosphatidylinositol anchor. Pretreatment of the substratum with ECM and changes in the number of cell passages did not alter the expression of TGFβ1-binding proteins in HUVEC. The data suggest that the susceptibility of HUVEC to TGFβ is not regulated at the level of receptor/binding proteins, and that growth inhibition of HUVEC by TGFβ is linked to the regulation of ECM required for the interaction between the cells and the substratum.
