Yan L, Frenkel G D
Department of Biological Sciences, Rutgers University, Newark, NJ 07102.
Biol Trace Elem Res. 1994 Oct-Nov;46(1-2):79-89. doi: 10.1007/BF02790069.
Incubation of cells with selenite, under conditions in which there is no effect on cell viability, results in a decrease in the rate of their subsequent attachment to extracellular matrix proteins such as fibronectin (1). The attachment was inhibited by a pentapeptide containing the RGD sequence and by antibody against the cellular fibronectin receptor (alpha 5 beta 1 integrin), indicating that it is receptor-mediated. To investigate whether exposure to selenite has an effect on fibronectin receptors, we assayed for their presence on the cell surface by measuring the ability of cells to attach to a surface that had been coated with antibodies to the receptor. Brief exposure of cells to low concentrations of selenite resulted in a significant decrease in their ability to attach to monoclonal antibodies against the alpha 5 or beta 1 subunits of the fibronectin receptor, as well as to polyclonal antibodies against the complete receptor. This indicates that exposure to selenite results in a decrease in receptors that are present at the cell surface. Exposure of the cells to selenate, selenocystine or selenomethionine did not result in a significant decrease in cell surface receptors. Preincubation of the cells with selenite was required for the effect, indicating that selenite does not directly interfere with receptor structure or function.
在对细胞活力无影响的条件下，用亚硒酸盐孵育细胞，会导致其随后附着于细胞外基质蛋白（如纤连蛋白）的速率降低（1）。这种附着受到含RGD序列的五肽和抗细胞纤连蛋白受体（α5β1整合素）抗体的抑制，表明它是由受体介导的。为了研究暴露于亚硒酸盐是否对纤连蛋白受体有影响，我们通过测量细胞附着于已包被受体抗体的表面的能力，来检测细胞表面是否存在这些受体。将细胞短暂暴露于低浓度的亚硒酸盐，会导致它们附着于抗纤连蛋白受体α5或β1亚基的单克隆抗体以及抗完整受体的多克隆抗体的能力显著降低。这表明暴露于亚硒酸盐会导致细胞表面受体数量减少。将细胞暴露于硒酸盐、硒代胱氨酸或硒代蛋氨酸不会导致细胞表面受体显著减少。该效应需要细胞预先用亚硒酸盐孵育，这表明亚硒酸盐不会直接干扰受体的结构或功能。
