Tumor necrosis factor-alpha induces the phosphorylation of 28kDa stress proteins in endothelial cells: possible role in protection against cytotoxicity?

Tumor necrosis factor-alpha has been shown to rapidly increase the phosphorylation of three 28 kDa proteins in bovine aortic endothelial cells but not in L929 cells. Tumor necrosis factor-alpha induces the necrosis of the latter cells but not of the former. Arsenite enhanced the phosphorylation of the same 28kDa proteins as tumor necrosis factor-alpha in the endothelial cells. As stress proteins often play a protective role, we suggest that the phosphorylation of these proteins in endothelial cells may be responsible for the resistance of these cells to tumor necrosis factor-alpha.