Inhibition of protein kinase C counteracts TNFalpha-induced intercellular adhesion molecule 1 expression and fluid phase endocytosis on brain microvascular endothelial cells.

TNFalpha (100 U/ml, 24 h) upregulated intercellular adhesion molecule 1 (ICAM1) expression and fluid phase endocytosis (FPE) of horseradish peroxidase on brain microvascular endothelial cell (BMEC) culture. The protein kinase C (PKC) inhibitor staurosporin (0. 5-10 nM) antagonized ICAM1 expression and FPE due to TNFalpha, whereas the protein kinase A inhibitor H89 (0.5-10 nM) did not. These findings indicate that a PKC-dependent mechanism may affect TNFalpha signalling on different barrier properties of BMECs.