NUCLEAR FACTOR-KAPPA-B MEDIATES INDUCTION OF VASCULAR CELL-ADHESION MOLECULE-1 IN GLOMERULAR MESANGIAL CELLS

Cultured glomerular mesangial cells (GMCs) can be activated at the tra nscriptional level by a variety of physiologically relevant factors in cluding cytokines, endotoxin and glycosylated end products. The mechan ism with which the signal is transduced from the membrane to the nucle us of these cells is largely unclear. In vascular endothelial cells, t he signal transduction pathway involves activation of the pleuripotent transcription factor, NF-kappa B, and leads to increased expression o f a variety of genes including vascular cell adhesion molecule-1 (VCAM -1). Here, we demonstrate that TNF-alpha and IL-1 beta transiently ind uced VCAM-1 mRNA expression in a time dependent manner. TNF alpha also induced the specific interaction of proteins from GMC nuclei with an oligonucleotide bearing the NF-kappa B binding sites in the VCAM-1 pro moter. Electrophoretic mobility shift and supershift analysis indicate d that the p65 subunit of NF-kappa B is a component of this induced co mplex. Finally, reporter activity driven by a VCAM-1 promoter-chroramp henicol acetyltransferase reporter construct increased 8-10 fold follo wing TNF-alpha incubation, or p65 cotransfection. Thus, the p65 subuni t of NF-kappa B is activated in GMCs exposed to cytokine and can media te induction of gene expression. (C) 1995 Academic Inc.