Protein kinase C beta II isoform is up-regulated in human proliferative glomerulonephritis.

Cell proliferation is a predominant feature in glomerulonephritis (GN). Recent work has suggested that protein kinase C (PKC) isoforms are responsible, specifically, PKC beta II in part, for cell growth. PKC beta II is expressed during cell growth in early glomerulogenesis and inflammatory mediators of glomerular disease induce PKC beta II expression. We therefore investigated the expression of PKC beta II in kidney biopsy specimens from patients with various types of proliferative (n = 41), nonproliferative GN (n = 23), and in structurally normal kidneys (n = 15). PKC beta II immunoreactivity was exclusively found in proliferative GN whereas PKC expression was not detected in normal glomerular and in nonproliferative disease states. The consistent expression of PKC beta II in proliferative GN suggests a key signaling role for this enzyme in cell proliferation in renal disease.