Protein kinase C β(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 β(II) in part, for cell growth. PKC β(II) is expressed during cell growth in early glomerulogenesis and inflammatory mediators of glomerular disease induce PKC β(II) expression. We therefore investigated the expression of PKC β(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 β(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 β(II) in proliferative GN suggests a key signaling role for this enzyme in cell proliferation in renal disease.