[Significance of membrane attack complex inhibitory factor expression in cultured human glomerular epithelial cells].
Membrane attack complex (MAC) inhibitory factor (MACIF) is a 20-kD membrane protein that inhibits MAC formation on homologous cells. Until recently, a functional role of MACIF had been demonstrated in erythrocytes. Therefore, we have focused on the fact that glomerular epithelial cells (GECs) are the primary target of MAC-mediated damage in rat Heymann's nephritis model of human membranous nephropathy. Using immunocytochemistry and western blotting we have shown that MACIF is expressed in cultured human GECs. Phosphatidyl-inositol (PI)-phospholipase C (PLC) reduced MACIF expression in these cells, suggesting that MACIF is a PI-linked membrane protein in GECs. In addition, we elucidated that MACIF protects GECs against complement-mediated lysis. These findings suggest that MACIF expressed on GECs plays an important role in the protection of GECs against complement mediated-cellular damage in vivo.
Tsutsui
T
T
Department of Medicine, Kidney Center, Tokyo Women's Medical College, Japan.
Nitta
K
K
Yumura
W
W
Nihei
H
H
D018957:CD59 Antigens; D002478:Cells, Cultured; D015938:Complement Membrane Attack Complex / Q000037:antagonists & inhibitors*; D004847:Epithelial Cells; D004848:Epithelium / Q000378:metabolism; D006801:Humans; D007678:Kidney Glomerulus / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*
D018957:CD59 Antigens; D015938:Complement Membrane Attack Complex; D011506:Proteins