Blocking of alpha 5 integrin stimulates production of TGF-beta and PAI-1 by human mesangial cells.
Expression of integrin, which mediates cell-matrix interaction, is affected by several cytokines, in particular by transforming growth factor-beta (TGF-beta). However, it is unknown whether, in an opposite way, a specific integrin is involved in cytokine synthesis. We tested this hypothesis. Function-blocking anti-alpha 5 integrin (fibronectin receptor) antibody increased TGF-beta secretion in growth-arrested human mesangial cells (2.3-fold) compared with control IgG or anti-alpha v beta 3 integrin (receptor for several matrix proteins) antibody. It also increased the secretion of plasminogen activator inhibitor-1 (PAI-1), a protein associated with matrix increase, by 3.2-fold. The increase in PAI-1 secretion induced by anti-alpha 5 integrin antibody was not abrogated by anti-TGF-beta neutralizing antibody. These results indicate that function-blocking of anti-alpha 5 integrin stimulates TGF-beta as well as PAI-1 production, suggesting that alpha 5 integrin is involved in fibrotic process. Function-modulation of a specific integrin thus appears to play a role in glomerular remodeling.
Matsumoto
Naoki
N
Department of Nephrology, Osaka City University Graduate School of Medicine, 1-4-3, Asahi-machi, Abeno-ku, Osaka 545-8585, Japan.
Ishimura
Eiji
E
Koyama
Hidenori
H
Tanaka
Shinji
S
Imanishi
Yasuo
Y
Shioi
Atsushi
A
Inaba
Masaaki
M
Nishizawa
Yoshiki
Y
D000906:Antibodies / Q000494:pharmacology; D002478:Cells, Cultured; D005920:Glomerular Mesangium / Q000378:metabolism*; D006801:Humans; D039482:Integrin alpha5 / Q000276:immunology / Q000502:physiology*; D017395:Plasminogen Activator Inhibitor 1 / Q000096:biosynthesis*; D016212:Transforming Growth Factor beta / Q000096:biosynthesis*
D000906:Antibodies; D039482:Integrin alpha5; D017395:Plasminogen Activator Inhibitor 1; D016212:Transforming Growth Factor beta