Differential effects of FMLP-activated neutrophils from patients with IgA nephropathy enhanced endothelin 1 production of glomerular mesangial cells.
BACKGROUND
Neutrophil infiltration in the glomeruli is common in patients with IgA nephropathy (IgAN). The pathogenetic roles of the infiltrated neutrophils and their relationship with glomerular mesangial cells, however, are not clear.


METHODS
We examined the effects of coculture with N-formyl-methionyl-leucyl-phenylalanine (FMLP) activated neutrophils on the viability, endothelin 1 (ET-1) production, and ET-1 mRNA expression of rat glomerular mesangial cells. Neutrophils were isolated from 15 IgAN patients, from 13 patients with non-IgA mesangial proliferative glomerulonephritis (MsPGN), and from 10 normal controls.


RESULTS
The ET-1 production by mesangial cells was significantly higher after stimulation with FMLP-activated neutrophils from IgAN patients than that of MsPGN patients and normal controls, and this effect was significantly abolished by pretreating mesangial cells with superoxide dismutase and partly abolished by catalase. The ET-I mRNA expression of mesangial cells showed a parallel increase with ET-1 protein. The trypan blue exclusion test showed significant mesangial cell death after stimulation with FMLP-activated neutrophils as compared with quiescent neutrophils, and the cell death was also prevented by superoxide dismutase but not catalase. The FMLP-activated neutrophils from IgAN patients produced more superoxide than those of MsPGN patients and normal controls.


CONCLUSIONS
The FMLP-activated neutrophils from patients with IgAN have differential effects in enhancing the cell death and the ET-1 production of glomerular mesangial cells through the release of superoxide.
Chen
H C
HC
Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan. chenghc@cc.kmu.edu.tw
Guh
J Y
JY
Chang
J M
JM
Lai
Y H
YH
D000328:Adult; D018920:Coculture Techniques; D019332:Endothelin-1 / Q000096:biosynthesis* / Q000235:genetics; D005260:Female; D005920:Glomerular Mesangium / Q000378:metabolism*; D005922:Glomerulonephritis, IGA / Q000097:blood / Q000378:metabolism*; D006801:Humans; D008297:Male; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology*; D018375:Neutrophil Activation; D009504:Neutrophils / Q000187:drug effects*; D012333:RNA, Messenger / Q000096:biosynthesis; D013481:Superoxides / Q000378:metabolism; D014343:Trypan Blue; D015854:Up-Regulation
D019332:Endothelin-1; D012333:RNA, Messenger; D013481:Superoxides; D009240:N-Formylmethionine Leucyl-Phenylalanine; D014343:Trypan Blue