Effects of tumour necrosis factor alpha and interleukin 1 beta on the proliferation of cultured glomerular epithelial cells.
Rat glomerular epithelial cells were cultured with human monocyte supernatant or with recombinant cytokines. A primary glomerular culture and a glomerular epithelial cell culture were made; supernatant from monocyte cultures derived from healthy humans, and recombinant tumour necrosis factor alpha (TNF alpha) or recombinant interleukin 1 beta (IL-1 beta) were added. Cell proliferation rates were assayed by the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay. In serum-free media, consistent proliferation of glomerular epithelial cells (GEC) was observed throughout the 3 week culture period. Significant growth-stimulatory effects were induced by lipopolysaccharide-treated monocyte conditioned medium and by 1-50 ng/ml of TNF alpha, growth being up to 400% more than in the control culture. The effect of TNF alpha depended mainly on its interaction with epidermal growth factor (EGF). In contrast to TNF alpha, IL-1 beta inhibited GEC proliferation; this was due to the early appearance and proliferation of mesangial cells, despite the culture being serum-free. This study showed that activated monocytes secrete growth factors for GEC in vitro, and that interaction between both TNF alpha and IL-1 beta and between TNF alpha and EGF can modulate GEC proliferation. These findings suggest that, under pathological conditions, monocytes or macrophages affect GEC proliferation, probably being involved in crescent formation.
Yanagisawa
M
M
Arc Clinic of Cardiology and Nephrology, Akita, Japan.
Imai
H
H
Fukushima
Y
Y
Yasuda
T
T
Miura
A B
AB
Nakamoto
Y
Y
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D004847:Epithelial Cells; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology*; D007678:Kidney Glomerulus / Q000166:cytology*; D008297:Male; D008854:Microscopy, Electron; D009000:Monocytes; D051381:Rats; D017208:Rats, Wistar; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D007375:Interleukin-1; D014409:Tumor Necrosis Factor-alpha