Interleukin-10 is a mesangial cell growth factor in vitro and in vivo.
Macrophages are involved in the pathogenesis of mesangioproliferative glomerulonephritis. As macrophages are known to produce interleukin-10 (IL-10), we investigated the effect of recombinant murine IL-10 (rIL-10) on mesangial cell growth. In vitro studies were performed using the rat 1097 mesangial cell line. These cells exhibited a dose-dependent proliferative response to rIL-10 (23% to 70% increases at 80 ng/mL; p < 0.01), as assessed by both 3H-thymidine uptake and cell count. This effect was inhibited by preincubation of rIL-10 with a neutralizing anti-IL-10 antibody. When added to cultures of growth-arrested 1097 cells, IL-10 induced dose-dependent proliferation that paralleled the effects of platelet-derived growth factor. Incubation with a neutralizing anti-IL-10 Ab for 48 hours reduced 3H-thymidine uptake (median, 27% decreases; range, 2% to 56% decreases) versus a control Ab; p < 0.05). Rat mesangial cells were also shown to express IL-10 mRNA and protein, as determined by Northern blotting and immunostaining, thereby suggesting a role for IL-10 in autocrine mesangial cell growth. To examine the effects of IL-10 in vivo, inbred male Sprague-Dawley rats were given subcutaneous rIL-10 (0.5 mg/kg) for 3 (n = 6), 7 (n = 3), or 14 days (n = 4), or vehicle control, then killed. IL-10 administration induced a transient reduction in creatinine clearance of 35% at Day 3 (p < 0.01). Following IL-10 administration, an increase in glomerular cellularity was seen, which was maximal at Day 3 (82.7 +/- 5.9 nuclei/glomerular cross section versus control 64.6 +/- 4.6, 28% increases; p < 0.001) and maintained at Day 14 (23% increases; p < 0.01). Immuno-histochemical staining for proliferating cell nuclear antigen demonstrated an increased number of proliferating cells per glomerular cross section at day 3 (48% increases versus controls; p < 0.05). Staining for alpha-smooth-muscle actin showed significant labeling only in the glomeruli of IL-10-treated animals; double-labeling with an anti-proliferating cell nuclear antigen Ab demonstrated that some of these mesangial cells were proliferating. Collectively, these results suggest that IL-10 is a growth factor for rat mesangial cells both in vitro and in vivo.
Chadban
S J
SJ
Department of Nephrology, Monash Medical Centre, Clayton, Victoria, Australia.
Tesch
G H
GH
Foti
R
R
Atkins
R C
RC
Nikolic-Paterson
D J
DJ
D000199:Actins / Q000096:biosynthesis; D000818:Animals; D019138:Antibodies, Blocking / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D005920:Glomerular Mesangium / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D006133:Growth Substances / Q000494:pharmacology*; D007279:Injections, Subcutaneous; D016753:Interleukin-10 / Q000008:administration & dosage* / Q000096:biosynthesis / Q000276:immunology / Q000494:pharmacology*; D008297:Male; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012194:RNA-Directed DNA Polymerase; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000276:immunology / Q000494:pharmacology
D000199:Actins; D019138:Antibodies, Blocking; D006133:Growth Substances; D011994:Recombinant Proteins; D016753:Interleukin-10; D012194:RNA-Directed DNA Polymerase