Interaction between pro-inflammatory and anti-inflammatory cytokines in insulin-producing cells.
Pro-inflammatory cytokines cause beta-cell dysfunction and death. The aim of this study was to investigate the interactions between different pro- and anti-inflammatory cytokines and their effects on apoptotic beta-cell death pathways. Insulin-producing RINm5F cells were exposed to different combinations of cytokines. Gene expression analyses of manganese superoxide dismutase (MnSOD) and inducible nitric oxide synthase (iNOS) were performed by real-time RT-PCR. Cell viability was measured by the MTT assay, NFkappaB activation using a SEAP reporter gene assay, protein expression by western blotting and caspase-3 activity using the DEVD cleavage method. IL-1beta, tumour necrosis factor alpha (TNFalpha) and a combination of all three pro-inflammatory cytokines increased while IFNgamma alone did not affect NFkappaB activity and iNOS gene and protein expression. Interestingly, the anti-inflammatory cytokines IL-4, IL-13 and IL-10 decreased IL-1beta-stimulated NFkappaB activation and iNOS expression. IL-1beta, TNFalpha and the pro-inflammatory cytokine combination also increased MnSOD gene and protein expression. But IL-4, IL-13 and IL-10 did not affect MnSOD expression and did not modulate IL-1beta-stimulated MnSOD expression. Caspase-3 activity was increased by IL-1beta and the pro-inflammatory cytokine combination, and to a lesser extent by TNFalpha. In contrast, IFNgamma had no effect on caspase-3 activity. IL-4, IL-13 and IL-10 decreased caspase-3 activity and increased viability of insulin-producing cells treated with pro-inflammatory cytokines. The anti-inflammatory cytokines counteracted the cytotoxic effects of pro-inflammatory cytokines in insulin-producing cells. This was achieved through the reduction of nitrosative stress. Thus, a balance between the anti-inflammatory and the pro-inflammatory cytokines is of crucial importance for the prevention of pancreatic beta-cell destruction.
Souza
Kleber L A
KL
Hannover Medical School, Institute of Clinical Biochemistry, 30625 Hannover, Germany.
Gurgul-Convey
Ewa
E
Elsner
Matthias
M
Lenzen
Sigurd
S
D000818:Animals; D053148:Caspase 3 / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D016207:Cytokines / Q000494:pharmacology*; D050417:Insulin-Secreting Cells / Q000187:drug effects* / Q000378:metabolism; D007371:Interferon-gamma / Q000494:pharmacology; D053583:Interleukin-1beta / Q000494:pharmacology; D016328:NF-kappa B / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000235:genetics; D019335:Nitroarginine / Q000494:pharmacology; D051381:Rats; D013482:Superoxide Dismutase / Q000235:genetics
D016207:Cytokines; D053583:Interleukin-1beta; D016328:NF-kappa B; D019335:Nitroarginine; D007371:Interferon-gamma; D052247:Nitric Oxide Synthase Type II; D013482:Superoxide Dismutase; D053148:Caspase 3