Cycloprodigiosin up-regulates inducible nitric oxide synthase gene expression in hepatocytes stimulated by interleukin-1beta.
The proinflammatory cytokine interleukin-1beta stimulates inducible nitric oxide synthase (iNOS) gene expression in hepatocytes via activation of a transcription factor, nuclear factor-kappaB (NF-kappaB). Nitric oxide has diverse cytoprotective and toxic effects. Cycloprodigiosin is an anticancer drug that induces apoptosis through NF-kappaB-dependent mechanisms. This study investigated whether cycloprodigiosin influenced NF-kappaB activation and induction of iNOS by interleukin-1beta. Cycloprodigiosin alone had no effect on NO production by primary cultured rat hepatocytes. Simultaneous addition of cycloprodigiosin and interleukin-1beta markedly stimulated the induction of iNOS mRNA and protein compared with addition of interleukin-1beta alone, resulting in overproduction of NO. Cycloprodigiosin had no effect on degradation of the inhibitory subunit of NF-kappaB (IkappaBalpha), but lessened the recovery of IkappaBalpha levels. The electrophoretic mobility shift assay revealed that cycloprodigiosin caused an increase of NF-kappaB activation. Consistent with this observation, cycloprodigiosin promoted the translocation of p65 (a subunit of NF-kappaB) to the nucleus. Furthermore, this drug enhanced expression of the type 1 interleukin-1 receptor, and this action showed similar concentration-dependence to its induction of iNOS. These results indicate that cycloprodigiosin up-regulates the induction of iNOS by increasing NF-kappaB activation, at least partly through enhancement of type 1 interleukin-1 receptor expression. By regulating the expression of NF-kappaB-dependent genes, such as iNOS, cycloprodigiosin administration may increase NO production during hepatic injury.
Teshima
Shigeru
S
The First Department of Surgery, Kansai Medical University, Osaka 570-8506, Japan.
Nakanishi
Hideki
H
Kamata
Keiko
K
Kaibori
Masaki
M
Kwon
A-Hon
AH
Kamiyama
Yasuo
Y
Nishizawa
Mikio
M
Ito
Seiji
S
Okumura
Tadayoshi
T
D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured / Q000187:drug effects / Q000378:metabolism; D004790:Enzyme Induction / Q000187:drug effects; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D020672:I-kappa B Proteins / Q000378:metabolism; D007211:Indoles / Q000494:pharmacology*; D007375:Interleukin-1 / Q000494:pharmacology*; D008297:Male; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000378:metabolism; D009569:Nitric Oxide / Q000096:biosynthesis; D019001:Nitric Oxide Synthase / Q000096:biosynthesis* / Q000235:genetics; D052247:Nitric Oxide Synthase Type II; D021381:Protein Transport; D011758:Pyrroles / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D017472:Receptors, Interleukin-1 / Q000096:biosynthesis / Q000187:drug effects / Q000235:genetics; D011994:Recombinant Proteins / Q000494:pharmacology; D013268:Stimulation, Chemical; D051996:Transcription Factor RelA
D020672:I-kappa B Proteins; D007211:Indoles; D007375:Interleukin-1; D016328:NF-kappa B; C000606204:NFKBIA protein, human; C000606206:Nfkbia protein, rat; D011758:Pyrroles; D017472:Receptors, Interleukin-1; D011994:Recombinant Proteins; D051996:Transcription Factor RelA; D000072000:NF-KappaB Inhibitor alpha; D009569:Nitric Oxide; C108328:cycloprodigiosin; C496319:NOS2 protein, human; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat