Inhibition by (+/-)-indenestrol A of interferon gamma-stimulated nitric oxide formation in murine macrophage RAW 264.7 cells.
We examined the effects of (+/-)-indenestrol A (IA), an antioxidative and superoxide-producing metabolite of diethylstilbestrol (DES), on the activation of murine macrophages (RAW 264.7 cells) in vitro, particularly with regard to interferon (IFN)-gamma-induced nitric oxide (NO) production. (+/-)-IA inhibited NO production more strongly than DES as assessed by a nitrite assay. The inhibitory effect of (+/-)-IA on IFN-gamma-induced intracellular NO production was confirmed by direct staining of intracellular NO with diaminofluorescein-2 diacetyl. Inhibition of NO production was confirmed by Western blot analysis of IFN-gamma-induced NO synthase. Under IFN-gamma-stimulated conditions, the IFN-gamma activation site (GAS), which was the most important transcription factor, was significantly inhibited by (+/-)-IA. (+/-)-IA also promoted the activation of NF-kappaB. (+/-)-IA at 1 and 3 microM delayed the onset of apoptosis. Our results suggest that (+/-)-IA inhibited the activation of macrophages, resulting in the suppression of NO-mediated apoptosis. These results suggest a novel mechanism for the carcinogenic promoting activity of DES via its metabolite, (+/-)-IA.
Oda
Taiko
T
Department of Biochemistry, Kyoritsu College of Pharmacy, Tokyo, Japan. oda-ti@kyoritsu-ph.ac.jp
So
You
Y
Sato
Yoshihiro
Y
Shimizu
Noriaki
N
Handa
Hiroshi
H
Yasukochi
Yukio
Y
Kasahara
Tadashi
T
D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D004054:Diethylstilbestrol / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D004968:Estrogens, Non-Steroidal / Q000494:pharmacology; D007192:Indenes / Q000494:pharmacology*; D007371:Interferon-gamma / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D016328:NF-kappa B / Q000187:drug effects / Q000235:genetics; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000187:drug effects; D052247:Nitric Oxide Synthase Type II; D014158:Transcription, Genetic / Q000187:drug effects
D004968:Estrogens, Non-Steroidal; D007192:Indenes; D016328:NF-kappa B; D009569:Nitric Oxide; C047437:indenestrol; D004054:Diethylstilbestrol; D007371:Interferon-gamma; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse