Reduction of nitric oxide synthase 2 expression by distamycin A improves survival from endotoxemia.
NO synthase 2 (NOS2) plays an important role in endotoxemia through overproduction of NO. Distamycin A (Dist A) belongs to a class of drugs termed minor-groove DNA binders, which can inhibit transcription factor binding to AT-rich regions of DNA. We and others have previously shown that AT-rich regions of DNA surrounding transcription factor binding sites in the NOS2 promoter are critical for NOS2 induction by inflammatory stimuli in vitro. Therefore, we hypothesized that Dist A would attenuate NOS2 up-regulation in vivo during endotoxemia and improve animal survival. C57BL/6 wild-type (WT) mice treated with Dist A and LPS (endotoxin) showed significantly improved survival compared with animals treated with LPS alone. In contrast, LPS-treated C57BL/6 NOS2-deficient (NOS2-/-) mice did not benefit from the protective effect of Dist A on mortality from endotoxemia. Treatment with Dist A resulted in protection from hypotension in LPS-treated WT mice, but not in NOS2-/- mice. Furthermore, LPS-induced NOS2 expression was attenuated in vivo (WT murine tissues) and in vitro (primary peritoneal and RAW 264.7 murine macrophages) with addition of Dist A. Dist A selectively decreased IFN regulatory factor-1 DNA binding in the enhancer region of the NOS2 promoter, and this IFN regulatory factor-1 site is critical for the effect of Dist A in attenuating LPS induction of NOS2. Our data point to a novel approach in modulating NOS2 expression in vivo during endotoxemia and suggest the potential for alternative treatment approaches for critical illness.
Baron
Rebecca M
RM
Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
Carvajal
Irvith M
IM
Liu
Xiaoli
X
Okabe
Rachel O
RO
Fredenburgh
Laura E
LE
Macias
Alvaro A
AA
Chen
Yen-Hsu
YH
Ejima
Kuniaki
K
Layne
Matthew D
MD
Perrella
Mark A
MA
D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000502:physiology; D004195:Disease Models, Animal; D004214:Distamycins / Q000494:pharmacology*; D019446:Endotoxemia / Q000201:enzymology / Q000235:genetics / Q000401:mortality* / Q000517:prevention & control*; D004790:Enzyme Induction / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000276:immunology; D007022:Hypotension / Q000201:enzymology / Q000235:genetics / Q000517:prevention & control; D050856:Interferon Regulatory Factor-1; D007371:Interferon-gamma / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000037:antagonists & inhibitors / Q000633:toxicity; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000201:enzymology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors* / Q000096:biosynthesis* / Q000172:deficiency / Q000235:genetics; D052247:Nitric Oxide Synthase Type II; D010750:Phosphoproteins / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000502:physiology; D011401:Promoter Regions, Genetic / Q000187:drug effects; D011485:Protein Binding / Q000187:drug effects / Q000235:genetics
D004268:DNA-Binding Proteins; D004214:Distamycins; D004791:Enzyme Inhibitors; D050856:Interferon Regulatory Factor-1; C494258:Irf1 protein, mouse; D008070:Lipopolysaccharides; D010750:Phosphoproteins; C030000:stallimycin; D007371:Interferon-gamma; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse