Involvement of Nitric Oxide with Activation of CD14-TLR4-NF-kB Signaling in Mice with Dextran Sodium Sulfate-Induced Colitis

forming the corresponding non-electrophilic nitroalkane derivative. Notably, although 12-NO2-CLA is more rapidly metabolized than the 9-NO2 isomer, both are similarly potent at inducing Nrf2 activation and inhibiting the expression of NFNB-dependent products as demonstrated by western blot, reporter assays and RT-PCR analyses. These results indicate that NO 2-CLA formation and signaling are early events during inflammation. Finally, administration of either racemic NO2-CLA or CLA precursor during zymosan-induced peritonitis significantly attenuates inflammatory cell recruitment and decreases pro-inflammatory cytokine production. Taken together, our results demonstrate that CLA nitration during inflammatory responses results in the generation of the anti-inflammatory mediator NO2-CLA which has the potential to modulate local immune responses and promote injury resolution.

doi: xxxxx doi: 10.1016/j.freeradbiomed.2015.10.118 80 ,QYROYHPHQWRI1LWULF2[LGHZLWK$FWLYDWLRQRI&' 7/51)ț%6LJQDOLQJLQ0LFHZLWK'H[WUDQ6RGLXP 6XOIDWH,QGXFHG&ROLWLV

Keiji Yasukawa1, Xin Tun2, and Ken-ichi Yamada2 1 Daiichi University of Pharmacy, Japan, 2Kyushu University, Japan Ulcerative colitis is an inflammatory bowel disease characterized by bleeding of the colonic mucosa and ulceration. Nitric oxide (NO) production derived from inducible NO synthase via activation of nuclear factor kappa B (NF-ț% KDVEHHQUHSRUWHG,W is also reported that lipopolysaccharide (LPS)-induced stimulation of Toll-like receptor 4 (TLR4) mediated by CD14 can activate NFț% ,Q WKLV VWXG\ ZH LQYHVWLJDWHG WKH LQYROYHPHQW RI 12 production on activation of the CD14-TLR4-NF-ț% VLJQDOLQJ pathway in mice with DSS-induced colitis. Increased CD14 and TLR4 levels and nuclear translocation of NF-țB p65 by 5% DSS were suppressed by a NO scavenger, carboxy-PTIO. Conversely, a NO-releasing compound, NOC-18, increased CD14, TLR4 and NF-ț% S and exacerbated mucosal damage induced by DSS challenge. Both CD14 and nitrotyrosine were localized in the macrophage infiltrating into the colonic mucosa. RAW 264.7 was activated by LPS and NOC-18. Phosphorylated signal transducer and activator of transcription 3 (STAT3), CD14, NF-țB p65 and iNOS levels in the cell lysate were increased and those inflammation mediators were suppressed by TLR4 inhibitor peptide or NF-țB activation inhibitor. These data suggest that activation of CD14-TLR4-NF-ț% signaling induced by DSS might be associated with NO overproduction.

doi: xxxxx doi: 10.1016/j.freeradbiomed.2015.10.119

SFRBM 2015

S45