Department of Medicine, Stony Brook University, Stony Brook, New York, United States of America.
PLoS One. 2012;7(7):e41585. doi: 10.1371/journal.pone.0041585. Epub 2012 Jul 23.
Annexin A1 (ANXA1) inhibits NF-κB, a key regulator of inflammation, the common pathophysiological mechanism of inflammatory bowel diseases (IBD). MC-12, an ANXA1-based tripeptide, suppresses NF-κB activation. Here, we determined the efficacy of MC-12 in the control of IBD. Mice with colitis induced by dextran sodium sulfate (DSS) or 2,4,6-trinitro benzene sulfonic acid (TNBS) were treated with various doses of MC-12 administered intraperitoneally, orally or intrarectally. We determined colon length and the histological score of colitis, and assayed: in colon tissue the levels of TNF-α, IFN-γ, IL-1β, IL-6 and IL-10 by RT-PCR; prostaglandin E(2) (PGE(2)), cytoplasmic phospholipase A(2) (cPLA(2)) and myeloperoxidase by immunoassay; and COX-2 and NF- κB by immunohistochemistry; and in serum the levels of various cytokines by immunoassay. In both models MC-12: reversed dose-dependently colonic inflammation; inhibited by up to 47% myeloperoxidase activity; had a minimal effect on cytoplasmic phospholipase A(2); reduced significantly the induced levels of TNF-α, IFN-γ, IL-1β, IL-6 and IL-10, returning them to baseline. DSS and TNBS markedly activated NF-κB in colonic epithelial cells and MC-12 decreased this effect by 85.8% and 72.5%, respectively. MC-12 had a similar effect in cultured NCM460 normal colon epithelial cells. Finally, MC-12 suppressed the induction of COX-2 expression, the level of PGE(2) in the colon and PGE(2) metabolite in serum. In conclusion, MC-12, representing a novel class of short peptide inhibitors of NF-κB, has a strong effect against colitis in two preclinical models recapitulating features of human IBD. Its mechanism of action is complex and includes pronounced inhibition of NF-κB. MC-12 merits further development as an agent for the control of IBD.
膜联蛋白 A1（ANXA1）抑制核因子-κB（NF-κB），NF-κB 是炎症的关键调节因子，也是炎症性肠病（IBD）的常见病理生理机制。基于 ANXA1 的三肽 MC-12 可抑制 NF-κB 的激活。本研究旨在确定 MC-12 对 IBD 的控制作用。通过葡聚糖硫酸钠（DSS）或 2,4,6-三硝基苯磺酸（TNBS）诱导的小鼠结肠炎模型，采用不同剂量的 MC-12 经腹腔内、口服或直肠内给药进行治疗。我们测定了结肠长度和结肠炎的组织学评分，并通过 RT-PCR 测定了结肠组织中 TNF-α、IFN-γ、IL-1β、IL-6 和 IL-10 的水平；通过免疫测定法测定了前列腺素 E2（PGE2）、细胞质磷脂酶 A2（cPLA2）和髓过氧化物酶；通过免疫组化法测定了 COX-2 和 NF-κB；通过免疫测定法测定了血清中各种细胞因子的水平。在两种模型中，MC-12 均：以剂量依赖性方式逆转结肠炎症；抑制髓过氧化物酶活性高达 47%；对细胞质磷脂酶 A2 的影响最小；显著降低诱导的 TNF-α、IFN-γ、IL-1β、IL-6 和 IL-10 水平，使其恢复到基线水平。DSS 和 TNBS 可显著激活结肠上皮细胞中的 NF-κB，而 MC-12 可分别降低 85.8%和 72.5%的这种作用。MC-12 在培养的 NCM460 正常结肠上皮细胞中也有类似的作用。最后，MC-12 抑制了 COX-2 表达、结肠 PGE2 水平及其代谢产物在血清中的诱导。总之，MC-12 是一种新型的 NF-κB 短肽抑制剂，在两种模拟人类 IBD 特征的临床前模型中对结肠炎具有很强的作用。其作用机制复杂，包括对 NF-κB 的显著抑制。MC-12 有望进一步开发为控制 IBD 的药物。
