Center for Gastrointestinal Biology and Diseases, Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina, United States of America.
PLoS One. 2012;7(3):e34172. doi: 10.1371/journal.pone.0034172. Epub 2012 Mar 27.
Nuclear factor of activated T cells (NFAT) plays a critical role in the development and function of immune and non-immune cells. Although NFAT is a central transcriptional regulator of T cell cytokines, its role in macrophage specific gene expression is less defined. Previous work from our group demonstrated that NFAT regulates Il12b gene expression in macrophages. Here, we further investigate NFAT function in murine macrophages and determined the effects of a cell permeable NFAT inhibitor peptide 11R-VIVIT on experimental colitis in mice. Treatment of bone marrow derived macrophages (BMDMs) with tacrolimus or 11R-VIVIT significantly inhibited LPS and LPS plus IFN-γ induced IL-12 p40 mRNA and protein expression. IL-12 p70 and IL-23 secretion were also decreased. NFAT nuclear translocation and binding to the IL-12 p40 promoter was reduced by NFAT inhibition. Experiments in BMDMs from IL-10 deficient (Il10(-/-)) mice demonstrate that inhibition of IL-12 expression by 11R-VIVIT was independent of IL-10 expression. To test its therapeutic potential, 11R-VIVIT was administered systemically to Il10(-/-) mice with piroxicam-induced colitis. 11R-VIVIT treated mice demonstrated significant improvement in colitis compared to mice treated with an inactive peptide. Moreover, decreased spontaneous secretion of IL-12 p40 and TNF in supernatants from colon explant cultures was demonstrated. In summary, NFAT, widely recognized for its role in T cell biology, also regulates important innate inflammatory pathways in macrophages. Selective blocking of NFAT via a cell permeable inhibitory peptide is a promising therapeutic strategy for the treatment of inflammatory bowel diseases.
活化 T 细胞核因子（NFAT）在免疫和非免疫细胞的发育和功能中发挥着关键作用。尽管 NFAT 是 T 细胞细胞因子的核心转录调节剂，但它在巨噬细胞特异性基因表达中的作用尚未确定。我们小组的先前工作表明，NFAT 调节巨噬细胞中 Il12b 基因的表达。在这里，我们进一步研究了 NFAT 在小鼠巨噬细胞中的功能，并确定了细胞通透 NFAT 抑制剂肽 11R-VIVIT 对小鼠实验性结肠炎的影响。他克莫司或 11R-VIVIT 处理骨髓来源的巨噬细胞（BMDMs）可显著抑制 LPS 和 LPS 加 IFN-γ诱导的 IL-12 p40 mRNA 和蛋白表达。IL-12 p70 和 IL-23 的分泌也减少。NFAT 抑制减少了 NFAT 核易位和与 IL-12 p40 启动子的结合。来自 IL-10 缺陷（Il10(-/-)）小鼠的 BMDM 实验表明，11R-VIVIT 抑制 IL-12 表达与 IL-10 表达无关。为了测试其治疗潜力，将 11R-VIVIT 全身给药给吡罗昔康诱导结肠炎的 Il10(-/-)小鼠。与用无活性肽治疗的小鼠相比，11R-VIVIT 治疗的小鼠的结肠炎有明显改善。此外，从结肠外植体培养物上清液中证明了 IL-12 p40 和 TNF 的自发分泌减少。总之，NFAT 因其在 T 细胞生物学中的作用而广为人知，它还调节巨噬细胞中重要的先天炎症途径。通过细胞通透抑制肽选择性阻断 NFAT 是治疗炎症性肠病的有前途的治疗策略。
