Department of Pathology, University of Michigan, Ann Arbor, Michigan, USA.
Institute of Natural Medicine, University of Toyama, Toyama, Japan.
JCI Insight. 2022 Dec 8;7(23):e162392. doi: 10.1172/jci.insight.162392.
Acute and chronic intestinal inflammation is associated with epithelial damage, resulting in mucosal wounds in the forms of erosions and ulcers in the intestinal tract. Intestinal epithelial cells (IECs) and immune cells in the wound milieu secrete cytokines and lipid mediators to influence repair. Leukotriene B4 (LTB4), a lipid chemokine, binds to its receptor BLT1 and promotes migration of immune cells to sites of active inflammation; however, a role for intestinal epithelial BLT1 during mucosal wound repair is not known. Here we report that BLT1 was expressed in IECs both in vitro and in vivo, where it functioned as a receptor not only for LTB4 but also for another ligand, resolvin E1. Intestinal epithelial BLT1 expression was increased when epithelial cells were exposed to an inflammatory microenvironment. Using human and murine primary colonic epithelial cells, we reveal that the LTB4/BLT1 pathway promoted epithelial migration and proliferation leading to accelerated epithelial wound repair. Furthermore, in vivo intestinal wound repair experiments in BLT1-deficient mice and bone marrow chimeras demonstrated an important contribution of epithelial BLT1 during colonic mucosal wound repair. Taken together, our findings show a potentially novel prorepair in IEC mechanism mediated by BLT1 signaling.
急性和慢性肠道炎症与上皮损伤有关,导致肠道出现糜烂和溃疡等黏膜伤口。伤口微环境中的肠上皮细胞(IECs)和免疫细胞会分泌细胞因子和脂质介质来影响修复。白三烯 B4(LTB4)是一种脂质趋化因子,与受体 BLT1 结合,促进免疫细胞向活跃炎症部位迁移;然而,肠道上皮细胞 BLT1 在黏膜伤口修复中的作用尚不清楚。在这里,我们报告说 BLT1 在体外和体内的 IEC 中表达,它不仅是 LTB4 的受体,也是另一种配体,即 resolvin E1 的受体。当上皮细胞暴露于炎症微环境时,肠上皮 BLT1 的表达增加。使用人源和鼠源原代结肠上皮细胞,我们揭示 LTB4/BLT1 通路促进上皮细胞迁移和增殖,从而加速上皮细胞伤口修复。此外,BLT1 缺陷小鼠和骨髓嵌合体的体内肠道伤口修复实验表明,BLT1 在结肠黏膜伤口修复过程中发挥了重要作用。总之,我们的研究结果表明,BLT1 信号介导了一种潜在的新型 IEC 促修复机制。