Department of Veterinary Pharmacology, Graduate School of Agriculture and Life Sciences, University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
J Pharmacol Exp Ther. 2012 Mar;340(3):604-11. doi: 10.1124/jpet.111.189845. Epub 2011 Dec 2.
Intestinal subepithelial myofibroblasts (ISMFs) are mesenchymal cells that reside in the subepithelial region throughout the intestine. When the intestine is damaged, the migratory and mitotic responses of ISMFs are crucial for wound closure. However, their mechanism of action remains unknown. We have investigated the role of cyclooxygenase (COX) and its metabolite prostaglandin E(2) (PGE(2)) in the wound repair process of bovine ISMFs. The action of a mechanical scratch in a layer of ISMFs in cell culture elevated the levels of both COX-2 mRNA expression and PGE(2) secretion 1 and 6 h after the event. After 24 h ISMFs had migrated to and reduced the wounded area around the site of the scratch. Treatment with the COX-1/2 inhibitor indomethacin, the COX-2 inhibitor 3-(4-methylsulphonylphenyl)-4-phenyl-5-trifluoromethylisoxazole (CAY10404), or E prostanoid receptor 2 to 4 (EP2-EP4) antagonists significantly inhibited wound repair. Conversely, inhibition of wound closure by indomethicin was reversed by treatment with PGE(2) or agonists of the receptors EP2, EP3, or EP4 but not of EP1. Although EP2 to EP4 stimulation did not influence ISMF proliferation, it did stimulate ISMF migration in the transwell cell migration assay. It is noteworthy that cell migration stimulated by EP2 and EP4 was inhibited by the tyrosine kinase receptor inhibitor genistein and also by (Z)-3-[2,4-dimethyl-5-(2-oxo-1,2-dihydro-indol-3-ylidenemethyl)-1H-pyrrol-3-yl]-propionic acid (SU6668). However, cell migration stimulated by EP3 was unaffected. Reverse transcription-polymerase chain reaction showed EP2 or EP4 stimulation elevated the level of mRNA expression for fibroblast growth factor-2, which stimulates ISMF migration. Collectively, COX-2-dependent PGE(2) secretion promotes wound healing by ISMFs. PGE(2)-EP3 signaling may directly stimulate ISMF migration. PGE(2)-EP2/4 signaling indirectly stimulates ISMF migration by elevating the level of growth factor secretion.
肠黏膜下肌纤维母细胞（ISMFs）是位于整个肠道黏膜下层的间充质细胞。当肠道受损时，ISMFs 的迁移和有丝分裂反应对于伤口闭合至关重要。然而，其作用机制尚不清楚。我们研究了环氧化酶（COX）及其代谢产物前列腺素 E2（PGE2）在牛 ISMF 伤口修复过程中的作用。细胞培养中 ISMF 层的机械划痕作用会在事件发生后 1 小时和 6 小时分别升高 COX-2 mRNA 表达和 PGE2 分泌水平。24 小时后，ISMF 已迁移并减少划痕部位周围的受伤区域。用 COX-1/2 抑制剂吲哚美辛、COX-2 抑制剂 3-(4-甲基磺酰基苯基)-4-苯基-5-三氟甲基异恶唑（CAY10404）或 E 前列腺素受体 2 至 4（EP2-EP4）拮抗剂治疗可显著抑制伤口修复。相反，吲哚美辛抑制伤口闭合可被 PGE2 或受体 EP2、EP3 或 EP4 的激动剂逆转，但 EP1 的激动剂则不能。虽然 EP2 至 EP4 的刺激并不影响 ISMF 的增殖，但它确实刺激了 Transwell 细胞迁移测定中的 ISMF 迁移。值得注意的是，EP2 和 EP4 刺激引起的细胞迁移被酪氨酸激酶受体抑制剂金雀异黄素和（Z）-3-[2,4-二甲基-5-（2-氧代-1,2-二氢-吲哚-3-亚基甲基）-1H-吡咯-3-基]-丙酸（SU6668）抑制。然而，EP3 刺激的细胞迁移不受影响。逆转录-聚合酶链反应显示，EP2 或 EP4 的刺激会升高成纤维细胞生长因子-2 的 mRNA 表达水平，从而刺激 ISMF 的迁移。总的来说，COX-2 依赖性 PGE2 分泌通过 ISMF 促进伤口愈合。PGE2-EP3 信号可能直接刺激 ISMF 迁移。PGE2-EP2/4 信号通过升高生长因子分泌水平间接刺激 ISMF 迁移。
