Macrophage-derived IL-10 mediates mucosal repair by epithelial WISP-1 signaling
Miguel Quiros, … , Timothy L. Denning, Asma Nusrat
Miguel Quiros, … , Timothy L. Denning, Asma Nusrat
Published August 7, 2017
Citation Information: J Clin Invest. 2017;127(9):3510-3520. https://doi.org/10.1172/JCI90229.
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Research Article Immunology Inflammation

Macrophage-derived IL-10 mediates mucosal repair by epithelial WISP-1 signaling

Abstract

In response to injury, epithelial cells migrate and proliferate to cover denuded mucosal surfaces and repair the barrier defect. This process is orchestrated by dynamic crosstalk between immune cells and the epithelium; however, the mechanisms involved remain incompletely understood. Here, we report that IL-10 was rapidly induced following intestinal mucosal injury and was required for optimal intestinal mucosal wound closure. Conditional deletion of IL-10 specifically in CD11c-expressing cells in vivo implicated macrophages as a critical innate immune contributor to IL-10–induced wound closure. Consistent with these findings, wound closure in T cell– and B cell–deficient Rag1–/– mice was unimpaired, demonstrating that adaptive immune cells are not absolutely required for this process. Further, following mucosal injury, macrophage-derived IL-10 resulted in epithelial cAMP response element–binding protein (CREB) activation and subsequent synthesis and secretion of the pro-repair WNT1-inducible signaling protein 1 (WISP-1). WISP-1 induced epithelial cell proliferation and wound closure by activating epithelial pro-proliferative pathways. These findings define the involvement of macrophages in regulating an IL-10/CREB/WISP-1 signaling axis, with broad implications in linking innate immune activation to mucosal wound repair.

Authors

Miguel Quiros, Hikaru Nishio, Philipp A. Neumann, Dorothee Siuda, Jennifer C. Brazil, Veronica Azcutia, Roland Hilgarth, Monique N. O’Leary, Vicky Garcia-Hernandez, Giovanna Leoni, Mingli Feng, Gabriela Bernal, Holly Williams, Priya H. Dedhia, Christian Gerner-Smidt, Jason Spence, Charles A. Parkos, Timothy L. Denning, Asma Nusrat

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Figure 1

IL-10 is synthesized and released as a response to intestinal mucosal injury.

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IL-10 is synthesized and released as a response to intestinal mucosal in...
(A) Scratch wound-healing assay using IEC monolayers. rhIL-10 was added to wounded IECs, and wound widths were determined 0, 12, and 24 hours after injury (**P < 0.01 and ***P < 0.001, n = 5, mean ± SEM). (B) IEC expression of IL-10Rα was analyzed by qPCR and Western blotting. (C) Scratch wound-healing assay in IEC monolayers. Cells were transfected or not transfected with either a scramble siRNA or IL-10Rα siRNA, and wound widths were determined 0 and 24 hours after wounding (***P < 0.001, n = 5, mean ± SEM). Colonoscopy-based biopsy wounds (2-mm punch biopsies) were generated in C57BL/6 mice and collected on days 1–3 after injury. Intact tissue was used as a control. These samples were analyzed by qPCR for IL-10 kinetics in intestinal mucosal wounds (D), ELISA (E), and Western blotting (F). (D) Il10 qPCR of intact and wounded tissue on different post-injury days (*P < 0.05 and ***P < 0.001; n = 3, mean ± SEM). (E) Punch biopsy samples (2-mm) of resealing colonic wounds on different post-injury days and intact tissue were incubated overnight in complete DMEM. Supernatants were collected, and IL-10 secretion was analyzed by ELISA. (***P < 0.001; n = 3, mean ± SEM). (F) Lysates from wounded tissue on different post-injury days and intact tissue were immunoblotted for IL-10 (representative blot is shown, n = 3). Statistical comparisons were performed using ANOVA with Tukey’s multiple comparisons post test and a 2-tailed Student’s t test. IT, intact tissue; NT, nontransfected; Scr, scramble.