Critical role of thrombospondin-1 in promoting intestinal mucosal wound repair
Zachary S. Wilson, … , Asma Nusrat, Charles A. Parkos
Zachary S. Wilson, … , Asma Nusrat, Charles A. Parkos
Published July 30, 2024
Citation Information: JCI Insight. 2024;9(17):e180608. https://doi.org/10.1172/jci.insight.180608.
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Research Article Gastroenterology Inflammation

Critical role of thrombospondin-1 in promoting intestinal mucosal wound repair

Abstract

Thrombospondin-1 (TSP1) is a matricellular protein associated with the regulation of cell migration through direct binding interactions with integrin proteins and by associating with other receptors known to regulate integrin function, including CD47 and CD36. We previously demonstrated that deletion of an epithelial TSP1 receptor, CD47, attenuates epithelial wound repair following intestinal mucosal injury. However, the mechanisms by which TSP1 contributes to intestinal mucosal repair remain poorly understood. Our results show upregulated TSP1 expression in colonic mucosal wounds and impaired intestinal mucosal wound healing in vivo upon intestinal epithelium–specific loss of TSP1 (VillinCre/+ Thbs1fl/fl or Thbs1ΔIEC mice). We report that exposure to exogenous TSP1 enhanced migration of intestinal epithelial cells in a CD47- and TGF-β1–dependent manner and that deficiency of TSP1 in primary murine colonic epithelial cells resulted in impaired wound healing. Mechanistically, TSP1 modulated epithelial actin cytoskeletal dynamics through suppression of RhoA activity, activation of Rho family small GTPase (Rac1), and changes in filamentous-actin bundling. Overall, TSP1 was found to regulate intestinal mucosal wound healing via CD47 and TGF-β1, coordinate integrin-containing cell–matrix adhesion dynamics, and remodel the actin cytoskeleton in migrating epithelial cells to enhance cell motility and promote wound repair.

Authors

Zachary S. Wilson, Arturo Raya-Sandino, Jael Miranda, Shuling Fan, Jennifer C. Brazil, Miguel Quiros, Vicky Garcia-Hernandez, Qingyang Liu, Chang H. Kim, Kurt D. Hankenson, Asma Nusrat, Charles A. Parkos

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Figure 7

Deficiency in TSP1 impairs epithelial repair and cytoskeletal rearrangement.

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Deficiency in TSP1 impairs epithelial repair and cytoskeletal rearrangem...
(A) Wound closure rates at 20 hours after wounding in a scratch wound assay of WT and Thbs1–/– murine IECs (n = 8, N = 3 independent experiments). Performed unpaired, 2-tailed Student’s t test. (B) Wound closure rates at 24 hours after wounding in a scratch wound assay of Thbs1–/– murine IECs in response to TSP1 (n = 13, N = 3 independent experiments). Performed Kruskal-Wallis 1-way ANOVA with Dunn’s multiple comparisons test. (C) Immunofluorescence of phosphorylated p130Cas Y410 and actin in WT and Thbs1–/– murine IECs in response to 24-hour treatment with TSP1 (representative of N = 3 experiments). Scale bar = 50 μm, 20 μm for inset. Performed 1-way ANOVA with Tukey’s multiple-comparison test. (D) Immunofluorescence of pMLC S19 and actin in WT and Thbs1–/– murine IECs in response to 24-hour treatment with TSP1 (representative of N = 3 experiments). Scale bar = 20 μm. Quantification of immunofluorescence below. Performed 1-way ANOVA with Tukey’s multiple-comparison test. Box plots show interquartile range, median (line), and minimum and maximum (whiskers). *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001.