GRHL3 activates FSCN1 to relax cell-cell adhesions between migrating keratinocytes during wound reepithelialization
Ghaidaa Kashgari, … , Ping H. Wang, Bogi Andersen
Ghaidaa Kashgari, … , Ping H. Wang, Bogi Andersen
Published September 8, 2021
Citation Information: JCI Insight. 2021;6(17):e142577. https://doi.org/10.1172/jci.insight.142577.
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Research Article Dermatology Genetics

GRHL3 activates FSCN1 to relax cell-cell adhesions between migrating keratinocytes during wound reepithelialization

Abstract

The migrating keratinocyte wound front is required for skin wound closure. Despite significant advances in wound healing research, we do not fully understand the molecular mechanisms that orchestrate collective keratinocyte migration. Here, we show that, in the wound front, the epidermal transcription factor Grainyhead like-3 (GRHL3) mediates decreased expression of the adherens junction protein E-cadherin; this results in relaxed adhesions between suprabasal keratinocytes, thus promoting collective cell migration and wound closure. Wound fronts from mice lacking GRHL3 in epithelial cells (Grhl3-cKO) have lower expression of Fascin-1 (FSCN1), a known negative regulator of E-cadherin. Assay for Transposase-Accessible Chromatin using sequencing (ATAC-seq) on wounded keratinocytes shows decreased wound-induced chromatin accessibility near the Fscn1 gene in Grhl3-cKO mice, a region enriched for GRHL3 motifs. These data reveal a wound-induced GRHL3/FSCN1/E-cadherin pathway that regulates keratinocyte-keratinocyte adhesion during wound-front migration; this pathway is activated in acute human wounds and is altered in diabetic wounds in mice, suggesting translational relevance.

Authors

Ghaidaa Kashgari, Sanan Venkatesh, Samuel Refuerzo, Brandon Pham, Anita Bayat, Rachel Herndon Klein, Raul Ramos, Albert Paul Ta, Maksim V. Plikus, Ping H. Wang, Bogi Andersen

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Figure 2

GRHL3 is required for proper architecture and function of the collectively migrating wound front.

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GRHL3 is required for proper architecture and function of the collective...
(A) Schematic representation of the full-thickness mouse wound model for healing studies. (B) Macroscopic images of full-thickness wounds at the indicated times after wounding in WT and Grhl3-cKO mice. (C) Wound size over time in WT and Grhl3-cKO mice (n = 5/genotype). (D) H&E staining of wound sections 5 days after wounding in WT and Grhl3-cKO mice. Dashed lines indicate the basal wound epithelium. Scale bar: 65 μm. (E) The length of the migrating epithelial wound front 3 and 5 days after wounding in WT and Grhl3-cKO mice (n = 3–5/genotype). (F) The thickness of the migrating epithelial wound front 5 days after wounding in WT and Grhl3-cKO mice (n = 3–5/genotype). (G) IHC staining with anti-BrdU antibody in wound sections 5 days after wounding in WT and Grhl3-cKO mice. Right panels show higher magnifications of the wounded epidermis. Dashed lines indicate the basal epithelium. Scale bar: 33 μm. Black arrows indicate BrdU+ cells. (H) Percentage of BrdU+ cells in the wound-front epidermis at days 3 and 5 after wounding in WT and Grhl3-cKO mice (n = 3–5/genotype). (I) Masson’s trichrome staining of wound sections 10 days after wounding in WT and Grhl3-cKO mice. Scale bar: 80 μm. (K) Percentage of measured collagen index in the wound bed 10 days after wounding in WT and Grhl3-cKO mice (n = 3/genotype). (J) Higher magnification images of Masson’s trichrome staining in day 10 wound sections. Note the attachment of a scab to the wounded epidermis in Grhl3-cKO mice. Scale bar: 40 μm. Statistical significance was determined using 1-way ANOVA (C, E, and H) and Student’s t test (F and K). Data are presented as mean ± SEM.