Snail family proteins regulate transcription of molecules for cell–cell adhesion during epithelial–mesenchymal transition (EMT). Based on putative glycogen synthase kinase 3β (GSK‐3β) phosphorylation sites within the Slug/Snail2, we explored the significance of GSK‐3β‐mediated phosphorylation in Slug/Snail2 expression during EMT. Mutation of the putative GSK‐3β phosphorylation sites (S92/96A or S100/104A) enhanced the Slug/Snail2‐mediated EMT properties of E‐cadherin repression and vimentin induction, compared with wild‐type Slug/Snail2. S92/96A mutation inhibited degradation of Slug/Snail2 and S100/104A mutation extended nuclear stabilization. Inhibition of GSK‐3β activity caused similar effects, as did the phosphorylation mutations. Thus, our study suggests that GSK‐3β‐mediated phosphorylation of Slug/Snail2 controls its turnover and localization during EMT.
Beta-glucans, which existed in the cell walls of cereals, bacteria, and fungi, comprise a group of β-d-glucose polysaccharides. We investigated the effects of four kinds of beta-glucan, that are derived from barley, yeast, mushroom, and euglena on wound healing. The migration and viability of keratinocyte or fibroblast were analyzed using the in vitro scratch wound healing assay, invasion assay, MTT assay, and in vivo assay. All the beta-glucans had a significant effect on keratinocyte migration at 20 μM and showed no toxicity on dermal fibroblast. Moreover, treatment of keratinocytes with the beta-glucan derived from the mushroom (Schizophyllum commune) promoted in vivo wound closure. The Integrin/FAK/Src pathway is known to affect cell migration by forming lamellipodia. Beta-glucan from S. commune activates the Integrin/FAK/Src signaling pathway in a time-dependent. Reactive oxygen species are associated with fibroblast differentiation to contract dermal layer and synthesize collagens. We found that fibroblast was activated by increasing NOX4 expression. We propose that beta-glucan derived from mushroom is capable of promoting keratinocyte migration via the induction of FAK/Src phosphorylation there by accelerating wound closure and activating dermal fibroblast differentiation through NADPH oxidase for matrix remodeling.
7 November 2012 in Immunopharmacology and Immunotoxicology
The aerial parts of Artemisia capillaris (Compositae) have been used in traditional Korean medicine as a cholagogic, antipyretic, anti-inflammatory, and diuretic purposes. In our previous study, et...
Objective: Recognized as pathogen-associated molecular patterns (PAMPs), β-glucans, a naturally occurring heterogeneous group of polysaccharides, were investigated for their ability to accelerate wound healing in the form of high water-retaining hydrogel dressing. Approach: Full-thickness wounds on the dorsal side of mice created using a 5-mm biopsy punch were treated with β-glucan-based hydrogel for 2 weeks. Standardized photographs of the wound site were taken at regular time intervals to calculate the percentage of wound closure. Tissues isolated from the wound area were subjected to histological examination and immunoblot analysis. Results: β-Glucan-based hydrogel significantly accelerated the duration of wound healing and enhanced the development of skin appendages in the regenerated skin tissue. Increased expression of transforming growth factor-β3 in the skin tissue isolated from the healed wound site indicated that skin regeneration rather than skin repair occurred, thereby minimizing cutaneous scarring. The expression level of cytokeratin 10 and cytokeratin 14 in the isolated skin tissue revealed that the wounds treated with hydrogel showed proper differentiation and proliferation of keratinocytes in the epidermal layer. Innovation: Immunomodulating β-glucan (responsible for fighting infections at the wound site, and enhancing the migration and proliferation of keratinocytes and fibroblasts) in the form of a three-dimensional hydrogel membrane that retains a high water content (responsible for cooling and soothing effect around the wound site, thereby reducing pain) was prepared and analyzed for its effects on the cutaneous wound healing mechanism. Conclusion: β-Glucan-based hydrogels are promising as wet wound dressings in the health care industry.
Keratinocyte-fibroblast interactions are critical for skin repair after injury. During the proliferative phase of wound healing, proliferation, migration and differentiation of these cells are the major mechanisms leading to tissue remodeling. We have previously reported that glycitin, a major soy isoflavone, stimulates dermal fibroblast proliferation; and the phytochemical, 4′,6,7-trimethoxyisoflavone (TMF), induces migration of HaCaT keratinocyte cells. We therefore investigated whether these compounds display synergistic effects on skin cells during wound healing in vitro and in vivo. Co-treatment with TMF and glycitin synergistically promotes the proliferation and migration of both keratinocytes and dermal fibroblasts, with a 1:1 ratio of these compounds showing the greatest efficacy in our co-culture system. This keratinocyte-fibroblast interaction occurred via the secretion of TGF-β, and the induction of differentiation and proliferation was confirmed in both indirect and direct co-culture assays. In an excisional and burn wound animal model, mice treated with a 1:1 ratio of TMF and glycitin showed faster wound closure, regeneration and scar reduction than even the positive control drug. These data indicate that two isoflavones, TMF and glycitin, act synergistically to promote wound healing and anti-scarring and could potentially be developed together as a bioactive therapeutic for wound treatment.