Project description:Cold atmospheric plasma jet (CAPJ) is composed of a variety of reactive species and has been demonstrated to have an effect on promoting wound healing. However, not all served-subjects respond equally to CAPJ, and indeed the underlying cellular mechanisms are rarely understood. Proteomics results clearly revealed that wound repair in keratinocytes was accelerated by plasma-activated medium (PAM) treatment through phosphorylating CK2-coordinated PI3K/AKT and MAPK signaling pathways, activating their downstream physiological responses for cell migration, proliferation and extracellular vesicles mediated cell-cell communication. Moreover, CAPJ-treated wound tissues showed a denser and well-organized extracellular matrix (ECM) architecture, implying the speed-up of epithelialization in wound healing. This study unveiled the primary cellular responses affected by CAPJ during wound
repair, providing valuable insights for the treatment selection and the development of therapeutic strategies to achieve better therapy outcomes.
Project description:While considerable progress has been made towards understanding the complex processes and pathways that regulate human wound healing, regenerative medicine has been unable to develop therapies that coax the natural wound environment to heal scar-free. The inability to induce perfect skin regeneration stems partly from our limited understanding of how scar-free healing occurs in a natural setting. Here we have investigated the wound repair process in adult axolotls and demonstrate that they are capable of perfectly repairing full thickness excisional wounds made on the flank. In the context of mammalian wound repair, our findings reveal a substantial reduction in hemostasis, reduced neutrophil infiltration and a relatively long delay in production of new extracellular matrix (ECM) during scar-free healing. Additionally, we test the hypothesis that metamorphosis leads to scarring and instead show that terrestrial axolotls also heal scar-free, albeit at a slower rate. Analysis of newly forming dermal ECM suggests that low levels of fibronectin and high levels of tenascin-C promote regeneration in lieu of scarring. Lastly, a genetic analysis during wound healing comparing epidermis between aquatic and terrestrial axolotls suggests that matrix metalloproteinases may regulate the fibrotic response. Our findings outline a blueprint to understand the cellular and molecular mechanisms coordinating scar-free healing that will be useful towards elucidating new regenerative therapies targeting fibrosis and wound repair. We used microarray analysis to determine the gene expression changes that take place during scar free wound healing in aquatic and terrestrial axolotl salamanders. Epidermal tissue was harvested using a 4mm biopsy punch. Two wounds were made along the flank and posterior to the forelimbs. Harvested epidermis was pooled for each animal. Four biological replicates were collected from uninjured epidermis (D0) and at 1, 3, and 7 days post injury.
Project description:Impaired healing of diabetic wounds causes significant morbidity and mortality. This study aimed to identify novel mechanisms of diabetic wound healing defects and test a therapeutic intervention using diabetic mouse and pig models. We found Smad7 transgene expression in mouse epidermis promoting wound healing in diabetic dbdb mice, with reductions in obesity and blood glucose. To isolate effects of Smad7 on wounds, we created a Smad7-based biologic (Tat-PYC-Smad7) that penetrates wound cells. Topical application of Tat-PYC-Smad7 to diabetic pig and mouse wounds accelerated healing compared to controls. RNAseq analysis of mouse wound samples showed reduced TGF/NFB signaling, leading to faster re-epithelialization and better extracellular matrix remodeling. Tat-PYC-Smad7 also attenuated neutrophil degranulation and NETosis by blocking histone 3 citrullination and inhibiting myeloperoxidase activities. Our study reveals that Tat-PYC-Smad7 promotes diabetic wound healing by targeting keratinocytes and neutrophils, providing insight into cellular mechanisms of diabetic wound healing defects targetable by Smad7-based therapy.
Project description:Repairing a damaged body part is critical for the survival of an organism. Tissue damage induces rapid responses to activate downstream events including defense, regeneration and wound healing. Despite accumulating knowledge of early wound signaling including the orchestrated actions of phytohormones, electric circus and reactive oxygen species, our knowledge about the end point of a wound response - wound healing, is still limited. We observed that a local temperature reduction associated with the activation of cold-responsive genes occurred at wounding site on Arabidopsis leaves, which was likely caused by evaporative cooling. The disappearance of localized cooling and restoration of cold responsive genes to a steady state could be used as a quantitative readout of wound healing. Based on these observations, we developed a deep learning pipeline to monitor the dynamics of wound healing. We found that CBFs transcription factors relay injury-induced cooling signal to wound healing. Thus, our work provides a tool to quantify wound healing in plants and advances our understanding of tissue repair in plants.
Project description:To develop effective therapeutic interventions that prevent scar formation and encourage regeneration of healthy skin, we need to better understand the cellular and molecular process that are engaged during the wound healing process in humans. However, our cellular and molecular understanding of how humans heal deep dermal wounds remains limited. Our recent work using different animal models of skin wound healing has identified the acute wound healing immune response as a key determinant of terminal fibrotic outcomes. Here, our goal is to compare the immune response during human wound healing to datasets we have generated from large animal models that are capable of scarless healing, in order to determine how to most appropriately modify the process in humans to improve outcomes (and mitigate scar).
Project description:While considerable progress has been made towards understanding the complex processes and pathways that regulate human wound healing, regenerative medicine has been unable to develop therapies that coax the natural wound environment to heal scar-free. The inability to induce perfect skin regeneration stems partly from our limited understanding of how scar-free healing occurs in a natural setting. Here we have investigated the wound repair process in adult axolotls and demonstrate that they are capable of perfectly repairing full thickness excisional wounds made on the flank. In the context of mammalian wound repair, our findings reveal a substantial reduction in hemostasis, reduced neutrophil infiltration and a relatively long delay in production of new extracellular matrix (ECM) during scar-free healing. Additionally, we test the hypothesis that metamorphosis leads to scarring and instead show that terrestrial axolotls also heal scar-free, albeit at a slower rate. Analysis of newly forming dermal ECM suggests that low levels of fibronectin and high levels of tenascin-C promote regeneration in lieu of scarring. Lastly, a genetic analysis during wound healing comparing epidermis between aquatic and terrestrial axolotls suggests that matrix metalloproteinases may regulate the fibrotic response. Our findings outline a blueprint to understand the cellular and molecular mechanisms coordinating scar-free healing that will be useful towards elucidating new regenerative therapies targeting fibrosis and wound repair.
Project description:Negative-pressure wound therapy (NPWT) is widely used to improve skin wound healing and to accelerate wound bed preparation. Although NPWT has been extensively studied as a treatment for deep wounds, its effect on epithelialization of superficial dermal wounds remains unclear. To clarify the effect of NPWT on reepithelialization, we applied NPWT on split- thickness skin graft donor sites from the first postoperative day (POD) to the seventh POD. Six patients took part in the study and two samples were obtained from each. The first biopsy sample was taken at elective surgery before split-thickness skin grafting and the second one during reepithelialization on the seventh POD. In all 12 samples (eight from four NPWT patients, and four from two control patients) were collected for this study. From each sample, we carried out a comprehensive genome-wide microarray analysis. Data from patients receiving NPWT were compared groupwise with data from those not receiving NPWT. Overall 12 samples were analyzed
Project description:Effective therapy of wounds is difficult, especially for chronic, non-healing wounds, and novel therapeutics are urgently needed. This challenge can be addressed with bioactive wound dressings providing a microenvironment and facilitating cell proliferation and migration, ideally incorporating actives which initiate and/or progress effective healing upon release. In this context, electrospun scaffolds loaded with growth factors emerged as promising wound dressings due to their biocompatibility, similarity to the extracellular matrix and potential for controlled drug release. In this study, electrospun core-shell fibers were designed composed of a combination of polycaprolactone and polyethylene oxide. Insulin, a proteohormon with growth factor characteristics, was successfully incorporated into the core and was released in a controlled manner. The fibers exhibited favorable mechanical properties and a surface guiding cell migration for wound closure in combination with a high uptake capacity for wound exudate. Biocompatibility and significant wound healing effects were shown in interaction studies with human skin cells. As a new approach, analysis of the wound proteome in treated ex vivo human skin wounds clearly demonstrated a remarkable increase in wound healing biomarkers. Based on these findings, insulin-loaded electrospun wound dressings bear a high potential as effective wound healing therapeutics overcoming current challenges in the clinics.