Project description:Foetal skin is known to heal without scar. This ability is lost in the third trimester of gestation. In mouse, scarless wound healing was reported until the day 15-16 of gestation. A range of factors that could explain the mechanisms of scarless skin wound healing have been identified, to mention reduced immune response, a greater proportion of collagen type III, hyaluronic acid and transforming growth factor beta isoform 3. The involvement of epigenetic changes, which are known to determine developmental processes, has not been examined in the context of scarless foetal skin healing so far. We performed the microarray analysis methylome and transcriptome of murine foetal dorsal skin at embryonic day 15 contrasted with those in later phases at embryonic days 18-19 as well as the in the adult mouse. The group of genes which show decreased methylation status in the foetal skin before the loss of ability to scarless healing between embryonic day 15 and 18 are enriched with transcriptional factors involved in embryonic morphogenesis, epithelium development, neuron differentiation, and synapse functions. The genes with increased methylation after the transition are associated with cell death and epithelial cell differentiation, inflammatory and wounding response and the degradation of hyaluronic acid. A substantial part of DNA methylation differences observed between embryonic day 15 and 18 were retained later at embryonic day 19 and in adults and remarkably correlated with gene expression changes. A major part of genes encoding the key factors responsible for cutaneous wound healing show significant changes in gene expression following the transition from scar free to normal healing. The results show that skin methylome and transcriptome undergoe extensive alterations following the loss of ability to scarless healing, while the functions associated with the changes imply their central role in skin wound repair.
Project description:Foetal skin is known to heal without scar. This ability is lost in the third trimester of gestation. In mouse, scarless wound healing was reported until the day 15-16 of gestation. A range of factors that could explain the mechanisms of scarless skin wound healing have been identified, to mention reduced immune response, a greater proportion of collagen type III, hyaluronic acid and transforming growth factor beta isoform 3. The involvement of epigenetic changes, which are known to determine developmental processes, has not been examined in the context of scarless foetal skin healing so far. We performed the microarray analysis methylome and transcriptome of murine foetal dorsal skin at embryonic day 15 contrasted with those in later phases at embryonic days 18-19 as well as the in the adult mouse. The group of genes which show decreased methylation status in the foetal skin before the loss of ability to scarless healing between embryonic day 15 and 18 are enriched with transcriptional factors involved in embryonic morphogenesis, epithelium development, neuron differentiation, and synapse functions. The genes with increased methylation after the transition are associated with cell death and epithelial cell differentiation, inflammatory and wounding response and the degradation of hyaluronic acid. A substantial part of DNA methylation differences observed between embryonic day 15 and 18 were retained later at embryonic day 19 and in adults and remarkably correlated with gene expression changes. A major part of genes encoding the key factors responsible for cutaneous wound healing show significant changes in gene expression following the transition from scar free to normal healing. The results show that skin methylome and transcriptome undergoe extensive alterations following the loss of ability to scarless healing, while the functions associated with the changes imply their central role in skin wound repair.
Project description:Proteins from human adult and foetal fibroblast cell lines were compared, focusing on those involved in wound healing. Proteins were separated through two-dimensional gel electrophoresis (2DE). Differences in protein spot intensity between the lineages were quantified through 3D gel scanning densitometry. Selected protein spots were excised, subjected to tryptic digests, prior to separation using HPLC with a linear ion trap mass spectrometer, and identified. Protein maps representing the proteomes from adult and foetal fibroblasts showed similar distributions but revealed differences in expression levels. Heat shock cognate 71 kDA protein, Tubulin alpha-1A chain, actin cytoplasmic-1, and neuron cytoplasmic protein were all expressed in significantly higher concentrations by foetal fibroblasts, nearly double those observed for their adult counterparts. Fructose bisphosphate aldolase A, Cofilin-1, Peroxiredoxin-1, Lactotransferrin Galectin-1, Profilin-1, and Calreticulin were expressed at comparatively higher concentrations by the adult fibroblasts. Significant differences in the expression levels of some proteins in human adult and foetal fibroblasts correlated with known differences in wound healing behaviour. This data may assist in the development of technologies to promote scarless wound healing and better functional tissue repair and regeneration.
Project description:Since the discovery of scarless fetal skin wound healing, research in the field has expanded significantly with the hopes of advancing the finding to adult human patients. There are several differences between fetal and adult skin that have been exploited to facilitate scarless healing in adults including growth factors, cytokines, and extracellular matrix substitutes. However, no one therapy, pathway, or cell subtype is sufficient to support scarless wound healing in adult skin. More recently, products that contain or mimic fetal and adult uninjured dermis were introduced to the wound healing market with promising clinical outcomes. Through our review of the major experimental targets of fetal wound healing, we hope to encourage research in areas that may have a significant clinical impact. Additionally, we will investigate therapies currently in clinical use and evaluate whether they represent a legitimate advance in regenerative medicine or a vulnerary agent. WIREs Dev Biol 2018, 7:e309. doi: 10.1002/wdev.309 This article is categorized under: Adult Stem Cells, Tissue Renewal, and Regeneration > Regeneration Plant Development > Cell Growth and Differentiation Adult Stem Cells, Tissue Renewal, and Regeneration > Environmental Control of Stem Cells.
Project description:Effective reprogramming of chronic wound healing remains challenging due to the limited drug delivery efficacy hindered by physiological barriers, as well as the inappropriate dosing timing in distinct healing stages. Herein, a core-shell structured microneedle array patch with programmed functions (PF-MNs) is designed to dynamically modulate the wound immune microenvironment according to the varied healing phases. Specifically, PF-MNs combat multidrug-resistant bacterial biofilm at the early stage via generating reactive oxygen species (ROS) under laser irradiation. Subsequently, the ROS-sensitive MN shell gradually degrades to expose the MN core component, which neutralizes various inflammatory factors and promotes the phase transition from inflammation to proliferation. In addition, the released verteporfin inhibits scar formation by blocking Engrailed-1 (En1) activation in fibroblasts. Our experiments demonstrate that PF-MNs promote scarless wound repair in mouse models of both acute and chronic wounds, and inhibit the formation of hypertrophic scar in rabbit ear models.
Project description:Wound healing is a well-organized dynamic process involving coordinated consecutive phases: homeostasis, inflammation, proliferation and resolution. Fibroblasts play major roles in skin wound healing such as in wound contraction and release of growth factors which are of importance in angiogenesis and tissue remodeling. Abnormal fibroblast phenotypes have been identified in patients with chronic wounds. In this work, we analyzed scRNA-seq datasets of normal and wounded skin from mice at day 4 post-wound to investigate fibroblast heterogeneity during the proliferative phase of wound healing. Compositional analysis revealed a specific subset of fibroblast (cluster 3) that primarily increased in wounded skin (14%) compared to normal skin (3.9%). This subset was characterized by a gene signature marked by the plasma membrane proteins Sfrp2 + Sfrp4 + Sfrp1 + and the transcription factors Ebf1 + Prrx1 + Maged1 + . Differential gene expression and enrichment analysis identified epithelial to mesenchymal transition (EMT) and angiogenesis to be upregulated in the emerging subset of fibroblasts of the wounded skin. Using two other datasets for murine wounded skin confirmed the increase in cluster 3-like fibroblasts at days 2, 7 and 14 post-wounding with a peak at day 7. By performing a similarity check between the differential gene expression profile between wounded and normal skin for this emerging fibroblast subset with drug signature from the ConnectivityMap database, we identified drugs capable of mimicking the observed gene expression change in fibroblasts during wound healing. TTNPB, verteprofin and nicotinic acid were identified as candidate drugs capable of inducing fibroblast gene expression profile necessary for wound healing. On the other hand, methocarbamol, ifosfamide and penbutolol were recognized to antagonize the identified fibroblast differential expression profile during wound healing which might cause delay in wound healing. Taken together, analysis of murine transcriptomic skin wound healing datasets suggested a subset of fibroblasts capable of inducing EMT and further inferred drugs that might be tested as potential candidates to induce wound closure.
Project description:In surgical and cosmetic studies, scarless regeneration is an ideal method to heal skin wounds. To study the technologies that enable scarless skin wound healing in medicine, animal models are useful. However, four-limbed vertebrates, including humans, generally lose their competency of scarless regeneration as they transit to their terrestrial life-stages through metamorphosis, hatching or birth. Therefore, animals that serve as a model for postnatal humans must be an exception to this rule, such as the newt. Here, we evaluated the adult newt in detail for the first time. Using a Japanese fire-bellied newt, Cynops pyrrhogaster, we excised the full-thickness skin at various locations on the body, and surveyed their re-epithelialization, granulation or dermal fibrosis, and recovery of texture and appendages as well as color (hue, tone and pattern) for more than two years. We found that the skin of adult newts eventually regenerated exceptionally well through unique processes of re-epithelialization and the absence of fibrotic scar formation, except for the dorsal-lateral to ventral skin whose unique color patterns never recovered. Color pattern is species-specific. Consequently, the adult C. pyrrhogaster provides an ideal model system for studies aimed at perfect skin wound healing and regeneration in postnatal humans.
Project description:In order to clarify the human response of re-epithelialization, we biopsied split-thickness skin graft donor site wounds immediately before and after harvesting, as well as during the healing process 3 and 7 days thereafter. Altogether 25 biopsies from 8 patients qualified for the study. All samples were analysed by genome-wide microarrays. Here we identified the genes associated with normal skin re-epithelialization on time-scale, and organized them by similarities according to their induction or suppression patterns during wound healing. Overall 25 samples were analyzed
Project description:In contrast to adult and late-gestation fetal skin wounds, which heal with scar, early-gestation fetal skin wounds display a remarkable capacity to heal scarlessly. Although the underlying mechanism of this transition from fetal-type scarless healing to adult-type healing with scar has been actively investigated for decades, in utero restoration of scarless healing in late-gestation fetal wounds has not been reported. In this study, using loss- and gain-of-function rodent fetal wound models, we identified that fibromodulin (Fm) is essential for fetal-type scarless wound healing. In particular, we found that loss of Fm can eliminate the ability of early-gestation fetal rodents to heal without scar. Meanwhile, administration of fibromodulin protein (FM) alone was capable of restoring scarless healing in late-gestation rat fetal wounds, which naturally heal with scar, as characterized by dermal appendage restoration and organized collagen architectures that were virtually indistinguishable from those in age-matched unwounded skin. High Fm levels correlated with decreased transforming growth factor (TGF)-β1 expression and scarless repair, while low Fm levels correlated with increased TGF-β1 expression and scar formation. This study represents the first successful in utero attempt to induce scarless repair in late-gestation fetal wounds by using a single protein, Fm, and highlights the crucial role that the FM-TGF-β1 nexus plays in fetal-type scarless skin repair.