Project description:Study the effect of novel octapeptide isolated from Lingzhi mushroom on skin melanocyte cell (Mus Musculus) by gel-free based proteomics
Project description:Mice were wounded and skin samples of the scar collected on the day of wound closure. We compared Mixed mice (B6/FVB/SJL), a strain of high regeneration, versus C57bl mice, a strain of low regeneration. Whole skin biopsies of wound scars were submitted for Affymetrix Exon arrays. 4 mice each of 2 distinct strains of differing regeneration levels were collected.
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:We compared gene expression differences in the polytypic species complex Mus musculus (Mus musculus musculus, Mus musculus domesticus, Mus musculus castaneus and Mus musculus ssp) with that of Mus spretus via oligonucleotide microarrays representing more than 20,000 genes. Analysis of the results by two way ANOVA statistics suggests that the most genes with significant differences in expression levels among the subspecies are found in liver and kidney and the least in testis. This picture is different when one compares with Mus spretus, where the largest number of differences is found in testis. Keywords: multi-species comparison
Project description:Macrophages play an essential role in tissue regeneration. However, the ability to dissect the role of macrophages in regeneration from their role in wound healing with scar has been hampered by a lack of comparative systems. In this study, we use a mammalian model of tissue regeneration and scar formation to contrast the role of macrophages in both wound healing paradigms. The African Spiny mouse (A. cahirinus) can regenerate tissue of the external ear pinnae after 4mm biopsy punch. The common lab mouse (M. musculus) forms a scar after the same injury. We test the potential of bone marrow derived macrophages from both species to activate local ear fibroblasts and find macrophages from A. cahirinus are able to induce a matrix turnover phenotype in fibroblasts from both species. We identify growth factors and cytokines specific to macrophages derived from A. cahirinus, and using single cell RNAseq and screening with these factors, we identify populations of macrophages unique to a regenerating injury compared to scar forming injury. Finally we test how macrophage populations change over time in a regenerating injury and how they differ from each stage in a scar forming system
Project description:Macrophages play an essential role in tissue regeneration. However, the ability to dissect the role of macrophages in regeneration from their role in wound healing with scar has been hampered by a lack of comparative systems. In this study, we use a mammalian model of tissue regeneration and scar formation to contrast the role of macrophages in both wound healing paradigms. The African Spiny mouse (A. cahirinus) can regenerate tissue of the external ear pinnae after 4mm biopsy punch. The common lab mouse (M. musculus) forms a scar after the same injury. We test the potential of bone marrow derived macrophages from both species to activate local ear fibroblasts and find macrophages from A. cahirinus are able to induce a matrix turnover phenotype in fibroblasts from both species. We identify growth factors and cytokines specific to macrophages derived from A. cahirinus, and using single cell RNAseq and screening with these factors, we identify populations of macrophages unique to a regenerating injury compared to scar forming injury. Finally we test how macrophage populations change over time in a regenerating injury and how they differ from each stage in a scar forming system
Project description:Mammalian skin wounds heal by forming fibrotic scars. We report that reindeer antler velvet exhibits regenerative wound healing, whereas identical injury to back skin forms scar. This regenerative capacity was retained following ectopic transplantation of velvet to scar-forming sites. Single-cell mRNA/ATAC-Sequencing revealed that while uninjured velvet fibroblasts resembled human fetal fibroblasts, back skin fibroblasts were enriched in pro-inflammatory features resembling adult human fibroblasts. Injury elicited site-specific immune polarization; back skin fibroblasts amplified the immune response, whereas velvet fibroblasts adopted an immunosuppressive state leading to restrained myeloid maturation and hastened immune resolution ultimately enabling myofibroblast reversion to a regeneration-competent state. Finally, regeneration was blunted following application of back skin associated immunostimulatory signals or inhibition of pro-regenerative factors secreted exclusive to velvet fibroblasts. This study highlights a unique model to interrogate mechanisms underlying divergent healing outcomes and nominates both decoupling of stromal-immune crosstalk and reinforcement of pro-regenerative fibroblast programs to mitigate scar.
Project description:Mice were wounded and skin samples of the scar collected on the day of wound closure. We compared Mixed mice (B6/FVB/SJL), a strain of high regeneration, versus C57bl mice, a strain of low regeneration.