Project description:Keloids are scars that extend beyond original wounds and are resistant to treatment. In order to improve understanding of the molecular basis of keloid scarring, we have assessed the genomic profiles of keloid fibroblasts and keratinocytes. Skin and scar tissues were obtained for isolation of primary keratinocytes and fibroblasts. Keloid scars were excised from patients undergoing scar excision surgery, normal skin samples were isolated from patients undergoing elective plastic surgery. Primary culters were prepared for keratinocytes and fibroblasts, and were harvested for analysis up to passage three. Nine keloid scars, for adjacent non-lesional keloid skin samples, and three normal skin samples were obtained and cultured. RNA was isolated using RNeasy, and quality verified using an Agilent 2100 Bioanalyzer. Labeling and hybridization to Affymetrix Human Gene 1.0 ST microarray chips was performed by the Vanderbilt Genome Sciences Resource at Vanderbilt University Medical Center.
Project description:Keloid scars is a pathologic fibro-proliferative disorders of the skin, which exhibit abnormal phenotypes including fibroblasts proliferation and collagen deposits. There have been several treatments of keloids including conventional surgical therapies and adjuvant therapies, but a high recurrence rate of keloids was also observed after treatment. Quantitative proteomics approach has been proved an efficient approach to investigate pathological mechanism and novel biomarkers. In this study, we present a label-free quantitative proteomics analysis to explore differential protein expression profiles in normal skin and keloid scar tissues based on nano-liquid chromatography and tandem mass spectrometry (Nano-LC–MS/MS). The study results displayed a more comprehensive keloid protein expression landscape and provided novel pathological insight of keloid.
Project description:To study the effects of mechanical stretching on fibroblasts, two cell lines, HFF and KF, were subject to 50% uniaxial mechanical stretching for 6, 12, and 18 hours, followed by RNA-seq.
Project description:Skin fibrotic disease representsa major global healthcare burden, characterized by fibroblast hyperproliferation and excessive accumulation of extracellular matrix.Fibroblasts are found to be heterogeneous in multiple fibrotic diseases,but the fibroblast heterogeneity of skin fibrotic diseases remains unknown.In this study, we performed single-cell RNA-seq in keloid, a paradigm of skin fibrotic diseases, andnormal scardermis tissues.Our results indicate that keloid and normal scar fibroblasts could be divided into 4 subpopulations: secretory-papillary, secretory-reticular, mesenchymal and pro-inflammatory.The percentage of mesenchymal fibroblast subpopulationincreased significantly in keloid compared to normal scar. Interestingly, we also found increasing mesenchymal fibroblast subpopulation in scleroderma, another skin fibrotic disease.Function studies showed that the mesenchymal fibroblasts promoted collagen synthesis of the other fibroblasts in keloid partiallythrough secreting POSTN. These findings will help us understandskin fibroticpathogenesis in depth,and provided potential target cells for fibrotic diseases therapies.
Project description:Keloids are wounding-induced fibroproliferative human tumor–like skin scars of complex genetic makeup and poorly defined pathogenesis. Fibroblasts are the principal mediator of fibroproliferative disorders. To reveal dynamic epigenetic and transcriptome changes of keloid fibroblasts, a vertical study from RNA-seq and ATAC-seq analyses followed by in vivo confirmation of candidate molecule expression and subsequent functional testing was carried out using an early passage, freshly isolated keloid fibroblast cell strain and its paired normal control. These keloid fibroblasts produce keloid-like scars in a plasma clot-based skin equivalent humanized keloid animal model. RNA-seq analysis reveals that Hepatic fibrosis is the most significant pathway followed by Wnt–b-catenin signaling, TGF-b signaling, regulation of the EMT pathway, the STAT3 pathway, and adherens junction signaling. ATAC-seq analysis shows that STAT3 signaling is the most active pathway in keloid fibroblasts, followed by Wnt signaling (Wnt5) and regulation of the EMT pathway. Immunohistochemistry confirms that activated STAT3, (Tyr705 phospho-STAT3) and/or b-catenin are upregulated in dermal fibroblasts of keloid clinical specimens and mature keloid skin equivalent implants from the humanized mouse model compared to the normal control. The effect of STAT3 signaling on keloid fibroblast collagen expression was further tested in plasma clot-based skin equivalents using Cucurbitacin I, a selective JAK2/STAT3 inhibitor. A non-linear dose response of Cucurbitacin I was observed in collagen type I expression indicating a likely role of STAT3 signaling pathway in keloid pathogenesis. This work also demonstrates the utility of the recently established humanized keloid mouse model in exploring the mechanism of keloid formation.
Project description:We hypothesize that, the mTOR pathway is a dominant pathway in cultured keloid and hypertrophy scar fibriblasts compared to normal skin cells. Certain pathway changes can be detected after medication treatment. Global gene expression in RNA samples from rapamycin and tacrolimus treated fibroblasts (from normal skin and hypertrophic scars, keloid scars) is assayed to study the possibility to use mTOR inhibitors as potential drug to treat abnormal scarring. We investigated the difference between normal wound healing and hypertrophic scars and keloids as well.
Project description:Skin fibrotic disease representsa major global healthcare burden, characterized by fibroblast hyperproliferation and excessive accumulation of extracellular matrix.Fibroblasts are found to be heterogeneous in multiple fibrotic diseases,but the fibroblast heterogeneity of skin fibrotic diseases remains unknown.In this study, we performed single-cell RNA-seq in keloid, a paradigm of skin fibrotic diseases, andnormal scardermis tissues.Our results indicate thatkeloid and normal scar fibroblasts could be divided into 4 subpopulations: secretory-papillary, secretory-reticular, mesenchymal and pro-inflammatory.The percentage of mesenchymal fibroblast subpopulationincreased significantly in keloid compared to normal scar. Interestingly, we also found increasing mesenchymal fibroblast subpopulation in scleroderma, another skin fibrotic disease.Function studies showed that the mesenchymal fibroblasts promoted collagen synthesis of the other fibroblasts in keloid partiallythrough secreting POSTN. These findings will help us understandskin fibroticpathogenesis in depth,and provided potential target cells for fibrotic diseases therapies.
Project description:The ability of the skin to expand in response to stretching has, for decades, been exploited in reconstructive surgery. Several studies have investigated the response of stretching epidermal cells in vitro. However, it remains unclear how mechanical forces affect epidermal stem cell behaviour in vivo. Here, we develop a mouse model in which the temporal consequences of the stretching the skin epidermis can be studied. Using a multidisciplinary approach that combines clonal analysis and mathematical modelling, we show that mechanical force induces skin expansion by promoting the renewal of epidermal stem cells. This occurs through a structured response in which cell fates are coordinated locally by stem cells that switch between states primed for renewal or differentiation. Transcriptional and chromatin profiling identifies the gene regulatory networks modulated by mechanical force. Using a combination of pharmacological inhibition and several conditional gene loss-of-function mouse mutants, we dissect the signalling pathways that control force-mediated tissue expansion.
Project description:Genome wide DNA methylation profiling of normal skin and keloid samples. The Illumina Infinium 450k Human DNA methylation Beadchip v1.1 was used to obtain DNA methylation profiles across approximately 485577 CpGs in keloid and normal samples. Samples included 6 normal skin, 6 Keloid.
Project description:Genome wide DNA methylation profiling of normal skin and keloid samples. The Illumina Infinium 450k Human DNA methylation Beadchip v1.1 was used to obtain DNA methylation profiles across approximately 485577 CpGs in keloid and normal samples. Samples included 6 normal skin, 6 Keloid. Bisulphite converted DNA from the 12 samples were hybridised to the Illumina Infinium 450k Human Methylation Beadchip v1.1