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: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: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:Keloids are scar tissue that can develop under tensile stress and manifest the tactile itch called alloknesis due to the heterogeneous course. But the molecular and cellular mechanisms underlying the pathology of keloid have been still unknown. Here, we found that unique fibroblast subpopulation that have dense-core granules with enhanced expression of PIEZO2 in the dermal layer of keloid tissue with alloknesis, a pressure-tactile itch. PIEZO2-expressed fibroblasts showed enhanced expression of COL1A1, COL1A2 and COL3A1. Gene expression profile analysis of fibrous disease tissues could distinguish the keloid cases by higher PIEZO2, which correlated with collagen COL1A1, COL1A2, and COL3A1 gene expression, not only from the keloid cases with lower PIEZO2 expression but also from the lymphedema cases where massive fibroblast proliferation appears. Notably, patients with the keloid accompanied by higher expression of PIEZO2 showed a significantly shorter time to recurrence after keloidectomy in patients with the keloids (4/5 vs. 0/5, p = 0.047). Thus, a unique subset of PIEZO2-positive fibroblasts may be involved in a keloid pathology and be a potent therapeutic target for the intractable keloids.
Project description:Keloids are scar tissue that can develop under tensile stress and manifest the tactile itch called alloknesis due to the heterogeneous course. But the molecular and cellular mechanisms underlying the pathology of keloid have been still unknown. Here, we found that unique fibroblast subpopulation that have dense-core granules with enhanced expression of PIEZO2 in the dermal layer of keloid tissue with alloknesis, a pressure-tactile itch. PIEZO2-expressed fibroblasts showed enhanced expression of COL1A1, COL1A2 and COL3A1. Gene expression profile analysis of fibrous disease tissues could distinguish the keloid cases by higher PIEZO2, which correlated with collagen COL1A1, COL1A2, and COL3A1 gene expression, not only from the keloid cases with lower PIEZO2 expression but also from the lymphedema cases where massive fibroblast proliferation appears. Notably, patients with the keloid accompanied by higher expression of PIEZO2 showed a significantly shorter time to recurrence after keloidectomy in patients with the keloids (4/5 vs. 0/5, p = 0.047). Thus, a unique subset of PIEZO2-positive fibroblasts may be involved in a keloid pathology and be a potent therapeutic target for the intractable keloids.
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:This study investigated the effects of extracellular matrix (ECM) rigidty on gene expression patterns in normal dermal fibroblasts (NDFs) and keloid dermal fibroblasts (KDFs). Cells were cultured on collagen coated polyacrylamide hydrogels with elastic moduli mimicking normal skin (8 kPa) or keloid scar tissue (214 kPa), and changes in gene expression were profiled using next-generation RNA-sequencing. Differential gene expression analysis identified overall significant differences in gene expression between the NDF and KDF populations. Despite high levels of inter-patient heterogeneity in the KDF samples, further principal components analysis revealed a subset of genes (PC5) that were specifically regulated by ECM rigidity. Gene set enrichment analysis of the PC5 genes identified classic pathways associated with mechanotransduction, including Hippo Signalling and Regulation of the Actin Cytoskeleton, as well as genes associated with the Autophagy pathway. Additional in vitro studies and human tissue staining confirmed the biomechanical regulation of autophagic flux in NDFs and KDFs and differential remodelling of the lysosome in KDFs and keloid scars. Together, these findings implicate autophagy and lysosomal remodelling as biomechanically dysregulated pathways in keloid fibroblasts, and these mechanisms may contribute to scar pathogenesis.