Project description:3mm punch biopsies were taken from a healed normotrophic scar and a contralateral matched control site in burn patients with a scar at least 1 year old. Fibroblasts were cultured from explants to passage 2 and RNA was extracted and run on expression arrays to examine differences in scar and control fibroblast gene expression Normotrophic scar maintains its abnormal scar phenotype for the rest of the patients life, long after the injury has healed. Differences in gene expression may reaveal target genes that can be modulated to improve scar appearance
Project description:3mm punch biopsies were taken from a healed normotrophic scar and a contralateral matched control site in burn patients with a scar at least 1 year old. Fibroblasts were cultured from explants to passage 2 and DNA was extracted and run on methylation arrays to examine differences in scar and control fibroblast gene expression Normotrophic scar maintains its abnormal scar phenotype for the rest of the patients life, long after the injury has healed. Differences in gene expression may reaveal target genes that can be modulated to improve scar appearance
Project description:The goal of this study is to compare the different characteristics of fibroblasts from normal, hypertrophic and keloid scar through RNA-seq.
Project description:Scar tissue that forms in the heart after cardiac injury, comprises an abundant number of non-excitable fibroblasts in close proximity to excitable myocytes, that are embedded within the matrix of the scar. Electrical coupling of fibroblasts and myocytes is known to occur and in vitro simulation studies have demonstrated that changes in fibroblast membrane potential can lead to myocyte excitability and susceptibility to arrhythmogenesis. However, the physiologic significance of electrical coupling between myocytes and fibroblasts in scar tissue, in the regulation of cardiac excitability and arrhythmogenesis in vivo is hotly debated and has never been demonstrated. Here, we genetically engineer a mouse that expresses the optogenetic cationic channel ChR2 exclusively in cardiac fibroblasts and not in cardiac myocytes. We subject the animal to cardiac injury and demonstrate that optical stimulation of scar tissue elicits cardiac excitability and induces arrhythmias. Connexin 43 (Cx43) is a gap junctional protein that is the most abundant connexin isoform in the heart and thought to mediate electrical coupling of fibroblasts and myocytes. Using genetic loss of function approaches, we show that Cx43 is not necessary for fibroblast-myocyte electrical coupling in vivo. CRISPR/Cas 9 mediated sequential deletion of the other highly expressed connexins also did not affect electrical coupling of fibroblasts and myocytes. Using computational modeling approaches, we show that gap junctional and non-gap junctional coupling mechanisms synergize in a functionally redundant manner to excite myocytes coupled to fibroblasts. These observations demonstrate that cardiac fibroblasts in scar tissue directly regulate cardiac excitability in vivo and can induce arrhythmogenesis. Our findings throw insight into the importance of electrical coupling of fibroblasts and myocytes in the genesis of scar associated cardiac arrhythmias.
Project description:3mm punch biopsies were taken from a healed normotrophic scar in burn patients with a scar at least 1 year old and fibroblasts were cultured from explants. Previous transcriptomic and epigenomic work found MKX and FOXF2 genes were overexpressed and these were knocked down using siRNA. RNA was then extracted and analysed using RNAseq to determine genes and pathways affected by this knockdown
Project description:Dipeptidyl peptidase 4 (Dpp4) plays a pivotal role in fibrotic and nonfunctional scar development following skin injury and is present in a subset of fibroblasts implicated in scar formation. Simultaneously, heterogeneous vascular endothelial cells (ECs) retain their capacity to drive tissue regeneration and repair within scarred areas. Effective strategies for inhibiting scar-associated fibroblasts and regulating EC subtypes in the scar microenvironment remain unclear. Here, we engineered CAR-Trem2-Ms capable of targeting DPP4+ fibroblasts and modulating EC phenotypes within the scar microenvironment to effectively prevent and treat scarring. Furthermore, compared to those in normal control samples, DPP4 expression levels were higher in both clinical scar databases and samples from scar patients. We transferred a CAR gene specifically targeting Dpp4+ fibroblasts into macrophages, which were then induced into CAR-Trem2-Ms with 1,25-dihydroxycholecalciferol (an active form of VD, VD3). Hydrogel micropore microneedles (mMNs) were employed to deliver CAR-Trem2-Ms to effectively alleviate scar formation. Single-cell transcriptome sequencing and analysis revealed that CAR-Trem2-Ms could modify EC phenotypes and regulate fibrosis by suppressing the profibrotic gene Lrg1. CAR-Trem2-Ms effectively inhibited fibrosis in fibroblasts induced by high EC LRG1 expression in vitro, further revealing the underlying mechanism by which CAR-Trem2-Ms exert their antifibrotic effects. Our findings offer a promising approach for treating post-traumatic scarring and provide novel insights into the pathological mechanisms underlying fibrosis.
Project description:Dipeptidyl peptidase 4 (Dpp4) plays a pivotal role in fibrotic and nonfunctional scar development following skin injury and is present in a subset of fibroblasts implicated in scar formation. Simultaneously, heterogeneous vascular endothelial cells (ECs) retain their capacity to drive tissue regeneration and repair within scarred areas. Effective strategies for inhibiting scar-associated fibroblasts and regulating EC subtypes in the scar microenvironment remain unclear. Here, we engineered CAR-Trem2-Ms capable of targeting DPP4+ fibroblasts and modulating EC phenotypes within the scar microenvironment to effectively prevent and treat scarring. Furthermore, compared to those in normal control samples, DPP4 expression levels were higher in both clinical scar databases and samples from scar patients. We transferred a CAR gene specifically targeting Dpp4+ fibroblasts into macrophages, which were then induced into CAR-Trem2-Ms with 1,25-dihydroxycholecalciferol (an active form of VD, VD3). Hydrogel micropore micro
Project description:Excessive repair after burn or trauma will lead to the formation of pathological scar. TGF-β1 is a powerful growth factor after wound healing. It is considered to be a key regulator of HS and various fibrotic diseases. MicroRNAs (miRNAs) can widely participate in the pathophysiological processes of various diseases by participating in post transcriptional gene regulation. At present, there is no research report on miR-361 and hypertrophic scar. This study found that miR-361 in HS is down-regulated. MiR-361 can inhibit the proliferation of HS fibroblasts and promote their apoptosis by inhibiting TGF-β1. Moreover, miR-361 can inhibit the formation of rabbit ear scar by inhibiting the expression of TGF-β1.