Project description:This study contains RNA-seq analysis of neonatal dermal fibroblasts from mice with Fbn1 G234D/G234D mutation to uncover its impact on ECM gene expression, potentially shedding light on the tight skin phenotype. While both wild-type (WT) and mutant fibroblasts showed differences, two of the mutants exhibited more significant changes, aligning with the early onset of the disease. These earlier data was deposited in GSE268383. In this study we added 2 more wild type fibroblasts and 3 more homozygous mutant cells to ascertain the features we obtained prevously. As previously noted, there was no obvious change in ECM and ECM-modifying genes, such as the LOX family, Fbn1, and TGFβ/BMP signaling genes; while the mutants displayed upregulation of muscle developmental genes (e.g., Myod1, Myog, Myh family), immune response, and cell-cell adhesion/cytoskeletal genes. In line with previous data, downregulated genes were still enriched for histone genes and developmental transcription factors, hinting at potential chromatin/transcriptional state modifications underlying the tight skin phenotype. These transcriptomic findings underscore the need for further investigation into the mechanobiological implications of Fbn1G234D/G234D fibroblasts.
Project description:One of the keys to achieving skin regeneration lies within understanding the heterogeneity of neonatal fibroblasts, which support skin regeneration. However, the molecular underpinnings regulating the cellular states and fates of these cells are not fully understood. To investigate this, we performed a parallel multi-omics analysis by processing neonatal murine skin for single-cell ATAC-sequencing (scATAC-seq) and single-cell RNA-sequencing (scRNA-seq) separately. Our approach revealed that fibroblast clusters could be sorted into papillary and reticular lineages based on transcriptome profiling, as previously published. However, scATAC-seq analysis of neonatal fibroblast lineage markers, such as, Dpp4/CD26, Corin, and Dlk1 along with markers of myofibroblasts, revealed accessible chromatin in all fibroblast populations despite their lineage specific transcriptome profiles. These results suggests that accessible chromatin does not always translate to gene expression and that many fibroblast lineage markers reflect a fibroblast state, which includes neonatal papillary, reticular, and myofibroblasts. This analysis also provides a possible explanation as to why these marker genes can be promiscuously expressed in different fibroblast populations under different conditions. Our scATAC-seq analysis also revealed that the functional lineage restriction between dermal papilla and adipocytes fates are regulated by distinct chromatin landscapes. Finally, we have developed a webtool for our multi-omics analysis: https://skinregeneration.org/scatacseq-and-scrnaseq-data-from-thompson-et-al-2021-2/.
Project description:Inflammation early in life can prime the local immune milieu of peripheral tissues, causing lasting changes in immunologic tone that confer disease protection or susceptibility. The cellular and molecular mechanisms that incite changes in immune tone in many nonlymphoid tissues remain largely unknown. We find that time-limited neonatal inflammation induced by transient reduction of neonatal regulatory T cells (Tregs) causes a dramatic dysregulation of subcutaneous tissue in murine skin, accompanied by the selective accumulation of Th2 cells within a distinct microanatomic niche. Th2 cells are maintained into adulthood through interactions with a fibroblast population in skin fascia that we refer to as Th2-interacting fascial fibroblasts (TIFFs), which expand in response to Th2 cytokines to form subcutaneous fibrous bands. Activation of the Th2-TIFF niche by neonatal inflammation primes skin for altered reparative responses to wounding. We further identify fibroblasts in healthy human skin expressing the TIFF transcriptional signature and find these cells at high levels in eosinophilic fasciitis, an orphan disease characterized by inflammation and fibrosis of the skin fascia. Taken together, these data define a novel Th2 niche in skin, functionally characterize a disease-associated fibroblast population, and suggest a mechanism of immunologic priming whereby inflammation early in life creates networks between adaptive immune cells and stromal cells, establishing an immunological set-point in tissues that is maintained throughout life.
Project description:A fibrotic environment supports cancer growth. Our aim is to assess the transcriptomic differences by performing RNA sequencing in a fibrosis mouse model to provide insight into the increased growth of ovarian cancer in Fbn1 Tsk mice. Elucidating the targets important in fibrosis could provide potential clues to the mechanism of preferential cancer growth in fibrotic environments.
Project description:Purpose: The goals of this study were to identify preferential gene expression signatures that are unique to Tregs in neonatal skin relative to peripheral Tregs Methods: Tregs from telogen skin and SDLNs were purified by cell sorting (using the Treg GFP reporter mouse line Foxp3-DTR/GFP) to generate mRNA transcription profiles. Results: Transcriptional profiling revealed a unique neonatal skin Treg signature relative to SDLN Tregs Conclusion: Our study represents the first detailed analysis of the neonatal skin Treg transcriptome.
Project description:Pericryptal myofibroblasts in the colon and rectum play an important role in regulating the normal colorectal stem cell niche and facilitating tumour progression. Myofibroblasts have previously mostly been distinguished from normal fibroblasts only by the expression of α smooth muscle actin (αSMA). We now identify AOC3, a surface monoamine oxidase, as a new marker of myofibroblasts by showing that it is the target protein of the myofibroblast reacting monoclonal antibody (mAb), PR2D3. The normal and tumour tissue distribution and the cell line reactivity of AOC3 match that expected for myofibroblasts. We have shown that the surface expression of AOC3 is sensitive to digestion by trypsin and collagenase and that anti-AOC3 antibodies can be used for FACS sorting of myofibroblasts obtained by non-enzymatic procedures. Whole genome microarray mRNA expression profiles of myofibroblasts and skin fibroblasts revealed four additional genes that are significantly expressed differentially between these two cell types; NKX2-3 and LRRC17 are expressed in myofibroblasts and SHOX2 and TBX5 in skin fibroblasts. Transforming Growth Factor β (TGFβ) substantially down-regulated AOC3 expression in myofibroblasts but not in skin fibroblasts, in which it dramatically increased the expression of αSMA. A knockdown of NKX2-3 in myofibroblasts caused a decrease of myofibroblast-related gene expression and an increased expression of the fibroblast associated gene, SHOX2, suggesting that NKX2-3 is a key mediator for maintaining myofibroblast characteristics. Our results show that colorectal myofibroblasts, as defined by the expression of AOC3, NKX2-3 and other markers, are a distinctly different cell type from TGFβ activated fibroblasts. colorectal myofibroblast specific markers and expression profiles were sought by comparing four primary myofibroblast cultures to a panel of four dermal and foreskin fibroblast cell lines Four primary myofibroblast cultures established from adult human colon compared to four skin fibroblast cell lines to identify intestinal myofibroblast specific markers
Project description:Mitral valves were isolated from 2-month-old mice with the following 4 genotypes: 1) CCR2 RFP/+ (Chet), 2) CCR2 RFP/RFP (Cko), 3) Fbn1 C1039G/+; CCR2 RFP/+ (FhetChet), 4) Fbn1 C1039G/+; CCR2 RFP/RFP (FhetCko). N=4 for each genotype. Total RNA was extracted from mitral valves individually for gene expression profiling.
Project description:During aging, stromal functions are thought to be impaired, yet little is known whether this stems from molecular and cellular changes of fibroblasts, a major component of stroma. Using population- and single-cell whole transcriptomics, and long-term lineage tracing, we studied alterations in murine dermal fibroblasts during physiological aging under different dietary regimes known to affect longevity. We show that the identity of aged fibroblasts becomes undefined, with the distinct fibroblast states present in young skin no longer clearly demarcated. In addition, old fibroblasts not only reduce the expression of genes involved in the formation of the extracellular matrix, but intriguingly, also gain adipogenic traits, paradoxically becoming similar to neonatal pro-adipogenic fibroblasts. These age-related alterations are sensitive to systemic changes in metabolism: long-term caloric restriction prevents them in old fibroblasts in a reversible manner, whereas a high-fat diet potentiates them in young fibroblasts. Finally, inhibition of the master regulator of adipogenesis, PPARgamma, attenuates fibroblast aging in vivo, providing potential anti-aging therapeutic alternatives to caloric restriction.