Engrailed 1 coordinates cytoskeletal re-organization to induce myofibroblast differentiation
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE174580 | GEO | 2021/05/18
REPOSITORIES: GEO
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Project description:Transforming growth factor-β (TGFβ) is a key mediator of fibroblast activation in fibrotic diseases including systemic sclerosis. Here we show that Engrailed 1 (EN1) is re-expressed in multiple fibroblast subpopulations in the skin of SSc patients. We characterize EN1 as a molecular amplifier of TGFβ signaling in myofibroblast differentiation: TGFβ induces EN1 expression in a SMAD3-dependent manner, and, in turn, EN1 mediates the pro-fibrotic effects of TGFβ. RNA sequencing demonstrates that EN1 induces a pro-fibrotic gene expression profile functionally related to the cytoskeleton organization and ROCK activation. EN1 regulates gene expression by modulating the activity of SP1 and other SP-transcription factors, as confirmed by ChIP-seq experiments for EN1 and SP1. Functional experiments confirm the coordinating role of EN1 on ROCK activity and the re-organization of cytoskeleton during myofibroblast differentiation both in standard fibroblast culture systems and in in vitro skin models. Consistently, mice with fibroblast-specific knockout of En1 demonstrate impaired fibroblast-to-myofibroblast transition and are partially protected from experimental skin fibrosis.
2021-05-19 | GSE174598 | GEO
Project description:Transforming growth factor β (TGFβ) signaling is a core pathway of fibrosis, but the molecular regulation of the activation of latent TGFβ remains incompletely understood. Here, we demonstrate a crucial role of WNT5A/JNK/ROCK signaling that rapidly coordinates the activation of latent TGFβ in fibrotic diseases. WNT5A was identified as predominant non-canonical WNT ligand in fibrotic diseases such as systemic sclerosis, sclerodermatous chronic graft-versus-host disease and idiopathic pulmonary fibrosis, stimulating fibroblast-to-myofibroblast transition and tissue fibrosis by activation of latent TGFβ. The activation of latent TGFβ requires rapid JNK- and ROCK-dependent cytoskeletal rearrangements and integrin αV (ITGAV). Conditional Knockout of WNT5A or its downstream targets prevented activation of latent TGFβ, rebalanced TGFβ signaling and ameliorated experimental fibrosis. We thus uncovered a novel mechanism for the aberrant activation of latent TGFβ in fibrotic diseases and provided evidence for targeting WNT5A/JNK/ROCK signaling in fibrotic diseases as a new therapeutic approach.
2024-02-29 | GSE222916 | GEO
Project description:Objectives: The transcription factor TFAM is controlling the transcription of core proteins required for mitochondrial homeostasis. The aim of the current study was to investigate changes in TFAM expression in systemic sclerosis (SSc), to analyze mitochondrial function and to evaluate the consequences for fibroblast activation. Methods: The expression of TFAM was analyzed by immunofluorescence and Western blot. The effects of TFAM knockout were investigated in cultured fibroblasts and in bleomycin-induced skin and lung fibrosis and in TβRIact-induced skin fibrosis. Results: The expression of TFAM was downregulated in fibroblasts in SSc skin and in cultured SSc fibroblasts. The downregulation of TFAM was associated with decreased mitochondrial number and accumulation of damaged mitochondria with release of mtDNA, accumulation of deletions in mtDNA, metabolic alterations with impaired OXPHOS and release of the mitokine GDF15. Chronic, but not acute exposure of normal fibroblasts to TGFβ mimicked the finding in SSc fibroblasts with downregulation of TFAM and accumulation of mitochondrial damage. Downregulation of TFAM promotes fibroblast activation with upregulation of fibrosis-relevant GO-terms in RNASeq. Mice with fibroblast-specific knockout of TFAM are prone to fibrotic tissue remodeling with fibrotic responses even to NaCl instillation and enhanced sensitivity to bleomycin injection and TβRIact-overexpression. TFAM knockout fosters SMAD3 signaling to promote fibroblast activation. Conclusions: Alterations in the key mitochondrial transcription factor TFAM in response to prolonged activation of TGFβ and associated mitochondrial damage induce transcriptional programs that promote fibroblast-to-myofibroblast transition and drive tissue fibrosis.
2021-12-21 | GSE184356 | GEO
Project description:Skin and lung fibrosis in systemic sclerosis (SSc) is driven by myofibroblasts, alpha-smooth muscle actin (SMA) expressing cells that produce matrix as well as increase tension on surrounding tissues. Myofibroblast progenitors have been described to arise from a variety of cell types in murine fibrosis models, but relatively modest insight is available as to their source and differentiation in fibrotic human diseases. We utilize single cell RNA-sequencing to examine the transcriptome changes that occur in fibroblasts in SSc skin and during myofibroblast differentiation. We show that dermal myofibroblasts arise from an SFRP2/DPP4-expressing progenitor fibroblast population. In SSc skin, fibroblasts undergo global changes in gene expression, including SFRP2-expressing fibroblasts, which globally upregulate expression of markers, such as PRSS23 and THBS1. However, only a fraction of SSc fibroblasts differentiate into myofibroblasts, as shown by expression of additional markers, such as SFRP4 and FNDC1. These results indicate that myofibroblasts derive from a specific fibroblast subpopulation in SSc skin, that their differentiation proceeds in two stages and that other fibroblast populations also shift transcriptomes in SSc skin, suggesting a cytokine driven process. The myofibroblast transcriptome implicates upstream transcription factors that should help further unravel the drivers of myofibroblast differentiation.
2021-05-20 | GSE138669 | GEO
Project description:Objectives: Eph/Ephrin cell-cell signaling is emerging as a key player in tissue fibrogenesis. The aim of this study was to test the hypothesis that the receptor tyrosine kinase EphB2 mediates dermal fibrosis in systemic sclerosis (SSc). Methods: We assessed normal and SSc human skin biopsies for EphB2 expression. The in vivo role of EphB2 in skin fibrosis was investigated by subjecting EphB2-knockout mice to both bleomycin-induced and tight skin (Tsk1/+) genetic mouse models. EphB2 kinase-dead and overactive point mutant mice were used to evaluate the role of EphB2 forward signaling in bleomycin-induced dermal fibrosis. In vitro studies were performed on dermal fibroblasts from SSc patients and healthy controls, which was followed by in vivo analysis of fibroblast-specific EphB2 deficient mice. Results: Expression of EphB2 is upregulated in SSc skin tissue and explanted SSc dermal fibroblasts compared to healthy controls. EphB2 expression is elevated in two animal models of dermal fibrosis. In mice, EphB2 drives dermal fibrosis in both the bleomycin and the Tsk1/+ models of skin fibrosis. EphB2 forward signaling is a critical mediator of dermal fibrosis. Transforming growth factor-β (TGFβ) cytokines upregulate EphB2 in dermal fibroblasts via non-canonical TGFβ/SMAD signaling and silencing EphB2 in dermal fibroblasts is sufficient to dampen TGFβ-induced fibroblast-to-myofibroblast differentiation. Moreover, mice with fibroblast-specific deletion of EphB2 showed impaired fibroblast-to-myofibroblast differentiation and reduced skin fibrosis upon bleomycin challenge. Conclusion: Our data implicate EphB2 overexpression and kinase-mediated forward signaling in the development of dermal fibrosis in SSc. EphB2 thus represents a potential new therapeutic target for SSc.
2024-04-10 | GSE253089 | GEO
Project description:In diseased organs, stress-activated signaling cascades alter chromatin, triggering broad shifts in transcription and cell state that exacerbate pathology. Fibroblast activation is a common stress response that worsens lung, liver, kidney and heart disease, yet its mechanistic basis remains poorly understood. Pharmacologic inhibition of the BET family of transcriptional coactivators alleviates cardiac dysfunction and associated fibrosis, providing a tool to mechanistically interrogate maladaptive fibroblast states and modulate their plasticity as a potential therapeutic approach. Here, we leverage dynamic single cell transcriptomic and epigenomic interrogation of heart tissue with and without BET inhibition to reveal a reversible transcriptional switch underlying stress-induced fibroblast activation. Transcriptomes of resident cardiac fibroblasts demonstrated robust and rapid toggling between the quiescent fibroblast and activated myofibroblast state in a manner that directly correlated with BET inhibitor exposure and cardiac function. Correlation of single cell chromatin accessibility with cardiac function revealed a novel set of reversibly accessible DNA elements that correlated with disease severity. Among the most dynamic elements was an enhancer regulating the transcription factor MEOX1, which was specifically expressed in activated myofibroblasts, occupied putative regulatory elements of a broad fibrotic gene program, and was required for TGFβ-induced myofibroblast activation. CRISPR interference of the most dynamic cis-element within the enhancer, marked by nascent transcription, prevented TGFβ-induced activation of Meox1. These findings identify MEOX1 as a central regulator of stress-induced myofibroblast activation associated with cardiac dysfunction. The plasticity and specificity of the BET-dependent regulation of MEOX1 in endogenous tissue fibroblasts provides new trans- and cis- targets for treating fibrotic disease.
2021-09-30 | GSE183343 | GEO
Project description:Dynamic fibroblast state transitions underlie the heart’s fibrotic response, raising the possibility that tactical control of these transitions could alter maladaptive fibrotic outcomes. Transcriptome maturation by Muscleblind-like 1 (MBNL1) has emerged as a driver of differentiated cell states. Indeed, MBNL1 expression is elevated in conjunction with profibrotic transcripts in lineage traced myofibroblasts and modeling this gain in function by fibroblast-specific overexpression of an MBNL1 transgene induced a myofibroblast transcriptional identity in healthy hearts and promoted maladaptive myocyte remodeling and scar maturation following injury. Both fibroblast-specific and myofibroblast-specific loss of MBNL1 limited scar production and maturation, which was ascribed to negligible myofibroblast activity. MBNL1 deletion drove expansion of all quiescent cardiac fibroblast states and promoted mesenchymal stem cell characteristics while forced MBNL1 expression restricted state diversity by transitioning most fibroblasts to the most mature myofibroblast identity. These data suggest MBNL1 is a post-transcriptional switch controlling quiescent to myofibroblast transitions during cardiac wound healing.
2022-01-20 | GSE193308 | GEO
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.
2023-02-23 | PXD035749 | Pride
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
2016-04-06 | GSE77474 | GEO