Acyltransferase skinny hedgehog regulates TGFβ-dependent fibroblast activation in SSc

2019 ◽  
Vol 78 (9) ◽  
pp. 1269-1273 ◽  
Author(s):  
Ruifang Liang ◽  
Rosebeth Kagwiria ◽  
Ariella Zehender ◽  
Clara Dees ◽  
Christina Bergmann ◽  
...  
Keyword(s):  
Long Range ◽  
Transforming Growth Factor ◽  
Human Fibroblasts ◽  
Transforming Growth Factor Β ◽  
Dermal Fibroblasts ◽  
Myofibroblast Differentiation ◽  
Dependent Manner ◽  
Hedgehog Signalling ◽  
Fibroblast Activation ◽  
Novel Approach

ObjectivesSystemic sclerosis (SSc) is characterised by aberrant hedgehog signalling in fibrotic tissues. The hedgehog acyltransferase (HHAT) skinny hedgehog catalyses the attachment of palmitate onto sonic hedgehog (SHH). Palmitoylation of SHH is required for multimerisation of SHH proteins, which is thought to promote long-range, endocrine hedgehog signalling. The aim of this study was to evaluate the role of HHAT in the pathogenesis of SSc.MethodsExpression of HHAT was analysed by real-time polymerase chain reaction(RT-PCR), immunofluorescence and histomorphometry. The effects of HHAT knockdown were analysed by reporter assays, target gene studies and quantification of collagen release and myofibroblast differentiation in cultured human fibroblasts and in two mouse models.ResultsThe expression of HHAT was upregulated in dermal fibroblasts of patients with SSc in a transforming growth factor-β (TGFβ)/SMAD-dependent manner. Knockdown of HHAT reduced TGFβ-induced hedgehog signalling as well as myofibroblast differentiation and collagen release in human dermal fibroblasts. Knockdown of HHAT in the skin of mice ameliorated bleomycin-induced and topoisomerase-induced skin fibrosis.ConclusionHHAT is regulated in SSc in a TGFβ-dependent manner and in turn stimulates TGFβ-induced long-range hedgehog signalling to promote fibroblast activation and tissue fibrosis. Targeting of HHAT might be a novel approach to more selectively interfere with the profibrotic effects of long-range hedgehog signalling.

PGC-1α regulates autophagy to promote fibroblast activation and tissue fibrosis

2020 ◽  
Vol 79 (9) ◽  
pp. 1227-1233 ◽  
Author(s):  
Yun Zhang ◽  
Lichong Shen ◽  
Honglin Zhu ◽  
Katja Dreissigacker ◽  
Diana Distler ◽  
...  
Keyword(s):  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Therapeutic Potential ◽  
Human Fibroblasts ◽  
Dermal Fibroblasts ◽  
Skin Fibrosis ◽  
Type I ◽  
Myofibroblast Differentiation ◽  
Tissue Fibrosis ◽  
Fibroblast Activation

ObjectivesCoactivators are a heterogeneous family of transcriptional regulators that are essential for modulation of transcriptional outcomes and fine-tune numerous cellular processes. The aim of the present study was to evaluate the role of the coactivator peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) in the pathogenesis of systemic sclerosis (SSc).MethodsExpression of PGC-1α was analysed by real-time PCR, western blot and immunofluorescence. Modulation of autophagy was analysed by reporter studies by expression of autophagy-related genes. The effects of PGC-1α knockdown on collagen production and myofibroblast differentiation were analysed in cultured human fibroblasts and in two mouse models with fibroblast-specific knockout of PGC-1α.ResultsThe expression of PGC-1α was induced in dermal fibroblasts of patients with SSc and experimental murine fibrosis. Transforming growth factor beta (TGFβ), hypoxia and epigenetic mechanisms regulate the expression of PGC-1α in fibroblasts. Knockdown of PGC-1α prevented the activation of autophagy by TGFβ and this translated into reduced fibroblast-to-myofibroblast differentiation and collagen release. Knockout of PGC-1α in fibroblasts prevented skin fibrosis induced by bleomycin and by overexpression of a constitutively active TGFβ receptor type I. Moreover, pharmacological inhibition of PGC-1α by SR18292 induced regression of pre-established, bleomycin-induced skin fibrosis.ConclusionPGC-1α is upregulated in SSc and promotes autophagy to foster TGFβ-induced fibroblast activation. Targeting of PGC-1α prevents aberrant autophagy, inhibits fibroblast activation and tissue fibrosis and may over therapeutic potential.

scholarly journals TRPV4 ion channel is a novel regulator of dermal myofibroblast differentiation

2017 ◽  
Vol 312 (5) ◽  
pp. C562-C572 ◽  
Author(s):  
Shweta Sharma ◽  
Rishov Goswami ◽  
Michael Merth ◽  
Jonathan Cohen ◽  
Kai Y. Lei ◽  
...  
Keyword(s):  
Ion Channel ◽  
Transient Receptor Potential ◽  
Transforming Growth Factor ◽  
Dermal Fibroblasts ◽  
Transient Receptor Potential Vanilloid ◽  
Myofibroblast Differentiation ◽  
Dependent Manner ◽  
Matrix Stiffness ◽  
Functional Link ◽  
Genetic Ablation

Scleroderma is a multisystem fibroproliferative disease with no effective medical treatment. Myofibroblasts are critical to the fibrogenic tissue repair process in the skin and many internal organs. Emerging data support a role for both matrix stiffness, and transforming growth factor β1 (TGFβ1), in myofibroblast differentiation. Transient receptor potential vanilloid 4 (TRPV4) is a mechanosensitive ion channel activated by both mechanical and biochemical stimuli. The objective of this study was to determine the role of TRPV4 in TGFβ1- and matrix stiffness-induced differentiation of dermal fibroblasts. We found that TRPV4 channels are expressed and functional in both human (HDF) and mouse (MDF) dermal fibroblasts. TRPV4 activity (agonist-induced Ca2+ influx) was induced by both matrix stiffness and TGFβ1 in dermal fibroblasts. TGFβ1 induced expression of TRPV4 proteins in a dose-dependent manner. Genetic ablation or pharmacological antagonism of TRPV4 channel abrogated Ca2+ influx and both TGFβ1-induced and matrix stiffness-induced myofibroblast differentiation as assessed by 1) α-smooth muscle actin expression/incorporation into stress fibers, 2) generation of polymerized actin, and 3) expression of collagen-1. We found that TRPV4 inhibition abrogated TGFβ1-induced activation of AKT but not of Smad2/3, suggesting that the mechanism by which profibrotic TGFβ1 signaling in dermal fibroblasts is modified by TRPV4 may be through non-Smad pathways. Altogether, these data identify a novel reciprocal functional link between TRPV4 activation and TGFβ1 signals regulating dermal myofibroblast differentiation. These findings suggest that therapeutic inhibition of TRPV4 activity may provide a targeted approach to the treatment of scleroderma.

scholarly journals Engrailed 1 coordinates cytoskeletal reorganization to induce myofibroblast differentiation

2021 ◽  
Vol 218 (9) ◽  
Author(s):  
Andrea-Hermina Györfi ◽  
Alexandru-Emil Matei ◽  
Maximilian Fuchs ◽  
Chunguang Liang ◽  
Aleix Rius Rigau ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Myofibroblast Differentiation ◽  
Dependent Manner ◽  
Cytoskeleton Organization ◽  
Fibrotic Diseases ◽  
Sp Transcription Factors

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 reexpressed 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 profibrotic effects of TGFβ. RNA sequencing demonstrates that EN1 induces a profibrotic gene expression profile functionally related to 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 reorganization of cytoskeleton during myofibroblast differentiation, in both standard fibroblast culture systems and 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.

scholarly journals Tribbles homologue 3 stimulates canonical TGF-β signalling to regulate fibroblast activation and tissue fibrosis

2015 ◽  
Vol 75 (3) ◽  
pp. 609-616 ◽  
Author(s):  
Michal Tomcik ◽  
Katrin Palumbo-Zerr ◽  
Pawel Zerr ◽  
Barbora Sumova ◽  
Jerome Avouac ◽  
...  
Keyword(s):  
Cell Activation ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Dependent Manner ◽  
Cultured Fibroblasts ◽  
Fibroblast Activation ◽  
Modulation Of Gene Expression ◽  
Β Receptor ◽  
Interfering Rna

ObjectivesTribbles homologue 3 (TRB3) is a pseudokinase that modifies the activation of various intracellular signalling pathways to control fundamental processes extending from mitosis and cell activation to apoptosis and modulation of gene expression. Here, we aimed to analyse the role of TRB3 in fibroblast activation in systemic sclerosis (SSc).MethodsThe expression of TRB3 was quantified by quantitative PCR, western blot and immunohistochemistry. The role of TRB3 was analysed in cultured fibroblasts and in experimental fibrosis using small interfering RNA (siRNA)-mediated knockdown and overexpression of TRB3.ResultsTRB3 expression was increased in fibroblasts of patients with SSc and in murine models of SSc in a transforming growth factor-β (TGF-β)/Smad-dependent manner. Overexpression of TRB3 stimulated canonical TGF-β signalling and induced an activated phenotype in resting fibroblasts. In contrast, knockdown of TRB3 reduced the profibrotic effects of TGF-β and decreased the collagen synthesis. Moreover, siRNA-mediated knockdown of TRB3 exerted potent antifibrotic effects and ameliorated bleomycin as well as constitutively active TGF-β receptor I-induced fibrosis with reduced dermal thickening, decreased hydroxyproline content and impaired myofibroblast differentiation.ConclusionsThe present study characterises TRB3 as a novel profibrotic mediator in SSc. TGF-β induces TRB3, which in turn activates canonical TGF-β/Smad signalling and stimulates the release of collagen, thereby inducing a positive feedback loop that may contribute to aberrant TGF-β signalling in SSc.

scholarly journals Osteogenic Response to Polysaccharide Nanogel Sheets of Human Fibroblasts After Conversion Into Functional Osteoblasts by Direct Phenotypic Cell Reprogramming

2021 ◽  
Vol 9 ◽  
Author(s):  
Kei Nakai ◽  
Kenta Yamamoto ◽  
Tsunao Kishida ◽  
Shin-ichiro Kotani ◽  
Yoshiki Sato ◽  
...  
Keyword(s):  
Transforming Growth Factor ◽  
Human Fibroblasts ◽  
Control Cell ◽  
Transforming Growth Factor Β ◽  
Dermal Fibroblasts ◽  
Control Group ◽  
Raman Spectroscopic ◽  
Freeze Dried ◽  
Osteogenic Response ◽  
Significant Difference

Human dermal fibroblasts (HDFs) were converted into osteoblasts using a ALK inhibitor II (inhibitor of transforming growth factor-β signal) on freeze-dried nanogel-cross-linked porous (FD-NanoClip) polysaccharide sheets or fibers. Then, the ability of these directly converted osteoblasts (dOBs) to produce calcified substrates and the expression of osteoblast genes were analyzed in comparison with osteoblasts converted by exactly the same procedure but seeded onto a conventional atelocollagen scaffold. dOBs exposed to FD-NanoClip in both sheet and fiber morphologies produced a significantly higher concentration of calcium deposits as compared to a control cell sample (i.e., unconverted fibroblasts), while there was no statistically significant difference in calcification level between dOBs exposed to atelocollagen sheets and the control group. The observed differences in osteogenic behaviors were interpreted according to Raman spectroscopic analyses comparing different polysaccharide scaffolds and Fourier transform infrared spectroscopy analyses of dOB cultures. This study substantiates a possible new path to repair large bone defects through a simplified transplantation procedure using FD-NanoClip sheets with better osteogenic outputs as compared to the existing atelocollagen scaffolding material.

scholarly journals The histone demethylase Jumonji domain-containing protein 3 (JMJD3) regulates fibroblast activation in systemic sclerosis

2017 ◽  
Vol 77 (1) ◽  
pp. 150-158 ◽  
Author(s):  
Christina Bergmann ◽  
Amelie Brandt ◽  
Benita Merlevede ◽  
Ludwig Hallenberger ◽  
Clara Dees ◽  
...  
Keyword(s):  
Systemic Sclerosis ◽  
Transforming Growth Factor Beta ◽  
Topoisomerase I ◽  
Transforming Growth Factor ◽  
Dermal Fibroblasts ◽  
Dependent Manner ◽  
Murine Models ◽  
Cultured Fibroblasts ◽  
Pharmacological Inhibition ◽  
Fibroblast Activation

ObjectivesSystemic sclerosis (SSc) fibroblasts remain activated even in the absence of exogenous stimuli. Epigenetic alterations are thought to play a role for this endogenous activation. Trimethylation of histone H3 on lysine 27 (H3K27me3) is regulated by Jumonji domain-containing protein 3 (JMJD3) and ubiquitously transcribed tetratricopeptide repeat on chromosome X (UTX) in a therapeutically targetable manner. The aim of this study was to explore H3K27me3 demethylases as potential targets for the treatment of fibrosis.MethodsJMJD3 was inactivated by small interfering RNA-mediated knockdown and by pharmacological inhibition with GSKJ4. The effects of targeted inactivation of JMJD3 were analysed in cultured fibroblasts and in the murine models of bleomycin-induced and topoisomerase-I (topoI)-induced fibrosis. H3K27me3 at the FRA2 promoter was analysed by ChIP.ResultsThe expression of JMJD3, but not of UTX, was increased in fibroblasts in SSc skin and in experimental fibrosis in a transforming growth factor beta (TGFβ)-dependent manner. Inactivation of JMJD3 reversed the activated fibroblast phenotype in SSc fibroblasts and prevented the activation of healthy dermal fibroblasts by TGFβ. Pharmacological inhibition of JMJD3 ameliorated bleomycin-induced and topoI-induced fibrosis in well-tolerated doses. JMJD3 regulated fibroblast activation in a FRA2-dependent manner: Inactivation of JMJD3 reduced the expression of FRA2 by inducing accumulation of H3K27me3 at the FRA2 promoter. Moreover, the antifibrotic effects of JMJD3 inhibition were reduced on knockdown of FRA2.ConclusionWe present first evidence for a deregulation of JMJD3 in SSc. JMJD3 modulates fibroblast activation by regulating the levels of H3K27me3 at the promoter of FRA2. Targeted inhibition of JMJD3 limits the aberrant activation of SSc fibroblasts and exerts antifibrotic effects in two murine models.

The transcription factor GLI2 as a downstream mediator of transforming growth factor-β-induced fibroblast activation in SSc

2016 ◽  
Vol 76 (4) ◽  
pp. 756-764 ◽  
Author(s):  
Ruifang Liang ◽  
Barbora Šumová ◽  
Cinzia Cordazzo ◽  
Tatjana Mallano ◽  
Yun Zhang ◽  
...  
Keyword(s):  
Growth Factor ◽  
Pulmonary Fibrosis ◽  
Transforming Growth Factor ◽  
Critical Role ◽  
Transforming Growth Factor Β ◽  
Nuclear Accumulation ◽  
Dependent Manner ◽  
Cultured Fibroblasts ◽  
Hedgehog Signalling ◽  
Canonical Pathways

ObjectivesHedgehog signalling plays a critical role during the pathogenesis of fibrosis in systemic sclerosis (SSc). Besides canonical hedgehog signalling with smoothened (SMO)-dependent activation of GLI transcription factors, GLI can be activated independently of classical hedgehog ligands and receptors (so-called non-canonical pathways). Here, we aimed to evaluate the role of non-canonical hedgehog signalling in SSc and to test the efficacy of direct GLI inhibitors that target simultaneously canonical and non-canonical hedgehog pathways.MethodsThe GLI inhibitor GANT-61 was used to inhibit canonical as well as non-canonical hedgehog signalling, while the SMO inhibitor vismodegib was used to selectively target canonical hedgehog signalling. Furthermore, GLI2 was selectively depleted in fibroblasts using the Cre-LoxP system. The effects of pharmacological or genetic of GLI2 on transforming growth factor-β (TGF-β) signalling were analysed in cultured fibroblasts, in bleomycin-induced pulmonary fibrosis and in mice with overexpression of a constitutively active TGF-β receptor I.ResultsTGF-β upregulated GLI2 in a Smad3-dependent manner and induced nuclear accumulation and DNA binding of GLI2. Fibroblast-specific knockout of GLI2 protected mice from TBRact-induced fibrosis. Combined targeting of canonical and non-canonical hedgehog signalling with direct GLI inhibitors exerted more potent antifibrotic effects than selective targeting of canonical hedgehog signalling with SMO inhibitors in experimental dermal and pulmonary fibrosis.ConclusionsOur data demonstrate that hedgehog pathways and TGF-β signalling both converge to GLI2 and that GLI2 integrates those signalling to promote tissue fibrosis. These findings may have translational implications as non-selective inhibitors of GLI2 are in clinical use and selective molecules are currently in development.

Intracisternal administration of transforming growth factor-β evokes fever through the induction of cyclooxygenase-2 in brain endothelial cells

2008 ◽  
Vol 294 (1) ◽  
pp. R266-R275 ◽  
Author(s):  
Shigenobu Matsumura ◽  
Tetsuro Shibakusa ◽  
Teppei Fujikawa ◽  
Hiroyuki Yamada ◽  
Kiyoshi Matsumura ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Growth Factor ◽  
Proinflammatory Cytokines ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Cyclooxygenase 2 ◽  
Dependent Manner ◽  
Cox 2 ◽  
Β Receptor

Transforming growth factor-β (TGF-β), a pleiotropic cytokine, regulates cell proliferation, differentiation, and apoptosis, and plays a key role in development and tissue homeostasis. TGF-β functions as an anti-inflammatory cytokine because it suppresses microglia and B-lymphocyte functions, as well as the production of proinflammatory cytokines. However, we previously demonstrated that the intracisternal administration of TGF-β induces fever like that produced by proinflammatory cytokines. In this study, we investigated the mechanism of TGF-β-induced fever. The intracisternal administration of TGF-β increased body temperature in a dose-dependent manner. Pretreatment with cyclooxygenase-2 (COX-2)-selective inhibitor significantly suppressed TGF-β-induced fever. COX-2 is known as one of the rate-limiting enzymes of the PGE2 synthesis pathway, suggesting that fever induced by TGF-β is COX-2 and PGE2 dependent. TGF-β increased PGE2 levels in cerebrospinal fluid and increased the expression of COX-2 in the brain. Double immunostaining of COX-2 and von Willebrand factor (vWF, an endothelial cell marker) revealed that COX-2-expressing cells were mainly endothelial cells. Although not all COX-2-immunoreactive cells express TGF-β receptor, some COX-2-immunoreactive cells express activin receptor-like kinase-1 (ALK-1, an endothelial cell-specific TGF-β receptor), suggesting that TGF-β directly or indirectly acts on endothelial cells to induce COX-2 expression. These findings suggest a novel function of TGF-β as a proinflammatory cytokine in the central nervous system.

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