RESUMO
Glucocorticoids represent the mainstay of therapy for a broad spectrum of immune-mediated inflammatory diseases. However, the molecular mechanisms underlying their anti-inflammatory mode of action have remained incompletely understood1. Here we show that the anti-inflammatory properties of glucocorticoids involve reprogramming of the mitochondrial metabolism of macrophages, resulting in increased and sustained production of the anti-inflammatory metabolite itaconate and consequent inhibition of the inflammatory response. The glucocorticoid receptor interacts with parts of the pyruvate dehydrogenase complex whereby glucocorticoids provoke an increase in activity and enable an accelerated and paradoxical flux of the tricarboxylic acid (TCA) cycle in otherwise pro-inflammatory macrophages. This glucocorticoid-mediated rewiring of mitochondrial metabolism potentiates TCA-cycle-dependent production of itaconate throughout the inflammatory response, thereby interfering with the production of pro-inflammatory cytokines. By contrast, artificial blocking of the TCA cycle or genetic deficiency in aconitate decarboxylase 1, the rate-limiting enzyme of itaconate synthesis, interferes with the anti-inflammatory effects of glucocorticoids and, accordingly, abrogates their beneficial effects during a diverse range of preclinical models of immune-mediated inflammatory diseases. Our findings provide important insights into the anti-inflammatory properties of glucocorticoids and have substantial implications for the design of new classes of anti-inflammatory drugs.
Assuntos
Anti-Inflamatórios , Glucocorticoides , Inflamação , Macrófagos , Mitocôndrias , Succinatos , Animais , Feminino , Humanos , Masculino , Camundongos , Anti-Inflamatórios/farmacologia , Carboxiliases/metabolismo , Carboxiliases/antagonistas & inibidores , Ciclo do Ácido Cítrico/efeitos dos fármacos , Ciclo do Ácido Cítrico/genética , Citocinas/imunologia , Citocinas/metabolismo , Glucocorticoides/farmacologia , Glucocorticoides/metabolismo , Hidroliases/deficiência , Hidroliases/genética , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/metabolismo , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Mitocôndrias/efeitos dos fármacos , Complexo Piruvato Desidrogenase/metabolismo , Receptores de Glucocorticoides/metabolismo , Succinatos/metabolismo , Ativação Enzimática/efeitos dos fármacosRESUMO
OBJECTIVES: TWIST1 is a member of the class B of basic helix-loop-helix transcription factors that regulates cell lineage determination and differentiation and has been implicated in epithelial-to-mesenchymal transition. Here, we aimed to investigate the role of TWIST1 for the activation of resident fibroblasts in systemic sclerosis (SSc). METHODS: The expression of Twist1 in fibroblasts was modulated by forced overexpression or siRNA-mediated knockdown. Interaction of Twist1, E12 and inhibitor Of differentiation (Id) was analysed by co-immunoprecipitation. The role of Twist1 in vivo was evaluated using inducible, conditional knockout mice with either ubiquitous or fibroblast-specific depletion of Twist1. Mice were either challenged with bleomycin or overexpressing a constitutively active transforming growth factor (TGF)ß receptor I. RESULT: The expression of TWIST1 was increased in fibroblasts in fibrotic human and murine skin in a TGFß/SMAD3-dependent manner. TWIST1 in turn enhanced TGFß-induced fibroblast activation in a p38-dependent manner. The stimulatory effects of TWIST1 on resident fibroblasts were mediated by TWIST1 homodimers. TGFß promotes the formation of TWIST1 homodimers by upregulation of TWIST1 and by induction of inhibitor of DNA-binding proteins, which have high affinity for E12/E47 and compete against TWIST1 for E12/E47 binding. Mice with selective depletion of Twist1 in fibroblasts are protected from experimental skin fibrosis in different murine models to a comparable degree as mice with ubiquitous depletion of Twist1. CONCLUSIONS: Our data identify TWIST1 as a central pro-fibrotic factor in SSc, which facilitates fibroblast activation by amplifying TGFß signalling. Targeting of TWIST1 may thus be a novel approach to normalise aberrant TGFß signalling in SSc.
Assuntos
Fibroblastos/metabolismo , Proteínas Nucleares/fisiologia , Escleroderma Sistêmico/metabolismo , Proteína 1 Relacionada a Twist/fisiologia , Animais , Estudos de Casos e Controles , Feminino , Fibroblastos/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/fisiologia , Técnicas de Silenciamento de Genes , Humanos , Masculino , Camundongos Knockout , Proteínas Nucleares/biossíntese , Proteínas Nucleares/deficiência , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Multimerização Proteica/fisiologia , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Escleroderma Sistêmico/patologia , Transdução de Sinais/fisiologia , Pele/patologia , Fator de Crescimento Transformador beta/farmacologia , Proteína 1 Relacionada a Twist/biossíntese , Proteína 1 Relacionada a Twist/deficiência , Proteína 1 Relacionada a Twist/genética , Proteína 1 Relacionada a Twist/metabolismoRESUMO
BACKGROUND: Sirt1 is a member of the sirtuin family of proteins. Sirt1 is a class III histone deacetylase with important regulatory roles in transcription, cellular differentiation, proliferation and metabolism. As aberrant epigenetic modifications have been linked to the pathogenesis of systemic sclerosis (SSc), we aimed to investigate the role of Sirt1 in fibroblast activation. METHODS: Sirt1 expression was analysed by real-time PCR, western blot and immunohistochemistry. Sirt1 signalling was modulated with the Sirt1 agonist resveratrol and by fibroblast-specific knockout. The role of Sirt1 was evaluated in bleomycin-induced skin fibrosis and in mice overexpressing a constitutively active transforming growth fac-tor-ß (TGF-ß) receptor I (TBRIact). RESULTS: The expression of Sirt1 was decreased in patients with SSc and in experimental fibrosis in a TGF-ß-dependent manner. Activation of Sirt1 potentiated the profibrotic effects of TGF-ß with increased Smad reporter activity, elevated transcription of TGF-ß target genes and enhanced release of collagen. In contrast, knockdown of Sirt1 inhibited TGF-ß/SMAD signalling and reduced release of collagen in fibroblasts. Consistently, mice with fibroblast-specific knockdown of Sirt1 were less susceptible to bleomycin- or TBRIact-induced fibrosis. CONCLUSIONS: We identified Sirt1 as a crucial regulator of TGF-ß/Smad signalling in SSc. Although Sirt1 is downregulated, this decrease is not sufficient to counterbalance the excessive activation of TGF-ß signalling in SSc. However, augmentation of this endogenous regulatory mechanism, for example, by knockdown of Sirt1, can effectively inhibit TGF-ß signalling and exerts potent antifibrotic effects. Sirt1 may thus be a key regulator of fibroblast activation in SSc.
Assuntos
Fibroblastos/metabolismo , Escleroderma Sistêmico/metabolismo , Sirtuína 1/fisiologia , Pele/patologia , Fator de Crescimento Transformador beta/fisiologia , Adulto , Idoso , Animais , Bleomicina , Estudos de Casos e Controles , Células Cultivadas , Modelos Animais de Doenças , Regulação para Baixo/fisiologia , Feminino , Fibrose , Humanos , Masculino , Camundongos Knockout , Pessoa de Meia-Idade , Escleroderma Sistêmico/patologia , Transdução de Sinais/fisiologia , Pele/metabolismoRESUMO
BACKGROUND: Activating transcription factor 3 (ATF3), a member of the ATF/cAMP-responsive element binding (CREB) family of transcription factors, regulates cellular response to stress including oxidative stress. The aim of this study was to analyse the role of ATF3 in fibroblast activation in systemic sclerosis (SSc). METHODS: ATF3 was analysed by reverse transcription quantitative PCR, western blot and immunohistochemistry. ATF3 knockout fibroblasts and mice were used to study the functional role of ATF3. Knockdown experiments, reporter assays and coimmunoprecipitation were performed to study the effects of ATF3 on Smad and activation protein 1 (AP-1) signalling. The role of c-Jun was analysed by costaining, specific inactivation and coimmunoprecipitation. RESULTS: Transforming growth factor-ß (TGFß) upregulates the expression of ATF3 in SSc fibroblasts. ATF3-deficient fibroblasts were less sensitive to TGFß, whereas ectopic expression of ATF3 enhanced the profibrotic effects of TGFß. Mechanistically, ATF3 interacts with Smad3 directly on stimulation with TGFß and regulates Smad activity in a c-Jun-dependent manner. Knockout of ATF3 protected mice from bleomycin-induced fibrosis and fibrosis induced by overexpression of a constitutively active TGFß receptor I. Reporter assays and analyses of the expression of Smad target genes demonstrated that binding of ATF3 regulates the transcriptional activity of Smad3. CONCLUSIONS: We demonstrate for the first time a key role for ATF3 in fibrosis. Knockout of the ATF3 gene reduced the stimulatory effect of TGFß on fibroblasts by interfering with canonical Smad signalling and protected the mice from experimental fibrosis in two different models. ATF3 might thus be a candidate for molecular targeted therapies for SSc.
Assuntos
Fator 3 Ativador da Transcrição/genética , Fibroblastos/metabolismo , Escleroderma Sistêmico/genética , Proteína Smad3/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Adulto , Idoso , Animais , Western Blotting , Estudos de Casos e Controles , Derme/citologia , Feminino , Fibrose/genética , Imunofluorescência , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Humanos , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Knockout , Pessoa de Meia-Idade , Proteínas Serina-Treonina Quinases , Proteínas Proto-Oncogênicas c-jun/metabolismo , Receptor do Fator de Crescimento Transformador beta Tipo I , Receptores de Fatores de Crescimento Transformadores beta , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Escleroderma Sistêmico/metabolismo , Transdução de Sinais/genética , Fator de Transcrição AP-1/metabolismo , Adulto JovemRESUMO
OBJECTIVES: Tribbles 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). METHODS: The 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. RESULTS: TRB3 expression was increased in fibroblasts of patients with SSc and in murine models of SSc in a transforming growth factor-ß (TGF-ß)/Smad-dependent manner. Overexpression of TRB3 stimulated canonical TGF-ß signalling and induced an activated phenotype in resting fibroblasts. In contrast, knockdown of TRB3 reduced the profibrotic effects of TGF-ß and decreased the collagen synthesis. Moreover, siRNA-mediated knockdown of TRB3 exerted potent antifibrotic effects and ameliorated bleomycin as well as constitutively active TGF-ß receptor I-induced fibrosis with reduced dermal thickening, decreased hydroxyproline content and impaired myofibroblast differentiation. CONCLUSIONS: The present study characterises TRB3 as a novel profibrotic mediator in SSc. TGF-ß induces TRB3, which in turn activates canonical TGF-ß/Smad signalling and stimulates the release of collagen, thereby inducing a positive feedback loop that may contribute to aberrant TGF-ß signalling in SSc.
Assuntos
Proteínas de Ciclo Celular/genética , Fibroblastos/metabolismo , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Repressoras/genética , Escleroderma Sistêmico/genética , Proteína Smad3/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Adulto , Idoso , Animais , Antibióticos Antineoplásicos/toxicidade , Bleomicina/toxicidade , Estudos de Casos e Controles , Proteínas de Ciclo Celular/metabolismo , Células Cultivadas , Colágeno/metabolismo , Derme/citologia , Modelos Animais de Doenças , Feminino , Fibrose/induzido quimicamente , Fibrose/genética , Técnicas de Introdução de Genes , Técnicas de Silenciamento de Genes , Humanos , Imuno-Histoquímica , Masculino , Camundongos , Pessoa de Meia-Idade , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Receptor do Fator de Crescimento Transformador beta Tipo I , Receptores de Fatores de Crescimento Transformadores beta , Proteínas Repressoras/metabolismo , Escleroderma Sistêmico/metabolismo , Transdução de Sinais/genética , Dermatopatias/induzido quimicamente , Dermatopatias/genética , Adulto JovemRESUMO
BACKGROUND: Nintedanib is a tyrosine kinase inhibitor that has recently been shown to slow disease progression in idiopathic pulmonary fibrosis in two replicate phase III clinical trials. The aim of this study was to analyse the antifibrotic effects of nintedanib in preclinical models of systemic sclerosis (SSc) and to provide a scientific background for clinical trials in SSc. METHODS: The effects of nintedanib on migration, proliferation, myofibroblast differentiation and release of extracellular matrix of dermal fibroblasts were analysed by microtitre tetrazolium and scratch assays, stress fibre staining, qPCR and SirCol assays. The antifibrotic effects of nintedanib were evaluated in bleomycin-induced skin fibrosis, in a murine sclerodermatous chronic graft-versus-host disease model and in tight-skin-1 mice. RESULTS: Nintedanib dose-dependently reduced platelet-derived growth factor-induced and transforming growth factor-ß-induced proliferation and migration as well as myofibroblast differentiation and collagen release of dermal fibroblasts from patients with and healthy individuals. Nintedanib also inhibited the endogenous activation of SSc fibroblasts. Nintedanib prevented bleomycin-induced skin fibrosis in a dose-dependent manner and was also effective in the treatment of established fibrosis. Moreover, treatment with nintedanib ameliorated fibrosis in the chronic graft-versus-host disease model and in tight-skin-1 mice in well-tolerated doses. CONCLUSIONS: We demonstrate that nintedanib effectively inhibits the endogenous as well as cytokine-induced activation of SSc fibroblasts and exerts potent antifibrotic effects in different complementary mouse models of SSc. These data have direct translational implications for clinical trials with nintedanib in SSc.
Assuntos
Fibroblastos/efeitos dos fármacos , Indóis/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Escleroderma Sistêmico/tratamento farmacológico , Animais , Bleomicina , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos/métodos , Feminino , Fibroblastos/patologia , Fibroblastos/fisiologia , Fibrose , Doença Enxerto-Hospedeiro/prevenção & controle , Humanos , Indóis/administração & dosagem , Indóis/farmacologia , Masculino , Camundongos Endogâmicos BALB C , Camundongos Mutantes , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/farmacologia , Escleroderma Sistêmico/patologia , Pele/efeitos dos fármacos , Pele/patologiaRESUMO
OBJECTIVES: Stimulators of the soluble guanylate cyclase (sGC) have recently been shown to inhibit transforming growth factor-ß signalling. Here, we aimed to demonstrate that riociguat, the drug candidate for clinical trials in systemic sclerosis (SSc), is effective in experimental fibrosis and to compare its efficacy to that of phosphodiesterase V inhibitors that also increase the intracellular levels of cyclic guanosine monophosphate. METHODS: The antifibrotic effects of riociguat and sildenafil were compared in the tight-skin 1 model, in bleomycin-induced fibrosis and in a model of sclerodermatous chronic graft-versus-host-disease (cGvHD). Doses of 0.1-3â mg/kg twice a day for riociguat and of 3-10â mg/kg twice a day for sildenafil were used. RESULT: Riociguat dose-dependently reduced skin thickening, myofibroblast differentiation and accumulation of collagen with potent antifibrotic effects at 1 and 3â mg/kg. Riociguat also ameliorated fibrosis of the gastrointestinal tract in the cGvHD model. The antifibrotic effects were associated with reduced phosphorylation of extracellular signal-regulated kinases. Sildenafil at doses of 3 and 10â mg/kg exerted mild antifibrotic effects that were significantly less pronounced compared with 1 and 3â mg/kg riociguat. CONCLUSIONS: These data demonstrated potent antifibrotic effects of riociguat on experimental skin and organ fibrosis. These findings suggest a role for riociguat for the treatment of fibrotic diseases, especially for the treatment of SSc. A phase II study with riociguat in patients with SSc is currently starting.
Assuntos
Guanilato Ciclase/efeitos dos fármacos , Pirazóis/farmacologia , Pirimidinas/farmacologia , Pele/patologia , Animais , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Fibrose , Camundongos , Camundongos Endogâmicos , Inibidores da Fosfodiesterase 5/farmacologia , Pirazóis/administração & dosagem , Pirazóis/uso terapêutico , Pirimidinas/administração & dosagem , Pirimidinas/uso terapêutico , Escleroderma Sistêmico/tratamento farmacológico , Citrato de Sildenafila/farmacologiaRESUMO
OBJECTIVES: We have previously described the antifibrotic role of the soluble guanylate cyclase (sGC). The mode of action, however, remained elusive. In the present study, we describe a novel link between sGC signalling and transforming growth factor ß (TGFß) signalling that mediates the antifibrotic effects of the sGC. METHODS: Human fibroblasts and murine sGC knockout fibroblasts were treated with the sGC stimulator BAY 41-2272 or the stable cyclic guanosine monophosphate (cGMP) analogue 8-Bromo-cGMP and stimulated with TGFß. sGC knockout fibroblasts were isolated from sGCI(fl/fl) mice, and recombination was induced by Cre-adenovirus. In vivo, we studied the antifibrotic effects of BAY 41-2272 in mice overexpressing a constitutively active TGF-ß1 receptor. RESULTS: sGC stimulation inhibited TGFß-dependent fibroblast activation and collagen release. sGC knockout fibroblasts confirmed that the sGC is essential for the antifibrotic effects of BAY 41-2272. Furthermore, 8-Bromo-cGMP reduced TGFß-dependent collagen release. While nuclear p-SMAD2 and 3 levels, SMAD reporter activity and transcription of classical TGFß target genes remained unchanged, sGC stimulation blocked the phosphorylation of ERK. In vivo, sGC stimulation inhibited TGFß-driven dermal fibrosis but did not change p-SMAD2 and 3 levels and TGFß target gene expression, confirming that non-canonical TGFß pathways mediate the antifibrotic sGC activity. CONCLUSIONS: We elucidated the antifibrotic mode of action of the sGC that increases cGMP levels, blocks non-canonical TGFß signalling and inhibits experimental fibrosis. Since sGC stimulators have shown excellent efficacy and tolerability in phase 3 clinical trials for pulmonary arterial hypertension, they may be further developed for the simultaneous treatment of fibrosis and vascular disease in systemic sclerosis.
Assuntos
Fibroblastos/patologia , Guanilato Ciclase/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Escleroderma Sistêmico/patologia , Escleroderma Sistêmico/fisiopatologia , Transdução de Sinais/fisiologia , Pele/patologia , Fator de Crescimento Transformador beta/antagonistas & inibidores , Animais , Estudos de Casos e Controles , Células Cultivadas , Colágeno/metabolismo , GMP Cíclico/metabolismo , Modelos Animais de Doenças , Fibroblastos/metabolismo , Fibrose/metabolismo , Fibrose/prevenção & controle , Guanilato Ciclase/deficiência , Humanos , Técnicas In Vitro , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/fisiologia , Camundongos , Camundongos Knockout , Pirazóis/farmacologia , Piridinas/farmacologia , Receptores Citoplasmáticos e Nucleares/agonistas , Receptores Citoplasmáticos e Nucleares/deficiência , Receptores de Fatores de Crescimento Transformadores beta/efeitos dos fármacos , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Escleroderma Sistêmico/metabolismo , Transdução de Sinais/efeitos dos fármacos , Pele/metabolismo , Proteínas Smad/metabolismo , Guanilil Ciclase Solúvel , Fator de Crescimento Transformador beta/metabolismoRESUMO
OBJECTIVES: S100A4 is a calcium binding protein with regulatory functions in cell homeostasis, proliferation and differentiation that has been shown to promote cancer progression and metastasis. In the present study, we evaluated the role of S100A4 in fibroblast activation in systemic sclerosis (SSc). METHODS: The expression of S100A4 was analysed in human samples, murine models of SSc and in cultured fibroblasts by real-time PCR, immunohistochemistry and western blot. The functional role of S100A4 was evaluated using siRNA, overexpression, recombinant protein and S100A4 knockout (S100A4(-/-)) mice. Transforming growth factor ß (TGF-ß) signalling was assessed by reporter assays, staining for phosphorylated Smad2/3 and analyses of target genes. RESULTS: The expression of S100A4 was increased in SSc skin and in experimental fibrosis in a TGF-ß/Smad-dependent manner. Overexpression of S100A4 or stimulation with recombinant S100A4 induced an activated phenotype in resting normal fibroblasts. In contrast, knockdown of S100A4 reduced the pro-fibrotic effects of TGF-ß and decreased the release of collagen. S100A4(-/-) mice were protected from bleomycin-induced skin fibrosis with reduced dermal thickening, decreased hydroxyproline content and lower myofibroblast counts. Deficiency of S100A4 also ameliorated fibrosis in the tight-skin-1 (Tsk-1) mouse model. CONCLUSIONS: We characterised S100A4 as a downstream mediator of the stimulatory effects of TGF-ß on fibroblasts in SSc. TGF-ß induces the expression of S100A4 to stimulate the release of collagen in SSc fibroblasts and induce fibrosis. Since S100A4 is essentially required for the pro-fibrotic effects of TGF-ß and neutralising antibodies against S100A4 are currently evaluated, S100A4 might be a candidate for novel antifibrotic therapies.
Assuntos
Fibroblastos/metabolismo , Proteínas S100/metabolismo , Escleroderma Sistêmico/metabolismo , Pele/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Adulto , Idoso , Animais , Modelos Animais de Doenças , Feminino , Humanos , Masculino , Camundongos , Camundongos Knockout , Pessoa de Meia-Idade , Proteína A4 de Ligação a Cálcio da Família S100 , Proteína Smad2/metabolismo , Proteína Smad3/metabolismo , Adulto JovemRESUMO
BACKGROUND: Vitamin D receptor (VDR) is a member of the nuclear receptor superfamily. Its ligand, 1,25-(OH)2D, is a metabolically active hormone derived from vitamin D3. The levels of vitamin D3 are decreased in patients with systemic sclerosis (SSc). Here, we aimed to analyse the role of VDR signalling in fibrosis. METHODS: VDR expression was analysed in SSc skin, experimental fibrosis and human fibroblasts. VDR signalling was modulated by siRNA and with the selective agonist paricalcitol. The effects of VDR on Smad signalling were analysed by reporter assays, target gene analyses and coimmunoprecipitation. The effects of paricalcitol were evaluated in the models of bleomycin-induced fibrosis and fibrosis induced by overexpression of a constitutively active transforming growth factor-ß (TGF-ß) receptor I (TBRI(CA)). RESULTS: VDR expression was decreased in fibroblasts of SSc patients and murine models of SSc in a TGF-ß-dependent manner. Knockdown of VDR enhanced the sensitivity of fibroblasts towards TGF-ß. In contrast, activation of VDR by paricalcitol reduced the stimulatory effects of TGF-ß on fibroblasts and inhibited collagen release and myofibroblast differentiation. Paricalcitol stimulated the formation of complexes between VDR and phosphorylated Smad3 in fibroblasts to inhibit Smad-dependent transcription. Preventive and therapeutic treatment with paricalcitol exerted potent antifibrotic effects and ameliorated bleomycin- as well as TBRI(CA)-induced fibrosis. CONCLUSIONS: We characterise VDR as a negative regulator of TGF-ß/Smad signalling. Impaired VDR signalling with reduced expression of VDR and decreased levels of its ligand may thus contribute to hyperactive TGF-ß signalling and aberrant fibroblast activation in SSc.
Assuntos
Fibroblastos/metabolismo , Receptores de Calcitriol/metabolismo , Escleroderma Sistêmico/metabolismo , Transdução de Sinais/fisiologia , Pele/metabolismo , Proteínas Smad/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Adulto , Idoso , Animais , Bleomicina/toxicidade , Modelos Animais de Doenças , Ergocalciferóis/farmacologia , Feminino , Fibroblastos/efeitos dos fármacos , Fibrose/induzido quimicamente , Fibrose/metabolismo , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , RNA Interferente Pequeno/metabolismo , Receptores de Calcitriol/agonistas , Transdução de Sinais/efeitos dos fármacos , Pele/efeitos dos fármacos , Pele/patologia , Proteínas Smad/efeitos dos fármacos , Fator de Crescimento Transformador beta/efeitos dos fármacos , Adulto JovemRESUMO
OBJECTIVES: To investigate the role of liver X receptors (LXRs) in experimental skin fibrosis and evaluate their potential as novel antifibrotic targets. METHODS: We studied the role of LXRs in bleomycin-induced skin fibrosis, in the model of sclerodermatous graft-versus-host disease (sclGvHD) and in tight skin-1 (Tsk-1) mice, reflecting different subtypes of fibrotic disease. We examined both LXR isoforms using LXRα-, LXRß- and LXR-α/ß-double-knockout mice. Finally, we investigated the effects of LXRs on fibroblasts and macrophages to establish the antifibrotic mode of action of LXRs. RESULTS: LXR activation by the agonist T0901317 had antifibrotic effects in bleomycin-induced skin fibrosis, in the sclGvHD model and in Tsk-1 mice. The antifibrotic activity of LXRs was particularly prominent in the inflammation-driven bleomycin and sclGvHD models. LXRα-, LXRß- and LXRα/ß-double-knockout mice showed a similar response to bleomycin as wildtype animals. Low levels of the LXR target gene ABCA-1 in the skin of bleomycin-challenged and control mice suggested a low baseline activation of the antifibrotic LXR signalling, which, however, could be specifically activated by T0901317. Fibroblasts were not the direct target cells of LXRs agonists, but LXR activation inhibited fibrosis by interfering with infiltration of macrophages and their release of the pro-fibrotic interleukin-6. CONCLUSIONS: We identified LXRs as novel targets for antifibrotic therapies, a yet unknown aspect of these nuclear receptors. Our data suggest that LXR activation might be particularly effective in patients with inflammatory disease subtypes. Activation of LXRs interfered with the release of interleukin-6 from macrophages and, thus, inhibited fibroblast activation and collagen release.
Assuntos
Fibroblastos/metabolismo , Interleucina-6/metabolismo , Macrófagos/metabolismo , Receptores Nucleares Órfãos/genética , Esclerodermia Difusa/metabolismo , Dermatopatias/metabolismo , Pele/patologia , Animais , Antibióticos Antineoplásicos/toxicidade , Bleomicina/toxicidade , Modelos Animais de Doenças , Fibroblastos/efeitos dos fármacos , Fibrose , Humanos , Hidrocarbonetos Fluorados/farmacologia , Receptores X do Fígado , Macrófagos/efeitos dos fármacos , Camundongos , Camundongos Knockout , Receptores Nucleares Órfãos/agonistas , Receptores Nucleares Órfãos/metabolismo , Pele/efeitos dos fármacos , Dermatopatias/induzido quimicamente , Sulfonamidas/farmacologiaRESUMO
OBJECTIVES: IL-35 is a member of the IL-12 family consisting of p35/IL-12a and EBI3/IL-27b subunits. IL-35 exerts immunomodulatory activities in experimental and human autoimmune inflammatory conditions. Our aim was to assess IL-35 expression in the skin and circulation of SSc patients and to characterize its potential association with SSc-related features. METHODS: Expression of IL-35 in skin and dermal fibroblasts was quantified by quantitative PCR, immunohistochemistry and immunofluorescence. Serum levels of IL-35 (by ELISA), CRP (by turbidimetry), ANA (by immunofluorescence) and autoantibodies of the ENA complex (by immunoblot) were measured in 40 SSc patients. Serum IL-35 was determined in 40 age- and sex-matched healthy controls. RESULTS: IL-35 expression was increased in SSc skin and dermal fibroblasts in a TGF-ß-dependent manner. IL-35 induced an activated phenotype in resting fibroblasts and enhanced the release of collagen. IL-35 serum levels were increased in patients with SSc compared with healthy controls [median 83.9 (interquartile range 45.1-146.1) vs 36.2 (interquartile range 17.2-49.4) pg/ml, P < 0.0001]. Serum IL-35 was negatively correlated with disease duration (r = -0.4339, P = 0.0052). In line with this finding, serum IL-35 was increased in patients with an early SSc pattern on capillaroscopy assessment compared with those with active and late SSc patterns. CONCLUSION: The present study demonstrates overexpression of IL-35 in SSc skin, dermal fibroblasts and serum. TGF-ß induces IL-35, which in turn activates resting fibroblasts and enhances the release of collagen, thereby contributing to aberrant TGF-ß signalling in SSc. Increased serum IL-35 is associated with early, inflammatory stages of SSc.
Assuntos
Interleucinas/biossíntese , Escleroderma Sistêmico/imunologia , Adulto , Idoso , Estudos de Casos e Controles , Células Cultivadas , Colágeno/biossíntese , Feminino , Fibroblastos/imunologia , Humanos , Interleucinas/sangue , Interleucinas/genética , Masculino , Pessoa de Meia-Idade , RNA Mensageiro/genética , Pele/imunologia , Fator de Crescimento Transformador beta/imunologia , Regulação para Cima/imunologiaRESUMO
OBJECTIVES: Targeted therapies for systemic sclerosis (SSc) and other fibrotic diseases are not yet available. We evaluated the efficacy of heat shock protein 90 (Hsp90) inhibition as a novel approach to inhibition of aberrant transforming growth factor (TGF)-ß signalling and for the treatment of fibrosis in preclinical models of SSc. METHODS: Expression of Hsp90 was quantified by quantitative PCR, western blot and immunohistochemistry. The effects of Hsp90 inhibition were analysed in cultured fibroblasts, in bleomycin-induced dermal fibrosis, in tight-skin (Tsk-1) mice and in mice overexpressing a constitutively active TGF-ß receptor I (TßRI). RESULTS: Expression of Hsp90ß was increased in SSc skin and in murine models of SSc in a TGF-ß-dependent manner. Inhibition of Hsp90 by 17-dimethylaminoethylamino-17-demethoxy-geldanamycin (17-DMAG) inhibited canonical TGF-ß signalling and completely prevented the stimulatory effects of TGF-ß on collagen synthesis and myofibroblast differentiation. Treatment with 17-DMAG decreased the activation of canonical TGF-ß signalling in murine models of SSc and exerted potent antifibrotic effects in bleomycin-induced dermal fibrosis, in Tsk-1 mice and in mice overexpressing a constitutively active TßRI. Dermal thickness, number of myofibroblasts and hydroxyproline content were all significantly reduced on treatment with 17-DMAG. No toxic effects were observed with 17-DMAG at antifibrotic doses. CONCLUSIONS: Hsp90 is upregulated in SSc and is critical for TGF-ß signalling. Pharmacological inhibition of Hsp90 effectively blocks the profibrotic effects of TGF-ß in cultured fibroblasts and in different preclinical models of SSc. These results have translational implications, as several Hsp90 inhibitors are in clinical trials for other indications.
Assuntos
Fibroblastos/metabolismo , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Escleroderma Sistêmico/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Adulto , Idoso , Animais , Benzoquinonas/farmacologia , Células Cultivadas , Modelos Animais de Doenças , Feminino , Fibroblastos/efeitos dos fármacos , Fibrose , Proteínas de Choque Térmico HSP90/metabolismo , Humanos , Lactamas Macrocíclicas/farmacologia , Masculino , Camundongos , Camundongos Transgênicos , Pessoa de Meia-Idade , Proteínas Serina-Treonina Quinases/genética , Receptor do Fator de Crescimento Transformador beta Tipo I , Receptores de Fatores de Crescimento Transformadores beta/genética , Escleroderma Sistêmico/prevenção & controle , Transdução de Sinais/efeitos dos fármacos , Pele/efeitos dos fármacos , Pele/metabolismo , Fator de Crescimento Transformador beta/efeitos dos fármacosRESUMO
OBJECTIVES: Activated Wnt signalling with decreased expression of endogenous inhibitors has recently been characterised as a central pathomechanism in systemic sclerosis (SSc). Aberrant epigenetic modifications also contribute to the persistent activation of SSc fibroblasts. We investigated whether increased Wnt signalling and epigenetic changes in SSc are causally linked via promoter hypermethylation-induced silencing of Wnt antagonists. METHODS: The methylation status of endogenous Wnt antagonists in leucocytes and fibroblasts was evaluated by methylation-specific PCR. 5-aza-2'-deoxycytidine was used to inhibit DNA methyltransferases (Dnmts) in cultured fibroblasts and in the mouse model of bleomycin-induced skin fibrosis. Activation of Wnt signalling was assessed by analysing Axin2 mRNA levels and by staining for ß-catenin. RESULTS: The promoters of DKK1 and SFRP1 were hypermethylated in fibroblasts and peripheral blood mononuclear cells of patients with SSc. Promoter hypermethylation resulted in impaired transcription and decreased expression of DKK1 and SFRP1 in SSc. Treatment of SSc fibroblasts or bleomycin-challenged mice with 5-aza prevented promoter methylation-induced silencing and increased the expression of both genes to normal levels. Reactivation of DKK1 and SFRP1 transcription by 5-aza inhibited canonical Wnt signalling in vitro and in vivo and effectively ameliorated experimental fibrosis. CONCLUSIONS: We demonstrate that hypermethylation of the promoters of DKK1 and SFRP1 contributes to aberrant Wnt signalling in SSc and that Dnmt inhibition effectively reduces Wnt signalling. These data provide a novel link between epigenetic alterations and increased Wnt signalling in SSc and also have translational implications because Dnmt inhibitors are already approved for clinical use.
Assuntos
Metilação de DNA/genética , Regulação para Baixo/genética , Fibroblastos/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/genética , Leucócitos Mononucleares/metabolismo , Proteínas de Membrana/genética , Escleroderma Sistêmico/genética , Via de Sinalização Wnt/genética , Adulto , Idoso , Animais , Azacitidina/análogos & derivados , Azacitidina/farmacologia , Estudos de Casos e Controles , DNA (Citosina-5-)-Metiltransferase 1 , DNA (Citosina-5-)-Metiltransferases/antagonistas & inibidores , Metilação de DNA/efeitos dos fármacos , Decitabina , Regulação para Baixo/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Epigênese Genética , Feminino , Fibroblastos/efeitos dos fármacos , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Regiões Promotoras Genéticas/genética , Via de Sinalização Wnt/efeitos dos fármacos , Adulto JovemRESUMO
OBJECTIVES: Canonical as well as non-canonical Wnt signalling pathways have emerged as core pathways of fibrosis. Their profibrotic effects are mediated via distinct intracellular cascades independently of each other. Thus, inhibition of both pathways may have additive antifibrotic effects. Here, we knocked down evenness interrupted (EVI) to simultaneously target for the first time canonical and non-canonical Wnt signalling in experimental fibrosis. METHODS: The antifibrotic effects of siRNA-mediated knockdown of EVI were evaluated in the mouse models of bleomycin-induced skin fibrosis and in fibrosis induced by adenoviral overexpression of a constitutively active TGF-ß receptor I (AdTBRI). RESULTS: Knockdown of EVI decreased the release of canonical and non-canonical Wnt ligands by fibroblasts and reduced the activation of canonical and non-canonical Wnt cascades in experimental fibrosis with decreased accumulation of ß-catenin and phosphorylated JNK and cJun. Inactivation of EVI exerted potent antifibrotic effects and reduced dermal thickening, myofibroblast differentiation and accumulation of collagen in the mouse models of bleomycin-induced and AdTBR-induced fibrosis. CONCLUSIONS: Inhibition of Wnt secretion by knockdown of EVI inhibits canonical and non-canonical Wnt signalling and effectively reduces experimental fibrosis in different preclinical models. Inhibition of Wnt secretion may thus be an interesting approach for the treatment of fibrosis.
Assuntos
Fibroblastos/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Receptores Acoplados a Proteínas G/genética , Escleroderma Sistêmico/prevenção & controle , Pele/patologia , Via de Sinalização Wnt/genética , Animais , Células Cultivadas , Modelos Animais de Doenças , Fibrose , Técnicas de Silenciamento de Genes , Terapia Genética/métodos , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/fisiologia , MAP Quinase Quinase 4/metabolismo , Camundongos , Fosforilação , Proteínas Proto-Oncogênicas c-jun/metabolismo , RNA Interferente Pequeno/genética , Receptores Acoplados a Proteínas G/fisiologia , Escleroderma Sistêmico/genética , Escleroderma Sistêmico/metabolismo , Escleroderma Sistêmico/patologia , Via de Sinalização Wnt/fisiologia , beta Catenina/metabolismoRESUMO
OBJECTIVES: The morphogen pathways Hedgehog, Wnt and Notch are attractive targets for antifibrotic therapies in systemic sclerosis. Interference with stem cell regeneration, however, may complicate the use of morphogen pathway inhibitors. We therefore tested the hypothesis that combination therapies with low doses of Hedgehog, Wnt and Notch inhibitors maybe safe and effective for the treatment of fibrosis. METHODS: Skin fibrosis was induced by bleomycin and by overexpression of a constitutively active TGF-ß receptor type I. Adverse events were assessed by clinical monitoring, pathological evaluation and quantification of Lgr5-positive intestinal stem cells. RESULTS: Inhibition of Hedgehog, Wnt and Notch signalling dose-dependently ameliorated bleomycin-induced and active TGF-ß receptor type I-induced fibrosis. Combination therapies with low doses of Hedgehog/Wnt inhibitors or Hedgehog/Notch inhibitors demonstrated additive antifibrotic effects in preventive as well as in therapeutic regimes. Combination therapies were well tolerated. In contrast with high dose monotherapies, combination therapies did not reduce the number of Lgr5 positive intestinal stem cells. CONCLUSIONS: Combined inhibition of morphogen pathways exerts additive antifibrotic effects. Combination therapies are well tolerated and, in contrast to high dose monotherapies, may not impair stem cell renewal. Combined targeting of morphogen pathways may thus help to overcome dose-limiting toxicity of Hedgehog, Wnt and Notch signalling.
Assuntos
Fibrose/tratamento farmacológico , Proteínas Hedgehog/antagonistas & inibidores , Receptores Notch/antagonistas & inibidores , Escleroderma Sistêmico/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos , Pele/efeitos dos fármacos , Proteínas Wnt/antagonistas & inibidores , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Animais , Bleomicina , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Modelos Animais de Doenças , Quimioterapia Combinada , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Transgênicos , Proteínas Serina-Treonina Quinases/genética , Pirimidinonas/farmacologia , Receptor do Fator de Crescimento Transformador beta Tipo I , Receptores de Fatores de Crescimento Transformadores beta/genética , Alcaloides de Veratrum/farmacologia , Via de Sinalização Wnt/efeitos dos fármacosRESUMO
Chronic graft-versus-host disease (cGVHD) is a prognosis limiting complication of allogeneic stem cell transplantation. The molecular mechanisms underlying cGVHD are incompletely understood, and targeted therapies are not yet established for clinical use. Here we examined the role of the hedgehog pathway in sclerodermatous cGVHD. Hedgehog signaling was activated in human and murine cGVHD with increased expression of sonic hedgehog and accumulation of the transcription factors Gli-1 and Gli-2. Treatment with LDE223, a highly selective small-molecule antagonist of the hedgehog coreceptor Smoothened (Smo), abrogated the activation of hedgehog signaling and protected against experimental cGVHD. Preventive therapy with LDE223 almost completely impeded the development of clinical and histologic features of sclerodermatous cGVHD. Treatment with LDE223 was also effective, when initiated after the onset of clinical manifestations of cGVHD. Hedgehog signaling stimulated the release of collagen from cultured fibroblasts but did not affect leukocyte influx in murine cGVHD, suggesting direct, leukocyte-independent stimulatory effects on fibroblasts as the pathomechanism of hedgehog signaling in cGVHD. Considering the high morbidity of cGVHD, the current lack of efficient molecular therapies for clinical use, and the availability of well-tolerated inhibitors of Smo, targeting hedgehog signaling might be a novel strategy for clinical trials in cGVHD.
Assuntos
Compostos de Bifenilo/uso terapêutico , Modelos Animais de Doenças , Doença Enxerto-Hospedeiro/prevenção & controle , Proteínas Hedgehog/antagonistas & inibidores , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Escleroderma Sistêmico/prevenção & controle , Animais , Transplante de Medula Óssea , Doença Crônica , Colágeno/metabolismo , Feminino , Fibroblastos/efeitos dos fármacos , Fibroblastos/patologia , Doença Enxerto-Hospedeiro/metabolismo , Doença Enxerto-Hospedeiro/patologia , Proteínas Hedgehog/genética , Proteínas Hedgehog/metabolismo , Humanos , Técnicas Imunoenzimáticas , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase em Tempo Real , Receptores Acoplados a Proteínas G/metabolismo , Escleroderma Sistêmico/metabolismo , Escleroderma Sistêmico/patologia , Receptor SmoothenedRESUMO
OBJECTIVES: Epigenetic modifications such as DNA methylation and histone acetylation have been implicated in the pathogenesis of systemic sclerosis. However, histone methylation has not been investigated so far. We therefore aimed to evaluate the role of the trimethylation of histone H3 on lysine 27 (H3K27me3) on fibroblast activation and fibrosis. METHODS: H3K27me3 was inhibited by 3-deazaneplanocin A (DZNep) in cultured fibroblasts and in two murine models of dermal fibrosis. Fibrosis was analysed by assessment of the dermal thickening, determination of the hydroxyproline content and by quantification of the numbers of myofibroblasts. The expression of fos-related antigen 2 (fra-2) was assessed by real-time PCR, western blot and immunohistochemistry and modulated by siRNA. RESULTS: Inhibition of H3K27me3 stimulated the release of collagen in cultured fibroblasts in a time and dose-dependent manner. Treatment with DZNep exacerbated fibrosis induced by bleomycin or by overexpression of a constitutively active transforming growth factor ß receptor type I. Moreover, treatment with DZNep alone was sufficient to induce fibrosis. Inhibition of H3K27me3 induced the expression of the profibrotic transcription factor fra-2 in vitro and in vivo. Knockdown of fra-2 completely prevented the profibrotic effects of DZNep. CONCLUSIONS: These data demonstrate a novel role of H3 Lys27 histone methylation in fibrosis. In contrast to other epigenetic modifications such as DNA methylation and histone acetylation, H3 Lys27 histone methylation acts as a negative regulator of fibroblast activation in vitro and in vivo by repressing the expression of fra-2.
Assuntos
Fibroblastos/enzimologia , Histonas/metabolismo , Histona Desmetilases com o Domínio Jumonji/metabolismo , Esclerodermia Difusa/metabolismo , Esclerodermia Difusa/patologia , Adulto , Animais , Antibióticos Antineoplásicos/farmacologia , Bleomicina/farmacologia , Células Cultivadas , Colágeno/metabolismo , Metilação de DNA/efeitos dos fármacos , Metilação de DNA/fisiologia , Derme/patologia , Modelos Animais de Doenças , Inibidores Enzimáticos/farmacologia , Epigênese Genética/efeitos dos fármacos , Epigênese Genética/fisiologia , Fibroblastos/patologia , Fibrose/induzido quimicamente , Fibrose/metabolismo , Fibrose/patologia , Antígeno 2 Relacionado a Fos/metabolismo , Humanos , Histona Desmetilases com o Domínio Jumonji/antagonistas & inibidores , Masculino , Camundongos , Camundongos Endogâmicos DBA , Pessoa de Meia-Idade , Esclerodermia Difusa/induzido quimicamente , Adulto JovemRESUMO
BACKGROUND AND OBJECTIVES: Fibrosis is a major socioeconomic burden, but effective antifibrotic therapies are not available in the clinical routine. There is growing evidence for a central role of Wnt signalling in fibrotic diseases such as systemic sclerosis, and we therefore evaluated the translational potential of pharmacological Wnt inhibition in experimental dermal fibrosis. METHODS: We examined the antifibrotic effects of PKF118-310 and ICG-001, two novel inhibitors of downstream canonical Wnt signalling, in the models of prevention and treatment of bleomycin-induced dermal fibrosis as well as in experimental dermal fibrosis induced by adenoviral overexpression of a constitutively active transforming growth factor (TGF)-ß receptor I. RESULTS: PKF118-310 and ICG-001 were well tolerated throughout all experiments. Both therapeutic approaches showed antifibrotic effects in preventing and reversing bleomycin-induced dermal fibrosis as measured by skin thickness, hydroxyproline content and myofibroblast counts. PKF118-310 and ICG-001 were effective in inhibiting TGF-ß receptor I-driven fibrosis as assessed by the same outcome measures. CONCLUSIONS: Blockade of canonical Wnt signalling by PKF118-310 and ICG-001 showed antifibrotic effects in different models of skin fibrosis. Both therapies were well tolerated. Although further experimental evidence for efficacy and tolerability is necessary, inhibition of canonical Wnt signalling is a promising treatment approach for fibrosis.
Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/uso terapêutico , Pirimidinonas/uso terapêutico , Dermatopatias/prevenção & controle , Pele/patologia , Triazinas/uso terapêutico , Via de Sinalização Wnt/efeitos dos fármacos , Animais , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Modelos Animais de Doenças , Fibrose , Camundongos , Camundongos Endogâmicos DBA , Pirimidinonas/farmacologia , Escleroderma Sistêmico , Transdução de Sinais/efeitos dos fármacos , Dermatopatias/tratamento farmacológico , Dermatopatias/patologia , Resultado do Tratamento , Triazinas/farmacologiaRESUMO
OBJECTIVES: Canonical Wnt signalling has recently emerged as a key mediator of fibroblast activation and tissue fibrosis in systemic sclerosis. Here, we investigated tankyrases as novel molecular targets for inhibition of canonical Wnt signalling in fibrotic diseases. METHODS: The antifibrotic effects of the tankyrase inhibitor XAV-939 or of siRNA-mediated knockdown of tankyrases were evaluated in the mouse models of bleomycin-induced dermal fibrosis and in experimental fibrosis induced by adenoviral overexpression of a constitutively active TGF-ß receptor I (Ad-TBRI). RESULTS: Inactivation of tankyrases prevented the activation of canonical Wnt signalling in experimental fibrosis and reduced the nuclear accumulation of ß-catenin and the mRNA levels of the target gene c-myc. Treatment with XAV-939 or siRNA-mediated knockdown of tankyrases in the skin effectively reduced bleomycin-induced dermal thickening, differentiation of resting fibroblasts into myofibroblasts and accumulation of collagen. Potent antifibrotic effects were also observed in Ad-TBRI driven skin fibrosis. Inhibition of tankyrases was not limited by local or systemic toxicity. CONCLUSIONS: Inactivation of tankyrases effectively abrogated the activation of canonical Wnt signalling and demonstrated potent antifibrotic effects in well-tolerated doses. Thus, tankyrases might be candidates for targeted therapies in fibrotic diseases.