UVA1 irradiation attenuates collagen production via Ficz/AhR/MAPK signaling activation in scleroderma.

Scleroderma is an autoimmune disease mainly characterized by progressive fibrosis of the skin. There are two types of scleroderma, namely localized scleroderma (LS) and systemic sclerosis (SSc); skin lesions in both types of scleroderma are histologically identical. Progressive skin sclerosis induces psychological and ecological burden for scleroderma patients. However, there is no effective treatment for scleroderma due to its unclear etiology. Aryl hydrocarbon receptor (AhR) is recognized as an environmental chemical effector that can respond to ultraviolet radiation, which has been demonstrated to participate in the pathogenesis of SSc in our previous study. In this study, we verify whether the anti-fibrosis effect of ultraviolet A1 (UVA1) phototherapy could be partially induced through Ficz/AhR/MAPK signaling activation for fibrotic lesions in both SSc and LS patients. This is the first study to show the association between the AhR pathway and the anti-fibrotic mechanism of UVA1 phototherapy, which provides additional evidence of the role of AhR in the fibrotic mechanism of systemic scleroderma from different perspectives. Ficz and other AhR agonists may replace UVA1 phototherapy as anti-fibrotic agents in scleroderma.

Wenyang Huazhuo Tongluo formula alleviates pulmonary vascular injury and downregulates HIF-1α in bleomycin-induced systemic sclerosis mouse model.

BACKGROUND: Vascular damage, autoimmune abnormalities, and fibrosis are the three pathological features of systemic sclerosis (SSc).However, pulmonary vascular damage is the main factor affecting the progression and prognosis of SSc. The main purpose of this study was to explore the molecular mechanism of Wenyang Huazhuo Tongluo Formula in alleviating pulmonary vascular injury in bleomycin-induced SSc mouse model. METHODS: Masson staining and H&E staining were used to analyze the degree of pulmonary vascular fibrosis and the infiltration of leukocyte cells in lung tissue ofbleomycin-induced SSc mouse models treated with saline (BLM group), Wenyang Huazhuo Tongluo Formula (WYHZTL group) and HIF-1α inhibitor KC7F2 (KC7F2 group). Blood vessel exudation was determined by analyzing the cell number and albumin concentration in bronchoalveolar lavage fluid using a cell counter and ELISA assay, respectively. The degree of vascular injury was assessed by measuring the expression levels of vWF, E-selectin, ICAM-1, VCAM-1, VE-cadherin and claudin-5 in serum and pulmonary vascular endothelial cells using ELISA and immunofluorescence staining. Finally, the effect of Wenyang Huazhuo Tongluo Formula on the expression of HIF-1α was detected using immunofluorescence staining. RESULTS: Wenyang Huazhuo Tongluo Formula and KC7F2 significantly inhibited bleomycin-induced pulmonary vascular fibrosis and the level of perivascular inflammatory cell infiltration. The number of cells and the concentration of albumin were significantly reduced in the bronchoalveolar lavage fluid of the WYHZTL group and KC7F2 group compared with the BLM group. In addition, treatment with Wenyang Huazhuo Tongluo Formula and KC7F2 significantly downregulated the expression levels of vWF, E-selectin, ICAM-1, VCAM-1 and HIF-1α, but upregulated the expression of VE-cadherin and claudin-5 in serum and pulmonary vascular endothelial cells, compared with treatment with saline. CONCLUSIONS: This study reveals that Wenyang Huazhuo Tongluo Formula plays a new role in the treatment of SSc by alleviating pulmonary vascular damage. Furthermore, we found that Wenyang Huazhuo Tongluo Formula alleviates pulmonary vascular injury and inhibits HIF-1α expression.

Questions raised by a case of adult-onset linear nodular scleroderma.

Morphea presenting clinically with nodular or keloidal skin changes is extremely rare. Nodular scleroderma or keloidal morphea presenting in a linear distribution is even more uncommon. We present an otherwise healthy young woman with unilateral, linear, nodular scleroderma and review the somewhat confounding earlier literature in this area. To date, this young woman's skin changes have proven refractory to oral hydroxychloroquine and ultraviolet A1 phototherapy. Several aspects of this case including the patient's family history of Raynaud disease, her nodular sclerodermatous skin lesions, and the presence of U1RNP autoantibodies raised concern about her management with respect to future risk of developing systemic sclerosis.

Frontiers in translational systemic sclerosis research: A focus on the unmet 'cutaneous' clinical needs (Viewpoint).

This viewpoint considers four cutaneous unmet clinical needs of patients with systemic sclerosis (SSc), namely the rapidly progressive skin thickening (scleroderma) which occurs early on in diffuse cutaneous disease; digital (finger and toe) ulcers; calcinosis; and cutaneous telangiectases. All four problems cause pain, disability and/or disfigurement, all impact on quality of life, and for each, we require effective treatments. For each unmet need, we give a brief description of the clinical problem (including clinical burden), pathophysiology and current treatment, followed by a personal viewpoint of the key questions which research must address. For the painful, debilitating skin thickening of early diffuse cutaneous SSc, studies are required to decide whether corticosteroids are effective and safe (current opinion is divided) and whether phototherapy approaches have a role. Also, we need to develop and validate reliable outcome measures for clinical trials of promising new therapies: these could be composite indices, novel non-invasive imaging methods and patient-reported outcome measures, possibly in combination as they provide complementary information. For digital ulcers, again we require validated outcome measures for clinical trials. We also need to explore local (including topical) treatments, which are free from systemic adverse effects, and preventative strategies for high-risk patients. For calcinosis, we need to better understand pathophysiology, to validate outcome measures and to develop topical treatments. For telangiectases, we need to "use" these highly accessible lesions to help unravel the vascular pathophysiology of SSc and explore their different properties as potential biomarkers.

The α7 Nicotinic Acetylcholine Receptor: A Promising Target for the Treatment of Fibrotic Skin Disorders.

Targeting neuroendocrine receptors can be considered as another interesting approach to treating fibrotic disorders. Previously, we could demonstrate that tropisetron, a classical serotonin receptor blocker, can modulate collagen synthesis and acts in vitro through the α7 nicotinic acetylcholine receptor (α7nAchR). Here, we used a pharmacologic approach with specific α7nAchR agonists to validate this hypothesis. PHA-543613, an α7nAchR-specific agonist, not only prevented but also reversed established skin fibrosis of mice injected with bleomycin. Interestingly, agonistic stimulation of α7nAchR also attenuated experimental skin fibrosis in the non-inflammation driven adenovirus coding for TGFß receptor Iact mouse model, indicating fibroblast-mediated and not only anti-inflammatory effects of such agents. The fibroblast-mediated effects were confirmed in vitro using human dermal fibroblasts, in which the α7nAchR-specific agonists strongly reduced the impact of TGFß1-mediated expression on collagen and myofibroblast marker expression. These actions were linked to modulation of the redox-sensitive transcription factor JunB and impairment of the mitochondrial respiratory system. Our results indicate that pharmacologic stimulation of the α7nAchR could be a promising target for treatment of patients with skin fibrotic diseases. Moreover, our results suggest a mechanistic axis of collagen synthesis regulation through the mitochondrial respiratory system.

Celastrol is a novel selective agonist of cannabinoid receptor 2 with anti-inflammatory and anti-fibrotic activity in a mouse model of systemic sclerosis.

BACKGROUND: Increasing evidence indicated that the cannabinoid receptors were involved in the pathogenesis of organ fibrogenesis. PURPOSE: The purpose of this study was to discover novel cannabinoid receptor 2 (CB2) agonist and assess the potential of CB2 activation in treating systemic sclerosis. METHODS: A gaussia princeps luciferase-based split luciferase complementation assay (SLCA) was developed for detection of the interaction between CB2 and ß-arrestin2. A library of 366 natural products was then screened as potential CB2 agonist using SLCA approach. Several GPCR functional assays, including HTRF-based cAMP assay and calcium mobilization were also utilized to evaluated CB2 activation. Bleomycin-induced experimental systemic sclerosis was used to assess the in vivo anti-fibrotic effects. Dermal thickness and collagen content were evaluated via H&E and sirius red staining. RESULTS: Celastrol was identified as a new agonist of CB2 by using SLCA. Furthermore, celastrol triggers several CB2-mediated downstream signaling pathways, including calcium mobilization, inhibition of cAMP accumulation, and receptor desensitization in a dose-dependent manner, and it has a moderate selectivity on CB1. In addition, celastrol exhibited the anti-inflammatory properties on lipopolysaccharide (LPS) treated murine Raw 264.7 macrophages and primary macrophages. Finally, we found that celastrol exerts anti-fibrotic effects in the bleomycin-induced systemic sclerosis mouse model accompanied by reduced inflammatory conditions. CONCLUSION: Taken together, celastrol is identified a novel selective CB2 agonist using a new developed arrestin-based SLCA, and CB2 activation by celastrol reduces the inflammatory response, and prevents the development of dermal fibrosis in bleomycin-induced systemic sclerosis mouse model.

Large Variability of Frequency and Type of Physical Therapy in Patients in the German Network for Systemic Sclerosis.

OBJECTIVE: To determine the type and frequency of physical therapy (PT) prescribed by physicians for patients in the registry of the German Network for Systemic Sclerosis. METHODS: The data for 4,252 patients were analyzed using descriptive statistics, chi-square tests, and odds ratios (ORs). RESULTS: Overall, 37.4% of patients (1,590 of 4,252) received PT at the end of a yearly follow-up. The most frequently used type of PT was lymphatic drainage (n = 1,061, 36.8%), followed by exercise therapy (n = 1,047, 36.3%) and heat therapy (n = 689, 23.9%). More than three-fourths of treated patients (82%) received 1 or 2 different forms of PT simultaneously. The prescription of PT was associated with the extent of skin fibrosis as measured by the modified Rodnan skin thickness score (<10 [41.8% of patients], 11-20 [55.8% of patients], and >21 [63.9% of patients]; P < 0.001). Patients with musculoskeletal involvement (e.g., arthritis, muscle weakness, joint contractures, tendon friction rubs) had a higher chance of receiving PT than patients without these symptoms, with corresponding ORs ranging from 1.96 (95% confidence interval [95% CI] 1.69-2.28) for joint contractures to 3.83 (95% CI 2.89-5.08) for arthritis. When comparing the type of PT prescription across the initial and all follow-up visits from 2003 to 2017, significant alterations with a decreasing frequency of patients receiving PT could be observed (P = 0.001). CONCLUSION: To our knowledge, this is the first study reporting the use of PT in patients with systemic sclerosis (SSc) in a large cohort. Although SSc is characterized by considerable disability and restriction of motion, <40% of patients received PT.

COA-Cl prevented TGF-ß1-induced CTGF expression by Akt dephosphorylation in normal human dermal fibroblasts, and it attenuated skin fibrosis in mice models of systemic sclerosis.

BACKGROUND: Systemic sclerosis (SSc) is characterized by fibrosis of the skin and internal organs. Although transforming growth factor (TGF)-ß1-induced connective tissue growth factor (CTGF/CCN2) expression has been presented in SSc fibrosis, the therapeutic potential of targeting CTGF in SSc has not been fully explored. COA-Cl is a novel nucleic acid analog, which is reported to have pleiotropic beneficial biologic effects. OBJECTIVE: We examine the effects of COA-Cl on TGF-ß1-induced CTGF expression in normal human dermal fibroblast (NHDF). We also examined the effects of COA-Cl on CTGF expression in a mouse SSc model of angiotensin II (Ang II)-induced skin fibrosis. METHODS: NHDF was cultured for in vitro experiments. For in vivo experiments, C57BL/6J mice were treated with Ang II for 14 days by subcutaneous osmotic pump. Quantitative real-time polymerase chain reaction, western blot analysis, immunohistochemical staining and immunofluorescence staining were performed to examine the expression levels of CTGF and phosphorylation levels of Smad2/3, ERK1/2 and Akt. RESULTS: COA-Cl attenuated the TGF-ß1-induced expression of both CTGF mRNA and protein in NHDF. Although COA-Cl did not alter the TGF-ß1-induced phosphorylation of Smad2/3 or ERK1/2, it reduced the TGF-ß1-induced phosphorylation levels of Akt in NHDF. Notably, COA-Cl dephosphorylated the Akt of lysates of TGF-ß1-treated NHDF. COA-Cl reduced the levels of CTGF mRNA, CTGF protein, dermal thickness, collagen content and Akt phosphorylation in the skin of mice SSc model. CONCLUSION: These results imply that the inhibition of TGF-ß1-induced CTGF expression by COA-Cl may be a therapeutic approach for SSc.

Challenges in the diagnosis and treatment of disabling pansclerotic morphea of childhood: case-based review.

Disabling pansclerotic morphea of childhood (DPMC) is a rare subtype of juvenile localized scleroderma (JLS) characterized by pansclerosis mainly affecting children under the age of 14. This aggressive disease has a poor prognosis due to the rapid progression of deep musculoskeletal atrophy resulting in cutaneous ulceration and severe joint contractures. We describe the challenges in treating a previously well 5-year-old male who has refractory symptoms of DPMC. Over the 29 months, since his initial presentation, we trialed over ten therapies. There was subjective improvement with prednisolone and mycophenolate mofetil (MMF). However, other therapies including biologics and tyrosine kinase inhibitors (TKI) were ineffective. The patient has been referred for hematopoietic stem cell transplant given ongoing disease progression. We conducted a literature search focusing on English articles with keywords including DPMC. Publications with limited information or describing cases aged 20 and above were excluded. Thirty-seven case reports were identified and the reported treatments were evaluated. Methotrexate and corticosteroids have been the most commonly utilized. MMF has been anecdotally effective. Biologics, TKI, and Janus kinase inhibitors lack evidence in DPMC, but have had demonstrated efficacy in similar pathologies including systemic sclerosis, and, thus, have been used for DPMC. Phototherapy has been documented to be reducing skin thickness and stiffness of plaques. Eventually, most children require multi-modal and high-dose immunosuppressive therapies to reduce the inflammation inflicted by the disease. Long-term antibiotics and nutritional support are important in the ongoing care of these patients.

Mandibular resorption and vocal cord paralysis: a catastrophic form of systemic sclerosis.

Sudden respiratory distress in association with severe weight loss are unusual features of systemic sclerosis (SSc). We report the case of a 56-year-old Caucasian woman with a 9-year history of a diffuse form of SSc who presented with acute stridor due to vocal cord paralysis and required an emergency tracheostomy. She had sought medical attention only after 4 years of disease onset, presenting with a mask-like face, diffuse skin thickening, acro-osteolysis and severe interstitial lung disease. Even though skin tightness improved after immunosuppressive treatment, several spontaneous facial fractures and episodes of dysphagia and choking occurred in the years that followed. At the time of stridor, she was severely malnourished and a percutaneous endoscopic gastrostomy was required for feeding. Permanent vocal cord damage in combination with severe loco-regional bone resorption resulted in severe disability and impaired nutrition. We hereby highlight the features of SSc for which therapy remains challenging.

Salvianolic acid B attenuates experimental skin fibrosis of systemic sclerosis.

Systemic sclerosis (SSc) is a connective tissue disease characterized mainly by fibrosis of skin and internal organs. Our previous study has shown that salvianolic acid B (SAB), a bioactive component extracted from Salvia miltiorrhiza (SM), was one of the essential ingredients in the traditional Chinese medicine Yiqihuoxue formula, which has been used to treat SSc-related dermal and pulmonary fibrosis. The aim of the present study was to evaluate the effect of SAB on skin fibrosis and explore its underlying anti-fibrotic mechanism. We found that SAB was capable of alleviating skin fibrosis in a bleomycin-induced SSc mouse model, alleviating skin thickness and reducing collagen deposition. in vitro studies indicated that SAB reduced SSc skin fibroblast proliferation and downregulated extracellular matrix gene transcription and collagen protein expression. TGF-ß/SMAD and MAPK/ERK pathway activation were also shown to be suppressed in SAB treated fibroblasts. Moreover, RNA-seq revealed that the anti-fibrotic effect of SAB might be related to antioxidant activity, the cell cycle, and the p53 signaling pathway. Taken together, our results suggest that SAB has the ability to alleviate SSc-related skin fibrosis both in vivo and in vitro.

Diagnostic criteria, severity classification and guidelines of localized scleroderma.

We established diagnostic criteria and severity classification of localized scleroderma because there is no established diagnostic criteria or widely accepted severity classification of the disease. Also, there has been no clinical guideline for localized scleroderma, so we established its clinical guideline ahead of all over the world. In particular, the clinical guideline was established by clinical questions based on evidence-based medicine according to the New Minds Clinical Practice Guideline Creation Manual (version 1.0). We aimed to make the guideline easy to use and reliable based on the newest evidence, and to present guidance as specific as possible for various clinical problems in treatment of localized scleroderma.

Tryptophan photo-product FICZ upregulates AHR/MEK/ERK-mediated MMP1 expression: Implications in anti-fibrotic phototherapy.

BACKGROUND: Scleroderma is caused by aberrant transforming growth factor-ß signaling. The degradation of extracellular matrix proteins is regulated by matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs). Ultraviolet (UV) radiation has been a therapy for scleroderma. 6-Formylindolo[3,2-b]carbazole (FICZ), an endogenous aryl hydrocarbon receptor (AHR) ligand, is a tryptophan metabolite generated by UV exposure. Nonetheless, whether FICZ regulates MMPs and TIMPs has not been investigated. OBJECTIVE: To elucidate the regulatory roles of FICZ in the expression of MMPs and TIMPs in normal human dermal fibroblasts (NHDFs). METHODS: Quantitative real-time polymerase chain reaction was performed to determine the expression of MMPs or TIMPs in the NHDFs treated with FICZ or UVB. The MMPs levels were measured by enzyme-linked immunosorbent assay. The actions of FICZ on MMPs were analyzed using AHR-knockdown NHDFs or selective inhibitors of mitogen-activated protein kinases (MAPKs). Microtubule-associated protein kinase (MEK) and extracellular signal-regulated kinase (ERK) phosphorylation was examined by western blotting. RESULTS: UVB increased the mRNA and protein levels of MMP1 and MMP3 in NHDFs, while FICZ upregulated those of MMP1, but not MMP3. The effects of FICZ on TIMPs were negligible. FICZ increased MMP1 expression in an AHR-dependent manner. The FICZ-induced MMP1 upregulation was ameliorated with MEK/ERK inhibitors, whereas the effects of UVB were canceled with c-Jun N-terminal kinase (JNK) and p38-MAPK as well as MEK/ERK inhibitors. FICZ-induced ERK phosphorylation is dependent on AHR. CONCLUSION: FICZ contributes to the UV-mediated anti-fibrotic effects via the AHR/MEK/ERK signal pathway in NHDFs. FICZ is a potential therapeutic agent for scleroderma.

Phototherapy in systemic sclerosis: Review.

Systemic scleroderma-also known as systemic sclerosis (SSc)-is a chronic systemic connective tissue disease characterized by collagen deposition in cutaneous and internal organs, leading to skin sclerosis and multiple organ fibrosis. The pathogenesis is complex and remains poorly understood. Treatment is based on organ involvement and requires a multidisciplinary approach. Skin sclerosis can cause disability, leading to decreasing quality of life. Various systemic antifibrotic therapies have been used; however, most have unsatisfactory results. Recently, phototherapy and in particular ultraviolet A (UVA) has been used to treat skin sclerosis in SSc patients with satisfactory results. The main mechanisms include lymphocyte apoptosis, cytokine alteration, inhibition of collagen synthesis and increased collagenase production, and neovascularization, leading to the breakdown of collagen fibrils resulting in skin softening or even healing digital ulcers. Most studies reported that psoralen plus UVA (PUVA) and UVA1 phototherapy improved clinical outcomes vis-à-vis skin sclerosis, joint mobility, ulcers, and histopathology. PUVA and UVA1 phototherapy therefore have potential as an alternative or adjunctive therapy for patients with SSc.

Nintedanib inhibits fibroblast activation and ameliorates fibrosis in preclinical models of systemic sclerosis.

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.

Dissection of the mechanism of traditional Chinese medical prescription-Yiqihuoxue formula as an effective anti-fibrotic treatment for systemic sclerosis.

BACKGROUND: Systemic sclerosis (SSc) is a connective tissue fibrotic disease for which there is no effective treatment. Traditional Chinese Medicine (TCM), such as the Yiqihuoxue formula used in Shanghai TCM-integrated Hospital, has shown the efficacy of anti-fibrosis in clinical applications. This study was aiming to dissect the anti-fibrotic mechanism of Yiqihuoxue treatment for SSc. METHODS: Bleomycin-induced mice and SSc dermal fibroblasts were treated with Yiqihuoxue decoction; NIH-3T3 fibroblasts were exposed to exogenous TGF-ß1, and then cultured with or without Yiqihuoxue decoction. Luciferase reporter gene assay was used to determine the activity of Smad binding element (SBE). Quantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to examine the mRNA levels of extracellular matrix (ECM) genes. The protein levels of type I collagen, Smad3 and phosphorylated-Smad3 (p-Smad3) were detected by western blotting. Student's t-tests were used to determine the significance of the results. RESULTS: Bleomycin-induced mice, SSc dermal fibroblasts and TGF-ß1-induced NIH/3T3 fibroblasts showed higher levels of ECM gene transcriptions and collagen production. In addition, the phosphorylation level of Smad3 and activity of SBE were significantly increased after exogenous TGF-ß1 induction. Whereas, Yiqihuoxue treatment could obviously attenuate fibrosis in bleomycin-induced mice, down regulate ECM gene expressions and collagen production in SSc dermal fibroblasts and TGF-ß1-induced NIH/3T3 fibroblasts. Furthermore, the aberrantly high phosphorylation level of Smad3 and activity of SBE in the TGF-ß1-induced NIH/3T3 fibroblasts were also dramatically decreased by Yiqihuoxue treatment. CONCLUSIONS: Yiqihuoxue treatment could effectively reduce collagen production via down-regulating the phosphorylation of Smad3 and then the activity of SBE, which are involved in the TGF-ß pathway and constitutively activated in the progression of SSc.

A synthetic PPAR-γ agonist triterpenoid ameliorates experimental fibrosis: PPAR-γ-independent suppression of fibrotic responses.

BACKGROUND: Persistent fibroblast activation initiated by transforming growth factor ß (TGF-ß) is a fundamental event in the pathogenesis of systemic sclerosis, and its pharmacological inhibition represents a potential therapeutic strategy. The nuclear receptor, peroxisome proliferator-activated receptor γ (PPAR-γ), exerts potent fibrotic activity. The synthetic oleanane triterpenoid, 2-cyano-3,12-dioxo-olean-1,9-dien-28-oic acid (CDDO), is a PPAR-γ agonist with potential effects on TGF-ß signalling and dermal fibrosis. OBJECTIVE: To examine the modulation of fibrogenesis by CDDO in explanted fibroblasts, skin organ cultures and murine models of scleroderma. MATERIAL AND METHODS: The effects of CDDO on experimental fibrosis induced by bleomycin injection or by overexpression of constitutively active type I TGF-ß receptor (TgfbR1ca) were evaluated. Modulation of fibrotic gene expression was examined in human skin organ cultures. To delineate the mechanisms underlying the antifibrotic effects of CDDO, explanted skin fibroblasts cultured in two-dimensional monolayers or in three-dimensional full-thickness human skin equivalents were studied. RESULTS: CDDO significantly ameliorated dermal fibrosis in two complementary mouse models of scleroderma, as well as in human skin organ cultures and in three-dimensional human skin equivalents. In two-dimensional monolayer cultures of explanted normal fibroblasts, CDDO abrogated fibrogenic responses induced by TGF-ß. These CDDO effects occurred via disruption of Smad-dependent transcription and were associated with inhibition of Akt activation. In scleroderma fibroblasts, CDDO attenuated the elevated synthesis of collagen. Remarkably, the in vitro antifibrotic effects of CDDO were independent of PPAR-γ. CONCLUSIONS: The PPAR-γ agonist triterpenoid CDDO attenuates fibrogenesis by antagonistically targeting canonical TGF-ß/Smad and Akt signalling in a PPAR-γ-independent manner. These findings identify this synthetic triterpenoid as a potential new therapy for the control of fibrosis.

Effects of oligoelements Se, Zn, and Mn plus Lachesis muta venom in experimental scleroderma.

Scleroderma, sclerosis of the skin, is a severe autoimmune disease refractant to all kind of treatments. To study the in vivo effects of a combination of three oligoelements selenium (Se), zinc (Zn), and manganese (Mn) plus Lachesis muta venom (O-LM) on the bleomycin (BLM)-induced scleroderma mouse experimental model. C3H mice were randomly divided into four groups: control (phosphate-buffered saline (PBS)), O-LM, BLM, and BLM + O-LM. All administrations were performed subcutaneously into the back of mice. BLM was injected 5 days per week for three consecutive weeks and O-LM was administered simultaneously with BLM from the beginning of the experiments and lasted for 3 weeks after the final BLM or PBS injection (for O-LM and BLM + O-LM groups), when animals were sacrificed and histopathological, immunohistochemical, thiobarbituric acid reactive species (TBARS) evaluation, and autoantibodies detection were determined. O-LM significantly reduced BLM-induced enhanced dermal thickness (605 ± 47 vs. 956 ± 59 µm, P < 0.01), collagen deposition, and mast cells infiltration (43.1 ± 1.0 vs. 102 ± 14.1 mast cells, P < 0.05). O-LM administration significantly blocked BLM-induced oxidative damage and the enhanced immunoreactive fibroblasts for α-smooth muscle actin while reduced BLM-induced autoantibodies that strongly react mainly with skin and spleen. O-LM significantly reduced BLM-induced scleroderma through the modulation of antioxidant and immunological pathways.

Levels of target activation predict antifibrotic responses to tyrosine kinase inhibitors.

OBJECTIVES: To assess whether the discrepancy between the strong antifibrotic effects of tyrosine kinase inhibitors (TKIs) in animal models and the inconsistent results in clinical studies might be related to the activation levels of drug targets. METHODS: Skin sections of bleomycin, TSK1, Fra-2 transgenic mice, SSc patients and controls were analysed by histology and immunohistochemistry. Subgroups of mice were treated with the TKIs nilotinib or imatinib. Differences in the activation levels of the TKI targets p-PDGFRß (platelet derived growth factor ß) and p-c-abl were assessed. RESULTS: In bleomycin and TSK1 mice, expression of activated p-PDGFRß (platelet derived growth factor receptor ß) and p-c-abl was ubiquitous with strong upregulation compared with controls. Treatment with TKIs resulted in successful target inhibition and consequently reduced dermal fibrosis. In the Fra-2 model, the activation levels of p-PDGFRß and p-c-abl were much lower than in the bleomycin and the TSK1 models. Accordingly, nilotinib did not prevent dermal fibrosis and target inhibition was unsuccessful. Notably, in skin biopsies of SSc patients, the mean activation levels of TKI targets were only moderate and in the majority of patients resembled those of the non-responsive Fra-2 model. CONCLUSIONS: Animal models for proof-of-concept studies should be selected based on a similar activation level and expression pattern of drug targets as in human SSc.