IntroductionAdenosine, acting through the A2A receptor, promotes tissue matrix production in the skin and the liver and induces the development of dermal fibrosis and cirrhosis in murine models. Since expression of A2A receptors is increased in scleroderma fibroblasts, we examined the mechanisms by which the A2A receptor produces its fibrogenic effects.MethodsThe effects of A2A receptor ligation on the expression of the transcription factor, Fli1, a constitutive repressor for the synthesis of matrix proteins, such as collagen, is studied in dermal fibroblasts. Fli1 is also known to repress the transcription of CTGF/CCN2, and the effects of A2A receptor stimulation on CTGF and TGF-β1 expression are also examined.ResultsA2A receptor occupancy suppresses the expression of Fli1 by dermal fibroblasts. A2A receptor activation induces the secretion of CTGF by dermal fibroblasts, and neutralization of CTGF abrogates the A2A receptor-mediated enhancement of collagen type I production. A2AR activation, however, resulted in a decrease in TGF-β1 protein release.ConclusionsOur results suggest that Fli1 and CTGF are important mediators of the fibrogenic actions of adenosine and the use of small molecules such as adenosine A2A receptor antagonists may be useful in the therapy of dermal fibrosis in diseases such as scleroderma.
BackgroundFibrosing diseases are a leading cause of morbidity and mortality worldwide and, therefore, there is a need for safe and effective antifibrotic therapies. Adenosine, generated extracellularly by the dephosphorylation of adenine nucleotides, ligates specific receptors which play a critical role in development of hepatic and dermal fibrosis. Results of recent clinical trials indicate that tenofovir, a widely used antiviral agent, reverses hepatic fibrosis/cirrhosis in patients with chronic hepatitis B infection. Belonging to the class of acyclic nucleoside phosphonates, tenofovir is an analogue of AMP. We tested the hypothesis that tenofovir has direct antifibrotic effects in vivo by interfering with adenosine pathways of fibrosis using two distinct models of adenosine and A2AR-mediated fibrosis.MethodsThioacetamide (100mg/kg IP)-treated mice were treated with vehicle, or tenofovir (75mg/kg, SubQ) (n = 5–10). Bleomycin (0.25U, SubQ)-treated mice were treated with vehicle or tenofovir (75mg/kg, IP) (n = 5–10). Adenosine levels were determined by HPLC, and ATP release was quantitated as luciferase-dependent bioluminescence. Skin breaking strength was analysed and H&E and picrosirus red-stained slides were imaged. Pannexin-1expression was knocked down following retroviral-mediated expression of of Pannexin-1-specific or scrambled siRNA.ResultsTreatment of mice with tenofovir diminished adenosine release from the skin of bleomycin-treated mice and the liver of thioacetamide-treated mice, models of diffuse skin fibrosis and hepatic cirrhosis, respectively. More importantly, tenofovir treatment diminished skin and liver fibrosis in these models. Tenofovir diminished extracellular adenosine concentrations by inhibiting, in a dose-dependent fashion, cellular ATP release but not in cells lacking Pannexin-1.ConclusionsThese studies suggest that tenofovir, a widely used antiviral agent, could be useful in the treatment of fibrosing diseases.
Adenosine A receptor (AR) stimulation promotes the synthesis of collagens I and III, and we have recently demonstrated that there is crosstalk between the AR and WNT/β-catenin signaling pathway. In in vitro studies, AR signaling for collagen III expression was mediated by WNT/β-catenin signaling in human dermal fibroblasts; we further verified whether the crosstalk between AR and Wnt/β-catenin signaling was involved in diffuse dermal fibrosis in vivo. Wnt-signaling reporter mice (Tcf/Lef:H2B-GFP) were challenged with bleomycin and treated with the selective AR antagonist istradefylline (KW6002) or vehicle. Dermal fibrosis was quantitated and nuclear translocation of β-catenin in fibroblasts was assessed by double-staining for Green fluorescent protein or dephosphorylated β-catenin or β-catenin phosphorylated at Ser552, and vimentin. KW6002 significantly reduced skin thickness, skinfold thickness, breaking tension, dermal hydroxyproline content, myofibroblast accumulation, and collagen alignment in bleomycin-induced dermal fibrosis. Also, there was increased expression of Tcf/Lef:H2B-GFP reporter in bleomycin-induced dermal fibrosis, an effect that was diminished by treatment with KW6002. Moreover, KW6002 significantly inhibited nuclear translocation of Tcf/Lef:H2B-GFP reporter, as well as dephosphorylated β-catenin and β-catenin phosphorylated at Ser552. Our work supports the hypothesis that pharmacologic blockade of AR inhibits the WNT/β-catenin signaling pathway, contributing to its capacity to inhibit dermal fibrosis in diseases such as scleroderma.
ObjectiveMultiple myeloma (MM) patients with bone destruction are difficult to restore, so it is of great clinical significance to further explore the factors affecting MM bone destruction.Methods and resultsThis study retrospectively analyzed 419 cases with MM. Multiple linear regression analysis showed that those MM patients with a higher concentration of Ca2+ in serum, higher positive rate of CD138 immuno-phenotype and advanced in stage with 13q34 deletion in cytogenetics would be more prone to bone destruction, while total bile acid (TBA) and kappa chain isotope negatively correlated with bone destruction in MM patients. The Kaplan–Meier analysis indicated that Ca2+, serum β2-microglobulin (β2-MG), hemoglobin (HGB), creatinine (CREA), uric acid (UA) and age correlated with the survival of bone destruction in MM patients. Cox regression analysis further showed that the independent prognostic factors of β2-MG and CREA had a higher risk for early mortality in bone destruction patients. Moreover, an index was calculated based on β2-MG and globulin (GLB) to white blood cell (WBC) ratio to predict the poor survival of bone destruction patients.ConclusionWe provide a novel marker to predict the prognosis of myeloma patients using routine examination method instead of bone marrow aspiration, and provide a reference for clinical evaluation.
Purpose This study was to evaluate existing staging system of multiple myeloma (MM) in the real world. Methods We retrospectively analyzed 886 newly diagnosed MM from two institutions. Results The overall survival (OS) of eligible patients was 61.0 months. R-ISS held a larger receiver operating characteristic curve (ROC) area (0.603) than that of ISS (0.573) and DS staging system (0.567). In the group of immunomodulatory agents-based regimens, the median OS was 92.0 months in R-ISS I, 63.0 months in R-ISS II and 18.0 months in R-ISS III (p<0.0001). In the group of proteasome inhibitors-based regimens, the median OS was 102.0 months in R-ISS I, 63.0 months in R-ISS II and 22.0 months in R-ISS III (p<0.0001). In different subgroups grouped according to Age, HGB, CREA and Ca, R-ISS also had a good stratification effect. Patients in R-ISS II were further analyzed, which accounted for 69.9% of all R-ISS patients. Using univariable and multivariable Cox analysis, Age>65 years (p=0.001), HGB<100g/L (p<0.001), elevated LDH (p=0.001) and Ca (p=0.010) were independent factors indicating worse prognosis for R-ISS II. Conclusion R-ISS remains a valuable staging system in the real world of new drug era. But patients classified in R-ISS II still have large heterogeneity.
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