41 research outputs found
15-Deoxy-Δ-12, 14-prostaglandin J2 acts cooperatively with prednisolone to reduce TGF-β-induced pro-fibrotic pathways in human osteoarthritis fibroblasts
[Abstract] Abstract
Background/aims: Synovial fibrosis is a pathological process that is observed in several musculoskeletal disorders and characterized by the excessive deposition of extracellular matrix, as well as cell migration and proliferation. Despite the fact that glucocorticoids are widely employed in the treatment of rheumatic pathologies such as osteoarthritis (OA) and rheumatoid arthritis, the mechanisms by which glucocorticoids act in the joint and their impacts on pro-fibrotic pathways are still unclear.
Materials: Human OA synovial fibroblasts were obtained from knee and hip joints. Cells were treated with prednisolone (1 mM) or transforming growth factor-beta 1 (TGF-β1) (10 ng/ml) for 1 and 7 days for quantification of RNA and protein expression (by real-time quantitative reverse transcription-PCR and western blot, respectively), 72 h for immunocytochemistry analysis, and 48 h for proliferation (by BrdU assay) and migration (by wound assay) studies. In addition, cells were preincubated with prednisolone and/or the peroxisome proliferator-activated receptor gamma (PPAR-γ) agonist 15-deoxy-Δ-12,14-prostaglandin J2 (15d-PGJ2) for 6 h before adding TGF-β1. pSmad1/5, pSmad2 and β-catenin levels were analyzed by Western blot. The activin receptor-like kinase-5 (ALK-5) inhibitor (SB-431542) was employed for the mechanistic assays.
Results: Prednisolone showed a predominant anti-fibrotic impact on fibroblast-like synoviocytes as it attenuated the spontaneous and TGF-β-induced gene expression of pro-fibrotic markers. Prednisolone also reduced α-sma protein and type III collagen levels, as well as cell proliferation and migration after TGF-β stimulation. However, prednisolone did not downregulate the gene expression of all the pro-fibrotic markers tested and did not restore the reduced PPAR-γ levels after TGF-β stimulation. Interestingly, anti-fibrotic actions of the glucocorticoid were reinforced in the presence of the PPAR-γ agonist 15d-PGJ2. Combined pretreatment modulated Smad2/3 levels and, similar to the ALK-5 inhibitor, blocked β-catenin accumulation elicited by TGF-β.
Conclusions: Prednisolone, along with 15d-PGJ2, modulates pro-fibrotic pathways activated by TGF-β in synovial fibroblasts at least partially through the inhibition of ALK5/Smad2 signaling and subsequent β-catenin accumulation. These findings shed light on the potential therapeutic effects of glucocorticoids treatment combined with a PPAR-γ agonist against synovial fibrosis, although future studies are warranted to further evaluate this concern
SARS-CoV-2 susceptibility and COVID-19 disease severity are associated with genetic variants affecting gene expression in a variety of tissues
Variability in SARS-CoV-2 susceptibility and COVID-19 disease severity between individuals is partly due to
genetic factors. Here, we identify 4 genomic loci with suggestive associations for SARS-CoV-2 susceptibility
and 19 for COVID-19 disease severity. Four of these 23 loci likely have an ethnicity-specific component.
Genome-wide association study (GWAS) signals in 11 loci colocalize with expression quantitative trait loci
(eQTLs) associated with the expression of 20 genes in 62 tissues/cell types (range: 1:43 tissues/gene),
including lung, brain, heart, muscle, and skin as well as the digestive system and immune system. We perform
genetic fine mapping to compute 99% credible SNP sets, which identify 10 GWAS loci that have eight or fewer
SNPs in the credible set, including three loci with one single likely causal SNP. Our study suggests that the
diverse symptoms and disease severity of COVID-19 observed between individuals is associated with variants across the genome, affecting gene expression levels in a wide variety of tissue types
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A positive response to infliximab in Crohn disease: Association with a higher systemic inflammation before treatment but not with-308 TNF gene polymorphism
Background: Two-thirds to three-fourths of patients with either refractory luminal or fistulizing Crohn disease respond to infliximab treatment. The ability or inability to respond seems to persist over time. Biological characteristics and/or genetic background can influence the response to treatment. The aim was to assess the value of C-reactive protein and TNF-alpha serum levels before treatment as well as the TNF -308 gene polymorphism in the prediction of response to infliximab treatment in Crohn disease. Methods: Two-hundred-and-twenty-six Crohn disease patients treated in the setting of an expanded access programme to infliximab in Belgium were studied. There were 136 refractory luminal diseases and 90 refractory fistulizing diseases. Luminal diseases were treated with one single infusion; fistulizing diseases with three infusions at weeks 0, 2 and 6. A clinical response to treatment was defined as either a Crohn disease activity index 5 mg/l) than in patients with a normal CRP value (< 5 mg/l) before treatment (76% versus 46%; P = 0.004; OR: 0.26 (0.11-0.63)). Allelic and genotype frequencies for -308 TNF gene polymorphis m were not significantly different between responders and non- responders - with the exception of a slightly higher TNF2 frequency in nonresponders in luminal disease (22.1% versus 11.6%; P = 0.04). However, this was not associated with a significant difference in genotype frequencies. Conclusion: A positive clinical response to infliximab was associated with a higher CRP level before treatment in our population of Crohn disease patients, but there was no relevant association with -308 TNF gene polymorphism. We therefore suggest that CRP level may help to identify better candidates for infliximab treatment
Thymopoietin and thymopentin enhance the levels of ACTH, beta-endorphin and beta-lipotropin from rat pituitary cells in vitro
Thymopoietin and thymopentin are well characterized polypeptides influencing
immunoregulation by several mechanisms. Proposed as a therapy in diseases with
major immune abnormalities such as rheumatoid arthritis, thymopentin improved
within 2 weeks some clinical parameters as pain and joint swelling. The
hypothesis that this spectacular effect could be mediated through interactions
with anti-inflammatory (ACTH) and pain relieving (beta-endorphin) hormones
producing cells was tested on the rat isolated pituitary cell model. Thymopentin
and thymopoietin can enhance in vitro the levels of ACTH, beta-endorphin and
beta-lipotropin in a time- and dose-dependent fashion for physiological
concentrations ranging from 10(-12) to 10(-8) mol/l. The action on pituitary
cells was restricted to those molecules as no changes occurred in LH, FSH, GH,
TSH and PRL levels, after otherwise identical experimental conditions
Validation of a new method by nano-liquid chromatography on chip tandem mass spectrometry for combined quantitation of C3f and the V65 vitronectin fragment as biomarkers of diagnosis and severity of osteoarthritis
peer reviewedMicrofluidic liquid chromatography coupled to a nanoelectrospray source ion trap mass spectrometry was used for the absolute and simultaneous quantitation of C3f and the V65 vitronectin fragment in serum. The method was first carefully optimized and then validated in serum biological matrix. Stable isotopes for the two biomarkers of interest were used as stable isotope labeled peptide standards. A weighted 1/x2 quadratic regression for C3f and a weighted 1/x quadratic regression for the V65 vitronectin peptide were selected for calibration curves. Trueness (with a relative bias <10%), precision (repeatability and intermediate precision <15%) and accuracy (risk <15%) of the method were successfully demonstrated. The linearity of results was validated in the concentration range of 2.5-200ng/mL for C3f and 2.5-100ng/mL for the V65 vitronectin fragment. Serum samples (n=147) classified in 7 groups [(healthy volunteers, OA with 5 grades of severity and rheumatoid arthritis (RA) patients] were analyzed with our new quantitative method. Our data confirm that C3f and the V65 vitronectin fragment are biomarkers of OA severity, but also that C3f fragment is further related to OA severity whereas the V65 vitronectin fragment is more related to early OA detection
Clinical and ultrasonographic predictors of joint replacement for knee osteoarthritis: results from a large, 3-year, prospective EULAR study
OBJECTIVES: To determine clinical and ultrasonographic predictors of joint
replacement surgery across Europe in primary osteoarthritis (OA) of the knee.
METHODS: This was a 3-year prospective study of a painful OA knee cohort (from a
EULAR-sponsored, multicentre study). All subjects had clinical evaluation,
radiographs and ultrasonography (US) at study entry. The rate of knee replacement
surgery over the 3-year follow-up period was determined using Kaplan-Meier
survival data analyses. Predictive factors for joint replacement were identified
by univariate log-rank test then multivariate analysis using a Cox
proportional-hazards regression model. Potential baseline predictors included
demographic, clinical, radiographic and US features. RESULTS: Of the 600 original
patients, 531 (88.5%), mean age 67+/-10 years, mean disease duration 6.1+/-6.9
years, had follow-up data and were analysed. During follow-up (median 3 years;
range 0-4 years), knee replacement was done or required for 94 patients
(estimated event rate of 17.7%). In the multivariate analysis, predictors of
joint replacement were as follows: Kellgren and Lawrence radiographic grade
(grade > or =III vs <III, hazards ratio (HR) = 4.08 (95% CI 2.34 to 7.12),
p or =4 mm vs <4 mm) (HR = 2.63 (95%
CI 1.70 to 4.06), p<0.0001); knee pain intensity on a 0-100 mm visual analogue
scale (> or =60 vs <60) (HR = 1.81 (95% CI 1.15 to 2.83), p=0.01) and disease
duration (> or =5 years vs <5 years) (HR=1.63 (95% CI 1.08 to 2.47), p=0.02).
Clinically detected effusion and US synovitis were not associated with joint
replacement in the univariate analysis. CONCLUSION: Longitudinal evaluation of
this OA cohort demonstrated significant progression to joint replacement. In
addition to severity of radiographic damage and pain, US-detected effusion was a
predictor of subsequent joint replacement