Inflammatory Mesenchymal Stem Cells Express Abundant Membrane-Bound and Soluble Forms of C-Type Lectin-like CD248.

CD248 (endosialin) belongs to a glycoprotein family that also includes thrombomodulin (CD141), CLEC14A, and CD93 (AA4) stem cell markers. We analyzed the regulated expression of CD248 in vitro using skin (HFFF) and synovial (FLS) mesenchymal stem cell lines, and in fluid and tissue samples of rheumatoid arthritis (RA) and osteoarthritis (OA) patients. Cells were incubated with either rhVEGF165, bFGF, TGF-ß1, IL1-ß, TNF-α, TGFß1, IFN-γ, or PMA (Phorbol ester). There was no statistically significant change in membrane expression. A soluble (s) form of cleaved CD248 (sCD248) was detected after cell treatment with IL1-ß and PMA. Matrix metalloprotease (MMP) MMP-1 and MMP-3 mRNAs were significantly up-regulated by IL1-ß and PMA. A broad MMP inhibitor blocked the release of soluble CD248. In RA synovial tissue, we identified CD90+ perivascular MSCs double-stained for CD248 and VEGF. High sCD248 levels were detected in synovial fluid from RA. In culture, subpopulations of CD90+ CD14- RA MSCs were either identified as CD248+ or CD141+ cells but CD93-. CD248 is abundantly expressed by inflammatory MSCs and shed in an MMP-dependent manner in response to cytokines and pro-angiogenic growth factors. Both membrane-bound and soluble CD248 (acting as a decoy receptor) may contribute to RA pathogenesis.

Human Synovial Mesenchymal Stem Cells Expressed Immunoregulatory Factors IDO and TSG6 in a Context of Arthritis Mediated by Alphaviruses.

Infection by arthritogenic alphaviruses (aavs) can lead to reactive arthritis, which is characterized by inflammation and persistence of the virus; however, its mechanisms remain ill-characterized. Intriguingly, it has been shown that viral persistence still takes place in spite of robust innate and adaptive immune responses, characterized notably by the infiltration of macrophages (sources of TNF-alpha) as well as T/NK cells (sources of IFN-gamma) in the infected joint. Aavs are known to target mesenchymal stem cells (MSCs) in the synovium, and we herein tested the hypothesis that the infection of MSCs may promote the expression of immunoregulators to skew the anti-viral cellular immune responses. We compared the regulated expression via human synovial MSCs of pro-inflammatory mediators (e.g., IL-1ß, IL6, CCL2, miR-221-3p) to that of immunoregulators (e.g., IDO, TSG6, GAS6, miR146a-5p). We used human synovial tissue-derived MSCs which were infected with O'Nyong-Nyong alphavirus (ONNV, class II aav) alone, or combined with recombinant human TNF-α or IFN-γ, to mimic the clinical settings. We confirmed via qPCR and immunofluorescence that ONNV infected human synovial tissue-derived MSCs. Interestingly, ONNV alone did not regulate the expression of pro-inflammatory mediators. In contrast, IDO, TSG6, and GAS6 mRNA expression were increased in response to ONNV infection alone, but particularly when combined with both recombinant cytokines. ONNV infection equally decreased miR-146a-5p and miR-221-3p in the untreated cells and abrogated the stimulatory activity of the recombinant TNF-α but not the IFN-gamma. Our study argues for a major immunoregulatory phenotype of MSCs infected with ONNV which may favor virus persistence in the inflamed joint.

Visceral adiposity in patients with psoriatic arthritis and psoriasis alone and its relationship with metabolic and cardiovascular risk.

BACKGROUND: Fat mass distribution, especially in the abdominal visceral region, has been rarely evaluated in patients with PsA or psoriasis (PsO). METHODS: Patients with PsA and patients with PsO alone were evaluated and compared with control subjects (1:1 ratio in each patient group) matched for age, sex and BMI category. Body composition and fat distribution (android and visceral fat) were evaluated by DXA. Anthropometric measurements, disease activity and the systematic coronary risk evaluation (SCORE) cardiovascular risk were assessed. Metabolic parameters (insulin, homeostasis model assessment for insulin resistance), serum adipokines [total and high-molecular-weight adiponectin, leptin, resistin and retinol-binding protein-4 (RBP4)] were measured. RESULTS: Data for 52 patients with PsA and 52 patients with PsO and their respective paired controls were analysed. Android fat and visceral fat were found to be significantly higher in patients with PsO compared with their controls, while these measurements did not differ between patients with PsA and their controls. By multivariate analysis, after adjusting for age, sex and BMI, visceral fat was higher in PsO patients compared with PsA patients (P = 0.0004) and the whole group of controls (P = 0.0013). Insulin levels and HOMA-IR were increased in both PsA and PsO groups. High-molecular-weight/total adiponectin ratio was decreased in patients with PsO. RBP4 was significantly higher in both PsA and PsO patients. In patients with PsO, visceral fat strongly correlated with SCORE (r = 0.61). CONCLUSION: Visceral fat accumulates more in PsO alone than in PsA. Visceral adiposity may be a more pressing concern in PsO relative to PsA. TRIAL REGISTRATION: The ADIPSO study (Évaluation du tissu ADIpeux et des adipokines dans le PSOriasis et le rhumatisme psoriasique et analyse de ses relations avec le risque cardiovasculaire) is a case-control study conducted in Besançon, France, and is registered on ClinicalTrials.gov under the number NCT02849795.

Epigenetic Regulation (Including Micro-RNAs, DNA Methylation and Histone Modifications) of Rheumatoid Arthritis: A Systematic Review.

The inflammatory reaction in rheumatoid arthritis (RA) is controlled by major epigenetic modifications that modulate the phenotype of synovial and immune cells. The aim of this work was to perform a systematic review focusing on miR expression, DNA methylation and histone modifications in RA. We demonstrated that, in human samples, the expressions of miR-155, miR-146a and miR-150 were significantly decreased while the expression of miR-410-3p was significantly increased in the RA group. Moreover, miR-146a significantly decreased pro-autoimmune IL-17 cytokine expression in RA. In a murine model, miR-34a inhibition can ameliorate the arthritis score. However, this evidence remain critically insufficient to support current therapeutic applications in RA patients.

Chikungunya-Induced Arthritis in Reunion Island: A Long-Term Observational Follow-Up Study Showing Frequently Persistent Joint Symptoms, Some Cases of Persistent Chikungunya Immunoglobulin M Positivity, and No Anticyclic Citrullinated Peptide Seroconversion After 13 Years.

BACKGROUND: Reunion Island was struck by a massive Chikungunya outbreak in 2005-2006. Chikungunya infection is characterized by inflammatory joint symptoms, which may evolve into chronic arthritis. METHODS: In this long-term longitudinal observational monocentric study, after the 2005-2006 outbreak in Reunion Island, 159 patients were first referred to a rheumatologist for post-Chikungunya chronic musculoskeletal pain, 73 of them were diagnosed with classifiable Chikungunya-related chronic inflammatory rheumatic diseases (>3 month symptom duration from the initial viral infection). Thirty of these 73 patients were clinically evaluated by a second rheumatologist in 2018-2019. The main objective of this second examination was to estimate the proportion of patients with persistent Chikungunya-related inflammatory joint symptoms after 13 years. RESULTS: Inflammatory joint symptoms persisted in 17/30 patients after 13 years (therefore in at least 23.3% of the 73 patients initially diagnosed with Chikungunya-related inflammatory joint symptoms and 10.7% of the 159 patients referred for post-Chikungunya chronic musculoskeletal pain). In the symptom persistence subgroup, the prevalence of positive autoantibodies (antinuclear or ACPA) was significantly higher - without any seroconversion, Chikungunya IgG and IgM levels were higher, long-term IgM positivity and radiographic damage were more frequent. Overall, after 13 years, pain and fatigue levels remained significant, 5 patients were still treated by methotrexate, 3 by TNF-blockers, highlighting long-term Chikungunya-related patient burden. CONCLUSIONS: Such a long-term persistence of Chikungunya-related chronic inflammatory rheumatic diseases had not been reported so far. Furthermore, the long-term Chikungunya IgM positivity we observed in some cases might corroborate the hypothesis of residual viral antigen-driven chronic arthritis.

Deciphering SARS-CoV-2 Virologic and Immunologic Features.

Severe acute respiratory syndrome coronavirus (SARS-CoV)-2 and its associated pathology, COVID-19, have been of particular concerns these last months due to the worldwide burden they represent. The number of cases requiring intensive care being the critical point in this epidemic, a better understanding of the pathophysiology leading to these severe cases is urgently needed. Tissue lesions can be caused by the pathogen or can be driven by an overwhelmed immune response. Focusing on SARS-CoV-2, we and others have observed that this virus can trigger indeed an immune response that can be dysregulated in severe patients and leading to further injury to multiple organs. The purpose of the review is to bring to light the current knowledge about SARS-CoV-2 virologic and immunologic features. Thus, we address virus biology, life cycle, tropism for many organs and how ultimately it will affect several host biological and physiological functions, notably the immune response. Given that therapeutic avenues are now highly warranted, we also discuss the immunotherapies available to manage the infection and the clinical outcomes.

Methotrexate an Old Drug with New Tricks.

Methotrexate (MTX) is the first line drug for the treatment of a number of rheumatic and non-rheumatic disorders. It is currently used as an anchor disease, modifying anti-rheumatic drug in the treatment of rheumatoid arthritis (RA). Despite the development of numerous new targeted therapies, MTX remains the backbone of RA therapy due to its potent efficacy and tolerability. There has been also a growing interest in the use of MTX in the treatment of chronic viral mediated arthritis. Many viruses-including old world alphaviruses, Parvovirus B19, hepatitis B/C virus, and human immunodeficiency virus-have been associated with arthritogenic diseases and reminiscent of RA. MTX may provide benefits although with the potential risk of attenuating patients' immune surveillance capacities. In this review, we describe the emerging mechanisms of action of MTX as an anti-inflammatory drug and complementing its well-established immunomodulatory activity. The mechanisms involve adenosine signaling modulation, alteration of cytokine networks, generation of reactive oxygen species and HMGB1 alarmin suppression. We also provide a comprehensive understanding of the mechanisms of MTX toxic effects. Lastly, we discussed the efficacy, as well as the safety, of MTX used in the management of viral-related rheumatic syndromes.

Use of qNMR for speciation of flaxseeds (Linum usitatissimum) and quantification of cyanogenic glycosides.

This report describes a routine method taking less than 20 min to quantify cyanogenic glycosides such as linustatin and neolinustatin from flaxseeds (Linum usitatissimum L.) using 1H nuclear magnetic resonance. After manual dehulling, a higher linustatin content was shown in the almond fraction, while neolinustatin and total cyanogenic glycoside contents were significantly higher in hulls. Linustatin and neolinustatin were quantified in seven cultivars grown in two locations in three different years. Linustatin, neolinustatin, and total cyanogenic glycosides ranged between 91 and 267 mg/100 g, 78-272 mg/100 g, and 198-513 mg/100 g dry weight flaxseeds, respectively. NMR revealed differences of up to 70% between samples with standard deviation variations lower than 6%. This study shows that NMR is a very suitable tool to perform flaxseed varietal selection for the cyanogenic glycoside content. Graphical abstract qNMR can be used to perform flaxseed varietal selection for the cyanogenic glycoside content.

Utility of 18F-fluoro-dexoxyglucose positron emission tomography for the diagnosis of polymyalgia rheumatica: a controlled study.

OBJECTIVES: To compare (18)F-fluoro-dexoxyglucose PET/CT (FDG-PET/CT) findings in patients with polymyalgia rheumatica (PMR) and controls without rheumatologic disease. METHODS: We retrospectively included 50 patients with a diagnosis of PMR as well as 53 patients with a neoplasm as a control group. All patients underwent FDG-PET/CT. Seventeen hotspots were analysed. We performed a semi-quantitative analysis of FDG uptake (4-point score from 0 to 3). The cut-offs for the number of sites with high activity and for FDG uptake score were assessed using receiver operating characteristics curves and odds ratios (ORs). RESULTS: The two groups were comparable for the median patient age (69.3 years for PMR vs 68.1 for controls). Significant differences between the two groups were found for FDG uptake score (1.12 vs 0.34, P < 0.00001) and for the number of sites with significant uptake (score ⩾ 2): 6.36 sites vs 1.49 sites (P < 0.00001). The presence of three or more sites with significant uptake was correlated with the diagnosis of PMR with 74% sensitivity and 79% specificity (OR = 10.8). For the FDG uptake score, the cut-off was 0.53 (sensitivity 80%, specificity 77%, OR = 13.6). We found significant differences in all sites for FDG uptake score and the number of sites with significant uptake, particularly marked for shoulders, ischial tuberosities and interspinous bursitis (P < 0.00001 for FDG uptake score). CONCLUSION: Our results suggest that the number of sites with significant FDG uptake and the uptake score could be relevant criteria for the diagnosis of PMR.

PT-Flax (phenotyping and TILLinG of flax): development of a flax (Linum usitatissimum L.) mutant population and TILLinG platform for forward and reverse genetics.

BACKGROUND: Flax (Linum usitatissimum L.) is an economically important fiber and oil crop that has been grown for thousands of years. The genome has been recently sequenced and transcriptomics are providing information on candidate genes potentially related to agronomically-important traits. In order to accelerate functional characterization of these genes we have generated a flax EMS mutant population that can be used as a TILLinG (Targeting Induced Local Lesions in Genomes) platform for forward and reverse genetics. RESULTS: A population of 4,894 M2 mutant seed families was generated using 3 different EMS concentrations (0.3%, 0.6% and 0.75%) and used to produce M2 plants for subsequent phenotyping and DNA extraction. 10,839 viable M2 plants (4,033 families) were obtained and 1,552 families (38.5%) showed a visual developmental phenotype (stem size and diameter, plant architecture, flower-related). The majority of these families showed more than one phenotype. Mutant phenotype data are organised in a database and can be accessed and searched at UTILLdb (http://urgv.evry.inra.fr/UTILLdb). Preliminary screens were also performed for atypical fiber and seed phenotypes. Genomic DNA was extracted from 3,515 M2 families and eight-fold pooled for subsequent mutant detection by ENDO1 nuclease mis-match cleavage. In order to validate the collection for reverse genetics, DNA pools were screened for two genes coding enzymes of the lignin biosynthesis pathway: Coumarate-3-Hydroxylase (C3H) and Cinnamyl Alcohol Dehydrogenase (CAD). We identified 79 and 76 mutations in the C3H and CAD genes, respectively. The average mutation rate was calculated as 1/41 Kb giving rise to approximately 9,000 mutations per genome. Thirty-five out of the 52 flax cad mutant families containing missense or codon stop mutations showed the typical orange-brown xylem phenotype observed in CAD down-regulated/mutant plants in other species. CONCLUSIONS: We have developed a flax mutant population that can be used as an efficient forward and reverse genetics tool. The collection has an extremely high mutation rate that enables the detection of large numbers of independant mutant families by screening a comparatively low number of M2 families. The population will prove to be a valuable resource for both fundamental research and the identification of agronomically-important genes for crop improvement in flax.

Trehalose determination in linseed subjected to osmotic stress. HPAEC-PAD analysis: an inappropriate method.

Trehalose is a non-reducing disaccharide involved in stress tolerance in plants. To understand better the role of trehalose in the osmotic stress response in linseed (Linum usitatissimum), trehalose content in leaves was studied. First, the method commonly used for sugar determination, high performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD), gave unsatisfactory results and the separation efficiency could not be improved by varying the elution conditions. The same problem was also found in the model plant: Arabidopsis thaliana. After clearly highlighting a co-elution of trehalose in these two species by a trehalase assay and liquid chromatography-high resolution mass spectrometry analysis, gas chromatography-mass spectrometry (GC-MS) was used as the analytical method instead. These results confirmed that trehalose content is currently overestimated by HPAEC-PAD analysis, approximately 7 and 13 times for A. thaliana and linseed respectively. Thus GC-MS gave more satisfactory results for trehalose quantification in plants. With this method, trehalose accumulation was observed in linseed during an osmotic stress (-0.30 MPa), the quantity (31.49 nmol g(-1) dry weight after 48 h) appears too low to assign an osmoprotector or osmoregulator role to trehalose in stressed linseed.

Flexor digitorum profundus tendon injuries in Zone 2 repaired with a modified Mantero technique.

From January 2010 to January 2017, 81 complete flexor digitorum profundus tendon disruptions in Zones 2B and 2C were treated using the modified Mantero technique. The patients were re-examined at a mean of 62 months (range 30-96) after operation. We analysed outcomes against ages, gender, pulley integrity, associated injuries and follow-up times. The median total range of motion of both interphalangeal joints, distal interphalangeal joint alone and Quick DASH scores were significantly better for the group with pulley vented versus no pulley vented. According to the Strickland and Glogovac criteria, 76 (91%) had excellent or good, five fair and none had poor results. There were no complications except for one deep and one superficial infection at the site of the injury. There were no tendon ruptures and only three patients (3.7%) required secondary tenolysis. The modified Mantero repair is recommended as an alternative in the repair of tendon disruptions in Zone 2B and 2C. The good results and absence of ruptures suggest that the tendon healing and strength of repair are adequate for immediate postoperative motion.Level of evidence: IV.

Gonococcal arthritis: case series of 58 hospital cases.

OBJECTIVES: Extra-genital manifestations of gonococcal infection are rare (0.5-3%). Among them, gonococcal arthritis (GA) is the most frequent, accounting for 30-90% of disseminated infections. Our study aimed to describe all hospital cases of GA in Reunion Island, a French overseas territory. METHODS: We conducted a retrospective, multicentric, observational study of all cases of certain, probable or possible GA from 2008 to 2020. RESULTS: We identified 58 cases of GA, mostly certain cases (n = 48). Sex ratio was balanced, but men were older than women (51 vs 27 years, p < 0.001). A total of 41% had travelled abroad during the previous 3 months, mostly in Madagascar or South-East Asia. The most frequently infected joint was the knee, followed by ankle, wrist and fingers or carpal joints. Only 16% of cases had genital symptoms, but 50% had another extra-genital manifestation, mainly skin lesions (40%). Positivity rate of joint puncture was 91%, with a purulent liquid. Only 58% had a positive culture, and 33% had only a positive PCR. There was no 3GC-resistant strain. In comparison with gonococcal infection without arthritis, patients were older and had fewer genital but more extra-genital symptoms. On discharge 60% had persistent articular symptoms. GA represented 18% of all hospitalised septic arthritis cases with microbial identification in 2019. CONCLUSIONS: GA is rare but it is important to make an early diagnosis and treat promptly, as joint destruction may be important, leading to persistent symptoms after discharge. PCR use in joint puncture is useful in cases with negative culture.

What predicts initiation of osteoporosis treatment after fractures: education organisation or patients' characteristics?

OBJECTIVES: Fracture events due to osteoporosis (OP) are a major health burden in an ageing population. Their diagnosis and treatment provides the opportunity to prevent further fractures. However, the identification and treatment of underlying OP is often unsatisfactory. This longitudinal observational study, attempts to understand the barriers hindering OP treatment initiation in patients entering our hospital for fragility fracture. METHODS: 349 patients with fragility fracture underwent OP education (interview with a trained nurse) and were offered further OP care either with their general physician (or private rheumatologist) or at the hospital. In the latter case, the patients were given an appointment for OP-centred investigation and consultation. Six months after the fracture they were contacted to know whether they had been investigated and had started a treatment for OP (outcome). The factors predicting the outcome were analysed. RESULTS: The organisation of further OP care at the hospital yielded the highest probability of being treated (OR 118.09; 95%CI [13.93-1000.92]), while patient's education on OP had a slighter effect (OR 4.74; 95%CI [2.15-10.44]). A low social status was the strongest patient-related negative predictor of further treatment (OR 0.22 [95%CI 0.09-0.47]). CONCLUSIONS: The organisation of patients' OP care is the strongest determinant of OP investigation and treatment after fracture, and this aspect should be considered when attempting to increase OP care in everyday practice. Patients having a low social status are less likely to be investigated and treated, and additional efforts to properly organise their care are warranted.

Uveitis occurrence in early inflammatory back pain. Five years data from the prospective French nationwide DESIR cohort.

OBJECTIVE: Uveitis is a frequent extra rheumatological manifestation in axial Spondyloarthritis (SpA). The aim of study was to evaluate the prevalence and incidence of uveitis over the first five years of a prospective nationwide cohort of patients with high suspicion of early axial SpA, and to evaluate its associated factors. METHODS: DESIR is a prospective observational cohort of patients with recent onset inflammatory back pain (more than 3 months, less than 3 years), suggestive of axial SpA, All available factors in the database were compared between patients with and without uveitis at 5 years, by uni and then multivariate analysis. Baseline factors associated with new cases of uveitis occurrence over the 5 years were also analyzed. SIGNIFICANCE: P less than 0.05. RESULTS: After 5 years, 91 patients (out of 480 with complete follow-up) had at least one uveitis episode, giving an estimated prevalence of 18.9% [95% CI: 15.4-22.4]. In multivariate analysis, uveitis was significantly associated with dactylitis, and elevated ESR. New incident uveitis occurred in 31 cases over 5 years, giving an estimated incidence rate of 1.29 [0.84-1.74]/100 patient-years. Incidence of new uveitis was associated in multivariate analysis with baseline factors: diagnosis of SpA, sacro iliac MRI inflammatory SPARCC score, dactylitis, syndesmophyte score. No significant association was found with HLA-B27, DMARDs, BASDAI, ASDAS, BASFI. CONCLUSION: Five-years data of the DESIR cohort allowed an estimation of incidence rate of uveitis of 1.3/100p-y; over five years, uveitis was associated with dactylitis, biologic and sacro iliac MRI inflammation.

Development and validation of a flax (Linum usitatissimum L.) gene expression oligo microarray.

BACKGROUND: Flax (Linum usitatissimum L.) has been cultivated for around 9,000 years and is therefore one of the oldest cultivated species. Today, flax is still grown for its oil (oil-flax or linseed cultivars) and its cellulose-rich fibres (fibre-flax cultivars) used for high-value linen garments and composite materials. Despite the wide industrial use of flax-derived products, and our actual understanding of the regulation of both wood fibre production and oil biosynthesis more information must be acquired in both domains. Recent advances in genomics are now providing opportunities to improve our fundamental knowledge of these complex processes. In this paper we report the development and validation of a high-density oligo microarray platform dedicated to gene expression analyses in flax. RESULTS: Nine different RNA samples obtained from flax inner- and outer-stems, seeds, leaves and roots were used to generate a collection of 1,066,481 ESTs by massive parallel pyrosequencing. Sequences were assembled into 59,626 unigenes and 48,021 sequences were selected for oligo design and high-density microarray (Nimblegen 385K) fabrication with eight, non-overlapping 25-mers oligos per unigene. 18 independent experiments were used to evaluate the hybridization quality, precision, specificity and accuracy and all results confirmed the high technical quality of our microarray platform. Cross-validation of microarray data was carried out using quantitative qRT-PCR. Nine target genes were selected on the basis of microarray results and reflected the whole range of fold change (both up-regulated and down-regulated genes in different samples). A statistically significant positive correlation was obtained comparing expression levels for each target gene across all biological replicates both in qRT-PCR and microarray results. Further experiments illustrated the capacity of our arrays to detect differential gene expression in a variety of flax tissues as well as between two contrasted flax varieties. CONCLUSION: All results suggest that our high-density flax oligo-microarray platform can be used as a very sensitive tool for analyzing gene expression in a large variety of tissues as well as in different cultivars. Moreover, this highly reliable platform can also be used for the quantification of mRNA transcriptional profiling in different flax tissues.

Emerging Roles of Perivascular Mesenchymal Stem Cells in Synovial Joint Inflammation.

In contrast to the significant advances in our understanding of the mesenchymal stem cell (MSC) populations in bone marrow (BM), little is known about the MSCs that are resident in the synovial joint and their possible roles in the tissue homeostasis, chronic inflammation as well as in repair. Neural crest is a transient embryonic structure, generating multipotential MSC capable of migrating along peripheral nerves and blood vessels to colonize most tissue types. In adult, these MSC can provide functional stromal support as a stem cell niche for lymphocyte progenitors for instance in the BM and the thymus. Critically, MSC have major immunoregulatory activities to control adverse inflammation and infection. These MSC will remain associated to vessels (perivascular (p) MSC) and their unique expression of markers such as myelin P0 and transcription factors (e.g. Gli1 and FoxD1) has been instrumental to develop transgenic mice to trace the fate of these cells in health and disease conditions. Intriguingly, recent investigations of chronic inflammatory diseases argue for an emerging role of pMSC in several pathological processes. In response to tissue injuries and with the release of host cell debris (e.g. alarmins), pMSC can detach from vessels and proliferate to give rise to either lipofibroblasts, osteoblasts involved in the ossification of arteries and myofibroblasts contributing to fibrosis. This review will discuss currently available data that suggest a role of pMSC in tissue homeostasis and pathogenesis of the synovial tissue and joints. Graphical abstract.

1H-NMR-Based Analysis for Exploring Knee Synovial Fluid Metabolite Changes after Local Cryotherapy in Knee Arthritis Patients.

Rehabilitation using cryotherapy has widely been used in inflammatory diseases to relieve pain and decrease the disease activity. The aim of this study was to explore the metabolite changes in inflammatory knee-joint synovial fluids following local cryotherapy treatment (ice or cold CO2). We used proton nuclear magnetic resonance (1H NMR) spectroscopy to assess the metabolite patterns in synovial fluid (SF) in patients with knee arthritis (n = 46) before (D0) and after (D1, 24 h later) two applications of local cryotherapy. Spectra from aqueous samples and organic extracts were obtained with an 11.75 Tesla spectrometer. The metabolite concentrations within the SF were compared between D1 and D0 using multiple comparisons with the application of a false discovery rate (FDR) adjusted at 10% for each metabolite. A total of 32 metabolites/chemical structures were identified including amino acids, organic acids, fatty acids or sugars. Pyruvate, alanine, citrate, threonine was significantly higher at D1 vs D0 (p < 0.05). Tyrosine concentration significantly decreases after cryotherapy application (p < 0.001). We did not observe any effect of gender and cooling technique on metabolite concentrations between D0 and D1 (p > 0.05). The present study provides new insight into a short-term effect of cold stimulus in synovial fluid from patients with knee arthritis. Our observations suggest that the increased level of metabolites involved in energy metabolism may explain the underlying molecular pathways that mediate the antioxidant and anti-inflammatory capacities of cryotherapy.

Microwave-Assisted versus Conventional Isolation of Glucosinolate Degradation Products from Lunaria annua L. and Their Cytotoxic Activity.

Glucosinolates (GSLs) from Lunaria annua L. seeds were analyzed qualitatively and quantitatively by their desulfo counterparts using UHPLC-DAD-MS/MS technique and by their volatile breakdown products, isothiocyanates (ITCs), using GC-MS technique. GSL breakdown products were obtained by conventional techniques (hydrodistillation in a Clevenger type apparatus (HD), CH2Cl2 extraction after myrosinase hydrolysis (EXT) for 24 h) as well as by modern techniques, microwave-assisted distillation (MAD) and microwave hydrodiffusion and gravity (MHG). Seven GSLs were identified as follows: isopropyl GSL (1), sec-butyl GSL (2), 5-(methylsulfinyl)pentyl GSL (3), 6-(methylsulfinyl)hexyl GSL (4), 5-(methylsulfanyl)pentyl GSL (5), 6-(methylsulfanyl)hexyl GSL (6), and benzyl GSL (7). Additionally, pent-4-enyl- and hex-5-enyl ITCs were detected in the volatile extracts. However, their corresponding GSLs were not detected using UHPLC-DAD-MS/MS. Thus, they are suggested to be formed during GC-MS analysis via thermolysis of 5-(methylsulfinyl)pentyl- and 6-(methylsulfinyl)hexyl ITCs, respectively. Volatile isolates were tested for their cytotoxic activity using MTT assay. EXT and MHG showed the best cytotoxic activity against human lung cancer cell line A549 during an incubation time of 72 h (IC50 18.8, and 33.5 µg/mL, respectively), and against breast cancer cell line MDA-MB-231 after 48 h (IC50 6.0 and 11.8 µg/mL, respectively). These activities can be attributed to the ITCs originating from 3 and 4.

Effect of Gut Involvement in Patients with High Probability of Early Spondyloarthritis: Data from the DESIR Cohort.

OBJECTIVE: Inflammatory bowel disease (IBD) is a well-known extraarticular feature of spondyloarthritis (SpA). The aims of this study were to evaluate factors associated with IBD and incidence over 5 years of followup in the DESIR cohort. METHODS: DESIR is a prospective observational cohort of patients with recent-onset inflammatory back pain suggestive of axial SpA. All available variables in the database were compared between patients with and without IBD at baseline and 5 years, and occurrence over 5 years of followup, with uni- and then multivariable analysis. RESULTS: At baseline, of 708 patients, 35 had IBD (prevalence 4.94%, CI 95% 3.3-6.5). IBD was associated (multivariable) with history of uveitis, levels of Dickkopf-1, and tumor necrosis factor, but not with phenotypic presentation (peripheral arthritis, enthesitis, dactylitis, uveitis) or baseline serum levels of other cytokines. At 5 years, 480 patients were analyzed, 58 with IBD. IBD was associated (multivariable) with fulfillment of modified New York criteria, sick leave, Bath Ankylosing Spondylitis Disease Activity Index, and smoking. There was no association with magnetic resonance imaging scores, enthesitis, psoriasis, and bone mineral density. Twenty-three incident cases of IBD were recorded: estimated occurrence rate of 0.95/100 (95% CI 0.57-1.35) patient-years (PY). Incidence of IBD is associated (multivariable) with HLA-B27 (OR 0.36, 95% CI 0.22-0.59), fulfillment of modified New York criteria (OR 3.35, 95% CI 1.85-6.08), and familial history of IBD (OR 3.31, 95% CI 1.62-6.77). CONCLUSION: In early SpA, IBD occurs with an incidence of 1/100 PY, and is associated with poor outcome, familial history of IBD, absence of HLA-B27, and fulfillment of modified New York criteria.