Estrella Garcia-Gonzalez

Endothelial progenitor cells and colony-forming units in rheumatoid arthritis: association with clinical characteristics

OBJECTIVE To compare levels of a range of endothelial progenitor cells (EPCs) and endothelial colony-forming units (CFUs) in control participants and RA patients, in addition to verifying whether levels of EPCs or CFUs are associated with clinical characteristics in RA patients. METHODS Peripheral blood mononuclear cells (PBMCs) from 36 RA patients and 30 control participants were analysed by flow cytometry for EPCs defined by the expression of CD34/CD133, CD34/CD117, CD34/CD31, CD34/KDR and CD34/CD133/KDR. Endothelial cell colonies derived from culture of PBMCs were also assessed by CFU assay. RESULTS No differences in levels of EPCs were observed in RA patients compared with controls. However, levels of EPCs were negatively associated with prognostic markers of poor disease status, but not cardiovascular (CV)-related risk factors. Furthermore, the majority of EPCs examined were negatively correlated with levels of RF. In contrast, CFU number was significantly reduced in RA patients compared with controls and was negatively associated with CV risk factors only. CONCLUSION These findings indicate that more informative than comparing changes in absolute levels of EPCs, the examination of their relationship with clinical characteristics of RA patients can reveal significant associations, which may provide important clinical insights.

Adenosine A2A receptor activation stimulates collagen production in sclerodermic dermal fibroblasts either directly and through a cross-talk with the cannabinoid system

Systemic sclerosis (SSc) is a connective tissue disease characterised by exaggerated collagen deposition in the skin and visceral organs. Adenosine A2A receptor stimulation (A2Ar) promotes dermal fibrosis, while the cannabinoid system modulates fibrogenesis in vitro and in animal models of SSc. Moreover, evidence in central nervous system suggests that A2A and cannabinoid (CB1) receptors may physically and functionally interact. On this basis, we investigated A2Ar expression and function in modulating collagen biosynthesis from SSc dermal fibroblasts and analysed the cross-talk with cannabinoid receptors. In sclerodermic cells, A2Ar expression (RT-PCR, Western blotting) was evaluated together with the effects of A2A agonists and/or antagonists on collagen biosynthesis (EIA, Western blotting). Putative physical and functional interactions between the A2A and cannabinoid receptors were respectively assessed by co-immuno-precipitation and co-incubating the cells with the unselective cannabinoid agonist WIN55,212-2, and the selective A2A antagonist ZM-241385. In SSc fibroblasts, (1) the A2Ar is overexpressed and its occupancy with the selective agonist CGS-21680 increases collagen production, myofibroblast trans-differentiation, and ERK-1/2 phosphorylation; (2) the A2Ar forms an heteromer with the cannabinoid CB1 receptor; and (3) unselective cannabinoid receptor stimulation with a per se ineffective dose of WIN55,212-2, results in a marked anti-fibrotic effect after A2Ar blockage. In conclusion, A2Ar stimulation induces a pro-fibrotic phenotype in SSc dermal fibroblasts, either directly, and indirectly, by activating the CB1 cannabinoid receptor. These findings increase our knowledge of the pathophysiology of sclerodermic fibrosis also further suggesting a new therapeutic approach to the disease.

Cannabinoids inhibit fibrogenesis in diffuse systemic sclerosis fibroblasts

OBJECTIVE It has been demonstrated that the endocannabinoid system is up-regulated in pathologic fibrosis and that modulation of the cannabinoid receptors might limit the progression of uncontrolled fibrogenesis. The aim of this study was to investigate whether the synthetic cannabinoid receptor agonist WIN55,212-2 could modulate fibrogenesis in an in vitro model of dcSSc. METHODS The expression of cannabinoid receptors CB1 and CB2 was assessed in dcSSc fibroblasts and healthy control fibroblasts. To investigate the effect of WIN55,212-2 on dcSSc fibrogenesis, we studied type I collagen, profibrotic cytokines, fibroblast transdifferentiation into myofibroblasts, apoptotic processes and activation of the extracellular signal-related kinase 1/2 pathway prior to and after the treatment with the synthetic cannabinoid at increasing concentrations. RESULTS Both CB1 and CB2 receptors were over-expressed in dcSSc fibroblasts compared with healthy controls. WIN55,212-2 caused a reduction in extracellular matrix deposition and counteracted several behavioural abnormalities of scleroderma fibroblasts including transdifferentiation into myofibroblasts and resistance to apoptosis. The anti-fibrogenic effect of WIN55,212-2 was not reverted by selective cannabinoid antagonists. CONCLUSIONS Our preliminary findings suggest that cannabinoids are provided with an anti-fibrotic activity, thereby possibly representing a new class of agents targeting fibrosis diseases.

The cannabinoid WIN55, 212-2 abrogates dermal fibrosis in scleroderma bleomycin model

Objectives There is increasing evidence that the endocannabinoid system may be involved in pathological fibrosis, and that its modulation might limit fibrotic responses. The aim of this study was to examine the capacity of a synthetic cannabinoid receptor agonist to modify skin fibrosis in the bleomycin mouse model of scleroderma. Methods Skin fibrosis was induced by local injections of bleomycin in two groups of DBA/2J mice. One group was cotreated with the synthetic cannabinoid WIN55,212-2 at 1 mg/kg/day. Skin fibrosis was evaluated by histology and skin thickness and hydroxyproline content were quantified. Markers of fibroblast activation, including α smooth muscle actin and the profibrotic cytokines transforming growth factor (TGF)β, connective tissue growth factor (CTGF) and platelet-derived growth factor (PDGF)-BB, were examined. Levels of PSMAD2/3, which are crucial in extracellular matrix overproduction, were analysed. Results Bleomycin treatment induced typical skin fibrosis. Upon WIN55,212-2 treatment dermal fibrosis was completely prevented. Subcutaneous inflammatory cell infiltration, dermal thickness and collagen content resulted similar to those of the control group. The synthetic cannabinoid prevented fibroblasts activation induced by bleomycin, paralleled by a strong inhibition of TGFβ, CTGF and PDGF-BB expression. Phosphorylation of SMAD2/3 was significantly downregulated after WIN55,212-2 exposure. Conclusions Taken together, the results indicate that the synthetic cannabinoid WIN55,212-2 is capable of preventing skin fibrosis in a mouse model of scleroderma.

Crowned dens syndrome and cervical interspinous bursitis mimicking acute meningitis.

A 57-year-old woman presented to the emergency unit with neck pain of acute onset, stiffness, and fever. On admission, she was conscious. Physical examination revealed severe cervical rigidity with positive Kernig sign, but no focal neurological defects were present. A palpable and painful cervical mass was observed at the low cervical tract. Laboratory findings showed that C-reactive protein and erythrocyte sedimentation

Nodulite rhumatoïde bénigne

Revue du rhumatisme - In Press.Proof corrected by the author Available online since samedi 13 fevrier 2016

Benign rheumatoid nodulosis.

Joint Bone Spine - In Press.Proof corrected by the author Available online since samedi 14 mars 2015

SAT0032 The synthetic cannabinoid ajulemic acid exerts potent anti-fibrotic effects in experimental models of systemic sclerosis

Background Cannabinoids are able to modulate fibrogenesis in scleroderma. Ajulemic acid (AjA) is a non-psychoactive synthetic analogue of tetrahydrocannabinol (THC), able to bind the peroxisome proliferator-activated receptor-γ (PPAR-γ) (1). Recent evidence suggests a key role for PPAR-γ in fibrogenesis (2). Objectives We aimed to determine whether AjA can modulate fibrogenesis in murine models of scleroderma. Methods Bleomycin induced experimental fibrosis was used to assess the antifibrotic effects of AjA in-vivo. In addition, the efficacy of AjA in pre-established fibrosis was analyzed in a modified model of bleomycin-induced dermal fibrosis and in mice overexpressing a constitutively active transforming growth factor-β (TGF-β) receptor I (AdTGFbRI mice). Skin fibrosis was evaluated by quantification of skin thickness and hydroxyproline content. As a marker of fibroblast activation, α-smooth muscle actin (α-SMA) was examined. Results In acute model of experimental dermal fibrosis oral administration of AjA (1mg/kg/day) prevented development of skin fibrosis, and reduced skin thickness nearly to control levels. Consistently production of collagen, determined by quantification of dermal hydroxyproline content, was reduced substantially in mice treated with AjA. Treatment significantly reduced the number of myofibroblasts in lesional skin up to 26±5% (p<0.05). After eight weeks AdTGFbRI mice showed twofold increase in dermal thickness compared with Ad-Lac-z control mice (p<0.05). Oral administration of AjA (1mg/kg/day) for eight weeks reduced development of skin thickness up to 30±6% (mean±SD) compared to AdTGFbRI mice (p<0.05). AjA treatment (1mg/kg/day) induced a mean reduction of 30±13% (mean±SD) in hydroxyproline content (p<0.05). AjA treatment significantly reduced the number of myofibroblasts in lesional skin up to 26±3% (p<0.001). AjA effect in pre-established fibrosis, analyzed in a modified model of bleomycin-induced dermal fibrosis in the last 3 weeks, reduced collagen deposition by 10±8% (mean±SD) (p<0.05). Thus, AjA administration for the last 3 weeks of bleomycin challenge stopped further progression of fibrosis, but did not alter pre-existing ECM accumulation and dermal thickness.The number of myofibroblasts after AjA treatment was significantly reduced in lesional skin up to 25±16% (mean±SD) compared to bleomycin challenged mice (p<0.05). Conclusions We demonstrate that AjA prevents progression of fibrosis in-vivo and that inhibits fibrogenesis in-vitro by stimulating PPAR-γ signaling. Since therapeutic doses of AjA are well tolerated in humans, we suggest AjA as an interesting molecule targeting fibrosis in patients with scleroderma. References Burstein S. Ajulemic acid (IP-751): synthesis, proof of principle, toxicity studies, and clinical trials. AAPS J. 2005;7:143-8. Wei J, Ghosh AK, Sargent JL et al. PPARγ downregulation by TGFβ in fibroblast and impaired expression and function in systemic sclerosis: a novel mechanism for progressive fibrogenesis. PLoS One. 2010;5:e13778 Disclosure of Interest None Declared

An acutely swollen knee

A 77 year old retired man presented in a wheelchair to the emergency department with severe, constant pain and progressive swelling of the left knee. His symptoms had suddenly occurred two days before at night after he had gone to bed feeling well. He could not recall any injury to the knee. There was no history of joint disease or joint surgery. His medical history was unremarkable, and he was not taking any regular medication. He was not aware of any family history of arthritis. He smoked five cigarettes a day and drank two glasses of wine a day. On examination, the patient did not have a fever and had a heart rate of 82 beats/min and a blood pressure of 130/75 mm Hg. His body mass index was within normal limits. His left knee was red, hot, swollen, and tender with minimal range of motion. No other joint involvement was detected and there were no extra-articular findings. Synovial fluid was taken from the joint (fig 1⇓) and studied under compensated polarised light microscopy (fig 2⇓). A radiograph of the knee was also taken (fig 3⇓). All other system examinations were normal. Blood tests showed an erythrocyte sedimentation rate of 55 mm/h (normal <25 mm/h) and a C reactive protein concentration of 1.2 mg/dl (normal <0.5 mg/dl). Peripheral white blood cell count, platelet count, and haemoglobin concentration were within normal limits. Kidney and liver function parameters, and electrolytes and serum urate levels, were normal. Fig 1 Macroscopic appearance of the synovial fluid Fig 2 Wet preparation of the synovial fluid under compensated polarised light microscopy Fig 3 Radiograph of the left knee