Exercise in Takayasu Arteritis: Effects on Inflammatory and Angiogenic Factors and Disease-Related Symptoms.

OBJECTIVE: To investigate the effects of acute and chronic exercise in female patients with remissive Takayasu arteritis (TAK). METHODS: This was a 2-part prospective study. In study 1, cytokines and soluble tumor necrosis factor (TNF) receptors were assessed at rest and every 60 minutes during a 3-hour recovery period following an acute exercise session in TAK (n = 11) and heathy control (n = 10) groups. In study 2, a subsample from the TAK group (n = 6) underwent a 12-week exercise training program. Before and after training, the acute session of aerobic exercise was performed and cytokines and soluble TNF receptors were assessed at the same time points described above. Muscle function, strength, aerobic capacity, endothelial function, quality of life, and walking impairment scores were evaluated. RESULTS: In study 1, the acute session of aerobic exercise led to overall similar responses on cytokine kinetics in the TAK and heathy control groups. In study 2, the exercise training program did not exacerbate inflammatory cytokines in TAK patients, while the proinflammatory cytokine TNF was diminished both at rest and following the acute session of aerobic exercise. In addition, the exercise training program increased the pro-angiogenic factors vascular endothelial growth factor (at rest) and platelet-derived growth factor AA (at rest and in response to the acute session of aerobic exercise). The exercise training program improved muscle strength and function, whereas aerobic capacity, quality of life, and endothelial function parameters remained unchanged. CONCLUSION: Exercise could be a well-tolerated, safe, and effective intervention able to induce immunomodulatory and pro-angiogenic effects and to increase strength and function in patients with TAK.

Anti-inflammatory effects of intravenous methotrexate associated with lipid nanoemulsions on antigen-induced arthritis.

OBJECTIVE: To test the hypothesis that intravenous use of methotrexate associated with lipid nanoemulsions can achieve superior anti-inflammatory effects in the joints of rabbits with antigen-induced arthritis compared with commercial methotrexate. METHODS: Arthritis was induced in New Zealand rabbits sensitized with methylated bovine serum albumin and subsequently intra-articularly injected with the antigen. A nanoemulsion of methotrexate labeled with 3H-cholesteryl ether (4 mg/kg methotrexate) was then intravenously injected into four rabbits to determine the plasma decaying curves and the biodistribution of the methotrexate nanoemulsion by radioactive counting. Additionally, the pharmacokinetics of the methotrexate nanoemulsion were determined by high-pressure liquid chromatography. Twenty-four hours after arthritis induction, the animals were allocated into three groups, with intravenous injection with saline solution (n=9), methotrexate nanoemulsion (0.5 µmol/kg methotrexate, n=7), or commercial methotrexate (0.5 µmol/kg, n=4). The rabbits were sacrificed 24 h afterward. Synovial fluid was then collected for protein leakage and cell content analyses and synovial membranes were collected for histopathological analysis. RESULTS: The methotrexate nanoemulsion was taken up mainly by the liver and the uptake by arthritic joints was two-fold greater than that by control joints. The methotrexate nanoemulsion treatment reduced leukocyte influx into the synovial fluid by nearly 65%; in particular, mononuclear and polymorphonuclear cells were reduced by 47 and 72%, respectively. In contrast, cell influx was unaffected following treatment with commercial methotrexate. Protein leakage into the arthritic knees of the rabbits was also more limited following methotrexate nanoemulsion treatment than following commercial methotrexate treatment. CONCLUSIONS: The intravenous methotrexate nanoemulsion showed anti-inflammatory effects on the synovia of arthritic joints that were clearly superior to the effects of a commercial methotrexate preparation. This result is conceivably due to greater methotrexate uptake by the joints when the drug is associated with a nanoemulsion.

Intra-articular methotrexate associated to lipid nanoemulsions: anti-inflammatory effect upon antigen-induced arthritis.

OBJECTIVE: Commercial methotrexate formulations (MTX) have poor anti-inflammatory action for intra-articular treatment of rheumatoid arthritis. Our aim was to investigate whether an association between methotrexate and lipidic nanoemulsions (LDE) could improve MTX intra-articular action. METHODS: For its association to LDE, MTX was previously esterified with dodecyl bromide. LDE-MTX was prepared by high pressure homogenization. Antigen-induced arthritis (AIA) was achieved in rabbits sensitized with methylated bovine serum albumin, and the rabbits were subsequently intra-articularly injected with the antigen. Twenty-four hours after AIA induction, groups of four to nine rabbits were intra-articularly injected with increasing doses (0.0625-0.5 µmol/kg) of LDE-MTX, and were compared to treatment with 0.5 µmol/kg commercial MTX, LDE alone, and saline (controls). Synovial fluid was collected 48 hours after AIA induction for analysis of protein leakage and cell content. Synovial membranes were collected for histopathology. Uptake of LDE labeled with (3)H-cholesteryl ether by the synovial tissue was also determined. RESULTS: Uptake of radioactive LDE by arthritic joints was 2.5-fold greater than by normal joints. Treatment with intra-articular LDE-MTX elicited a clear dose response pattern by reducing the synovial leukocyte infiltrate (P = 0.004) and protein leakage (P = 0.032) when compared with arthritic non-treated joints. In contrast, the intra-articular injection of commercial MTX and LDE did not reduce leukocyte infiltrate or protein leakage. Toxicity to treatment was not observed in any of the animals. CONCLUSION: The association between LDE and MTX presented a marked anti-inflammatory effect that was absent after intra-articular commercial MTX treatment. Therefore, the new formulation is a candidate for future clinical studies.

In vivo blockade of Ca(+2)-dependent nitric oxide synthases impairs expressions of L-selectin and PECAM-1.

Interactions of leukocytes with endothelium play a role for the immune system modulated by endogenous agents, such as glucocorticoids and nitric oxide (NO). Glucocorticoids inhibit leukocyte-endothelial interactions whereas the role of NO is still controversial. In this study, the activity of Ca(+2)-dependent nitric oxide synthases was in vivo blocked in male Wistar rats by given l-NAME, 20mgkg(-1) for 14 days dissolved in drinking water and expression of adhesion molecules involved in leukocyte-endothelial interactions was investigated. Expressions of L-selectin and PECAM-1 in peripheral leukocytes and PECAM-1 in endothelial cells were reduced by l-NAME treatment. Only L-selectin expression was controlled at transcriptional levels. These effects were not dependent on endogenous glucocorticoids, as corticosterone levels were not altered in l-NAME-treated rats. Our results show that NO, produced at physiological levels, controls expression of constitutive adhesion molecules expressions in cell membranes by different mechanisms of action.

Interleukin 18 as a marker of disease activity and severity in patients with juvenile idiopathic arthritis.

OBJECTIVE: To verify the importance of interleukin 18 (IL-18) in the pathogenesis of juvenile idiopathic arthritis (JIA). We measured IL-18 levels in synovial fluid (SF) and serum, and determined their correlation with measures of disease activity and severity. METHODS: Fifty patients with JIA (13 systemic, 13 polyarticular, 24 oligoarticular) and 25 matched controls were analyzed. Cytokine levels (IL-1beta, IL-1Ra, IL-6, and IL-18) were quantified in serum and SF by ELISA, and disease activity measures were evaluated immediately after knee articular puncture. Radiological assessment was made according to the Steinbrocker method. Statistical analysis was performed by Spearman's rank-order correlation and Mann-Whitney rank test. RESULTS: All the analyzed cytokine levels (IL-1, IL-1Ra, IL-6, and IL-18) were higher in patients' sera than in controls. Remarkably, in patients with JIA, IL-18 SF levels did not differ from those of serum; they were positively correlated. The levels of IL-18 (SF and serum) were positively correlated with measures of disease activity: C-reactive protein, number of active joints, and radiological score, as well as with levels of IL-1, IL-1Ra, and IL-6. Moreover, IL-18 and IL-6 levels in SF and serum were much higher in patients with systemic disease compared to the other types of disease onset. In contrast, IL-1 and IL-1Ra were not different among JIA subtypes. CONCLUSION: Our results strongly suggest the participation of IL-18 in the pathophysiology of JIA. The positive correlation of this cytokine with several measures of articular inflammation and disease severity suggests that IL-18 could be a better target for the treatment of arthritis.

Pro and antiinflammatory properties of toxins from animal venoms.

Accidents evoked by venomous animals are common in tropical regions. In Brazil, envenomation evoked by snakes, spiders and scorpions are an important public health problem. Their venoms are composed of a great number of toxins, which are capable of acting on tissue and plasma components with consequent toxic and pharmacological effects. On the other hand, the diversity of venom composition makes them important source of toxins that can be employed as scientific tools. Here we describe the mechanisms of anti and pro-inflammatory properties of toxins of Bothrops and Crotalus genus snakes and Loxosceles and Phoneutria genus spider venoms. The emphasis was to summarise, both in vivo and in vitro, studies that focused on the action of phospholipases, metalloproteinases and sphingomyelinase D on vascular and cellular aspects of the process as well as the complex network of chemical mediators involved.

Pharmacological characterisation of arthritis induced by Bothrops jararaca venom in rabbits: a positive cross talk between bradykinin, nitric oxide and prostaglandin E2.

BACKGROUND: Our previous results showed that nitric oxide (NO) and bradykinin (BK) mediate the arthritis induced by Bothrops jararaca venom (BjV) in rabbits. In this study, we investigated the contribution of each receptor of BK as well as the inter-relationship between NO and eicosanoids in BjV-induced arthritis. METHODS: The arthritis was induced in rabbits with 16 microg of BjV injected intra-articularly. Prostaglandin E2 (PGE2), thromboxane B2 (TxB2), leukotriene B4 (LTB4) (radioimmunoassay) and nitrite/nitrate concentrations (NO2/NO3) (Griess reaction) were evaluated in the synovial fluid 4 h later. The animals were prior treated with NO synthase inhibitor (L-NAME; 20 mg/kg/day for 14 days), the B2 antagonist of BK (HOE-140) and the B1 antagonist of BK (des-Arg9[Leu8]-bradykinin), both at a dose of 0.3mg/kg, 30 min prior to the venom injection. RESULTS: Data show that L-NAME and HOE-140 treatment were equally able to reduce PGE2 and NO2/NO3 levels without interfering with TxB2 and LTB4 production. On the contrary, the B1 antagonist of BK inhibited TxB2 and LTB4 production, and did not alter PGE2 and NO metabolites levels in the inflamed joint. DISCUSSIONS: The results presented clarify the contribution of the kinin system, mainly through the B2 receptor, to the local inflammatory response induced by BjV, as well as its positive interaction with PGE2 and NO production.

Participaçäo de moléculas de adesäo no desenvolvimento da resposta inflamatória / Participation of the adhesion molecules in the development of inflammatory response

Os autores realizam uma revisäo sobre o papel de moléculas de adesäo sobre o desenvolvimento da resposta inflamatória, e mostram como a recente descriçäi dessas estruturas, expressas nas membranas dos leucócitos circulantes e da célula endotelial, têm esclarecido os processos de interaçäo leucócito-endotélio, fundamentais apra o recrutamento leucocitário. É discutido ainda, a açäo das principais drogas antiinflamatórias sobre a expressäo e funçäo dessas moléculas de adesäo e finalizando, é destacado o estudo de terapias anti-adesivas, como novas abordagens terapêuticas para o tratamento de doenças inflamatórias