Effect of synthethic drugs inhibiting tumor necrosis factor alpha on the experimental arthritis in rats

A artrite reumatoide (AR) é uma doença autoimune, inflamatória, crônica, sistêmica e de etiologia desconhecida que pode ser induzida experimentalmente em animais por administração de colágeno e adjuvante (CIA). Os medicamentos biológicos contra o fator de necrose tumoral (TNF)-α são indicações terapêuticas atualmente consolidadas para os casos mais severos de AR. As limitações ao uso dessa classe de medicamentos têm sido o alto custo e a dificuldade em fabricar genéricos ou similares com composição, qualidade e desempenho equivalentes na mesma dose e via de administração. O presente estudo avaliou a hipótese de que drogas sintéticas que inibam a produção de TNF-α e / ou fatores relacionados teriam potencial para tornarem-se terapias complementares ou alternativas eficientes para esta doença. Para isso, foram utilizados ratos submetidos ao modelo CIA e tratados cronicamente com pentoxifilina (PTX), rolipram (ROL), talidomida (TAL) e rupatadina (RUP). Um tratamento com prednisolona (PRED) foi também efetuado para avaliar sua influência na eventual ação antiartrítica de PTX, ROL, TAL e RUP, de modo a mimetizar seu efeito imunossupressor, quando administrada agudamente (AG) antes de medicamentos biológicos, bem como pelo seu conhecido efeito anti-inflamatório, quando administrada cronicamente (CR) no tratamento da AR. O desenvolvimento da AR e a efetividade dessas drogas sobre a AR foram avaliadas, de forma seletiva e sequencial, por meio da detecção de eritema e cianose, bem como medidas de edema, massa corporal, hemograma, TNF-α no plasma, fator reumatoide (FR) e anticorpo antinuclear (ANA) no soro, interleucina (IL)-1β e IL-6 no soro e líquido sinovial, atividade de aminopeptidase básica (APB) na fração solúvel (FS) do tecido sinovial (TS) e de células mononucleares do sangue periférico (PBMCs), densitometria óssea e análise histológica. A hepatotoxicidade dessas drogas foi avaliada pelas medidas de alanina-transaminase (ALT) e aspartato-transaminase (AST) no plasma. A AR caracterizou-se pelo aumento de TNF-α plasmático e de IL-1β e IL-6 no líquido sinovial, alterações histológicas na articulação tíbio-tarsal, bem como edema, cianose, eritema, diminuição de linfócitos e atividade APB de FS aumentada no TS e diminuída em PBMCs. A AR aumentou ALT e AST. O tratamento com PRED crônico promoveu um efeito antiedematogênico. O coquetel (MIX de PTX+ROL+RUP+TAL) também apresentou efeito antiedematogênico. A administração concomitante de PRED AG ou PRED CR com MIX não produziu sinergismo ou potenciação do efeito antiedematogênico da administração isolada do MIX ou da PRED crônica. Além do MIX, ROL e TAL diminuíram o edema. MIX, ROL e TAL melhoraram TNF-α no plasma e APB na FS do TS e não causaram hepatotoxicidade, tal como refletido nos níveis de ALT e AST. TAL recuperou ALT e AST, sem alteração do hemograma. Uma vez que PTX e RUP não apresentaram efeito antiedematogênico, ROL e TAL foram hipotetizados como os prováveis responsáveis pela atividade antiartrítica do MIX. Então, os tratamentos com ROL, TAL e ROL+TAL foram selecionados para avaliação da histologia óssea e medidas de parâmetros diferenciais entre animais controles sadios e artríticos. Esta avaliação mostrou que o tratamento isolado da AR com ROL ou TAL não alterou IL-6, mas recuperou IL-1β no líquido sinovial, efeitos esses que não se diferenciaram do tratamento combinado de ROL+TAL, exceto pelo fato de que essa combinação também diminuiu a massa corporal. TAL se destacou por seu efeito hepatoprotetor nos animais AR. Considerando os efeitos conhecidos de RUP, PTX, TAL e ROL é possível hipotetizar que a ação antiartrítica de TAL e ROL deve-se à inibição da síntese de TNF-α decorrente da inibição de PDE4 em suas principais fontes celulares. Os dados deste estudo prospectivo fornecem subsídios adicionais que estimulam a realização de novos ensaios clínicos, mais amplos e sistematizados, sobre os efeitos antiartríticos de ROL e TAL. Conclui-se que o uso isolado de TAL emerge como uma alternativa terapêutica econômica, simples e eficaz para a AR, enquanto a combinação de ROL+TAL pode ser uma opção viável para portadores de AR com sobrepeso ou obesidadeRheumatoid arthritis (RA) is an autoimmune, inflammatory, chronic and systemic disease with unknown etiology that can be experimentally induced in animals by administration of collagen and adjuvant (CIA). Biological drugs against tumor necrosis factor (TNF)- α are therapeutic indications currently consolidated for the most severe cases of RA. The limitations for the use of this class of drugs have been the high cost and the difficulty to manufacture a generic or similar ones with equivalent composition, quality and performance under the same dosage and route of administration. The present study evaluated the hypothesis that synthetic drugs that inhibit the production of TNF-α and/or related factors would have potential to become efficient complementary or alternative therapies for this disease. For this purpose, male rats submitted to the CIA model were chronically treated with pentoxifylline (PTX), rolipram (ROL), thalidomide (TAL) and rupatadine (RUP). The treatment with prednisolone (PRED) was also performed to evaluate its influence on the possible antiarthritic action of PTX, ROL, TAL and RUP, in order to mimic its immunosuppressive effect when acutely (AG) administered prior to biological drugs, as well as due to its known anti-inflammatory effect when administered chronically (CR) to treat RA. The development of RA and the efficacy of these drugs on RA were evaluated, by selective and sequential ways, through the detection of erythema and cyanosis, as well as measurements of edema, body mass, hemogram, plasma TNF-α, rheumatoid factor (FR) and anti-nuclear antibody (ANA) in serum, interleukin (IL)-1β and IL-6 in serum and synovial fluid, basic aminopeptidase activity (APB) in soluble fraction (FS) from synovial tissue (TS) and from peripheral blood mononuclear cells (PBMCs), bone densitometry and histological analysis. The hepatotoxicity of these drugs was evaluated by measurements of alanine-transaminase (ALT) and aspartate-transaminase (AST). RA was characterized by increased TNF-α in plasma and IL-1β and IL-6 in synovial fluid, histological alterations in the tibio-tarsal joint, as well as edema, cyanosis, erythema, decreased lymphocyte number and increased APB activity in TS and decreased APB activity in PBMCs. RA produced increased ALT and AST. As expected, the chronic treatment with PRED promoted an antiedematogenic effect. The cocktail (MIX of PTX+ROL+RUP+TAL) also presented antiedematogenic effect. Concomitant administration of acute or chronic PRED with MIX did not produce synergism or potentiation of the antiedematogenic effect due to the single administration of MIX or chronic PRED. In addition to MIX, ROL and TAL were also antiedematogenic. MIX, ROL and TAL ameliorated plasma TNF-α and APB in FS from TS without hepatotoxicity, as reflected by ALT and AST levels. TAL recovered ALT and AST, but it did not affect the hemogram. Since PTX and RUP did not present antiedematogenic effects, ROL and TAL were hypothesized as probable responsible for the antiarthritic activity of MIX. Thus, the treatments with ROL, TAL and ROL+TAL were selected for evaluation of bone histology and measurements of differential parameters between healthy control and arthritic animals. This evaluation showed that the treatment of RA with ROL or TAL alone did not alter IL-6 levels, but recovered IL-1β in the synovial fluid. Both these effects were not different from those of the concomitant treatment with ROL+TAL, except that this combination also decreases the body mass. TAL stands out for its hepatoprotective effect in RA animals. Considering the known effects of RUP, PTX, TAL and ROL it can be hypothesized that antiarthritic action of TAL and ROL is due to the inhibition of TNF-α synthesis as consequence of its inhibition in its main cellular sources by PDE4. Data from this prospective study provide additional subsidies that stimulate further and more comprehensive clinical trials on the antiarthritic effects of ROL and TAL. In conclusion, the treatment with TAL alone emerges as an economical, simple and effective therapeutical alternative for RA, while the combination of ROL+TAL can be a viable option for RA sufferers with overweight or obesit

Basic aminopeptidase and Leukotriene-A4-hydrolase of rats sensitive and insensitive to induction of arthritis by type-II collagen

Atualmente, ainda é incerto se a hidrólise de L-arginil-β-naftilamida (ArgNA) e do leucotrieno (LT) A4 pela LT-A4-hidrolase (LT-A4-H) (EC 3.3.2.6) e pela aminopeptidase básica (APB) (EC 3.4.11.6) tem influência no desenvolvimento da artrite induzida por colágeno (CIA). O objetivo deste estudo foi investigar a inter-relação entre LT-A4-H, APB e LT-B4 em ratos submetidos à CIA. Cromatografia líquida de alta eficiência (HPLC), ensaio imunoenzimático (EIA), espectrofluorimetria e reação quantitativa em tempo real em cadeia da polimerase (qPCR) foram usados como metodologias. A existência dos genes para as proteínas EC 3.3.2.6 e EC 3.4.11.6 foi confirmada no tecido sinovial (TS) de ratos controles sadios. A hidrólise de ArgNA aumentou na fração solúvel (FS) dos animais submetidos à CIA que desenvolveram a doença (artríticos-CIA) em comparação com aqueles que não desenvolveram a doença (resistentes-CIA) e com os controles sadios. No líquido sinovial (SY) e no plasma sanguíneo houve menor hidrólise de ArgNA em resistentes em comparação aos artríticos e controles. Nas células mononucleares do sangue periférico (PBMCs), os níveis de hidrólise de ArgNA aumentaram na FS de controles e na fração de membrana (FM) dos resistentes em comparação aos artríticos. Em comparação com controles sadios, a hidrólise de LT-A4 aumentou no SY e na FS de PBMCs de artríticos e resistentes. A hidrólise de LT-A4 também aumentou na FM do TS de resistentes e diminuiu na FM de PBMCs em artríticos e resistentes. Em todos estes compartimentos a hidrólise de ArgNA permaneceu inalterada ou relacionou-se inversamente com a hidrólise de LT-A4, comparativamente aos controles sadios. A hidrólise de ArgNA diferiu entre os artríticos e resistentes em FM-TS, FS-TS, FM-PBMCs, SY e no plasma sanguíneo. Uma relação no mesmo sentido foi encontrada entre alterações na hidrólise de LT-A4 e nos níveis de LT-B4 apenas em SY e FM-PBMCs dos artríticos e resistentes e em FM-TS dos resistentes, comparativamente aos controles sadios. Em conclusão, a atividade APB é um novo marcador que distingue ratos artríticos e resistentes no modelo CIA. Os níveis de LT-B4 em ratos não são controlados somente pela LT-A4-H. Alterações na atividade LT-A4-H e nos níveis de LT-B4 são indistinguíveis entre artríticos e resistentes, mas tais alterações marcadamente distinguem essas duas condições da condição saudável. LT-A4-H e APB estão relacionadas de uma forma compartimento-dependente, atuando como enzimas independentes, com modulação diferencial das suas especificidades, eficiências e/ou afinidades catalíticas sobre os substratos epóxi e peptídico, ou como enzimas bifuncionais, cujas atividades são inversamente relacionadas devido à inibição concorrente de uma destas atividadesWhether L-arginyl-β-naphthylamide (ArgNA) and leukotriene (LT)-A4 hydrolyses by LT-A4 hydrolase (LT-A4-H) (EC 3.3.2.6) and basic aminopeptidase (APB) (EC 3.4.11.6) influence the development of collagen-induced arthritis (CIA) is presently uncertain. The objective of this study was to investigate the interrelationship among LT-A4-H, APB and LT-B4 in CIA rats. High-performance liquid chromatography (HPLC), enzyme immunoassay (EIA), spectrofluorometry and quantitative real time polymerase chain reaction (qPCR) were used as methodologies. The existence of genes for EC 3.3.2.6 and EC 3.4.11.6 proteins were confirmed in the synovial tissue (TS) of healthy control rats. ArgNA hydrolysis was higher in soluble fraction (FS) in rats submitted to CIA that developed the disease (CIA-arthritic) than in those that did not develop the disease (CIA-resistant) or healthy control. Synovial fluid (SY) and blood plasma had lower ArgNA hydrolysis in CIA-resistant than in CIA-arthritic or control. In the peripheral blood mononuclear cells (PBMCs) the levels of ArgNA hydrolysis increased in FS of control and in membrane-bound fraction (FM) of CIA-resistant in comparison with CIA-arthritic. Compared with healthy control, LT-A4 hydrolysis increased in SY and in FS from PBMCs of CIA-arthritic and CIA-resistant. LT-A4 hydrolysis also increased in FM from TS of CIA-resistant and decreased in PBMCs-FM of CIA-arthritic and CIA-resistant. In all these locations hydrolysis of ArgNA remained unchanged or it was inversely related with LT-A4 hydrolysis, comparatively to healthy control. ArgNA hydrolysis differed between CIA-arthritic and CIA-resistant in TS-FM, TS-FS, PBMCs-FM, SY and blood plasma. A same-sense relationship was found between changes on LT-A4 hydrolysis and LT-B4 levels only in SY and PBMCs-FM of CIA-arthritic and CIA-resistant and in TS-FM of CIA-resistant, comparatively to healthy control. In conclusion, the APB activity is a novel distinctive marker of CIA-arthritic and CIA-resistant statuses. The levels of LT-B4 in rats are not controlled only by LT-A4-H. Changes on LT-A4-H activity and LT-B4 levels are indistinguishable between CIA-resistant and CIA-arthritic, but such variations markedly distinguish these two statuses from healthy status. LT-A4-H and APB are related in a compartment-dependent manner acting as independent enzymes with differential modulation of their specificity, efficiency and/or catalytic affinity on the aminoacyl and epoxy substrates, or as bifunctional enzymes which activities are inversely related due to the concurrent inhibition of one of thes

The Interrelationship between Leukotriene B4 and Leukotriene-A4-Hydrolase in Collagen/Adjuvant-Induced Arthritis in Rats

This study aimed to check the involvement of lipid mediator leukotriene (LT) B4 and the activity of LTA4 hydrolase (LTA4H) in the development of arthritis induced in rats by collagen and adjuvant (CIA). High-performance liquid chromatography (HPLC) and enzyme immunoassay (EIA) were used for measurements of LTB4 and LTA4H in plasma, synovial fluid (SF), soluble (SO), and solubilized membrane-bound fraction (MB) from synovial tissue (ST) and peripheral blood mononuclear cells (PBMCs) of CIA-arthritic and CIA-resistant. EIA process is simple, clean, and rapid and offered advantages over HPLC, showing that in SF and MB-PBMCs of CIA-arthritic and CIA-resistant, and in MB-ST of CIA-resistant, LTB4 and LTA4H were altered in parallel and were positively related. In the plasma and SO-ST and SO-PBMCs of CIA-arthritic and CIA-resistant, and in MB-ST of CIA-arthritic, this pattern was not found. The primordial role played by LTA4H in the biosynthesis of LTB4 was confirmed together with the existence of alternative steps that regulate LTB4 without participation of LTA4H. The involvement of compartmentalized and coupled changes of LTB4 and LTA4H in the resistance and development of arthritis in CIA model was demonstrated for the first time

APM/CD13 and FOS in the hypothalamus of monosodium glutamate obese and food deprived rats

Protein (western blotting) and gene (PCR) expressions, catalytic activity of puromycin-insensitive membrane-bound neutral aminopeptidase (APM/CD13) and in situ regional distribution of CD13 and FOS immunoreactivity (it) were evaluated in the hypothalamus of monosodium glutamate obese (MSG) and/or food deprived (FD) rats in order to investigate their possible interplay with metabolic functions. Variations in protein and gene expressions of CD13 relative to controls coincided in the hypothalamus of MSG and MSG-FD (decreased 2- to 17-fold). Compared with controls, the reduction of hypothalamic CD13 content reflected a negative balance in its regional distribution in the supraoptic, paraventricular, periventricular and arcuate nuclei. CD13-ir increased in the supraoptic nucleus in MSG (2.5-fold) and decreased in the paraventricular nucleus (2-fold) together with FOS-ir (1.5-fold) in FD. In MSG-FD. FOS-ir decreased (7-fold) in the paraventricular nucleus, while CD13-ir decreased in the periventricular (5.6-fold) and the arcuate (3.7-fold) nuclei. It was noteworthy that all these changes of CD13 were not related to catalytic activity of APM. Data suggested that hypothalamic CD13 plays a role in the regulation of energy metabolism not by means of APM enzyme activity. (c) 2010 Elsevier B.V. All rights reserved.FAPESP (Fundacao de Amparo a Pesquisa do Estado de Sao Paulo, Brazil)[05/04699-2]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CNPq (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico, Brazil)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CNP

Basic aminopeptidase activity is an emerging biomarker in collagen-induced rheumatoid arthritis

The objective of this study was to investigate the catalytic activity of basic aminopeptidase (APB) and its association with periarticular edema and circulating tumor necrosis factor (TNF)-alpha and type II collagen (CII) antibodies (AACII) in a rat model of rheumatoid arthritis (RA) induced by CII (CIA). Edema does not occur in part of CH-treated, even when AACII is higher than in control. TNF-alpha is detectable only in edematous CII-treated. APB in synovial membrane is predominantly a membrane-bound activity also present in soluble form and with higher activity in edematous than in non-edematous CH-treated or control. Synovial fluid and blood plasma have lower APB in non-edematous than in edematous CII-treated or control. In peripheral blood mononuclear cells (PBMCs) the highest levels of APB are found in soluble form in control and in membrane-bound form in non-edematous CII-treated. CII treatment distinguishes two categories of rats: one with arthritic edema, high AACII, detectable TNF-alpha, high soluble and membrane-bound APB in synovial membrane and low APB in the soluble fraction of PBMCs, and another without edema and with high AACII, undetectable TNF-alpha, low APB in the synovial fluid and blood plasma and high APB in the membrane-bound fraction of PBMCs. Data suggest that APB and CIA are strongly related. (C) 2011 Elsevier B.V. All rights reserved.FAPESP (Fundacao de Amparo a Pesquisa do Estado de Sao Paulo, Brazil)[09/17613-0]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)CNPq (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico, Brazil)[301417/2008-3]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)CAPES (Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior, Brazil