RESUMEN
Although previous studies have demonstrated increased levels of the brain neurotransmitter glutamate (Glu) in the synovial fluid from patients with arthritis, not much attention has been paid to the possible role of Glu in joint synovial tissues to date. Constitutive expression of mRNA was for the first time shown with glutamate aspartate transporter, glutamate transporter-1 and excitatory amino acid carrier-1 (EAAC1), in addition to with particular ionotropic and metabotropic Glu receptors, in cultured synovial fibroblasts prepared from knee joints of male Lewis rats. Immunohistochemical analysis revealed high localization of immunoreactive EAAC1 at synovial tissues. The accumulation of [3H]Glu occurred in a temperature- and sodium-dependent manner in cultured synovial fibroblasts, with a Km of 23.1+/-1.1 microM and a Vmax of 237.1+/-31.1 pmol/(mg protein min), respectively. In rats with arthritis induced by immunization to type-II collagen, marked increases were seen in hind paw volume, cytokine mRNA expression and Glu levels in synovial tissues, in addition to histological erosion. In cultured synovial fibroblasts prepared from these arthritic rats, [3H]Glu accumulation was drastically increased with biochemical and pharmacological profiles similar to those seen in normal synovial fibroblasts. The exposure to Glu at 500 microM doubled the incorporation of 5-bromo-2'-deoxyuridine in cultured synovial fibroblasts of arthritic but not normal rats, without significantly affecting mRNA expression of different cytokines in both synovial fibroblasts. These results suggest that Glu may at least in part play a role in mechanisms associated with cellular proliferation through particular transporters functionally expressed by synovium in rheumatoid arthritis.
Asunto(s)
Artritis Experimental/metabolismo , Transportador 2 de Aminoácidos Excitadores/genética , Transportador 3 de Aminoácidos Excitadores/genética , Ácido Glutámico/metabolismo , Membrana Sinovial/metabolismo , Animales , Células Cultivadas , Citocinas/biosíntesis , Transportador 1 de Aminoácidos Excitadores/genética , Fibroblastos/metabolismo , Ácido Glutámico/farmacología , Masculino , ARN Mensajero/análisis , Ratas , Ratas Endogámicas Lew , Transducción de Señal , Membrana Sinovial/citologíaRESUMEN
Matrix metalloproteinase (MMP) has been implicated in joint destruction of chronic arthritis diseases, such as rheumatoid arthritis. FR217840 (2R)-1-([5-(4-fluorophenyl)-2-thienyl]sulfonyl)-N-hydroxy-4-(methylsulfonyl)-2-piperazinecarboxamide is a potent, orally active synthetic MMP inhibitor that inhibits human collagenases (MMP-1, MMP-8 and MMP-13), gelatinases (MMP-2 and MMP-9) and membrane type MMP (MT-MMP) (MT1-MMP/MMP-14). FR217840 also inhibits rat collagenase and gelatinase. We studied the effect of FR217840 on a rat adjuvant induced arthritis model. Although oral administration (days 1-21) of FR217840 (3.2, 10, 32 mg/kg) to adjuvant injected Lewis rats did not affect inflammation, as indicated by both hind paw swelling and histological inflammatory infiltration, FR217840 suppressed both bone destruction and serum pyridinoline content in a dose-dependent manner. Also, FR217840 (32 mg/kg) reduced tartrate-resistant acid phosphatase (TRAP) cell number in the ankle joints of rats with arthritis. These results indicate that FR217840 successfully suppressed joint destruction and suggest that FR217840 may have potential as a novel anti-rheumatic drug.
Asunto(s)
Artritis Experimental/prevención & control , Artropatías/prevención & control , Inhibidores de la Metaloproteinasa de la Matriz , Piperazinas/farmacología , Fosfatasa Ácida/metabolismo , Aminoácidos/sangre , Animales , Articulación del Tobillo/diagnóstico por imagen , Articulación del Tobillo/efectos de los fármacos , Articulación del Tobillo/patología , Artritis Experimental/diagnóstico por imagen , Artritis Experimental/patología , Línea Celular , Células Cultivadas , Colagenasas/metabolismo , Progresión de la Enfermedad , Femenino , Humanos , Isoenzimas/metabolismo , Artropatías/diagnóstico por imagen , Artropatías/patología , Metaloproteinasa 1 de la Matriz/metabolismo , Metaloproteinasa 13 de la Matriz , Metaloproteinasa 8 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/metabolismo , Metaloproteinasas de la Matriz/metabolismo , Piperazinas/uso terapéutico , Inhibidores de Proteasas/farmacología , Inhibidores de Proteasas/uso terapéutico , Radiografía , Ratas , Ratas Endogámicas Lew , Fosfatasa Ácida Tartratorresistente , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
FR255031 (2-[(7S)-7-[5-(4-ethylphenyl)-2-thienyl]-1,1-dioxido-4-(2-pyridinylcarbonyl)hexahydro-1,4-thiazepin-7-yl]-N-hydroxyacetamide) is a novel synthetic matrix metalloproteinase (MMP) inhibitor that inhibits human collagenases (MMP-1, MMP-8 and MMP-13), gelatinases (MMP-2 and MMP-9) and membrane type 1 MMP (MT1-MMP/MMP-14). FR255031 also inhibits rat collagenase and gelatinase. We studied the effect of FR255031 and Trocade, an inhibitor of collagenase and MMP-14, on a rat collagen-induced arthritis (CIA) model. Rat CIA was induced by intradermal injection of type II collagen (IIC) and oral administration of FR255031 or Trocade was performed for 28 days. Body weight loss, hind paw swelling, elevation of serum anti-IIC antibody, and histological and radiographic scores were evaluated. FR255031 markedly inhibited cartilage degradation in a dose-dependent manner in the CIA model, but Trocade failed to prevent the degradation. FR255031 at a dose of 100 mg kg(-1) also had statistically significant effects on bone destruction and pannus formation and on the recovery of body weight loss on day 28. These results indicate that FR255031 is effective for rat CIA, especially on joint cartilage destruction. These data suggest that as well as collagenases or MT-MMP, gelatinases are also involved in joint destruction in arthritis.