RESUMEN
OBJECTIVE: Mitogen-activated protein kinase (MAPK) p38 inhibitors have entered the clinical phase, although many of them have failed due to high toxicity and lack of efficacy. In the present study we compared the effects of the selective p38 inhibitor ML3403 and the dual p38-PDE4 inhibitor CBS-3595, on inflammatory and nociceptive parameters in a model of polyarthritis in rats. METHODS: Male Wistar rats (180-200 g) were used for the complete Freund's adjuvant (CFA)-induced arthritis model and they were evaluated at 14-21 days. We also analysed the effects of these pharmacological tools on liver and gastrointestinal toxicity and on cytokine levels. RESULTS: Repeated CBS-3595 (3 mg/kg) or ML3403 (10 mg/kg) administration produced significant anti-inflammatory actions in the chronic arthritis model induced by CFA. CBS-3595 and ML3403 treatment also markedly reduced the production of the proinflammatory cytokine IL-6 in the paw tissue, whereas it widely increased the levels of the anti-inflammatory cytokine IL-10. Moreover, CBS-3595 produced partial anti-allodynic effects in the CFA model at 4 and 8 days after treatment. Notably, ML3403 and CBS-3595 did not show marked signs of hepatoxicity, as supported by unaltered histological observations in the liver sections. Finally, both compounds were safe in the gastrointestinal tract, according to evaluation of intestinal biopsies. CONCLUSION: CBS-3595 displayed a superior profile regarding its anti-inflammatory effects. Thus p38 MAPK/PDE4 blocking might well constitute a relevant strategy for the treatment of RA.
Asunto(s)
Artritis Experimental/tratamiento farmacológico , Imidazoles/uso terapéutico , Inhibidores de Fosfodiesterasa 4/uso terapéutico , Inhibidores de Proteínas Quinasas/uso terapéutico , Piridinas/uso terapéutico , Proteínas Quinasas p38 Activadas por Mitógenos/antagonistas & inhibidores , Aminopiridinas/farmacología , Aminopiridinas/uso terapéutico , Animales , Artritis Experimental/inducido químicamente , Biopsia , Citocinas/metabolismo , Modelos Animales de Enfermedad , Adyuvante de Freund/efectos adversos , Tracto Gastrointestinal/efectos de los fármacos , Tracto Gastrointestinal/patología , Imidazoles/farmacología , Hígado/efectos de los fármacos , Hígado/patología , Masculino , Inhibidores de Fosfodiesterasa 4/farmacología , Inhibidores de Proteínas Quinasas/farmacología , Piridinas/farmacología , Ratas , Ratas Wistar , Resultado del TratamientoRESUMEN
Mitochondrial Ca(2+) Uniporter (MCU)-dependent mitochondrial Ca(2+) uptake is the primary mechanism for increasing matrix Ca(2+) in most cell types. However, a limited understanding of the MCU complex assembly impedes the comprehension of the precise mechanisms underlying MCU activity. Here, we report that mouse cardiomyocytes and endothelial cells lacking MCU regulator 1 (MCUR1) have severely impaired [Ca(2+)]m uptake and IMCU current. MCUR1 binds to MCU and EMRE and function as a scaffold factor. Our protein binding analyses identified the minimal, highly conserved regions of coiled-coil domain of both MCU and MCUR1 that are necessary for heterooligomeric complex formation. Loss of MCUR1 perturbed MCU heterooligomeric complex and functions as a scaffold factor for the assembly of MCU complex. Vascular endothelial deletion of MCU and MCUR1 impaired mitochondrial bioenergetics, cell proliferation, and migration but elicited autophagy. These studies establish the existence of a MCU complex that assembles at the mitochondrial integral membrane and regulates Ca(2+)-dependent mitochondrial metabolism.