RESUMEN
Maresin 1 is a novel pro-resolving mediator derived from docosahexaenoic acid (DHA), with potent anti-inflammation effects against several animal models, including brain ischemia, sepsis, and lung fibrosis. However, its effect against motor neuron cell death is still not investigated. Therefore, we investigated the effects of maresin 1 on several stress-induced motor neuron cell death. Maresin 1 suppressed combinatorial stress which was evoked by superoxide dismutase 1 (SOD1)G93A and serum-free, -induced motor neuron cells death in a concentration-dependent manner, and had a stronger neuroprotective effective than DHA. Maresin 1 also had neuroprotective effects against transactivation response DNA-binding protein (TDP)-43A315T and serum-free stress, H2O2, and tunicamycin-induced cell death. Maresin 1 reduced the reactive oxygen species (ROS) production caused by SOD1G93A or TDP-43A315T. Moreover, maresin 1 suppressed the NF-κB activation induced by SOD1G93A and serum-free stress. These data indicate that maresin 1 has motor neuron protective effects against several stresses by reduction of ROS production or attenuation of the NF-κB activation. Maresin 1 also had neuroprotective effects against H2O2, and tunicamycin-induced cell death in a concentration-dependent manner. Finally, maresin 1 ameliorated the motor function deficits of spinal muscular atrophy model in which endoplasmic reticulum stress was upregulated. Thus, maresin 1 may be beneficial to protect against motor neuron diseases.
Asunto(s)
Ácidos Docosahexaenoicos/farmacología , Neuronas Motoras/efectos de los fármacos , Neuronas Motoras/metabolismo , Fármacos Neuroprotectores/farmacología , Animales , Muerte Celular/efectos de los fármacos , Muerte Celular/fisiología , Ácidos Docosahexaenoicos/química , Relación Dosis-Respuesta a Droga , Ratones , Ratones Transgénicos , FN-kappa B/antagonistas & inhibidores , FN-kappa B/metabolismo , Fármacos Neuroprotectores/química , Especies Reactivas de Oxígeno/antagonistas & inhibidores , Especies Reactivas de Oxígeno/metabolismo , Células Tumorales CultivadasRESUMEN
Earlier studies showed that the expressions of the agonists of the cannabinoid receptors are reduced in the vitreous humor of patients with age-related macular degeneration (AMD), and the cannabinoid type 2 receptor is present in the retinas of rats and monkeys. The purpose of this study was to determine whether the cannabinoid type 2 receptor is involved in the light-induced death of cultured 661W cells, an immortalized murine retinal cell line, and in the light-induced retinal degeneration in mice. Time-dependent changes in the expression and location of retinal cannabinoid type 2 receptor were determined by Western blot and immunostaining. The cannabinoid type 2 receptor was down-regulated in murine retinae and cone cells. In the in vitro studies, HU-308, a cannabinoid type 2 receptor agonist, had a protective effect on the light-induced death of 661W cells, and this effect was attenuated by SR144528, a cannabinoid type 2 receptor antagonist. Because the cannabinoid type 2 receptor is a G-protein coupled receptor and is coupled with Gi/o protein, we investigated the effects of the cAMP-dependent protein kinase (PKA). HU-308 and H89, a PKA inhibitor, deactivated PKA in retinal cone cells, and H89 also suppressed light-induced cell death. For the in vivo studies, a cannabinoid type 2 receptor agonist, HU-308, or an antagonist, SR144528, was injected intravitreally into mouse eyes before the light exposure. Electroretinography was used to determine the physiological status of the retinas. Injection of HU-308 improved the a- and b-waves of the ERGs and also the thickness of the outer nuclear layer of the murine retina after light exposure. These findings indicate that the cannabinoid type 2 receptor is involved in the light-induced retinal damage through PKA signaling. Thus, activation of cannabinoid type 2 receptor may be a therapeutic approach for light-associated retinal diseases.
Asunto(s)
Luz , Células Fotorreceptoras de Vertebrados/metabolismo , Traumatismos Experimentales por Radiación/metabolismo , Receptor Cannabinoide CB2/fisiología , Retina/efectos de la radiación , Degeneración Retiniana/metabolismo , Animales , Western Blotting , Canfanos/farmacología , Agonistas de Receptores de Cannabinoides/farmacología , Antagonistas de Receptores de Cannabinoides/farmacología , Cannabinoides/farmacología , Línea Celular , Supervivencia Celular/fisiología , Electrorretinografía , Humanos , Masculino , Ratones , Células Fotorreceptoras de Vertebrados/patología , Pirazoles/farmacología , Traumatismos Experimentales por Radiación/patología , Traumatismos Experimentales por Radiación/prevención & control , Receptor Cannabinoide CB2/agonistas , Receptor Cannabinoide CB2/antagonistas & inhibidores , Retina/patología , Degeneración Retiniana/patología , Degeneración Retiniana/prevención & control , Epitelio Pigmentado de la Retina/efectos de la radiaciónRESUMEN
The endocannabinoid system is involved in some neurodegenerative diseases such as Alzheimer's disease. An endogenous constellation of proteins related to cannabinoid1 receptor signaling, including free fatty acids, diacylglycerol lipase, and N-acylethanolamine-hydrolyzing acid amidase, are localized in the murine retina. Moreover, the expression levels of endogenous agonists of cannabinoid receptors are changed in the vitreous fluid. However, the role of the endocannabinoid system in the retina, particularly in the light-induced photoreceptor degeneration, remains unknown. Therefore, we investigated involvement of the cannabinoid1 receptor in light-induced retinal degeneration using in vitro and in vivo models. To evaluate the effect of cannabinoid1 receptors in light irradiation-induced cell death, the mouse retinal cone-cell line (661W) was treated with a cannabinoid1 receptor antagonist, rimonabant. Time-dependent changes of expression and localization of retinal cannabinoid1 receptors were measured using Western blot and immunostaining. Retinal damage was induced in mice by exposure to light, followed by intravitreal injection of rimonabant. Electroretinograms and histologic analyses were performed. Rimonabant suppressed light-induced photoreceptor cell death. Cannabinoid1 receptor expression was upregulated by light exposure. Treatment with rimonabant improved both a- and b-wave amplitudes and the thickness of the outer nuclear layer. These results suggest that the cannabinoid1 receptor is involved in light-induced retinal degeneration and it may represent a therapeutic target in the light-induced photoreceptor degeneration related diseases.