RESUMEN
We aimed to examine whether thalidomide might inhibit the neuronal damage resulting from focal cerebral ischemia, and if so to explore the neuroprotective mechanism. Focal cerebral ischemia was induced by permanent middle cerebral artery occlusion (MCAO) in mice, and thalidomide was intraperitoneally administered a total of three times (at 10 min before, just before, and 1 h after MCAO). Thalidomide significantly reduced (a) the infarct area and volume at 24 and 72 h after MCAO and (b) the neurological score at 72 h after MCAO. Brains were also histochemically assessed for apoptosis and lipid peroxidation using terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) staining and an antibody recognizing 8-hydroxy-2'-deoxyguanosine (8-OHdG), respectively. Thalidomide reduced both the number of TUNEL-positive cells and the oxidative damage. However, post-treatment of thalidomide [20 mg/kg, three times (at just after, 1 h after, 3 h after MCAO)] did not reduce the infarct volume. In an in vitro study, we examined the effects of thalidomide on lipid peroxidation in mouse brain homogenates and on the production of various radical species. Thalidomide inhibited both the lipid peroxidation and the production of H(2)O(2) and O(2).(-) (but not HO(-)) radicals. We also measured the brain concentration of TNF-alpha by ELISA. The TNF-alpha level in the brain was significantly increased at 9-24 h after MCAO. However, thalidomide did not reduce the elevated TNF-alpha level at either 12 or 24 h after MCAO. These findings indicate that thalidomide has neuroprotective effects against ischemic neuronal damage in mice, and that an inhibitory action of thalidomide against oxidative stress may be partly responsible for these neuroprotective effects.
Asunto(s)
Infarto Cerebral/etiología , Infarto Cerebral/prevención & control , Infarto de la Arteria Cerebral Media/complicaciones , Fármacos Neuroprotectores/uso terapéutico , Talidomida/uso terapéutico , 8-Hidroxi-2'-Desoxicoguanosina , Análisis de Varianza , Animales , Presión Sanguínea/efectos de los fármacos , Muerte Celular/efectos de los fármacos , Células Cultivadas , Infarto Cerebral/metabolismo , Desoxiguanosina/análogos & derivados , Desoxiguanosina/metabolismo , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Depuradores de Radicales Libres/metabolismo , Frecuencia Cardíaca/efectos de la radiación , Etiquetado Corte-Fin in Situ/métodos , Técnicas In Vitro , Peroxidación de Lípido/efectos de los fármacos , Masculino , Ratones , Enfermedades del Sistema Nervioso/etiología , Enfermedades del Sistema Nervioso/prevención & control , Células Ganglionares de la Retina/efectos de los fármacos , Factores de Tiempo , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
SUN N8075 is a novel antioxidant with neuroprotective properties. This study was designed to elucidate its neuroprotective effects against 6-hydroxy dopamine (6-OHDA)-induced cell death and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neurotoxicity (known as in vitro and in vivo models of Parkinson's disease, respectively). In the in vitro study, on human neuroblastoma SH-SY5Y cells, SUN N8075 decreased the hydrogen peroxide (H2O2)-induced production of reactive oxygen species and protected against 6-OHDA-induced cell death. In the in vivo study, SUN N8075, when injected intraperitoneally (i.p.) twice with a 5-h interval, inhibited lipid peroxidation (viz. the production of thiobarbituric acid reactive substance) in the mouse forebrain at 1 h after the second injection. Mice were injected i.p. with MPTP (10 mg/kg) four times at 1-h intervals, and brains were analyzed 7 days later. SUN N8075 at 30 mg/kg (i.p., twice) exhibited a protective effect against the MPTP-induced decrease in tyrosine hydroxylase (TH)-positive fibers in the striatum. Moreover, SUN N8075 at 10 and 30 mg/kg (i.p., twice) had a similar protective effect against the MPTP-induced decrease in TH-positive cells in the substantia nigra. Further, SUN N8075 30 mg/kg (i.p. twice) markedly suppressed the MPTP-induced accumulation of 8-hydroxy-deoxyguanosine (8-OHdG) in the striatum. These findings indicate that SUN N8075 exerts protective effects, at least in part via an anti-oxidation mechanism, in these in vitro and in vivo models of Parkinson's disease.
Asunto(s)
Compuestos de Anilina/uso terapéutico , Antioxidantes/uso terapéutico , Trastornos Parkinsonianos/prevención & control , Piperazinas/uso terapéutico , 1-Metil-4-fenil-1,2,3,6-Tetrahidropiridina , Adrenérgicos/toxicidad , Análisis de Varianza , Animales , Peso Corporal/efectos de los fármacos , Peso Corporal/fisiología , Muerte Celular/efectos de los fármacos , Línea Celular Tumoral , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Interacciones Farmacológicas , Humanos , Peróxido de Hidrógeno/farmacología , Peroxidación de Lípido/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL , Neuroblastoma/patología , Oxidopamina/toxicidad , Trastornos Parkinsonianos/inducido químicamente , Especies Reactivas de Oxígeno/metabolismoRESUMEN
Endoplasmic reticulum (ER) stress, which is caused by the accumulation of unfolded proteins in the ER lumen, is associated with stroke and neurodegenerative diseases such as Parkinson's and Alzheimer's diseases. We evaluated the effect of a selective inducer of immunoglobulin heavy chain binding protein (BiP) (BiP inducer X; BIX) against both tunicamycin-induced cell death (in SH-SY5Y cells) and the effects of global transient forebrain ischemia (in gerbils). BIX significantly induced BiP expression both in vitro and in vivo. Pretreatment with BIX at 2 or 5 microM reduced the cell death induced by tunicamycin in SH-SY5Y cells. In gerbils subjected to forebrain ischemia, prior treatment with BIX (intracerebroventricular injection at 10 or 40 microg) protected against cell death and decreased TUNEL-positive cells in the hippocampal CA1 subfield. These findings indicate that this selective inducer of BiP could be used to prevent the neuronal damage both in vitro and in vivo.