Analysis of Caspase-9 protein and microRNAs miR-21, miR-126 and miR-155 related to the apoptosis mechanism in the cerebellum of rats submitted to focal cerebral ischemia associated with an alcoholism model / Análise da proteína Caspase-9 e dos microRNAs miR-21, miR-126 e miR-155 relacionados ao mecanismo de apoptose no cerebelo de ratos submetidos à isquemia cerebral focal associada ao modelo de alcoolismo

ABSTRACT This study aimed to analyze the cerebellum of rats submitted to an experimental focal cerebral ischemia, by middle cerebral artery occlusion for 90 minutes, followed by reperfusion for 48 hours, associated with an alcoholism model. Methods Fifty adult Wistar rats were used, subdivided into five experimental groups: control group (C): animals submitted to anesthesia only; sham group (S): animals submitted to complete simulation of the surgical procedure; ischemic group (I): animals submitted to focal cerebral ischemia for 90 minutes followed by reperfusion for 48 hours; alcoholic group (A): animals that received daily absolute ethanol diluted 20% in water for four weeks; and, ischemic and alcoholic group (I + A): animals receiving the same treatment as group A and, after four weeks, submitted to focal cerebral ischemia for 90 minutes, followed by reperfusion for 48 hours. The cerebellum samples were collected and immunohistochemical analysis of Caspase-9 protein and serum analysis by RT-PCR of microRNAs miR-21, miR-126 and miR155 were performed. Results The expression of Caspase-9 was higher in groups I, A and I + A. In the microRNAs analyses, miR-126 was higher in groups A and I + A, miR-155 was higher in groups I and I + A. Conclusions We conclude that apoptosis occurs in the cerebellar cortex, even if it is distant from the ischemic focus, and that microRNAs 126 and 155 show a correlation with cellular apoptosis in ischemic rats and those submitted to the chronic alcohol model.

RESUMO O objetivo deste estudo foi analisar o cerebelo de ratos submetidos à isquemia cerebral focal experimental, por oclusão da artéria cerebral média por 90 minutos, seguida de reperfusão por 48 horas, associada a um modelo de alcoolismo. Métodos Foram utilizados 50 ratos Wistar adultos, subdivididos em cinco grupos experimentais: grupo controle (C): animais submetidos apenas à anestesia; grupo sham (S): animais submetidos à simulação completa do procedimento cirúrgico; grupo isquêmico (I): animais submetidos à isquemia cerebral focal por 90 minutos, seguidos de reperfusão por 48 horas; grupo alcoólico (A): animais que receberam etanol absoluto diário diluído em 20% em água por quatro semanas; e grupo isquêmico e alcoólico (I + A): animais que recebem o mesmo tratamento do grupo A e, após quatro semanas, submetidos à isquemia cerebral focal por 90 minutos, seguidos de reperfusão por 48 horas. As amostras de cerebelo foram coletadas e a análise imuno-histoquímica da proteína Caspase-9 e a análise sérica por RT-PCR dos microRNAs miR-21, miR-126 e miR155 foram realizadas. Resultados A expressão de Caspase-9 foi maior nos grupos I, A e I + A. Nas análises de microRNAs, o miR-126 foi maior nos grupos A e I + A, o miR-155 foi maior nos grupos I e I + A. Conclusões Concluímos que a apoptose ocorre no córtex cerebelar, mesmo distante do foco isquêmico, e que os microRNAs 126 e 155 mostram uma correlação com a apoptose celular em ratos isquêmicos e submetidos ao modelo crônico de álcool.

Incremento del glutamato en el estriado de asociación en esquizofrenia. Resultados preliminares de un estudio longitudinal con espectroscopia con resonancia magnética / Glutamate increase in the associative striatum in schizophrenia: a longitudinal magnetic resonance spectroscopy preliminary study

Objetivo: Comparar los niveles de glutamato en el núcleo caudado dorsal, región rica en dopamina, y el cerebelo, región pobre en dopamina, en pacientes con esquizofrenia, durante un episodio psicótico agudo, después de recibir tratamiento antidopaminérgico (risperidona) y en controles sanos. Métodos: Se incluyeron 14 pacientes con esquizofrenia aguda sin tratamiento y 14 controles sanos. A los pacientes se les realizaron dos estudios de espectroscopia por resonancia magnética de protones (ERM1H). El primero antes de tratamiento y el segundo a las seis semanas de tratamiento efectivo. Los controles fueron evaluados en una ocasión. Los niveles de glutamato fueron normalizados con la concentración de creatina. Resultados: Los niveles de glutamato/creatina fueron mayores en el caudado dorsal de los pacientes previo a tratamiento (t=-2.16, p=0.03) y después del tratamiento en comparación con los controles (t=2.12, p=0.04). Los niveles de glutamato en el cerebelo no cambiaron con el tratamiento y fueron iguales a los controles. Conclusiones: Nuestros resultados indican que el incremento delglutamato en el caudado dorsal se encuentra en relación con la enfermedad y no cambia después de seis semanas de tratamiento antipsicótico efectivo. Más aún, la ausencia de diferencias en el cerebelo sugiere que el incremento del glutamato presente en la esquizofrenia se podría relacionar a regiones con abundante inervación dopaminérgica.

OBJECTIVE: To compare glutamate levels (Glu) found in the dorsal-caudate nucleus (a dopamine rich region) and in the cerebellum (a low dopamine region) among: 1) schizophrenia patients undergoing an acute psychotic episode, 2) after receiving antidopaminergic treatment (Risperidone), and 3) healthy controls. METHODS: Fourteen drug-free patients with schizophrenia and fourteen healthy controls were included. Patients underwent two proton magnetic resonance spectroscopy (1H-MRS) studies, one prior to treatment and the second after 6-weeks of daily Risperidone treatment. Controls underwent one 1H-MRS study. Glutamate levels were normalized according to the relative concentration of Creatine (Cr). RESULTS: The dorsal-caudate nucleus among schizophrenia patients showed higher levels of Glu/Cr during the drug-free condition (t = -2.16, p = 0.03) and after antipsychotic treatment (t = 2.12, p = 0.04) compared with controls. No difference was observed in the cerebellum between the drug-free, post-treatment and controls conditions. CONCLUSIONS: Our results suggest that the Glu increase observed in the dorsal-caudate in schizophrenia is illness-mediated and does not change after 6-weeks of antipsychotic treatment. Moreover, the lack of change detected in the cerebellum suggests that the Glu increase in schizophrenia is not ubiquitous within the brain and that may be associated with dopamine target regions.

Sporadic creutzfeldt-Jakob disease. A clinical-neuropathological analysis of nine definite cases

The authors have analyzed clinico-neuropathologically nine cases of the definite sporadic form of Creutzfeldt-Jakob disease (CJD). All cases were female, with mean age of 62.7 years. Eighty-nine percent of the patients exhibited prodromal and initial psychiatric symptoms; definite signs of dementia, and myoclonus were present in 100 per cent of cases. The EEG was abnormal in all cases and pseudoperiodic paroxysms were present in 56 per cent of the patients. Their evolution time ranged from 3 to 19 months. Neuropathologically, brain and cerebellar atrophy, spongiosis, astrocytosis and neuronal loss were present in 100 per cent of the patients. In 5 (56 per cent) of these 9 cases, prion protein (PrP) amyloid plaques were detected in the cerebellum, by optical- and electronmicroscopy. There was a positive correlation between the number of plaques and the evolution time. The authors outline the similarities of their cases in the elderly with the new variant of CJD described in young people.