Protective effects of various doses of Glycyrrhizin on hippocampal tissue of young rats with status epilepticus / 中华实用儿科临床杂志

Objective:To study the protective effects of various doses of Glycyrrhizin on hippocampus of young rats with status epilepticus (SE).Methods:Lithium chloride and pilocarpine were injected intraperitoneally into male Sprague-Dawley (SD) rats (with a postnatal age of 18-21 days), so as to induce SE in rats.The rats were divided into 5 groups according to the random number table method: control group, SE group, SE+ low dose Glycyrrhizin group, SE+ medium dose Glycyrrhizin group and SE+ high dose Glycyrrhizin group.Three different doses of Glycyrrhizin (20 mg/kg, 40 mg/kg and 60 mg/kg) were injected intraperitoneally into the rats.The levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6 in serum of SE rats were determined by enzyme linked immunosorbent assay.Quantitative real-time PCR (qRT-PCR) was used to detect the mRNA expression levels of TNF- α, IL-1β and IL-6 in hippocampus of SE rats.The expression levels of Bax, Bcl-2 and Caspase-3 in hippocampus were detected by Western blot.The damage of neurons was measured by hematoxylin and eosin (HE) staining and Nissl staining.Neurons apoptosis was examined by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL). The mitochondrial changes were observed under transmission electron microscopy.One-way ANOVA followed by Tukey post-hoc test was used for statistical analysis. Results:Compared to the control group, TNF-α[(369.69±58.07) ng/L vs. (75.46±14.64) ng/L], IL-1β[(242.27±25.23) ng/L vs. (45.29±5.90) ng/L] and IL-6[(288.15±24.60) ng/L vs. (46.59±8.80) ng/L] in the serum of SE rats were significantly up-regulated(all P<0.05). Compared to SE group, low, medium and high doses Glycyrrhizin could effectively reduce the levels of TNF-α[(216.67±8.31) ng/L, (158.81±5.03) ng/L and (113.69±12.54) ng/L vs. (369.69±58.07) ng/L], IL-1β[(131.21±5.50) ng/L, (86.60±7.79) ng/L and (65.06±4.39) ng/L vs. (242.27±25.23) ng/L] and IL-6[(150.24±9.48) ng/L, (101.70±5.85) ng/L and (91.60±2.81) ng/L vs. (288.15±24.60) ng/L] released in serum after SE occurred (all P<0.05). The neuronal damage, loss, apoptosis and mitochondrial damage were found in the hippocampus of SE rats.Glycyrrhizin could ameliorate these symptoms.Compared to the control group, Bax levels(0.57±0.01 vs. 0.14±0.01)and Caspase-3 levels(0.54±0.00 vs. 0.11±0.01)in the hippocampus of SE rats were markedly increased, while Bcl-2 levels(0.27±0.01 vs. 0.57±0.02)were decreased(all P<0.05). Compared to the SE group, low, medium and high doses Glycyrrhizin could effectively reduce the levels of Bax(0.51±0.02, 0.45±0.03 and 0.40±0.02 vs. 0.57±0.01)and Caspase-3(0.47±0.02, 0.42±0.02 and 0.37±0.01 vs. 0.54±0.00), and increase the levels of Bcl-2(0.41±0.02, 0.45±0.02 and 0.51±0.01 vs. 0.27±0.01)(all P<0.05). Conclusions:Glycyrrhizin can effectively protect the hippocampus of young rats with SE.

Protective effects of various doses of Glycyrrhizin on hippocampal tissue of young rats with status epilepticus / 中华实用儿科临床杂志

Objective:To study the protective effects of various doses of Glycyrrhizin on hippocampus of young rats with status epilepticus (SE).Methods:Lithium chloride and pilocarpine were injected intraperitoneally into male Sprague-Dawley (SD) rats (with a postnatal age of 18-21 days), so as to induce SE in rats.The rats were divided into 5 groups according to the random number table method: control group, SE group, SE+ low dose Glycyrrhizin group, SE+ medium dose Glycyrrhizin group and SE+ high dose Glycyrrhizin group.Three different doses of Glycyrrhizin (20 mg/kg, 40 mg/kg and 60 mg/kg) were injected intraperitoneally into the rats.The levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6 in serum of SE rats were determined by enzyme linked immunosorbent assay.Quantitative real-time PCR (qRT-PCR) was used to detect the mRNA expression levels of TNF- α, IL-1β and IL-6 in hippocampus of SE rats.The expression levels of Bax, Bcl-2 and Caspase-3 in hippocampus were detected by Western blot.The damage of neurons was measured by hematoxylin and eosin (HE) staining and Nissl staining.Neurons apoptosis was examined by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL). The mitochondrial changes were observed under transmission electron microscopy.One-way ANOVA followed by Tukey post-hoc test was used for statistical analysis. Results:Compared to the control group, TNF-α[(369.69±58.07) ng/L vs. (75.46±14.64) ng/L], IL-1β[(242.27±25.23) ng/L vs. (45.29±5.90) ng/L] and IL-6[(288.15±24.60) ng/L vs. (46.59±8.80) ng/L] in the serum of SE rats were significantly up-regulated(all P<0.05). Compared to SE group, low, medium and high doses Glycyrrhizin could effectively reduce the levels of TNF-α[(216.67±8.31) ng/L, (158.81±5.03) ng/L and (113.69±12.54) ng/L vs. (369.69±58.07) ng/L], IL-1β[(131.21±5.50) ng/L, (86.60±7.79) ng/L and (65.06±4.39) ng/L vs. (242.27±25.23) ng/L] and IL-6[(150.24±9.48) ng/L, (101.70±5.85) ng/L and (91.60±2.81) ng/L vs. (288.15±24.60) ng/L] released in serum after SE occurred (all P<0.05). The neuronal damage, loss, apoptosis and mitochondrial damage were found in the hippocampus of SE rats.Glycyrrhizin could ameliorate these symptoms.Compared to the control group, Bax levels(0.57±0.01 vs. 0.14±0.01)and Caspase-3 levels(0.54±0.00 vs. 0.11±0.01)in the hippocampus of SE rats were markedly increased, while Bcl-2 levels(0.27±0.01 vs. 0.57±0.02)were decreased(all P<0.05). Compared to the SE group, low, medium and high doses Glycyrrhizin could effectively reduce the levels of Bax(0.51±0.02, 0.45±0.03 and 0.40±0.02 vs. 0.57±0.01)and Caspase-3(0.47±0.02, 0.42±0.02 and 0.37±0.01 vs. 0.54±0.00), and increase the levels of Bcl-2(0.41±0.02, 0.45±0.02 and 0.51±0.01 vs. 0.27±0.01)(all P<0.05). Conclusions:Glycyrrhizin can effectively protect the hippocampus of young rats with SE.

Neuron-specific enolase as biomarker for possible neuronal damage in dogs with distemper vírus / Enolase neuronal específica como um possível biomarcador para lesão neuronal em cães com cinomose

Neuron-specific enolase (NSE) is a biomarker of neuronal cell lysis, which demonstrates stability in extracellular fluids such as blood and cerebrospinal fluid. To the authors knowledge there is no research information comparing the use of NSE in dogs with and without encephalitis, putting in evidence the importance of that biomarker to detect neuronal damage in dogs. The objective was to compare the serum NSE levels in dogs with and without encephalitis, and to determine the serum NSE levels in normal dogs. Thirty eight dogs were evaluated, 19 dogs with encephalitis (EG Group) and 19 dogs without encephalitis (CG Group). The criteria for inclusion in the EG Group were presence of neurological signs in more than one part of the CNS (multifocal syndrome) and positive molecular diagnosis for canine distemper virus; for the CG Group were an age between 1 to 7 years and be clinically normal; NSE were measured in serum using an ELISA assay, and the results were compared. In the EG Group the NSE values were higher with significant difference (P=0.0053) when compared with the CG Group. NSE is a biomarker that can be measured in serum samples of dogs to monitor neuronal lesions in encephalitis.(AU)

Enolase neuronal específica (NSE) é um biomarcador de lise de neurônios, que demonstra estabilidade em fluidos extracelulares como sangue e líquido cerebrospinal. Para o conhecimento dos autores, não há informações de pesquisa que comparem o uso de NSE em cães com e sem encefalite, evidenciando a importância desse biomarcador para detectar danos neuronais em cães. O objetivo foi comparar os níveis séricos de NSE em cães com e sem encefalites, e determinar os níveis séricos de NSE em cães saudáveis. Trinta e oito cães foram avaliados, 19 cães com encefalites (Grupo EG) e 19 cães sem encefalite (Grupo CG). O critério para inclusão no Grupo EG foi presença de sinais neurológicos em mais de uma estrutura do SNC (síndrome multifocal) e positividade no diagnóstico molecular para o vírus da cinomose canina; para o Grupo CG foi idade entre 1 e 7 anos e ser clinicamente normal; NSE foram mensuradas em amostras séricas usando o método de ELISA, e os resultados comparados. No Grupo EG os valores de NSE foram altos com diferença significativa (P=0.0053) quando comparado com o Grupo CG. NSE é um biomarcador que pode ser mensurado em amostras séricas de cães para monitorar lesões neuronais em encefalites.(AU)

MicroRNA-365 Knockdown Prevents Ischemic Neuronal Injury by Activating Oxidation Resistance 1-Mediated Antioxidant Signals / 神经科学通报·英文版

MicroRNA-365 (miR-365) is upregulated in the ischemic brain and is involved in oxidative damage in the diabetic rat. However, it is unclear whether miR-365 regulates oxidative stress (OS)-mediated neuronal damage after ischemia. Here, we used a transient middle cerebral artery occlusion model in rats and the hydrogen peroxide-induced OS model in primary cultured neurons to assess the roles of miR-365 in neuronal damage. We found that miR-365 exacerbated ischemic brain injury and OS-induced neuronal damage and was associated with a reduced expression of OXR1 (Oxidation Resistance 1). In contrast, miR-365 antagomir alleviated both the brain injury and OXR1 reduction. Luciferase assays indicated that miR-365 inhibited OXR1 expression by directly targeting the 3'-untranslated region of Oxr1. Furthermore, knockdown of OXR1 abolished the neuroprotective and antioxidant effects of the miR-365 antagomir. Our results suggest that miR-365 upregulation increases oxidative injury by inhibiting OXR1 expression, while its downregulation protects neurons from oxidative death by enhancing OXR1-mediated antioxidant signals.

Beta-glucan attenuates cerebral ischemia/reperfusion-induced neuronal injury in a C57BL/J6 mouse model

Beta-glucans (ßg), that have many useful effects on human health, are natural polysaccharides. Our aim in this study was to determine useful effect of ßg against oxidative and neuronal damage caused by global cerebral ischemia/reperfusion (IR) in stroke imitated mice via surgical operation. A total of 40 mice divided into four equal groups randomly. The group 1 (sham operated) was kept as control. Bilateral carotid arteries of subjects in group 2 (I/R) and group 4 (I/ R + ßg) were clipped for 15 min, and the mice in group 4 (I/R + ßg) were treated with ßg (50 mg/kg/day), while the mice in group 2 (I/R) were treated with only vehicle for 10 days. The mice of group 3 (ßg) were treated with ßg for 10 days without carotid occlusion. Global cerebral I/R significantly increased oxidative stress and decreased members of anti-oxidant defense system. In addition, I/R caused histopathological damage in the brain tissue. However, ßg treatment ameliorated both oxidative and histopathological effects of I/R. Our present study showed that ßg treatment significantly ameliorated oxidative and histological damage in the brain tissue caused by cerebral I/R. Therefore, ßg treatment can be used as supportive care for ischemic stroke patients

Long Noncoding RNA NEAT1 Aggravates Aβ-Induced Neuronal Damage by Targeting miR-107 in Alzheimer's Disease

PURPOSE: Alzheimer's disease (AD) is the most common neurodegenerative disease, with a rising prevalence worldwide. Long noncoding RNAs (lncRNAs) have been found to play important roles in the development and treatment of AD. However, the exact role of lncRNA nuclear enriched abundant transcript 1 (NEAT1) in neuronal damage in AD is largely unknown. MATERIALS AND METHODS: The AD model was established in SH-SY5Y and SK-N-SH cells via treatment with amyloid β1−42 (Aβ). The expression of NEAT1 and microRNA-107 (miR-107) was measured by quantitative real-time polymerase chain reaction. Cell viability and apoptosis were detected by MTT assay, immunocytochemistry, and flow cytometry. The expression of phosphorylated tau protein (p-Tau) was measured by Western blot. The interaction between NEAT1 and miR-107 was explored by bioinformatics analysis, luciferase activity, and RNA immunoprecipitation assays. RESULTS: NEAT1 expression was enhanced in Aβ-treated SH-SY5Y and SK-N-SH cells, and its knockdown attenuated Aβ-induced inhibition of viability and promotion of apoptosis and p-Tau levels. NEAT1 was indicated as a decoy of miR-107. miR-107 abundance was reduced in Aβ-treated cells, and its overexpression reversed Aβ-induced injury. Moreover, interference of miR-107 abated silencing of NEAT1-mediated inhibition of neuronal damage in Aβ-treated SH-SY5Y and SK-N-SH cells. CONCLUSION: LncRNA NEAT1 aggravated Aβ-induced neuronal damage by sponging miR-107, indicating a novel avenue for treatment of AD.

Function of N-Methyl-D-Aspartic Acid Receptors in Cerebral Stroke / 中国药学杂志

Cerebral stroke is caused by the interrupt of blood supply either by the blockage or by the rupture of the brain blood vessels. After the activation of the ischemic cascades, a series of neurochemical reactions might occur which involves the excess release of the excitatory amino acids. The ionotropic glutamate receptor of N-methyl-D-aspartic acid subtype (NMDA receptor) has been proven to play dual roles in the ischemic insults. On one hand, NMDA receptor has been proven to initiate the ischemic impairment, leading to the neuronal death. On the other hand, NMDA receptor is involved in the endo-neurogenesis process after the ischemic onset. Herein, we summarized the recent studies about the structures and functions of NMDA receptor in ischemic stroke pathogenesis.

Effects of Acupuncture on Oxidative Stress and Neuronal Damage in Prefrontal Cortex of Vascular Dementia Rats / 中国中医药信息杂志

Objective To observe the effects of acupuncture on oxidative stress and neuronal damage in the prefrontal cortex of chronic cerebral hypoperfusion (CCH) rats; To investigate the molecular mechanisms of acupuncture in cognitive impairment of vascular dementia (VD) rats. Methods The animal model of VD was replicated by permanent bilateral common carotid artery occlusion (2VO) to induce CCH in rats. After modeling, rats were randomized into model group, acupuncture group and non-acupoint group. Sham-operation group was set as control group. Rats of acupuncture group and non-acupoint group were treated with needling for 2 weeks at 3 days after 2VO. Nissl and DHE staining were respectively used to evaluate the numbers of neurons and ROS level. SOD activity was examined by xanthine oxidase technique. Results Compared with sham-operation group, the number of neurons and SOD activity decreased in the model group, while the ROS level increased. Compared with the model group, the number of neurons and SOD activity increased in the acupuncture group, while the ROS level decreased. There were no obvious changes in all indexes in non-acupoint group. Conclusion Acupuncture can inhibit oxidative stress and improve neuronal damage and loss in the prefrontal cortex of VD rats.

Antiapoptotic and neuroprotective role of Curcumin in Pentylenetetrazole (PTZ) induced kindling model in rat.

Kindling, a sub threshold chemical or electrical stimulation, increases seizure duration and enhances accompanied behavior until it reaches a sort of equilibrium state. The present study aimed to explore the effect of curcumin on the development of kindling in PTZ kindled rats and its role in apoptosis and neuronal damage. In a PTZ kindled Wistar rat model, different doses of curcumin (100, 200 and 300 mg/kg) were administrated orally one hour before the PTZ injections on alternate day during the whole kindling days. The following parameters were compared between control and experimental groups: the course of kindling, stages of seizures, Histopathological scoring of hippocampus, antioxidant parameters in the hippocampus, DNA fragmentation and caspase-3 expression in hippocampus, and neuron-specific enolase in the blood. One way ANOVA followed by Bonferroni post hoc analysis and Fischer’s Exact test were used for statistical analyses. PTZ, 30 mg/kg, induced kindling in rats after 32.0±1.4 days. Curcumin showed dose-dependent anti-seizure effect. Curcumin (300 mg/kg) significantly increased the latency to myoclonic jerks, clonic seizures as well as generalized tonic-clonic seizures, improved the seizure score and decreased the number of myoclonic jerks. PTZ kindling induced a significant neuronal injury, oxidative stress and apoptosis which were reversed by pretreatment with curcumin in a dose-dependent manner. Our study suggests that curcumin has a potential antiepileptogenic effect on kindling-induced epileptogenesis.

Autophagy induction by SIRT6 is involved in oxidative stress-induced neuronal damage

SIRT6 is a NAD(+)-dependent histone deacetylase and has been implicated in the regulation of genomic stability, DNA repair, metabolic homeostasis and several diseases. The effect of SIRT6 in cerebral ischemia and oxygen/glucose deprivation (OGD) has been reported, however the role of SIRT6 in oxidative stress damage remains unclear. Here we used SH-SY5Y neuronal cells and found that overexpression of SIRT6 led to decreased cell viability and increased necrotic cell death and reactive oxygen species (ROS) production under oxidative stress. Mechanistic study revealed that SIRT6 induced autophagy via attenuation of AKT signaling and treatment with autophagy inhibitor 3-MA or knockdown of autophagy-related protein Atg5 rescued H2O2-induced neuronal injury. Conversely, SIRT6 inhibition suppressed autophagy and reduced oxidative stress-induced neuronal damage. These results suggest that SIRT6 might be a potential therapeutic target for neuroprotection.

El pirofosfato de tiamina reduce el daño celular inducido por hipoxia en el cerebro de ratas neonatas / Thiamine pyrophosphate reduces hypoxia-induced cellular damage in neonatal rat brain

La encefalopatía por hipoxia es causa de discapacidad y requiere de nuevas estrategias terapéuticas. El pirofosfato de tiamina (PPT) es un cofactor esencial de enzimas fundamentales en el metabolismo de la glucosa, cuya disminución puede conducir a la falla en la síntesis de ATP y a la muerte celular. El objetivo de este estudio fue determinar si la administración de PPT, puede reducir el daño celular en un modelo de hipoxia neonatal en ratas. Animales de 11 días de edad fueron tratados con PPT (130 mg/kg) en dosis única o solución salina, una hora antes del protocolo de hipoxia o al término de ésta. Los cerebros fueron colectados para la evaluación del daño celular. Además, se tomaron muestras sanguíneas para evaluar los indicadores gasométricos de presión de dióxido de carbono (PaCO2) y de oxígeno (PaO2) en sangre arterial y pH. Los resultados muestran que la administración de PPT previa a la inducción de hipoxia, reduce el daño celular y restablece los indicadores gasométricos. Estos datos indican que el uso de PPT reduce el daño inducido por la hipoxia en animales neonatos.

Hypoxic encephalopathy is a leading cause of disability and requires new therapeutic strategies. Thiamine pyrophosphate (TPP) is an essential cofactor of fundamental enzymes involved in glucose metabolism. TPP reduction may lead to ATP synthesis failure and cell death. The objective of this study was to determine if TPP administration can reduce cellular damage in a model of neonatal hypoxia in rats. Eleven day old animals were treated with TPP (130 mg/kg) as a single dose or with saline solution one hour before the hypoxia protocol or after ending the protocol. The brains were collected to evaluate cellular damage. Blood samples were also collected to evaluate arterial oxygen tension (PaO2), carbon dioxide tension (PaCO2) and acidity (pH). The results showed that TPP administration previous to hypoxia induction reduces cellular damage and reestablishes arterial blood gases. These data indicate that TPP use reduces the damage induced by hypoxia in neonatal animals.

The neuron-specific enolase levels of the cerebrospinal fluid in children with convulsion / 临床儿科杂志

Objective To explore the levels of neuron-speciifc enolase (NSE) of the cerebrospinal lfuid (CSF) in children with convulsion. Methods Ninety children with convulsion were enrolled. According to the frequency of convulsion attack, the children were divided into brief convulsion group 51 cases and prolonged convulsion group 39 cases, further, based on the etiology, the children were divided into viral encephalitis (VE) group, idiopathic epilepsy (EP) group, and febrile convulsion (FS) group. CSF was collected within 24-48 h convulsion attack. Twenty-three children with elective surgery were selected as a control group. CSF was collected before surgery. The NSE level of CSF were measured by ELISA method and compared among groups. Results The NSE levels of CSF in prolonged convulsion group and brief convulsion group were signiifcantly higher than that in control group, while the NES levels of CSF in prolonged convulsion group were signiifcantly higher than that in brief convulsion group (all P0.05). Conclusions Convulsion contributed to higher NSE levers of CSF, especially in children with prolonged convulsion attack or with VE. The NSE level of CSF can be regarded as an early objective indicator of brain damage after convulsions.

Effect of normabaric hyperoxia treatment on neuronal damage following fluid percussion injury in the striatum of mice: A morphological approach.

Traumatic brain injury (TBI) causes significant mortality in most developing countries worldwide. At present, it is imperative to identify a treatment to address the devastating post-TBI consequences. Therefore, the present study has been performed to assess the specific effect of immediate exposure to normabaric hyperoxia (NBO) after fluid percussion injury (FPI) in the striatum of mice. To execute FPI, mice were anesthetised and sorted into (i) a TBI group, (ii) a sham group without injury and (iii) a TBI group treated with immediate exposure to NBO for 3 h. Afterwards, brains were harvested for morphological assessment. The results revealed no changes in morphological and neuronal damage in the sham group as compared to the TBI group. Conversely, the TBI group showed severe morphological changes as well as neuronal damage as compared to the TBI group exposed to NBO for 3 h. Interestingly, our findings also suggested that NBO treatment could diminish the neuronal damage in the striatum of mice after FPI. Neuronal damage was evaluated at different points of injury and the neighbouring areas using morphology, neuronal apoptotic cell death and pan-neuronal markers to determine the complete neuronal structure. In conclusion, immediate exposure to NBO following FPI could be a potential therapeutic approach to reduce neuronal damage in the TBI model.

Association between Cerebrospinal Fluid S100B Protein and Neuronal Damage in Patients with Central Nervous System Infections

PURPOSE: S100B protein is widely used as a measure of glial activity or damage in several brain conditions. Central nervous system (CNS) infections can cause neurological sequelae because of parenchyma invasion. It is difficult to predict further neuronal damage in the CNS infection. The present study is aimed to evaluate the role of the cerebrospinal fluid (CSF) S100B protein as an indicator of neuronal damage in CNS infection. MATERIALS AND METHODS: We measured the concentration of CSF S100B protein in 62 patients with a CNS infection using an Enzyme-Linked Immunosorbent Assay. The patients with CNS infections were classified as having no neuronal damage (CNS-N) or as having neuronal damage (CNS+N) according to the presence of neurological change or structural lesions on brain MRI. RESULTS: The CSF S100B protein level of the CNS+N group (n=22, 0.235 microg/L, 0.10-2.18) was significantly higher than that of the CNS-N group (n=40, 0.087 microg/L, 0.06-0.12) and control group (n=40, 0.109 microg/L, 0.07-0.14, p<0.01). Using an arbitrary cut off value, S100B-positive CSF was detected in 2.5% of the CNS-N group and in 50% of the CNS+N group (p<0.05). CONCLUSION: These findings suggest that increased S100B protein levels in the CSF may be associated with the neuronal damage following CNS infections.

Systemic administration of low dosage of tetanus toxin decreases cell proliferation and neuroblast differentiation in the mouse hippocampal dentate gyrus / 한국실험동물학회지

In the present study, we investigated the effect of Tetaus toxin (TeT) on cell proliferation and neuroblast differentiation using specific markers: 5-bromo-2-deoxyuridine (BrdU) as an exogenous marker for cell proliferation, Ki-67 as an endogenous marker for cell proliferation and doublecortin (DCX) as a marker for neuroblasts in the mouse hippocampal dentate gyrus (DG) after TeT treatment. Mice were intraperitoneally administered 2.5 and 10 ng/kg TeT and sacrificed 15 days after the treatment. In both the TeT-treated groups, no neuronal death occurred in any layers of the DG using neuronal nuclei (NeuN, a neuron nuclei maker) and Fluoro-Jade B (F-J B, a high-affinity fluorescent marker for the localization of neuronal degeneration). In addition, no significant change in glial activation in both the 2.5 and 10 ng/kg TeT-treated-groups was found by GFAP (a marker for astrocytes) and Iba-1 (a marker for microglia) immunohistochemistry. However, in the 2.5 ng/kg TeT-treated-group, the mean number of BrdU, Ki-67 and DCX immunoreactive cells, respectively, were apparently decreased compared to the control group, and the mean number of each in the 10 ng/kg TeT-treated-group was much more decreased. In addition, processes of DCX-immunoreactive cells, which projected into the molecular layer, were short compared to those in the control group. In brief, our present results show that low dosage (10 ng/kg) TeT treatment apparently decreased cell proliferation and neuroblast differentiation in the mouse hippocampal DG without distinct gliosis as well as any loss of adult neurons.

Quantification of Fas protein in CSF of patients with neurocysticercosis / Quantificação da proteína Fas no LCR de pacientes com neurocisticercose

Neurocysticercosis is a parasitic disease that affects the central nervous system. The objective of this study was to investigate the correlation between neuronal death evaluated by the quantification of Fas apoptotic factor and the different evolutive forms of neurocysticercosis accompanied or not by epileptic seizures. METHODS: Cerebrospinal fluid samples from 36 patients with a diagnosis of neurocysticercosis divided into the following groups: active cystic form (n=15), 9 patients with and 6 without seizures, and calcified form (=21), 9 with and 12 without seizures. Fourteen patients comprised the control group. Fas protein concentrations were determined by ELISA. RESULTS: Only the group of patients with calcified cysts without seizures presented cerebrospinal fluid levels of Fas similar to those of the control group. Higher levels were observed for the other groups. CONCLUSIONS: The present finding suggests high cerebrospinal fluid levels of soluble Fas protein, except for patients with calcified cysts without seizures. Significant differences were observed for the group with calcified cysts and seizures, suggesting greater neuronal damage in these patients. Replacement of the term inactive cyst with reactive inactive cyst is suggested.

Neurocisticercose é uma doença parasitária que afeta o sistema nervoso central. O objetivo deste estudo foi investigar a correlação entre morte neuronal por meio da quantificação do fator apoptótico Fas e a presença de neurocisticercose nas suas diferentes fases evolutivas, acompanhadas ou não de crises epilépticas. MÉTODOS: Foram analisadas amostras de líquido cefalorraquidiano em 36 pacientes com diagnóstico de neurocisticercose, determinando-se as concentrações da proteína Fas pelo método ELISA. Foram considerados os seguintes grupos: forma cística ativa n=15 (9 com crises, 6 sem crises), forma calcificada n=21 (9 com crises, 12 sem crises) e 14 pacientes (grupo controle). RESULTADOS: Apenas o grupo com calcificações sem crises apresentou níveis de Fas semelhantes ao controle. Maiores níveis foram observados nos outros grupos. CONCLUSÕES: As formas ativa e calcificada apresentam níveis elevados da proteína Fas, exceto para as formas calcificadas sem crises. No grupo de calcificações com crise, observamos diferenças mais expressivas, sugerindo maior dano neuronal. Sugerimos a substituição da denominação "cisto inativo" por "cisto inativo reagente".

Neuronal damage and memory deficits after seizures are reversed by ascorbic acid? / O dano neuronal e o déficit de memória após convulsões são revertidos pelo ácido ascórbico?

The objective of the present study was to evaluate the neuroprotective effects of ascorbic acid (AA) in rats, against the neuronal damage and memory deficit caused by seizures. Wistar rats were treated with 0.9 percent saline (i.p., control group), ascorbic acid (500 mg/kg, i.p., AA group), pilocarpine (400 mg/kg, i.p., pilocarpine group), and the association of ascorbic acid (500 mg/kg, i.p.) plus pilocarpine (400 mg/kg, i.p.), 30 min before of administration of ascorbic acid (AA plus pilocarpine group). After the treatments all groups were observed for 24 h. Pilocarpine group presented seizures which progressed to status epilepticus in 75 percent of the animals. Pretreatment with AA led to a reduction of 50 percent of this rate. Results showed that pretreatment with AA did not alter reference memory when compared to a control group. In the working memory task, we observed a significant day's effect with important differences between control, pilocarpine and AA plus pilocarpine groups. Pilocarpine and AA plus pilocarpine groups had 81 and 16 percent of animals with brain injury, respectively. In the hippocampus of pilocarpine animals, it was detected an injury of 60 percent. As for the animals tested with AA plus pilocarpine, the hippocampal region of the group had a reduction of 43 percent in hippocampal lesion. Our findings suggest that seizures caused cognitive dysfunction and neuronal damage that might be related, at least in part, to the neurological problems presented by epileptic patients. AA can reverse cognitive dysfunction observed in rats with seizures as well as decrease neuronal injury in rat hippocampus.

O objetivo do presente estudo foi avaliar o efeito neuroprotetor do ácido ascórbico (AA), contra o dano neuronal e o déficit de memória em ratos causados pelas convulsões. Ratos Wistar foram tratados com solução salina a 0,9 por cento (i.p., grupo controle), ácido ascórbico (500 mg/kg, i.p., grupo AA), pilocarpina (400 mg/kg, i.p., grupo pilocarpina), e a associação de ácido ascórbico (500 mg/kg, i.p.) com pilocarpina (400 mg/kg, i.p.), 30 min após a administração de ácido ascórbico (AA + pilocarpina grupo). Após os tratamentos todos os grupos foram observados durante 24 h. O grupo pilocarpina apresentou crises convulsivas que evoluíram para o estado de mal epiléptico em 75 por cento dos animais. O pré-tratamento com AA produz uma redução de 50 por cento nesta taxa. Os resultados mostraram que o pré-tratamento com AA não alterou a memória em relação ao controle. No teste de memória, observou-se um efeito significativo nos dias avaliados entre os grupos controle, pilocarpina e AA + pilocarpina. 81 e 16 por cento dos animais dos grupos AA + pilocarpina e pilocarpina apresentaram danos cerebrais, respectivamente. No hipocampo dos animais do grupo pilocarpina, que foi detectada uma lesão de hipocampal de 60 por cento. Quanto aos animais do grupo AA + pilocarpina, a região do hipocampo apresentou uma redução de 43 por cento na extensão da lesão no hippocampo. Nosso resultados sugerem que as convulsões produzem disfunção cognitiva e dano neuronal que podem estar relacionados, pelo menos em parte, aos problemas neurológicos apresentados pelos pacientes epilépticos. O ácido ascórbico pode reverter essa disfunção cognitiva observado em ratos convulsivos, bem como reduz o desenvolvimento da lesão neuronal no hipocampo de ratos.

Ações neuroprotetoras da vitamina C no corpo estriado de ratos após convulsões induzidas pela pilocarpina / Neuroprotective actions of vitamin C in rat striatum after pilocarpine-induced seizures

CONTEXTO: As convulsões podem produzir danos neuronais em diversas áreas e, especialmente, nas estruturas límbicas. OBJETIVOS: O objetivo do presente trabalho foi estudar os efeitos neuroprotetores da vitamina C nas alterações histopatológicas observadas no corpo estriado de ratos convulsivos. MATERIAL E MÉTODOS: Foram utilizados ratos Wistar adultos. Os animais foram divididos em quatro grupos. O primeiro grupo foi tratado com salina 0,9 por cento (grupo controle) e o segundo, com pilocarpina (400 mg/kg, grupo P400). Já o terceiro e o quarto grupo foram tratados com vitamina C (250 mg/kg), e, 30 minutos depois, receberam P400 (grupo VIT C + P400) ou solução salina 0,9 por cento (grupo VIT C), respectivamente. Após os tratamentos, todos os grupos foram observados por 24 horas e, em seguida, sacrificados e seus cérebros removidos para as análises histopatológicas. RESULTADOS: O grupo P400 apresentou convulsões que progrediram para o estado epiléptico em 75 por cento dos animais. O pré-tratamento com vitamina C produziu uma redução de 35 por cento nesse índice. Os grupos P400 e VIT C + P400 apresentaram 80 por cento e 20 por cento de animais com lesão cerebral, respectivamente. No corpo estriado dos animais do grupo P400, houve um comprometimento de 50 por cento. Por sua vez, na região estriatal dos animais do grupo VIT C + P400 foi vista uma redução de 40 por cento nesse comprometimento. DISCUSSÃO: As convulsões induzidas pela pilocarpina são instaladas pelo sistema colinérgico e propagadas pela produção de radicais livres e pelo sistema glutamatérgico, resultado no desenvolvimento de dano cerebral. As drogas antioxidantes podem apresentar um potencial terapêutico para pacientes epilépticos na proteção contra as lesões cerebrais por meio da remoção desses radicais livres formados. Acredita-se, assim, que a vitamina C pode influenciar a epileptogênese e promover ações neuroprotetoras durante as convulsões.

BACKGROUND: Seizures may produce neuronal damage in several areas and especially in limbic structures. OBJECTIVES: This study aimed to evaluate the neuroprotective effects of vitamin C in the histopathological changes observed in rat striatum after seizures. MATERIAL AND METHODS: Healthy Wistar rats were divided into four groups. The first group was treated with 0.9 percent saline (control group) and the second one with pilocarpine (400 mg/kg, P400 group). Third and fourth groups were treated with vitamin C (250 mg/kg), 30 minutes before receiving P400 (P400 + VIT C group) or 0.9 percent saline (VIT C group), respectively. After the treatments, all groups were observed for 24 hours, sacrificed and dissected out to remove their brains for histopathological analysis. RESULTS: The group P400 presented seizures that progressed to status epilepticus in 75 percent of the animals. Pretreatment with vitamin C produced a 35 percent reduction in this index. P400 and P400 + VIT C groups revealed 80 percent and 20 percent of animals with brain injury, respectively. In P400 group, lesion severity of the striatum was 50 percent. In turn, in striatal region of animals treated with P400 + VIT C group, we detected a reduction of 40 percent in the severity degree. DISCUSSION: Pilocarpine-induced seizures are installed by the cholinergic system and propagated by free radicals and by glutamatergic system, leading to brain damage. The antioxidant drugs may have therapeutic potential for epileptic patients to protect against brain injure through removing free radicals produced, suggesting that vitamin C may influence epileptogenesis and promote neuroprotective actions during seizures.

Systemic LPS administration induces brain inflammation but not dopaminergic neuronal death in the substantia nigra

It has been suggested that brain inflammation is important in aggravation of brain damage and/or that inflammation causes neurodegenerative diseases including Parkinson's disease (PD). Recently, systemic inflammation has also emerged as a risk factor for PD. In the present study, we evaluated how systemic inflammation induced by intravenous (iv) lipopolysaccharides (LPS) injection affected brain inflammation and neuronal damage in the rat. Interestingly, almost all brain inflammatory responses, including morphological activation of microglia, neutrophil infiltration, and mRNA/protein expression of inflammatory mediators, appeared within 4-8 h, and subsided within 1-3 days, in the substantia nigra (SN), where dopaminergic neurons are located. More importantly, however, dopaminergic neuronal loss was not detectable for up to 8 d after iv LPS injection. Together, these results indicate that acute induction of systemic inflammation causes brain inflammation, but this is not sufficiently toxic to induce neuronal injury.

Regulation of the Activity of Tissue Plasminogen Activator and Plasminogen Activator Inhibitor-1 by Zinc in Rat Primary Astrocytes

Tissue-type plasminogen activator (tPA) is a serine proteinase which plays important roles in functional and structural synaptic plasticity, neural migration, as well as excitotoxic injuries in several pathological situations including ischemic stroke, seizure and Alzheimer's disease (AD). It has been suggested that a divalent cation zinc also plays pathological roles in ischemia and seizure. Interestingly, it has been suggested that zinc and tPA may negatively regulate the activity or the level of each other by mechanism involving physical interaction between the two. In the present study, we investigated the effect of zinc in tPA activity and expression in rat primary astrocyte. Astrocytes were transiently exposed to 20~200micrometer Zn2+ for 2 h and then were recovered for 24 h. In the culture supernatants, zinc treatment concentration-dependently inhibited the activity of tPA which was determined by casein-plasminogen zymography. There was only marginal changes, if any, in the level of tPA mRNA and protein. On the other hand, the activity of an endogenous inhibitor of tPA, plasminogen activator inhibitor-1 (PAI-1) as well as its expression was increased by zinc treatment in a concentration-dependant manner. These results suggest that zinc-induced decrease in tPA activity was also, at least in part, regulated by indirect way by regulating the level of PAI-1. The decrease in tPA activity may be a part of body's plan to reduce excitotoxic neural injury in a condition of elevated zinc in the brain.