RESUMEN
Intracerebral hemorrhage (ICH) is a severe stroke subtype caused by the rupture of blood vessels within the brain. Increased levels of S100B protein may contribute to neuroinflammation after ICH through activation of astrocytes and resident microglia, with the consequent production of proinflammatory cytokines and reactive oxygen species (ROS). Inhibition of astrocytic synthesis of S100B by arundic acid (AA) has shown beneficial effects in experimental central nervous system disorders. In present study, we administered AA in a collagenase-induced ICH rodent model in order to evaluate its effects on neurological deficits, S100B levels, astrocytic activation, inflammatory, and oxidative parameters. Rats underwent stereotactic surgery for injection of collagenase in the left striatum and AA (2 µg/µl; weight × 0.005) or vehicle in the left lateral ventricle. Neurological deficits were evaluated by the Ladder rung walking and Grip strength tests. Striatal S100B, astrogliosis, and microglial activation were assessed by immunofluorescence analysis. Striatal levels of interleukin 1ß (IL-1ß) and tumor necrosis factor α (TNF-α) were measured by ELISA, and the ROS production was analyzed by dichlorofluorescein (DCF) oxidation. AA treatment prevented motor dysfunction, reduced S100B levels, astrogliosis, and microglial activation in the damaged striatum, thus decreasing the release of proinflammatory cytokines IL-1ß and TNF-α, as well as ROS production. Taken together, present results suggest that AA could be a pharmacological tool to prevent the harmful effects of increased S100B, attenuating neuroinflammation and secondary brain damage after ICH.
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Trastornos Motores , Enfermedades Neuroinflamatorias , Animales , Caprilatos/farmacología , Hemorragia Cerebral/complicaciones , Hemorragia Cerebral/tratamiento farmacológico , Hemorragia Cerebral/metabolismo , Microglía/metabolismo , Trastornos Motores/complicaciones , RatasRESUMEN
BACKGROUND: The aim of this study was to investigate serum S100B and brain-derived neurotrophic factor (BDNF) in systemic lupus erythematous (SLE) patients, with and without neuropsychiatric (NP) manifestation activity. METHODS: We assessed 47 SLE patients and 20 selected healthy individuals. Disease activity was assessed according to the SLE disease activity index (SLEDAI). Serum BDNF and S100B were measured by enzyme-linked immunosorbent assay. RESULTS: Serum S100B protein was significantly higher in SLE patients. BDNF levels were significantly decreased in active SLE, when compared with inactive SLE, but not when compared with controls. S100B was clearly higher in the NPSLE group, when compared with the non-NPSLE or control groups. Receiver operating characteristic analysis of S100B revealed an area under the curve of 0.706 that discriminated NPSLE patients with peripheral polyneuropathy. CONCLUSIONS: Our findings reinforce the use of serum S100B as a biomarker in SLE, particularly for NPSLE. Moreover, we found a strong association between serum S100B and peripheral neuropathy, indicating a specific utility for this biomarker in SLE that warrants clinical investigation.
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Factor Neurotrófico Derivado del Encéfalo/sangre , Vasculitis por Lupus del Sistema Nervioso Central/sangre , Subunidad beta de la Proteína de Unión al Calcio S100/sangre , Adulto , Biomarcadores/sangre , Estudios de Casos y Controles , Cuba , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Vasculitis por Lupus del Sistema Nervioso Central/inmunología , Masculino , Persona de Mediana Edad , Curva ROC , Índice de Severidad de la EnfermedadRESUMEN
The inflammatory hypothesis of schizophrenia (SZ) posits that inflammatory processes and neural-immune interactions are involved in its pathogenesis, and may underpin some of its neurobiological correlates. SZ is the psychiatric disorder causing the most severe burden of illness, not just owing to its psychiatric impairment, but also owing to its significant medical comorbidity. C-reactive protein (CRP) is a commonly used biomarker of systemic inflammation worldwide. There are some conflicting results regarding the behaviour of CRP in SZ. The aims of this study were to verify whether peripheral CRP levels are indeed increased in SZ, whether different classes of antipsychotics divergently modulate CRP levels and whether its levels are correlated with positive and negative symptomatology. With that in mind, we performed a meta-analysis of all cross-sectional studies of serum and plasma CRP levels in SZ compared to healthy subjects. In addition, we evaluated longitudinal studies on CRP levels before and after antipsychotic use. Our meta-analyses of CRP in SZ included a total of 26 cross-sectional or longitudinal studies comprising 85 000 participants. CRP levels were moderately increased in persons with SZ regardless of the use of antipsychotics and did not change between the first episode of psychosis and with progression of SZ (g=0.66, 95% confidence interval (95% CI) 0.43 to 0.88, P<0.001, 24 between-group comparisons, n=82 962). The extent of the increase in peripheral CRP levels paralleled the increase in severity of positive symptoms, but was unrelated to the severity of negative symptoms. CRP levels were also aligned with an increased body mass index. Conversely, higher age correlated with a smaller difference in CRP levels between persons with SZ and controls. Furthermore, CRP levels did not increase after initiation of antipsychotic medication notwithstanding whether these were typical or atypical antipsychotics (g=0.01, 95% CI -0.20 to 0.22, P=0.803, 8 within-group comparisons, n=713). In summary, our study provides further evidence of the inflammatory hypothesis of SZ. Whether there is a causal relationship between higher CRP levels and the development of SZ and aggravation of psychotic symptoms, or whether they are solely a marker of systemic low-grade inflammation in SZ, remains to be clarified.
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Antipsicóticos/uso terapéutico , Proteína C-Reactiva/metabolismo , Esquizofrenia/sangre , Esquizofrenia/tratamiento farmacológico , Biomarcadores/sangre , Estudios de Casos y Controles , Estudios Transversales , Humanos , Estudios LongitudinalesRESUMEN
An ideal amino acid ratio (IAAR) for breeder hens is needed for maximum nitrogen retention (NR) taking into account nitrogen deposition in body (NDB ), feathers (NDF ) and egg mass (NEM) to improve dietary protein efficiency. Thus, the aim of this study was to apply the deletion method to derive the IAAR for broiler breeder hens. The nitrogen balance trials were performed from 31 to 35 weeks and from 46 to 50 weeks. Twelve treatments with eight replicates and one hen per cage were used. A balanced diet (BD) was formulated to meet the requirement of all nutrients. The other diets were formulated diluting 55% of BD with corn starch and refilled with amino acids (AAs) and other ingredients, except the AA tested. Each trial lasted 25 days. Feather losses, egg production and egg weight were recorded daily, and the samples were stored to further determine NEM and nitrogen in feather losses (NDFL ). At the start and the end of each period, a group of birds were slaughtered to further determine NDB and NDF . The NR was calculated as the sum of NDB , NDF , NDFL , NEM and the nitrogen maintenance requirement (NMR). The deletion of valine greatly depressed the NR in peak production (31 to 35 weeks) while the deletion of the isoleucine greatly depressed the NR of the hens from 46 to 50 weeks of age. The percentual reduction in NR and the per cent of the AA to delete from the BD were used to calculate the AA requirement. The average IAAR was Lys 100, Met+Cys 86, Trp 23, Thr 80, Arg 113, Val 90, Ile 91, Leu 133, Phe+Tyr 108, Gly+Ser 94 and His 35. The IAAR was in line with the recommendation from the literature, validating deletion method with the advantages from a rapid and low-cost procedure.
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Aminoácidos/administración & dosificación , Alimentación Animal/análisis , Pollos/fisiología , Dieta/veterinaria , Proteínas en la Dieta/administración & dosificación , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Relación Dosis-Respuesta a Droga , Plumas , Femenino , Nitrógeno , Necesidades Nutricionales , OviposiciónRESUMEN
It has been postulated that schizophrenia (SZ) is related to a lower expression of brain-derived neurotrophic factor (BDNF). In the past few years, an increasing number of divergent clinical studies assessing BDNF in serum and plasma have been published. It is now possible to verify the relationship between BDNF levels and severity of symptoms in SZ as well as the effects of antipsychotic drugs on BDNF using meta-analysis. The aims of this study were to verify if peripheral BDNF is decreased in SZ, whether its levels are correlated with positive and negative symptomatology and if BDNF levels change after antipsychotic treatment. This report consists of two distinct meta-analyses of peripheral BDNF in SZ including a total of 41 studies and more than 7000 participants: (1) peripheral BDNF levels in serum and plasma were moderately reduced in SZ compared with controls. Notably, this decrease was accentuated with the disease duration. However, the extent of peripheral BDNF level decrease did not correlate with the severity of positive and negative symptoms. (2) In plasma, but not serum, peripheral BDNF levels are consistently increased after antipsychotic treatment irrespective of the patient's response to medication. In conclusion, there is compelling evidence that there are decreased levels of peripheral BDNF in SZ, in parallel to previously described reduced cerebral BDNF expression. It remains unclear whether these systemic changes are causally related to the development of SZ or if they are merely a pathologic epiphenomenon.
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Antipsicóticos/uso terapéutico , Factor Neurotrófico Derivado del Encéfalo/sangre , Esquizofrenia/sangre , Esquizofrenia/tratamiento farmacológico , Adulto , Biomarcadores/sangre , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
Plants such as Annona nutans used in folk medicine have a large number of biologically active compounds with pharmacological and/or toxic potential. Moreover, pregnant women use these plants indiscriminately, mainly in the form of teas, without being aware of the harm that they could cause to the health of the embryo/fetus. Therefore, it is necessary to analyze the potential toxic effects of medicinal plants during gestation. The present study aimed to evaluate the effects of A. nutans hydromethanolic fraction leaves (ANHMF) on mutagenic and immunomodulatory activity, reproductive performance, and embryo-fetal development in pregnant female mice. The animals (N=50 female and 25 male) were divided into 5 groups: Control, Pre-treatment, Organogenesis, Gestational, and Pre+Gestational. The results indicate that ANHMF mainly contains flavonoid and other phenolic derivatives. It was found that it does not exhibit any mutagenic or immunomodulatory activity, and it does not cause embryo-fetal toxicity. Based on the protocols used in the present studies, our analyses confirm that it is safe to use ANHMF during pregnancy.
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Annona/química , Desarrollo Fetal/efectos de los fármacos , Extractos Vegetales/efectos adversos , Reproducción/efectos de los fármacos , Bazo/efectos de los fármacos , Animales , Femenino , Masculino , Ratones , Pruebas de Micronúcleos , Extractos Vegetales/administración & dosificación , Plantas Medicinales/química , EmbarazoRESUMEN
It has been proposed that animals subjected to chronic stress show a stress response that can be reduced by the intake of highly palatable foods ("comfort foods"). However, a palatable diet, rich in sugar or fat, can also lead to oxidative damage and neuronal injury. So, the aim of this study is to verify, in male and female rats, the effects of exposure to chronic stress during free access to regular chow and to a highly palatable diet, on exploratory and anxiety-like behavior, on oxidative stress and on DNA breaks in two structures of the nervous system, hippocampus and striatum. The results showed stress- and diet-induced DNA breaks and an imbalance in the activity of antioxidants enzymes, such as CAT, GPx and SOD in the both structures. In addition, we observed that female rats appear to have higher susceptibility to the stress effects evaluated, and that access to a palatable diet was able to counteract some behavioral effects of stress. However, this same diet-induced oxidative stress and increased DNA breaks, especially in males. Replication of these results with larger sample sizes would further reinforce these conclusions.
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Ansiedad/prevención & control , Ingestión de Alimentos , Alimentos , Estrés Oxidativo/fisiología , Estrés Psicológico/fisiopatología , Estrés Psicológico/psicología , Animales , Conducta Animal/fisiología , Cacao , Cuerpo Estriado/fisiopatología , Daño del ADN , Conducta Exploratoria , Femenino , Hipocampo/fisiopatología , Masculino , Ratas , Ratas Wistar , Restricción Física , Factores Sexuales , Estrés Psicológico/prevención & controlRESUMEN
Stroke is one of the leading causes of mortality and neurological morbidity. Intracerebral hemorrhage (ICH) has the poorest prognosis among all stroke subtypes and no treatment has been effective in improving outcomes. Following ICH, the observed high levels of S100B protein have been associated with worsening of injury and neurological deficits. Arundic acid (AA) exerts neuroprotective effects through inhibition of astrocytic synthesis of S100B in some models of experimental brain injury; however, it has not been studied in ICH. The aim of this study was to evaluate the effects of intracerebroventricular (ICV) administration of AA in male Wistar rats submitted to ICH model assessing the following variables: reactive astrogliosis, S100B levels, antioxidant defenses, cell death, lesion extension and neurological function. Firstly, AA was injected at different doses (0.02, 0.2, 2 and 20⯵g/µl) in the left lateral ventricle in order to observe which dose would decrease GFAP and S100B striatal levels in non-injured rats. Following determination of the effective dose, ICH damage was induced by IV-S collagenase intrastrial injection and 2⯵g/µl AA was injected through ICV route immediately before injury. AA treatment prevented ICH-induced neurological deficits and tissue damage, inhibited excessive astrocytic activation and cellular apoptosis, reduced peripheral and central S100B levels (in striatum, serum and cerebrospinal fluid), improved neuronal survival and enhanced the antioxidant defences after injury. Altogether, these results suggest that S100B is a viable target for treating ICH and highlight AA as an interesting strategy for improving neurological outcome after experimental brain hemorrhage.
Asunto(s)
Lesiones Encefálicas , Fármacos Neuroprotectores , Animales , Caprilatos , Hemorragia Cerebral/complicaciones , Hemorragia Cerebral/tratamiento farmacológico , Modelos Animales de Enfermedad , Masculino , Fármacos Neuroprotectores/farmacología , Ratas , Ratas Wistar , Subunidad beta de la Proteína de Unión al Calcio S100RESUMEN
Physical training induces beneficial adaptations; however, exhausting exercise increases reactive oxygen species generation, resulting in damage to DNA and tissues. Pequi (Caryocar brasiliense), a fruit of the Brazilian Cerrado, contains a carotenoid-rich oil. We investigated whether pequi oil had antioxidant effects in runners. Evaluations were made after outdoor races before and after ingestion of 400 mg pequi-oil capsules for 14 days. Blood samples were taken after races and submitted to comet and TBARS assays and biochemical analyses of creatine kinase (CK), aspartate aminotransferase (AST) and alanine aminotransferase (ALT). To determine if the protective effects of pequi-oil were influenced by antioxidant enzyme genotypes, MnSOD (-Val9Ala), CAT (-21A/T) and GPX1 (Pro198Leu) gene polymorphisms were also investigated. Pequi oil was efficient in reducing tissue injuries evaluated for AST and ALT, particularly in women, and in reducing DNA damages in both sexes. Except for CK levels, the results were influenced by MnSOD genotypes; heterozygous excess was related to less DNA damage, tissue injury and lipid peroxidation, besides presenting a better response to pequi oil against exercise-induced damage.
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Alanina/genética , Carotenoides/análisis , Daño del ADN/efectos de los fármacos , Dieta , Peroxidación de Lípido/efectos de los fármacos , Aceites de Plantas/farmacología , Polimorfismo Genético , Carrera , Superóxido Dismutasa/genética , Valina/genética , Adolescente , Adulto , Humanos , Aceites de Plantas/química , Superóxido Dismutasa/químicaRESUMEN
INTRODUCTION: Perinatal hypoxia-ischemia (HI) is one of the main causes of mortality and chronic neurological morbidity in infants and children. Astrocytes play a key role in HI progression, becoming reactive in response to the injury, releasing S100 calcium binding protein B (S100B). Since S100B inhibition seems to have neuroprotective effects on central nervous system injury models, here we evaluated the neuroprotective effects of an S100B inhibitor, arundic acid (AA) in a HI model. METHODS: On the 7th postnatal day, animals were submitted to the combination of common carotid artery occlusion and hypoxic atmosphere (8% O2) for 60â¯min. Three experiments were performed in order to: (1) define AA dose (0.1, 1 or 10â¯mg/kg, pre-hypoxia i.p. injection), (2) test if repeated AA administrations (10â¯mg/kg at 3 time points: Pre-hypoxia, 24â¯h and 48â¯h after HI) would improve the response and (3) investigate biochemical mechanisms involved in AA protection two days after HI. RESULTS: AA at a dose of 10â¯mg/kg applied before and after hypoxia, was the only treatment protocol that was able to improve HI-induced memory deficits, to reduce tissue damage, to promote astrocytic survival in the hippocampus and to reduced extracellular release of S100B in the cerebrospinal fluid. CONCLUSION: Overall, AA treatment showed beneficial effects on memory deficits, tissue damage, promoting astrocyte survival likely by reducing S100B release. Protection aided to astrocytes by AA treatment against HI lesion may lead to development of new therapeutic strategies that target these particular cells.
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Astrocitos/efectos de los fármacos , Caprilatos/farmacología , Hipoxia-Isquemia Encefálica/complicaciones , Trastornos de la Memoria/prevención & control , Fármacos Neuroprotectores/farmacología , Animales , Animales Recién Nacidos , Astrocitos/patología , Encéfalo/patología , Supervivencia Celular/efectos de los fármacos , Proteína Ácida Fibrilar de la Glía/metabolismo , Glutamato-Amoníaco Ligasa/metabolismo , Hipoxia-Isquemia Encefálica/patología , Aprendizaje por Laberinto/efectos de los fármacos , Trastornos de la Memoria/etiología , Ratas , Subunidad beta de la Proteína de Unión al Calcio S100/antagonistas & inhibidores , Subunidad beta de la Proteína de Unión al Calcio S100/metabolismoRESUMEN
Neonatal hypoxia ischemia (HI) plays a role in the etiology of several neurological pathologies and causes severe sequelae. Acetylcholine is a neurotransmitter in the central nervous system and cholinesterase inhibitors have demonstrated a positive action over HI induced deficits. In order to evaluate the effects of pre and post-hypoxia administrations of galantamine, a cholinesterase inhibitor, in a model of perinatal HI, Wistar rats in the post-natal day 7 (PND7) were subjected to a combination of unilateral occlusion of the right carotid artery with the exposure to a 1h hypoxia. Intraperitoneal injections of galantamine were administered in two different protocols: one pre and other post-hypoxia. The analysis of brain structures volume at PND45 showed that pre-hypoxia galantamine treatment prevented tissue injury to the ipsilesional hippocampus. Also, immunofluorescence showed HI-induced increase in the number of astrocytes that was prevented by pre-hypoxia treatment. Biochemical analysis was performed in the ipsilesional hippocampus at PND8 and revealed that pre-hypoxia galantamine treatment: 1) prevented the neuronal loss induced by HI; 2) reduced the HI-induced hypertrophy of astrocytes; and 3) caused an increase in the activity of the anti-oxidant enzyme catalase. Overall, treatment with galantamine was able to prevent the brain damage, increase the survival of neurons, reduce astrocytic reaction and increase the activity of the anti-oxidant enzyme catalase in rats submitted to neonatal hypoxia ischemia.
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Encéfalo , Catalasa/metabolismo , Inhibidores de la Colinesterasa/administración & dosificación , Galantamina/administración & dosificación , Gliosis/prevención & control , Hipoxia-Isquemia Encefálica/tratamiento farmacológico , Regulación hacia Arriba/efectos de los fármacos , Factores de Edad , Animales , Animales Recién Nacidos , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Encéfalo/fisiología , Esquema de Medicación , Femenino , Fluoresceínas/metabolismo , Proteína Ácida Fibrilar de la Glía/metabolismo , Hipoxia-Isquemia Encefálica/patología , Masculino , Ratas , Ratas Wistar , Especies de Nitrógeno Reactivo/metabolismo , Subunidad beta de la Proteína de Unión al Calcio S100/metabolismo , Superóxido Dismutasa/metabolismoRESUMEN
Striatum and the cerebral cortex are regions susceptible to secondary injury after intracerebral hemorrhage (ICH) and glial cells in tissue adjacent to the hematoma may modulate cellular vulnerability after brain damage. Nonetheless, while the glial- associated changes occurring in the cerebral cortex after ICH may be important in maximizing brain recovery, they are not fully understood. The aim of this study was to evaluate the temporal profile of glial-associated changes in the cerebral cortex after ICH. First, the motor consequences of ICH and its relation to the lesion volume were analyzed. Secondly, glial cell proportion (GFAP+ and S100B+ astrocytes, CD11+ microglia) in the ipsilesional sensorimotor cortex and striatum, using flow cytometry were evaluated. ELISA was used to measure GFAP and S100B content in these structures as well as S100B levels in serum and cerebral spinal fluid. Main results revealed that ICH induced a delayed increase in GFAP+ cells in the sensorimotor cortex, as compared to the striatum, although the pattern of GFAP expression was similar in both structures. Interestingly, the time-curve patterns of both S100B and CD11+ microglial cells differed between the cortex and striatum. Altogether, these results suggest a different dynamics of glial-associated changes in the cerebral cortex, suggesting it is a vulnerable structure and undergoes an independent secondary process of reactive glial plasticity following intracerebral hemorrhage.
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Corteza Cerebral/patología , Hemorragia Cerebral/patología , Cuerpo Estriado/patología , Neuroglía/patología , Animales , Corteza Cerebral/fisiopatología , Hemorragia Cerebral/fisiopatología , Colagenasas , Cuerpo Estriado/fisiopatología , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Miembro Anterior/fisiopatología , Proteína Ácida Fibrilar de la Glía/metabolismo , Masculino , Actividad Motora , Trastornos del Movimiento/patología , Trastornos del Movimiento/fisiopatología , Fuerza Muscular , Neuroglía/fisiología , Ratas Wistar , Subunidad beta de la Proteína de Unión al Calcio S100/metabolismoRESUMEN
This work presents a study on the influence of the aqueous environment on the surface EMG (sEMG) signal recorded in bipolar montage from the abductor pollicis brevis muscle, when only the forearm is immersed in water. Ten men, 30.1+/-4.0 (mean +/- SD) years old, performed ten 2-s 40% MVC isometric contractions of the abductor pollicis brevis muscle in two controlled environments (air and water, at a temperature of 32 degrees C). They were always equipped with electrodes protected with a waterproof adhesive tape. No significant variations (paired Wilcoxon test) due to the environments were observed in the median frequency of the power spectrum (MDF) and in the root mean square (RMS) value of the sEMG signal. These results allow us to assess the methodological criteria to properly record sEMG signals in water and provide the basis to explain different findings obtained by other authors.
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Electromiografía/normas , Músculo Esquelético/fisiología , Procesamiento de Señales Asistido por Computador , Adulto , Aire , Electromiografía/métodos , Antebrazo , Humanos , Contracción Isométrica , Masculino , Estadísticas no Paramétricas , AguaRESUMEN
BACKGROUND: Bipolar disorder (BD) is a psychiatric disorder associated with increased rates of obesity and inflammation. Leptin is an adipokine that is mainly produced by the white adipose tissue in response to insulin. It stimulates the immune system, increasing the production of pro-inflammatory cytokines. There is currently uncertainty regarding possible alterations in peripheral leptin levels across the mood states in BD. METHODS: This study comprises a between-group meta-analysis comparing serum and plasma leptin levels in people with BD in mania, depression or euthymia and healthy controls. We conducted a systematic search for all possibly eligible-English and non-English peer-reviewed articles. We calculated the effect size (ES) utilizing Hedges' adjusted g using random effects. RESULTS: Eleven studies were included in the meta-analyses, providing data on 1118 participants. Serum and plasma leptin levels were not altered in subjects with BD when compared to healthy controls in mania (g=-0.99, 95% CI -2.43 to 0.43, P=0.171), in depression (g=0.17, 95% CI -0.45 to 0.79, P=0.584), or in euthymia (g=0.03, 95% CI -0.39 to 0.46, P=0.882). However, we did observe a stronger association between leptin levels and both age and BMI in patients with BD in euthymia compared to healthy controls, such that the greater the age of the individuals, the greater the difference in leptin levels between BD and controls; and the higher the BMI, the greater the difference in leptin levels between BD and controls. CONCLUSIONS: Our meta-analysis provides evidence that leptin levels are not altered in BD across the mood spectrum compared to healthy controls. The disproportionate increase of leptin levels with increase in BMI in BD speaks in favour of a potential inflammatory role of white adipose tissue in BD and a disproportionate increase of leptin levels with increase in age.
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Trastorno Bipolar/sangre , Leptina/sangre , Adulto , Trastorno Ciclotímico/sangre , Depresión/sangre , Femenino , Humanos , MasculinoRESUMEN
S100B, a calcium binding protein physiologically produced and released by astrocytes, has been used as a peripheral marker of brain damage. Here, we investigated the effects of subcutaneous injections of methylmercury chloride (MeHg-5mg/kg), an environmental neurotoxicant, on S100B protein content in cerebrospinal fluid (CSF) of adult rats. In addition, the performance of animals in an open field (number of squares crossing and rearings) was also analyzed in order to obtain a possible link between alteration in S100B protein content in CSF and parameters related to neurological injury. MeHg treatment increased serum mercury and S100B protein levels in the CSF. A decrease in the numbers of crossings and rearings was observed in MeHg-treated animals when compared to control group, which suggests a possible neurological injury. The present data show, for the first time, increased S100B levels in CSF after exposure to a neurotoxic metal. Authors discuss the possibility of astrocytic involvement in MeHg-induced neurotoxicity.
RESUMEN
Primary astrocyte cultures prepared from neonatal hippocampus, cerebral cortex and cerebellum were morphologically distinct. Cells from hippocampus and cortex were almost entirely protoplasmic, whereas cerebellar astrocytes had many processes; in the absence of serum these differences were accentuated. We compared the immunocontent and secretion of the mitogenic protein S100B in these cultures. Immunocontent was 2.5 times higher in cerebellar astrocytes than in hippocampal or cortical astrocytes. Cells from all three regions secreted S100B under basal conditions, but the secretion rate was higher in cerebellar astrocytes. Secretion depended on protein synthesis and was increased by incubation with forskolin or lysophosphatidic acid in mechanisms which were additive. The stellate morphology induced by forskolin was reversed by lysophosphatidic acid in hippocampal but not in cerebellar cultures, suggesting that S100B secretion was not associated with a process-bearing phenotype of astrocytes.
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Astrocitos/metabolismo , Proteínas de Unión al Calcio/metabolismo , Cerebelo/metabolismo , Corteza Cerebral/metabolismo , Hipocampo/metabolismo , Factores de Crecimiento Nervioso/metabolismo , Proteínas S100 , Animales , Astrocitos/citología , Astrocitos/efectos de los fármacos , Diferenciación Celular , Cerebelo/citología , Cerebelo/efectos de los fármacos , Corteza Cerebral/citología , Corteza Cerebral/efectos de los fármacos , Colforsina/farmacología , Proteína Ácida Fibrilar de la Glía/metabolismo , Hipocampo/citología , Hipocampo/efectos de los fármacos , Inmunohistoquímica , Lisofosfolípidos/farmacología , Fenotipo , Ratas , Ratas Wistar , Subunidad beta de la Proteína de Unión al Calcio S100RESUMEN
The S100 proteins are a family of calcium-binding proteins found in the central and peripheral nervous systems of vertebrates. S100beta, the most abundant member of this family in the CNS, mediates calcium signal transduction, and shows neurotrophic, gliotrophic and mitogenic actions that influence the development and maintenance of the nervous system. Another member of the S100 family (S100A10) was found to modulate phospholipid turnover by inhibiting the activity of enzyme phospholipase A2 (PLA2). We determined the concentration of S100beta protein in the plasma of 23 medicated schizophrenic patients and 23 healthy controls. S100beta protein accounts for 96% of the total S100 in the brain. Schizophrenic patients showed reduced S100beta concentrations (p=0.003), and this finding was not related to clinical variables or to intake of antipsychotic medication. Decreased S100beta could be related to the findings of increased PLA2 activity and to brain maldevelopment in schizophrenia. These results are discussed further with respect to the role of adenosine in S100beta release.
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Proteínas S100/sangre , Esquizofrenia/fisiopatología , Adulto , Encéfalo/fisiopatología , Citosol/enzimología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de Crecimiento Nervioso , Fosfolipasas A/fisiología , Fosfolipasas A2 , Escalas de Valoración Psiquiátrica , Valores de Referencia , Subunidad beta de la Proteína de Unión al Calcio S100 , Esquizofrenia/diagnósticoRESUMEN
S100B is a calcium binding protein expressed and secreted by astrocytes. Extracellular S100B stimulates the proliferation of astroglial cells and the survival of neurons. Extracellular signal regulated kinases (ERK) are involved in the transduction of proliferating signals in astrocytes. Here we report that S100B significantly increases the activity of ERK in primary cultures of astrocytes, a result which may be related to previous observations of the effect of this protein on glial proliferation. We further confirm that conversion of S100B to its covalent dimer by oxidation of cysteine residues increases its extracellular activity. Although we cannot exclude S100B involvement in other mechanisms of signal transduction, these results suggest that ERK activity in astrocytes is modulated by extracellular S100B.
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Astrocitos/efectos de los fármacos , Astrocitos/metabolismo , Proteínas de Unión al Calcio/metabolismo , Proteínas de Unión al Calcio/farmacología , Espacio Extracelular/metabolismo , Proteínas Quinasas Activadas por Mitógenos/efectos de los fármacos , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Factores de Crecimiento Nervioso/metabolismo , Factores de Crecimiento Nervioso/farmacología , Proteínas S100 , Animales , Animales Recién Nacidos , Técnicas de Cultivo de Célula , Ratas , Subunidad beta de la Proteína de Unión al Calcio S100 , Factores de TiempoRESUMEN
S100B protein, a calcium binding protein produced and released by glial cells, has been used as a sensitive marker of brain damage. Previous studies have found alterations in peripheral S100B levels in schizophrenic patients on medication. We compared serum S100B levels of 20 medication-free DSM-IV schizophrenic patients and 20 age-gender matched healthy controls. Schizophrenic patients presented higher serum S100B levels (mean 0.120 ng/ml+/-S.D. 0.140) compared to controls (mean 0.066 ng/ml+/-S.D. 0.067; P=0.014) and there was a negative correlation with illness duration (r=-0.496, P=0.031). The results of this study indicate that serum S100B levels may be a state marker of a limited neurodegenerative process, particularly in the early course of schizophrenia or, at least, in a subgroup of schizophrenic patients.