LDL Exposure Disrupts Mitochondrial Function and Dynamics in a Hippocampal Neuronal Cell Line.

Hypercholesterolemia has been associated with cognitive dysfunction and neurodegenerative diseases. Moreover, this metabolic condition disrupts the blood-brain barrier, allowing low-density lipoprotein (LDL) to enter the central nervous system. Thus, we investigated the effects of LDL exposure on mitochondrial function in a mouse hippocampal neuronal cell line (HT-22). HT-22 cells were exposed to human LDL (50 and 300 µg/mL) for 24 h. After this, intracellular lipid droplet (LD) content, cell viability, cell death, and mitochondrial parameters were assessed. We found that the higher LDL concentration increases LD content compared with control. Both concentrations increased the number of Annexin V-positive cells, indicating apoptosis. Moreover, in mitochondrial parameters, the LDL exposure on hippocampal neuronal cell line leads to a decrease in mitochondrial complexes I and II activities in both concentrations tested and a reduction in Mitotracker™ Red fluorescence and Mitotracker™ Red and Mitotracker™ Green ratio in the higher concentration, indicating mitochondrial impairment. The LDL incubation induces mitochondrial superoxide production and decreases superoxide dismutase activity in the lower concentration in HT-22 cells. Finally, LDL exposure increases the expression of genes associated with mitochondrial fusion (OPA1 and mitofusin 2) in the lower concentration. In conclusion, our findings suggest that LDL exposure induces mitochondrial dysfunction and modulates mitochondrial dynamics in the hippocampal neuronal cells.

O poder sobre a vida: os corpos regidos pela prática biomédica versus corpos de intensidades / The power over life: bodies governed by biomedical practice versus intensity bodies

Neste artigo, discuto a questão da materialidade organicista do corpo contra um corpo de intensidades. De acordo com Separavich e Canesqui (2010), os estudos de Marcel Mauss (2003 [1934]) e Margaret Mead (2000 [1935]) "revelou que, embora se possa atribuir uma materialidade universal ao corpo, definições, disposições corporais e seus significados são múltiplos. Como resultado dessa heterogeneidade nas formas de conceber corpo, as concepções do que seja saúde e doença também múltiplas tradições" (p. 251). De acordo com Cecil G. Helman (1994) para "os membros de todas as sociedades, o corpo humano é mais do que um simples organismo físico oscilando entre a saúde e a doença. É também o foco de um conjunto de crenças sobre seu significado social e psicológico, estrutura e funcionamento. A expressão 'imagem corporal' é usada para descrever todas as maneiras pelas quais um indivíduo conceitua e experimenta seu próprio corpo, consciente ou inconscientemente" (p. 30), variando com cada sociedade e momento histórico em que se definem: incluem crenças sobre a forma e o tamanho ideal do corpo, crenças sobre sua estrutura e crenças sobre suas funções. Pretendo refletir sobre o corpo, trazendo alguns elementos históricos para chamar a atenção para a ocorrência de certas condições ­ conhecimento médico e outros aspectos sócio-históricos ­ entrelaçada com a produção de práticas e intervenções médicas, no corpo, assim como no governo da vida, com a intenção de chamar a atenção para as práticas médicas integrativas que são a partir de uma visão do corpo de intensidades.

In this article, I discuss the issue of the organicist materiality of the body versus a body of intensities. According to Separavich and Canesqui (2010), the studies of Marcel Mauss (2003 [1934]) and Margaret Mead (2000 [1935]) "revealed that, although a universal materiality can be attributed to the body, definitions, bodily dispositions and their meanings are manifold. As a result of this heterogeneity in the ways of conceiving the body, the conceptions of what health and disease are also have multiple traditions" (p. 251). According to Cecil G. Helman (1994) for "the members of all societies, the human body is more than a simple physical organism oscillating between health and disease. It is also the focus of a set of beliefs about its social and psychological meaning, structure and functioning. The expression 'body image' is used to describe all the ways in which an individual conceptualizes and experiences his own body, consciously or unconsciously" (p. 30), varying with each society and historical moment in which they are defined: they include beliefs about ideal body shape and size, beliefs about its internal structure, and beliefs about its functions. I intend to reflect on the body, bringing some historical elements to draw attention to the occurrence of certain conditions - medical knowledge and other socio-historical aspects - intertwined with the production of medical practices and interventions, in the body, as well as in the government of life, with the intention of drawing attention to integrative medical practices that are based on a vision of the body of intensities.

Teste de Progresso: ausência de alunos de Medicina é sugestiva de mau desempenho acadêmico / Progress Test: medical student absenteeism is suggestive of poor academic performance

Resumo: Introdução: Não se sabe se a ausência de estudantes de Medicina ao Teste de Progresso (TP) se dá de forma aleatória ou por alguma característica sistemática deles, o que poderia influenciar a representatividade dos resultados obtidos pelos participantes. Objetivo: Este estudo teve como objetivos comparar os índices de desempenho acadêmico, no curso de Medicina da UFSC, dos alunos presentes e ausentes ao TP em 2019; propor uma maneira de estimar, a partir desses índices, quais seriam as notas dos faltantes se tivessem participado do TP; e identificar fatores associados à ausência ao TP. Método: Foram comparadas as médias dos índices de desempenho acadêmico, globais e nas diferentes fases (semestres) dos grupos de alunos presentes e ausentes ao TP, utilizando teste t de Student para amostras independentes. Por meio de uma técnica de regressão linear, foram imputadas as prováveis notas no TP ao grupo de alunos ausentes. Resultado: As médias globais dos três indicadores acadêmicos foram significativamente menores nos alunos ausentes ao TP (p variando de < 0,03 a < 0,0001); em dez das 11 fases (semestres) analisadas do curso, os indicadores acadêmicos dos faltosos foram piores do que dos presentes. A imputação de notas no TP aos ausentes permitiu verificar que existe correlação (R = 0,62) entre a porcentagem destes e a diferença de notas entre os grupos que realizaram e os que faltaram ao TP. Entre os alunos do gênero masculino, 25,8% não fizeram o TP, enquanto no gênero feminino foram 16,6% (diferença com p < 0,01). Conclusão: A ausência de alunos ao TP não se dá de forma aleatória. Entre os faltosos, há uma tendência sistemática de existirem alunos com piores índices de desempenho acadêmico. O uso de imputação múltipla de dados evidencia uma correlação entre a porcentagem de faltosos e a diferença na média da nota no TP, desse grupo, comparada à média da nota dos participantes. A proporção de homens que faltaram ao TP foi significativamente maior do que a de mulheres.

Abstract: Introduction: It is not known whether the absence of medical students at the Progress Test (PT) is random event or if it due to some systematic characteristic of the students, which could influence the representativeness of the results obtained by the participants. Objectives: 1) to compare the academic performance indexes, in UFSC Medical School, of students who were present and absent from the PT in 2019; 2) to propose a way to estimate, based on these indexes, what the absentee's grades would be if they had participated in the PT; 3) to identify factors associated with absence from the PT. Method: The averages of academic performance indexes, overall and in the different phases (semesters) in the groups of students who were present and absent from the PT, were compared using Student's t test for independent samples. Using a linear regression technique, the probable PT scores were assigned to the group of absent students. Results: The global averages of the three academic indicators were significantly lower in students absent from the PT (p ranging from < 0.03 to < 0.0001); in 10 of the 11 analyzed course phases (semesters), the academic indicators of absentees were worse than those present at the test. The attribution of PT grades to the absentees allowed us to verify that there is a correlation (R=0.62) between the percentage of these students and the difference in grades between the groups that took and those that did not take the PT. Among male students, 25.8% did not attend the PT, while among female students the number of absentees was 16.6% (difference with p <0.01). Conclusions: The absence of students at the PT does not occur randomly. Among the absentees, there is a systematic tendency to have students with worse academic performance. The use of multiple imputation of data demonstrate a correlation between the percentage of absentees and the difference in the average of grades in the PT of this group, compared to the average of the participants' grades. The proportion of male students who missed the PT was significantly higher than that of female students.

Zika virus-induced brain malformations in chicken embryos.

BACKGROUND: Zika virus (ZIKV) was confirmed to be related to microcephaly in 2016. However, there is still a need for understanding the embryonic morphological changes induced by ZIKV and when they occur. Here, chicken embryos were chosen as experimental model of ZIKV to evaluate virus-associated morphological alterations that might take place during embryonic development. METHODS: A screening with different viral doses was conducted in embryos at HH Stage 10-12 (E1.5) as well as a follow up of the first 5 days postinfection (dpi) was performed to observe the main morphologic changes post ZIKV infection. RESULTS: ZIKV exposed embryos presented a higher prevalence of mortality and defects such as brain malformation when compared to controls. Moreover, we observed that the phenotypes become more evident at 4dpi, when the viral load quantification reaches a peak. CONCLUSIONS: We found that ZIKV exposed embryos presented a high prevalence of mortality and central nervous system (CNS) abnormalities in a dose-dependent manner. The phenotype was more evident 4 days postinfection, when the viral load quantification reached a peak.

Short-Term Alterations in Behavior and Astroglial Function After Intracerebroventricular Infusion of Methylglyoxal in Rats.

Methylglyoxal (MG) is a by-product of glycolysis. In pathological conditions, particularly diabetes mellitus, this molecule is unbalanced, causing widespread protein glycation. In addition to protein glycation, other effects resulting from high levels of MG in the central nervous system may involve the direct modulation of GABAergic and glutamatergic neurotransmission, with evidence suggesting that the effects of MG may be related to behavioral changes and glial dysfunction. In order to evaluate the direct influence of MG on behavioral and biochemical parameters, we used a high intracerebroventricular final concentration (3 µM/µL) to assess acute effects on memory and locomotor behavior in rats, as well as the underlying alterations in glutamatergic and astroglial parameters. MG induced, 12 h after injection, a decrease in locomotor activity in the Open field and anxiolytic effects in rats submitted to elevated plus-maze. Subsequently, 36 h after surgery, MG injection also induced cognitive impairment in both short and long-term memory, as evaluated by novel object recognition task, and in short-term spatial memory, as evaluated by the Y-maze test. In addition, hippocampal glutamate uptake decreased and glutamine synthetase activity and glutathione levels diminished during seventy-two hours after infusion of MG. Interestingly, the astrocytic protein, S100B, was increased in the cerebrospinal fluid, accompanied by decreased hippocampal S100B mRNA expression, without any change in protein content. Taken together, these results may improve our understanding of how this product of glucose metabolism can induce the brain dysfunction observed in diabetic patients, as well as in other neurodegenerative conditions, and further defines the role of astrocytes in disease and therapeutics.

The Brazilian-Portuguese version of the Sleep Hygiene Index (SHI): validity, reliability and association with depressive symptoms and sleep-related outcomes.

OBJECTIVE: To translate the Sleep Hygiene Index (SHI) to Brazilian Portuguese, to describe its psychometric properties and to show its association with sleep quality, daytime sleepiness, risk for sleep apnea and depressive symptoms. METHODS: Thirty subjects participated in the cultural adaptation and the item clarity evaluation. Twenty subjects answered the instrument in three different time-points for test-retest reliability. Eighty adult workers completed the SHI, the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale (ESS), the Beck Depression Inventory (BDI) and the STOP-BANG (S-B). RESULTS: SHI shows an acceptable internal consistency (Cronbach's α=0.75), as well as a high reproducibility (intraclass correlation=0.972, p<0.01). The three final factors of confirmatory factor analysis extract an average of 48.22% of the total sample variance. Worse sleep hygiene (higher SHI score) correlated with poor sleep quality (r=0.398, p<0.001), excessive daytime sleepiness (r=0.406, p<0.001) and depressive symptoms (r=0.324, p=0.003). No correlations with S-B were found. CONCLUSIONS: SHI presents satisfactory-to-optimal psychometric properties. This instrument is useful for treatment planning and management of sleep hygiene practices. Thus, it represents a reliable way of assessing sleep hygiene quantitatively in both research and clinical settings.

Neuroinflammation and Neuromodulation in Neurological Diseases.

Neuroimmunology is a relatively young science. This discipline has emerged today from the research field as a mature and fully developed innovative research area that integrates not only pure topics of neuroimmunology, but also expands on wider fields such as neuroplasticity, neuronal reserve and neuromodulation in association with clinical events, amongst which behavioral disorders stand out. The Cuban School of Neuroimmunology-a recent meeting that took place in Havana, Cuba-focused on topics based on the molecular mechanisms of neuroinflammation in neurological disorders involving behavioral manifestations, such as multiple sclerosis (MS), autism, cerebellar ataxias, Alzheimer´s disease and stroke among others, as well as on the use of new interventional technologies in neurology. Professor Luis Velazquez, from the Cuban Academy of Sciences, dictated an interesting lecture on Spinocerebellar ataxias, a genetic disorder where recent hypotheses related to the influence of neuroinflammation as a neurobiological factor influencing the progression of this disease have emerged. At the same time, the use of new interventional technologies in neurology was discussed, including those referring to novel disease modifying therapies in the course of MS and the use of transcranial magnetic stimulation in several neurological diseases, the latter reinforcing how interventional strategies in the form of non-invasive bran stimulation can contribute to physical rehabilitation in neurology. This paper summarizes the highlights of the most relevant topics presented during the First Cuban School of Neuroimmunology, organized by the Cuban Network of Neuroimmunology, held in June 2019.

Guanosine protects against Ca2+-induced mitochondrial dysfunction in rats.

Mitochondria play an important role in cell life and in the regulation of cell death. In addition, mitochondrial dysfunction contributes to a wide range of neuropathologies. The nucleoside Guanosine (GUO) is an endogenous molecule, presenting antioxidant properties, possibly due to its direct scavenging ability and/or from its capacity to activate the antioxidant defense system. GUO demonstrate a neuroprotective effect due to the modulation of the glutamatergic system and maintenance of the redox system. Thus, considering the few studies focused on the direct effects of GUO on mitochondrial bioenergetics, we designed a study to evaluate the in vitro effects of GUO on rat mitochondrial function, as well as against Ca2+-induced impairment. Our results indicate that GUO prevented mitochondrial dysfunction induced by Ca2+ misbalance, once GUO was able to reduce mitochondrial swelling in the presence of Ca2+, as well as ROS production and hydrogen peroxide levels, and to increase manganese superoxide dismutase activity, oxidative phosphorylation and tricarboxylic acid cycle activities. Our study indicates for the first time that GUO could direct prevent the mitochondrial damage induced by Ca2+ and that these effects were not related to its scavenging properties. Our data indicates that GUO could be included as a new pharmacological strategy for diseases linked to mitochondrial dysfunction.

Neuroprotective Effects of Guanosine Administration on In Vivo Cortical Focal Ischemia in Female and Male Wistar Rats.

Guanosine (GUO) has neuroprotective effects in experimental models of brain diseases involving glutamatergic excitotoxicity in male animals; however, its effects in female animals are poorly understood. Thus, we investigated the influence of gender and GUO treatment in adult male and female Wistar rats submitted to focal permanent cerebral ischemia in the motor cortex brain. Female rats were subdivided into non-estrogenic and estrogenic phase groups by estrous cycle verification. Immediately after surgeries, the ischemic animals were treated with GUO or a saline solution. Open field and elevated plus maze tasks were conducted with ischemic and naïve animals. Cylinder task, immunohistochemistry and infarct volume analyses were conducted only with ischemic animals. Female GUO groups achieved a full recovery of the forelimb symmetry at 28-35 days after the insult, while male GUO groups only partially recovered at 42 days, in the final evaluation. The ischemic insult affected long-term memory habituation to novelty only in female groups. Anxiety-like behavior, astrocyte morphology and infarct volume were not affected. Regardless the estrous cycle, the ischemic injury affected differently female and male animals. Thus, this study points that GUO is a potential neuroprotective compound in experimental stroke and that more studies, considering the estrous cycle, with both genders are recommended in future investigation concerning brain diseases.

Long-term effect of uncomplicated Plasmodium berghei ANKA malaria on memory and anxiety-like behaviour in C57BL/6 mice.

BACKGROUND: Cerebral malaria, the main complication of Plasmodium falciparum infection in humans, is associated with persistent neurocognitive sequels both in human disease and the murine experimental model. In recent years, cognitive deficits related to uncomplicated (non-cerebral) malaria have also been reported in chronically exposed residents of endemic areas, but not in some murine experimental models of non-cerebral malaria. This study aimed at evaluating the influence of uncomplicated malaria on different behavioural paradigms associated with memory and anxiety-like parameters in a murine model that has the ability to develop cerebral malaria. METHODS: Plasmodium berghei ANKA-infected and non-infected C57BL/6 mice were used. Development of cerebral malaria was prevented by chloroquine treatment starting on the fourth day of infection. The control group (non-infected mice) were treated with PBS. The effect of uncomplicated malaria infection on locomotor habituation, short and long-term memory and anxious-like behaviour was evaluated 64 days after parasite clearance in assays including open field, object recognition, Y-maze and light/dark tasks. RESULTS: Plasmodium berghei ANKA-infected mice showed significant long-lasting disturbances reflected by a long-term memory-related behaviour on open field and object recognition tasks, accompanied by an anxious-like phenotype availed on open field and light-dark tasks. CONCLUSIONS: Long-term neurocognitive sequels may follow an uncomplicated malaria episode in an experimental model prone to develop cerebral malaria, even if the infection is treated before the appearance of clinical signs of cerebral impairment.

α-Ketoadipic Acid and α-Aminoadipic Acid Cause Disturbance of Glutamatergic Neurotransmission and Induction of Oxidative Stress In Vitro in Brain of Adolescent Rats.

Tissue accumulation of α-ketoadipic (KAA) and α-aminoadipic (AAA) acids is the biochemical hallmark of α-ketoadipic aciduria. This inborn error of metabolism is currently considered a biochemical phenotype with uncertain clinical significance. Considering that KAA and AAA are structurally similar to α-ketoglutarate and glutamate, respectively, we investigated the in vitro effects of these compounds on glutamatergic neurotransmission in the brain of adolescent rats. Bioenergetics and redox homeostasis were also investigated because they represent fundamental systems for brain development and functioning. We first observed that AAA significantly decreased glutamate uptake, whereas glutamate dehydrogenase activity was markedly inhibited by KAA in a competitive fashion. In addition, AAA and more markedly KAA induced generation of reactive oxygen and nitrogen species (increase of 2',7'-dichloroflurescein (DCFH) oxidation and nitrite/nitrate levels), lipid peroxidation (increase of malondialdehyde concentrations), and protein oxidation (increase of carbonyl formation and decrease of sulfhydryl content), besides decreasing the antioxidant defenses (reduced glutathione (GSH)) and aconitase activity. Furthermore, KAA-induced lipid peroxidation and GSH decrease were prevented by the antioxidants α-tocopherol, melatonin, and resveratrol, suggesting the involvement of reactive species in these effects. Noteworthy, the classical inhibitor of NMDA glutamate receptors MK-801 was not able to prevent KAA-induced and AAA-induced oxidative stress, determined by DCFH oxidation and GSH levels, making unlikely a secondary induction of oxidative stress through overstimulation of glutamate receptors. In contrast, KAA and AAA did not significantly change brain bioenergetic parameters. We speculate that disturbance of glutamatergic neurotransmission and redox homeostasis by KAA and AAA may play a role in those cases of α-ketoadipic aciduria that display neurological symptoms.

Experimental evidence that overexpression of NR2B glutamate receptor subunit is associated with brain vacuolation in adult glutaryl-CoA dehydrogenase deficient mice: A potential role for glutamatergic-induced excitotoxicity in GA I neuropathology.

Glutaric aciduria type I (GA I) is biochemically characterized by accumulation of glutaric and 3-hydroxyglutaric acids in body fluids and tissues, particularly in the brain. Affected patients show progressive cortical leukoencephalopathy and chronic degeneration of the basal ganglia whose pathogenesis is still unclear. In the present work we investigated parameters of bioenergetics and redox homeostasis in various cerebral structures (cerebral cortex, striatum and hippocampus) and heart of adult wild type (Gcdh(+/+)) and glutaryl-CoA dehydrogenase deficient knockout (Gcdh(-/-)) mice fed a baseline chow. Oxidative stress parameters were also measured after acute lysine overload. Finally, mRNA expression of NMDA subunits and GLT1 transporter was determined in cerebral cortex and striatum of these animals fed a baseline or high lysine (4.7%) chow. No significant alterations of bioenergetics or redox status were observed in these mice. In contrast, mRNA expression of the NR2B glutamate receptor subunit and of the GLT1 glutamate transporter was higher in cerebral cortex of Gcdh(-/-) mice. Furthermore, NR2B expression was markedly elevated in striatum of Gcdh(-/-) animals receiving chronic Lys overload. These data indicate higher susceptibility of Gcdh(-/-) mice to excitotoxic damage, implying that this pathomechanism may contribute to the cortical and striatum alterations observed in GA I patients.

Planning future clinical trials in Machado Joseph disease: Lessons from a phase 2 trial.

BACKGROUND: In a recent phase 2 clinical trial in spinocerebellar ataxia type 3/Machado Joseph disease (SCA3/MJD), a neurogenetic disorder without specific therapy, benefits of lithium carbonate were found only on secondary efficacy outcomes, all related to ataxic features. In order to help designing future studies, we further analyzed the trial data searching for treatment response modifiers and metric properties of spinocerebellar ataxia (SCA) scales. METHODS: Efficacy analysis was performed with the Neurological Examination Score for the Assessment of Spinocerebellar Ataxia (NESSCA) and the Scale for the Assessment and Rating of Ataxia (SARA) subscores and with the subgroup of patients with independent gait according to the 8-meter walking-time (8MW). Interactions of clinical/molecular findings with treatment response, minimally important differences (MIDs), and sample size estimations for NESSCA, SARA, Spinocerebellar Ataxia Functional Index (SCAFI) and Composite Cerebellar Functional Score (CCFS) were evaluated. RESULTS: 62 SCA3/MJD patients had been randomly assigned (1:1) for the double-blind, placebo-controlled trial. While cerebellar NESSCA (range: 0-7 points) differed between groups 0.64 points (95% CI 0.23 to 1.05, p<0.001) over the whole 48weeks of study, favoring lithium, no effect was found on non-ataxia subscores. Among patients able to perform the 8MW on baseline, NESSCA (p=0.010) and SCAFI (p=0.015) differed between groups favoring lithium. Finally, estimated sample sizes for the scales were provided. CONCLUSION: Lithium efficacy on cerebellar NESSCA, and on SCAFI and CCFS in the primary analysis, together with the lack of effect on non-ataxia features suggests that lithium should be tested in phase 3 trials in SCA3/MJD and that ataxia scales should be preferred to multisystem neurological instruments as the primary outcome. The inclusion of early stage patients is advisable in future clinical trials in SCA3/MJD. TRIAL REGISTRATION: clinicaltrials.gov identifier: NCT01096082.

Changes in Brain 14-3-3 Proteins in Response to Insulin Resistance Induced by a High Palatable Diet.

The 14-3-3 protein family takes part in a wide range of cellular processes and is expressed in all eukaryotic organisms. In mammals, seven isoforms (ß, ε, η, γ, τ, ζ, and σ) have been identified. 14-3-3 proteins are suggested to modulate the insulin-signaling cascade in the brain. The aim of this study was to investigate whether insulin resistance state induced by high palatable diet modulates expression of the 14-3-3 proteins in brain. Wistar male rats (n = 8) were divided into two experimental groups: insulin resistant (IR), induced by high palatable diet, and control (CO) group. Biochemical parameters (glucose tolerance test and plasma lipid profile) were evaluated after 130 days. Brain structures (cortex and hippocampus) were dissected for evaluation of messenger RNA (mRNA) and protein levels of different 14-3-3 proteins. Statistical analyses included Student t test and Pearson correlation. Significant decrease was observed in Ywhah and in Ywahq mRNA levels in the cortex of IR group, while no changes were observed in the hippocampus. Significant increase of θ isoform was observed in hippocampus IR group by immunodetection, while no differences were detected in the remaining isoforms. Inverse correlation was observed between blood glucose levels in cortex IR group and both Ywhah and Ywhaq mRNA levels. Protein levels of Creb and phosphatidylinositide 3-kinases (PI3K) showed to be increased in the hippocampus. These alterations may be due to a compensatory effect of impaired insulin signaling. We demonstrated differential expression of 14-3-3 isoforms throughout brain regions of rats with IR. As a whole, our results indicate that brain 14-3-3 levels are influenced by different diets.

Disturbance of the glutamatergic system by glutaric acid in striatum and cerebral cortex of glutaryl-CoA dehydrogenase-deficient knockout mice: possible implications for the neuropathology of glutaric acidemia type I.

The role of excitotoxicity on the neuropathology of glutaric acidemia type I (GA I) is still under debate. Therefore, in the present work, we evaluated glutamate uptake by brain slices and glutamate binding to synaptic membranes, as well as glutamine synthetase activity in cerebral cortex and striatum from glutaryl-CoA dehydrogenase deficient (Gcdh(-/-)) mice along development (7, 15, 30 and 60 days of life) in the hopes of clarifying this matter. We also tested the influence of glutaric acid (GA) added exogenously on these parameters. [(3)H]Glutamate uptake was not significantly altered in cerebral cortex and striatum from Gcdh(-/-) mice, as compared to WT mice. However, GA provoked a significant decrease of [(3)H]glutamate uptake in striatum from both WT and Gcdh(-/-) mice older than 7 days. This inhibitory effect was more pronounced in Gcdh(-/-), as compared to WT mice. The use of a competitive inhibitor of glutamate astrocytic transporters indicated that the decrease of [(3)H]glutamate uptake caused by GA was due to the competition between this organic acid and glutamate for the same astrocytic transporter site. We also found that Na(+)-dependent [(3)H]glutamate binding (binding to transporters) was increased in the striatum from Gcdh(-/-) mice and that GA significantly diminished this binding both in striatum and cerebral cortex from Gcdh(-/-), but not from WT mice. Finally, we observed that glutamine synthetase activity was not changed in brain cortex and striatum from Gcdh(-/-) and WT mice and that GA was not able to alter this activity. It is therefore presumed that a disturbance of the glutamatergic neurotransmission system caused by GA may potentially be involved in the neuropathology of GA I, particularly in the striatum.

Pristanic acid provokes lipid, protein, and DNA oxidative damage and reduces the antioxidant defenses in cerebellum of young rats.

Zellweger syndrome (ZS) and some peroxisomal diseases are severe inherited disorders mainly characterized by neurological symptoms and cerebellum abnormalities, whose pathogenesis is poorly understood. Biochemically, these diseases are mainly characterized by accumulation of pristanic acid (Prist) and other fatty acids in the brain and other tissues. In this work, we evaluated the in vitro influence of Prist on redox homeostasis by measuring lipid, protein, and DNA damage, as well as the antioxidant defenses and the activities of aconitase and α-ketoglutarate dehydrogenase in cerebellum of 30-day-old rats. The effect of Prist on DNA damage was also evaluated in blood of these animals. Some parameters were also evaluated in cerebellum from neonatal rats and in cerebellum neuronal cultures. Prist significantly increased malondialdehyde (MDA) levels and carbonyl formation and reduced sulfhydryl content and glutathione (GSH) concentrations in cerebellum of young rats. It also caused DNA strand damage in cerebellum and induced a high micronuclei frequency in blood. On the other hand, this fatty acid significantly reduced α-ketoglutarate dehydrogenase and aconitase activities in rat cerebellum. We also verified that Prist-induced increase of MDA levels was totally prevented by melatonin and attenuated by α-tocopherol but not by the nitric oxide synthase inhibitor N(ω)-nitro-L-arginine methyl ester, indicating the involvement of reactive oxygen species in this effect. Cerebellum from neonate rats also showed marked alterations of redox homeostasis, including an increase of MDA levels and a decrease of sulfhydryl content and GSH concentrations elicited by Prist. Finally, Prist provoked an increase of dichlorofluorescein (DCFH) oxidation in cerebellum-cultivated neurons. Our present data indicate that Prist compromises redox homeostasis in rat cerebellum and blood and inhibits critical enzymes of the citric acid cycle that are susceptible to free radical attack. The present findings may contribute to clarify the pathogenesis of the cerebellar alterations observed in patients affected by ZS and some peroxisomal disorders in which Prist is accumulated.

Cellular senescence induced by prolonged subculture adversely affects glutamate uptake in C6 lineage.

Several researchers have recently used C6 cells to evaluate functional properties of high-affinity glutamate transporters. However, it has been demonstrated that this lineage suffers several morphological and biochemical alterations according to the number of passages in culture. Currently, there are no reports showing whether functional properties of high-affinity glutamate transporters comply with these sub culturing-dependent modifications. The present study aimed to compare the functional properties of high-affinity glutamate transporters expressed in early (EPC6) and late (LPC6) passage C6 cells through a detailed pharmacological and biochemical characterization. Between 60-180 min of L-[(3)H]glu incubation, LPC6 presented an intracellular [(3)H] 55% lower than EPC6. Both cultures showed a time-dependent increase of intracellular [(3)H] reaching maximal levels at 120 min. Cultures incubated with D-[(3)H]asp showed a time-dependent increase of [(3)H] until 180 min. Moreover, LPC6 have a D-[(3)H]asp-derived intracellular [(3)H] 30-45% lower than EPC6 until 120 min. Only EAAT3 was immunodetected in cultures and its total content was equal between them. PMA-stimulated EAAT3 trafficking to membrane increased 50% of L-[(3)H]glu-derived intracellular [(3)H] in EPC6 and had no effect in LPC6. LPC6 displayed characteristics that resemble senescence, such as high ß-Gal staining, cell enlargement and increase of large and regular nuclei. Our results demonstrated that LPC6 exhibited glutamate uptake impairment, which may have occurred due to its inability to mobilize EAAT3 to cell membrane. This profile might be related to senescent process observed in this culture. Our results suggest that LPC6 cells are an inappropriate glial cellular model to investigate the functional properties of high-affinity glutamate transporters.

Increased glutamate receptor and transporter expression in the cerebral cortex and striatum of gcdh-/- mice: possible implications for the neuropathology of glutaric acidemia type I.

We determined mRNA expression of the ionotropic glutamate receptors NMDA (NR1, NR2A and NR2B subunits), AMPA (GluR2 subunit) and kainate (GluR6 subunit), as well as of the glutamate transporters GLAST and GLT1 in cerebral cortex and striatum of wild type (WT) and glutaryl-CoA dehydrogenase deficient (Gchh-/-) mice aged 7, 30 and 60 days. The protein expression levels of some of these membrane proteins were also measured. Overexpression of NR2A and NR2B in striatum and of GluR2 and GluR6 in cerebral cortex was observed in 7-day-old Gcdh-/-. There was also an increase of mRNA expression of all NMDA subunits in cerebral cortex and of NR2A and NR2B in striatum of 30-day-old Gcdh-/- mice. At 60 days of life, all ionotropic receptors were overexpressed in cerebral cortex and striatum of Gcdh-/- mice. Higher expression of GLAST and GLT1 transporters was also verified in cerebral cortex and striatum of Gcdh-/- mice aged 30 and 60 days, whereas at 7 days of life GLAST was overexpressed only in striatum from this mutant mice. Furthermore, high lysine intake induced mRNA overexpression of NR2A, NR2B and GLAST transcripts in striatum, as well as of GluR2 and GluR6 in both striatum and cerebral cortex of Gcdh-/- mice. Finally, we found that the protein expression of NR2A, NR2B, GLT1 and GLAST were significantly greater in cerebral cortex of Gcdh-/- mice, whereas NR2B and GLT1 was similarly enhanced in striatum, implying that these transcripts were translated into their products. These results provide evidence that glutamate receptor and transporter expression is higher in Gcdh-/- mice and that these alterations may be involved in the pathophysiology of GA I and possibly explain, at least in part, the vulnerability of striatum and cerebral cortex to injury in patients affected by GA I.

A randomized, phase 2 clinical trial of lithium carbonate in Machado-Joseph disease.

BACKGROUND: Because lithium exerts neuroprotective effects in preclinical models of polyglutamine disorders, our objective was to assess the safety and efficacy of lithium carbonate (0.5-0.8 milliequivalents per liter) in patients with Machado-Joseph disease (spinocerebellar ataxia type 3 [MJD/SCA3]). METHODS: For this phase 2, single-center, double-blind, parallel, placebo-controlled trial (ClinicalTrials.gov identifier NCT01096082), 62 patients who had MJD/SCA3 with a disease duration ≤10 years and an independent gait were randomly assigned (1:1) to receive either lithium or placebo. RESULTS: After 24 weeks, 169 adverse events were reported, including 50.3% in the lithium group (P = 1.00; primary safety outcome). Sixty patients (31 in the placebo group and 29 in the lithium group) were analyzed for efficacy (intention-to-treat analysis). Mean progression between groups did not differ according to scores on the Neurological Examination Score for the Assessment of Spinocerebellar Ataxia (NESSCA) after 48 weeks (-0.35; 95% confidence interval, -1.7 to 1.0; primary efficacy outcome). The lithium group exhibited minor progression on the PATA speech-rate (P = 0.002), the nondominant Click Test (P = 0.023), the Spinocerebellar Ataxia Functional Index (P = 0.003), and the Composite Cerebellar Functional Score (P = 0.029). CONCLUSIONS: Lithium was safe and well tolerated, but it had no effect on progression when measured using the NESSCA in patients with MJD/SCA3. This slowdown in secondary outcomes deserves further clarification.

O uso do diário como dispositivo cartográfico na formação em Odontologia / Using the diary as device cartographic in graduation of Dentistry / El uso del diario como dispositivo cartográfico en la formación en Odontologia

A desnaturalização de práticas de ensino tradicionais e a subjetivação do cuidado na formação conectam a Odontologia às ciências humanas e sociais ao transversalizar o conhecimento pela problematização das políticas públicas. O potencial intervencionista do diário o torna importante ferramenta de pesquisa pelas narrativas de experiências. A escrita intensifica a cognição-inventiva ao dar visibilidade e enunciação a alguns pontos estratégicos de aprendizagem que produzem afetações nos encontros do cotidiano acadêmico. As releituras dos diários potencializam o ensino/aprendizagem pela análise de implicação dos estudantes e professores com a clínica, a sociedade e a produção de subjetividade da saúde como um bem comum. As narrativas enunciam o interesse dos estudantes de participar do trabalho nos serviços públicos de saúde, que utilizam comumente como usuários. A cartografia produz conhecimento ao conectar o ensino de graduação com a pós-graduação.

The denaturalization of traditional teaching practices and the production of health care subjectivity in dentistry training connect both to the social sciences and the humanities, traversing the knowledge by identifying problems regarding public policies. The potentially interventional diary makes it an important research tool due to its experience reports. The diary writing intensifies the inventive-cognition by visualizing and enunciating the learning strategic points, which produce affects in everyday meetings. The readings of the student’s diaries by the teacher  intensifies the  teaching/learning process by using implication analyses with the clinic, the society and the production of subjectivity health as a social common good. The narratives enunciate the students’ interest in participating in public health services both as collaborators and as users. Cartography produces knowledge while connecting the teaching of graduation with post graduation.

La desnaturalización de prácticas de enseñanza tradicionales y la subjetivación del cuidado en la formación vinculan la Odontología a las ciencias humanas y sociales al colocar de forma transversal el conocimiento por la problematización de las políticas públicas. El potencial intervencionista del diario lo convierte en importante herramienta de investigación por las narraciones de experiencia. La escritura intensifica la cognición inventiva al dar visibilidad y enunciado a algunos puntos estratégicos de aprendizaje que producen afectaciones en los encuentros del cotidiano académico. Las relecturas de los diarios potencian la enseñanza/aprendizaje por el análisis de implicación de los estudiantes y profesores con la clínica, la sociedad y la producción de subjetividad de la salud como un bien común. Las narrativas enuncian el interés de los estudiantes en participar del trabajo en los servicios públicos de salud que utilizan, por lo general como usuarios. La cartografía produce conocimiento al conectar la enseñanza de graduación con el postgrado.