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Remyelination refers to myelin regeneration, which reestablishes metabolic supports to axons. However, remyelination often fails in multiple sclerosis (MS), leading to chronic demyelination and axonal degeneration. Therefore, pharmacological approaches toward enhanced remyelination are highly demanded. Recently, deferiprone (DFP) was reported to exert neuroprotective effects, besides its iron-chelating ability. Since DFP exerts protective effects through various mechanisms, which share several factors with myelin formation process, we aimed to investigate the effects of DFP treatment on remyelination. Focal demyelination was induced by injection of lysolecithin, into the optic nerve of male C57BL/6J mice. The animals were treated with DFP/vehicle, starting from day 7 and continued during the myelin repair period. Histopathological, electrophysiological, and behavioral studies were used to evaluate the outcomes. Results showed that DFP treatment enhanced remyelination, decreased g-ratio and increased myelin thickness. At the mechanistic level, DFP enhanced oligodendrogenesis and ameliorated gliosis during the remyelination period. Furthermore, our results indicated that enhanced remyelination led to functional recovery as evaluated by the electrophysiological and behavioral tests. Even though the exact molecular mechanisms by which DFP-enhanced myelin repair remain to be elucidated, these results raise the possibility of using deferiprone as a therapeutic agent for remyelination therapy in MS.
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INTRODUCTION: A healthy daily diet and consuming certain nutrients, such as polyphenols, vitamins, and unsaturated fatty acids, may help neuronal health maintenance. Polyphenolic chemicals, which have antioxidant and anti-inflammatory properties, are involved in the neuroprotective pathway. Because of their nutritional value, nuts have been shown in recent research to be helpful in neuroprotection. OBJECTIVE: Hazelnut is often consumed worldwide in various items, including processed foods, particularly in bakery, chocolate, and confectionery products. This nut is an excellent source of vitamins, amino acids, tocopherols, phytosterols, polyphenols, minerals, and unsaturated fatty acids. Consuming hazelnut may attenuate the risk of neurodegenerative disorders including Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, multiple sclerosis, and Huntington's disease due to its anti-inflammatory and anti-oxidant qualities. RESULTS: Many documents introduce hazelnut as an excellent choice to provide neuroprotection against neurodegenerative disorders and there is some direct proof of its neuroprotective effects. DISCUSSION: So hazelnut consumption in daily diet may reduce neurodegenerative disease risk and be advantageous in reducing the imposed costs of dealing with neurodegenerative diseases.
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Encéfalo , Corylus , Doenças Neurodegenerativas , Humanos , Doenças Neurodegenerativas/prevenção & controle , Nozes , Antioxidantes/administração & dosagem , Fármacos Neuroprotetores/administração & dosagem , Animais , Dieta , Valor NutritivoRESUMO
Multiple sclerosis (MS) is a primary inflammatory demyelinating disease with different clinical courses and subtypes. The present study aimed to determine whether mitochondrial dysfunction and sirtuins 1 and 3, as metabolism and epigenetic modifying factors, might contribute to MS disease progression measured by physical disability and cognitive impairment.The volunteers (n = 20 controls, n = 59 MS) were recruited and assessed for cognitive function and disability scores; then, patients were clinically classified as relapsing-remitting (RR) in remission phase, RR in relapse phase, and secondary progressive MS. We measured sirtuin (SIRT) 1 and 3 levels, mitochondrial complex I, IV, aconitase, and α-ketoglutarate dehydrogenase (α-KGD) activity in the peripheral blood mononuclear cells (PBMCs). Furthermore, SIRT1, pyruvate, lactate, and cytochrome c (Cyt c) were determined in plasma. Finally, we performed postmortem tissue immunohistochemistry to assess the level of SIRT1 and SIRT3 in the brain lesions of patients with MS.Increased disability and cognitive impairment in patients were correlated. Plasma level of lactate showed a correlation with the disability in MS patients; moreover, a trend toward increased Cyt c plasma level was observed. Investigation of PBMCs exhibited decreased SIRT1 during the relapse phase along with a reduced complex IV activity in all MS subgroups. α-KGD activity was significantly increased in the RR-remission, and SIRT3 was elevated in RR-relapse group. This elevation correlated with disability and cognitive impairment. Finally, immunohistochemistry demonstrated increased levels of SIRT1 and 3 in the brain active lesion of patients with MS.Our data suggest that mitochondrial dysfunction and alteration in some epigenetics and metabolism modifying factors in the CNS and peripheral blood cells may contribute or correlate with MS progression.
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We aimed to study how morphine affects synaptic transmission in the dentate gyrus and CA1 regions along the hippocampal long axis. For this, recording and measuring of field excitatory postsynaptic potentials (fEPSPs) were utilized to test the effects of repeated morphine exposure on paired-pulse evoked responses and long-term potentiation (LTP) at Schaffer collateral-CA1 (Sch-CA1), temporoammonic-CA1 (TA-CA1) and perforant pathway-dentate gyrus (PP-DG) synapses in transverse slices from the dorsal (DH), intermediate (IH), and ventral (VH) hippocampus in adult male rats. After repeated morphine exposure, the expression of opioid receptors and the α1 and α5 GABAA subunits were also examined. We found that repeated morphine exposure blunt the difference between the DH and the VH in their basal levels of synaptic transmission at Sch-CA1 synapses that were seen in the control groups. Significant paired-pulse facilitation of excitatory synaptic transmission was observed at Sch-CA1 synapses in slices taken from all three hippocampal segments as well as at PP-DG synapses in slices taken from the VH segment in the morphine-treated groups as compared to the control groups. Interestingly, significant paired-pulse inhibition of excitatory synaptic transmission was observed at TA-CA1 synapses in the DH slices from the morphine-treated group as compared to the control group. While primed-burst stimulation (a protocol reflecting normal neuronal firing) induced a robust LTP in hippocampal subfields in all control groups, resulting in a decaying LTP at TA-CA1 synapses in the VH slices and at PP-DG synapses in both the IH and VH slices taken from the morphine-treated rats. In the DH of morphine-treated rats, we found increased levels of the mRNAs encoding the α1 and α5 GABAA subunits as compared to the control group. Taken together, these findings suggest the potential mechanisms through which repeated morphine exposure causes differential changes in circuit excitability and synaptic plasticity in the dentate gyrus and CA1 regions along the hippocampal long axis.
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Morfina , Via Perfurante , Masculino , Ratos , Animais , Morfina/farmacologia , Colaterais de Schaffer , Ratos Wistar , Hipocampo/fisiologia , Plasticidade Neuronal , Potenciação de Longa Duração/fisiologia , Sinapses/fisiologia , Giro Denteado , Ácido gama-Aminobutírico/metabolismoRESUMO
Background: Based on evidence there are accepted links among early nutrition, epigenetic processes, and cognitive performance. Almond as a nutritious food could exert neuroprotective effects and improve anxiety, learning, and memory.Methods: In the current study, female rats were fed with a diet containing 5% (w/w) almonds during the mating period (two days) and gestation period (21 consecutive days). Then, the effect of the almond diet on short-term memory (Y maze), anxiety (elevated plus maze), and stress adaptation (forced swimming test) were investigated in the adult male offspring. The hippocampus (HIP), prefrontal cortex (PFC), and amygdala (AMY) of offspring were collected, and the level of cyclic AMP response element-binding proteins (CREB), brain-derived neurotrophic factor (BDNF) was assessed by western blotting. Also, Monoamine oxidases (MAO)-A and B activity were evaluated via enzymatic assays.Results: Our results indicated that prenatal almond consumption improved memory, made a modest reduction in anxiety-like behavior, and increased stress adaptation in adult male offspring. Also, molecular assessments showed an increased level of CREB phosphorylation and BDNF in the HIP and PFC of the almond group, while the activity of MAO-A and MAO-B was inhibited by almond consumption in mentioned areas.Discussion: These findings introduce almonds as a beneficial diet during pregnancy, for improving short-term memory, stress adaptation, and cognitive performance in adult offspring.
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Efeitos Tardios da Exposição Pré-Natal , Prunus dulcis , Gravidez , Ratos , Masculino , Feminino , Animais , Humanos , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Prunus dulcis/metabolismo , Aprendizagem em Labirinto , Memória de Curto Prazo , Hipocampo/metabolismo , Cognição , Efeitos Tardios da Exposição Pré-Natal/psicologiaRESUMO
Multiple sclerosis (MS) is a chronic inflammatory disease, which leads to focal demyelination in the brain and spinal cord. Studies showed that iron released during the course of myelin breakdown exacerbates tissue damage, which is in agreement with the features of iron-dependent cell death, ferroptosis. Here, we aimed to investigate the possible contribution of ferroptosis in the demyelinated optic nerve, and to explore the effectiveness of ferroptosis inhibitor, deferiprone (DFP), on the extent of demyelination, inflammation and axonal damage. For this purpose, focal demyelination was induced by injection of lysolecithin (LPC), into the optic nerve of male C57BL/6J mice. Afterward, optic nerves were harvested at different time points from as early as 6 h up to 7 days post-LPC injection. Next, to evaluate the effectiveness of DFP two groups of animals received daily intraperitoneal injection of DFP for 3 or 7 continuous days. Vehicle groups received saline. Iron deposition was observed at different time points post-LPC injection from 6 h to 7 days post injection. Examining ferroptosis markers showed a significant reduction in glutathione content along with increased level of malondialdehyde and upregulated ferroptosis marker genes at early time points after injection. Besides, DFP treatment during the inflammatory phase of the model resulted in decreased microgliosis and inflammation. Reduced demyelination, microgliosis and astrogliosis was shown in mice that received DFP for 7 days. Moreover, DFP protected against axonal damage and retinal ganglion cells loss. Our results suggest the possible contribution of ferroptosis pathway in the process of demyelination. The therapeutic strategies targeting iron deposition, e.g. DFP treatment might thus represent a promising therapeutic target for patients with MS.
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Ferroptose , Esclerose Múltipla , Animais , Masculino , Camundongos , Deferiprona/farmacologia , Inflamação , Ferro/metabolismo , Camundongos Endogâmicos C57BL , Bainha de Mielina/metabolismo , Neuroproteção , Nervo Óptico/metabolismoRESUMO
In the last decade, there has been a great increase in methamphetamine hydrochloride (METH) abuse by pregnant women that exposes fetus and human offspring to a wide variety of developmental impairments that may be the underlying causes of future psychosocial issues. Herein, we investigated whether prenatal METH exposure with different doses (2 and 5 mg/kg) could influence neuronal cell death and antioxidant level in the different brain regions of adult male and female offspring. Adult male and female Wistar rats prenatally exposed to METH (2 or 5 mg/kg) and/or saline was used in this study. At week 12, adult rats' offspring were decapitated to collect different brain region tissues including amygdala (AMY) and prefrontal cortices (PFC). Western blot analysis was performed to evaluate the apoptosis- and autophagy-related markers, and enzymatic assay was used to measure the level of catalase and also reduced glutathione (GSH). Our results showed that METH exposure during pregnancy increased the level of apoptosis (BAX/Bcl-2 and Caspase-3) and autophagy (Beclin-1 and LC3II/LC3I) in the PFC and AMY areas of both male and female offspring's brain. Also, we found an elevation in the GSH content of all both mentioned brain areas and catalase activity of PFC in the offspring's brain. These changes were more significant in female offspring. Being prenatally exposed to METH increased cell death at least partly via apoptosis and autophagy in AMY and PFC of male and female offspring's brain, while the antioxidant system tried to protect cells in these regions.
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Metanfetamina , Gravidez , Animais , Feminino , Ratos , Masculino , Humanos , Metanfetamina/toxicidade , Ratos Wistar , Córtex Pré-Frontal , Morte Celular , Transdução de SinaisRESUMO
Abstract Studies have revealed beneficial role of vitamin D3 in neuro-cognitive function. There is also supporting evidence on the involvement of nitric oxide (NO) in the neuro-protective action. However, its over production could contribute to brain disorders. In this study, demyelination was induced by ethidium bromide (EB) injection into the right side of the hippocampus area of male rats. Vitamin D3 was administered to rats for 7 and 28 days prior to behavioral experiments using Morris water maze (MWM). Travelled distance, time spent to reach the platform, and time spent in target zone, were considered for learning and spatial memory evaluation. Nitrite oxide (NO2-) concentration was measured as an indicator for nitric oxide production. The time spent to reach the platform and the travelled distance were decreased significantly by 28 days of vitamin D3 administration (compared to 7 days experiment). Time spent in target quadrant was significantly lowered by administered vitamin on day 28. Therefore, considering a number of studies that have shown the effect of vitamin D3 on cognition, these findings could support their potential effect. Besides, nitric oxide concentration significantly differed in 28 days of vitamin D3 treated group compared with the groups treated with EB or 7 days of vitamin D3.
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Colecalciferol/análise , Óxido Nítrico/efeitos adversos , Encefalopatias/patologia , Doenças Desmielinizantes/classificação , Etídio/efeitos adversos , Memória Espacial/classificação , Teste do Labirinto Aquático de MorrisRESUMO
BACKGROUND: É£-aminobutyric acid (GABA) facilitator valproic acid may be able to curb memory disruption induced by morphine exposure. OBJECTIVE: The effects of the GABA facilitator valproic acid on the behavioral tolerance induced by morphine were investigated. Then hippocampal-dependent tasks named spatial-working and short-term memory procedures using the Y-maze apparatus were examined in morphine tolerant rats. Finally, the changes in the expression of hippocampal GABA-A receptors underlying morphine tolerance were also examined. METHODS: Rats were treated with daily morphine injections, with or without distinct contextual pairing. To examine the effect of valproic acid on morphine tolerance expression, valproic acid was pretreated an hour before morphine. Spatial-working and short-term memory procedures using the Y-maze apparatus were examined in morphine tolerant rats. Afterwards the changes in the expression of hippocampal GABAα receptors using the quantitative real-time PCR and western blot techniques to detect GABArα subunits mRNAs and protein level were studied. RESULTS: Our results showed that both learned and non-associative morphine tolerance influence short-term memory and the subjacent expression of GABArα mRNAs and protein level. Despite its attenuating effects on the development and expression of both learned and non-associative morphine tolerance, only associative morphine tolerance-induced memory dysfunction was ameliorated by valproic acid pretreatment. We also found that the expression of GABArα1, α2, α5 subunits mRNAs and GABAα protein level were affected heavier in associative morphine tolerant rats. CONCLUSION: Our data supports the hypothesis that unconditioned and learned morphine tolerance influences short-term memory and the expression of GABArα 1, α2, α5 mRNAs and GABArα protein level differently, and adds to our understanding of the behavioral and molecular aspects of the learned tolerance to morphine effects.
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Tolerância a Medicamentos , Regulação da Expressão Gênica/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Memória de Curto Prazo/efeitos dos fármacos , Morfina/farmacologia , Receptores de GABA-A/metabolismo , Ácido gama-Aminobutírico/metabolismo , Analgésicos Opioides/farmacologia , Animais , Hipocampo/metabolismo , Masculino , Aprendizagem em Labirinto , Ratos , Ratos Wistar , Receptores de GABA-A/genéticaRESUMO
Evidence has validated the prophylactic effects of exercising on different aspects of health. On the opposite side, immobilization may lead to various destructive effects causing neurodegeneration. Here, we investigated the association between exercising and mitochondrial quality for preventing the destructive effects of restraint stress in different rat brain regions. Twenty-four male Wistar rats, were randomized into four groups (n = 6), exercise, stress, exercise + stress, and control. The exercise procedure consisted of running on a rodent treadmill for 8 weeks, and rats in the stress group were immobilized for 6 h. Rats were then euthanized by decapitation and tricarboxylic acid (TCA) cycle enzyme activity, antioxidant levels, and mitochondrial biogenesis factors were assessed in the frontal, hippocampus, parietal and temporal regions using spectrophotometer and western blot technique. Based on our results, increased activity of TCA cycle enzymes in the exercised and exercise-stressed groups was detected, except for malate dehydrogenase which was decreased in exercise-stressed group, and fumarase that did not change. Furthermore, the level of antioxidant agents (superoxide dismutase and reduced glutathione), mitochondrial biogenesis factors (peroxisome proliferator-activated receptor gamma coactivator 1-alpha and mitochondrial transcription factor A), and dynamics markers (Mitofusin 2, dynamic related protein 1, PTEN induced putative kinase-1, and parkin) increased in both mentioned groups. Interestingly our results also revealed that the majority of the mitochondrial factors increased in the frontal and parietal lobes, which may be in relation with the location of motor and sensory areas. Exercise can be used as a prophylactic approach against bioenergetics and mitochondrial dysfunction.
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Encéfalo/metabolismo , Metabolismo Energético , Dinâmica Mitocondrial , Condicionamento Físico Animal , Restrição Física , Estresse Psicológico/metabolismo , Animais , Antioxidantes/metabolismo , Encéfalo/enzimologia , Encéfalo/patologia , Ciclo do Ácido Cítrico , Masculino , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Complexo Piruvato Desidrogenase/metabolismo , Ratos WistarRESUMO
BACKGROUND: Neuromyelitis Optica (NMO) is an inflammatory demyelinating disease that mainly affects optic nerves and spinal cord. Besides, loss of motor and cognitive function has been reported as important symptoms of disease. OBJECTIVE: Here we investigated the mitochondrial dysfunction and metabolic alterations in NMO patients and evaluate their correlation with disease progress, disability and cognitive impairment. METHODS: The individuals (12 controls and 12 NMO) were assessed for disease severity by expanded disease status scale (EDSS), cognitive function via symbol digit modalities test (SDMT) and fine motor disability by 9-hole peg test (9-HPT). We have measured Sirtuin 1 (SIRT1), SIRT3, mitochondrial complex I, complex IV, aconitase and α-ketoglutarate dehydrogenase (α-KGD) activity in peripheral blood mononuclear cells (PBMCs). Furthermore, SIRT1, pyruvate, lactate and cytochrome c (Cyt c) were determined in plasma. RESULTS: Our results exhibited increased 9-HPT time in NMO patients. 9-HPT results correlated with EDSS; and SDMT negatively correlated with disease duration and number of attacks in patients. Investigation of PBMCs of NMO patients exhibited a decrease of mitochondrial complex I and IV activity that was significant for complex IV. Besides, complex I activity was negatively correlated with 9-HPT time in NMO group. In the plasma samples, a correlation between pyruvate to lactate ratio and EDSS in NMO patients was found and a negative correlation between Cyt c concentration and SDMT was detected. CONCLUSION: Our data support the hypothesis that mitochondrial dysfunction occurred in the CNS and the peripheral blood may contribute to disease progress, disability level and the cognitive impairment in NMO patients.
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Transtornos Cognitivos/etiologia , Mitocôndrias/metabolismo , Neuromielite Óptica/patologia , Adulto , Estudos de Casos e Controles , Transtornos Cognitivos/diagnóstico , Citocromos c/metabolismo , Complexo I de Transporte de Elétrons/metabolismo , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Feminino , Humanos , Ácido Láctico/sangue , Leucócitos Mononucleares/metabolismo , Masculino , Pessoa de Meia-Idade , Neuromielite Óptica/complicações , Neuromielite Óptica/metabolismo , Ácido Pirúvico/sangue , Índice de Gravidade de Doença , Sirtuína 1/metabolismo , Sirtuína 3/metabolismoRESUMO
Multiple Sclerosis (MS) is a challenging and disabling condition particularly in the secondary progressive (SP) phase of this disease. The available treatments cannot ameliorate or stop disease progression in this phase, and there is an urgent need to focus on effective therapies and the molecular pathways involved SPMS. Given the significant impact of neurodegeneration, autoimmunity and metabolic alterations in MS, focusing on the molecules that target these different pathways could help in finding new treatments. Sirtuins (SIRTs) are NAD+ dependent epigenetic and metabolic regulators, which have critical roles in the physiology of central nervous system, immune system and metabolism. Based on these facts, SIRTs are crucial candidates of therapeutic targets in MS and collecting the information related to MS disease for each SIRT individually is noteworthy and highlights the lack of investigation in each part. In this review we summarized the role of different sirtuins as key regulator in neurodegeneration, autoimmunity and metabolism pathways. We also clarify the rationale behind selecting SIRTs as therapeutic targets in MS disease by collecting the researches showing alteration of these proteins in human samples of MS patients and animal model of MS, and also the improvement of modeled animals after SIRT-directed treatments.
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Autoimunidade/fisiologia , Esclerose Múltipla/metabolismo , Degeneração Neural/metabolismo , Sirtuínas/metabolismo , Animais , Sistema Nervoso Central/metabolismo , HumanosRESUMO
Growing evidence sheds light on the use of flavonoids as the promising alternatives for the treatment of chronic conditions, including cancer and neurodegenerative disorders. Accordingly, in the present study, we aimed at evaluating the effects of oral intake of two structurally different flavonoids 5-hydroxy-6,7,4'-trimethoxyflavone (flavone 1) and 5,7,4'-trihydroxyflavone (flavone 2) on recognition memory, hippocampal protein level of immediate early gene cFos and mitochondrial dynamic markers in Amyloid ß (Aß)-injected rats. Recognition aspect of memory and level of proteins were measured using novel object recognition test and Western blot, respectively. Our data indicated that even though flavone 1 was more effective than flavone 2 to prevent memory impairment, feeding with both flavones alleviated memory in Aß-injected rats. Furthermore, in flavones-administered rats, mitochondrial dynamic balancing returned to the control level by the decline in Dynamin-related protein-1 protein level, a known marker for mitochondrial fission, and elevation in protein level of mitochondrial fusion factors Mitofusins 1 and 2. In parallel with behavior results, flavone 1 was more effectual on mitochondrial dynamic moderating. The more neuroprotective effects of flavone 1 could be attributed to its methylated structure leading to crossing of the blood-brain barrier with ease and metabolic stability and bioactivity.
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Peptídeos beta-Amiloides/administração & dosagem , Flavonas/administração & dosagem , Hipocampo/efeitos dos fármacos , Dinâmica Mitocondrial/efeitos dos fármacos , Fármacos Neuroprotetores/administração & dosagem , Fragmentos de Peptídeos/administração & dosagem , Reconhecimento Psicológico/efeitos dos fármacos , Administração Oral , Animais , Hipocampo/metabolismo , Masculino , Proteínas Proto-Oncogênicas c-fos/metabolismo , Ratos WistarRESUMO
Several pathways involved in regulation of intracellular protein integrity are known as the protein quality control (PQC) system. Molecular chaperones as the main players are engaged in various aspects of PQC system. According to the importance of these proteins in cell survival, in the present study, we traced endoplasmic reticulum-specific markers and chaperone-mediated autophagy (CMA)-associated factors as two main arms of PQC system in intra-hippocampal amyloid beta (Aß)-injected rats during 10 days running. Data analysis from Western blot indicated that exposure to Aß activates immunoglobulin heavy-chain-binding protein (Bip) which is the upstream regulator of unfolded protein responses (UPR). Activation of UPR system eventually led to induction of pro-apoptotic factors like CHOP, calpain, and caspase-12. Moreover, our data revealed that protein disulfide isomerase activity dramatically decreased after Aß injection, which could be attributed to the increased levels of nitric oxide. Besides, Aß injection induced levels of 2 members of heat shock proteins (Hsp) 70 and 90. Elevated levels of Hsps family members are accompanied by increased levels of lysosome-associated membrane protein type-2A (Lamp-2A) that are involved in CMA. Despite the reduction in CHOP, calpain, caspase-12, and Lamp-2A protein levels, the levels of molecular chaperones Bip, Hsps70, and 90 increased 10 days after Aß injection in comparison to the control group. Based on our results, 10 days after Aß injection, despite the activation of protective chaperones, markers associated with neurotoxicity were still elevated.
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Peptídeos beta-Amiloides/metabolismo , Hipocampo/metabolismo , Óxido Nítrico/metabolismo , Isomerases de Dissulfetos de Proteínas/metabolismo , Desdobramento de Proteína , Animais , Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Retículo Endoplasmático/metabolismo , Masculino , Ligação Proteica/fisiologia , Ratos WistarRESUMO
In spite of characterizing the role of protein kinase A (PKA) in activating biochemical mechanisms, few studies have investigated the effects of PKA inhibitors on memory functions. In the present study, we used Pavlovian fear conditioning paradigm to evaluate memory alterations caused by two doses of H89 (as a conditional inhibitor of PKA) alone and in combination with amyloid-ß (Aß) in rats. Moreover, we used the Western blotting method to investigate the alterations in markers of transcription, oxidative stress, inflammation, and apoptosis pathways involved in memory impairment. Stereotaxic surgery was done to inject Aß (30 ng/side) directly into the hippocampal CA1 area bilaterally and H89 (5 or 10 µM) intracerebroventricular unilaterally. One series of rats were trained 7 days after injections, then contextual and tone tests were conducted on days 8 and 9, respectively. Second series of rats were trained 14 days after the injections and tests were carried out on days 15 and 16. Our behavioral results showed that H89 (5 µM) not only has no destructive effect on memory, but also attenuates memory deficit caused by Aß in combination groups. In contrast, H89 (10µM) has a reversible destructive effect on memory. Our molecular findings indicated that low dose of H89 increases CREB phosphorylation, Nrf2 and HO-1 which results in survival resistance to the stress. On the contrary, H89 with higher concentration leads to substantial increase of NF-κB and caspase-3 levels, which impair memory functions. In conclusion, our data suggest that H89 as a PKA inhibitor influences memory process through a dose and time dependent manner.
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Peptídeos beta-Amiloides/toxicidade , Condicionamento Clássico/efeitos dos fármacos , Proteínas Quinases Dependentes de AMP Cíclico/antagonistas & inibidores , Isoquinolinas/uso terapêutico , Transtornos da Memória/induzido quimicamente , Sulfonamidas/uso terapêutico , Animais , Proteína de Ligação a CREB/metabolismo , Caspase 3/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Medo , Reação de Congelamento Cataléptica/efeitos dos fármacos , Heme Oxigenase-1/metabolismo , Masculino , Transtornos da Memória/tratamento farmacológico , Fator 2 Relacionado a NF-E2/metabolismo , Ratos , Ratos Wistar , Fatores de TempoRESUMO
In the present study, the neuroprotective effect of 5-hydroxy-6,7,4'-trimethoxyflavone (flavone 1), a natural flavone, was investigated in comparison with another flavone, 5,7,4'-trihydroxyflavone (flavone 2) on the hippocampus of amyloid beta (Aß)-injected rats. Rats were treated with the 2 flavones (1 mg/kg/d) for 1 week before Aß injection. Seven days after Aß administration, memory function of rats was assessed in a passive avoidance test (PAT). Changes in the levels of mitochondrial transcription factor A (TFAM), peroxisome proliferator-activated receptor γ coactivator 1 α (PGC-1α), phospho-adenosine monophosphate (AMP)-activated protein kinase (pAMPK), AMPK, phospho-cAMP-responsive element-binding protein (CREB), CREB, and nuclear respiratory factor 1 (NRF-1) proteins were determined by Western blot analysis. Our results showed an improvement in memory in rats pretreated with flavonoids. At the molecular level, phosphorylation of CREB, known as the master modulator of memory processes, increased. On the other hand, the level of mitochondrial biogenesis factors, PGC-1α and its downstream molecules NRF-1 and TFAM significantly increased by dietary administration of 2 flavones. In addition, flavone 1 and flavone 2 prevented mitochondrial swelling and mitochondrial membrane potential reduction. Our results provided evidence that flavone 1 is more effective than flavone 2 presumably due to its O-methylated groups. In conclusion, it seems that in addition to classical antioxidant effect, flavones exert part of their protective effects through mitochondrial biogenesis.
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Doença de Alzheimer/prevenção & controle , Suplementos Nutricionais , Modelos Animais de Doenças , Flavonas/uso terapêutico , Fármacos Neuroprotetores/uso terapêutico , Nootrópicos/uso terapêutico , Fatores de Transcrição/agonistas , Doença de Alzheimer/metabolismo , Animais , Aprendizagem da Esquiva , Comportamento Animal , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/agonistas , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Hipocampo/metabolismo , Masculino , Memória , Dinâmica Mitocondrial , Proteínas Mitocondriais/agonistas , Proteínas Mitocondriais/metabolismo , Proteínas do Tecido Nervoso/agonistas , Proteínas do Tecido Nervoso/metabolismo , Neurônios/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Fosforilação , Processamento de Proteína Pós-Traducional , Ratos Wistar , Fatores de Transcrição/metabolismoRESUMO
The effects of mobile phone frequency electromagnetic field (RF-EMF, 940 MHz) on a stable cell line (HEK293T) harbouring the firefly luciferase gene were evaluated. A waveguide exposure system with 1 W input power provided the mean specific absorption rate of ≈0.09 W kg(-1) in 35 mm Petri dishes. The effects of exposure duration (15, 30, 45, 60 and 90 min) on luciferase activity and oxidative response elements were investigated. Endogenous luciferase activity was reduced after 30 and 45 min of continuous exposure, while after 60 min, the exposed cell lysate showed higher luciferase activity compared with the non-exposed control. Reactive oxygen species (ROS) generation was highest in the 30 min exposed cells as studied by 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescence. The observed boost in ROS was then followed by a sharp rise in catalase (CAT) and superoxide dismutase (SOD) activity and elevation of glutathione (GSH) during the 45 min exposure. Decrease in lipid peroxidation (malondialdehyde, MDA) was meaningful for the 45 and 60 min exposed cells. Therefore, it appears that an increase in the activity of luciferase after 60 min of continuous exposure could be associated with a decrease in ROS level caused by activation of the oxidative response. This ability in cells to overcome oxidative stress and compensate the luciferase activity could also be responsible for the adaptive response mechanism detected in ionizing radiation studies with RF-EMF pre-treatments.
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Campos Eletromagnéticos , Luciferases de Vaga-Lume/metabolismo , Catalase/metabolismo , Fluoresceínas/química , Vetores Genéticos/genética , Vetores Genéticos/metabolismo , Glutationa/metabolismo , Células HEK293 , Humanos , Luciferases de Vaga-Lume/genética , Estresse Oxidativo/efeitos da radiação , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo , Fatores de TempoRESUMO
OBJECTIVES: We evaluated the acetylcholinesterase (AChE) inhibitory and potential antioxidant effects of Salvia sahendica extract to investigate whether these molecules are involved in learning and memory improvement in rats injected with fibrillar amyloid beta (Aß) peptide in the CA1 region of their hippocampus. METHODS: Rats were fed with S. sahendica (100 mg/kg/day) for 1 week before Aß injection. Western blot analysis and enzymatic assays were carried out 7 days after injections. KEY FINDINGS: Our results indicated that S. sahendica extract decreased AChE activity. Besides, S. sahendica prevented reduction in the level of nuclear respiratory factor-1 and mitochondrial transcription factor A (TFAM). Our data indicated the lack of sensitivity in citrate synthase and reduction in the activity of malate dehydrogenase in the presence of Aß that was prevented with S. sahendica consumption. Pretreatment with S. sahendica extract impeded reduction of glutathione redox ratio, catalase and superoxide dismutase activity, while decreased the malondialdehyde level. CONCLUSIONS: Based on the importance of AChE activity inhibition and increased TFAM level in the prevention of cognitive impairment, the use of S. sahendica could open a new protective issue in therapeutic fields of neurodegenerative disease.