RESUMO
Background: Several different mechanisms have been proposed to explain long-term cognitive impairment in sepsis survivors. The role of persisting mitochondrial dysfunction is not known. We thus sought to determine whether stimulation of mitochondrial dynamics improves mitochondrial function and long-term cognitive impairment in an experimental model of sepsis.Methods: Sepsis was induced in adult Wistar rats by cecal ligation and perforation (CLP). Animals received intracerebroventricular injections of either rosiglitazone (biogenesis activator), rilmenidine, rapamycin (autophagy activators), or n-saline (sham control) once a day on days 7-9 after the septic insult. Cognitive impairment was assessed by inhibitory avoidance and object recognition tests. Animals were killed 24 h, 3 and 10 days after sepsis with the hippocampus and prefrontal cortex removed to determine mitochondrial function.Results: Sepsis was associated with both acute (24 h) and late (10 days) brain mitochondrial dysfunction. Markers of mitochondrial biogenesis, autophagy and mitophagy were not up-regulated during these time points. Activation of biogenesis (rosiglitazone) or autophagy (rapamycin and rilmenidine) improved brain ATP levels and ex vivo oxygen consumption and the long-term cognitive impairment observed in sepsis survivors.Conclusion: Long-term impairment of brain function is temporally related to mitochondrial dysfunction. Activators of autophagy and mitochondrial biogenesis could rescue animals from cognitive impairment.
Assuntos
Disfunção Cognitiva/complicações , Disfunção Cognitiva/patologia , Mitocôndrias/patologia , Sepse/complicações , Sepse/patologia , Animais , Autofagia/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Modelos Animais de Doenças , Masculino , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Dinâmica Mitocondrial/efeitos dos fármacos , Ratos Wistar , Rilmenidina/farmacologia , Rosiglitazona/farmacologia , Sirolimo/farmacologia , Análise de Sobrevida , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genéticaRESUMO
Maple syrup urine disease (MSUD) is caused by an inborn error in metabolism resulting from a deficiency in the branched-chain α-keto acid dehydrogenase complex activity. This blockage leads to accumulation of the branched-chain amino acids (BCAA) leucine, isoleucine and valine, as well as their corresponding α-keto acids and α-hydroxy acids. High levels of BCAAs are associated with neurological dysfunction and the role of pro- and mature brain-derived neurotrophic factor (BDNF) in the neurological dysfunction of MSUD is still unclear. Thus, in the present study we investigated the effect of an acute BCAA pool administration on BDNF levels and on the pro-BDNF cleavage-related proteins S100A10 and tissue plasminogen activator (tPA) in rat brains. Our results demonstrated that acute Hyper-BCAA (H-BCAA) exposure during the early postnatal period increases pro-BDNF and total-BDNF levels in the hippocampus and striatum. Moreover, tPA levels were significantly decreased, without modifications in the tPA transcript levels in the hippocampus and striatum. On the other hand, the S100A10 mRNA and S100A10 protein levels were not changed in the hippocampus and striatum. In the 30-day-old rats, we observed increased pro-BDNF, total-BDNF and tPA levels only in the striatum, whereas the tPA and S100A10 mRNA expression and the immunocontent of S100A10 were not altered. In conclusion, we demonstrated that acute H-BCAA administration increases the pro-BDNF/total-BDNF ratio and decreases the tPA levels in animals, suggesting that the BCAA effect may depend, at least in part, on changes in BDNF post-translational processing.
Assuntos
Aminoácidos de Cadeia Ramificada/administração & dosagem , Fator Neurotrófico Derivado do Encéfalo/biossíntese , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Neostriado/efeitos dos fármacos , Neostriado/metabolismo , Precursores de Proteínas/biossíntese , Animais , Injeções Subcutâneas , Masculino , Ratos , Ratos WistarRESUMO
This study investigates whether ladder climbing (LC), as a model of resistance exercise, can reverse whole-body and skeletal muscle deleterious metabolic and inflammatory effects of high-fat (HF) diet-induced obesity in mice. To accomplish this, Swiss mice were fed for 17 weeks either standard chow (SC) or an HF diet and then randomly assigned to remain sedentary or to undergo 8 weeks of LC training with progressive increases in resistance weight. Prior to beginning the exercise intervention, HF-fed animals displayed a 47% increase in body weight (BW) and impaired ability to clear blood glucose during an insulin tolerance test (ITT) when compared to SC animals. However, 8 weeks of LC significantly reduced BW, adipocyte size, as well as glycemia under fasting and during the ITT in HF-fed rats. LC also increased the phosphorylation of AktSer473 and AMPKThr172 and reduced tumor necrosis factor-alpha (TNF-α) and interleukin 1 beta (IL1-ß) contents in the quadriceps muscles of HF-fed mice. Additionally, LC reduced the gene expression of inflammatory markers and attenuated HF-diet-induced NADPH oxidase subunit gp91phox in skeletal muscles. LC training was effective in reducing adiposity and the content of inflammatory mediators in skeletal muscle and improved whole-body glycemic control in mice fed an HF diet.
Assuntos
Resistência à Insulina , Treinamento Resistido , Tecido Adiposo/metabolismo , Animais , Glicemia/metabolismo , Dieta Hiperlipídica/efeitos adversos , Humanos , Resistência à Insulina/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Músculo Esquelético/metabolismo , Obesidade/metabolismo , Obesidade/terapia , RatosRESUMO
Esophageal cancer is a prominent worldwide illness that is divided into two main subtypes: esophageal squamous cell carcinoma and esophageal adenocarcinoma. Mortality rates are alarming, and the understanding of the mechanisms involved in esophageal cancer development, becomes essential. Purinergic signaling is related to many diseases and among these various types of tumors. Here we studied the effects of the P2Y2 receptor activation in different types of esophageal cancer. Esophageal tissue samples of healthy controls were used for P2Y2R expression quantification. Two human esophageal cancer cell lines Kyse-450 (squamous cell carcinoma) and OE-33 (adenocarcinoma) were used to perform in vitro analysis of cell proliferation, migration, adhesion, and the signaling pathways involved in P2Y2R activation. Data showed that P2Y2R was expressed in biopsies of patients with ESCC and adenocarcinoma, as well as in the two human esophageal cancer cell lines studied. The RT-qPCR analysis demonstrated that OE-33 cells have higher P2RY2 expression than Kyse-450 squamous cell line. Results showed that P2Y2R activation, induced by ATP or UTP, promoted esophageal cancer cells proliferation and colony formation. P2Y2R blockage with the selective antagonist, AR-C 118925XX, led to decreased proliferation, colony formation and adhesion. Treatments with ATP or UTP activated ERK 1/2 pathway in ESCC and ECA cells. The P2Y2R antagonism did not alter the migration of esophageal cancer cells. Interestingly, the esophageal cancer cell lines presented a distinct profile of nucleotide hydrolysis activity. The modulation of P2Y2 receptors may be a promising target for esophageal cancer treatment.
Assuntos
Adenocarcinoma/enzimologia , Carcinoma de Células Escamosas/enzimologia , Proliferação de Células/efeitos dos fármacos , Neoplasias Esofágicas/enzimologia , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Agonistas do Receptor Purinérgico P2Y/farmacologia , Receptores Purinérgicos P2Y2/efeitos dos fármacos , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/patologia , Trifosfato de Adenosina/farmacologia , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/patologia , Adesão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Neoplasias Esofágicas/tratamento farmacológico , Neoplasias Esofágicas/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fosforilação , Antagonistas do Receptor Purinérgico P2Y/farmacologia , Receptores Purinérgicos P2Y2/metabolismo , Transdução de Sinais , Uridina Trifosfato/farmacologiaRESUMO
AIM: This study set forth a question: are there any differences in bone responses to insulin and/or vitamin D3 treatment in female and male type 1 diabetic (T1D) mice? MAIN METHODS: To address this issue, a non-critical sized femur defect was created in streptozotocin (STZ)-T1D mice. Control non-diabetic and T1D female and male mice received: saline; vitamin D3; insulin; or vitamin D3 plus insulin, for 21 days. KEY FINDINGS: Female and male T1D mice showed impaired bone healing, as indicated by histological and micro-computed tomography (micro-CT) analysis. Vitamin D3 or insulin improved the bone regeneration in T1D mice, irrespective of sex. Vitamin D3 plus insulin did not exhibit any additional effects. There were no differences regarding the numbers of TRAP-stained osteoclasts in either evaluated groups. The osteoblast-related gene osterix was upregulated in vitamin D3-treated male T1D mice, as revealed by RT-qPCR. Female T1D mice treated with vitamin D3, insulin, or vitamin D3 plus insulin presented an increased expression of insulin growth factor-1 (IGF-1) mRNA. Conversely, IGF-1 mRNA levels were reduced by the same treatments in male TD1 mice. SIGNIFICANCE: Altogether, the results suggested that T1D similarly delayed the osseous healing in female and male mice, with beneficial effects for either vitamin D3 or insulin in T1D mice of both sexes. However, data indicated marked sex differences regarding the expression of genes implicated in bone formation, in T1D mice treated with vitamin D3 and/or insulin.
Assuntos
Regeneração Óssea/efeitos dos fármacos , Colecalciferol/farmacologia , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Tipo 1/tratamento farmacológico , Insulina/farmacologia , Animais , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Tipo 1/complicações , Feminino , Regulação da Expressão Gênica , Fator de Crescimento Insulin-Like I/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Osteoclastos/metabolismo , Osteogênese/efeitos dos fármacos , Osteogênese/genética , Fatores Sexuais , Estreptozocina , Microtomografia por Raio-XRESUMO
Tyrosinemia type II is an inborn error of metabolism caused by a deficiency in the activity of the enzyme tyrosine aminotransferase, leading to tyrosine accumulation in the body. Although the mechanisms involved are still poorly understood, several studies have showed that higher levels of tyrosine are related to oxidative stress and therefore may affect the cholinergic system. Thus, the aim of this study was to investigate the effects of chronic administration of L-tyrosine on choline acetyltransferase activity (ChAT) and acetylcholinesterase (AChE) in the brain of rats. Moreover, we also examined the effects of one antioxidant treatment (N-acetylcysteine (NAC) + deferoxamine (DFX)) on cholinergic system. Our results showed that the chronic administration of L-tyrosine decreases the ChAT activity in the cerebral cortex, while the AChE activity was increased in the hippocampus, striatum, and cerebral cortex. Moreover, we found that the antioxidant treatment was able to prevent the decrease in the ChAT activity in the cerebral cortex. However, the increase in AChE activity induced by L-tyrosine was partially prevented the in the hippocampus and striatum, but not in the cerebral cortex. Our results also showed no differences in the aversive and spatial memory after chronic administration of L-tyrosine. In conclusion, the results of this study demonstrated an increase in AChE activity in the hippocampus, striatum, and cerebral cortex and an increase of ChAT in the cerebral cortex, without cognitive impairment. Furthermore, the alterations in the cholinergic system were partially prevented by the co-administration of NAC and DFX. Thus, the restored central cholinergic system by antioxidant treatment further supports the view that oxidative stress may be involved in the pathophysiology of tyrosinemia type II.
Assuntos
Acetilcolinesterase/metabolismo , Antioxidantes/farmacologia , Encéfalo/efeitos dos fármacos , Encéfalo/enzimologia , Colina O-Acetiltransferase/metabolismo , Tirosina/toxicidade , Acetilcisteína/farmacologia , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Aprendizagem da Esquiva/fisiologia , Desferroxamina/farmacologia , Masculino , Memória/efeitos dos fármacos , Memória/fisiologia , Fármacos Neuroprotetores/farmacologia , Ratos WistarRESUMO
Studies have shown that changes in energy metabolism are involved in the pathophysiology of bipolar disorder (BD). It was suggested that omega-3 (ω3) fatty acids have beneficial properties in the central nervous system and that this fatty acid plays an important role in energy metabolism. Therefore, the study aimed to evaluate the effect of ω3 fatty acids alone and in combination with lithium (Li) or valproate (VPA) on behaviour and parameters of energy metabolism in an animal model of mania induced by fenproporex. Our results showed that co-administration of ω3 fatty acids and Li was able to prevent and reverse the increase in locomotor and exploratory activity induced by fenproporex. The combination of ω3 fatty acids with VPA was only able to prevent the fenproporex-induced hyperactivity. For the energy metabolism parameters, our results showed that the administration of Fen for the reversal or prevention protocol inhibited the activities of succinate dehydrogenase, complex II and complex IV in the hippocampus. However, hippocampal creatine kinase (CK) activity was decreased only for the reversal protocol. The ω3 fatty acids, alone and in combination with VPA or Li, prevented and reversed the decrease in complex II, IV and succinate dehydrogenase activity, whereas the decrease in CK activity was only reversed after the co-administration of ω3 fatty acids and VPA. In conclusion, our results showed that the ω3 fatty acids combined with VPA or Li were able to prevent and reverse manic-like hyperactivity and the inhibition of energy metabolism in the hippocampus, suggesting that ω3 fatty acids may play an important role in the modulation of behavioural parameters and energy metabolism.
Assuntos
Antimaníacos/uso terapêutico , Comportamento Animal , Transtorno Bipolar/tratamento farmacológico , Transtorno Bipolar/metabolismo , Metabolismo Energético/efeitos dos fármacos , Ácidos Graxos Ômega-3/uso terapêutico , Anfetaminas , Animais , Antimaníacos/farmacologia , Transtorno Bipolar/induzido quimicamente , Transtorno Bipolar/genética , Citrato (si)-Sintase/metabolismo , Creatina Quinase/metabolismo , Modelos Animais de Doenças , Ácidos Graxos Ômega-3/administração & dosagem , Ácidos Graxos Ômega-3/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Lítio/administração & dosagem , Lítio/farmacologia , Lítio/uso terapêutico , Masculino , Ratos Wistar , Succinato Desidrogenase/metabolismo , Ácido Valproico/administração & dosagem , Ácido Valproico/farmacologia , Ácido Valproico/uso terapêuticoRESUMO
The present study aimed to characterize the effects of quinoxaline-derived chalcones, designed on the basis of the selective PI3Kγ inhibitor AS605240, in oral cancer cells. Three lead compounds, namely N9, N17 and N23, were selected from a series of 20 quinoxaline-derived chalcones, based on an initial screening using human and rat squamous cell carcinoma lineages, representing compounds with at least one methoxy radical at the A-ring. The selected chalcones, mainly N9 and N17, displayed marked antiproliferative effects, via apoptosis and autophagy induction, with an increase of sub-G1 population and Akt inhibition. The three chalcones displayed marked in vitro antitumor effects in different protocols with standard chemotherapy drugs, with acceptable toxicity on normal cells. There was no growth retrieval, after exposure to chalcone N9 alone, in a long-term assay to determine the cumulative population doubling (CPD) of human oral cancer cells. A PCR array evaluating 168 genes related to cancer and inflammation, demonstrated striking actions for N9, which altered the expression of 74 genes. Altogether, our results point out quinoxalinic chalcones, mainly N9, as potential strategies for oral cancer treatment.
Assuntos
Carcinoma de Células Escamosas/tratamento farmacológico , Neoplasias Bucais/tratamento farmacológico , Proteínas de Neoplasias/genética , Inibidores de Fosfoinositídeo-3 Quinase , Quinoxalinas/farmacologia , Animais , Apoptose/efeitos dos fármacos , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Chalconas/química , Chalconas/farmacologia , Classe Ib de Fosfatidilinositol 3-Quinase/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Estrutura Molecular , Neoplasias Bucais/genética , Neoplasias Bucais/patologia , Quinoxalinas/química , Ratos , Relação Estrutura-Atividade , Tiazolidinedionas/farmacologiaRESUMO
This study investigated the effects of the long-term dietary fish oil supplementation or the acute administration of the omega-3 fatty acid docosahexaenoic acid (DHA) in the mouse hemorrhagic cystitis (HC) induced by the anticancer drug cyclophosphamide (CYP). HC was induced in mice by a single CYP injection (300mg/kg ip). Animals received four different diets containing 10% and 20% of corn or fish oil, during 21days. Separated groups received DHA by ip (1µmol/kg) or intrathecal (i.t.; 10µg/site) routes, 1h or 15min before CYP. The behavioral tests (spontaneous nociception and mechanical allodynia) were carried out from 1h to 6h following CYP injection. Bladder inflammatory changes, blood cell counts and serum cytokines were evaluated after euthanasia (at 6h). Immunohistochemistry analysis was performed for assessing spinal astrocyte and microglia activation or GPR40/FFAR1 expression. Either fish oil supplementation or DHA treatment (ip and i.t.) markedly prevented visceral pain, without affecting CYP-evoked bladder inflammatory changes. Moreover, systemic DHA significantly prevented the neutrophilia/lymphopenia caused by CYP, whereas this fatty acid did not significantly affect serum cytokines. DHA also modulated the spinal astrocyte activation and the GPR40/FFAR1 expression. The supplementation with fish oil enriched in omega-3 fatty acids or parenteral DHA might be interesting nutritional approaches for cancer patients under chemotherapy schemes with CYP.
Assuntos
Ciclofosfamida/efeitos adversos , Cistite/prevenção & controle , Ácidos Graxos Ômega-3/farmacologia , Hemorragia/prevenção & controle , Dor/prevenção & controle , Animais , Cistite/induzido quimicamente , Cistite/complicações , Cistite/fisiopatologia , Ácidos Graxos Ômega-3/administração & dosagem , Hemorragia/induzido quimicamente , Hemorragia/complicações , Hemorragia/fisiopatologia , Masculino , Camundongos , Dor/etiologia , Peroxidase/metabolismo , Bexiga Urinária/enzimologiaRESUMO
RATIONALE: Several model organisms have been employed to study the impacts of stress on biological systems. Different models of unpredictable chronic stress (UCS) have been established in rodents; however, these protocols are expensive, long-lasting, and require a large physical structure. Our group has recently reported an UCS protocol in zebrafish with several advantages compared to rodent models. We observed that UCS induced behavioral, biochemical, and molecular changes similar to those observed in depressed patients, supporting the translational relevance of the protocol. OBJECTIVES: Considering that a pharmacological assessment is lacking in this zebrafish model, our aim was to evaluate the effects of anxiolytic (bromazepam) and antidepressant drugs (fluoxetine and nortriptyline) on behavioral (novel tank test), biochemical (whole-body cortisol), and molecular parameters (cox-2, tnf-α, il-6, and il-10 gene expression) in zebrafish subjected to UCS. RESULTS: We replicated previous data showing that UCS induces behavioral and neuroendocrine alterations in zebrafish, and we show for the first time that anxiolytic and antidepressant drugs are able to prevent such effects. Furthermore, we extended the molecular characterization of the model, revealing that UCS increases expression of the pro-inflammatory markers cox-2 and il-6, which was also prevented by the drugs tested. CONCLUSIONS: This study reinforces the use of zebrafish as a model organism to study the behavioral and physiological effects of stress. The UCS protocol may also serve as a screening tool for evaluating new drugs that can be used to treat psychiatric disorders with stress-related etiologies.
Assuntos
Ansiolíticos/farmacologia , Antidepressivos/farmacologia , Comportamento Animal/efeitos dos fármacos , Bromazepam/farmacologia , Fluoxetina/farmacologia , Nortriptilina/farmacologia , Estresse Psicológico/metabolismo , Animais , Ciclo-Oxigenase 2/efeitos dos fármacos , Ciclo-Oxigenase 2/metabolismo , Modelos Animais de Doenças , Feminino , Hidrocortisona/metabolismo , Interleucina-10/metabolismo , Interleucina-6/metabolismo , Masculino , Sistemas Neurossecretores/efeitos dos fármacos , Sistemas Neurossecretores/metabolismo , Fator de Necrose Tumoral alfa/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismo , Peixe-ZebraRESUMO
Carnosine (ß-alanyl-L-histidine) is an imidazole dipeptide synthesized in excitable tissues of many animals, whose biochemical properties include carbonyl scavenger, anti-oxidant, bivalent metal ion chelator, proton buffer, and immunomodulating agent, although its precise physiological role(s) in skeletal muscle and brain tissues in vivo remain unclear. The aim of the present study was to investigate the in vivo effects of acute carnosine administration on various aspects of brain bioenergetics of young Wistar rats. The activity of mitochondrial enzymes in cerebral cortex was assessed using a spectrophotometer, and it was found that there was an increase in the activities of complexes I-III and II-III and succinate dehydrogenase in carnosine-treated rats, as compared to vehicle-treated animals. However, quantitative real-time RT-PCR (RT-qPCR) data on mRNA levels of mitochondrial biogenesis-related proteins (nuclear respiratory factor 1 (Nrf1), peroxisome proliferator-activated receptor-γ coactivator 1-α (Ppargc1α), and mitochondrial transcription factor A (Tfam)) were not altered significantly and therefore suggest that short-term carnosine administration does not affect mitochondrial biogenesis. It was in agreement with the finding that immunocontent of respiratory chain complexes was not altered in animals receiving carnosine. These observations indicate that acute carnosine administration increases the respiratory chain and citric acid cycle enzyme activities in cerebral cortex of young rats, substantiating, at least in part, a neuroprotector effect assigned to carnosine against oxidative-driven disorders.
Assuntos
Envelhecimento/metabolismo , Carnosina/farmacologia , Córtex Cerebral/enzimologia , Animais , Carnosina/administração & dosagem , Ciclo do Ácido Cítrico/efeitos dos fármacos , Transporte de Elétrons/efeitos dos fármacos , Masculino , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Fosforilação Oxidativa/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos Wistar , Fatores de Transcrição/metabolismo , Regulação para Cima/efeitos dos fármacosRESUMO
BACKGROUND: Toxic cyanobacterial blooms are recurrent in Patos Lagoon, in southern Brazil. Among cyanotoxins, [D-Leu(1)] microcystin-LR is the predominant variant whose natural cycle involves water and sediment compartments. This study aimed to identify and isolate from sediment a bacterial strain capable of growing on [D-Leu(1)] microcystin-LR. Sediment and water samples were collected at two distinct aquatic spots: close to the Oceanographic Museum (P1), in Rio Grande City, and on São Lourenço Beach (P2), in São Lourenço do Sul City, southern Brazil. METHODS: [D-Leu(1)] microcystin-LR was isolated and purified from batch cultures of Microcystis aeruginosa strain RST9501. Samples of water and sediment from Rio Grande and São Lourenço do Sul were collected. Bacteria from the samples were allowed to grow in flasks containing solely [D-Leu(1)] microcystin-LR. This strain named DMSX was isolated on agar MSM with 8 g L(-1) glucose and further purified on a cyanotoxin basis growth. Microcystin concentration was obtained by using the ELISA immunoassay for microcystins whereas bacterial count was performed by epifluorescence microscopy. The genus Pseudomonas was identified by DNA techniques. RESULTS: Although several bacterial strains were isolated from the samples, only one, DMXS, was capable of growing on [D-Leu(1)] microcystin-LR. The phylogenetic analysis of the 16S rRNA gene from DMXS strain classified the organism as Pseudomonas aeruginosa. DMXS strain incubated with [D-Leu(1)] microcystin-LR lowered the amount of toxin from 1 µg.L(-1) to < 0.05 µg.L(-1). Besides, an increase in the bacterial count-from 71 × 10(5) bacteria.mL(-1) to 117 × 10(5) bacteria.mL(-1)-was observed along the incubation. CONCLUSIONS: The use of bacteria isolated from sediment for technological applications to remove toxic compounds is viable. Studies have shown that sediment plays an important role as a source of bacteria capable of degrading cyanobacterial toxins. This is the first Brazilian report on a bacterium-of the genus Pseudomonas-that can degrade [D-Leu(1)] microcystin-LR, the most frequent microcystin variant in Brazilian freshwaters.
RESUMO
OBJECTIVES: Extracellular purines are a component of the systemic inflammatory response, and their levels are modulated by ectonucleotidases. In addition, nucleotide hydrolysis releases phosphate. We studied serum phosphate levels as a predictor of severity in acute pancreatitis (AP) and their correlation with extracellular purinergic metabolism. METHODS: Acute pancreatitis was induced by the retrograde injection of sodium taurocholate. The AP group was compared with animals submitted to a model of sepsis by cecal ligation and puncture. The sham group was submitted to laparotomy and closure. We measured the phosphate and purine levels in serum and the expression of 5'-nucleotidase (CD73) and the adenosine A2a receptor in pancreatic tissue by quantitative real-time polymerase chain reaction. RESULTS: Serum phosphate levels were higher in severe AP and correlated with severity. Severe AP led to increased serum levels of adenosine diphosphate, adenosine monophosphate, and adenosine. In addition, adenosine monophosphate conversion to adenosine in serum was accelerated in the AP groups. We found a positive correlation between serum adenosine and phosphate in the AP groups. The expression levels of CD73 and the adenosine A2a receptor in the pancreas were not altered. CONCLUSIONS: Our study suggests that serum phosphate correlates with severity in AP and implicates extracellular purines in the systemic response to severe AP.
Assuntos
Pancreatite/sangue , Fosfatos/sangue , Purinas/sangue , Índice de Gravidade de Doença , 5'-Nucleotidase/metabolismo , Doença Aguda , Animais , Biomarcadores/sangue , Estudos de Casos e Controles , Masculino , Pâncreas/metabolismo , Pancreatite/metabolismo , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase em Tempo RealRESUMO
AIMS: Schizophrenia is a debilitating neurodevelopmental disorder that is associated with dysfunction in the cholinergic system. Early prevention is a target of treatment to improve long-term outcomes. Therefore, we evaluated the preventive effects of omega-3 fatty acids on AChE activity in the prefrontal cortex, hippocampus and striatum in an animal model of schizophrenia. MAIN METHODS: Young Wistar rats (30 days old) were initially treated with omega-3 fatty acids or vehicle alone. Animals received ketamine to induce an animal model of schizophrenia or saline plus omega-3 fatty acids or vehicle alone for 7 consecutive days beginning on day 15. A total of 22 days elapsed between the treatment and intervention. Animals were sacrificed, and brain structures were dissected to evaluate AChE activity and gene expression. KEY FINDINGS: Our results demonstrate that ketamine increased AChE activity in these three structures, and omega-3 fatty acids plus ketamine showed lower values for the studied parameters, which indicate a partial preventive mechanism of omega-3 fatty acid supplementation. We observed no effect on AChE expression. Together, these results indicate that omega-3 fatty acid supplementation effectively reduced AChE activity in an animal model of schizophrenia in all studied structures. In conclusion, the present study provides evidence that ketamine and omega-3 fatty acids affect the cholinergic system, and this effect may be associated with the physiopathology of schizophrenia. Further studies are required to investigate the mechanisms that are associated with this effect.
Assuntos
Acetilcolinesterase/metabolismo , Antagonistas de Aminoácidos Excitatórios/farmacologia , Ácidos Graxos Ômega-3/farmacologia , Ketamina/antagonistas & inibidores , Ketamina/farmacologia , Esquizofrenia/enzimologia , Acetilcolinesterase/genética , Animais , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Hipocampo/enzimologia , Masculino , Neostriado/efeitos dos fármacos , Neostriado/enzimologia , Córtex Pré-Frontal/efeitos dos fármacos , Córtex Pré-Frontal/enzimologia , Ratos , Ratos Wistar , Esquizofrenia/induzido quimicamenteRESUMO
Paraquat (PQ) is an agrochemical agent commonly used worldwide, which is allied to potential risks of intoxication. This herbicide induces the formation of reactive oxygen species (ROS) that ends up compromising various organs, particularly the lungs and the brain. This study evaluated the deleterious effects of paraquat on the central nervous system (CNS) and peripherally, with special attempts to assess the putative protective effects of the selective CXCR2 receptor antagonist SB225002 on these parameters. PQ-toxicity was induced in male Wistar rats, in a total dose of 50 mg/kg, and control animals received saline solution at the same schedule of administration. Separate groups of animals were treated with the selective CXCR2 antagonist SB225002 (1 or 3 mg/kg), administered 30 min before each paraquat injection. The major changes found in paraquat-treated animals were: decreased body weight and hypothermia, nociception behavior, impairment of locomotor and gait capabilities, enhanced TNF-α and IL-1ß expression in the striatum, and cell migration to the lungs and blood. Some of these parameters were reversed when the antagonist SB225002 was administered, including recovery of physiological parameters, decreased nociception, improvement of gait abnormalities, modulation of striatal TNF-α and IL-1ß expression, and decrease of neutrophil migration to the lungs and blood. Taken together, our results demonstrate that damage to the central and peripheral systems elicited by paraquat can be prevented by the pharmacological inhibition of CXCR2 chemokine receptors. The experimental evidence presented herein extends the comprehension on the toxicodynamic aspects of paraquat, and opens new avenues to treat intoxication induced by this herbicide.
Assuntos
Encéfalo/efeitos dos fármacos , Herbicidas/farmacologia , Paraquat/farmacologia , Compostos de Fenilureia/farmacologia , Receptores de Interleucina-8B/antagonistas & inibidores , Animais , Comportamento Animal/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Encéfalo/metabolismo , Movimento Celular/efeitos dos fármacos , Quimiocinas/metabolismo , Corpo Estriado/efeitos dos fármacos , Corpo Estriado/metabolismo , Marcha/efeitos dos fármacos , Hipotermia/induzido quimicamente , Hipotermia/metabolismo , Interleucina-1beta/metabolismo , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Masculino , Atividade Motora/efeitos dos fármacos , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Receptores de Interleucina-8B/metabolismo , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Chronic exposure to paraquat (Pq), a toxic herbicide, can result in Parkinsonian symptoms. This study evaluated the effect of the systemic administration of Pq on locomotion, learning and memory, social interaction, tyrosine hydroxylase (TH) expression, dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC) levels, and dopamine transporter (DAT) gene expression in zebrafish. Adult zebrafish received an i.p. injection of either 10 mg/kg (Pq10) or 20 mg/kg (Pq20) of Pq every 3 days for a total of six injections. Locomotion and distance traveled decreased at 24 h after each injection in both treatment doses. In addition, both Pq10- and Pq20-treated animals exhibited differential effects on the absolute turn angle. Nonmotor behaviors were also evaluated, and no changes were observed in anxiety-related behaviors or social interactions in Pq-treated zebrafish. However, Pq-treated animals demonstrated impaired acquisition and consolidation of spatial memory in the Y-maze task. Interestingly, dopamine levels increased while DOPAC levels decreased in the zebrafish brain after both treatments. However, DAT expression decreased in the Pq10-treated group, and there was no change in the Pq20-treated group. The amount of TH protein showed no significant difference in the treated group. Our study establishes a new model to study Parkinson-associated symptoms in zebrafish that have been chronically treated with Pq.
Assuntos
Comportamento Animal/efeitos dos fármacos , Dopamina/metabolismo , Proteínas de Peixes/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Herbicidas/toxicidade , Paraquat/toxicidade , Peixe-Zebra/fisiologia , Ácido 3,4-Di-Hidroxifenilacético/metabolismo , Animais , Proteínas da Membrana Plasmática de Transporte de Dopamina/genética , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Proteínas de Peixes/metabolismo , Reação em Cadeia da Polimerase , Tirosina 3-Mono-Oxigenase/genética , Tirosina 3-Mono-Oxigenase/metabolismo , Peixe-Zebra/genética , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismoRESUMO
Tyrosinemia type II, which is also known as Richner-Hanhart syndrome, is an inborn error of metabolism that is due to a block in the transamination reaction that converts tyrosine to p-hydroxyphenylpyruvate. Because the mechanisms of neurological dysfunction in hypertyrosinemic patients are poorly known and the symptoms of these patients are related to the central nervous system, the present study evaluated brain-derived neurotrophic factor (BDNF) levels and bdnf mRNA expression in young rats and during growth. In our acute protocol, Wistar rats (10 and 30 days old) were killed 1 h after a single intraperitoneal L-tyrosine injection (500 mg/kg) or saline. Chronic administration consisted of L-tyrosine (500 mg/kg) or saline injections 12 h apart for 24 days in Wistar rats (7 days old), and the rats were killed 12 h after the last injection. The brains were rapidly removed, and we evaluated the BDNF levels and bdnf mRNA expression. The present results showed that the acute administration of L-tyrosine decreased both BDNF and bdnf mRNA levels in the striatum of 10-day-old rats. In the 30-day-old rats, we observed decreased BDNF levels without modifications in bdnf transcript level in the hippocampus and striatum. Chronic administration of L-tyrosine increased the BDNF levels in the striatum of rats during their growth, whereas bdnf mRNA expression was not altered. We hypothesize that oxidative stress can interact with the BDNF system to modulate synaptic plasticity and cognitive function. The present results enhance our knowledge of the pathophysiology of hypertyrosinemia.
Assuntos
Fator Neurotrófico Derivado do Encéfalo/biossíntese , Encéfalo/metabolismo , Regulação da Expressão Gênica , RNA Mensageiro/biossíntese , Tirosina/administração & dosagem , Animais , Encéfalo/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos/métodos , Masculino , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Ratos , Ratos WistarRESUMO
Maple syrup urine disease (MSUD) is a neurometabolic disorder caused by deficiency of the activity of the mitochondrial enzyme complex branched-chain α-keto acid dehydrogenase leading to accumulation of the branched-chain amino acids (BCAA) and their corresponding branched-chain α-keto acids. In this study, we examined the effects of acute and chronic administration of BCAA on protein levels and mRNA expression of nerve growth factor (NGF) considering that patients with MSUD present neurological dysfunction and cognitive impairment. Considering previous observations, it is suggested that oxidative stress may be involved in the pathophysiology of the neurological dysfunction of MSUD. We also investigated the influence of antioxidant treatment (N-acetylcysteine and deferoxamine) in order to verify the influence of oxidative stress in the modulation of NGF levels. Our results demonstrated decreased protein levels of NGF in the hippocampus after acute and chronic administration of BCAA. In addition, we showed a significant decrease in the expression of ngf in the hippocampus only following acute administration in 10-day-old rats. Interestingly, antioxidant treatment was able to prevent the decrease in NGF levels by increasing ngf expression. In conclusion, the results suggest that BCAA is involved in the regulation of NGF in the developing rat. Thus, it is possible that alteration of neurotrophin levels during brain maturation could be of pivotal importance in the impairment of cognition provoked by BCAA. Moreover, the decrease in NGF levels was prevented by antioxidant treatment, reinforcing that the hypothesis of oxidative stress can be an important pathophysiological mechanism underlying the brain damage observed in MSUD.
Assuntos
Aminoácidos de Cadeia Ramificada/administração & dosagem , Aminoácidos de Cadeia Ramificada/farmacologia , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Fator de Crescimento Neural/metabolismo , Animais , Antioxidantes/metabolismo , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Masculino , Neostriado/efeitos dos fármacos , Neostriado/metabolismo , Fator de Crescimento Neural/genética , Ratos , Ratos WistarRESUMO
Maple syrup urine disease is an inherited metabolic disease predominantly characterized by neurological dysfunction. However, the mechanisms underlying the neuropathology of this disease are still not defined. Therefore, the aim of this study was to investigate the effect of acute and chronic administration of a branched-chain amino acids (BCAA) pool (leucine, isoleucine, and valine) on acetylcholinesterase (AChE) activity and gene expression in the brain and serum of rats and to assess if antioxidant treatment prevented the alterations induced by BCAA administration. Our results show that the acute administration of a BCAA pool in 10- and 30-day-old rats increases AChE activity in the cerebral cortex, striatum, hippocampus, and serum. Moreover, chronic administration of the BCAA pool also increases AChE activity in the structures studied, and antioxidant treatment prevents this increase. In addition, we show a significant decrease in the mRNA expression of AChE in the hippocampus following acute administration in 10- and 30-day-old rats. On the other hand, AChE expression increased significantly after chronic administration of the BCAA pool. Interestingly, the antioxidant treatment was able to prevent the increased AChE activity without altering AChE expression. In conclusion, the results from the present study demonstrate a marked increase in AChE activity in all brain structures following the administration of a BCAA pool. Moreover, the increased AChE activity is prevented by the coadministration of N-acetylcysteine and deferoxamine as antioxidants.
Assuntos
Acetilcolinesterase/sangue , Aminoácidos de Cadeia Ramificada/metabolismo , Antioxidantes/farmacologia , Química Encefálica/fisiologia , Doença da Urina de Xarope de Bordo/tratamento farmacológico , Doença da Urina de Xarope de Bordo/enzimologia , Acetilcolinesterase/genética , Aminoácidos de Cadeia Ramificada/toxicidade , Animais , Antioxidantes/uso terapêutico , Química Encefálica/efeitos dos fármacos , Modelos Animais de Doenças , Masculino , Doença da Urina de Xarope de Bordo/induzido quimicamente , Ratos , Ratos WistarRESUMO
Tyrosinemia is a rare genetic disease caused by mutations on genes that codify enzymes responsible for tyrosine metabolism. Considering that tyrosinemics patients usually present symptoms associated with central nervous system alterations that ranges from slight decreases in intelligence to severe mental retardation, we decided to investigate whether acute and chronic administration of L-tyrosine in rats would affect acetylcholinesterase mRNA expression and enzymatic activity during their development. In our acute protocol, Wistar rats (10 and 30 days old) were killed one hour after a single intraperitoneal L-tyrosine injection (500 mg/kg) or saline. Chronic administration consisted of L-tyrosine (500 mg/kg) or saline injections 12 h apart for 24 days in Wistar rats (7 days old) and rats were killed 12 h after last injection. Acetylcholinesterase activity was measured by Ellman's method and acetylcholinesterase expression was carried out by a semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) assay. We observed that acute (10 and 30 days old rats) and chronic L-tyrosine administration increased acetylcholinesterase activity in serum and all tested brain areas (hippocampus, striatum and cerebral cortex) when compared to control group. Moreover, there was a significant decrease in mRNA levels of acetylcholinesterase in hippocampus was observed after acute protocol (10 and 30 days old rats) and in striatum after chronic protocol. In case these alterations also occur in the brain of the patients, our results may explain, at least in part, the neurological sequelae associated with high plasma concentrations of tyrosine seen in patients affected by tyrosinemia type II.