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Objectives: Stress elicits physiological and neuroendocrine responses mediated by the hypothalamic-pituitary-adrenal (HPA) axis and lateral hypothalamus (LH). However, prolonged stress can dysregulate neuropeptide systems like orexin. This study investigated the effects of temporary and prolonged stress on HPA activity and orexin processing in the rat LH. Materials and Methods: Male Wistar rats were exposed to various stress repetitions. The stress paradigm is defined as short (acute; 1 day and mild; 3 days) and long (sub-chronic; 10 days and chronic; 21 days)-term 6 hr daily restraint stress. Plasma corticosterone (CORT) served as an index of HPA function. Expression of prepro-orexin and its processing enzymes prohormone convertases (PC) 1 and 2 was measured in LH tissues using semiquantitative RT-PCR. Results: The plasma level of CORT was elevated following mild, sub-chronic, and chronic, but not acute stress versus unstressed controls. The expression of prepro-orexin was heightened following all stress exposures. However, PC1 increased and PC2 decreased only after prolonged stress. The PC1/PC2 ratio was also selectively augmented with sub-chronic and chronic stress, implying impaired orexin maturation. Conclusion: Together, these data demonstrate that the HPA axis and lateral hypothalamic orexin system respond to stress based on stress repetition. Changes in orexin processing enzyme mRNA, exclusively after chronic stress, imply potential effects on peptide maturation, requiring confirmation of the orexin production at the protein level.
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BACKGROUND AND AIM: Early-life stressful situations and binge drinking have been thus far acknowledged as two burdensome conditions that potentially give rise to negative outcomes and then synergistically affect brain development. In this context, the hippocampus, with the greatest number of glucocorticoid receptors (GCRs) in the brain, is responsible for regulating negative responses to stress. Prolonged glucocorticoid (GC) exposure can accordingly cause oxidative stress (OS), leading to cognitive and emotional dysfunction. Against this background, melatonin, as a powerful antioxidant and hypothalamus-pituitary-adrenal (HPA) axis regulator, was administered in this study to ameliorate cognitive impairments induced by perinatal ethanol and stress exposure in adolescent male rat progeny. METHODS: Wistar rat dams were exposed to ethanol (4 g/kg) and melatonin (10 mg/kg) from gestational day (GD) 6 to postnatal day (PND) 14 and then limited nesting material (LNS) from PND0 to PND14 individually or in combination. Maternal behavior was then investigated in mothers. Afterward, the plasma corticosterone (CORT) concentration, the OS marker, the corticotropin-releasing hormone receptor type 1 (CRHR1) expression, and the GCR and brain-derived neurotrophic factor (BDNF) levels were measured in the male pups. Moreover, behavioral tasks, including the elevated plus maze (EPM), the Morris water maze (MWM), the novel object recognition (NORT), and the object-location memory (OLM) tests were completed and assessed. RESULTS: The quantity and quality of maternal care significantly decreased in the mothers with dual exposure to ethanol and stress. The plasma CORT concentration in the progeny also dropped in the Ethanol + LNS group, but the risk-taking behavior elevated significantly. The ethanol and stress exposure further revealed a significant fall in the GCR and CRHR1 expression levels, compared with stress alone. The results of learning and memory tasks also indicated a significant reduction in spatial learning and memory among animals exposed to ethanol and stress. The BDNF mRNA levels correspondingly increased in the Ethanol + LNS group, compared with LNS alone. In the presence of ethanol and stress, the superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities correspondingly declined. On the other hand, the malondialdehyde (MDA) levels augmented in the hippocampus of the animals with ethanol and LNS dual exposure, as compared with the control group. Melatonin treatment (MT) thus improved nursing behaviors in dams, prevented OS, enhanced the CRHR1 and GCR expression, and reduced the BDNF levels to the similar ones in the control group. The animals in the Ethanol + LNS + MT group ultimately showed an ameliorated performance at behavioral tasks, including the memory and risk-taking behavior. CONCLUSION: It was concluded that MT could prevent stress response and memory impairments arising from dual exposure to ethanol and stress by inhibiting OS.
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Melatonina , Gravidez , Feminino , Ratos , Animais , Masculino , Melatonina/farmacologia , Melatonina/metabolismo , Ratos Wistar , Etanol/toxicidade , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Antioxidantes/metabolismo , Aprendizagem Espacial , Hipocampo/metabolismo , Aprendizagem em LabirintoRESUMO
INTRODUCTION: The important role of Dipeptidyl Peptidase IV (DPPIV) has been reported in tumour progression of several human cancers. This study demonstrates the DPPIV mRNA expression level and activity in tumour and paired non-tumour tissues of oral squamous cell carcinoma (OSCC) patients and the potential modulation of DPPIV in the metastasis of tumour through regulating MMP2 and MMP9 activities. MATERIALS AND METHODS: This study was conducted on 16 OSCC patients. The mRNA expression level of DPPIV was evaluated by RT-qPCR in tumour of OSCC patientsand compared with their paired non-tumour tissues. Additionally, DPPIV activity was measured in serum, tumour and paired non-tumour tissues of OSCC patients. Zymography was performed to measure and compare the activities of MMP2 and MMP9 between tumour and paired non-tumour tissues of OSCC patients. RESULTS: The results showed significantly higher DPPIV mRNA level and activity in tumour of OSCC patients compared to their paired non-tumour tissues. Tumour DPPIV mRNA expression and activity were positively correlated with activities of MMP2 and MMP9, respectively. Serum DPPIV activity of OSCC patients was lower compared to healthy control and did not show correlation with tumour DPPIV mRNA level. CONCLUSION: These data indicate that secreted DPPIV may not originate from the tumour tissue of OSCC patients. Furthermore, increased DPPIV gene expression and activity in tumour of OSCC patients might be involved in the ECM degradation and invasion of OSCC through regulation of MMP2 and MMP9 activities.
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Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , Neoplasias Bucais , Humanos , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Dipeptidil Peptidase 4/genética , Metaloproteinase 2 da Matriz/genética , Metaloproteinase 9 da Matriz/genética , Metaloproteinase 9 da Matriz/metabolismo , Neoplasias Bucais/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Carcinoma de Células Escamosas de Cabeça e PescoçoRESUMO
Introduction: Stress is a reaction to unwanted events disturbing body homeostasis and its pathways and target areas. Stress affects the brain through the lateral hypothalamic area (LHA), the orexinergic system that mediates the effect of corticotropin-releasing hormone (CRH) through CRH Receptor Type 1 (CRHr1). Therefore, this study explores the outcome of stress exposure on anxiety development and the involvement of the LHA through LHA-CRHr1. Methods: Male Wistar rats (220-250 g) implanted with a cannula on either side of the LHA received acute or chronic stress. Subsequently, exploratory behavior was examined using the Open Field (OF), and anxiety was tested by Elevated Plus Maze (EPM). Before sacrifice, the cerebrospinal fluid (CSF) and the blood were sampled. Nissl stain was performed on fixed brain tissues. Results: Acute stress reduced exploration in of and increased anxiety in EPM. LHA-CRHr1 inhibition reversed the variables to increase the exploration and decrease anxiety. In contrast, chronic stress did not show any effect on anxiety-related behaviors. Chronic stress decreased the cell population in the LHA, which was prevented by the CRHr1 inhibition. However, the CRHr1 inhibition could not reverse the chronic stress-induced increase in the CSF orexin level. Furthermore, plasma corticosterone levels increased through acute or chronic stress, impeded by the inhibition of CRHr1. Conclusion: Our results recognize LHA-CRHr1 as a capable candidate that modulates acute stress-induced anxiety development and chronic stress-induced changes in the cellular population of the region. Highlights: Acute stress, increased immobility of the rat in open field and elevated plus maze.Chronic stress, increased orexin production while decreasing neuronal survival.The anxiety and immobility were not developed in presence of CRHr1.CRHr1 blocking reversed the chronic stress changes in corticosterone and orexin. Plain Language Summary: Lateral Hypothalamus (LH) is a region involved in sleep and appetite regulation and recently known to play role in stress pathophysiology. The stress mediating function of the LH is performed through Corticotropin Releasing Hormone Receptor type-1 (CRHr1). This study explored the role of LH- CRHr1 in anxiety development and orexin production. Acute and chronic stress affected the behavior and molecular changes, differently. The acute stress increased the anxiety condition, while the chronic stress could only change the molecular criteria. Although we assumed that the inability of the chronic stress to develop anxiety may be attributable to habituation, the chronic stress could increase the plasma corticosterone and orexin level. All of the stress mal-changes in behavior and molecular level prevented by antagonising CRHr1 in the LH, indicating a gating function of LH-CRHr1 for stress development.
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INTRODUCTION: Seizures may result from the hyperexcitable neuronal activity of the brain. Multiple neurotransmitter receptors, including orexin (OX) and endocannabinoids interfere with forming the synaptic responses linked to the seizures. Therefore, this study investigates the involvement of OX-1 (OX1R) and endocannbinoid-1 (CB1R) receptors in the kainate- induced excitability in the synaptic field responses. MATERIAL AND METHODS: Theta pattern used to stimulate Schaffer collaterals and then metal microelectrodes to record the CA1 field excitatory postsynaptic potentials (fEPSPs). Input/ output stimulation and responses and paired- pulse (PP) stimuli employed to measure the state of synaptic activity in normal and kainate- induced seizure-like hyperexcitable activities and the slope of fEPSPs used as a measure of the change in the synaptic activity. Furthermore, agonists and antagonists of OX and endocannabinoids infused to investigate the involvement of their receptors. RESULT: The results showed that kainate application increased the fEPSP slope either in input stimuli with different intensities/output synaptic responses (I/O), or test pulse stimulated baseline synaptic responses (BSR) and, hence, increased the excitability of field responses in the CA1 region. However, neither kainate nor theta burst stimulation (TBS) could alter the PP stimuli -induced synaptic responses. TBS increased the fEPSP slope of the kainate-applied I/O and BSR, however, the increase was not high enough in BSR to be classified as long-term potentiation (LTP). The single-antagonist OX1R and CB1R administration prevented TBS- induced potentiation and partially recovered the effect by adding eCB or OX agonists in kainate-injected animals. In contrast, OX or combined eCB-OX antagonist application group demonstrated nearly full recovery of LTP induction. CONCLUSION: Our study concludes that blockade of OX1 or CB1 prevents the induction of LTP, and OX infusion or both receptor blockade recovers the LTP.
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Endocanabinoides , Potenciação de Longa Duração , Animais , Região CA1 Hipocampal , Estimulação Elétrica/métodos , Endocanabinoides/farmacologia , Hipocampo , Ácido Caínico/farmacologia , Potenciação de Longa Duração/fisiologia , Orexinas/farmacologia , ConvulsõesRESUMO
Both prenatal ethanol and early-life stress have been shown to induce reduced risk-taking and explorative behavior as well as cognitive dysfunction in the offspring. In this study, we examined the effect of combined exposure to ethanol and early stress on maternal care, exploratory behavior, memory performances, and oxidative stress in male offspring. Pregnant rats were exposed to ethanol (4 g/kg) from gestational day (GD) 6-to postnatal day (PND) 14 and limited nesting material (LNS) from PND0-PND14 individually or in combination. Maternal behavior was evaluated during diurnal cycle. The level of corticosterone hormone and markers of oxidative stress were evaluated in the pups. Risk-taking and explorative behavior were assessed with the elevated-plus maze (EPM) test and cognitive behavior with the Morris water maze (MWM), novel object recognition (NORT), and object location memory (OLM) tests. In the mothers, perinatal alcohol or LNS either alone or in combination decreased maternal behavior. In the offspring, the combination of the two factors significantly increased the pup's plasma corticosterone concentration in comparison with ethanol and LNS alone. Reduced risk-taking behavior was observed in the ethanol, LNS and ethanol + LNS groups compared with the control group, and this was amplified in the co-exposure of ethanol and LNS groups. The MWM, NORT, and OLM tests revealed spatial and recognition memory impairment in the ethanol and LNS groups. This impairment was more profound in the co-exposure of ethanol and LNS. Also, we observed a significant decrease in superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities and an increase in malondialdehyde (MDA) level in the hippocampus of ethanol and LNS co-exposed animals as compared with individual exposure of ethanol and LNS. While each factor independently produced similar outcomes, the results indicate that the dual exposure paradigm could significantly strengthen the outcomes.
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Experiências Adversas da Infância , Efeitos Tardios da Exposição Pré-Natal , Animais , Antioxidantes/farmacologia , Cognição , Corticosterona , Etanol/toxicidade , Feminino , Hipocampo , Humanos , Masculino , Aprendizagem em Labirinto , Estresse Oxidativo , Gravidez , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Ratos , Ratos Wistar , Assunção de RiscosRESUMO
Homocysteine (Hcy) is an excitatory amino acid that contains thiol group and derives from the methionine metabolism. It increases vulnerability of the neuronal cells to excitotoxic and oxidative damage. This study aimed to investigate the hyperhomocysteinemia (hHcy) effects on rat cerebellum and the possible protective role of quercetin administration in Hcy-treated rats, using behavioral and biochemical analyzes. To this end, the adult male rats were divided randomly into the control group that received vehicle, Hcy group received Hcy (400 µg/kg), Hcy + Que group received Hcy + quercetin (50 mg/kg), quercetin group received quercetin for 14 days. On Day 14 after the final treatment, lipid peroxidation level, the superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities were evaluated in the cerebellum. After completion of treatment, the rat's performance on rotarod and locomotor activity was evaluated. The results showed that Hcy treatment elicited cerebellar lipid peroxidation, impaired locomotor activity and increased latency to fall on the rotarod. Quercetin failed to attenuate significantly motoric impairment, increased significantly the cerebellar lipid peroxidation and GPx activity in the Hcy + Que group. Our results suggest that Hcy induced cerebellar toxicity and quercetin had no significant protective effects against Hcy toxicity in the cerebellum of adult rats.
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Alcohol consumption during pregnancy damages the central nervous system of developing fetus and results in persistent physical and neurobehavioral abnormalities, including learning and memory disorders. The hippocampus which is involved in learning and memory is highly susceptible to the ethanol neurotoxic effects. Oxidative stress is one of the mechanisms in alcohol-induced disorders. Ethanol also interferes with the brain-derived neurotrophic factors (BDNF) expression. Using vitamin E as a potent antioxidant, we studied the possible interrelation between oxidative stress and BDNF on cognition. Ethanol (4 g/kg) and vitamin E (100, 200, and 400 mg/kg) were given to pregnant Wistar rats on first day of gestation (GD) until weaning (28 days). Oxidative stress marker, BDNF expression, and cyclic AMP-response binding-protein (CREB) expression levels were measured on postnatal days (PND) 28. Object location memory (OLM) was evaluated on PND 34. Our results demonstrated that ethanol exposure significantly reduced glutathione peroxidase (GPx) activity, reduced glutathione (GSH), reduced/oxidized glutathione (GSH/GSSG) ratio, and increased superoxide dismutase (SOD) activity, malondialdehyde (MDA) levels, and carbonyl protein content in the hippocampus. Total BDNF, BDNF mRNA, and CREB expression significantly reduced in the hippocampus by ethanol exposure. Also, ethanol significantly reduced the discrimination index (DI) in the OLM test. In addition, vitamin E administration could reduce oxidative stress, increase significantly BDNF and CREB levels, and improve cognitive dysfunction induced by ethanol exposure. Collectively, results suggest that probably oxidative stress can interrelate with the BDNF system for modulating cognitive function in the ethanol-exposed rat.
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Comportamento Animal/efeitos dos fármacos , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Cognição/efeitos dos fármacos , Etanol/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Vitamina E/farmacologia , Animais , Catalase/metabolismo , Feminino , Glutationa Peroxidase/metabolismo , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Exposição Materna , Gravidez , Ratos , Ratos Wistar , Superóxido Dismutase/metabolismoRESUMO
It is known that hippocampal epileptogenesis is accompanied by hyperexcitability, glutamate-related neuronal dysfunctions and consequently cognitive deficits. However, the neuroprotective role of astrocytic glutamate uptake through the Glutamate Transporter-1 (GLT-1) remains to be unknown in these processes. Therefore, to assess the effect of glutamate uptake, pharmacological upregulation of GLT-1 using ceftriaxone administration (200 mg/kg/day, i.p, 5 days) was utilized in Li-PIL animal models of temporal lobe epilepsy (TLE). Glutamate concentration and glutamine synthetase activity were analyzed using biochemical assays. In addition, GLT-1 gene expression was assessed by RT-qPCR. Finally, cognitive function was studied using Morris water maze (MWM) test and novel object recognition task (NORT). Our results demonstrated that the acute phase of epileptogenesis (first 72 hours after Status Epilepticus) was accompanied by an increase in the hippocampal glutamate and downregulation of GLT-1 mRNA expression compared to controls. Ceftriaxone administration in epileptic animals led to a reduction of glutamate along with elevation of the level of glutamine synthetase activity and GLT-1 expression in the acute phase. In the chronic phase of epileptogenesis (4 weeks after Status Epilepticus), glutamate levels and GLT-1 expression were decreased compared to controls. Ceftriaxone treatment increased the levels of GLT-1 expression. Furthermore, impaired learning and memory ability in the chronic phase of epileptogenesis was rescued by Ceftriaxone administration. This study shows that astrocytic glutamate uptake can profoundly impact the processes of hippocampal epileptogenesis through the reduction of glutamate-induced excitotoxicity and consequently rescuing of cognitive deficits caused by epilepsy.
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Disfunção Cognitiva/tratamento farmacológico , Epilepsia do Lobo Temporal/metabolismo , Transportador 2 de Aminoácido Excitatório/metabolismo , Regulação para Cima/efeitos dos fármacos , Animais , Ceftriaxona/farmacologia , Ceftriaxona/uso terapêutico , Disfunção Cognitiva/metabolismo , Modelos Animais de Doenças , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Ratos , Ratos Wistar , Reconhecimento Psicológico/efeitos dos fármacos , Resultado do TratamentoRESUMO
OBJECTIVE: The early life environment is critical for normal growth and development for future reproductive function. This study aims to investigate the effect of neonatal maternal separation (MS) on gelatinase activity of mouse ovarian follicles. MATERIALS AND METHODS: In this experimental study, infants from female NMRI mice were randomly allocated into two groups immediately after birth: i. MS isolated from their mothers for 6 hours per day, from postpartum days 2 to 16) and ii. Control (undisturbed during the 16 days). Ovarian tissues were dissected to perform differential counts of the ovarian follicle type by haematoxylin and eosin staining. The isolated follicles were cultured for 12 days. Gelatinase activity and the gene expressions of matrix metalloproteinases, MMP2 and MMP9, and their tissue inhibitors, TIMP1 and TIMP2, were evaluated by zymography and real-time polymerase chain reaction (PCR), respectively. RESULTS: Follicle counts at the different developmental stages were significantly different between the control and MS groups. There was a significant decrease in gelatinase activity in the MS group compared to the control group. The MS group showed significantly decreased gene expression levels of MMP2 and MMP9 compared to the control group. In contrast, the gene expression levels of TIMP1 and TIMP2 significantly increased in the MS group compared to the control group. CONCLUSION: MS is a stressor agent that compromises ovarian follicle development, at least via disruption of gelatinase activity and its related gene expressions.
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Objective: Alcohol exposure during pregnancy affects the developing fetus and causes a variety of physical and neurological abnormalities. Here we aim to study the effects of vitamin E on spatial learning and memory deficits and on changes in hippocampal brain-derived neurotrophic factor (BDNF) levels following perinatal ethanol exposure in rats.Method: Pregnant Wistar rats received ethanol (4â g/kg) and vitamin E (doses of 100, 200, and 400â mg/kg) on day 0 of gestation (GD) until weaning (28 days). On postnatal days (PND) 29, the performance of spatial learning and memory of rats were measured using the Morris water maze (MWM). The expression of BDNF protein levels in the hippocampus was assayed using BDNF ELISA kits.Results: Ethanol exposed group showed higher escape latency during training, reduced time spent in the target quadrant, higher escape location latency and average proximity in probe test. Vitamin E with doses of 100, 200 and 400â mg/kg significantly reduced escape latency during training. Also, vitamin E (400â mg/kg) significantly increased time spent in target quadrant, decreased escape location latency and average proximity in probe test. Maternal ethanol treatment significantly reduced the expression of BDNF protein in the hippocampus of offspring, whereas administration of vitamin E (400â mg/kg) significantly increased hippocampal BDNF in ethanol-treated rats.Discussion: Vitamin E administration dose-dependently ameliorate learning and memory deficits induced by perinatal ethanol exposure and increased hippocampal BDNF levels. BDNF may be implicated in the beneficial effects of vitamin E on learning and memory in the perinatal ethanol-exposed rat.
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Fator Neurotrófico Derivado do Encéfalo , Etanol , Animais , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Etanol/farmacologia , Feminino , Hipocampo/metabolismo , Aprendizagem em Labirinto , Transtornos da Memória/induzido quimicamente , Transtornos da Memória/tratamento farmacológico , Transtornos da Memória/prevenção & controle , Gravidez , Ratos , Ratos Wistar , Vitamina ERESUMO
Understanding the mechanisms underlying memory is essential for the treatment of post-traumatic stress disorder (PTSD). Orexin, as a lateral hypothalamic (LH) neuropeptide, interferes with the stages of memory, primarily through the orexin receptor1 (Orx1R). The aim of this study was to evaluate the effects of amygdala Orx1R in the acquisition and extinction processes of PTSD modeled in animals. In three experiments, rats were divided into three groups: control (Naïve), shock (receiving a foot shock), and PTSD (experiencing Single prolonged stress (SPS) method). The first experiment aimed to evaluate LH activity in PTSD modeled rats. The second and third experiments aimed to evaluate the effects of Orx1R in the acquisition and extinction of fear memory in PTSD modeled animals. SB334867 (SB) or its solvent was microinjected into the amygdala and the rats were subjected to conditioning thereafter. In the second group, we used a single injection after conditioning. In the third group, we used three consecutive injections (one after each memory test). Some behaviors and Orx1R expression were evaluated. The freezing response was significantly longer in the PTSD group than on the control. Similarly, anxiety and sensitized fear were also intensified. CFos expression levels in LH was higher in the PTSD group. Inhibition of Orx1R in the amygdala significantly decreased memory acquisition, diminished anxiety, and decreased the sensitized fear in the SB group. Applying SB to the amygdala after each fear memory test significantly decreased freezing. Expression of Orx1R was significantly higher following fear conditioning. These results indicate a likely involvement of the orexin and amygdalar Orx1R in memory acquisition and in extinction of PTSD.
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Tonsila do Cerebelo/metabolismo , Extinção Psicológica/fisiologia , Memória/fisiologia , Receptores de Orexina/metabolismo , Transtornos de Estresse Pós-Traumáticos/metabolismo , Tonsila do Cerebelo/efeitos dos fármacos , Animais , Ansiedade/genética , Ansiedade/metabolismo , Comportamento Animal , Benzoxazóis/farmacologia , Modelos Animais de Doenças , Teste de Labirinto em Cruz Elevado , Medo , Reação de Congelamento Cataléptica , Hipotálamo/efeitos dos fármacos , Hipotálamo/metabolismo , Naftiridinas/farmacologia , Teste de Campo Aberto , Antagonistas dos Receptores de Orexina/farmacologia , Receptores de Orexina/efeitos dos fármacos , Receptores de Orexina/genética , Orexinas/metabolismo , RNA Mensageiro , Ratos , Transtornos de Estresse Pós-Traumáticos/genética , Transtornos de Estresse Pós-Traumáticos/fisiopatologia , Ureia/análogos & derivados , Ureia/farmacologiaRESUMO
There is evidence that oxidative stress involves in homocysteine-induced pathogenesis. Considering the antioxidative properties of folic acid and its involvement as a cofactor for methionine synthase (MS) in the homocysteine-methionine cycle, the aim of this study was to evaluate the mechanism associated with homocysteine-induced toxicity and its prevention with folic acid supplementation. Male rat pups were divided into four groups including control, homocysteine (Hcy), Hcy + folic acid and folic acid groups. The Hcy group received Hcy 0.3-0.6 µmol/g body weight, while Hcy + folic acid group received folic acid orally as 0.011 µmol/g body weight along with Hcy on a postnatal day (PD) 4 until 25. The reduced and oxidized glutathione (GSH and GSSG) levels, GSH/GSSG ratio, protein carbonyl content, cystathionine ß synthase (CBS), and MS activities in the cerebellum were measured 25 days after birth. Levels of malondialdehyde (MDA), marker of lipid peroxidation were measured. Also, Bcl2, Bax, and caspase-3 expression levels were measured by real-time quantitative PCR. Furthermore, caspase-3 protein level assay was performed by the ELISA test. Results indicated that Hcy administration could promote both lipid and protein oxidation, which was associated with increased amounts of caspase-3 mRNA and protein levels and Bax mRNA expression level in this group. Cerebellar MS, CBS enzyme activity, GSH, GSSG, and GSH/GSH ratio did not change following Hcy administration. Folic acid significantly reduced MDA level, protein carbonyl content, Bax, the caspase-3 mRNA, and protein expression levels in the cerebellum of Hcy-treated group. Moreover, cerebellar MS, CBS enzyme activity, GSH, and GSH/GSH ratio increased following folic acid treatment. We conclude that Hcy might cause apoptosis in the cerebellum. We suggest that folic acid, in addition of having antioxidant properties, can protect cerebellum against homocysteine-mediated neurotoxicity via modulating the expression of proteins that are contributed in regulation of apoptosis in the rat's cerebellum.
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Antioxidantes/administração & dosagem , Proteínas Reguladoras de Apoptose/metabolismo , Cerebelo/efeitos dos fármacos , Cerebelo/metabolismo , Ácido Fólico/administração & dosagem , Homocisteína/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Animais , Proteínas Reguladoras de Apoptose/genética , Caspase 3/metabolismo , Feminino , Masculino , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Ratos Wistar , Proteína X Associada a bcl-2/metabolismoRESUMO
OBJECTIVE: The unfavorable effects of electromagnetic radiation (EMR) emitted by the cell phone on reproduction health are controversial. Metalloproteinases play a vital role in ovarian follicle development. This study was designed to investigate the effects of exposure to the cell phone on the gelatinolytic activity of in vitro cultured mouse pre-antral follicle. MATERIALS AND METHODS: In this experimental study, pre-antral follicles were isolated from ovaries of immature mice (n=16) and cultured with or without exposure to the cell phone in talking mode for 60 minutes. The gelatinolytic activity was evaluated through the zymography method, as well as the gene expression of matrix metalloproteinases (MMPs) namely MMP-2 and -9 and tissue inhibitors of metalloproteinases (TIMPs) namely, TIMP-1 and -2 by the real-time polymerase chain reaction (PCR) method. Also, in parallel, the development of pre-antral follicles was assessed. RESULTS: The maturation parameters of the cell phone-exposed pre-antral follicles were significantly lower compared with the control group (P<0.05). The gelatinolytic activity was significantly decreased in the cell phone-exposed preantral follicles compared with the control group (P<0.05). The relative mRNA expression of the MMP-2 gene was significantly (P<0.05) increased in the cell phone-exposed pre-antral follicles whereas the expression rate of the MMP-9 gene was considerably (P<0.05) reduced when compared with the control group. Conversely, the relative expression of the TIMP-1 was markedly (P<0.05) increased in the cell phone-exposed pre-antral follicles while the expression of the TIMP-2 was (P<0.05) significantly diminished in comparison with the control group. CONCLUSION: Exposure to the cell phone alters the growth and maturation rate of murine ovarian follicle through the changing in the expression of the MMP-2 and -9 genes, as well as the gelatinolytic activity.
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BACKGROUND: Radiations emitting from mobile phones have been proposed to affect people's health, mediated by various mechanisms like induction of oxidative stress. OBJECTIVE: This study aims to investigate the effect of cell phone exposure on the oxidative status of mice preantral follicles (PFs) during in vitro culture. MATERIALS AND METHODS: PFs (nâ=â2580) were isolated mechanically from 16 to 18 day-old NMRI mice (nâ=â50) and divided into control and cell phone-exposed groups. PFs were cultured for 12 days and ovulation was induced using human chorion gonadotropin. The developmental parameters including size, survival, antral cavity formation, ovulation and oocyte maturation were assessed. In parallel, enzymatic antioxidants activities, total antioxidant capacity (TAC), and Malondialdehyde (MDA) levels were evaluated. RESULTS: The diameters and the rates of survival, antrum formation, ovulation, and metaphase II oocytes of exposed PFs to cell phone were significantly lower than those of the control group (pâ≤â0.001). The PFs exposed to cell phone had significantly lower superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase (CAT) activity compared with the control group. In the cell phone exposed PFs, the TAC level was significantly lower (pâ≤â0.001) and MDA levels was significantly higher (pâ≤â0.001), compared tothe those of control group. CONCLUSION: Exposure to cell phone compromised the developmental competence of mice PFs by increasing oxidative stress.
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AIM: The early life stress has significant long-term effects on the development of the offspring. This study was undertaken to verify if maternal separation as a stressor agent affects the oxidative status and developmental competence of mouse pre-antral follicles (PF) during in vitro culture period. METHODS: Female litters of National Medical Research Institute mice were divided into two groups: maternally separated group (MS), separated from the mothers for 6 h per day from postnatal days 2-16; and the rest considered as the control group, which left undisturbed over the 14 days. The litters were sacrificed and the ovarian tissue was harvested to isolate the PF. The PF were in vitro cultured up to 12th day when ovulation was induced. The developmental parameters and oxidative status (i.e., total antioxidant capacity and Malondialdehyde levels, as well as the activities of superoxide dismutase, glutathione peroxidase and catalase) were assessed. RESULTS: The rates of survival, antrum formation, ovulation and oocyte maturation of PF derived from the MS group were significantly lower compared with those of the control group. Furthermore, the Malondialdehyde level of the MS group was significantly higher than that of the control group. By contrast, the total antioxidant capacity level was lower in the MS group with respect to the control group. Also, the activity of superoxide dismutase, glutathione peroxidase and catalase of PF, derived from the MS group, was significantly lower compared with those of the control group. CONCLUSION: Early life stress damages the developmental competence of mouse PF through induction of oxidative stress.
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Privação Materna , Folículo Ovariano , Estresse Oxidativo , Estresse Psicológico , Animais , Modelos Animais de Doenças , Feminino , Camundongos , Folículo Ovariano/metabolismo , Folículo Ovariano/fisiopatologia , Estresse Psicológico/metabolismoRESUMO
Stress as a homeostatic challenge leads to the malfunction of learning and memory processes, namely social learning and memory. The orexin system is involved in stress responses through connections to the hypothalamic-pituitary axis (HPA). In addition, the hippocampus, a structure vulnerable to stress-induced changes, expresses orexin receptors 1 and 2 (OXr1 and OXr2) in various sub-regions. The present study is aimed at assessing the effects of hippocampal orexin receptor blockade on social learning and memory impairments and anxiety development following stress. Male Wistar rats (220-250â¯g) underwent cannula implantation in the hippocampus. Acute (two mild electric shocks, 5.5â¯mA) and chronic stresses (ten days of restraint, 6â¯h daily) were applied with or without injection of orexin receptor antagonists (SB-334867 or TCS OX 29). Sociability and social novelty in animals were assessed in a three-chamber social maze at the end of stress application. Anxiety and exploratory behavior of animals were then examined, with 20â¯min intervals, using the open field (OF) and elevated plus maze (EPM) tests, respectively. Cisterna Magna cerebro-spinal fluid (CSF) was drained, before sacrifice, for orexin (OX) assay and trunk blood was collected to measure the plasma corticosterone (CRT). Neither the acute nor the chronic stress could affect the sociability. The acute but not chronic stress prevented the animal from sniffing the familiar caged rat in the novelty session, a response which was reversed following the blockade of both OXRs. Furthermore, acute but not chronic stress, led to increased anxiety and immobility behavior which were both impeded by blocking the orexin receptor (OXR). Conversely, OX content in CSF increased due to chronic restraint stress, an effect that was reversed by orexin blockade. Finally, elevated plasma CRT was recorded in response to both acute and chronic stresses. The observed increase in plasma CRT in chronically-stressed rats was abolished following inhibition of OXRs, however a similar effect was not seen in the acute-stress group. Our results identify hippocampal OXRs as potential candidates capable of preventing acute stress-induced impairments of social novelty and anxiety behavior, and chronic stress-induced plasma CRT and CSF orexin, changes. OXR manipulation may improve adaptation to stress pathophysiology.
Assuntos
Aprendizagem em Labirinto/fisiologia , Memória/fisiologia , Receptores de Orexina/fisiologia , Comportamento Social , Estresse Psicológico/fisiopatologia , Animais , Ansiedade/fisiopatologia , Benzoxazóis/administração & dosagem , Hipocampo/efeitos dos fármacos , Hipocampo/fisiologia , Isoquinolinas/administração & dosagem , Masculino , Naftiridinas , Antagonistas dos Receptores de Orexina/administração & dosagem , Piridinas/administração & dosagem , Ratos Wistar , Estresse Psicológico/prevenção & controle , Ureia/administração & dosagem , Ureia/análogos & derivadosRESUMO
A widely held view suggests that homocysteine (Hcy) can contribute to neurodegeneration through promotion of oxidative stress. There is evidence that homocysteine is toxic to cerebellar Purkinje neurons in vitro; however, in vivo action of Hcy on Purkinje cell has not been investigated so far. Thus, this study was designed to evaluate the Hcy effects on neonatal rat cerebellum and cerebellar oxidative stress. We also evaluated the folic acid effects on biochemical alterations elicited by hyperhomocysteinemia (hHcy) in the cerebellum. Group I received normal saline, group II received Hcy subcutaneously twice a day at 8-h intervals (0.3-0.6 µmol/g body weight), group III received Hcy + folic acid (0.011 µmol/g body weight), and group IV received folic acid on postnatal day (PD) 4 until 25. On day 25, superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities in the cerebellum and motor cortex were assayed. Malondialdehyde (MDA) levels were also evaluated as a marker of lipid peroxidation. Rotarod and locomotor activity tests were performed in PD 25-27. Our results indicated that administration of Hcy increased plasma, cortical, and cerebellar total Hcy levels; reduced GPx activity; and induced lipid peroxidation in the cerebellum. Hcy impaired performance on the rotarod in rats. However, treatment with folic acid significantly attenuated motor coordination impairment, GPx activity reduction, the lipid peroxidation process, and significantly reduced plasma total Hcy levels. Histological analysis indicated that Hcy could decrease Purkinje cell count and folic acid prevented this toxic effect. We conclude that Hcy can induce neurotoxicity and folic acid has neuroprotective effects against cerebellar Hcy toxicity.
Assuntos
Cerebelo/efeitos dos fármacos , Cerebelo/crescimento & desenvolvimento , Ácido Fólico/farmacologia , Homocisteína/efeitos adversos , Fármacos Neuroprotetores/farmacologia , Animais , Antioxidantes/farmacologia , Doenças Cerebelares/induzido quimicamente , Doenças Cerebelares/tratamento farmacológico , Doenças Cerebelares/metabolismo , Doenças Cerebelares/patologia , Cerebelo/metabolismo , Cerebelo/patologia , Ácido Fólico/sangue , Homocisteína/sangue , Peroxidação de Lipídeos/efeitos dos fármacos , Peroxidação de Lipídeos/fisiologia , Masculino , Córtex Motor/efeitos dos fármacos , Córtex Motor/crescimento & desenvolvimento , Córtex Motor/metabolismo , Córtex Motor/patologia , Doenças Neurodegenerativas/induzido quimicamente , Doenças Neurodegenerativas/tratamento farmacológico , Doenças Neurodegenerativas/metabolismo , Doenças Neurodegenerativas/patologia , Fármacos Neuroprotetores/sangue , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Distribuição Aleatória , Ratos WistarRESUMO
BACKGROUND: The Wingless-type (Wnt)/ß-catenin signaling pathway controls cell homeostasis. Reproductive tissues are dynamic in response to steroidal hormone changes. Steroidal hormones are known to control the Wnt/ß-catenin pathway, but their role in reproductive tissues remains unknown. OBJECTIVE: The present study aims to investigate the expression patterns of Wnt/ß-catenin target genes in mouse reproductive tissues during the normal estrous cycle. MATERIALS AND METHODS: In this experimental study, 16 adult NMRI mice were grouped as proestrus, estrus, metestrus, and diestrus according to vaginal smear and histological evaluation of uterine and ovarian tissues. Uterine horns and ovarian tissues were collected. Reverse transcription quantitative polymerase chain reaction was performed to evaluate the expression of Wnt/ß-catenin target genes (Myc2, Ppard, Id2, Birc5, and Ascl2) at different stages of the estrous cycle. RESULTS: The expression levels of Id2, Ascl2, and Pprd in uterine tissue were significantly higher at the proestrus phase than at the other stages. Meanwhile, Birc5 expression in uterine tissue was significantly higher at the metestrus stage than at the other stages. Furthermore, Myc2 expression was significantly higher at the diestrus stage than at the estrus and metestrus stages. In the ovarian tissue, the highest expression of Id2, Ascl2, and Birc5 was detected at the proestrus stage, whereas the highest expression of Myc2 and Ppard was observed at the estrus stage. CONCLUSION: This study showed that Wnt/ß-catenin target genes profiles are different among estrous cycle. It seems that different hormonal profiles during estrous cycles play a key role in the expression pattern of Wnt/ß-catenin target genes in ovarian and uterine tissue.
RESUMO
OBJECTIVES: Seizures are epileptic manifestations that are intrinsically modulated through different neurotransmitters and receptor systems. Although glutamate increases excitation and hence seizures, it activates other systems which could potentially terminate seizures. Histamine originates from neurons of the posterior hypothalamus (PH) and can mediate anticonvulsant properties, but the effect of local PH glutamate on hippocampal histamine content is unknown. Therefore, in this study, the effect of PH glutamate and the involvement of hippocampal histamine in pentylenetetrazol (PTZ) induced seizure activity was studied. MATERIALS AND METHODS: OX2R antagonist (TCS OX2 29, 40nmol/1µl, intra-PH), AMPA/Kainate receptor antagonist (CNQX, 3mM, intra-PH) and glutamate (1mM) were injected bilaterally into PH using stereotaxic surgery. The intravenous PTZ infusion model was used to generate behavioral convulsions and the amount of hippocampal histamine content was then measured using a biochemical method. RESULTS: Administration of glutamate into PH decreased both seizure stage and the duration of tonic-clonic convulsion (TCC) with increasing TCC latency and hippocampal histamine content. Blocking OX2Rs alone or coinhibition of OX2Rs and AMPA/kainate receptors reversed these effects by increasing both seizure stage and TCC duration, and by decreasing both latency and consequent histamine content. CONCLUSIONS: Our findings suggest that glutamate administration into PH may control seizures (stages and duration) through increasing the hippocampal histamine content.