cytochrome-c-t and Memory-Disorders

Anesthesia and surgery can induce perioperative neurocognitive disorders (PND). Mitochondrial dysfunction has been proposed to be one of the earliest triggering events in surgery-induced neuronal damage. Dexmedetomidine has been demonstrated to attenuate the impairment of cognition in aged rats induced by surgery in our previous study.. Male Sprague-Dawley rats underwent hepatic apex resection under anesthesia with propofol to clinically mimic human abdominal surgery. The rats were divided into three groups: Control group, Model group and Dexmedetomidine (Dex) group. Cognitive function was evaluated with the Morris water maze (MWM), Open Field Test (OFT)and Novel object recognition task (NOR). Ultrastructural change in neuronal mitochondria was measured by transmission electron microscopy. Mitochondrial function was measured by mitochondrial membrane potential and activities of mitochondrial complexes. Neuronal morphology was observed with H&E staining and the activation of glial cells was observed by immunohistochemistry in the hippocampus. Protein levels were measured by Western blot (WB) and immunofluorescence at 3 and 7 days after surgery.. Surgery-induced cognitive decline lasts three days, but not seven days after surgery in the model group. Transmission electron microscope showed the mitochondrial structure damage in the model group, similar changes were not induced in the Dex group. Dexmedetomidine may reverse the decrease in mitochondrial membrane potential and mitochondrial complex activity. Compared with the Control group, the expression of cytochrome c was significantly increased in model group by Western blot and immunofluorescence on days 3, but not day 7. Rats from the Model group expressed significantly greater levels of Iba-1 and GFAP compared with the Control group and the Dex group.. Dexmedetomidine appears to reverse surgery-induced behavior, mitigate the higher density of Iba-1 and GFAP, reduce the damage of mitochondrial structure and function by alleviating oxidative stress and protect mitochondrial respiratory chain, thus increasing cytochrome c oxidase (COX) expression and downregulate the expression of cytochrome c protein in the hippocampus of rats.

Topics: Animals; Cytochromes c; Dexmedetomidine; Hippocampus; Humans; Male; Memory Disorders; Propofol; Rats; Rats, Sprague-Dawley; Spatial Memory

Anesthesia and surgery are associated with perioperative neurocognitive disorders (PND). Dexmedetomidine is known to improve PND in rats; however, little is known about the mechanisms. Male Sprague-Dawley rats were subjected to resection of the hepatic apex under propofol anesthesia to clinically mimic human abdominal surgery. The rats were divided into four groups: control group (C), anesthesia group (A), model group (M), and model + dex group (D). Cognitive function was evaluated with the Morris water maze (MWM). Neuronal morphology was observed with H&E staining, Nissl's staining and immunohistochemistry. Transcriptome analysis and quantitative real-time PCR were performed to investigate functional mitochondrial mRNA changes in the hippocampus. Protein levels were measured by Western blotting at 1, 3, and 7 days after surgery. Surgery-induced cognitive decline lasted for three days, but not seven days after surgery in the M group; however, rats in the D group were significantly improved by dexmedetomidine. No significant differences in the number of neurons were observed between the groups after surgery. Rats from the M group showed significantly greater expression levels of Iba-1 and GFAP compared with the C group and the D group. Rats in the M group demonstrated increased Surf1 and Cytochrome c expression on days 1 and 3, but not day 7; similar changes were not induced in rats in the D group. Dexmedetomidine appears to reverse surgery-induced behavior, mitigate the higher density of Iba-1 and GFAP, and downregulate the expression of Surf1 and Cytochrome c protein in the hippocampus of rats in a PND model.

Topics: Animals; Cytochromes c; Dexmedetomidine; Hippocampus; Male; Memory Disorders; Propofol; Rats; Rats, Sprague-Dawley

MDMA-induced impairments of memory performance have been reported in different human and animal studies. However, the correlation between spatial memory impairment, brain mitochondrial function, and concentrations of MDMA and its metabolites has not yet been investigated despite it being needed for comparison with human studies. Therefore, the aim of this study was to investigate the dose concentration and spatial memory as well as brain mitochondrial function association after MDMA administration in rats. We assessed the effects of MDMA [0.5, 2.5, 5, 10 and 15 mg/kg; intraperitoneally (I.P)] on spatial memory of male Wistar rats in the Morris water maze test (MWM) and brain mitochondrial function (i.e., reactive oxygen species, mitochondrial membrane potential, swelling and outer membrane damage, cytochrome c release, and ADP/ATP ratio). Concentrations of MDMA and its metabolite, MDA, were determined in plasma, cerebrospinal fluid (CSF) and brain which was obtained immediately after probe test of MWM (i.e., 4 h after last training trial). The results of this study indicate nonlinear kinetics of MDMA after I.P adminstration. Also, an insignificant correlation was observed between MDMA doses and the MDA/MDMA ratio in plasma, CSF, and brain. Moreover, the results showed that MDMA, but not MDA, accumulated in brain tissue by increasing the administered doses. Beside, MDMA-induced impairments of spatial memory and brain mitochondrial function were significantly correlated with the concentrations of both MDMA and MDA in plasma, CSF, and brain. Therefore, it can be suggested that MDMA and its metabolite, MDA, affect spatial memory and brain mitochondrial function.

Topics: Animals; Brain; Cognition; Cytochromes c; Dose-Response Relationship, Drug; Hallucinogens; Humans; Male; Maze Learning; Membrane Potential, Mitochondrial; Memory Disorders; Mitochondria; N-Methyl-3,4-methylenedioxyamphetamine; Rats; Rats, Wistar; Reactive Oxygen Species; Serotonin; Spatial Memory

The aim of this study was to investigate the combination effect of exercise training and eugenol supplementation on the hippocampus apoptosis induced by CPF. 64 adult male albino rats were randomly selected and devided into eight groups of eight including: control, exercise (EXE), chlorpyrifos (CPF), Control + Oil (Co + Oil), Control + DMSO (Co + DMSO), chlorpyrifos + eugenol (CPF + Sup), chlorpyrifos + exercise (CPF + Exe) and, chlorpyrifos + exercise + eugenol (CPF + Exe + Eu). Four experimental groups received intraperitoneal injection (5 days a week) of 3.0 mg/kg body weight CPF in DMSO for 6 consecutive weeks. The exercise groups performed aerobic 5 days per week over 4 weeks. Eugenol were administered by gavage. Finally, the animals were sacrificed using CO

Topics: Acetylcholinesterase; Adenosine Triphosphate; Animals; Apoptosis; Avoidance Learning; Brain-Derived Neurotrophic Factor; Caspase 3; Chlorpyrifos; Combined Modality Therapy; Cytochromes c; Disease Models, Animal; Eugenol; Exercise Therapy; Hippocampus; Male; Memory Disorders; Nerve Tissue Proteins; Organophosphate Poisoning; Physical Conditioning, Animal; Random Allocation; Rats; Rats, Wistar

As a general anesthesia drug, sevoflurane has been found to be potentially neurotoxic to the developing brain. Neuroglobin (Ngb) is a novel oxygen-carrying globulin that has been demonstrated to have neuroprotective effects in a variety of central nervous system disorders. However, it is unclear whether Ngb has a protective effect on nerve damage caused by sevoflurane. Therefore, this study was designed to investigate the effect and related mechanisms of Ngb on neural injury induced by sevoflurane. Pregnant rats on gestational day 20 (G20) were exposed to 3.5% sevoflurane for two hours, which led to an increase of Ngb on the 0-1st day after birth and decreased significantly on the 3rd day, while Cytochrome c increased from the 1 st day until the 7th day of offspring rats. Meanwhile, sevoflurane reduced Bcl-2 and Hif-1αand increased Bax and cleaved-caspase 3 in the third day after birth. Hemin inhibits endogenous apoptosis by increasing Ngb and Hif-1α. And increased Ngb improved the damage of long-term learning and memory induced by sevoflurane and increased the number of neurons in the hippocampus. We concluded that Ngb can improve the neuronal injury induced by sevoflurane exposure by inhibiting apoptosis and increasing the number of neurons. And this protective effect of Ngb may be related to Hif-1α signaling pathway. This finding may provide a novel therapeutic approach for sevoflurane -induced nerve damage.

Topics: Anesthetics, Inhalation; Animals; Apoptosis; Brain; Brain Chemistry; Cytochromes c; Female; Hemin; Hypoxia-Inducible Factor 1, alpha Subunit; Learning; Memory Disorders; Neuroglobin; Neurons; Neuroprotective Agents; Pregnancy; Prenatal Exposure Delayed Effects; Rats; Sevoflurane; Signal Transduction

Oxidative stress has been implicated in the pathogenesis of neurodegenerative disorders, such as vascular cognitive impairment (VCI). The present study was performed to investigate the potential neuroprotective effect of the antioxidant astaxanthin (ATX) in a mouse model of VCI. VCI was induced in male ICR mice by repeated occlusion of the bilateral common carotid artery, leading to repeated cerebral ischemia/reperfusion (IR) injury. After surgery, the mice received ATX or an equal volume of vehicle by daily intragastric administration for 28days. The results showed that ATX treatment ameliorated learning and memory deficits after repeated cerebral IR. ATX administration rescued the number of surviving pyramidal neurons in the CA1 and CA3 regions. The concentration of malondialdehyde was decreased, and the levels of reduced glutathione and superoxide dismutase in the hippocampus were increased. Electron microphotography revealed that damage to the ultrastructure of neurons was also reduced by ATX administration. In addition, the expression levels of Cytochrome C (Cyt C), cleaved Caspase-3 and Bax were lower and the expression of Bcl-2 was higher compared to control IR mice. Our findings demonstrate that ATX is able to suppresse learning and memory impairment caused by repeated cerebral IR and that this effect is associated with attenuation of oxidative stress.

Topics: Animals; Antioxidants; Apoptosis; Brain Ischemia; Cytochromes c; Dementia, Vascular; Disease Models, Animal; Glutathione; Hippocampus; Learning; Male; Malondialdehyde; Maze Learning; Memory Disorders; Mice; Mice, Inbred ICR; Neurons; Neuroprotective Agents; Oxidative Stress; Reperfusion; Reperfusion Injury; Superoxide Dismutase; Xanthophylls

Oxidative stress and mitochondrial dysfunction play indispensable role in memory and learning impairment. Growing evidences have shed light on anti-oxidative role for melatonin in memory deficit. We have previously reported that inhibition of protein kinase A by H-89 can induce memory impairment. Here, we investigated the effect of melatonin on H-89 induced spatial memory deficit and pursued their interactive consequences on oxidative stress and mitochondrial function in Morris Water Maze model. Rats received melatonin (50 and 100μg/kg/side) and H-89(10μM) intra-hippocampally 30min before each day of training. Animals were trained for 4 consecutive days, each containing one block from four trials. Oxidative stress indices, including thiobarbituric acid (TBARS), reactive oxygen species (ROS), thiol groups, and ferric reducing antioxidant power (FRAP) were assessed using spectrophotometer. Mitochondrial function was evaluated through measuring ROS production, mitochondrial membrane potential (MMP), swelling, outer membrane damage, and cytochrome c release. As expected from our previous report, H-89 remarkably impaired memory by increasing the escape latency and traveled distance. Intriguingly, H-89 significantly augmented TBARS and ROS levels, caused mitochondrial ROS production, swelling, outer membrane damage, and cytochrome c release. Moreover, H-89 lowered thiol, FRAP, and MMP values. Intriguingly, melatonin pre-treatment not only effectively hampered H-89-mediated spatial memory deficit at both doses, but also reversed the H-89 effects on mitochondrial and biochemical indices upon higher dose. Collectively, these findings highlight a protective role for melatonin against H-89-induced memory impairment and indicate that melatonin may play a therapeutic role in the treatment of oxidative- related neurodegenerative disorders.

Topics: Animals; Antioxidants; Cytochromes c; Disease Models, Animal; Escape Reaction; Hippocampus; Hypnotics and Sedatives; Isoquinolines; Lipid Peroxidation; Male; Melatonin; Membrane Potential, Mitochondrial; Memory Disorders; Mitochondria; Protein Kinase Inhibitors; Rats; Rats, Wistar; Reaction Time; Reactive Oxygen Species; Sulfonamides; Xylazine

Amyloid-β, tau, and α-synuclein, or more specifically their soluble oligomers, are the aetiologic molecules in Alzheimer's disease, tauopathies, and α-synucleinopathies, respectively. These proteins have been shown to interact to accelerate each other's pathology. Clinical studies of amyloid-β-targeting therapies in Alzheimer's disease have revealed that the treatments after disease onset have little benefit on patient cognition. These findings prompted us to explore a preventive medicine which is orally available, has few adverse effects, and is effective at reducing neurotoxic oligomers with a broad spectrum. We initially tested five candidate compounds: rifampicin, curcumin, epigallocatechin-3-gallate, myricetin, and scyllo-inositol, in cells expressing amyloid precursor protein (APP) with the Osaka (E693Δ) mutation, which promotes amyloid-β oligomerization. Among these compounds, rifampicin, a well-known antibiotic, showed the strongest activities against the accumulation and toxicity (i.e. cytochrome c release from mitochondria) of intracellular amyloid-β oligomers. Under cell-free conditions, rifampicin inhibited oligomer formation of amyloid-β, tau, and α-synuclein, indicating its broad spectrum. The inhibitory effects of rifampicin against amyloid-β and tau oligomers were evaluated in APPOSK mice (amyloid-β oligomer model), Tg2576 mice (Alzheimer's disease model), and tau609 mice (tauopathy model). When orally administered to 17-month-old APPOSK mice at 0.5 and 1 mg/day for 1 month, rifampicin reduced the accumulation of amyloid-β oligomers as well as tau hyperphosphorylation, synapse loss, and microglial activation in a dose-dependent manner. In the Morris water maze, rifampicin at 1 mg/day improved memory of the mice to a level similar to that in non-transgenic littermates. Rifampicin also inhibited cytochrome c release from the mitochondria and caspase 3 activation in the hippocampus. In 13-month-old Tg2576 mice, oral rifampicin at 0.5 mg/day for 1 month decreased amyloid-β oligomer accumulation, tau hyperphosphorylation, synapse loss, and microglial activation, but not amyloid deposition. Rifampicin treatment to 14-15-month-old tau609 mice at 0.5 and 1 mg/day for 1 month also reduced tau oligomer accumulation, tau hyperphosphorylation, synapse loss, and microglial activation in a dose-dependent fashion, and improved the memory almost completely at 1 mg/day. In addition, rifampicin decreased the level of p62/sequestosome-1 in the brain without

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Caspase 3; Cells, Cultured; Cytochromes c; Dose-Response Relationship, Drug; Female; Hippocampus; Maze Learning; Memory Disorders; Mice; Mice, Transgenic; Microglia; Microtubule-Associated Proteins; Neuroprotective Agents; Phosphorylation; Rifampin; Sequestosome-1 Protein; Synapses; Synucleins; tau Proteins; Tauopathies

Providing adequate protection against cerebral ischemia remains an unrealized goal. The present study was aimed at testing whether chronic intermittent hypobaric hypoxia (CIHH) would have protective effects against cerebral ischemia and investigating the potential role of mitochondrial membrane ATP-sensitive potassium channel (mitoK. Ischemia was induced in rats by occlusion of bilateral common carotid arteries for 8min on day 2 after bilateral vertebral arteries were permanently electrocauterized and CIHH was simulated in a hypoxic chamber. Learning and memory impairments were analyzed using the Morris water maze. The delay neuronal death (DND) in the hippocampus CA1 was observed by thionine staining. The expression of the two subunits of mitoK. CIHH pretreatment ameliorated the learning and memory impairments produced by ischemia, concomitant with reduced DND in the hippocampus CA1 area. Expression levels of SUR1 and Kir6.2 both increased for at least one week after CIHH pretreatment. Levels of the two subunits were higher in the CIHH pretreatment combined with ischemia group than the ischemia only group at 2 d and 7 d after ischemia. Furthermore, the concentration of Cyt c was decreased in mitochondria and increased in the cytoplasm after ischemia which was prevented by CIHH. The decrease of Δψm and the destruction of mitochondrial ultrastructure were both rescued by CIHH pretreatment. The above protective effects of CIHH were blocked by 5-HD intraperitoneal injection 30min before ischemia.. CIHH pretreatment can reduce cerebral ischemic injury, which is mediated by upregulating the expression and activity of mitoK

Topics: Animals; Brain Ischemia; CA1 Region, Hippocampal; Cytochromes c; Hypoxia; Male; Maze Learning; Membrane Potential, Mitochondrial; Memory Disorders; Mitochondria; Potassium Channels; Potassium Channels, Inwardly Rectifying; Pressure; Pyramidal Cells; Rats, Wistar; Spatial Memory; Sulfonylurea Receptors

The accumulation and deposition of β-amyloid peptide (Aβ) in senile plaques and cerebral vasculature is believed to facilitate the progressive neurodegeneration that occurs in the Alzheimer's disease (AD). The present study sought to elucidate possible effects of baicalin, a natural phytochemical, on Aβ toxicity in a rat model of AD. By morris water maze test, Aβ1-42 injection was found to cause learning and memory deficit in rat, which was effectively improved by baicalin treatment. Besides, histological examination showed that baicalin could attenuate the hippocampus injury caused by Aβ. The neurotoxicity mechanism of Aβ is associated with oxidative stress and apoptosis, as revealed by increased malonaldehyde generation and TUNEL-positive cells. Baicalin treatment was able to increase antioxidant capabilities by recovering activities of antioxidant enzymes (superoxide dismutase, catalase, and glutathione peroxidase) and up-regulating their gene expression. Moreover, baicalin effectively prevented Aβ-induced mitochondrial membrane potential decrease, Bax/Bcl-2 ratio increase, cytochrome c release, and caspase-9/-3 activation. In addition, we found that the anti-oxidative effect of baicalin was associated with Nrf2 activation. In conclusion, baicalin effectively improved Aβ-induced learning and memory deficit, hippocampus injury, and neuron apoptosis, making it a promising drug to preventive interventions for AD.

Topics: Amyloid beta-Peptides; Animals; Antioxidants; Apoptosis; bcl-2-Associated X Protein; Caspases; Cell Nucleus; Cytochromes c; Enzyme Activation; Flavonoids; Hippocampus; Male; Malondialdehyde; Membrane Potential, Mitochondrial; Memory Disorders; Neuroprotective Agents; NF-E2-Related Factor 2; Oxidative Stress; Rats, Wistar; Real-Time Polymerase Chain Reaction

NF-κB upregulation has been demonstrated in neurons and glial cells in response to experimental injury and neuropathological disorders, where it has been related to both neurodegenerative and neuroprotective activities. It has been generally recognized that NF-κB plays important roles in the regulation of apoptosis and inflammation as well as innate and adaptive immunity. However, the regulatory mechanism of NF-κB in apoptosis remained to be determined. The present study sought to first investigate the effect of a NF-κB inhibitor SN50, which inhibits NF-κB nuclear translocation, on cell death and behavioral deficits in our mice traumatic brain injury (TBI) models. Additionally, we tried to elucidate the possible mechanisms of the therapeutic effect of SN50 through NF-κB regulating apoptotic and inflammatory pathway in vivo. Encouragingly, the results showed that pretreatment with SN50 remarkably attenuated TBI-induced cell death (detected by PI labeling), cumulative loss of cells (detected by lesion volume), and motor and cognitive dysfunction (detected by motor test and Morris water maze). To analyze the mechanism of SN50 on cell apoptotic and inflammatory signaling pathway, we thus assessed expression levels of TNF-α, cathepsin B and caspase-3, Bid cleavage and cytochrome c release in SN50-pretreated groups compared with those in saline vehicle groups. The results imply that through NF-κB/TNF-α/cathepsin networks SN50 may contribute to TBI-induced extrinsic and intrinsic apoptosis, and inflammatory pathways, which partly determined the fate of injured cells in our TBI model.

Topics: Animals; BH3 Interacting Domain Death Agonist Protein; Brain; Brain Injuries; Caspase 3; Cathepsin B; Cytochromes c; Cytosol; Disease Models, Animal; Enzyme Inhibitors; Gene Expression Regulation; Male; Maze Learning; Memory Disorders; Mice; Mitochondria; Movement Disorders; Neurons; NF-kappa B; Peptides; Propidium; Signal Transduction; Time Factors

Alzheimer's disease (AD) is an irreversible, progressive brain disorder of the elderly characterized by learning and memory impairment. Stress level glucocorticoids (GCs) and β-amyloid (Aβ) peptides deposition are found to be correlated with dementia progression in patients with AD. However, little is known about the simultaneous effects of glucocorticoids and Aβ on learning and memory impairment and its mechanism. In this study, 12-month-old male rats were chronically treated with Aβ(25-35) (10 μg/rat, hippocampal CA1 injection) and dexamethasone (DEX, 1.5mg/kg) for 14 days to investigate the effects of DEX and Aβ(25-35) treatment on learning and memory impairments, pathological changes, neuronal ultrastructure, amyloid precursor protein (APP) processing and neuronal cell apoptosis. Our results showed that DEX or Aβ(25-35) treatment alone for 14 days had caused slight damage on learning and memory impairments and hippocampal neurons, but damages were significantly increased with DEX+Aβ(25-35) treatment. And the mRNA levels of the APP, β-secretase and caspase 3 were significantly increased after DEX+Aβ(25-35) treatment. The immunohistochemistry demonstrated that APP, Aβ(1-40), caspase 3 and cytochrome c in hippocampus CA1 were significantly increased. Furthermore, Hoechst 33258 staining and Aβ(1-40) ELISA results showed that DEX+Aβ(25-35) treatment induced hippocampus CA1 neuron apoptosis and increased the level of Aβ(1-40). The results suggest that the simultaneous effects of GCs and Aβ may have important roles in the etiopathogenesis of AD, and demonstrate that stressful life events and GC therapy may increase the toxicity of Aβ and have cumulative impacts on the course of AD development and progression.

Topics: Amyloid beta-Peptides; Amyloid beta-Protein Precursor; Amyloid Precursor Protein Secretases; Analysis of Variance; Animals; Apoptosis; Arabidopsis Proteins; Caspase 3; Cytochromes c; Dexamethasone; Disease Models, Animal; Drug Synergism; Enzyme-Linked Immunosorbent Assay; Gene Expression Regulation; Glucocorticoids; Hippocampus; Intramolecular Transferases; Learning Disabilities; Male; Maze Learning; Memory Disorders; Microscopy, Electron, Scanning; Neurons; Peptide Fragments; Rats; Rats, Sprague-Dawley; Time Factors