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Sample records for acute neuronal damage

  1. NRF2 promotes neuronal survival in neurodegeneration and acute nerve damage

    PubMed Central

    Xiong, Wenjun; MacColl Garfinkel, Alexandra E.; Li, Yiqing; Benowitz, Larry I.; Cepko, Constance L.

    2015-01-01

    Oxidative stress contributes to the loss of neurons in many disease conditions as well as during normal aging; however, small-molecule agents that reduce oxidation have not been successful in preventing neurodegeneration. Moreover, even if an efficacious systemic reduction of reactive oxygen and/or nitrogen species (ROS/NOS) could be achieved, detrimental side effects are likely, as these molecules regulate normal physiological processes. A more effective and targeted approach might be to augment the endogenous antioxidant defense mechanism only in the cells that suffer from oxidation. Here, we created several adeno-associated virus (AAV) vectors to deliver genes that combat oxidation. These vectors encode the transcription factors NRF2 and/or PGC1a, which regulate hundreds of genes that combat oxidation and other forms of stress, or enzymes such as superoxide dismutase 2 (SOD2) and catalase, which directly detoxify ROS. We tested the effectiveness of this approach in 3 models of photoreceptor degeneration and in a nerve crush model. AAV-mediated delivery of NRF2 was more effective than SOD2 and catalase, while expression of PGC1a accelerated photoreceptor death. Since the NRF2-mediated neuroprotective effects extended to photoreceptors and retinal ganglion cells, which are 2 very different types of neurons, these results suggest that this targeted approach may be broadly applicable to many diseases in which cells suffer from oxidative damage. PMID:25798616

  2. NAAG peptidase inhibitor reduces acute neuronal degeneration and astrocyte damage following lateral fluid percussion TBI in rats.

    PubMed

    Zhong, Chunlong; Zhao, Xueren; Sarva, Jayaprakash; Kozikowski, Alan; Neale, Joseph H; Lyeth, Bruce G

    2005-02-01

    Traumatic brain injury (TBI) produces a rapid and excessive elevation in extracellular glutamate associated with excitotoxicity and secondary brain pathology. The peptide neurotransmitter Nacetylaspartylglutamate (NAAG) suppresses glutamate transmission through selective activation of presynaptic Group II metabotropic glutamate receptor subtype 3 (mGluR3). Thus, inhibition of NAAG peptidase activity and the prolong presence of synaptic NAAG were hypothesized to have significant potential for cellular protection following TBI. In the present study, a novel NAAG peptidase inhibitor, ZJ-43, was used in four different doses (0, 50, 100, or 150 mg/kg). Each dose was repeatedly administered i.p. (n=5/group) by multiple injections at three times (0 time, 8 h, 16 h) after moderate lateral fluid percussion TBI in the rat. An additional group was co-administered ZJ-43 (150 mg/kg) and the Group II mGluR antagonist, LY341495 (1 mg/kg), which was predicted to abolish any protective effects of ZJ-43. Rats were euthanized at 24 h after TBI, and brains were processed with a selective marker for degenerating neurons (Fluoro-Jade B) and a marker for astrocytes (GFAP). Ipsilateral neuronal degeneration and bilateral astrocyte loss in the CA2/3 regions of the hippocampus were quantified using stereological techniques. Compared with vehicle, ZJ-43 significantly reduced the number of the ipsilateral degenerating neurons (p<0.01) with the greatest neuroprotection at the 50 mg/kg dose. Moreover, LY341495 successfully abolished the protective effects of ZJ-43. 50 mg/kg of ZJ-43 also significantly reduced the ipsilateral astrocyte loss (p<0.05). We conclude that the NAAG peptidase inhibitor ZJ-43 is a potential novel strategy to reduce both neuronal and astrocyte damage associated with the glutamate excitotoxicity after TBI. PMID:15716632

  3. Acute lower motor neuron tetraparesis.

    PubMed

    Añor, Sònia

    2014-11-01

    Flaccid nonambulatory tetraparesis or tetraplegia is an infrequent neurologic presentation; it is characteristic of neuromuscular disease (lower motor neuron [LMN] disease) rather than spinal cord disease. Paresis beginning in the pelvic limbs and progressing to the thoracic limbs resulting in flaccid tetraparesis or tetraplegia within 24 to 72 hours is a common presentation of peripheral nerve or neuromuscular junction disease. Complete body flaccidity develops with severe decrease or complete loss of spinal reflexes in pelvic and thoracic limbs. Animals with acute generalized LMN tetraparesis commonly show severe motor dysfunction in all limbs and severe generalized weakness in all muscles. PMID:25441630

  4. Soman increases neuronal COX-2 levels: possible link between seizures and protracted neuronal damage.

    PubMed

    Angoa-Pérez, Mariana; Kreipke, Christian W; Thomas, David M; Van Shura, Kerry E; Lyman, Megan; McDonough, John H; Kuhn, Donald M

    2010-12-01

    Nerve agent-induced seizures cause neuronal damage in brain limbic and cortical circuits leading to persistent behavioral and cognitive deficits. Without aggressive anticholinergic and benzodiazepine therapy, seizures can be prolonged and neuronal damage progresses for extended periods of time. The objective of this study was to determine the effects of the nerve agent soman on expression of cyclooxygenase-2 (COX-2), the initial enzyme in the biosynthetic pathway of the proinflammatory prostaglandins and a factor that has been implicated in seizure initiation and propagation. Rats were exposed to a toxic dose of soman and scored behaviorally for seizure intensity. Expression of COX-2 was determined throughout brain from 4h to 7 days after exposure by immunohistochemistry and immunoblotting. Microglial activation and astrogliosis were assessed microscopically over the same time-course. Soman increased COX-2 expression in brain regions known to be damaged by nerve agents (e.g., hippocampus, amygdala, piriform cortex and thalamus). COX-2 expression was induced in neurons, and not in microglia or astrocytes, and remained elevated through 7 days. The magnitude of COX-2 induction was correlated with seizure intensity. COX-1 expression was not changed by soman. Increased expression of neuronal COX-2 by soman is a late-developing response relative to other signs of acute physiological distress caused by nerve agents. COX-2-mediated production of prostaglandins is a consequence of the seizure-induced neuronal damage, even after survival of the initial cholinergic crisis is assured. COX-2 inhibitors should be considered as adjunct therapy in nerve agent poisoning to minimize nerve agent-induced seizure activity. PMID:20600289

  5. Involvement of leukotrienes in acute gastric damage.

    PubMed

    Boughton-Smith, N K

    1989-01-01

    The leukotrienes have potent inflammatory actions which could be of importance in gastric mucosal integrity. In animals, LTC4 produces vasoconstriction in the gastric mucosa. Furthermore, acute gastric damage produced by ethanol is accompanied by marked increases in the mucosal formation of LTC4 and LTB4. Depending on the extent of protection, prostaglandins either have no effect or prevent the increases in leukotriene formation which accompany ethanol-induced damage. Various non-specific inhibitors of leukotriene synthesis prevent ethanol and indomethacin-induced damage to the gastric mucosa. However, a novel selective 5-lipoxygenase inhibitor (BW A4C) had no effect on these models of acute gastric damage at doses which completely inhibited gastric mucosal leukotriene synthesis. These studies cast doubt on the role of the leukotrienes in these models of acute gastric damage. However, the potent biological actions of the leukotrienes may be of importance in the pathogenesis of other forms of gastric damage, or as mediators of chronic gastric ulceration or inflammation. PMID:2657289

  6. INTRANUCLEAR MATRIX METALLOPROTEINASES PROMOTE DNA DAMAGE AND APOPTOSIS INDUCED BY OXYGEN–GLUCOSE DEPRIVATION IN NEURONS

    PubMed Central

    HILL, J. W.; PODDAR, R.; THOMPSON, J. F.; ROSENBERG, G. A.; YANG, Y.

    2016-01-01

    Degradation of the extracellular matrix by elevated matrix metalloproteinase (MMP) activity following ischemia/reperfusion is implicated in blood–brain barrier disruption and neuronal death. In contrast to their characterized extracellular roles, we previously reported that elevated intranuclear MMP-2 and -9 (gelatinase) activity degrades nuclear DNA repair proteins and promotes accumulation of oxidative DNA damage in neurons in rat brain at 3-h reperfusion after ischemic stroke. Here, we report that treatment with a broad-spectrum MMP inhibitor significantly reduced neuronal apoptosis in rat ischemic hemispheres at 48-h reperfusion after a 90-min middle cerebral artery occlusion (MCAO). Since extracellular gelatinases in brain tissue are known to be neurotoxic during acute stroke, the contribution of intranuclear MMP-2 and -9 activities in neurons to neuronal apoptosis has been unclear. To confirm and extend our in vivo observations, oxygen–glucose deprivation (OGD), an in vitro model of ischemia/reperfusion, was employed. Primary cortical neurons were subjected to 2-h OGD with reoxygenation. Increased intranuclear gelatinase activity was detected immediately after reoxygenation onset and was maximal at 24 h, while extracellular gelatinase levels remained unchanged. We detected elevated levels of both MMP-2 and -9 in neuronal nuclear extracts and gelatinase activity in neurons co-localized primarily with MMP-2. We found a marked decrease in PARP1, XRCC1, and OGG1, and decreased PARP1 activity. Pretreatment of neurons with selective MMP-2/9 inhibitor II significantly decreased gelatinase activity and downregulation of DNA repair enzymes, decreased accumulation of oxidative DNA damage, and promoted neuronal survival after OGD. Our results confirm the nuclear localization of gelatinases and their nuclear substrates observed in an animal stroke model, further supporting a novel role for intranuclear gelatinase activity in an intrinsic apoptotic pathway in neurons

  7. Endogenous recovery after brain damage: molecular mechanisms that balance neuronal life/death fate.

    PubMed

    Tovar-y-Romo, Luis B; Penagos-Puig, Andrés; Ramírez-Jarquín, Josué O

    2016-01-01

    Neuronal survival depends on multiple factors that comprise a well-fueled energy metabolism, trophic input, clearance of toxic substances, appropriate redox environment, integrity of blood-brain barrier, suppression of programmed cell death pathways and cell cycle arrest. Disturbances of brain homeostasis lead to acute or chronic alterations that might ultimately cause neuronal death with consequent impairment of neurological function. Although we understand most of these processes well when they occur independently from one another, we still lack a clear grasp of the concerted cellular and molecular mechanisms activated upon neuronal damage that intervene in protecting damaged neurons from death. In this review, we summarize a handful of endogenously activated mechanisms that balance molecular cues so as to determine whether neurons recover from injury or die. We center our discussion on mechanisms that have been identified to participate in stroke, although we consider different scenarios of chronic neurodegeneration as well. We discuss two central processes that are involved in endogenous repair and that, when not regulated, could lead to tissue damage, namely, trophic support and neuroinflammation. We emphasize the need to construct integrated models of neuronal degeneration and survival that, in the end, converge in neuronal fate after injury. Under neurodegenerative conditions, endogenously activated mechanisms balance out molecular cues that determine whether neurons contend toxicity or die. Many processes involved in endogenous repair may as well lead to tissue damage depending on the strength of stimuli. Signaling mediated by trophic factors and neuroinflammation are examples of these processes as they regulate different mechanisms that mediate neuronal demise including necrosis, apoptosis, necroptosis, pyroptosis and autophagy. In this review, we discuss recent findings on balanced regulation and their involvement in neuronal death. PMID:26376102

  8. The Involvement of Secondary Neuronal Damage in the Development of Neuropsychiatric Disorders Following Brain Insults

    PubMed Central

    Chen, Yun; Garcia, Gregory E.; Huang, Wei; Constantini, Shlomi

    2014-01-01

    Neuropsychiatric disorders are one of the leading causes of disability worldwide and affect the health of billions of people. Previous publications have demonstrated that neuropsychiatric disorders can cause histomorphological damage in particular regions of the brain. By using a clinical symptom-comparing approach, 55 neuropsychiatric signs or symptoms related usually to 14 types of acute and chronic brain insults were identified and categorized in the present study. Forty percent of the 55 neuropsychiatric signs and symptoms have been found to be commonly shared by the 14 brain insults. A meta-analysis supports existence of the same neuropsychiatric signs or symptoms in all brain insults. The results suggest that neuronal damage might be occurring in the same or similar regions or structures of the brain. Neuronal cell death, neural loss, and axonal degeneration in some parts of the brain (the limbic system, basal ganglia system, brainstem, cerebellum, and cerebral cortex) might be the histomorphological basis that is responsible for the neuropsychiatric symptom clusters. These morphological alterations may be the result of secondary neuronal damage (a cascade of progressive neural injury and neuronal cell death that is triggered by the initial insult). Secondary neuronal damage causes neuronal cell death and neural injury in not only the initial injured site but also remote brain regions. It may be a major contributor to subsequent neuropsychiatric disorders following brain insults. PMID:24653712

  9. Neuronal uptake of serum albumin is associated with neuron damage during the development of epilepsy

    PubMed Central

    Liu, Zanhua; Liu, Jinjie; Wang, Suping; Liu, Sibo; Zhao, Yongbo

    2016-01-01

    It is well established that brain blood barrier dysfunction following the onset of seizures may lead to serum albumin extravasation into the brain. However, the effect of albumin extravasation on the development of epilepsy is yet to be fully elucidated. Previous studies have predominantly focused on the effect of albumin absorption by astrocytes; however, the present study investigated the effects of neuronal uptake of albumin in vitro and in kainic acid-induced Sprague-Dawley rat models of temporal lobe epilepsy. In the present study, electroencephalogram recordings were conducted to record seizure onset, Nissl and Evans blue staining were used to detect neuronal damage and albumin extravasation, respectively, and double immunofluorescence was used to explore neuronal absorption of albumin. Cell counting was also conducted in vitro to determine whether albumin contributes to neuronal death. The results of the present study indicated that extravasated serum albumin was absorbed by neurons, and the neurons that had absorbed albumin died and were dissolved 28 days after seizure onset in vivo. Furthermore, significant neuronal death was detected after albumin absorption in vitro in a dose- and time-dependent manner. These results suggested that albumin may be absorbed by neurons following the onset of seizures. Furthermore, the results indicated that neuronal albumin uptake may be associated with neuronal damage and death in epileptic seizures. Therefore, attenuating albumin extravasation following epileptic seizures may reduce brain damage and slow the development of epilepsy. PMID:27446263

  10. Glimepiride protects neurons against amyloid-β-induced synapse damage.

    PubMed

    Osborne, Craig; West, Ewan; Nolan, William; McHale-Owen, Harriet; Williams, Alun; Bate, Clive

    2016-02-01

    Alzheimer's disease is associated with the accumulation within the brain of amyloid-β (Aβ) peptides that damage synapses and affect memory acquisition. This process can be modelled by observing the effects of Aβ on synapses in cultured neurons. The addition of picomolar concentrations of soluble Aβ derived from brain extracts triggered the loss of synaptic proteins including synaptophysin, synapsin-1 and cysteine string protein from cultured neurons. Glimepiride, a sulphonylurea used for the treatment of diabetes, protected neurons against synapse damage induced by Aβ. The protective effects of glimepiride were multi-faceted. Glimepiride treatment was associated with altered synaptic membranes including the loss of specific glycosylphosphatidylinositol (GPI)-anchored proteins including the cellular prion protein (PrP(C)) that acts as a receptor for Aβ42, increased synaptic gangliosides and altered cell signalling. More specifically, glimepiride reduced the Aβ-induced increase in cholesterol and the Aβ-induced activation of cytoplasmic phospholipase A2 (cPLA2) in synapses that occurred within cholesterol-dense membrane rafts. Aβ42 binding to glimepiride-treated neurons was not targeted to membrane rafts and less Aβ42 accumulated within synapses. These studies indicate that glimepiride modified the membrane micro-environments in which Aβ-induced signalling leads to synapse damage. In addition, soluble PrP(C), released from neurons by glimepiride, neutralised Aβ-induced synapse damage. Such observations raise the possibility that glimepiride may reduce synapse damage and hence delay the progression of cognitive decline in Alzheimer's disease. PMID:26432105

  11. Phagocytosis of neuronal debris by microglia is associated with neuronal damage in multiple sclerosis.

    PubMed

    Huizinga, Ruth; van der Star, Baukje J; Kipp, Markus; Jong, Rosa; Gerritsen, Wouter; Clarner, Tim; Puentes, Fabiola; Dijkstra, Christine D; van der Valk, Paul; Amor, Sandra

    2012-03-01

    Neuroaxonal degeneration is a pathological hallmark of multiple sclerosis (MS) contributing to irreversible neurological disability. Pathological mechanisms leading to axonal damage include autoimmunity to neuronal antigens. In actively demyelinating lesions, myelin is phagocytosed by microglia and blood-borne macrophages, whereas the fate of degenerating or damaged axons is unclear. Phagocytosis is essential for clearing neuronal debris to allow repair and regeneration. However, phagocytosis may lead to antigen presentation and autoimmunity, as has been described for neuroaxonal antigens. Despite this notion, it is unknown whether phagocytosis of neuronal antigens occurs in MS. Here, we show using novel, well-characterized antibodies to axonal antigens, that axonal damage is associated with HLA-DR expressing microglia/macrophages engulfing axonal bulbs, indicative of axonal damage. Neuronal proteins were frequently observed inside HLA-DR(+) cells in areas of axonal damage. In vitro, phagocytosis of neurofilament light (NF-L), present in white and gray matter, was observed in human microglia. The number of NF-L or myelin basic protein (MBP) positive cells was quantified using the mouse macrophage cell line J774.2. Intracellular colocalization of NF-L with the lysosomal membrane protein LAMP1 was observed using confocal microscopy confirming that NF-L is taken up and degraded by the cell. In vivo, NF-L and MBP was observed in cerebrospinal fluid cells from patients with MS, suggesting neuronal debris is drained by this route after axonal damage. In summary, neuroaxonal debris is engulfed, phagocytosed, and degraded by HLA-DR(+) cells. Although uptake is essential for clearing neuronal debris, phagocytic cells could also play a role in augmenting autoimmunity to neuronal antigens. PMID:22161990

  12. Narratives and Neurons: Stories of Damaged Brains

    PubMed Central

    Mickley, G. Andrew; Hoyt, Daniel A.

    2010-01-01

    Stories register in human memory in special ways, and stories about neurological cases can entertain and move a reader while simultaneously being an important part of any neuroscience curriculum. Here we describe a course taught in the context of the liberal arts curriculum of Baldwin-Wallace College. Students from a variety of disciplines learned basic neuroanatomy, neurophysiology and neurochemistry and then used this information to help them understand published neurological case studies, which were analyzed for their literary as well as scientific qualities. Later in the course, students were paired with a person with a neurological disorder and they investigated their cases in some depth. The capstone experience was a monograph that aimed to be both good science and good story telling. Narratives and Neurons was team taught by faculty from the Neuroscience and English departments. However, the case studies were shaped and improved by all the class participants using writing workshop methods common to creative writing classes. Assessments of this course were very favorable, suggesting that students find that the work enhanced their resourcefulness and challenged their abilities to critically evaluate and problem solve. Some of the cases have found their way into the peer-reviewed literature. Moreover, the interaction between students and individuals with neurological disorders provided a diversity of experiences that enriched the lives of all the participants. PMID:23493566

  13. Progression of Neuronal Damage in an In Vitro Model of the Ischemic Penumbra

    PubMed Central

    le Feber, Joost; Tzafi Pavlidou, Stelina; Erkamp, Niels; van Putten, Michel J. A. M.; Hofmeijer, Jeannette

    2016-01-01

    Improvement of neuronal recovery in the ischemic penumbra around a brain infarct has a large potential to advance clinical recovery of patients with acute ischemic stroke. However, pathophysiological mechanisms leading to either recovery or secondary damage in the penumbra are not completely understood. We studied neuronal dynamics in a model system of the penumbra consisting of networks of cultured cortical neurons exposed to controlled levels and durations of hypoxia. Short periods of hypoxia (pO2≈20mmHg) reduced spontaneous activity, due to impeded synaptic function. After ≈6 hours, activity and connectivity partially recovered, even during continuing hypoxia. If the oxygen supply was restored within 12 hours, changes in network connectivity were completely reversible. For longer periods of hypoxia (12–30 h), activity levels initially increased, but eventually decreased and connectivity changes became partially irreversible. After ≈30 hours, all functional connections disappeared and no activity remained. Since this complete silence seemed unrelated to hypoxic depths, but always followed an extended period of low activity, we speculate that irreversible damage (at least partly) results from insufficient neuronal activation. This opens avenues for therapies to improve recovery by neuronal activation. PMID:26871437

  14. Mitochondrial fission is an acute and adaptive response in injured motor neurons.

    PubMed

    Kiryu-Seo, Sumiko; Tamada, Hiromi; Kato, Yukina; Yasuda, Katsura; Ishihara, Naotada; Nomura, Masatoshi; Mihara, Katsuyoshi; Kiyama, Hiroshi

    2016-01-01

    Successful recovery from neuronal damage requires a huge energy supply, which is provided by mitochondria. However, the physiological relevance of mitochondrial dynamics in damaged neurons in vivo is poorly understood. To address this issue, we established unique bacterial artificial chromosome transgenic (BAC Tg) mice, which develop and function normally, but in which neuronal injury induces labelling of mitochondria with green fluorescent protein (GFP) and expression of cre recombinase. GFP-labelled mitochondria in BAC Tg mice appear shorter in regenerating motor axons soon after nerve injury compared with mitochondria in non-injured axons, suggesting the importance of increased mitochondrial fission during the early phase of nerve regeneration. Crossing the BAC Tg mice with mice carrying a floxed dynamin-related protein 1 gene (Drp1), which is necessary for mitochondrial fission, ablates mitochondrial fission specifically in injured neurons. Injury-induced Drp1-deficient motor neurons show elongated or abnormally gigantic mitochondria, which have impaired membrane potential and axonal transport velocity during the early phase after injury, and eventually promote neuronal death. Our in vivo data suggest that acute and prominent mitochondrial fission during the early stage after nerve injury is an adaptive response and is involved in the maintenance of mitochondrial and neuronal integrity to prevent neurodegeneration. PMID:27319806

  15. Mitochondrial fission is an acute and adaptive response in injured motor neurons

    PubMed Central

    Kiryu-Seo, Sumiko; Tamada, Hiromi; Kato, Yukina; Yasuda, Katsura; Ishihara, Naotada; Nomura, Masatoshi; Mihara, Katsuyoshi; Kiyama, Hiroshi

    2016-01-01

    Successful recovery from neuronal damage requires a huge energy supply, which is provided by mitochondria. However, the physiological relevance of mitochondrial dynamics in damaged neurons in vivo is poorly understood. To address this issue, we established unique bacterial artificial chromosome transgenic (BAC Tg) mice, which develop and function normally, but in which neuronal injury induces labelling of mitochondria with green fluorescent protein (GFP) and expression of cre recombinase. GFP-labelled mitochondria in BAC Tg mice appear shorter in regenerating motor axons soon after nerve injury compared with mitochondria in non-injured axons, suggesting the importance of increased mitochondrial fission during the early phase of nerve regeneration. Crossing the BAC Tg mice with mice carrying a floxed dynamin-related protein 1 gene (Drp1), which is necessary for mitochondrial fission, ablates mitochondrial fission specifically in injured neurons. Injury-induced Drp1-deficient motor neurons show elongated or abnormally gigantic mitochondria, which have impaired membrane potential and axonal transport velocity during the early phase after injury, and eventually promote neuronal death. Our in vivo data suggest that acute and prominent mitochondrial fission during the early stage after nerve injury is an adaptive response and is involved in the maintenance of mitochondrial and neuronal integrity to prevent neurodegeneration. PMID:27319806

  16. A perfusion chamber for physiological studies with acutely dissociated neurons.

    PubMed

    Wonderlin, W F; Weinreich, D

    1987-11-01

    We describe a recording chamber that immobilizes acutely dissociated neurons on an ultra-fine mesh grid positioned above a moving stream of perfusate. This chamber is easily fabricated and has two attributes for single-electrode voltage-clamp or patch-clamp recording: (1) shallow immersion (less than 20 micron) of the neurons, and (2) stable recording with rapid perfusion rates. PMID:3695568

  17. Damage of hippocampal neurons in rats with chronic alcoholism

    PubMed Central

    Du, Ailin; Jiang, Hongbo; Xu, Lei; An, Na; Liu, Hui; Li, Yinsheng; Zhang, Ruiling

    2014-01-01

    Chronic alcoholism can damage the cytoskeleton and aggravate neurological deficits. However, the effect of chronic alcoholism on hippocampal neurons remains unclear. In this study, a model of chronic alcoholism was established in rats that were fed with 6% alcohol for 42 days. Endogenous hydrogen sulfide content and cystathionine-beta-synthase activity in the hippocampus of rats with chronic alcoholism were significantly increased, while F-actin expression was decreased. Hippocampal neurons in rats with chronic alcoholism appeared to have a fuzzy nuclear membrane, mitochondrial edema, and ruptured mitochondrial crista. These findings suggest that chronic alcoholism can cause learning and memory decline in rats, which may be associated with the hydrogen sulfide/cystathionine-beta-synthase system, mitochondrial damage and reduced expression of F-actin. PMID:25368648

  18. Tf-lipoplex-mediated c-Jun silencing improves neuronal survival following excitotoxic damage in vivo.

    PubMed

    Cardoso, A L C; Costa, P; de Almeida, L P; Simões, S; Plesnila, N; Culmsee, C; Wagner, E; de Lima, M C Pedroso

    2010-03-19

    Excitotoxicity is one of the main features responsible for neuronal cell death after acute brain injury and in several neurodegenerative disorders, for which only few therapeutic options are currently available. In this work, RNA interference was employed to identify and validate a potential target for successful treatment of excitotoxic brain injury, the transcription factor c-Jun. The nuclear translocation of c-Jun and its upregulation are early events following glutamate-induced excitotoxic damage in primary neuronal cultures. We present evidence for the efficient knockdown of this transcription factor using a non-viral vector consisting of cationic liposomes associated to transferrin (Tf-lipoplexes). Tf-lipoplexes were able to deliver anti-c-Jun siRNAs to neuronal cells in culture, resulting in efficient silencing of c-Jun mRNA and protein and in a significant decrease of cell death following glutamate-induced damage or oxygen-glucose deprivation. This formulation also leads to a significant c-Jun knockdown in the mouse hippocampus in vivo, resulting in the attenuation of both neuronal death and inflammation following kainic acid-mediated lesion of this region. Furthermore, a strong reduction of seizure activity and cytokine production was observed in animals treated with anti-c-Jun siRNAs. These findings demonstrate the efficient delivery of therapeutic siRNAs to the brain by Tf-lipoplexes and validate c-Jun as a promising therapeutic target in neurodegenerative disorders involving excitotoxic lesions. PMID:19913061

  19. Myelin Basic Protein Induces Neuron-Specific Toxicity by Directly Damaging the Neuronal Plasma Membrane

    PubMed Central

    Zheng, Sixin; Liu, Xiao; Jin, Jinghua; Ren, Yi; Luo, Jianhong

    2014-01-01

    The central nervous system (CNS) insults may cause massive demyelination and lead to the release of myelin-associated proteins including its major component myelin basic protein (MBP). MBP is reported to induce glial activation but its effect on neurons is still little known. Here we found that MBP specifically bound to the extracellular surface of the neuronal plasma membrane and induced neurotoxicity in vitro. This effect of MBP on neurons was basicity-dependent because the binding was blocked by acidic lipids and competed by other basic proteins. Further studies revealed that MBP induced damage to neuronal membrane integrity and function by depolarizing the resting membrane potential, increasing the permeability to cations and other molecules, and decreasing the membrane fluidity. At last, artificial liposome vesicle assay showed that MBP directly disturbed acidic lipid bilayer and resulted in increased membrane permeability. These results revealed that MBP induces neurotoxicity through its direct interaction with acidic components on the extracellular surface of neuronal membrane, which may suggest a possible contribution of MBP to the pathogenesis in the CNS disorders with myelin damage. PMID:25255088

  20. Effects of acute spinalization on neurons of postural networks

    PubMed Central

    Zelenin, Pavel V.; Lyalka, Vladimir F.; Hsu, Li-Ju; Orlovsky, Grigori N.; Deliagina, Tatiana G.

    2016-01-01

    Postural limb reflexes (PLRs) represent a substantial component of postural corrections. Spinalization results in loss of postural functions, including disappearance of PLRs. The aim of the present study was to characterize the effects of acute spinalization on two populations of spinal neurons (F and E) mediating PLRs, which we characterized previously. For this purpose, in decerebrate rabbits spinalized at T12, responses of interneurons from L5 to stimulation causing PLRs before spinalization, were recorded. The results were compared to control data obtained in our previous study. We found that spinalization affected the distribution of F- and E-neurons across the spinal grey matter, caused a significant decrease in their activity, as well as disturbances in processing of posture-related sensory inputs. A two-fold decrease in the proportion of F-neurons in the intermediate grey matter was observed. Location of populations of F- and E-neurons exhibiting significant decrease in their activity was determined. A dramatic decrease of the efficacy of sensory input from the ipsilateral limb to F-neurons, and from the contralateral limb to E-neurons was found. These changes in operation of postural networks underlie the loss of postural control after spinalization, and represent a starting point for the development of spasticity. PMID:27302149

  1. Effects of acute spinalization on neurons of postural networks.

    PubMed

    Zelenin, Pavel V; Lyalka, Vladimir F; Hsu, Li-Ju; Orlovsky, Grigori N; Deliagina, Tatiana G

    2016-01-01

    Postural limb reflexes (PLRs) represent a substantial component of postural corrections. Spinalization results in loss of postural functions, including disappearance of PLRs. The aim of the present study was to characterize the effects of acute spinalization on two populations of spinal neurons (F and E) mediating PLRs, which we characterized previously. For this purpose, in decerebrate rabbits spinalized at T12, responses of interneurons from L5 to stimulation causing PLRs before spinalization, were recorded. The results were compared to control data obtained in our previous study. We found that spinalization affected the distribution of F- and E-neurons across the spinal grey matter, caused a significant decrease in their activity, as well as disturbances in processing of posture-related sensory inputs. A two-fold decrease in the proportion of F-neurons in the intermediate grey matter was observed. Location of populations of F- and E-neurons exhibiting significant decrease in their activity was determined. A dramatic decrease of the efficacy of sensory input from the ipsilateral limb to F-neurons, and from the contralateral limb to E-neurons was found. These changes in operation of postural networks underlie the loss of postural control after spinalization, and represent a starting point for the development of spasticity. PMID:27302149

  2. Neuronal mechanism for acute mechanosensitivity in tactile-foraging waterfowl

    PubMed Central

    Schneider, Eve R.; Mastrotto, Marco; Laursen, Willem J.; Schulz, Vincent P.; Goodman, Jena B.; Funk, Owen H.; Gallagher, Patrick G.; Gracheva, Elena O.; Bagriantsev, Sviatoslav N.

    2014-01-01

    Relying almost exclusively on their acute sense of touch, tactile-foraging birds can feed in murky water, but the cellular mechanism is unknown. Mechanical stimuli activate specialized cutaneous end organs in the bill, innervated by trigeminal afferents. We report that trigeminal ganglia (TG) of domestic and wild tactile-foraging ducks exhibit numerical expansion of large-diameter mechanoreceptive neurons expressing the mechano-gated ion channel Piezo2. These features are not found in visually foraging birds. Moreover, in the duck, the expansion of mechanoreceptors occurs at the expense of thermosensors. Direct mechanical stimulation of duck TG neurons evokes high-amplitude depolarizing current with a low threshold of activation, high signal amplification gain, and slow kinetics of inactivation. Together, these factors contribute to efficient conversion of light mechanical stimuli into neuronal excitation. Our results reveal an evolutionary strategy to hone tactile perception in vertebrates at the level of primary afferents. PMID:25246547

  3. Neuron specific enolase: a promising therapeutic target in acute spinal cord injury.

    PubMed

    Haque, Azizul; Ray, Swapan K; Cox, April; Banik, Naren L

    2016-06-01

    Enolase is a multifunctional protein, which is expressed abundantly in the cytosol. Upon stimulatory signals, enolase can traffic to cell surface and contribute to different pathologies including injury, autoimmunity, infection, inflammation, and cancer. Cell-surface expression of enolase is often detected on activated macrophages, microglia/macrophages, microglia, and astrocytes, promoting extracellular matrix degradation, production of pro-inflammatory cytokines/chemokines, and invasion of inflammatory cells in the sites of injury and inflammation. Inflammatory stimulation also induces translocation of enolase from the cytosolic pool to the cell surface where it can act as a plasminogen receptor and promote extracellular matrix degradation and tissue damage. Spinal cord injury (SCI) is a devastating debilitating condition characterized by progressive pathological changes including complex and evolving molecular cascades, and insights into the role of enolase in multiple inflammatory events have not yet been fully elucidated. Neuronal damage following SCI is associated with an elevation of neuron specific enolase (NSE), which is also known to play a role in the pathogenesis of hypoxic-ischemic brain injury. Thus, NSE is now considered as a biomarker in ischemic brain damage, and it has recently been suggested to be a biomarker in traumatic brain injury (TBI), stroke and anoxic encephalopathy after cardiac arrest and acute SCI as well. This review article gives an overview of the current basic research and clinical studies on the role of multifunctional enolase in neurotrauma, with a special emphasis on NSE in acute SCI. PMID:26847611

  4. Damage to histaminergic tuberomammillary neurons and other hypothalamic neurons with traumatic brain injury.

    PubMed

    Valko, Philipp O; Gavrilov, Yury V; Yamamoto, Mihoko; Finn, Kristen; Reddy, Hasini; Haybaeck, Johannes; Weis, Serge; Scammell, Thomas E; Baumann, Christian R

    2015-01-01

    The need for increased sleep after traumatic brain injury is a common and disabling complaint, yet its etiology is unknown. Previous studies have demonstrated diffuse damage to various hypothalamic systems, but the integrity of the histaminergic tuberomammillary nucleus, a major arousal-promoting system located in the posterior hypothalamus, has never been examined in head trauma patients. Here, we demonstrate that severe head trauma is associated with a marked loss (41%) of histaminergic neurons. Reduced histamine signaling may contribute to increased sleep need, and therapies that enhance histaminergic tone may improve arousal after head trauma or other conditions. PMID:25363332

  5. Genetic damage in multiple organs of acutely exercised rats.

    PubMed

    Pozzi, Renan; Rosa, Jose C; Eguchi, Ricardo; Oller do Nascimento, Claudia M; Oyama, Lila M; Aguiar, Odair; Chaves, Marcelo D; Ribeiro, Daniel A

    2010-12-01

    The aim of this study was to investigate the effects of acute exercise on genomic damage in an animal model. Male adult Wistar rats were divided into the following groups: control and acute exercised (experimental). For this purpose, 15 animals were accustomed to running on a rodent treadmill for 15 min per day for 5 days (10-20 m min(-1); 08 grade). After 4 days at rest, active animals ran on the treadmill (22 m min(-1), 58 grade) till exhaustion. Cells from peripheral blood, liver, heart, and brain were collected after 0, 2, and 6 h after exercise. The results showed that acute exercise was able to induce genetic damage in peripheral blood cells after 2 and 6 h of exercise, whereas liver pointed out genetic damage for all periods evaluated. No genetic damage was induced either in brain or in heart cells. In conclusion, our results suggest that acute exercise could contribute to the genetic damage in peripheral blood and liver cells. It seems that liver is a sensitive organ to the genotoxic insult after acute exercise. PMID:20979236

  6. Erythropoietin administration protects retinal neurons from acute ischemia-reperfusion injury

    PubMed Central

    Junk, Anna K.; Mammis, Antonios; Savitz, Sean I.; Singh, Manjeet; Roth, Steven; Malhotra, Samit; Rosenbaum, Pearl S.; Cerami, Anthony; Brines, Michael; Rosenbaum, Daniel M.

    2002-01-01

    Erythropoietin (EPO) plays an important role in the brain's response to neuronal injury. Systemic administration of recombinant human EPO (rhEPO) protects neurons from injury after middle cerebral artery occlusion, traumatic brain injury, neuroinflammation, and excitotoxicity. Protection is in part mediated by antiapoptotic mechanisms. We conducted parallel studies of rhEPO in a model of transient global retinal ischemia induced by raising intraocular pressure, which is a clinically relevant model for retinal diseases. We observed abundant expression of EPO receptor (EPO-R) throughout the ischemic retina. Neutralization of endogenous EPO with soluble EPO-R exacerbated ischemic injury, which supports a crucial role for an endogenous EPO/EPO-R system in the survival and recovery of neurons after an ischemic insult. Systemic administration of rhEPO before or immediately after retinal ischemia not only reduced histopathological damage but also promoted functional recovery as assessed by electroretinography. Exogenous EPO also significantly diminished terminal deoxynucleotidyltransferase-mediated dUTP end labeling labeling of neurons in the ischemic retina, implying an antiapoptotic mechanism of action. These results further establish EPO as a neuroprotective agent in acute neuronal ischemic injury. PMID:12130665

  7. Time course of neuronal damage in the hippocampus following lithium-pilocarpine status epilepticus in 12-day-old rats.

    PubMed

    Druga, Rastislav; Mares, Pavel; Kubová, Hana

    2010-10-01

    Status epilepticus (SE) leads to serious damage in hippocampus of the adult brain. Much less is known about immature brain where neuronal degeneration may have different localization and time course. Lithium-pilocarpine SE was induced in 12-day-old male Wistar rats. Six different intervals after SE (from 4 h to 1 week) were studied using Fluoro-Jade B staining. Three to four animals were used for every interval. Severity of damage in individual parts of hippocampal formation was semi-quantified. A consistent neuronal damage occurred in all hippocampal fields (CA 1, CA 3, dentate gyrus) at all survival intervals. Hippocampal fields CA 1 and CA 3 exhibited degeneration of interneurons located mainly in stratum oriens and pyramidale at shorter intervals (4-12h). Massive degeneration of pyramidal cells started at 24h in CA 1 and at 48 h in CA 3. Dentate gyrus exhibited degenerating neurons in granular layer with a peak at short intervals (4-8 h), and molecular layer was spared. The lower blade of dentate gyrus was more affected than the upper blade. Damage of hilar neurons was negligible. Our results demonstrate that SE elicited in immature rats causes acute neurodegeneration in the hippocampus. Time course of this degeneration is different for individual parts of hippocampal formation and for individual cell types. PMID:20673826

  8. Neuronal oxidative injury and dendritic damage induced by carbofuran: Protection by memantine

    SciTech Connect

    Gupta, Ramesh C. . E-mail: ramesh.gupta@murraystate.edu; Milatovic, Snjezana; Dettbarn, Wolf-D.; Aschner, Michael; Milatovic, Dejan

    2007-03-15

    Carbamate insecticides mediate their neurotoxicity by acetylcholinesterase (AChE) inactivation. Male Sprague-Dawley rats acutely intoxicated with the carbamate insecticide carbofuran (1.5 mg/kg, sc) developed hypercholinergic signs within 5-7 min of exposure, with maximal severity characterized by seizures within 30-60 min, lasting for about 2 h. At the time of peak severity, compared with controls, AChE was maximally inhibited (by 82-90%), radical oxygen species (ROS) markers (F{sub 2}-isoprostanes, F{sub 2}-IsoPs; and F{sub 4}-neuroprostanes, F{sub 4}-NeuroPs) were elevated 2- to 3-fold, and the radical nitrogen species (RNS) marker citrulline was elevated 4- to 8-fold in discrete brain regions (cortex, amygdala, and hippocampus). In addition, levels of high-energy phosphates (HEPs) were significantly reduced (ATP, by 43-56%; and phosphocreatine, by 37-48%). Values of total adenine nucleotides and total creatine compounds declined markedly (by 41-56% and 35-45%, respectively), while energy charge potential remained unchanged. Quantitative morphometric analysis of pyramidal neurons of the hippocampal CA1 region revealed significant decreases in dendritic lengths (by 64%) and spine density (by 60%). Pretreatment with the N-methyl-D-aspartate (NMDA) receptor antagonist memantine (18 mg/kg, sc), in combination with atropine sulfate (16 mg/kg, sc), significantly attenuated carbofuran-induced changes in AChE activity and levels of F{sub 2}-IsoPs and F{sub 4}-NeuroPs, declines in HEPs, as well as the alterations in morphology of hippocampal neurons. MEM and ATS pretreatment also protected rats from carbofuran-induced hypercholinergic behavioral activity, including seizures. These findings support the involvement of ROS and RNS in seizure-induced neuronal injury and suggest that memantine by preventing carbofuran-induced neuronal hyperactivity blocks pathways associated with oxidative damage in neurons.

  9. ACUTE ETHANOL SUPPRESSES GLUTAMATERGIC NEUROTRANSMISSION THROUGH ENDOCANNABINOIDS IN HIPPOCAMPAL NEURONS

    PubMed Central

    Basavarajappa, Balapal S.; Ninan, Ipe; Arancio, Ottavio

    2008-01-01

    Ethanol exposure during fetal development is a leading cause of long-term cognitive impairments. Studies suggest that ethanol exposure have deleterious effects on the hippocampus, a brain region that is important for learning and memory. Ethanol exerts its effects, in part, via alterations in glutamatergic neurotransmission, which is critical for the maturation of neuronal circuits during development. The current literature strongly supports the growing evidence that ethanol inhibits glutamate release in the neonatal CA1 hippocampal region. However, the exact molecular mechanism responsible for this effect is not well understood. In this study, we show that ethanol enhances endocannabinoid (EC) levels in cultured hippocampal neurons, possibly through calcium pathways. Acute ethanol depresses miniature postsynaptic current (mEPSC) frequencies without affecting their amplitude. This suggests that ethanol inhibits glutamate release. The CB1 receptors (CB1Rs) present on presynaptic neurons are not altered by acute ethanol. The CB1R antagonist SR 141716A reverses ethanol-induced depression of mEPSC frequency. Drugs that are known to enhance the in vivo function of ECs occlude ethanol effects on mEPSC frequency. Chelation of postsynaptic calcium by EGTA antagonizes ethanol-induced depression of mEPSC frequency. The activation of CB1R with the selective agonist WIN55,212-2 also suppresses the mEPSC frequency. This WIN55,212-2 effect is similar to the ethanol effects and is reversed by SR141716A. In addition, tetani-induced excitatory postsynaptic currents (EPSCs) are depressed by acute ethanol. SR141716A significantly reverses ethanol effects on evoked EPSC amplitude in a dual recording preparation. These observations, taken together, suggest the participation of ECs as retrograde messengers in the ethanol-induced depression of synaptic activities. PMID:18796007

  10. Neuroprotection by gonadal steroid hormones in acute brain damage requires cooperation with astroglia and microglia.

    PubMed

    Johann, Sonja; Beyer, Cordian

    2013-09-01

    The neuroactive steroids 17β-estradiol and progesterone control a broad spectrum of neural functions. Besides their roles in the regulation of classical neuroendocrine loops, they strongly influence motor and cognitive systems, behavior, and modulate brain performance at almost every level. Such a statement is underpinned by the widespread and lifelong expression pattern of all types of classical and non-classical estrogen and progesterone receptors in the CNS. The life-sustaining power of neurosteroids for tattered or seriously damaged neurons aroused interest in the scientific community in the past years to study their ability for therapeutic use under neuropathological challenges. Documented by excellent studies either performed in vitro or in adequate animal models mimicking acute toxic or chronic neurodegenerative brain disorders, both hormones revealed a high potency to protect neurons from damage and saved neural systems from collapse. Unfortunately, neurons, astroglia, microglia, and oligodendrocytes are comparably target cells for both steroid hormones. This hampers the precise assignment and understanding of neuroprotective cellular mechanisms activated by both steroids. In this article, we strive for a better comprehension of the mutual reaction between these steroid hormones and the two major glial cell types involved in the maintenance of brain homeostasis, astroglia and microglia, during acute traumatic brain injuries such as stroke and hypoxia. In particular, we attempt to summarize steroid-activated cellular signaling pathways and molecular responses in these cells and their contribution to dampening neuroinflammation and neural destruction. This article is part of a Special Issue entitled 'CSR 2013'. PMID:23196064

  11. Differential transcriptional profiling of damaged and intact adjacent dorsal root ganglia neurons in neuropathic pain.

    PubMed

    Reinhold, A K; Batti, L; Bilbao, D; Buness, A; Rittner, H L; Heppenstall, P A

    2015-01-01

    Neuropathic pain, caused by a lesion in the somatosensory system, is a severely impairing mostly chronic disease. While its underlying molecular mechanisms are not thoroughly understood, neuroimmune interactions as well as changes in the pain pathway such as sensitization of nociceptors have been implicated. It has been shown that not only are different cell types involved in generation and maintenance of neuropathic pain, like neurons, immune and glial cells, but, also, intact adjacent neurons are relevant to the process. Here, we describe an experimental approach to discriminate damaged from intact adjacent neurons in the same dorsal root ganglion (DRG) using differential fluorescent neuronal labelling and fluorescence-activated cell sorting (FACS). Two fluorescent tracers, Fluoroemerald (FE) and 1-dioctadecyl-3,3,3,3-tetramethylindocarbocyanine perchlorate (DiI), were used, whose properties allow us to distinguish between damaged and intact neurons. Subsequent sorting permitted transcriptional analysis of both groups. Results and qPCR validation show a strong regulation in damaged neurons versus contralateral controls as well as a moderate regulation in adjacent neurons. Data for damaged neurons reveal an mRNA expression pattern consistent with established upregulated genes like galanin, which supports our approach. Moreover, novel genes were found strongly regulated such as corticotropin-releasing hormone (CRH), providing novel targets for further research. Differential fluorescent neuronal labelling and sorting allows for a clear distinction between primarily damaged neuropathic neurons and "bystanders," thereby facilitating a more detailed understanding of their respective roles in neuropathic processes in the DRG. PMID:25880204

  12. Differential Transcriptional Profiling of Damaged and Intact Adjacent Dorsal Root Ganglia Neurons in Neuropathic Pain

    PubMed Central

    Reinhold, A. K.; Batti, L.; Bilbao, D.; Buness, A.; Rittner, H. L.; Heppenstall, P. A.

    2015-01-01

    Neuropathic pain, caused by a lesion in the somatosensory system, is a severely impairing mostly chronic disease. While its underlying molecular mechanisms are not thoroughly understood, neuroimmune interactions as well as changes in the pain pathway such as sensitization of nociceptors have been implicated. It has been shown that not only are different cell types involved in generation and maintenance of neuropathic pain, like neurons, immune and glial cells, but, also, intact adjacent neurons are relevant to the process. Here, we describe an experimental approach to discriminate damaged from intact adjacent neurons in the same dorsal root ganglion (DRG) using differential fluorescent neuronal labelling and fluorescence-activated cell sorting (FACS). Two fluorescent tracers, Fluoroemerald (FE) and 1-dioctadecyl-3,3,3,3-tetramethylindocarbocyanine perchlorate (DiI), were used, whose properties allow us to distinguish between damaged and intact neurons. Subsequent sorting permitted transcriptional analysis of both groups. Results and qPCR validation show a strong regulation in damaged neurons versus contralateral controls as well as a moderate regulation in adjacent neurons. Data for damaged neurons reveal an mRNA expression pattern consistent with established upregulated genes like galanin, which supports our approach. Moreover, novel genes were found strongly regulated such as corticotropin-releasing hormone (CRH), providing novel targets for further research. Differential fluorescent neuronal labelling and sorting allows for a clear distinction between primarily damaged neuropathic neurons and “bystanders,” thereby facilitating a more detailed understanding of their respective roles in neuropathic processes in the DRG. PMID:25880204

  13. Selective neuronal vulnerability of human hippocampal CA1 neurons: lesion evolution, temporal course, and pattern of hippocampal damage in diffusion-weighted MR imaging.

    PubMed

    Bartsch, Thorsten; Döhring, Juliane; Reuter, Sigrid; Finke, Carsten; Rohr, Axel; Brauer, Henriette; Deuschl, Günther; Jansen, Olav

    2015-11-01

    The CA1 (cornu ammonis) region of hippocampus is selectively vulnerable to a variety of metabolic and cytotoxic insults, which is mirrored in a delayed neuronal death of CA1 neurons. The basis and mechanisms of this regional susceptibility of CA1 neurons are poorly understood, and the correlates in human diseases affecting the hippocampus are not clear. Adopting a translational approach, the lesion evolution, temporal course, pattern of diffusion changes, and damage in hippocampal CA1 in acute neurologic disorders were studied using high-resolution magnetic resonance imaging. In patients with hippocampal ischemia (n=50), limbic encephalitis (n=30), after status epilepticus (n=17), and transient global amnesia (n=53), the CA1 region was selectively affected compared with other CA regions of the hippocampus. CA1 neurons exhibited a maximum decrease of apparent diffusion coefficient (ADC) 48 to 72 hours after the insult, irrespective of the nature of the insult. Hypoxic-ischemic insults led to a significant lower ADC suggesting that the ischemic insult results in a stronger impairment of cellular metabolism. The evolution of diffusion changes show that CA1 diffusion lesions mirror the delayed time course of the pathophysiologic cascade typically observed in animal models. Studying the imaging correlates of hippocampal damage in humans provides valuable insight into the pathophysiology and neurobiology of the hippocampus. PMID:26082014

  14. Molecular Regulation of DNA Damage-Induced Apoptosis in Neurons of Cerebral Cortex

    PubMed Central

    Liu, Zhiping; Pipino, Jacqueline; Chestnut, Barry; Landek, Melissa A.

    2009-01-01

    Cerebral cortical neuron degeneration occurs in brain disorders manifesting throughout life, but the mechanisms are understood poorly. We used cultured embryonic mouse cortical neurons and an in vivo mouse model to study mechanisms of DNA damaged-induced apoptosis in immature and differentiated neurons. p53 drives apoptosis of immature and differentiated cortical neurons through its rapid and prominent activation stimulated by DNA strand breaks induced by topoisomerase-I and -II inhibition. Blocking p53-DNA transactivation with α-pifithrin protects immature neurons; blocking p53-mitochondrial functions with μ-pifithrin protects differentiated neurons. Mitochondrial death proteins are upregulated in apoptotic immature and differentiated neurons and have nonredundant proapoptotic functions; Bak is more dominant than Bax in differentiated neurons. p53 phosphorylation is mediated by ataxia telangiectasia mutated (ATM) kinase. ATM inactivation is antiapoptotic, particularly in differentiated neurons, whereas inhibition of c-Abl protects immature neurons but not differentiated neurons. Cell death protein expression patterns in mouse forebrain are mostly similar to cultured neurons. DNA damage induces prominent p53 activation and apoptosis in cerebral cortex in vivo. Thus, DNA strand breaks in cortical neurons induce rapid p53-mediated apoptosis through actions of upstream ATM and c-Abl kinases and downstream mitochondrial death proteins. This molecular network operates through variations depending on neuron maturity. PMID:18820287

  15. Lymphocytes modulate innate immune responses and neuronal damage in experimental meningitis.

    PubMed

    Hoffmann, Olaf; Rung, Olga; Held, Josephin; Boettcher, Chotima; Prokop, Stefan; Stenzel, Werner; Priller, Josef

    2015-01-01

    In bacterial meningitis, excessive immune responses carry significant potential for damage to brain tissue even after successful antibiotic therapy. Bacterial meningitis is regarded primarily as the domain of innate immunity, and the role of lymphocytes remains unclear. We studied the contribution of lymphocytes to acute inflammation and neurodegeneration in experimental Toll-like receptor 2-driven meningitis, comparing wild-type mice with RAG-1-deficient mice that have no mature T and B lymphocytes. At 24 h after intrathecal challenge with the synthetic bacterial lipopeptide Pam(3)CysSK(4), RAG-1-deficient mice displayed more pronounced clinical impairment and an increased concentration of neutrophils, reduced expression of interleukin-10 (IL-10) mRNA, and increased expression of CXCL1 mRNA in the cerebrospinal fluid. Conversely, neuronal loss in the dentate gyrus was reduced in RAG-1-deficient mice, and expression of IL-10, transforming growth factor β and CCL2 mRNA by microglia was increased compared to wild-type mice. Adoptive transfer of wild-type lymphocytes reversed the enhanced meningeal inflammation and functional impairment observed in RAG-1-deficient mice. Our findings suggest compartment-specific effects of lymphocytes during acute bacterial meningitis, including attenuation of meningeal inflammation and shifting of microglial activation toward a more neurotoxic phenotype. PMID:25348636

  16. Spatiotemporal pattern of neuronal injury induced by DFP in rats: A model for delayed neuronal cell death following acute OP intoxication

    SciTech Connect

    Li Yonggang; Lein, Pamela J.; Liu Cuimei; Bruun, Donald A.; Tewolde, Teclemichael; Ford, Gregory; Ford, Byron D.

    2011-06-15

    Organophosphate (OP) neurotoxins cause acute cholinergic toxicity and seizures resulting in delayed brain damage and persistent neurological symptoms. Testing novel strategies for protecting against delayed effects of acute OP intoxication has been hampered by the lack of appropriate animal models. In this study, we characterize the spatiotemporal pattern of cellular injury after acute intoxication with the OP diisopropylfluorophosphate (DFP). Adult male Sprague-Dawley rats received pyridostigmine (0.1 mg/kg, im) and atropine methylnitrate (20 mg/kg, im) prior to DFP (9 mg/kg, ip) administration. All DFP-treated animals exhibited moderate to severe seizures within minutes after DFP injection but survived up to 72 h. AChE activity was significantly depressed in the cortex, hippocampus, subcortical brain tissue and cerebellum at 1 h post-DFP injection and this inhibition persisted for up to 72 h. Analysis of neuronal injury by Fluoro-Jade B (FJB) labeling revealed delayed neuronal cell death in the hippocampus, cortex, amygdala and thalamus, but not the cerebellum, starting at 4 h and persisting until 72 h after DFP treatment, although temporal profiles varied between brain regions. At 24 h post-DFP injection, the pattern of FJB labeling corresponded to TUNEL staining in most brain regions, and FJB-positive cells displayed reduced NeuN immunoreactivity but were not immunopositive for astrocytic (GFAP), oligodendroglial (O4) or macrophage/microglial (ED1) markers, demonstrating that DFP causes a region-specific delayed neuronal injury mediated in part by apoptosis. These findings indicate the feasibility of this model for testing neuroprotective strategies, and provide insight regarding therapeutic windows for effective pharmacological intervention following acute OP intoxication. - Research Highlights: > DFP induced neuronal FJB labeling starting at 4-8 h after treatment > The pattern of DFP-induced FJB labeling closely corresponded to TUNEL staining > FJB

  17. Ammonia-induced oxidative damage in neurons is prevented by resveratrol and lipoic acid with participation of heme oxygenase 1.

    PubMed

    Bobermin, Larissa Daniele; Wartchow, Krista Minéia; Flores, Marianne Pires; Leite, Marina Concli; Quincozes-Santos, André; Gonçalves, Carlos-Alberto

    2015-07-01

    Ammonia is a metabolite that, at high concentrations, is implicated in neurological disorders, such as hepatic encephalopathy (HE), which is associated with acute or chronic liver failure. Astrocytes are considered the primary target of ammonia toxicity in the central nervous system (CNS) because glutamine synthetase (GS), responsible for ammonia metabolism in CNS, is an astrocytic enzyme. Thus, neuronal dysfunction has been associated as secondary to astrocytic impairment. However, we demonstrated that ammonia can induce direct effects on neuronal cells. The cell viability was decreased by ammonia in SH-SY5Y cells and cerebellar granule neurons. In addition, ammonia induced increased reactive oxygen species (ROS) production and decreased GSH intracellular content, the main antioxidant in CNS. As ammonia neurotoxicity is strongly associated with oxidative stress, we also investigated the potential neuroprotective roles of the antioxidants, resveratrol (RSV) and lipoic acid (LA), against ammonia toxicity in cerebellar granule neurons. RSV and LA were able to prevent the oxidative damage induced by ammonia, maintaining the levels of ROS production and GSH close to basal values. Both antioxidants also decreased ROS production and increased GSH content under basal conditions (in the absence of ammonia). Moreover, we showed that heme oxygenase 1 (HO1), a protein associated with protection against stress conditions, is involved in the beneficial effects of RSV and LA in cerebellar granule neurons. Thus, this study reinforces the neuroprotective effects of RSV and LA. Although more studies in vivo are required, RSV and LA could represent interesting therapeutic strategies for the management of HE. PMID:26003724

  18. RAGE Expression and ROS Generation in Neurons: Differentiation versus Damage

    PubMed Central

    Piras, S.; Furfaro, A. L.; Domenicotti, C.; Traverso, N.; Marinari, U. M.; Pronzato, M. A.; Nitti, M.

    2016-01-01

    RAGE is a multiligand receptor able to bind advanced glycation end-products (AGEs), amphoterin, calgranulins, and amyloid-beta peptides, identified in many tissues and cells, including neurons. RAGE stimulation induces the generation of reactive oxygen species (ROS) mainly through the activity of NADPH oxidases. In neuronal cells, RAGE-induced ROS generation is able to favor cell survival and differentiation or to induce death through the imbalance of redox state. The dual nature of RAGE signaling in neurons depends not only on the intensity of RAGE activation but also on the ability of RAGE-bearing cells to adapt to ROS generation. In this review we highlight these aspects of RAGE signaling regulation in neuronal cells. PMID:27313835

  19. Sleep active cortical neurons expressing neuronal nitric oxide synthase are active after both acute sleep deprivation and chronic sleep restriction.

    PubMed

    Zielinski, M R; Kim, Y; Karpova, S A; Winston, S; McCarley, R W; Strecker, R E; Gerashchenko, D

    2013-09-01

    Non-rapid eye movement (NREM) sleep electroencephalographic (EEG) delta power (~0.5-4 Hz), also known as slow wave activity (SWA), is typically enhanced after acute sleep deprivation (SD) but not after chronic sleep restriction (CSR). Recently, sleep-active cortical neurons expressing neuronal nitric oxide synthase (nNOS) were identified and associated with enhanced SWA after short acute bouts of SD (i.e., 6h). However, the relationship between cortical nNOS neuronal activity and SWA during CSR is unknown. We compared the activity of cortical neurons expressing nNOS (via c-Fos and nNOS immuno-reactivity, respectively) and sleep in rats in three conditions: (1) after 18-h of acute SD; (2) after five consecutive days of sleep restriction (SR) (18-h SD per day with 6h ad libitum sleep opportunity per day); (3) and time-of-day matched ad libitum sleep controls. Cortical nNOS neuronal activity was enhanced during sleep after both 18-h SD and 5 days of SR treatments compared to control treatments. SWA and NREM sleep delta energy (the product of NREM sleep duration and SWA) were positively correlated with enhanced cortical nNOS neuronal activity after 18-h SD but not 5days of SR. That neurons expressing nNOS were active after longer amounts of acute SD (18h vs. 6h reported in the literature) and were correlated with SWA further suggest that these cells might regulate SWA. However, since these neurons were active after CSR when SWA was not enhanced, these findings suggest that mechanisms downstream of their activation are altered during CSR. PMID:23685166

  20. Classification of HIV-1-mediated neuronal dendritic and synaptic damage using multiple criteria linear programming.

    PubMed

    Zheng, Jialin; Zhuang, Wei; Yan, Nian; Kou, Gang; Peng, Hui; McNally, Clancy; Erichsen, David; Cheloha, Abby; Herek, Shelley; Shi, Chris

    2004-01-01

    The ability to identify neuronal damage in the dendritic arbor during HIV-1-associated dementia (HAD) is crucial for designing specific therapies for the treatment of HAD. To study this process, we utilized a computer-based image analysis method to quantitatively assess HIV-1 viral protein gp120 and glutamate-mediated individual neuronal damage in cultured cortical neurons. Changes in the number of neurites, arbors, branch nodes, cell body area, and average arbor lengths were determined and a database was formed (http://dm.ist.unomaha. edu/database.htm). We further proposed a two-class model of multiple criteria linear programming (MCLP) to classify such HIV-1-mediated neuronal dendritic and synaptic damages. Given certain classes, including treatments with brain-derived neurotrophic factor (BDNF), glutamate, gp120 or non-treatment controls from our in vitro experimental systems, we used the two-class MCLP model to determine the data patterns between classes in order to gain insight about neuronal dendritic damages. This knowledge can be applied in principle to the design and study of specific therapies for the prevention or reversal of neuronal damage associated with HAD. Finally, the MCLP method was compared with a well-known artificial neural network algorithm to test for the relative potential of different data mining applications in HAD research. PMID:15365193

  1. Remote limb preconditioning protects against ischemia-induced neuronal death through ameliorating neuronal oxidative DNA damage and parthanatos.

    PubMed

    Jin, Wei; Xu, Wei; Chen, Jing; Zhang, Xiaoxiao; Shi, Lei; Ren, Chuancheng

    2016-07-15

    Remote limb preconditioning (RPC) ameliorates ischemia-induced cerebral infarction and promotes neurological function recovery; however, the mechanism of RPC hasn't been fully understood, which limits its clinical application. The present study aimed at exploring the underlying mechanism of RPC through testing its effects on neuronal oxidative DNA damage and parthanatos in a rat focal cerebral ischemia model. Infarct volume was investigated by 2, 3, 5-triphenyltetrazolium chloride (TTC) staining, and neuronal survival was evaluated by Nissl staining. Oxidative DNA damage was investigated via analyzing the expression of 8-hydroxy-2'-deoxyguanosine (8-OHdG). Besides, terminal deoxynucleotidyl transferase-mediated biotinylated-dUTP nick-end labeling (TUNEL) and DNA laddering were utilized to evaluate neuronal DNA fragmentation. Moreover, we tested whether RPC regulated poly(ADP-ribose) polymer (PAR) and apoptosis inducing factor (AIF) pathway; thus, PAR expression, AIF translocation and AIF/histone H2AX (H2AX) interaction were investigated. The results showed that RPC exerted neuroprotective effects by ameliorating oxidative DNA damage and neuronal parthanatos; additionally, RPC suppressed PAR/AIF pathway through reducing AIF translocation and AIF/H2AX interaction. The present study further exposed neuroprotective mechanism of RPC, and provided new evidence for the research on RPC and ICS. PMID:27288768

  2. Neuronal PPARγ Deficiency Increases Susceptibility to Brain Damage after Cerebral Ischemia

    PubMed Central

    Zhao, Xiurong; Strong, Roger; Zhang, Jie; Sun, Guanghua; Tsien, Joe Z; Cui, Zhenzhong; Grotta, James C.; Aronowski, Jaroslaw

    2009-01-01

    Peroxisome proliferator-activated receptor gamma (PPARγ) plays a role in regulating a myriad of biological processes in virtually all brain cell types, including neurons. We and others have reported recently that drugs which activate PPARγ are effective in reducing damage to brain in distinct models of brain disease, including ischemia. However, the cell type responsible for PPARγ-mediated protection has not been established. In response to ischemia, PPARγ gene is robustly upregulated in neurons, suggesting that neuronal PPARγ may be a primary target for PPARγ-agonist mediated neuroprotection. To understand the contribution of neuronal PPARγ to ischemic injury, we generated conditional neuron-specific PPARγ knockout mice (N-PPARγ-KO). These mice are viable and appeared to be normal with respect to their gross behavior and brain anatomy. However, neuronal PPARγ deficiency caused these mice to experience significantly more brain damage and oxidative stress in response to middle cerebral artery occlusion. The primary cortical neurons harvested from N-PPARγ-KO mice, but not astroglia, exposed to ischemia in vitro demonstrated more damage and a reduced expression of numerous key gene products that could explain increased vulnerability, including: SOD1, catalase, glutathione S-transferase (GST), uncoupling protein-1 or transcription factor liver X receptor-alpha (LXRα). Also, PPARγ agonist based neuroprotective effect was lost in neurons from N-PPARγ neurons. Therefore, we conclude that PPARγ in neurons play an essential protective function, and that PPARγ agonists may have utility in neuronal self-defense, in addition to their well-established anti-inflammatory effect. PMID:19439596

  3. [Organ damage and cardiorenal syndrome in acute heart failure].

    PubMed

    Casado Cerrada, Jesús; Pérez Calvo, Juan Ignacio

    2014-03-01

    Heart failure is a complex syndrome that affects almost all organs and systems of the body. Signs and symptoms of organ dysfunction, in particular kidney dysfunction, may be accentuated or become evident for the first time during acute decompensation of heart failure. Cardiorenal syndrome has been defined as the simultaneous dysfunction of both the heart and the kidney, regardless of which of the two organs may have suffered the initial damage and regardless also of their previous functional status. Research into the mechanisms regulating the complex relationship between the two organs is prompting the search for new biomarkers to help physicians detect renal damage in subclinical stages. Hence, a preventive approach to renal dysfunction may be adopted in the clinical setting in the near future. This article provides a general overview of cardiorenal syndrome and an update of the physiopathological mechanisms involved. Special emphasis is placed on the role of visceral congestion as an emergent mechanism in this syndrome. PMID:24930080

  4. Unmyelinated type II afferent neurons report cochlear damage

    PubMed Central

    Liu, Chang; Glowatzki, Elisabeth; Fuchs, Paul Albert

    2015-01-01

    In the mammalian cochlea, acoustic information is carried to the brain by the predominant (95%) large-diameter, myelinated type I afferents, each of which is postsynaptic to a single inner hair cell. The remaining thin, unmyelinated type II afferents extend hundreds of microns along the cochlear duct to contact many outer hair cells. Despite this extensive arbor, type II afferents are weakly activated by outer hair cell transmitter release and are insensitive to sound. Intriguingly, type II afferents remain intact in damaged regions of the cochlea. Here, we show that type II afferents are activated when outer hair cells are damaged. This response depends on both ionotropic (P2X) and metabotropic (P2Y) purinergic receptors, binding ATP released from nearby supporting cells in response to hair cell damage. Selective activation of P2Y receptors increased type II afferent excitability by the closure of KCNQ-type potassium channels, a potential mechanism for the painful hypersensitivity (that we term “noxacusis” to distinguish from hyperacusis without pain) that can accompany hearing loss. Exposure to the KCNQ channel activator retigabine suppressed the type II fiber’s response to hair cell damage. Type II afferents may be the cochlea’s nociceptors, prompting avoidance of further damage to the irreparable inner ear. PMID:26553995

  5. Levetiracetam mitigates doxorubicin-induced DNA and synaptic damage in neurons.

    PubMed

    Manchon, Jose Felix Moruno; Dabaghian, Yuri; Uzor, Ndidi-Ese; Kesler, Shelli R; Wefel, Jeffrey S; Tsvetkov, Andrey S

    2016-01-01

    Neurotoxicity may occur in cancer patients and survivors during or after chemotherapy. Cognitive deficits associated with neurotoxicity can be subtle or disabling and frequently include disturbances in memory, attention, executive function and processing speed. Searching for pathways altered by anti-cancer treatments in cultured primary neurons, we discovered that doxorubicin, a commonly used anti-neoplastic drug, significantly decreased neuronal survival. The drug promoted the formation of DNA double-strand breaks in primary neurons and reduced synaptic and neurite density. Pretreatment of neurons with levetiracetam, an FDA-approved anti-epileptic drug, enhanced survival of chemotherapy drug-treated neurons, reduced doxorubicin-induced formation of DNA double-strand breaks, and mitigated synaptic and neurite loss. Thus, levetiracetam might be part of a valuable new approach for mitigating synaptic damage and, perhaps, for treating cognitive disturbances in cancer patients and survivors. PMID:27168474

  6. Levetiracetam mitigates doxorubicin-induced DNA and synaptic damage in neurons

    PubMed Central

    Manchon, Jose Felix Moruno; Dabaghian, Yuri; Uzor, Ndidi-Ese; Kesler, Shelli R.; Wefel, Jeffrey S.; Tsvetkov, Andrey S.

    2016-01-01

    Neurotoxicity may occur in cancer patients and survivors during or after chemotherapy. Cognitive deficits associated with neurotoxicity can be subtle or disabling and frequently include disturbances in memory, attention, executive function and processing speed. Searching for pathways altered by anti-cancer treatments in cultured primary neurons, we discovered that doxorubicin, a commonly used anti-neoplastic drug, significantly decreased neuronal survival. The drug promoted the formation of DNA double-strand breaks in primary neurons and reduced synaptic and neurite density. Pretreatment of neurons with levetiracetam, an FDA-approved anti-epileptic drug, enhanced survival of chemotherapy drug-treated neurons, reduced doxorubicin-induced formation of DNA double-strand breaks, and mitigated synaptic and neurite loss. Thus, levetiracetam might be part of a valuable new approach for mitigating synaptic damage and, perhaps, for treating cognitive disturbances in cancer patients and survivors. PMID:27168474

  7. Neuroprotective effect of a chuk-me-sun-dan on neurons from ischemic damage and neuronal cell toxicity.

    PubMed

    Chung, Tae-Wook; Koo, Byung-Soo; Choi, Eun-Gyu; Kim, Min-Gon; Lee, In-Seon; Kim, Cheorl-Ho

    2006-01-01

    Chukmesundan (CMSD), composed of the following 8 medicinal herbs including Panex ginseng C.A. MEYER, Atractylodes macrocephala KOID, Poria cocos WOLF, Pinellia ternata BREIT, Brassica alba BOISS, Aconitum carmichaeli DEBX, Cynanchum atratum BGE and Cuscuta chinensis LAM. CMSD is being used in Korea for the treatment of various symptoms accompanying hypertension and cerebrovascular disorders. This study was carried out to examine the effects of CMSD on cultured primary neuron cell, cell cytotoxicity and lipid peroxidation in Abeta-treated cells. Cell death was enhanced by addition of Abeta. Pretreatment of CMSD attenuated in cell killing induced by Abeta. The protective effect of the CMSD water extracts on Abeta-induced neuronal death was also observed by lactate dehydrogenase assay using cultured astrocyte cells. Abeta-induced cell death was protected by the water extract of CMSD in a dose-dependent manner, and 25-50 microg/ml was the most effective concentration. CMSD has been also shown to protect primary cultured neurons from N-methyl-D: -aspartate receptor-mediated glutamate toxicity. It was in vivo evidenced that CMSD protects neurons against ischemia-induced cell death. Moreover, oral administration of CMSD into mice prevented ischemia-induced learning disability and rescued hippocampal CA1 neurons from lethal ischemic damage. The neuroprotective action of exogenous CMSD was also confirmed by counting synapses in the hippocampal CA1 region. The presence of CMSD in neuron cultures rescued the neurons from nitrogen oxide (NO)-induced death. From these, it was suggested that CMSD may exert its neuroprotective effect by reducing the NO-mediated formation of free radicals or antagonizing their toxicity. PMID:16474991

  8. Endothelial Glycocalyx Damage Is Associated with Leptospirosis Acute Kidney Injury

    PubMed Central

    Libório, Alexandre Braga; Braz, Marcelo Boecker Munoz; Seguro, Antonio Carlos; Meneses, Gdayllon C.; Neves, Fernanda Macedo de Oliveira; Pedrosa, Danielle Carvalho; Cavalcanti, Luciano Pamplona de Góes; Martins, Alice Maria Costa; Daher, Elizabeth de Francesco

    2015-01-01

    Leptospirosis is a common disease in tropical countries, and the kidney is one of the main target organs. Membrane proteins of Leptospira are capable of causing endothelial damage in vitro, but there have been no studies in humans evaluating endothelial glycocalyx damage and its correlation with acute kidney injury (AKI). We performed a cohort study in an outbreak of leptospirosis among military personnel. AKI was diagnosed in 14 of 46 (30.4%) patients. Leptospirosis was associated with higher levels of intercellular adhesion molecule-1 (ICAM-1; 483.1 ± 31.7 versus 234.9 ± 24.4 mg/L, P < 0.001) and syndecan-1 (73.7 ± 15.9 versus 21.2 ± 7.9 ng/mL, P < 0.001) compared with exposed controls. Patients with leptospirosis-associated AKI had increased level of syndecan-1 (112.1 ± 45.4 versus 41.5 ± 11.7 ng/mL, P = 0.021) and ICAM-1 (576.9 ± 70.4 versus 434.9 ± 35.3, P = 0.034) compared with leptospirosis patients with no AKI. Association was verified between syndecan-1 and ICAM-1 with serum creatinine elevation and neutrophil gelatinase-associated lipocalin (NGAL) levels. This association remained even after multivariate analysis including other AKI-associated characteristics. Endothelial injury biomarkers are associated with leptospirosis-associated renal damage. PMID:25624405

  9. [Definition and biomarkers of acute renal damage: new perspectives].

    PubMed

    Seijas, M; Baccino, C; Nin, N; Lorente, J A

    2014-01-01

    The RIFLE and AKIN criteria have definitely help out to draw attention to the relationship between a deterioration of renal function that produces a small increase in serum creatinine and a worse outcome. However, the specific clinical utility of using these criteria remains to be well-defined. It is believed that the main use of these criteria is for the design of epidemiological studies and clinical trials to define inclusion criteria and objectives of an intervention. AKI adopting term, re-summoning former ARF terminology, it is appropriate to describe the clinical condition characterized by damage to kidney, in the same way as the term is used to describe acute lung damage where the lung injury situation still has not increased to a situation of organ failure (dysfunction). The serum and urine biomarkers (creatinine, urea, and diuresis) currently in use are not sensitive or specific for detecting kidney damage, limiting treatment options and potentially compromising the outcome. New biomarkers are being studied in order to diagnose an earlier and more specific AKI, with the potential to change the definition criteria of AKI with different stages, currently based in diuresis and serum creatinine. PMID:24880198

  10. Cholesterol synthesis inhibitors protect against platelet-activating factor-induced neuronal damage

    PubMed Central

    Bate, Clive; Rumbold, Louis; Williams, Alun

    2007-01-01

    Background Platelet-activating factor (PAF) is implicated in the neuronal damage that accompanies ischemia, prion disease and Alzheimer's disease (AD). Since some epidemiological studies demonstrate that statins, drugs that reduce cholesterol synthesis, have a beneficial effect on mild AD, we examined the effects of two cholesterol synthesis inhibitors on neuronal responses to PAF. Methods Primary cortical neurons were treated with cholesterol synthesis inhibitors (simvastatin or squalestatin) prior to incubation with different neurotoxins. The effects of these drugs on neuronal cholesterol levels and neuronal survival were measured. Immunoblots were used to determine the effects of simvastatin or squalestatin on the distribution of the PAF receptor and an enzyme linked immunoassay was used to quantify the amounts of PAF receptor. Results PAF killed primary neurons in a dose-dependent manner. Pre-treatment with simvastatin or squalestatin reduced neuronal cholesterol and increased the survival of PAF-treated neurons. Neuronal survival was increased 50% by 100 nM simvastatin, or 20 nM squalestatin. The addition of mevalonate restored cholesterol levels, and reversed the protective effect of simvastatin. Simvastatin or squalestatin did not affect the amounts of the PAF receptor but did cause it to disperse from within lipid rafts. Conclusion Treatment of neurons with cholesterol synthesis inhibitors including simvastatin and squalestatin protected neurons against PAF. Treatment caused a percentage of the PAF receptors to disperse from cholesterol-sensitive domains. These results raise the possibility that the effects of statins on neurodegenerative disease are, at least in part, due to desensitisation of neurons to PAF. PMID:17233902

  11. Acute lower motor neuron syndrome and spinal cord gray matter hyperintensities in HIV infection

    PubMed Central

    Wilson, Michael R.; Chad, David A.; Venna, Nagagopal

    2015-01-01

    Objective: To describe a novel manifestation of lower motor neuron disease in patients with well-controlled HIV infection. Methods: A retrospective study was performed to identify HIV-positive individuals with acute, painful lower motor neuron diseases. Results: Six patients were identified with HIV and lower motor neuron disease. Two patients met the inclusion criteria of well-controlled, chronic HIV infection and an acute, painful, unilateral lower motor neuron paralytic syndrome affecting the distal portion of the upper limb. These patients had segmental T2-hyperintense lesions in the central gray matter of the cervical spinal cord on MRI. One patient stabilized and the second patient improved with immunomodulatory therapy. Conclusions: This newly described syndrome expands the clinical spectrum of lower motor neuron diseases in HIV. PMID:26015990

  12. Neuronal damage and calcium accumulation following transient cerebral ischemia in the rat

    SciTech Connect

    Araki, T.; Inoue, T.; Kato, H.; Kogure, K.; Murakami, M. )

    1990-06-01

    The purpose of this study was to examine the distribution of neuronal damage following transient cerebral ischemia in the rat model of four-vessel occlusion utilizing light microscopy as well as {sup 45}Ca-autoradiography. Transient ischemia was induced for 30 min. The animals were allowed to survive for 7 d after ischemia. In the animals subjected to ischemia, the most frequently and seriously damaged areas were the paramedian region of hippocampus, the hippocampal CA1 sector, and the dorsolateral part of striatum, followed by the inferior colliculus, the substantia nigra, the frontal cortex, and the thalamus, which were moderate damaged. Furthermore, the cerebellar Purkinje neurons, the hippocampal CA4 sector, the medial geniculate body, and the hippocampal CA3 sector were slightly affected. {sup 45}Ca-autoradiographyic study also revealed calcium accumulation in the identical sites of ischemic neuronal damage, except for the frontal cortex. Regional cerebral blood flow during 10 min of ischemia was severely decreased in selectively vulnerable areas. The blood flow in the medial geniculate body, the substantia nigra, the inferior colliculus, and the cerebellum was less pronounced than that in the selectively vulnerable areas. The present study demonstrates that transient cerebral ischemia can produce significant neuronal damage not only in the selectively vulnerable regions, but also in the brainstem.

  13. Evidence of neuronal oxidative damage in Alzheimer's disease.

    PubMed Central

    Good, P. F.; Werner, P.; Hsu, A.; Olanow, C. W.; Perl, D. P.

    1996-01-01

    Oxidative stress has been proposed as a pathogenetic mechanism in Alzheimer's disease. One mechanism of oxidative damage is the nitration of tyrosine residues in proteins, mediated by peroxynitrite breakdown. Peroxynitrite, a reaction product of nitric oxide and superoxide radicals, has been implicated in N-methyl-D-aspartate receptor-mediated excitotoxic damage. Reported evidence of oxidative stress in Alzheimer's disease includes increased iron, alterations in protective enzymes, and markers of oxidative damage to proteins and lipids. In this report, we demonstrate the presence of nitrotyrosine in neurofibrillary tangles of Alzheimer's disease. Nitrotyrosine was not detected in controls lacking neurofibrillary tangles. Immunolabeling was demonstrated to be specific nitrotyrosine in a series of control experiments. These observations link oxidative stress with a key pathological lesion of Alzheimer's disease, the neurofibrillary tangle, and demonstrate a pathogenetic mechanism in common with the other major neurodegenerative diseases of aging, Parkinson's disease and amyotrophic lateral sclerosis. These findings further implicate nitric oxide expression and excitotoxicity in the pathogenesis of cell death in Alzheimer's disease. Images Figure 1 Figure 2 PMID:8686745

  14. Single-stranded DNA as an immunohistochemical marker of neuronal damage in human brain: an analysis of autopsy material with regard to the cause of death.

    PubMed

    Michiue, Tomomi; Ishikawa, Takaki; Quan, Li; Li, Dong-Ri; Zhao, Dong; Komatsu, Ayumi; Zhu, Bao-Li; Maeda, Hitoshi

    2008-07-01

    Single-stranded DNA (ssDNA) is a marker of apoptosis and programmed cell death, which appears prior to DNA fragmentation during delayed neuronal death. The present study investigated the immunohistochemical distribution of ssDNA in the brain to investigate apoptotic neuronal damage with regard to the cause of death in medicolegal autopsy cases (n=305). Neuronal immunopositivity for ssDNA was globally detected in the brain, independent of the age, gender of subjects and postmortem interval, and depended on the cause of death. Higher positivity was typically found in the pallidum for delayed brain injury death and fatal carbon monoxide intoxication, and in the cerebral cortex, pallidum and substantia nigra for drug intoxication. For mechanical asphyxiation, a high positivity was detected in the cerebral cortex and pallidum, while the positivity was low in the substantia nigra. The neuronal ssDNA increased during the survival period within about 24h at each site, depending on the type of brain injury, and in the substantia nigra for other blunt injuries. The neuronal positivity was usually lower for drowning and acute ischemic disease. Topographical analysis of ssDNA-positive neurons may contribute to investigating the cause of brain damage and survival period after a fatal insult. PMID:18462896

  15. Acute selective ablation of rat insulin promoter-expressing (RIPHER) neurons defines their orexigenic nature

    PubMed Central

    Rother, Eva; Belgardt, Bengt F.; Tsaousidou, Eva; Hampel, Brigitte; Waisman, Ari; Myers, Martin G.; Brüning, Jens C.

    2012-01-01

    Rat insulin promoter (RIP)-expressing neurons in the hypothalamus control body weight and energy homeostasis. However, genetic approaches to study the role of these neurons have been limited by the fact that RIP expression is predominantly found in pancreatic β-cells, which impedes selective targeting of neurons. To define the function of hypothalamic RIP-expressing neurons, we set out to acutely and selectively eliminate them via diphtheria toxin-mediated ablation. Therefore, the diphtheria toxin receptor transgene was specifically expressed upon RIP-specific Cre recombination using a RIP-Cre line first described by Herrera (RIPHER-Cre) [Herrera PL (2000) Development 127:2317–2322]. Using proopiomelanocortin–expressing cells located in the arcuate nucleus of the hypothalamus and in the pituitary gland as a model, we established a unique protocol of intracerebroventricular application of diphtheria toxin to efficiently ablate hypothalamic cells with no concomitant effect on pituitary proopiomelanocortin–expressing corticotrophs in the mouse. Using this approach to ablate RIPHER neurons in the brain, but not in the pancreas, resulted in decreased food intake and loss of body weight and fat mass. In addition, ablation of RIPHER neurons caused increased c-Fos immunoreactivity of neurons in the paraventricular nucleus (PVN) of the hypothalamus. Moreover, transsynaptic tracing of RIPHER neurons revealed labeling of neurons located in the PVN and dorsomedial hypothalamic nucleus. Thus, our experiments indicate that RIPHER neurons inhibit anorexigenic neurons in the PVN, revealing a basic orexigenic nature of these cells. PMID:23064638

  16. GVS-111 prevents oxidative damage and apoptosis in normal and Down's syndrome human cortical neurons.

    PubMed

    Pelsman, Alejandra; Hoyo-Vadillo, Carlos; Gudasheva, Tatiana A; Seredenin, Sergei B; Ostrovskaya, Rita U; Busciglio, Jorge

    2003-05-01

    The neuroprotective activity of a novel N-acylprolyl-containing dipeptide analog of the nootropic 2-oxo-1-pyrrolidine acetamide (Piracetam) designated as GVS-111 (DVD-111/Noopept) was tested in two in vitro models of neuronal degeneration mediated by oxidative stress: normal human cortical neurons treated with H(2)O(2), and Down's syndrome (DS) cortical neurons. Incubation of normal cortical neurons with 50 microM H(2)O(2) for 1h resulted in morphological and structural changes consistent with neuronal apoptosis and in the degeneration of more than 60% of the neurons present in the culture. GVS-111 significantly increased neuronal survival after H(2)O(2)-treatment displaying a dose-dependent neuroprotective activity from 10nM to 100 microM, and an IC(50) value of 1.21+/-0.07 microM. GVS-111 inhibited the accumulation of intracellular free radicals and lipid peroxidation damage in neurons treated with H(2)O(2) or FeSO(4), suggesting an antioxidant mechanism of action. GVS-111 exhibited significantly higher neuroprotection compared to the standard cognition enhancer Piracetam, or to the antioxidants Vitamin E, propyl gallate and N-tert-butyl-2-sulpho-phenylnitrone (s-PBN). In DS cortical cultures, chronic treatment with GVS-111 significantly reduced the appearance of degenerative changes and enhanced neuronal survival. The results suggest that the neuroprotective effect of GVS-111 against oxidative damage and its potential nootropic activity may present a valuable therapeutic combination for the treatment of mental retardation and chronic neurodegenerative disorders. PMID:12711349

  17. Oenanthe Javanica Extract Protects Against Experimentally Induced Ischemic Neuronal Damage via its Antioxidant Effects

    PubMed Central

    Park, Joon Ha; Cho, Jeong Hwi; Kim, In Hye; Ahn, Ji Hyeon; Lee, Jae-Chul; Chen, Bai Hui; Shin, Bich-Na; Tae, Hyun-Jin; Yoo, Ki-Yeon; Hong, SeongKweon; Kang, Il Jun; Won, Moo-Ho; Kim, Jong-Dai

    2015-01-01

    Background: Water dropwort (Oenanthe javanica) as a popular traditional medicine in Asia shows various biological properties including antioxidant activity. In this study, we firstly examined the neuroprotective effect of Oenanthe javanica extract (OJE) in the hippocampal cornus ammonis 1 region (CA1 region) of the gerbil subjected to transient cerebral ischemia. Methods: Gerbils were established by the occlusion of common carotid arteries for 5 min. The neuroprotective effect of OJE was estimated by cresyl violet staining. In addition, 4 antioxidants (copper, zinc superoxide dismutase [SOD], manganese SOD, catalase, and glutathione peroxidase) immunoreactivities were investigated by immunohistochemistry. Results: Pyramidal neurons in the CA1 region showed neuronal death at 5 days postischemia; at this point in time, all antioxidants immunoreactivities disappeared in CA1 pyramidal neurons and showed in many nonpyramidal cells. Treatment with 200 mg/kg, not 100 mg/kg, OJE protected CA1 pyramidal neurons from ischemic damage. In addition, 200 mg/kg OJE treatment increased or maintained antioxidants immunoreactivities. Especially, among the antioxidants, glutathione peroxidase immunoreactivity was effectively increased in the CA1 pyramidal neurons of the OJE-treated sham-operated and ischemia-operated groups. Conclusion: Our present results indicate that treatment with OJE can protect neurons from transient ischemic damage and that the neuroprotective effect may be closely associated with increased or maintained intracellular antioxidant enzymes by OJE. PMID:26521793

  18. PARP-1 modulates amyloid beta peptide-induced neuronal damage.

    PubMed

    Martire, Sara; Fuso, Andrea; Rotili, Dante; Tempera, Italo; Giordano, Cesare; De Zottis, Ivana; Muzi, Alessia; Vernole, Patrizia; Graziani, Grazia; Lococo, Emanuela; Faraldi, Martina; Maras, Bruno; Scarpa, Sigfrido; Mosca, Luciana; d'Erme, Maria

    2013-01-01

    Amyloid beta peptide (Aβ) causes neurodegeneration by several mechanisms including oxidative stress, which is known to induce DNA damage with the consequent activation of poly (ADP-ribose) polymerase (PARP-1). To elucidate the role of PARP-1 in the neurodegenerative process, SH-SY5Y neuroblastoma cells were treated with Aβ25-35 fragment in the presence or absence of MC2050, a new PARP-1 inhibitor. Aβ25-35 induces an enhancement of PARP activity which is prevented by cell pre-treatment with MC2050. These data were confirmed by measuring PARP-1 activity in CHO cells transfected with amylod precursor protein and in vivo in brains specimens of TgCRND8 transgenic mice overproducing the amyloid peptide. Following Aβ25-35 exposure a significant increase in intracellular ROS was observed. These data were supported by the finding that Aβ25-35 induces DNA damage which in turn activates PARP-1. Challenge with Aβ25-35 is also able to activate NF-kB via PARP-1, as demonstrated by NF-kB impairment upon MC2050 treatment. Moreover, Aβ25-35 via PARP-1 induces a significant increase in the p53 protein level and a parallel decrease in the anti-apoptotic Bcl-2 protein. These overall data support the hypothesis of PARP-1 involvment in cellular responses induced by Aβ and hence a possible rationale for the implication of PARP-1 in neurodegeneration is discussed. PMID:24086258

  19. PARP-1 Modulates Amyloid Beta Peptide-Induced Neuronal Damage

    PubMed Central

    Martire, Sara; Fuso, Andrea; Rotili, Dante; Tempera, Italo; Giordano, Cesare; De Zottis, Ivana; Muzi, Alessia; Vernole, Patrizia; Graziani, Grazia; Lococo, Emanuela; Faraldi, Martina; Maras, Bruno; Scarpa, Sigfrido; Mosca, Luciana; d'Erme, Maria

    2013-01-01

    Amyloid beta peptide (Aβ) causes neurodegeneration by several mechanisms including oxidative stress, which is known to induce DNA damage with the consequent activation of poly (ADP-ribose) polymerase (PARP-1). To elucidate the role of PARP-1 in the neurodegenerative process, SH-SY5Y neuroblastoma cells were treated with Aβ25–35 fragment in the presence or absence of MC2050, a new PARP-1 inhibitor. Aβ25–35 induces an enhancement of PARP activity which is prevented by cell pre-treatment with MC2050. These data were confirmed by measuring PARP-1 activity in CHO cells transfected with amylod precursor protein and in vivo in brains specimens of TgCRND8 transgenic mice overproducing the amyloid peptide. Following Aβ25–35 exposure a significant increase in intracellular ROS was observed. These data were supported by the finding that Aβ25–35 induces DNA damage which in turn activates PARP-1. Challenge with Aβ25–35 is also able to activate NF-kB via PARP-1, as demonstrated by NF-kB impairment upon MC2050 treatment. Moreover, Aβ25–35 via PARP-1 induces a significant increase in the p53 protein level and a parallel decrease in the anti-apoptotic Bcl-2 protein. These overall data support the hypothesis of PARP-1 involvment in cellular responses induced by Aβ and hence a possible rationale for the implication of PARP-1 in neurodegeneration is discussed. PMID:24086258

  20. Mitophagy of damaged mitochondria occurs locally in distal neuronal axons and requires PINK1 and Parkin

    PubMed Central

    Ashrafi, Ghazaleh; Schlehe, Julia S.; LaVoie, Matthew J.

    2014-01-01

    To minimize oxidative damage to the cell, malfunctioning mitochondria need to be removed by mitophagy. In neuronal axons, mitochondrial damage may occur in distal regions, far from the soma where most lysosomal degradation is thought to occur. In this paper, we report that PINK1 and Parkin, two Parkinson’s disease–associated proteins, mediate local mitophagy of dysfunctional mitochondria in neuronal axons. To reduce cytotoxicity and mimic physiological levels of mitochondrial damage, we selectively damaged a subset of mitochondria in hippocampal axons. Parkin was rapidly recruited to damaged mitochondria in axons followed by formation of LC3-positive autophagosomes and LAMP1-positive lysosomes. In PINK1−/− axons, damaged mitochondria did not accumulate Parkin and failed to be engulfed in autophagosomes. Similarly, initiation of mitophagy was blocked in Parkin−/− axons. Our findings demonstrate that the PINK1–Parkin-mediated pathway is required for local mitophagy in distal axons in response to focal damage. Local mitophagy likely provides rapid neuroprotection against oxidative stress without a requirement for retrograde transport to the soma. PMID:25154397

  1. Neuronal NOS and cyclooxygenase-2 contribute to DNA damage in a mouse model of Parkinson disease.

    PubMed

    Hoang, Tuan; Choi, Dong-Kug; Nagai, Makiko; Wu, Du-Chu; Nagata, Tetsuya; Prou, Delphine; Wilson, Glenn L; Vila, Miquel; Jackson-Lewis, Vernice; Dawson, Valina L; Dawson, Ted M; Chesselet, Marie-Françoise; Przedborski, Serge

    2009-10-01

    DNA damage is a proposed pathogenic factor in neurodegenerative disorders such as Parkinson disease. To probe the underpinning mechanism of such neuronal perturbation, we sought to produce an experimental model of DNA damage. We thus first assessed DNA damage by in situ nick translation and emulsion autoradiography in the mouse brain after administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP; 4 x 20 mg/kg, ip, every 2 h), a neurotoxin known to produce a model of Parkinson disease. Here we show that DNA strand breaks occur in vivo in this mouse model of Parkinson disease with kinetics and a topography that parallel the degeneration of substantia nigra neurons, as assessed by FluoroJade labeling. Previously, nitric oxide synthase and cyclooxygenase-2 (Cox-2) were found to modulate MPTP-induced dopaminergic neuronal death. We thus assessed the contribution of these enzymes to DNA damage in mice lacking neuronal nitric oxide synthase (nNOS), inducible nitric oxide synthase (iNOS), or Cox-2. We found that the lack of Cox-2 and nNOS activities but not of iNOS activity attenuated MPTP-related DNA damage. We also found that not only nuclear, but also mitochondrial, DNA is a target for the MPTP insult. These results suggest that the loss of genomic integrity can be triggered by the concerted actions of nNOS and Cox-2 and provide further support to the view that DNA damage may contribute to the neurodegenerative process in Parkinson disease. PMID:19616617

  2. Oral Resveratrol Reduces Neuronal Damage in a Model of Multiple Sclerosis

    PubMed Central

    Shindler, Kenneth S.; Ventura, Elvira; Dutt, Mahasweta; Elliott, Peter; Fitzgerald, Denise C.; Rostami, Abdolmohamad

    2012-01-01

    Background Neuronal loss in multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE), correlates with permanent neurological dysfunction. Current MS therapies have limited ability to prevent neuronal damage. Methods We examined whether oral therapy with SRT501, a pharmaceutical-grade formulation of resveratrol, reduces neuronal loss during relapsing/remitting EAE. Resveratrol activates SIRT1, an NAD+-dependent deacetylase that promotes mitochondrial function. Results Oral SRT501 prevented neuronal loss during optic neuritis, an inflammatory optic nerve lesion in MS and EAE. SRT501 also suppressed neurological dysfunction during EAE remission, and spinal cords from SRT501-treated mice had significantly higher axonal density than vehicle-treated mice. Similar neuroprotection was mediated by SRT1720, another SIRT1-activating compound; and sirtinol, a SIRT1 inhibitor, attenuated SRT501 neuroprotective effects. SIRT1 activators did not prevent inflammation. Conclusions These studies demonstrate SRT501 attenuates neuronal damage and neurological dysfunction in EAE by a mechanism involving SIRT1 activation. SIRT1 activators are a potential oral therapy in MS. PMID:21107122

  3. Brain capacity for repair of oxidatively damaged DNA and preservation of neuronal function.

    PubMed

    Englander, Ella W

    2008-01-01

    Accumulation of oxidative DNA damage in the human brain has been implicated in etiologies of post-traumatic and age-associated declines in neuronal function. In neurons, because of high metabolic rates and prolonged life span, exposure to free radicals is intense and risk for accumulation of damaged DNA is amplified. While data indicate that the brain is equipped to repair nuclear and mitochondrial DNA, it is unclear whether repair is executed by distinct subsets of the DNA-repair machinery. Likewise, there are no firm assessments of brain capacity for accurate DNA repair under normal and more so compromised conditions. Consequently, the scope of DNA repair in the brain and the impact of resolution of oxidative lesions on neuronal survival and function remain largely unknown. This review considers evidences for brain levels and activities of the base excision repair (BER) pathway in the context of newly available, comprehensive in situ hybridization analyses of genes encoding repair enzymes. These analyses suggest that not all subsets of BER are equally represented in the brain. Because BER is the major repair process for oxidatively damaged DNA, to what extent parsimonious BER may contribute to development of neuronal dysfunction and brain injury under compromised conditions, is discussed. PMID:18374390

  4. Iron Oxide Nanoparticles Induce Dopaminergic Damage: In vitro Pathways and In Vivo Imaging Reveals Mechanism of Neuronal Damage.

    PubMed

    Imam, Syed Z; Lantz-McPeak, Susan M; Cuevas, Elvis; Rosas-Hernandez, Hector; Liachenko, Serguei; Zhang, Yongbin; Sarkar, Sumit; Ramu, Jaivijay; Robinson, Bonnie L; Jones, Yvonne; Gough, Bobby; Paule, Merle G; Ali, Syed F; Binienda, Zbigniew K

    2015-10-01

    Various iron-oxide nanoparticles have been in use for a long time as therapeutic and imaging agents and for supplemental delivery in cases of iron-deficiency. While all of these products have a specified size range of ∼ 40 nm and above, efforts are underway to produce smaller particles, down to ∼ 1 nm. Here, we show that after a 24-h exposure of SHSY-5Y human neuroblastoma cells to 10 μg/ml of 10 and 30 nm ferric oxide nanoparticles (Fe-NPs), cellular dopamine content was depleted by 68 and 52 %, respectively. Increases in activated tyrosine kinase c-Abl, a molecular switch induced by oxidative stress, and neuronal α-synuclein expression, a protein marker associated with neuronal injury, were also observed (55 and 38 % percent increases, respectively). Inhibition of cell-proliferation, significant reductions in the number of active mitochondria, and a dose-dependent increase in reactive oxygen species (ROS) were observed in neuronal cells. Additionally, using a rat in vitro blood-brain barrier (BBB) model, a dose-dependent increase in ROS accompanied by increased fluorescein efflux demonstrated compromised BBB integrity. To assess translational implications, in vivo Fe-NP-induced neurotoxicity was determined using in vivo MRI and post-mortem neurochemical and neuropathological correlates in adult male rats after exposure to 50 mg/kg of 10 nm Fe-NPs. Significant decrease in T 2 values was observed. Dynamic observations suggested transfer and retention of Fe-NPs from brain vasculature into brain ventricles. A significant decrease in striatal dopamine and its metabolites was also observed, and neuropathological correlates provided additional evidence of significant nerve cell body and dopaminergic terminal damage as well as damage to neuronal vasculature after exposure to 10 nm Fe-NPs. These data demonstrate a neurotoxic potential of very small size iron nanoparticles and suggest that use of these ferric oxide nanoparticles may result in neurotoxicity, thereby

  5. Neuroprotective Effects of Agmatine Against Cell Damage Caused by Glucocorticoids in Cultured Rat Hippocampal Neurons

    PubMed Central

    Zhu, M.-Y.; Wang, W.-P.; Bissette, G.

    2010-01-01

    In the present study the neuroprotective effects of agmatine against neuronal damage caused by glucocorticoids were examined in cultured rat hippocampal neurons. Spectrophotometric measurements of lactate dehydrogenase activities, β-tubulin III immunocytochemical staining, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP) nick-end-labeling assay (TUNEL) labeling and caspase-3 assays were carried out to detect cell damage or possible involved mechanisms. Our results show that dexamethasone and corticosterone produced a concentration-dependent increase of lactate dehydrogenase release in 12-day hippocampal cultures. Addition of 100 μM agmatine into media prevented the glucocorticoid-induced increase of lactate dehydrogenase release, an effect also shared with the specific N-methyl-d-aspartate receptor antagonist MK801 and glucocorticoid receptor antagonists mifepristone and spironolactone. Arcaine, an analog of agmatine with similar structure as agmatine, also blocked glucocorticoid-induced increase of lactate dehydrogenase release. Spermine and putrescine, the endogenous polyamine and metabolic products of agmatine without the guanidino moiety of agmatine, have no appreciable effect on glucocorticoid-induced injuries, indicating a structural relevance for this neuroprotection. Immunocytochemical staining with β-tubulin III confirmed the substantial neuronal injuries caused by glucocorticoids and the neuroprotective effects of agmatine against these neuronal injuries. TUNEL labeling demonstrated that agmatine significantly reduced TUNEL-positive cell numbers induced by exposure of cultured neurons to dexamethasone. Moreover, exposure of hippocampal neurons to dexamethasone significantly increased caspase-3 activity, which was inhibited by co-treatment with agmatine. Taken together, these results demonstrate that agmatine can protect cultured hippocampal neurons from glucocorticoid-induced neurotoxicity, through a possible blockade of

  6. Sildenafil Attenuates Inflammation and Oxidative Stress in Pelvic Ganglia Neurons after Bilateral Cavernosal Nerve Damage

    PubMed Central

    Garcia, Leah A.; Hlaing, Su M.; Gutierrez, Richard A.; Sanchez, Maria D.; Kovanecz, Istvan; Artaza, Jorge N.; Ferrini, Monica G.

    2014-01-01

    Erectile dysfunction is a common complication for patients undergoing surgeries for prostate, bladder, and colorectal cancers, due to damage of the nerves associated with the major pelvic ganglia (MPG). Functional re-innervation of target organs depends on the capacity of the neurons to survive and switch towards a regenerative phenotype. PDE5 inhibitors (PDE5i) have been successfully used in promoting the recovery of erectile function after cavernosal nerve damage (BCNR) by up-regulating the expression of neurotrophic factors in MPG. However, little is known about the effects of PDE5i on markers of neuronal damage and oxidative stress after BCNR. This study aimed to investigate the changes in gene and protein expression profiles of inflammatory, anti-inflammatory cytokines and oxidative stress related-pathways in MPG neurons after BCNR and subsequent treatment with sildenafil. Our results showed that BCNR in Fisher-344 rats promoted up-regulation of cytokines (interleukin- 1 (IL-1) β, IL-6, IL-10, transforming growth factor β 1 (TGFβ1), and oxidative stress factors (Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, Myeloperoxidase (MPO), inducible nitric oxide synthase (iNOS), TNF receptor superfamily member 5 (CD40) that were normalized by sildenafil treatment given in the drinking water. In summary, PDE5i can attenuate the production of damaging factors and can up-regulate the expression of beneficial factors in the MPG that may ameliorate neuropathic pain, promote neuroprotection, and favor nerve regeneration. PMID:25264738

  7. Reduced calcium-dependent mitochondrial damage underlies the reduced vulnerability of excitotoxicity-tolerant hippocampal neurons.

    PubMed

    Pivovarova, Natalia B; Stanika, Ruslan I; Watts, Charlotte A; Brantner, Christine A; Smith, Carolyn L; Andrews, S Brian

    2008-03-01

    In central neurons, over-stimulation of NMDA receptors leads to excessive mitochondrial calcium accumulation and damage, which is a critical step in excitotoxic death. This raises the possibility that low susceptibility to calcium overload-induced mitochondrial damage might characterize excitotoxicity-resistant neurons. In this study, we have exploited two complementary models of preconditioning-induced excitotoxicity resistance to demonstrate reduced calcium-dependent mitochondrial damage in NMDA-tolerant hippocampal neurons. We have further identified adaptations in mitochondrial calcium handling that account for enhanced mitochondrial integrity. In both models, enhanced tolerance was associated with improved preservation of mitochondrial membrane potential and structure. In the first model, which exhibited modest neuroprotection, mitochondria-dependent calcium deregulation was delayed, even though cytosolic and mitochondrial calcium loads were quantitatively unchanged, indicating that enhanced mitochondrial calcium capacity accounts for reduced injury. In contrast, the second model, which exhibited strong neuroprotection, displayed further delayed calcium deregulation and reduced mitochondrial damage because downregulation of NMDA receptor surface expression depressed calcium loading. Reducing calcium entry also modified the chemical composition of the calcium-buffering precipitates that form in calcium-loaded mitochondria. It thus appears that reduced mitochondrial calcium loading is a major factor underlying the robust neuroprotection seen in highly tolerant cells. PMID:18036152

  8. Cardiac troponins as indicators of acute myocardial damage in dogs.

    PubMed

    Burgener, Iwan A; Kovacevic, Alan; Mauldin, G Neal; Lombard, Christophe W

    2006-01-01

    Cardiac troponin I (cTnI) and T (cTnT) have a high sequence homology across phyla and are sensitive and specific markers of myocardial damage. The purpose of this study was to evaluate the Cardiac Reader, a human point-of-care system for the determination of cTnT and myoglobin, and the Abbott Axsym System for the determination of cTnI and creatine kinase isoenzyme MB (CK-MB) in healthy dogs and in dogs at risk for acute myocardial damage because of gastric dilatation-volvulus (GDV) and blunt chest trauma (BCT). In healthy dogs (n = 56), cTnI was below detection limits (<0.1 microg/L) in 35 of 56 dogs (reference range 0-0.7 microg/L), and cTnT was not measurable (<0.05 ng/mL) in all but 1 dog. At presentation, cTnI, CK-MB, myoglobin, and lactic acid were all significantly higher in dogs with GDV (n = 28) and BCT (n = 8) than in control dogs (P < .001), but cTnT was significantly higher only in dogs with BCT (P = .033). Increased cTnI or cTnT values were found in 26 of 28 (highest values 1.1-369 microg/L) and 16 of 28 dogs (0.1-1.7 ng/mL) with GDV, and in 6 of 8 (2.3-82.4 microg/L) and 3 of 8 dogs (0.1-0.29 ng/mL) with BCT, respectively. In dogs suffering from GDV, cTnI and cTnT increased further within the first 48 hours (P < .001). Increased cardiac troponins suggestive of myocardial damage occurred in 93% of dogs with GDV and 75% with BCT. cTnI appeared more sensitive, but cTnT may be a negative prognostic indicator in GDV. Both systems tested seemed applicable for the measurement of canine cardiac troponins, with the Cardiac Reader particularly suitable for use in emergency settings. PMID:16594583

  9. Acute Stimulation of Transplanted Neurons Improves Motoneuron Survival, Axon Growth, and Muscle Reinnervation

    PubMed Central

    Grumbles, Robert M.; Liu, Yang; Thomas, Christie M.; Wood, Patrick M.

    2013-01-01

    Abstract Few options exist for treatment of pervasive motoneuron death after spinal cord injury or in neurodegenerative diseases such as amyotrophic lateral sclerosis. Local transplantation of embryonic motoneurons into an axotomized peripheral nerve is a promising approach to arrest the atrophy of denervated muscles; however, muscle reinnervation is limited by poor motoneuron survival. The aim of the present study was to test whether acute electrical stimulation of transplanted embryonic neurons promotes motoneuron survival, axon growth, and muscle reinnervation. The sciatic nerve of adult Fischer rats was transected to mimic the widespread denervation seen after disease or injury. Acutely dissociated rat embryonic ventral spinal cord cells were transplanted into the distal tibial nerve stump as a neuron source for muscle reinnervation. Immediately post-transplantation, the cells were stimulated at 20 Hz for 1 h. Other groups were used to control for the cell transplantation and stimulation. When neurons were stimulated acutely, there were significantly more neurons, including cholinergic neurons, 10 weeks after transplantation. This led to enhanced numbers of myelinated axons, reinnervation of more muscle fibers, and more medial and lateral gastrocnemius muscles were functionally connected to the transplant. Reinnervation reduced muscle atrophy significantly. These data support the concept that electrical stimulation rescues transplanted motoneurons and facilitates muscle reinnervation. PMID:23544978

  10. Electrophysiology of Hypothalamic Magnocellular Neurons In vitro: A Rhythmic Drive in Organotypic Cultures and Acute Slices

    PubMed Central

    Israel, Jean-Marc; Oliet, Stéphane H.; Ciofi, Philippe

    2016-01-01

    Hypothalamic neurohormones are released in a pulsatile manner. The mechanisms of this pulsatility remain poorly understood and several hypotheses are available, depending upon the neuroendocrine system considered. Among these systems, hypothalamo-neurohypophyseal magnocellular neurons have been early-considered models, as they typically display an electrical activity consisting of bursts of action potentials that is optimal for the release of boluses of the neurohormones oxytocin and vasopressin. The cellular mechanisms underlying this bursting behavior have been studied in vitro, using either acute slices of the adult hypothalamus, or organotypic cultures of neonatal hypothalamic tissue. We have recently proposed, from experiments in organotypic cultures, that specific central pattern generator networks, upstream of magnocellular neurons, determine their bursting activity. Here, we have tested whether a similar hypothesis can be derived from in vitro experiments in acute slices of the adult hypothalamus. To this aim we have screened our electrophysiological recordings of the magnocellular neurons, previously obtained from acute slices, with an analysis of autocorrelation of action potentials to detect a rhythmic drive as we recently did for organotypic cultures. This confirmed that the bursting behavior of magnocellular neurons is governed by central pattern generator networks whose rhythmic drive, and thus probably integrity, is however less satisfactorily preserved in the acute slices from adult brains. PMID:27065780

  11. Nanosize Titanium Dioxide Stimulates Reactive Oxygen Species in Brain Microglia and Damages Neurons in Vitro

    PubMed Central

    Long, Thomas C.; Tajuba, Julianne; Sama, Preethi; Saleh, Navid; Swartz, Carol; Parker, Joel; Hester, Susan; Lowry, Gregory V.; Veronesi, Bellina

    2007-01-01

    Background Titanium dioxide is a widely used nanomaterial whose photo-reactivity suggests that it could damage biological targets (e.g., brain) through oxidative stress (OS). Objectives Brain cultures of immortalized mouse microglia (BV2), rat dopaminergic (DA) neurons (N27), and primary cultures of embryonic rat striatum, were exposed to Degussa P25, a commercially available TiO2 nanomaterial. Physical properties of P25 were measured under conditions that paralleled biological measures. Findings P25 rapidly aggregated in physiological buffer (800–1,900 nm; 25°C) and exposure media (~ 330 nm; 37°C), and maintained a negative zeta potential in both buffer (–12.2 ± 1.6 mV) and media (–9.1 ± 1.2 mV). BV2 microglia exposed to P25 (2.5–120 ppm) responded with an immediate and prolonged release of reactive oxygen species (ROS). Hoechst nuclear stain was reduced after 24-hr (≥100 ppm) and 48-hr (≥2.5 ppm) exposure. Microarray analysis on P25-exposed BV2 microglia indicated up-regulation of inflammatory, apoptotic, and cell cycling pathways and down-regulation of energy metabolism. P25 (2.5–120 ppm) stimulated increases of intracellular ATP and caspase 3/7 activity in isolated N27 neurons (24–48 hr) but did not produce cytotoxicity after 72-hr exposure. Primary cultures of rat striatum exposed to P25 (5 ppm) showed a reduction of immunohistochemically stained neurons and microscopic evidence of neuronal apoptosis after 6-hr exposure. These findings indicate that P25 stimulates ROS in BV2 microglia and is nontoxic to isolated N27 neurons. However, P25 rapidly damages neurons at low concentrations in complex brain cultures, plausibly though microglial generated ROS. PMID:18007996

  12. Secretions from placenta, after hypoxia/reoxygenation, can damage developing neurones of brain under experimental conditions.

    PubMed

    Curtis, Daniel J; Sood, Aman; Phillips, Tom J; Leinster, Veronica H L; Nishiguchi, Akihiro; Coyle, Christopher; Lacharme-Lora, Lizeth; Beaumont, Oliver; Kemp, Helena; Goodall, Roberta; Cornes, Leila; Giugliano, Michele; Barone, Rocco A; Matsusaki, Michiya; Akashi, Mitsuru; Tanaka, Hiroyoshi Y; Kano, Mitsunobu; McGarvey, Jennifer; Halemani, Nagaraj D; Simon, Katja; Keehan, Robert; Ind, William; Masters, Tracey; Grant, Simon; Athwal, Sharan; Collett, Gavin; Tannetta, Dionne; Sargent, Ian L; Scull-Brown, Emma; Liu, Xun; Aquilina, Kristian; Cohen, Nicki; Lane, Jon D; Thoresen, Marianne; Hanley, Jon; Randall, Andrew; Case, C Patrick

    2014-11-01

    Some psychiatric diseases in children and young adults are thought to originate from adverse exposures during foetal life, including hypoxia and hypoxia/reoxygenation. The mechanism is not understood. Several authors have emphasised that the placenta is likely to play an important role as the key interface between mother and foetus. Here we have explored whether a first trimester human placenta or model barrier of primary human cytotrophoblasts might secrete factors, in response to hypoxia or hypoxia/reoxygenation, that could damage neurones. We find that the secretions in conditioned media caused an increase of [Ca(2+)]i and mitochondrial free radicals and a decrease of dendritic lengths, branching complexity, spine density and synaptic activity in dissociated neurones from embryonic rat cerebral cortex. There was altered staining of glutamate and GABA receptors. We identify glutamate as an active factor within the conditioned media and demonstrate a specific release of glutamate from the placenta/cytotrophoblast barriers invitro after hypoxia or hypoxia/reoxygenation. Injection of conditioned media into developing brains of P4 rats reduced the numerical density of parvalbumin-containing neurones in cortex, hippocampus and reticular nucleus, reduced immunostaining of glutamate receptors and altered cellular turnover. These results show that the placenta is able to release factors, in response to altered oxygen, that can damage developing neurones under experimental conditions. PMID:24818543

  13. Carvedilol promotes neurological function, reduces bone loss and attenuates cell damage after acute spinal cord injury in rats.

    PubMed

    Liu, Da; Huang, Ying; Li, Bin; Jia, Changqing; Liang, Feng; Fu, Qin

    2015-02-01

    Acute spinal cord injury (SCI) leads to permanent functional deficits via mechanical injury and secondary mechanisms, but the therapeutic strategy for SCI is limited. Carvedilol has been shown to possess multiple biological and pharmacological properties. The of the present study was to investigate the possible protective effect of carvedilol in SCI rats. An acute SCI rat model was established and neurological function was tested. After carvedilol (10 mg/kg, oral gavage) treatment for 21 days, the status of osteoporosis, neuron damage, astrocyte activation, inflammation, oxidative stress and apoptosis were evaluated in rats. Carvedilol significantly improved locomotor activity that was decreased by SCI. In addition, carvedilol promoted bone growth by regulating the expression of nuclear factor-κB ligand (receptor activator of nuclear factor-κB ligand; RANKL) and osteoprotegerin (OPG), inactivating osteoclasts and thereby increasing bone mineral density in tibias. In addition, carvedilol reduced SCI-induced neural damage, increased neuron number and reduced astrocyte activation in the spinal cord. Furthermore, the production and mRNA expression of tumour necrosis factor-α, interleukin (IL)-1β and IL-6 were significantly reduced, reduced glutathione content and superoxide dismutase activity were markedly increased and malondialdehyde content was markedly decreased in the spinal cords of carvedilol-treated rats. These results indicate that carvedilol exhibits anti-inflammatory and anti-oxidative effects in SCI rats. In addition, the expression of Fas and Fas ligand was reduced by carvedilol treatment, which, in turn, reduced cleaved caspase 3 expression and finally decreased the number of apoptotic cells in the spinal cord. In conclusion, carvedilol promotes neurological function, reduces bone loss and attenuates cell damage after acute SCI in rats. PMID:25424914

  14. The Acute Phase of Mild Traumatic Brain Injury Is Characterized by a Distance-Dependent Neuronal Hypoactivity

    PubMed Central

    Johnstone, Victoria P.A.; Shultz, Sandy R.; Yan, Edwin B.; O'Brien, Terence J.

    2014-01-01

    Abstract The consequences of mild traumatic brain injury (TBI) on neuronal functionality are only now being elucidated. We have now examined the changes in sensory encoding in the whisker-recipient barrel cortex and the brain tissue damage in the acute phase (24 h) after induction of TBI (n=9), with sham controls receiving surgery only (n=5). Injury was induced using the lateral fluid percussion injury method, which causes a mixture of focal and diffuse brain injury. Both population and single cell neuronal responses evoked by both simple and complex whisker stimuli revealed a suppression of activity that decreased with distance from the locus of injury both within a hemisphere and across hemispheres, with a greater extent of hypoactivity in ipsilateral barrel cortex compared with contralateral cortex. This was coupled with an increase in spontaneous output in Layer 5a, but only ipsilateral to the injury site. There was also disruption of axonal integrity in various regions in the ipsilateral but not contralateral hemisphere. These results complement our previous findings after mild diffuse-only TBI induced by the weight-drop impact acceleration method where, in the same acute post-injury phase, we found a similar depth-dependent hypoactivity in sensory cortex. This suggests a common sequelae of events in both diffuse TBI and mixed focal/diffuse TBI in the immediate post-injury period that then evolve over time to produce different long-term functional outcomes. PMID:24927383

  15. Exercise preconditioning exhibits neuroprotective effects on hippocampal CA1 neuronal damage after cerebral ischemia

    PubMed Central

    Shamsaei, Nabi; Khaksari, Mehdi; Erfani, Sohaila; Rajabi, Hamid; Aboutaleb, Nahid

    2015-01-01

    Recent evidence has suggested the neuroprotective effects of physical exercise on cerebral ischemic injury. However, the role of physical exercise in cerebral ischemia-induced hippocampal damage remains controversial. The aim of the present study was to evaluate the effects of pre-ischemia treadmill training on hippocampal CA1 neuronal damage after cerebral ischemia. Male adult rats were randomly divided into control, ischemia and exercise + ischemia groups. In the exercise + ischemia group, rats were subjected to running on a treadmill in a designated time schedule (5 days per week for 4 weeks). Then rats underwent cerebral ischemia induction through occlusion of common carotids followed by reperfusion. At 4 days after cerebral ischemia, rat learning and memory abilities were evaluated using passive avoidance memory test and rat hippocampal neuronal damage was detected using Nissl and TUNEL staining. Pre-ischemic exercise significantly reduced the number of TUNEL-positive cells and necrotic cell death in the hippocampal CA1 region as compared to the ischemia group. Moreover, pre-ischemic exercise significantly prevented ischemia-induced memory dysfunction. Pre-ischemic exercise mighct prevent memory deficits after cerebral ischemia through rescuing hippocampal CA1 neurons from ischemia-induced degeneration. PMID:26487851

  16. Is nocturnal desaturation a trigger for neuronal damage in chronic obstructive pulmonary disease?

    PubMed

    Alexandre, Francois; Heraud, Nelly; Varray, Alain

    2015-01-01

    Patients with chronic obstructive pulmonary disease (COPD) present many neurological disorders of unknown origin. Although hypoxemia has long been thought to be responsible, several studies have shown evidence of neuronal damage and dysfunction even in non-hypoxemic patients with COPD. Adaptive mechanisms protect the brain from hypoxia: when arterial oxygen tension (PaO2) decreases, the cerebral blood flow (CBF) increases, ensuring continuously adequate oxygen delivery to the brain. However, this mechanism is abolished during non-rapid eye movement (NREM) sleep. Any drop in PaO2 during NREM sleep is therefore not compensated by increased CBF, causing decreased cerebral oxygen delivery with subsequent brain hypoxia. Patients with may therefore be exposed to neuronal damage during this critical time. This mechanism is of vital importance for patients with COPD because of the potentially deleterious cortical effects. Nocturnal desaturation is quite frequent in COPD and affects approximately one out of two patients who are not hypoxemic during wakefulness. Although the prevalence of NREM sleep desaturation has never been specifically assessed in COPD, current data suggest that at least half of the nocturnal desaturation in desaturating patients occurs during NREM sleep. This review presents the rationale for the hypothesis that nocturnal desaturation during NREM sleep promotes neuronal damage and dysfunction in COPD. PMID:25434481

  17. Vigabatrin and carbamazepine have different efficacies in the prevention of status epilepticus induced neuronal damage in the hippocampus and amygdala.

    PubMed

    Pitkänen, A; Tuunanen, J; Halonen, T

    1996-05-01

    The present study compares the efficacy of carbamazepine (20 mg/kg/day) and vigabatrin (250 mg/kg/day) in preventing hippocampal and amygdaloid damage in the perforant pathway stimulation model of status epilepticus in the rat. One group of rats received a combination of the drugs. Drug treatments were started one week before the stimulation and continued for two weeks thereafter. Gallyas silver impregnation and somatostatin immunohistochemistry were used to detect neuronal damage. All drug treatments were equally effective in decreasing the number and severity of seizures during electrical stimulation. In the vigabatrin group, the damage to the hilar somatostatin-immunoreactive (SOM-ir) neurons and hippocampal CA3c pyramidal cells was less severe than in the vehicle (SOM-ir, P < 0.01; CA3c, P < 0.05) and carbamazepine (SOM-ir, P < 0.01; CA3c, P < 0.05) groups. In the carbamazepine and combination groups, the severity of neuronal damage in the hippocampus did not differ from that in vehicle-treated animals. The amygdaloid neurons were not protected by any of the treatments. Our results show that even though vigabatrin and carbamazepine treatments had similar anticonvulsant efficacy during the perforant pathway stimulation, only vigabatrin but not carbamazepine decreased seizure-induced neuronal damage. Vigabatrin decreased neuronal damage in the hippocampus but not in the amygdala. These results demonstrate that different brain regions and neuronal networks may be protected unequally by different anticonvulsants. PMID:8800633

  18. Development and Maturation of Embryonic Cortical Neurons Grafted into the Damaged Adult Motor Cortex

    PubMed Central

    Ballout, Nissrine; Frappé, Isabelle; Péron, Sophie; Jaber, Mohamed; Zibara, Kazem; Gaillard, Afsaneh

    2016-01-01

    Injury to the human central nervous system can lead to devastating consequences due to its poor ability to self-repair. Neural transplantation aimed at replacing lost neurons and restore functional circuitry has proven to be a promising therapeutical avenue. We previously reported in adult rodent animal models with cortical lesions that grafted fetal cortical neurons could effectively re-establish specific patterns of projections and synapses. The current study was designed to provide a detailed characterization of the spatio-temporal in vivo development of fetal cortical transplanted cells within the lesioned adult motor cortex and their corresponding axonal projections. We show here that as early as 2 weeks after grafting, cortical neuroblasts transplanted into damaged adult motor cortex developed appropriate projections to cortical and subcortical targets. Grafted cells initially exhibited characteristics of immature neurons, which then differentiated into mature neurons with appropriate cortical phenotypes where most were glutamatergic and few were GABAergic. All cortical subtypes identified with the specific markers CTIP2, Cux1, FOXP2, and Tbr1 were generated after grafting as evidenced with BrdU co-labeling. The set of data provided here is of interest as it sets biological standards for future studies aimed at replacing fetal cells with embryonic stem cells as a source of cortical neurons. PMID:27536221

  19. Glial degeneration with oxidative damage drives neuronal demise in MPSII disease.

    PubMed

    Zalfa, Cristina; Verpelli, Chiara; D'Avanzo, Francesca; Tomanin, Rosella; Vicidomini, Cinzia; Cajola, Laura; Manara, Renzo; Sala, Carlo; Scarpa, Maurizio; Vescovi, Angelo Luigi; De Filippis, Lidia

    2016-01-01

    Mucopolysaccharidosis type II (MPSII) is a lysosomal storage disorder due to the deficit of the iduronate 2-sulfatase (IDS) enzyme, causing progressive neurodegeneration in patients. Neural stem cells (NSCs) derived from the IDS-ko mouse can recapitulate MPSII pathogenesis in vitro. In differentiating IDS-ko NSCs and in the aging IDS-ko mouse brain, glial degeneration precedes neuronal degeneration. Here we show that pure IDS-ko NSC-derived astrocytes are selectively able to drive neuronal degeneration when cocultured with healthy neurons. This phenotype suggests concurrent oxidative damage with metabolic dysfunction. Similar patterns were observed in murine IDS-ko animals and in human MPSII brains. Most importantly, the mutant phenotype of IDS-ko astrocytes was reversed by low oxygen conditions and treatment with vitamin E, which also reversed the toxic effect on cocultured neurons. Moreover, at very early stages of disease we detected in vivo the development of a neuroinflammatory background that precedes astroglial degeneration, thus suggesting a novel model of MPSII pathogenesis, with neuroinflammation preceding glial degeneration, which is finally followed by neuronal death. This hypothesis is also consistent with the progression of white matter abnormalities in MPSII patients. Our study represents a novel breakthrough in the elucidation of MPSII brain pathogenesis and suggests the antioxidant molecules as potential therapeutic tools to delay MPSII onset and progression. PMID:27512952

  20. Rare Individual Amyloid-β Oligomers Act on Astrocytes to Initiate Neuronal Damage

    PubMed Central

    2014-01-01

    Oligomers of the amyloid-β (Aβ) peptide have been implicated in the neurotoxicity associated with Alzheimer’s disease. We have used single-molecule techniques to examine quantitatively the cellular effects of adding well characterized Aβ oligomers to primary hippocampal cells and hence determine the initial pathway of damage. We found that even picomolar concentrations of Aβ (1–40) and Aβ (1–42) oligomers can, within minutes of addition, increase the levels of intracellular calcium in astrocytes but not in neurons, and this effect is saturated at a concentration of about 10 nM of oligomers. Both Aβ (1–40) and Aβ (1–42) oligomers have comparable effects. The rise in intracellular calcium is followed by an increase in the rate of ROS production by NADPH oxidase in both neurons and astrocytes. The increase in ROS production then triggers caspase-3 activation resulting in the inhibition of long-term potentiation. Our quantitative approach also reveals that only a small fraction of the oligomers are damaging and that an individual rare oligomer binding to an astrocyte can initiate the aforementioned cascade of responses, making it unlikely to be due to any specific interaction. Preincubating the Aβ oligomers with an extracellular chaperone, clusterin, sequesters the oligomers in long-lived complexes and inhibits all of the physiological damage, even at a ratio of 100:1, total Aβ to clusterin. To explain how Aβ oligomers are so damaging but that it takes decades to develop Alzheimer’s disease, we suggest a model for disease progression where small amounts of neuronal damage from individual unsequestered oligomers can accumulate over time leading to widespread tissue-level dysfunction. PMID:24717093

  1. Subtype Identification in Acutely Dissociated Rat Nodose Ganglion Neurons Based on Morphologic Parameters

    PubMed Central

    Lu, Xiao-Long; Xu, Wen-Xiao; Yan, Zhen-Yu; Qian, Zhao; Xu, Bing; Liu, Yang; Han, Li-Min; Gao, Rui-Chen; Li, Jun-Nan; Yuan, Mei; Zhao, Chong-Bao; Qiao, Guo-fen; Li, Bai-Yan

    2013-01-01

    Nodose ganglia are composed of A-, Ah- and C-type neurons. Despite their important roles in regulating visceral afferent function, including cardiovascular, pulmonary, and gastrointestinal homeostasis, information about subtype-specific expression, molecular identity, and function of individual ion transporting proteins is scarce. Although experiments utilizing the sliced ganglion preparation have provided valuable insights into the electrophysiological properties of nodose ganglion neuron subtypes, detailed characterization of their electrical phenotypes will require measurements in isolated cells. One major unresolved problem, however, is the difficulty to unambiguously identify the subtype of isolated nodose ganglion neurons without current-clamp recording, because the magnitude of conduction velocity in the corresponding afferent fiber, a reliable marker to discriminate subtypes in situ, can no longer be determined. Here, we present data supporting the notion that application of an algorithm regarding to microscopic structural characteristics, such as neuron shape evaluated by the ratio between shortest and longest axis, neuron surface characteristics, like membrane roughness, and axon attachment, enables specific and sensitive subtype identification of acutely dissociated rat nodose ganglion neurons, by which the accuracy of identification is further validated by electrophysiological markers and overall positive predictive rates is 89.26% (90.04%, 76.47%, and 98.21% for A-, Ah, and C-type, respectively). This approach should aid in gaining insight into the molecular correlates underlying phenotypic heterogeneity of nodose ganglia. Additionally, several critical points that help for neuron identification and afferent conduction calibration are also discussed. PMID:23904796

  2. Manganese Superoxide Dismutase Protects Mouse Cortical Neurons From Chronic Intermittent Hypoxia-Mediated Oxidative Damage

    PubMed Central

    Shan, Xiaoyang; Chi, Liying; Ke, Yan; Luo, Chun; Qian, Steven; Gozal, David; Liu, Rugao

    2007-01-01

    Obstructive Sleep Apnea (OSA) syndrome has been recognized as a highly prevalent public health problem and is associated with major neurobehavioral morbidity. Chronic intermittent hypoxia (CIH), a major pathological component of OSA, increases oxidative damage to the brain cortex and decreases neurocognitive function in rodent models resembling human OSA. We employed in vitro and in vivo approaches to identify the specific phases and subcellular compartments in which enhanced reactive oxygen species (ROS) are generated during CIH. In addition, we utilized the cell culture and animal models to analyze the consequences of enhanced production of ROS on cortical neuronal cell damage and neurocognitive dysfunction. In a primary cortical neuron culture system, we demonstrated that the transition phase from hypoxia to normoxia (NOX) during CIH generates more ROS than the transition phase from NOX to hypoxia or hypoxia alone, all of which generate more ROS than NOX. Using selective inhibitors of the major pathways underlying ROS generation in the cell membrane, cytosol, and mitochondria, we showed that the mitochondria are the predominant source of enhanced ROS generation during CIH in mouse cortical neuronal cells. Furthermore, in both cell culture and transgenic mice, we demonstrated that overexpression of MnSOD decreased CIH-mediated cortical neuronal apoptosis, and reduced spatial learning deficits measured with the Morris water maze assay. Together, the data from the in vitro and in vivo experiments indicate that CIH-mediated mitochondrial oxidative stress may play a major role in the neuronal cell loss and neurocognitive dysfunction in OSA. Thus, therapeutic strategies aiming at reducing ROS generation from mitochondria may improve the neurobehavioral morbidity in OSA. PMID:17719231

  3. Elevated metals compromise repair of oxidative DNA damage via the base excision repair pathway: implications of pathologic iron overload in the brain on integrity of neuronal DNA.

    PubMed

    Li, Hui; Swiercz, Rafal; Englander, Ella W

    2009-09-01

    Tissue-specific iron content is tightly regulated to simultaneously satisfy specialized metabolic needs and avoid cytotoxicity. In the brain, disruption of iron homeostasis may occur in acute as well as progressive injuries associated with neuronal dysfunction and death. We hypothesized that adverse effects of disrupted metal homeostasis on brain function may involve impairment of DNA repair processes. Because in the brain, the base excision repair (BER) pathway is central for handling oxidatively damaged DNA, we investigated effects of elevated iron and zinc on key BER enzymes. In vitro DNA repair assays revealed inhibitory effects of metals on BER activities, including the incision of abasic sites, 5'-flap cleavage, gap filling DNA synthesis and ligation. Using the comet assay, we showed that while metals at concentrations which inhibit BER activities in in vitro assays, did not induce direct genomic damage in cultured primary neurons, they significantly delayed repair of genomic DNA damage induced by sublethal exposure to H(2)O(2). Thus, in the brain even a mild transient metal overload, may adversely affect the DNA repair capacity and thereby compromise genomic integrity and initiate long-term deleterious sequelae including neuronal dysfunction and death. PMID:19619136

  4. Acute lipopolysaccharide exposure facilitates epileptiform activity via enhanced excitatory synaptic transmission and neuronal excitability in vitro

    PubMed Central

    Gao, Fei; Liu, Zhiqiang; Ren, Wei; Jiang, Wen

    2014-01-01

    Growing evidence indicates brain inflammation has been involved in the genesis of seizures. However, the direct effect of acute inflammation on neuronal circuits is not well known. Lipopolysaccharide (LPS) has been used extensively to stimulate brain inflammatory responses both in vivo and in vitro. Here, we observed the contribution of inflammation induced by 10 μg/mL LPS to the excitability of neuronal circuits in acute hippocampal slices. When slices were incubated with LPS for 30 minutes, significant increased concentration of tumor necrosis factor α and interleukin 1β were detected by enzyme-linked immunosorbent assay. In electrophysiological recordings, we found that frequency of epileptiform discharges and spikes per burst increased 30 minutes after LPS application. LPS enhanced evoked excitatory postsynaptic currents but did not modify evoked inhibitory postsynaptic currents. In addition, exposure to LPS enhanced the excitability of CA1 pyramidal neurons, as demonstrated by a decrease in rheobase and an increase in action potential frequency elicited by depolarizing current injection. Our observations suggest that acute inflammation induced by LPS facilitates epileptiform activity in vitro and that enhancement of excitatory synaptic transmission and neuronal excitability may contribute to this facilitation. These results may provide new clues for treating seizures associated with brain inflammatory disease. PMID:25170268

  5. Segregation of acute leptin and insulin effects in distinct populations of arcuate POMC neurons

    PubMed Central

    Williams, Kevin W.; Margatho, Lisandra O.; Lee, Charlotte E.; Choi, Michelle; Lee, Syann; Scott, Michael M.; Elias, Carol F.; Elmquist, Joel K.

    2010-01-01

    Acute leptin administration results in a depolarization and concomitant increase in the firing rate of a subpopulation of arcuate POMC cells. This rapid activation of POMC cells has been implicated as a cellular correlate of leptin effects on energy balance. In contrast to leptin, insulin inhibits the activity of some POMC neurons. Several studies have described a “cross-talk” between leptin and insulin within the mediobasal hypothalamus via the intracellular enzyme, phosphoinositol-3-kinase (PI3K). Interestingly, both insulin and leptin regulate POMC cellular activity by activation of PI3K, however it is unclear if leptin and insulin effects are observed in similar or distinct populations of POMC cells. We therefore used dual label immunohistochemistry/in situ hybridization and whole-cell patch-clamp electrophysiology to map insulin and leptin responsive arcuate POMC neurons. Leptin-induced Fos activity within arcuate POMC neurons was localized separate from POMC neurons which express insulin receptor. Moreover, acute responses to leptin and insulin were largely segregated in distinct sub-populations of POMC cells. Collectively, these data suggest that cross-talk between leptin and insulin occurs within a network of cells rather than within individual POMC neurons. PMID:20164331

  6. Acute intermittent optogenetic stimulation of nucleus tractus solitarius neurons induces sympathetic long-term facilitation

    PubMed Central

    Yamamoto, Kenta; Lalley, Peter

    2014-01-01

    Acute intermittent hypoxia (AIH) induces sympathetic and phrenic long-term facilitation (LTF), defined as a sustained increase in nerve discharge. We investigated the effects of AIH and acute intermittent optogenetic (AIO) stimulation of neurons labeled with AAV-CaMKIIa, hChR2(H134R), and mCherry in the nucleus of the solitary tract (NTS) of anesthetized, vagotomized, and mechanically ventilated rats. We measured renal sympathetic nerve activity (RSNA), phrenic nerve activity (PNA), power spectral density, and coherence, and we made cross-correlation measurements to determine how AIO stimulation and AIH affected synchronization between PNA and RSNA. Sixty minutes after AIH produced by ventilation with 10% oxygen in balanced nitrogen, RSNA and PNA amplitude increased by 80% and by 130%, respectively (P < 0.01). Sixty minutes after AIO stimulation, RSNA and PNA amplitude increased by 60% and 100%, respectively, (P < 0.01). These results suggest that acute intermittent stimulation of NTS neurons can induce renal sympathetic and phrenic LTF in the absence of hypoxia or chemoreceptor afferent activation. We also found that while acute intermittent optogenetic and hypoxic stimulations increased respiration-related RSNA modulation (P < 0.01), they did not increase synchronization between central respiratory drive and RSNA. We conclude that mechanisms that induce LTF originate within the caudal NTS and extend to other interconnecting neuronal elements of the central nervous cardiorespiratory network. PMID:25519734

  7. Gc-protein-derived macrophage activating factor counteracts the neuronal damage induced by oxaliplatin.

    PubMed

    Morucci, Gabriele; Branca, Jacopo J V; Gulisano, Massimo; Ruggiero, Marco; Paternostro, Ferdinando; Pacini, Alessandra; Di Cesare Mannelli, Lorenzo; Pacini, Stefania

    2015-02-01

    Oxaliplatin-based regimens are effective in metastasized advanced cancers. However, a major limitation to their widespread use is represented by neurotoxicity that leads to peripheral neuropathy. In this study we evaluated the roles of a proven immunotherapeutic agent [Gc-protein-derived macrophage activating factor (GcMAF)] in preventing or decreasing oxaliplatin-induced neuronal damage and in modulating microglia activation following oxaliplatin-induced damage. The effects of oxaliplatin and of a commercially available formula of GcMAF [oleic acid-GcMAF (OA-GcMAF)] were studied in human neurons (SH-SY5Y cells) and in human microglial cells (C13NJ). Cell density, morphology and viability, as well as production of cAMP and expression of vascular endothelial growth factor (VEGF), markers of neuron regeneration [neuromodulin or growth associated protein-43 (Gap-43)] and markers of microglia activation [ionized calcium binding adaptor molecule 1 (Iba1) and B7-2], were determined. OA-GcMAF reverted the damage inflicted by oxaliplatin on human neurons and preserved their viability. The neuroprotective effect was accompanied by increased intracellular cAMP production, as well as by increased expression of VEGF and neuromodulin. OA-GcMAF did not revert the effects of oxaliplatin on microglial cell viability. However, it increased microglial activation following oxaliplatin-induced damage, resulting in an increased expression of the markers Iba1 and B7-2 without any concomitant increase in cell number. When neurons and microglial cells were co-cultured, the presence of OA-GcMAF significantly counteracted the toxic effects of oxaliplatin. Our results demonstrate that OA-GcMAF, already used in the immunotherapy of advanced cancers, may significantly contribute to neutralizing the neurotoxicity induced by oxaliplatin, at the same time possibly concurring to an integrated anticancer effect. The association between these two powerful anticancer molecules would probably produce

  8. Neuronal Interleukin-4 as a Modulator of Microglial Pathways and Ischemic Brain Damage

    PubMed Central

    Zhao, Xiurong; Wang, Huan; Sun, Guanghua; Zhang, Jie; Edwards, Nancy J.

    2015-01-01

    After ischemic stroke, various damage-associated molecules are released from the ischemic core and diffuse to the ischemic penumbra, activating microglia and promoting proinflammatory responses that may cause damage to the local tissue. Here we demonstrate using in vivo and in vitro models that, during sublethal ischemia, local neurons rapidly produce interleukin-4 (IL-4), a cytokine with potent anti-inflammatory properties. One such anti-inflammatory property includes its ability to polarize macrophages away from a proinflammatory M1 phenotype to a “healing” M2 phenotype. Using an IL-4 reporter mouse, we demonstrated that IL-4 expression was induced preferentially in neurons in the ischemic penumbra but not in the ischemic core or in brain regions that were spared from ischemia. When added to cultured microglia, IL-4 was able to induce expression of genes typifying the M2 phenotype and peroxisome proliferator activated receptor γ (PPARγ) activation. IL-4 also enhanced expression of the IL-4 receptor on microglia, facilitating a “feedforward” increase in (1) their expression of trophic factors and (2) PPARγ-dependent phagocytosis of apoptotic neurons. Parenteral administration of IL-4 resulted in augmented brain expression of M2- and PPARγ-related genes. Furthermore, IL-4 and PPARγ agonist administration improved functional recovery in a clinically relevant mouse stroke model, even if administered 24 h after the onset of ischemia. We propose that IL-4 is secreted by ischemic neurons as an endogenous defense mechanism, playing a vital role in the regulation of brain cleanup and repair after stroke. Modulation of IL-4 and its associated pathways could represent a potential target for ischemic stroke treatment. SIGNIFICANCE STATEMENT Depending on the activation signal, microglia/macrophages (MΦ) can behave as “healing” (M2) or “harmful” (M1). In response to ischemia, damaged/necrotic brain cells discharge factors that polarize MΦ to a M1-like

  9. NAAG reduces NMDA receptor current in CA1 hippocampal pyramidal neurons of acute slices and dissociated neurons.

    PubMed

    Bergeron, Richard; Coyle, Joseph T; Tsai, Guochan; Greene, Robert W

    2005-01-01

    N-acetylaspartylglutamate (NAAG) is an abundant neuropeptide in the nervous system, yet its functions are not well understood. Pyramidal neurons of the CA1 sector of acutely prepared hippocampal slices were recorded using the whole-cell patch-clamp technique. At low concentrations (20 microM), NAAG reduced isolated N-methyl-D-aspartate receptor (NMDAR)-mediated synaptic currents or NMDA-induced currents. The NAAG-induced change in the NMDA concentration/response curve suggested that the antagonism was not competitive. However, the NAAG-induced change in the concentration/response curve for the NMDAR co-agonist, glycine, indicated that glycine can overcome the NAAG antagonism. The antagonism of the NMDAR induced by NAAG was still observed in the presence of LY-341495, a potent and selective mGluR3 antagonist. Moreover, in dissociated pyramidal neurons of the CA1 region, NAAG also reduced the NMDA current and this effect was reversed by glycine. These results suggest that NAAG reduces the NMDA currents in hippocampal CA1 pyramidal neurons. PMID:15354184

  10. Repetitive acute intermittent hypoxia increases growth/neurotrophic factor expression in non-respiratory motor neurons.

    PubMed

    Satriotomo, I; Nichols, N L; Dale, E A; Emery, A T; Dahlberg, J M; Mitchell, G S

    2016-05-13

    Repetitive acute intermittent hypoxia (rAIH) increases growth/trophic factor expression in respiratory motor neurons, thereby eliciting spinal respiratory motor plasticity and/or neuroprotection. Here we demonstrate that rAIH effects are not unique to respiratory motor neurons, but are also expressed in non-respiratory, spinal alpha motor neurons and upper motor neurons of the motor cortex. In specific, we used immunohistochemistry and immunofluorescence to assess growth/trophic factor protein expression in spinal sections from rats exposed to AIH three times per week for 10weeks (3×wAIH). 3×wAIH increased brain-derived neurotrophic factor (BDNF), its high-affinity receptor, tropomyosin receptor kinase B (TrkB), and phosphorylated TrkB (pTrkB) immunoreactivity in putative alpha motor neurons of spinal cervical 7 (C7) and lumbar 3 (L3) segments, as well as in upper motor neurons of the primary motor cortex (M1). 3×wAIH also increased immunoreactivity of vascular endothelial growth factor A (VEGFA), the high-affinity VEGFA receptor (VEGFR-2) and an important VEGF gene regulator, hypoxia-inducible factor-1α (HIF-1α). Thus, rAIH effects on growth/trophic factors are characteristic of non-respiratory as well as respiratory motor neurons. rAIH may be a useful tool in the treatment of disorders causing paralysis, such as spinal injury and motor neuron disease, as a pretreatment to enhance motor neuron survival during disease, or as preconditioning for cell-transplant therapies. PMID:26944605

  11. Nucleus accumbens neuronal activity in freely behaving rats is modulated following acute and chronic methylphenidate administration.

    PubMed

    Chong, Samuel L; Claussen, Catherine M; Dafny, Nachum

    2012-03-10

    Methylphenidate (MPD) is a psychostimulant that enhances dopaminergic neurotransmission in the central nervous system by using mechanisms similar to cocaine and amphetamine. The mode of action of brain circuitry responsible for an animal's neuronal response to MPD is not fully understood. The nucleus accumbens (NAc) has been implicated in regulating the rewarding effects of psychostimulants. The present study used permanently implanted microelectrodes to investigate the acute and chronic effects of MPD on the firing rates of NAc neuronal units in freely behaving rats. On experimental day 1 (ED1), following a saline injection (control), a 30 min baseline neuronal recording was obtained immediately followed by a 2.5 mg/kg i.p. MPD injection and subsequent 60 min neuronal recording. Daily 2.5 mg/kg MPD injections were given on ED2 through ED6 followed by 3 washout days (ED7 to ED9). On ED10, neuronal recordings were resumed from the same animal after a saline and MPD (rechallenge) injection exactly as obtained on ED1. Sixty-seven NAc neuronal units exhibited similar wave shape, form and amplitude on ED1 and ED10 and their firing rates were used for analysis. MPD administration on ED1 elicited firing rate increases and decreases in 54% of NAc units when compared to their baselines. Six consecutive MPD administrations altered the neuronal baseline firing rates of 85% of NAc units. MPD rechallenge on ED10 elicited significant changes in 63% of NAc units. These alterations in firing rates are hypothesized to be through mechanisms that include D1 and D2-like DA receptor induced cellular adaptation and homeostatic adaptations/deregulation caused by acute and chronic MPD administration. PMID:22248440

  12. Methamphetamine causes acute hyperthermia-dependent liver damage.

    PubMed

    Halpin, Laura E; Gunning, William T; Yamamoto, Bryan K

    2013-10-01

    Methamphetamine-induced neurotoxicity has been correlated with damage to the liver but this damage has not been extensively characterized. Moreover, the mechanism by which the drug contributes to liver damage is unknown. This study characterizes the hepatocellular toxicity of methamphetamine and examines if hyperthermia contributes to this liver damage. Livers from methamphetamine-treated rats were examined using electron microscopy and hematoxylin and eosin staining. Methamphetamine increased glycogen stores, mitochondrial aggregation, microvesicular lipid, and hydropic change. These changes were diffuse throughout the hepatic lobule, as evidenced by a lack of hematoxylin and eosin staining. To confirm if these changes were indicative of damage, serum aspartate and alanine aminotransferase were measured. The functional significance of methamphetamine-induced liver damage was also examined by measuring plasma ammonia. To examine the contribution of hyperthermia to this damage, methamphetamine-treated rats were cooled during and after drug treatment by cooling their external environment. Serum aspartate and alanine aminotransferase, as well as plasma ammonia were increased concurrently with these morphologic changes and were prevented when methamphetamine-induced hyperthermia was blocked. These findings support that methamphetamine produces changes in hepatocellular morphology and damage persisting for at least 24 h after drug exposure. At this same time point, methamphetamine treatment significantly increases plasma ammonia concentrations, consistent with impaired ammonia metabolism and functional liver damage. Methamphetamine-induced hyperthermia contributes significantly to the persistent liver damage and increases in peripheral ammonia produced by the drug. PMID:25505562

  13. Methamphetamine causes acute hyperthermia-dependent liver damage

    PubMed Central

    Halpin, Laura E; Gunning, William T; Yamamoto, Bryan K

    2013-01-01

    Methamphetamine-induced neurotoxicity has been correlated with damage to the liver but this damage has not been extensively characterized. Moreover, the mechanism by which the drug contributes to liver damage is unknown. This study characterizes the hepatocellular toxicity of methamphetamine and examines if hyperthermia contributes to this liver damage. Livers from methamphetamine-treated rats were examined using electron microscopy and hematoxylin and eosin staining. Methamphetamine increased glycogen stores, mitochondrial aggregation, microvesicular lipid, and hydropic change. These changes were diffuse throughout the hepatic lobule, as evidenced by a lack of hematoxylin and eosin staining. To confirm if these changes were indicative of damage, serum aspartate and alanine aminotransferase were measured. The functional significance of methamphetamine-induced liver damage was also examined by measuring plasma ammonia. To examine the contribution of hyperthermia to this damage, methamphetamine-treated rats were cooled during and after drug treatment by cooling their external environment. Serum aspartate and alanine aminotransferase, as well as plasma ammonia were increased concurrently with these morphologic changes and were prevented when methamphetamine-induced hyperthermia was blocked. These findings support that methamphetamine produces changes in hepatocellular morphology and damage persisting for at least 24 h after drug exposure. At this same time point, methamphetamine treatment significantly increases plasma ammonia concentrations, consistent with impaired ammonia metabolism and functional liver damage. Methamphetamine-induced hyperthermia contributes significantly to the persistent liver damage and increases in peripheral ammonia produced by the drug. PMID:25505562

  14. NGF rescues DRG neurons in vitro from oxidative damage produced by hemodialyzers.

    PubMed

    Podratz, Jewel L; Windebank, Anthony J

    2005-06-01

    Using dorsal root ganglion neurons (DRG), in vitro, we studied the effects of nerve growth factor (NGF) on a toxin extracted from ethylene oxide (EO) sterilized hemodialyzers. Tissue culture medium passed through dialyzers produced beading of DRG axons that was inhibited by increasing the concentration of NGF from 3.5 to 10 ng/ml. The antioxidant enzymes, catalase and glutathione peroxidase (GPx), prevented neurite beading while superoxide dismutase (SOD) alone did not. 3-amino-1,2,4-triazole (Az), an inhibitor of catalase blocked the protective effects of catalase and NGF. 1,3 bis[chloromethyl]-1-nitrosourea (BCNU) inhibits glutathione reductase, and reduces intracellular glutathione levels; it blocked the protective effects of NGF. Dialyzer treated medium was found to have increased peroxide content. In parallel experiments, NGF protected DRG neurons from hydrogen peroxide (H(2)O(2)) toxicity that was inhibited by Az and BCNU. NGF was also shown to upregulate glutathione in DRG neurons. We propose that EO gas used in the sterilization of hemodialyzers is responsible for the neurotoxicity and is most likely due to oxidative damage in DRG neurons. NGF protects DRG from this toxin by upregulating antioxidants such as catalase, GPx and GSH. PMID:15935206

  15. Acute traumatic anterior glenohumeral dislocation complicated by axillary nerve damage: a case report

    PubMed Central

    Kazemi, Mohsen

    1998-01-01

    An elite soccer player presented with a classic acute anterior dislocation of the glenohumeral joint complicated by axillary nerve damage. The incidence, mechanism of injury, clinical presentation, conservative treatment and rehabilitation of the anterior glenohumeral joint dislocation and associated axillary nerve damage are discussed in this paper. ImagesFigure 3

  16. The Response to Oxidative DNA Damage in Neurons: Mechanisms and Disease

    PubMed Central

    Narciso, Laura; Parlanti, Eleonora; Racaniello, Mauro; Simonelli, Valeria; Cardinale, Alessio; Merlo, Daniela; Dogliotti, Eugenia

    2016-01-01

    There is a growing body of evidence indicating that the mechanisms that control genome stability are of key importance in the development and function of the nervous system. The major threat for neurons is oxidative DNA damage, which is repaired by the base excision repair (BER) pathway. Functional mutations of enzymes that are involved in the processing of single-strand breaks (SSB) that are generated during BER have been causally associated with syndromes that present important neurological alterations and cognitive decline. In this review, the plasticity of BER during neurogenesis and the importance of an efficient BER for correct brain function will be specifically addressed paying particular attention to the brain region and neuron-selectivity in SSB repair-associated neurological syndromes and age-related neurodegenerative diseases. PMID:26942017

  17. Acute and long term respiratory damage following inhalation of ammonia.

    PubMed Central

    Leduc, D; Gris, P; Lheureux, P; Gevenois, P A; De Vuyst, P; Yernault, J C

    1992-01-01

    A lifelong non-smoker who was the victim of a massive accidental exposure to anhydrous ammonia gas was followed up for 10 years. In the acute phase the patient presented with severe tracheobronchitis and respiratory failure, caused by very severe burns of the respiratory mucosa. After some improvement he was left with severe and fixed airways obstruction. Isotope studies of mucociliary clearance, computed tomography, and bronchography showed mild bronchiectasis. It is concluded that acute exposure to high concentrations of ammonia may lead to acute respiratory injury but also to long term impairment of respiratory function. Images PMID:1440475

  18. Protective action of erythropoietin on neuronal damage induced by activated microglia.

    PubMed

    Wenker, Shirley D; Chamorro, María E; Vittori, Daniela C; Nesse, Alcira B

    2013-04-01

    Inflammation is a physiological defense response, but may also represent a potential pathological process in neurological diseases. In this regard, microglia have a crucial role in either progression or amelioration of degenerative neuronal damage. Because of the role of hypoxia in pro-inflammatory mechanisms in the nervous system, and the potential anti-inflammatory protective effect of erythropoietin (Epo), we focused our investigation on the role of this factor on activation of microglia and neuroprotection. Activation of microglial cells (EOC-2) was achieved by chemical hypoxia induced by cobalt chloride (CoCl2 ) and characterized by increased levels of nitrite, tumor necrosis factor-α and reactive oxygen species production, as well as up-regulation of inducible nitric oxide synthase expression. Under these conditions, cell proliferation data and proliferating cell nuclear antigen (PCNA) staining demonstrated a mitogenic effect of chemical hypoxia. Even though pre-treatment with Epo did not prevent nitrite production, inducible nitric oxide synthase protein expression or tumor necrosis factor-α secretion, it prevented the oxidative stress induced by CoCl2 as well as cell proliferation. Neuronal cells (SH-SY5Y) cultured in the presence of conditioned medium from activated EOC-2 cells or macrophages (RAW 264.7) developed significant apoptosis, an effect that was abolished by Epo via Epo/Epo receptor activation. The results show that even though Epo did not exert a direct anti-inflammatory effect on microglia activation, it did increase the resistance of neurons to subsequent damage from pro-inflammatory agents. In addition to its anti-apoptotic ability, the Epo antioxidant effect may have an indirect influence on neuronal survival by modulation of the pro-inflammatory environment. PMID:23384249

  19. Interleukin-1 receptor antagonist inhibits neuronal damage caused by fluid percussion injury in the rat.

    PubMed

    Toulmond, S; Rothwell, N J

    1995-02-13

    Increased expression of the cytokine interleukin-1 (IL-1) has been observed in rodent and human brain after injury, and IL-1 has been implicated in ischaemic and excitotoxic brain damage in the rat. These data suggest that neurodegeneration caused by brain injury may be mediated by local IL-1 production and action. This hypothesis was tested by studying the effects of central injection of recombinant human interleukin-1 receptor antagonist (rhIL-1ra) on brain damage (assessed histologically, H and E stain) induced by fluid percussion trauma in the rat. Injection of rhIL-1ra (10 micrograms, i.c.v.) 15 min and 2, 4, 6, 8, 24 and 48 h after injury significantly reduced, by 44%, the extent of damage measured 3 days later. Similar protection was observed in animals killed 7 days after injury. Delayed administration of rhIL-1ra (4, 6, 8, 24 and 48 h) after injury also significantly reduced (by 28%) neuronal damage. These data indicate that endogenous IL-1 mediates damage caused by traumatic brain injury and that rhIL-1ra offers significant protection even when treatment is delayed. PMID:7743213

  20. Inhalation anesthetic-induced neuronal damage in the developing rhesus monkey.

    PubMed

    Zou, Xiaoju; Liu, Fang; Zhang, Xuan; Patterson, Tucker A; Callicott, Ralph; Liu, Shuliang; Hanig, Joseph P; Paule, Merle G; Slikker, William; Wang, Cheng

    2011-01-01

    The combination of nitrous oxide gas (N(2)O) and isoflurane (ISO) vapor is commonly used in pediatric surgical procedures for human infants and children to produce unconsciousness and analgesia. Because of obvious limitations it is difficult to thoroughly explore the effects of pediatric anesthetic agents on neurons in human infants or children. Due to the complexity of the primate brain, the monkey is often the animal model of choice for developmental neurotoxicology experiments, and it is in the rhesus monkey that the phenomenon of interest (anesthetic-induced neuronal cell death in the brain) has been previously reported. Recent reports indicate that exposure of the developing brain to general anesthetics that block N-methyl-D-aspartate (NMDA)-type glutamate receptors or potentiate gamma-aminobutyric acid (GABA) receptors can trigger widespread apoptotic cell death in rodents. The present study was performed to determine whether prolonged exposure of developing nonhuman primates to a clinically relevant combination of nitrous oxide and isoflurane produces neuronal damage. Postnatal day (PND) 5-6 rhesus monkeys were exposed to N(2)O (70%) or ISO (1.0%) alone, or N(2)O plus ISO for 8 h. Inhalation of the combination of 70% N(2)O+1% ISO produces a surgical plane of anesthesia. Six hours after completion of anesthetic administration the monkeys were examined for neurotoxic effects. No significant neurotoxic effects were observed for the monkeys exposed to N(2)O or ISO alone. However, neuronal damage was apparent when N(2)O was combined with ISO as indicated by increased numbers of caspase-3-, Silver staining- and Fluoro-Jade C-positive cells in the frontal cortex, temporal gyrus and hippocampus. Electron micrographs indicated typical swelling of the cytoplasm and nuclear condensation in the frontal cortex. These data suggest that prolonged exposure to inhaled anesthetics (a combination of N(2)O and ISO) in the developing rhesus monkey results in neuronal damage, and

  1. Calcium Imaging of AM Dyes Following Prolonged Incubation in Acute Neuronal Tissue

    PubMed Central

    Morley, John W.; Tapson, Jonathan; Breen, Paul P.; van Schaik, André

    2016-01-01

    Calcium-imaging is a sensitive method for monitoring calcium dynamics during neuronal activity. As intracellular calcium concentration is correlated to physiological and pathophysiological activity of neurons, calcium imaging with fluorescent indicators is one of the most commonly used techniques in neuroscience today. Current methodologies for loading calcium dyes into the tissue require prolonged incubation time (45–150 min), in addition to dissection and recovery time after the slicing procedure. This prolonged incubation curtails experimental time, as tissue is typically maintained for 6–8 hours after slicing. Using a recently introduced recovery chamber that extends the viability of acute brain slices to more than 24 hours, we tested the effectiveness of calcium AM staining following long incubation periods post cell loading and its impact on the functional properties of calcium signals in acute brain slices and wholemount retinae. We show that calcium dyes remain within cells and are fully functional >24 hours after loading. Moreover, the calcium dynamics recorded >24 hrs were similar to the calcium signals recorded in fresh tissue that was incubated for <4 hrs. These results indicate that long exposure of calcium AM dyes to the intracellular cytoplasm did not alter the intracellular calcium concentration, the functional range of the dye or viability of the neurons. This data extends our previous work showing that a custom recovery chamber can extend the viability of neuronal tissue, and reliable data for both electrophysiology and imaging can be obtained >24hrs after dissection. These methods will not only extend experimental time for those using acute neuronal tissue, but also may reduce the number of animals required to complete experimental goals. PMID:27183102

  2. Konzo: a distinct disease entity with selective upper motor neuron damage.

    PubMed Central

    Tylleskär, T; Howlett, W P; Rwiza, H T; Aquilonius, S M; Stålberg, E; Lindén, B; Mandahl, A; Larsen, H C; Brubaker, G R; Rosling, H

    1993-01-01

    Two Tanzanian patients with konzo were severely disabled by a non-progressive spastic paraparesis, since the sudden onset during an epidemic six years earlier. At the time of onset they had a high dietary intake of cyanide from exclusive consumption of insufficiently processed bitter cassava roots. MRI of brain and spinal cord were normal but motor evoked potentials on magnetic brain stimulation were absent, even in the only slightly affected upper limbs. Other neurophysiological investigations were largely normal but the more affected patient had central visual field defects. Konzo is a distinct disease entity with selective type upper motor neuron damage. Images PMID:8509777

  3. Brain-derived neurotrophic factor acutely inhibits AMPA-mediated currents in developing sensory relay neurons.

    PubMed

    Balkowiec, A; Kunze, D L; Katz, D M

    2000-03-01

    Brain-derived neurotrophic factor (BDNF) is expressed by many primary sensory neurons that no longer require neurotrophins for survival, indicating that BDNF may be used as a signaling molecule by the afferents themselves. Because many primary afferents also express glutamate, we investigated the possibility that BDNF modulates glutamatergic AMPA responses of newborn second-order sensory relay neurons. Perforated-patch, voltage-clamp recordings were made from dissociated neurons of the brainstem nucleus tractus solitarius (nTS), a region that receives massive primary afferent input from BDNF-containing neurons in the nodose and petrosal cranial sensory ganglia. Electrophysiological analysis was combined in some experiments with anterograde labeling of primary afferent terminals to specifically analyze responses of identified second-order neurons. Our data demonstrate that BDNF strongly inhibits AMPA-mediated currents in a large subset of nTS cells. Specifically, AMPA responses were either completely abolished or markedly inhibited by BDNF in 73% of postnatal day (P0) cells and in 82% of identified P5 second-order sensory relay neurons. This effect of BDNF is mimicked by NT-4, but not NGF, and blocked by the Trk tyrosine kinase inhibitor K252a, consistent with a requirement for TrkB receptor activation. Moreover, analysis of TrkB expression in culture revealed a close correlation between the percentage of nTS neurons in which BDNF inhibits AMPA currents and the percentage of neurons that exhibit TrkB immunoreactivity. These data document a previously undefined mechanism of acute modulation of AMPA responses by BDNF and indicate that BDNF may regulate glutamatergic transmission at primary afferent synapses. PMID:10684891

  4. Combined Exposure to Simulated Microgravity and Acute or Chronic Radiation Reduces Neuronal Network Integrity and Survival

    PubMed Central

    Quintens, Roel; Samari, Nada; de Saint-Georges, Louis; van Oostveldt, Patrick; Baatout, Sarah; Benotmane, Mohammed Abderrafi

    2016-01-01

    During orbital or interplanetary space flights, astronauts are exposed to cosmic radiations and microgravity. However, most earth-based studies on the potential health risks of space conditions have investigated the effects of these two conditions separately. This study aimed at assessing the combined effect of radiation exposure and microgravity on neuronal morphology and survival in vitro. In particular, we investigated the effects of simulated microgravity after acute (X-rays) or during chronic (Californium-252) exposure to ionizing radiation using mouse mature neuron cultures. Acute exposure to low (0.1 Gy) doses of X-rays caused a delay in neurite outgrowth and a reduction in soma size, while only the high dose impaired neuronal survival. Of interest, the strongest effect on neuronal morphology and survival was evident in cells exposed to microgravity and in particular in cells exposed to both microgravity and radiation. Removal of neurons from simulated microgravity for a period of 24 h was not sufficient to recover neurite length, whereas the soma size showed a clear re-adaptation to normal ground conditions. Genome-wide gene expression analysis confirmed a modulation of genes involved in neurite extension, cell survival and synaptic communication, suggesting that these changes might be responsible for the observed morphological effects. In general, the observed synergistic changes in neuronal network integrity and cell survival induced by simulated space conditions might help to better evaluate the astronaut's health risks and underline the importance of investigating the central nervous system and long-term cognition during and after a space flight. PMID:27203085

  5. Combined Exposure to Simulated Microgravity and Acute or Chronic Radiation Reduces Neuronal Network Integrity and Survival.

    PubMed

    Pani, Giuseppe; Verslegers, Mieke; Quintens, Roel; Samari, Nada; de Saint-Georges, Louis; van Oostveldt, Patrick; Baatout, Sarah; Benotmane, Mohammed Abderrafi

    2016-01-01

    During orbital or interplanetary space flights, astronauts are exposed to cosmic radiations and microgravity. However, most earth-based studies on the potential health risks of space conditions have investigated the effects of these two conditions separately. This study aimed at assessing the combined effect of radiation exposure and microgravity on neuronal morphology and survival in vitro. In particular, we investigated the effects of simulated microgravity after acute (X-rays) or during chronic (Californium-252) exposure to ionizing radiation using mouse mature neuron cultures. Acute exposure to low (0.1 Gy) doses of X-rays caused a delay in neurite outgrowth and a reduction in soma size, while only the high dose impaired neuronal survival. Of interest, the strongest effect on neuronal morphology and survival was evident in cells exposed to microgravity and in particular in cells exposed to both microgravity and radiation. Removal of neurons from simulated microgravity for a period of 24 h was not sufficient to recover neurite length, whereas the soma size showed a clear re-adaptation to normal ground conditions. Genome-wide gene expression analysis confirmed a modulation of genes involved in neurite extension, cell survival and synaptic communication, suggesting that these changes might be responsible for the observed morphological effects. In general, the observed synergistic changes in neuronal network integrity and cell survival induced by simulated space conditions might help to better evaluate the astronaut's health risks and underline the importance of investigating the central nervous system and long-term cognition during and after a space flight. PMID:27203085

  6. Neuron Growth on Carbon Nanotube Thread Bio-Scaffolds for Repair of Central Nervous System Damage

    NASA Astrophysics Data System (ADS)

    Mast, David; Pixley, Sarah; Schulz, Mark; Shanov, Vessilin

    2012-02-01

    Approximately 11,000 new spinal cord injuries occur each year. Repairing such central nervous system (CNS) damage has proven to be very difficult. We report on in vitro experiments using carbon nanotube (CNT) threads as a bio-scaffold for promoting CNS repair via directed neuron regrowth along the CNT material. Mouse brain neurospheres, containing neuronal stem cells, neurons and support glia, were observed to attach to and grow along laminin-coated CNT threads in vitro. However, due to their limited mobility, only neurospheres close to the threads attach. To increase cellular attachment to the threads, we exploit the fact that these cells can exhibit enhanced, directed migration along an externally applied electric field. Recent in vitro cell growth was carried out in chambers containing several parallel CNT threads with electrical connections extending out of the incubator so that a voltage applied across adjacent threads established an appropriate electric field. Electrochemical Impedance Spectroscopy, Cyclic Voltammetry and dc and ac IV measurements were used to monitor cell growth and attachment as a function of applied electric field and time. Cell migration and attachment were also investigated using time lapse photography in a separate growth chamber mounted on the stage of an optical microscope.

  7. Donepezil attenuates excitotoxic damage induced by membrane depolarization of cortical neurons exposed to veratridine.

    PubMed

    Akasofu, Shigeru; Sawada, Kohei; Kosasa, Takashi; Hihara, Hiroe; Ogura, Hiroo; Akaike, Akinori

    2008-07-01

    Long-lasting membrane depolarization in cerebral ischemia causes neurotoxicity via increases of intracellular sodium concentration ([Na+]i) and calcium concentration ([Ca2+]i). Donepezil has been shown to exert neuroprotective effects in an oxygen-glucose deprivation model. In the present study, we examined the effect of donepezil on depolarization-induced neuronal cell injury resulting from prolonged opening of Na+ channels with veratridine in rat primary-cultured cortical neurons. Veratridine (10 microM)-induced neuronal cell damage was completely prevented by 0.1 microM tetrodotoxin. Pretreatment with donepezil (0.1-10 microM) for 1 day significantly decreased cell death in a concentration-dependent manner, and a potent NMDA receptor antagonist, dizocilpine (MK801), showed a neuroprotective effect at the concentration of 10 microM. The neuroprotective effect of donepezil was not affected by nicotinic or muscarinic acetylcholine receptor antagonists. We further characterized the neuroprotective properties of donepezil by measuring the effect on [Na+]i and [Ca2+]i in cells stimulated with veratridine. At 0.1-10 microM, donepezil significantly and concentration-dependently reduced the veratridine-induced increase of [Ca2+]i, whereas MK801 had no effect. At 10 microM, donepezil significantly decreased the veratridine-induced increase of [Na+]i. We also measured the effect on veratridine-induced release of the excitatory amino acids, glutamate and glycine. While donepezil decreased the release of glutamate and glycine, MK801 did not. In conclusion, our results indicate that donepezil has neuroprotective activity against depolarization-induced toxicity in rat cortical neurons via inhibition of the rapid influx of sodium and calcium ions, and via decrease of glutamate and glycine release, and also that this depolarization-induced toxicity is mediated by glutamate receptor activation. PMID:18508044

  8. Cytarabine induced cerebellar neuronal damage in juvenile rat: correlating neurobehavioral performance with cellular and genetic alterations.

    PubMed

    Patel, Ronak S; Rachamalla, Mahesh; Chary, Namoju R; Shera, Firdos Y; Tikoo, Kulbhushan; Jena, Gopabandhu

    2012-03-11

    Cytosine arabinoside (Ara-C), a pyrimidine analogue induces cerebellar dysfunction and behavioral abnormalities. Although many in vitro experiments have been conducted in the past demonstrating the lethal potential of Ara-C to cerebellar neurons, there is a paucity of literature available regarding the effects of Ara-C on the cellular and genetic material of cerebellum and its subsequent influence on the neurobehavioral performance in vivo. Rats were treated with Ara-C at the dose levels 50, 100 and 200mg/kg/day for 5 and 14 days by intraperitoneal (i.p.) route. Endpoints of the evaluation included food and water intake, body and organ weight, behavioral parameters, histopathology, oxidative stress, DNA damage, apoptosis, expression of p53, caspase-3 and calbindin D-28K (calbindin) as well as histone acetylation and methylation. Ara-C treatment for 14 days significantly decreased the food and water intake, body weight gain and brain weight in rat as compared to the control. Alterations in various behavioral parameters were observed, indicating the impaired cerebellar function. Further, cellular abnormalities in the cerebellum such as Purkinje cell misalignment and granule cell cytotoxicity were observed. Positive correlation was observed between Ara-C induced disturbance in the motor performance and the Purkinje cell loss in rat cerebellum. Moreover, Ara-C treatment significantly increased the oxidative stress, DNA damage, TUNEL positive cells, p53 and caspase-3 positive cells in the rat cerebellum. Unlike short-term treatment, long-term Ara-C treatment significantly reduced calbindin expression in the cerebellum. Apart from this, 14 days Ara-C treatment led to significant alterations in the histone acetylation and methylation in the cerebellum, while in 5 days treatment no such alterations were observed. Present results indicated that Ara-C, by inducing oxidative stress mediated DNA damage, executes neuronal apoptosis which is accompanied by an increase in the p53

  9. E2F1 localizes predominantly to neuronal cytoplasm and fails to induce expression of its transcriptional targets in Human Immunodeficiency Virus-induced neuronal damage

    PubMed Central

    Wang, Ying; Shyam, Nikhil; Ting, Jenhao H.; Akay, Cagla; Lindl, Kathryn A.; Jordan-Sciutto, Kelly L.

    2010-01-01

    As human immunodeficiency virus (HIV) does not induce neuronal damage by direct infection, the mechanisms of neuronal damage or loss in HIV associated dementia (HAD) remain unclear. We have shown previously that immunoreactivity of transcription factor, E2F1, increases in neurons, localizing predominantly to the cytoplasm, in HIV-associated pathologies. Here we confirm that E2F1 localization is predominantly cytoplasmic in primary post-mitotic neurons in vitro and cortical neurons in vivo. To determine whether E2F1 contributes to neuronal death in HAD via transactivation of target promoters, we assessed the mRNA and protein levels of several classical E2F1 transcriptional targets implicated in cell cycle progression and apoptosis in an in vitro model of HIV-induced neurotoxicity and in cortical autopsy tissue from patients infected with HIV. By qPCR, we show that mRNA levels of E2F1 transcriptional targets implicated in cell cycle progression (E2F1, cyclin A, proliferating cell nuclear antigen (PCNA), and dyhydrofolate reductase (DHFR)) and apoptosis (caspases 3, 8, 9 and p19ARF) remain unchanged in an in vitro model of HIV-induced neurotoxicity. Further, we show that protein levels of p19ARF, Cyclin A, and PCNA are not altered in vitro or in the cortex of patients with HAD. We propose that the predominantly cytoplasmic localization of E2F1 in neurons may account for the lack of E2F1 target transactivation in neurons responding to HIV-induced neurotoxicity. PMID:20580656

  10. cAMP-Inhibits Cytoplasmic Phospholipase A2 and Protects Neurons against Amyloid-β-Induced Synapse Damage

    PubMed Central

    Bate, Clive; Williams, Alun

    2015-01-01

    A key event in Alzheimer’s disease (AD) is the production of amyloid-β (Aβ) peptides and the loss of synapses. In cultured neurons Aβ triggered synapse damage as measured by the loss of synaptic proteins. α-synuclein (αSN), aggregates of which accumulate in Parkinson’s disease, also caused synapse damage. Synapse damage was associated with activation of cytoplasmic phospholipase A2 (cPLA2), an enzyme that regulates synapse function and structure, and the production of prostaglandin (PG) E2. In synaptosomes PGE2 increased concentrations of cyclic adenosine monophosphate (cAMP) which suppressed the activation of cPLA2 demonstrating an inhibitory feedback system. Thus, Aβ/αSN-induced activated cPLA2 produces PGE2 which increases cAMP which in turn suppresses cPLA2 and, hence, its own production. Neurons pre-treated with pentoxifylline and caffeine (broad spectrum phosphodiesterase (PDE) inhibitors) or the PDE4 specific inhibitor rolipram significantly increased the Aβ/αSN-induced increase in cAMP and consequently protected neurons against synapse damage. The addition of cAMP analogues also inhibited cPLA2 and protected neurons against synapse damage. These results suggest that drugs that inhibit Aβ-induced activation of cPLA2 and cross the blood–brain barrier may reduce synapse damage in AD. PMID:26389963

  11. cAMP-Inhibits Cytoplasmic Phospholipase A₂ and Protects Neurons against Amyloid-β-Induced Synapse Damage.

    PubMed

    Bate, Clive; Williams, Alun

    2015-01-01

    A key event in Alzheimer's disease (AD) is the production of amyloid-β (Aβ) peptides and the loss of synapses. In cultured neurons Aβ triggered synapse damage as measured by the loss of synaptic proteins. α-synuclein (αSN), aggregates of which accumulate in Parkinson's disease, also caused synapse damage. Synapse damage was associated with activation of cytoplasmic phospholipase A₂ (cPLA₂), an enzyme that regulates synapse function and structure, and the production of prostaglandin (PG) E₂. In synaptosomes PGE₂ increased concentrations of cyclic adenosine monophosphate (cAMP) which suppressed the activation of cPLA₂ demonstrating an inhibitory feedback system. Thus, Aβ/αSN-induced activated cPLA₂ produces PGE₂ which increases cAMP which in turn suppresses cPLA₂ and, hence, its own production. Neurons pre-treated with pentoxifylline and caffeine (broad spectrum phosphodiesterase (PDE) inhibitors) or the PDE4 specific inhibitor rolipram significantly increased the Aβ/αSN-induced increase in cAMP and consequently protected neurons against synapse damage. The addition of cAMP analogues also inhibited cPLA₂ and protected neurons against synapse damage. These results suggest that drugs that inhibit Aβ-induced activation of cPLA₂ and cross the blood-brain barrier may reduce synapse damage in AD. PMID:26389963

  12. Apoptosis of hippocampal pyramidal neurons is virus independent in a mouse model of acute neurovirulent picornavirus infection.

    PubMed

    Buenz, Eric J; Sauer, Brian M; Lafrance-Corey, Reghann G; Deb, Chandra; Denic, Aleksandar; German, Christopher L; Howe, Charles L

    2009-08-01

    Many viruses, including picornaviruses, have the potential to infect the central nervous system (CNS) and stimulate a neuroinflammatory immune response, especially in infants and young children. Cognitive deficits associated with CNS picornavirus infection result from injury and death of neurons that may occur due to direct viral infection or during the immune responses to virus in the brain. Previous studies have concluded that apoptosis of hippocampal neurons during picornavirus infection is a cell-autonomous event triggered by direct neuronal infection. However, these studies assessed neuron death at time points late in infection and during infections that lead to either death of the host or persistent viral infection. In contrast, many neurovirulent picornavirus infections are acute and transient, with rapid clearance of virus from the host. We provide evidence of hippocampal pathology in mice acutely infected with the Theiler's murine encephalomyelitis picornavirus. We found that CA1 pyramidal neurons exhibited several hallmarks of apoptotic death, including caspase-3 activation, DNA fragmentation, and chromatin condensation within 72 hours of infection. Critically, we also found that many of the CA1 pyramidal neurons undergoing apoptosis were not infected with virus, indicating that neuronal cell death during acute picornavirus infection of the CNS occurs in a non-cell-autonomous manner. These observations suggest that therapeutic strategies other than antiviral interventions may be useful for neuroprotection during acute CNS picornavirus infection. PMID:19608874

  13. Endoplasmic reticulum stress-regulated CXCR3 pathway mediates inflammation and neuronal injury in acute glaucoma

    PubMed Central

    Ha, Y; Liu, H; Xu, Z; Yokota, H; Narayanan, S P; Lemtalsi, T; Smith, S B; Caldwell, R W; Caldwell, R B; Zhang, W

    2015-01-01

    Acute glaucoma is a leading cause of irreversible blindness in East Asia. The mechanisms underlying retinal neuronal injury induced by a sudden rise in intraocular pressure (IOP) remain obscure. Here we demonstrate that the activation of CXCL10/CXCR3 axis, which mediates the recruitment and activation of inflammatory cells, has a critical role in a mouse model of acute glaucoma. The mRNA and protein expression levels of CXCL10 and CXCR3 were significantly increased after IOP-induced retinal ischemia. Blockade of the CXCR3 pathway by deleting CXCR3 gene significantly attenuated ischemic injury-induced upregulation of inflammatory molecules (interleukin-1β and E-selectin), inhibited the recruitment of microglia/monocyte to the superficial retina, reduced peroxynitrite formation, and prevented the loss of neurons within the ganglion cell layer. In contrast, intravitreal delivery of CXCL10 increased leukocyte recruitment and retinal cell apoptosis. Inhibition of endoplasmic reticulum (ER) stress with chemical chaperones partially blocked ischemic injury-induced CXCL10 upregulation, whereas induction of ER stress with tunicamycin enhanced CXCL10 expression in retina and primary retinal ganglion cells. Interestingly, deleting CXCR3 attenuated ER stress-induced retinal cell death. In conclusion, these results indicate that ER stress-medicated activation of CXCL10/CXCR3 pathway has an important role in retinal inflammation and neuronal injury after high IOP-induced ischemia. PMID:26448323

  14. Acute Neuronal Injury and Blood Genomic Profiles in a Nonhuman Primate Model for Ischemic Stroke

    PubMed Central

    Rodriguez-Mercado, Rafael; Ford, Gregory D; Xu, Zhenfeng; Kraiselburd, Edmundo N; Martinez, Melween I; Eterović, Vesna A; Colon, Edgar; Rodriguez, Idia V; Portilla, Peter; Ferchmin, Pedro A; Gierbolini, Lynette; Rodriguez-Carrasquillo, Maria; Powell, Michael D; Pulliam, John VK; McCraw, Casey O; Gates, Alicia; Ford, Byron D

    2012-01-01

    The goal of this study was to characterize acute neuronal injury in a novel nonhuman primate (NHP) ischemic stroke model by using multiple outcome measures. Silk sutures were inserted into the M1 segment of the middle cerebral artery of rhesus macaques to achieve permanent occlusion of the vessel. The sutures were introduced via the femoral artery by using endovascular microcatheterization techniques. Within hours after middle cerebral artery occlusion (MCAO), infarction was detectable by using diffusion-weighted MRI imaging. The infarcts expanded by 24 h after MCAO and then were detectable on T2-weighted images. The infarcts seen by MRI were consistent with neuronal injury demonstrated histologically. Neurobehavioral function after MCAO was determined by using 2 neurologic testing scales. Neurologic assessments indicated that impairment after ischemia was limited to motor function in the contralateral arm; other neurologic and behavioral parameters were largely unaffected. We also used microarrays to examine gene expression profiles in peripheral blood mononuclear cells after MCAO-induced ischemia. Several genes were altered in a time-dependent manner after MCAO, suggesting that this ischemia model may be suitable for identifying blood biomarkers associated with the presence and severity of ischemia. This NHP stroke model likely will facilitate the elucidation of mechanisms associated with acute neuronal injury after ischemia. In addition, the ability to identify candidate blood biomarkers in NHP after ischemia may prompt the development of new strategies for the diagnosis and treatment of ischemic stroke in humans. PMID:23114047

  15. Effects of melatonin on cognitive impairment and hippocampal neuronal damage in a rat model of chronic cerebral hypoperfusion

    PubMed Central

    LEE, CHOONG HYUN; PARK, JOON HA; AHN, JI HYEON; WON, MOO-HO

    2016-01-01

    Chronic cerebral hypoperfusion (CCH), which induces oxidative stress and inflammation in the brain, has previously been associated with cognitive impairment and neuronal cell damage. Melatonin is a well-known free radical scavenger and antioxidant; therefore, the present study investigated the protective effects of melatonin against CCH-induced cognitive impairment and neuronal cell death in a CCH rat model, which was generated via permanent bilateral common carotid artery occlusion (2VO). The rats in the 2VO group exhibited markedly increased escape latencies in a Morris water maze test, as compared with the rats in the sham group. In addition, increased neuronal cell damage was detected in the hippocampal CA1 region of the 2VO rats, as compared with the rats in the sham group. Treatment of the 2VO rats with melatonin significantly reduced the escape latency and neuronal cell damage, and was associated with reduced levels of malondialdehyde, microglial activation, and tumor necrosis factor-α and interleukin-1β in the ischemic hippocampus. The results of the present study suggest that melatonin may attenuate CCH-induced cognitive impairment and hippocampal neuronal cell damage by decreasing oxidative stress, microglial activation and the production of pro-inflammatory cytokines in the ischemic hippocampus. PMID:27284307

  16. The Proinflammatory RAGE/NF-κB Pathway Is Involved in Neuronal Damage and Reactive Gliosis in a Model of Sleep Apnea by Intermittent Hypoxia

    PubMed Central

    Angelo, Maria Florencia; Aguirre, Alejandra; Avilés Reyes, Rolando X.; Villarreal, Alejandro; Lukin, Jerónimo; Melendez, Matías; Vanasco, Virginia; Barker, Phil; Alvarez, Silvia; Epstein, Alberto; Jerusalinsky, Diana; Ramos, Alberto Javier

    2014-01-01

    Sleep apnea (SA) causes long-lasting changes in neuronal circuitry, which persist even in patients successfully treated for the acute effects of the disease. Evidence obtained from the intermittent hypoxia (IH) experimental model of SA has shown neuronal death, impairment in learning and memory and reactive gliosis that may account for cognitive and structural alterations observed in human patients. However, little is known about the mechanism controlling these deleterious effects that may be useful as therapeutic targets in SA. The Receptor for Advanced Glycation End products (RAGE) and its downstream effector Nuclear Factor Kappa B (NF-κB) have been related to neuronal death and astroglial conversion to the pro-inflammatory neurodegenerative phenotype. RAGE expression and its ligand S100B were shown to be increased in experimental models of SA. We here used dissociated mixed hippocampal cell cultures and male Wistar rats exposed to IH cycles and observed that NF-κB is activated in glial cells and neurons after IH. To disclose the relative contribution of the S100B/RAGE/NF-κB pathway to neuronal damage and reactive gliosis after IH we performed sequential loss of function studies using RAGE or S100B neutralizing antibodies, a herpes simplex virus (HSV)-derived amplicon vector that induces the expression of RAGEΔcyto (dominant negative RAGE) and a chemical blocker of NF-κB. Our results show that NF-κB activation peaks 3 days after IH exposure, and that RAGE or NF-κB blockage during this critical period significantly improves neuronal survival and reduces reactive gliosis. Both in vitro and in vivo, S100B blockage altered reactive gliosis but did not have significant effects on neuronal survival. We conclude that both RAGE and downstream NF-κB signaling are centrally involved in the neuronal alterations found in SA models, and that blockage of these pathways is a tempting strategy for preventing neuronal degeneration and reactive gliosis in SA. PMID:25265561

  17. Redox modulation by S-nitrosylation contributes to protein misfolding, mitochondrial dynamics, and neuronal synaptic damage in neurodegenerative diseases

    PubMed Central

    Nakamura, T; Lipton, S A

    2011-01-01

    The pathological processes of neurodegenerative disorders such as Alzheimer's and Parkinson's diseases engender synaptic and neuronal cell damage. While mild oxidative and nitrosative (nitric oxide (NO)-related) stress mediates normal neuronal signaling, excessive accumulation of these free radicals is linked to neuronal cell injury or death. In neurons, N-methyl--aspartate (NMDA) receptor (NMDAR) activation and subsequent Ca2+ influx can induce the generation of NO via neuronal NO synthase. Emerging evidence has demonstrated that S-nitrosylation, representing covalent reaction of an NO group with a critical protein thiol, mediates the vast majority of NO signaling. Analogous to phosphorylation and other posttranslational modifications, S-nitrosylation can regulate the biological activity of many proteins. Here, we discuss recent studies that implicate neuropathogenic roles of S-nitrosylation in protein misfolding, mitochondrial dysfunction, synaptic injury, and eventual neuronal loss. Among a growing number of S-nitrosylated proteins that contribute to disease pathogenesis, in this review we focus on S-nitrosylated protein-disulfide isomerase (forming SNO-PDI) and dynamin-related protein 1 (forming SNO-Drp1). Furthermore, we describe drugs, such as memantine and newer derivatives of this compound that can prevent both hyperactivation of extrasynaptic NMDARs as well as downstream pathways that lead to nitrosative stress, synaptic damage, and neuronal loss. PMID:21597461

  18. Redox modulation by S-nitrosylation contributes to protein misfolding, mitochondrial dynamics, and neuronal synaptic damage in neurodegenerative diseases.

    PubMed

    Nakamura, T; Lipton, S A

    2011-09-01

    The pathological processes of neurodegenerative disorders such as Alzheimer's and Parkinson's diseases engender synaptic and neuronal cell damage. While mild oxidative and nitrosative (nitric oxide (NO)-related) stress mediates normal neuronal signaling, excessive accumulation of these free radicals is linked to neuronal cell injury or death. In neurons, N-methyl-D-aspartate (NMDA) receptor (NMDAR) activation and subsequent Ca(2+) influx can induce the generation of NO via neuronal NO synthase. Emerging evidence has demonstrated that S-nitrosylation, representing covalent reaction of an NO group with a critical protein thiol, mediates the vast majority of NO signaling. Analogous to phosphorylation and other posttranslational modifications, S-nitrosylation can regulate the biological activity of many proteins. Here, we discuss recent studies that implicate neuropathogenic roles of S-nitrosylation in protein misfolding, mitochondrial dysfunction, synaptic injury, and eventual neuronal loss. Among a growing number of S-nitrosylated proteins that contribute to disease pathogenesis, in this review we focus on S-nitrosylated protein-disulfide isomerase (forming SNO-PDI) and dynamin-related protein 1 (forming SNO-Drp1). Furthermore, we describe drugs, such as memantine and newer derivatives of this compound that can prevent both hyperactivation of extrasynaptic NMDARs as well as downstream pathways that lead to nitrosative stress, synaptic damage, and neuronal loss. PMID:21597461

  19. Acute and late gastrointestinal toxicity after radiotherapy in prostate cancer patients: Consequential late damage

    SciTech Connect

    Heemsbergen, Wilma D. . E-mail: w.heemsbergen@nki.nl; Peeters, Stephanie T.H.; Koper, Peter; Hoogeman, Mischa S.; Lebesque, Joos V.

    2006-09-01

    Purpose: Late gastrointestinal (GI) toxicity after radiotherapy can be partly explained by late effects of acute toxicity (consequential late damage). We studied whether there is a direct relationship between acute and late GI toxicity. Patients and Methods: A total of 553 evaluable patients from the Dutch dose escalation trial (68 Gy vs. 78 Gy) were included. We defined three outcomes for acute reactions: 1) maximum Radiation Therapy Oncology Group acute toxicity, 2) maximum acute mucous discharge (AMD), and 3) maximum acute proctitis. Within a multivariable model, late endpoints (overall toxicity and five toxicity indicators) were studied as a function of acute toxicity, pretreatment symptoms, and relevant dose parameters. Results: At multivariable analysis, AMD and acute proctitis were strong predictors for overall toxicity, 'intermittent bleeding,' and 'incontinence pads' (p {<=} 0.01). For 'stools {>=}6/day' all three were strong predictors. No significant associations were found for 'severe bleeding' and 'use of steroids.' The predictive power of the dose parameters remained at the same level or became weaker for most late endpoints. Conclusions: Acute GI toxicity is an independent significant predictor of late GI toxicity. This suggests a significant consequential component in the development of late GI toxicity.

  20. Prevention of Hippocampal Neuronal Damage and Cognitive Function Deficits in Vascular Dementia by Dextromethorphan.

    PubMed

    Xu, Xiaofeng; Zhang, Bin; Lu, Kaili; Deng, Jiangshan; Zhao, Fei; Zhao, Bing-Qiao; Zhao, Yuwu

    2016-07-01

    Dextromethorphan (DM) is a non-competitive antagonist of NMDA receptors and a widely used component of cough medicine. Recently, its indication has been extended experimentally to a wide range of disorders including inflammation-mediated central nervous system disorders such as Parkinson disease (PD) and multiple sclerosis (MS). In this study, we investigate whether DM treatment has protective effects on the hippocampal neuron damage induced by bilateral occlusion of the common carotid arteries (two-vessel occlusion [2VO]), an animal model of vascular dementia (VaD). Sprague-Dawley (SD) (10 weeks of age) rats were subjected to the 2VO, and DM was injected intraperitoneally once per day for 37 days. Neuron death, glial activation, and cognitive function were assessed at 37 days after 2VO (0.2 mg/kg, i.p., "DM-0.2" and 2 mg/kg, i.p., "DM-2"). DM-2 treatment provided protection against neuronal death and glial activation in the hippocampal CA1 subfield and reduced cognitive impairment induced by 2VO in rats. The study also demonstrates that activation of the Nrf2-HO-1 pathway and upregulation of superoxide dismutase (SOD) play important roles in these effects. These results suggest that DM is effective in treating VaD and protecting against oxidative stress, which is strongly implicated in the pathogenesis of VaD. Therefore, the present study suggests that DM treatment may represent a new and promising protective strategy for treating VaD. PMID:26887382

  1. Iron-induced neuronal damage in a rat model of post-traumatic stress disorder.

    PubMed

    Zhao, Ming; Yu, Zhibo; Zhang, Yang; Huang, Xueling; Hou, Jingming; Zhao, YanGang; Luo, Wei; Chen, Lin; Ou, Lan; Li, Haitao; Zhang, Jiqiang

    2016-08-25

    Previous studies have shown that iron redistribution and deposition in the brain occurs in some neurodegenerative diseases, and oxidative damage due to abnormal iron level is a primary cause of neuronal death. In the present study, we used the single prolonged stress (SPS) model to mimic post-traumatic stress disorder (PTSD), and examined whether iron was involved in the progression of PTSD. The anxiety-like behaviors of the SPS group were assessed by the elevated plus maze (EPM) and open field tests, and iron levels were measured by inductively coupled plasma optical emission spectrometer (ICP-OES). Expression of glucocorticoid receptors and transferrin receptor 1 (TfR1) and ferritin (Fn) was detected by Western blot and immunohistochemistry in selected brain areas; TfR1 and Fn mRNA expression were detected by quantitative-polymerase chain reaction (Q-PCR). Ultrastructures of the hippocampus were observed under a transmission electron microscope. Our results showed that SPS exposure induced anxiety-like symptoms and increased the level of serum cortisol and the concentration of iron in key brain areas such as the hippocampus, prefrontal cortex, and striatum. The stress induced region-specific changes in both protein and mRNA levels of TfR1 and Fn. Moreover, swelling mitochondria and cell apoptosis were observed in neurons in brain regions with iron accumulation. We concluded that SPS stress increased iron in some cognition-related brain regions and subsequently cause neuronal injury, indicating that the iron may function in the pathology of PTSD. PMID:27208615

  2. Magnolol protects against trimethyltin-induced neuronal damage and glial activation in vitro and in vivo.

    PubMed

    Kim, Da Jung; Kim, Yong Sik

    2016-03-01

    Trimethyltin (TMT), an organotin with potent neurotoxic effects by selectively damaging to hippocampus, is used as a tool for creating an experimental model of neurodegeneration. In the present study, we investigated the protective effects of magnolol, a natural biphenolic compound, on TMT-induced neurodegeneration and glial activation in vitro and in vivo. In HT22 murine neuroblastoma cells, TMT induced necrotic/apoptotic cell death and oxidative stress, including intracellular reactive oxygen species (ROS), protein carbonylation, induction of heme oxygenase-1 (HO-1), and activation of all mitogen-activated protein kinases (MAPKs) family proteins. However, magnolol treatment significantly suppressed neuronal cell death by inhibiting TMT-mediated ROS generation and activation of JNK and p38 MAPKs. In BV-2 microglial cells, magnolol efficiently attenuated TMT-induced microglial activation via suppression of ROS generation and activation of JNK, p38 MAPKs, and nuclear factor-κB (NF-κB) signaling. In an in vivo mouse study, TMT induced massive neuronal damage and enhanced oxidative stress at day 2. We also observed a concomitant increase in glial cells and inducible nitric oxide synthase (iNOS) expression on the same day. These features of TMT toxicity were reversed by treatment of magnolol. We observed that p-JNK and p-p38 MAPK levels were increased in the mouse hippocampus at day 1 after TMT treatment and that magnolol blocked TMT-induced JNK and p38 MAPK activation. Magnolol administration prevented TMT-induced hippocampal neurodegeneration and glial activation, possibly through the regulation of TMT-mediated ROS generation and MAPK activation. PMID:26756313

  3. Protective effects of alpinae oxyphyllae fructus (Alpinia oxyphylla MIQ) water-extracts on neurons from ischemic damage and neuronal cell toxicity.

    PubMed

    Koo, Byung-Soo; Lee, Won-Chang; Chang, Young-Chae; Kim, Cheorl-Ho

    2004-02-01

    Alpinae Oxyphyllae Fructus (Alpinia oxyphylla MIQ) (Korean name Ik-Jj-In) is a medicinal plant used in Korea for the treatment of various symptoms accompanying hypertension and cerebrovascular disorders. The present study was performed to investigate the effects of Alpinae Oxyphyllae Fructus water-extracts (AOF) on a cultured primary neuron cell system, cell cytotoxicity and lipid peroxidation in Abeta treatment conditions. Cell killing was significantly enhanced by addition of increasing concentrations of Abeta. Pretreatment of AOF attenuated in cell killing enhanced by increasing concentrations of Abeta. Abeta-induced cell death was protected by the application of water extract of AOF in a dose-dependent manner, and concentrations of 50 to 100 micro g/ml had a significant effect compared to exposure of Abeta only. AOF has been shown to protect primary cultured neurons from N-methyl-D-aspartate (NMDA) receptor-mediated glutamate toxicity. The evidence indicated that AOF protects neurons against ischemia-induced cell death. Oral administration of AOF into mice prevented ischemia-induced learning disability and rescued hippocampal CA1 neurons from lethal ischemic damage. The neuroprotective action of exogenous AOF was also confirmed by counting synapses in the hippocampal CA1 region. The presence of AOF in neuron cultures did not repress a NMDA receptor-mediated increase in intracellular Ca(2+), but rescued the neurons from NO-induced death. AOF may exert its neuroprotective effect by reducing the NO-mediated formation of free radicals or antagonizing their toxicity. PMID:15022167

  4. Effects of acute and chronic administration of neurosteroid dehydroepiandrosterone sulfate on neuronal excitability in mice

    PubMed Central

    Svob Strac, Dubravka; Vlainic, Josipa; Samardzic, Janko; Erhardt, Julija; Krsnik, Zeljka

    2016-01-01

    Background Neurosteroid dehydroepiandrosterone sulfate (DHEAS) has been associated with important brain functions, including neuronal survival, memory, and behavior, showing therapeutic potential in various neuropsychiatric and cognitive disorders. However, the antagonistic effects of DHEAS on γ-amino-butyric acidA receptors and its facilitatory action on glutamatergic neurotransmission might lead to enhanced brain excitability and seizures and thus limit DHEAS therapeutic applications. The aim of this study was to investigate possible age and sex differences in the neuronal excitability of the mice following acute and chronic DHEAS administration. Methods DHEAS was administered intraperitoneally in male and female adult and old mice either acutely or repeatedly once daily for 4 weeks in a 10 mg/kg dose. To investigate the potential proconvulsant properties of DHEAS, we studied the effects of acute and chronic DHEAS treatment on picrotoxin-, pentylentetrazole-, and N-methyl-D-aspartate-induced seizures in mice. The effects of acute and chronic DHEAS administration on the locomotor activity, motor coordination, and body weight of the mice were also studied. We also investigated the effects of DHEAS treatment on [3H]flunitrazepam binding to the mouse brain membranes. Results DHEAS did not modify the locomotor activity, motor coordination, body weight, and brain [3H]flunitrazepam binding of male and female mice. The results failed to demonstrate significant effects of single- and long-term DHEAS treatment on the convulsive susceptibility in both adult and aged mice of both sexes. However, small but significant changes regarding sex differences in the susceptibility to seizures were observed following DHEAS administration to mice. Conclusion Although our findings suggest that DHEAS treatment might be safe for various potential therapeutic applications in adult as well as in old age, they also support subtle interaction of DHEAS with male and female hormonal status

  5. Influence of intensive multifunctional neurorehabilitation on neuronal oxidative damage in patients with Huntington’s disease

    PubMed Central

    Ciancarelli, Irene; De Amicis, Daniela; Di Massimo, Caterina; Sandrini, Giorgio; Pistarini, Caterina; Carolei, Antonio; Ciancarelli, Maria Giuliana Tozzi

    2015-01-01

    Summary The influence of intensive multifunctional neurorehabilitation on serum levels of Cu/Zn-superoxide dismutase (Cu/Zn-SOD), neuron-specific enolase (NSE), and 8-hydroxy-2-deoxyguanosine (8-OHdG), as markers of oxidative damage, was evaluated in symptomatic patients with Huntington’s disease (HD). Improved clinical outcome measures were observed after neurorehabilitation. Baseline levels of Cu/Zn-SOD, NSE and 8-OHdG were higher than those observed in controls. Cu/Zn-SOD and NSE values decreased after neurorehabilitation, but were still higher than those measured in controls. Cu/Zn-SOD and NSE correlated positively before (r=0.659; p=0.003) and after rehabilitation (r=0.553, p=0.017). 8-OHdG values decreased after neurorehabilitation without reaching significance when compared with baseline values (p=0.145). No correlation was observed between the measured oxidative markers and the assessed clinical outcome measures, either before or after neurorehabilitation. The findings reported in the present paper provide evidence of the effectiveness of neurorehabilitation in reducing oxidative damage in HD patients and underline the limit of serum oxidative markers for the evaluation of clinical features of HD. PMID:26214026

  6. Cannabinoids and neuronal damage: differential effects of THC, AEA and 2-AG on activated microglial cells and degenerating neurons in excitotoxically lesioned rat organotypic hippocampal slice cultures.

    PubMed

    Kreutz, Susanne; Koch, Marco; Ghadban, Chalid; Korf, Horst-Werner; Dehghani, Faramarz

    2007-01-01

    Cannabinoids (CBs) are attributed neuroprotective effects in vivo. Here, we determined the neuroprotective potential of CBs during neuronal damage in excitotoxically lesioned organotypic hippocampal slice cultures (OHSCs). OHSCs are the best characterized in vitro model to investigate the function of microglial cells in neuronal damage since blood-borne monocytes and T-lymphocytes are absent and microglial cells represent the only immunocompetent cell type. Excitotoxic neuronal damage was induced by NMDA (50 microM) application for 4 h. Neuroprotective properties of 9-carboxy-11-nor-delta-9-tetrahydrocannabinol (THC), N-arachidonoylethanolamide (AEA) or 2-arachidonoylglycerol (2-AG) in different concentrations were determined after co-application with NMDA by counting degenerating neurons identified by propidium iodide labeling (PI(+)) and microglial cells labeled by isolectin B(4) (IB(4)(+)). All three CBs used significantly decreased the number of IB(4)(+) microglial cells in the dentate gyrus but the number of PI(+) neurons was reduced only after 2-AG treatment. Application of AM630, antagonizing CB2 receptors highly expressed by activated microglial cells, did not counteract neuroprotective effects of 2-AG, but affected THC-mediated reduction of IB(4)(+) microglial cells. Our results indicate that (1) only 2-AG exerts neuroprotective effects in OHSCs; (2) reduction of IB(4)(+) microglial cells is not a neuroprotective event per se and involves other CB receptors than the CB2 receptor; (3) the discrepancy in the neuroprotective effects of CBs observed in vivo and in our in vitro model system may underline the functional relevance of invading monocytes and T-lymphocytes that are absent in OHSCs. PMID:17010339

  7. The Role of Parkin in the Differential Susceptibility of Tuberoinfundibular and Nigrostriatal Dopamine Neurons to Acute Toxicant Exposure

    PubMed Central

    Benskey, Matthew J.; Manfredsson, Fredric P.; Lookingland, Keith J.; Goudreau, John L.

    2014-01-01

    Parkinson Disease causes degeneration of nigrostriatal dopamine (DA) neurons, while tuberoinfundibular DA neurons remain unaffected. A similar pattern is observed following exposure to 1-methy-4-phenyl-1, 2, 3, 6-tetrahydropyradine (MPTP). The mechanism of tuberoinfundibular neuronal recovery from MPTP is associated with up-regulation of parkin protein. Here we tested if parkin mediates tuberoinfundibular neuronal recovery from MPTP by knocking-down parkin in tuberoinfundibular neurons using recombinant adeno-associated virus (rAAV), expressing a short hairpin RNA (shRNA) directed toward parkin. Following knockdown, axon terminal DA and tyrosine hydroxylase (TH) concentrations were analyzed 24 hours post-MPTP administration. rAAV-shRNA-mediated knockdown of endogenous parkin rendered tuberoinfundibular neurons susceptible to MPTP induced terminal DA loss, but not TH loss, within 24 hours post-MPTP. To determine if the neuroprotective benefits of parkin up-regulation could be translated to nigrostriatal neurons, rAAV expressing human parkin was injected into the substantia nigra of mice and axon terminal DA and TH concentrations were analyzed 24 hours post-MPTP. Nigral parkin over-expression prevented loss of TH in the axon terminals and soma of nigrostriatal neurons, but had no effect on terminal DA loss within 24h post-MPTP. These data show that parkin is necessary for the recovery of terminal DA concentrations within tuberoinfundibular neurons following acute MPTP administration, and parkin can rescue MPTP-induced decreases in TH within nigrostriatal neurons. PMID:25447324

  8. The role of phosphoenolpyruvate carboxykinase in neuronal steroidogenesis under acute inflammation.

    PubMed

    Sadasivam, Mohanraj; Ramatchandirin, Balamurugan; Balakrishnan, Sivasangari; Selvaraj, Karthikeyan; Prahalathan, Chidambaram

    2014-12-01

    Phosphoenolpyruvate carboxykinase (PEPCK) is a key gluconeogenic enzyme found in many tissues throughout the body including brain. In the present study, we have investigated the effect of bacterial lipopolysaccharide (LPS) on PEPCK and its role in neuronal steroidogenesis. Adult female albino rats were administered LPS (5mg/kg body weight) to induce acute inflammation. LPS administration resulted in a significant increase of PEPCK mRNA expression with concomitant increase in mRNA levels of steroidogenic acute regulatory (StAR) protein and other steroidogenic enzymes including 3β-hydroxysteroid dehydrogenase (3β-HSD), 17β-hydroxysteroid dehydrogenase (17β-HSD) and aromatase in brain tissue. Further, the inhibition of PEPCK expression by glipizide significantly decreased the mRNA expression of steroidogenic proteins and concurrently increased the mRNA levels of proinflammatory cytokines under LPS administration. The results of this study suggest a novel finding that PEPCK may have an important role in neuronal steroidogenesis; which serves as an adaptive response under inflammation. PMID:25256278

  9. Conformational Change in Transfer RNA Is an Early Indicator of Acute Cellular Damage

    PubMed Central

    Mishima, Eikan; Inoue, Chisako; Saigusa, Daisuke; Inoue, Ryusuke; Ito, Koki; Suzuki, Yusuke; Jinno, Daisuke; Tsukui, Yuri; Akamatsu, Yosuke; Araki, Masatake; Araki, Kimi; Shimizu, Ritsuko; Shinke, Haruka; Suzuki, Takehiro; Takeuchi, Yoichi; Shima, Hisato; Akiyama, Yasutoshi; Toyohara, Takafumi; Suzuki, Chitose; Saiki, Yoshikatu; Tominaga, Teiji; Miyagi, Shigehito; Kawagisihi, Naoki; Soga, Tomoyoshi; Ohkubo, Takayoshi; Yamamura, Kenichi; Imai, Yutaka; Masuda, Satohiro; Sabbisetti, Venkata; Ichimura, Takaharu; Mount, David B.; Bonventre, Joseph V.; Ito, Sadayoshi; Tomioka, Yoshihisa; Itoh, Kunihiko

    2014-01-01

    Tissue damage by oxidative stress is a key pathogenic mechanism in various diseases, including AKI and CKD. Thus, early detection of oxidative tissue damage is important. Using a tRNA-specific modified nucleoside 1-methyladenosine (m1A) antibody, we show that oxidative stress induces a direct conformational change in tRNA structure that promotes subsequent tRNA fragmentation and occurs much earlier than DNA damage. In various models of tissue damage (ischemic reperfusion, toxic injury, and irradiation), the levels of circulating tRNA derivatives increased rapidly. In humans, the levels of circulating tRNA derivatives also increased under conditions of acute renal ischemia, even before levels of other known tissue damage markers increased. Notably, the level of circulating free m1A correlated with mortality in the general population (n=1033) over a mean follow-up of 6.7 years. Compared with healthy controls, patients with CKD had higher levels of circulating free m1A, which were reduced by treatment with pitavastatin (2 mg/d; n=29). Therefore, tRNA damage reflects early oxidative stress damage, and detection of tRNA damage may be a useful tool for identifying organ damage and forming a clinical prognosis. PMID:24833129

  10. Force spectroscopy measurements show that cortical neurons exposed to excitotoxic agonists stiffen before showing evidence of bleb damage.

    PubMed

    Zou, Shan; Chisholm, Roderick; Tauskela, Joseph S; Mealing, Geoff A; Johnston, Linda J; Morris, Catherine E

    2013-01-01

    In ischemic and traumatic brain injury, hyperactivated glutamate (N-methyl-D-aspartic acid, NMDA) and sodium (Nav) channels trigger excitotoxic neuron death. Na(+), Ca(++) and H2O influx into affected neurons elicits swelling (increased cell volume) and pathological blebbing (disassociation of the plasma membrane's bilayer from its spectrin-actomyosin matrix). Though usually conflated in injured tissue, cell swelling and blebbing are distinct processes. Around an injury core, salvageable neurons could be mildly swollen without yet having suffered the bleb-type membrane damage that, by rendering channels leaky and pumps dysfunctional, exacerbates the excitotoxic positive feedback spiral. Recognizing when neuronal inflation signifies non-lethal osmotic swelling versus blebbing should further efforts to salvage injury-penumbra neurons. To assess whether the mechanical properties of osmotically-swollen versus excitotoxically-blebbing neurons might be cytomechanically distinguishable, we measured cortical neuron elasticity (gauged via atomic force microscopy (AFM)-based force spectroscopy) upon brief exposure to hypotonicity or to excitotoxic agonists (glutamate and Nav channel activators, NMDA and veratridine). Though unperturbed by solution exchange per se, elasticity increased abruptly with hypotonicity, with NMDA and with veratridine. Neurons then invariably softened towards or below the pre-treatment level, sometimes starting before the washout. The initial channel-mediated stiffening bespeaks an abrupt elevation of hydrostatic pressure linked to NMDA or Nav channel-mediated ion/H2O fluxes, together with increased [Ca(++)]int-mediated submembrane actomyosin contractility. The subsequent softening to below-control levels is consistent with the onset of a lethal level of bleb damage. These findings indicate that dissection/identification of molecular events during the excitotoxic transition from stiff/swollen to soft/blebbing is warranted and should be feasible. PMID

  11. Protective effects of total flavonoids from Flos Puerariae on retinal neuronal damage in diabetic mice

    PubMed Central

    Li, Dai; Yang, Fang; Cheng, Hongke; Liu, Chao; Sun, Ming; Wu, Kaili

    2013-01-01

    Purpose To investigate the potential protective effects of total flavonoids from Flos Puerariae (TFF) on retinal neural cells in diabetic mice. Methods C57BL/6J mice were intraperitoneally injected with streptozotocin to generate type I diabetes in a murine model, as indicated by blood glucose levels ≥11.1 mmol/l. TFF was administered intragastrically at a dose of 50, 100, or 200 mg/kg/day. After 10 weeks of administration, the mice were euthanized, and the eyes were dissected. Retinal histology was examined, and the thickness of the retina was measured. Ultrastructural changes in the retinal ganglion cells and capillary basement membrane were observed with electron microscopy. Apoptosis of retinal neural cells was determined with the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling assay. Bax and Bcl-2 expression in the retinal tissues was determined with immunohistochemical staining and western blotting. Results Compared with the diabetic mice, the blood glucose level decreased (p<0.01) and the bodyweight increased (p<0.05) in the 100 and 200 mg/kg TFF-treated groups. The thickness of the retina significantly increased (p<0.01), and the retinal capillary basement membrane (BM) thickness was reduced in the 100 and 200 mg/kg TFF-treated diabetic mice (DM). The 100 and 200 mg/kg TFF treatments also attenuated the diabetes-induced apoptosis of retinal neural cells. Consistent with these effects, TFF treatment decreased the Bax expression level and, concurrently, increased the ratio of Bcl-2 to Bax. Conclusions TFF attenuated diabetes-induced apoptosis in retinal neurons by inhibiting Bax expression and increasing the ratio of Bcl-2 to Bax, which suggests that TFF might prevent retinal neuronal damage in diabetes mellitus. PMID:24146535

  12. Modifications of the input currents on VTA dopamine neurons following acute versus chronic cocaine exposure.

    PubMed

    Michaeli, Avner; Matzner, Henry; Poltyrev, Tatyana; Yaka, Rami

    2012-03-01

    Excitatory synapses on dopamine (DA) neurons in the ventral tegmental area (VTA) are modulated following exposure to various addictive drugs, including cocaine. Previously we have shown that cocaine affects GABA(A) receptor (GABA(A)R)-mediated neurotransmission in VTA DA neurons. This finding led us to reexamine the modulation of the excitatory synapse on these neurons in response to cocaine exposure, while the activity of GABA(A)R is uninterrupted. Using rat brain slices, evoked post synaptic currents (ePSC) were monitored and inhibitors of NMDA receptor (NMDAR) and AMPA receptor (AMPAR) were gradually added to inhibitors-free bath solution. Modifications in the efficacy of the excitatory synapses were evaluated by comparing AMPAR-mediated and NMDAR-mediated currents (AMPA/NMDA ratio). The lack of GABA(A)R inhibitors enabled us to examine parallel changes in the relation between GABA(A)R-mediated and NMDAR-mediated currents (GABA(A)/NMDA ratio). First, we found that AMPA/NMDA ratio measured under complete availability of GABA(A)R, is significantly higher than the ratio measured under GABA(A)R blockade. In addition, GABA(A)/NMDA ratio, but not AMPA/NMDA ratio, is augmented a few hours following in vitro acute cocaine exposure. When measured 24 h after in vivo single cocaine injection, no change in GABA(A)/NMDA ratio was observed, however, the AMPA/NMDA ratio was found to be significantly higher. Finally, a decrease in both ratios was detected in rats repeatedly injected with cocaine. Taken together, these results lead to a better understanding of the means by which cocaine modifies synaptic inputs on VTA DA neurons. The parallel changes in GABA(A)/NMDA ratio may suggest an interaction between inhibitory and excitatory neural systems. PMID:22197515

  13. Acute oral administration of low doses of methylphenidate targets calretinin neurons in the rat septal area

    PubMed Central

    García-Avilés, Álvaro; Albert-Gascó, Héctor; Arnal-Vicente, Isabel; Elhajj, Ebtisam; Sanjuan-Arias, Julio; Sanchez-Perez, Ana María; Olucha-Bordonau, Francisco

    2015-01-01

    Methylphenidate (MPD) is a commonly administered drug to treat children suffering from attention deficit hyperactivity disorder (ADHD). Alterations in septal driven hippocampal theta rhythm may underlie attention deficits observed in these patients. Amongst others, the septo-hippocampal connections have long been acknowledged to be important in preserving hippocampal function. Thus, we wanted to ascertain if MPD administration, which improves attention in patients, could affect septal areas connecting with hippocampus. We used low and orally administered MPD doses (1.3, 2.7 and 5 mg/Kg) to rats what mimics the dosage range in humans. In our model, we observed no effect when using 1.3 mg/Kg MPD; whereas 2.7 and 5 mg/Kg induced a significant increase in c-fos expression specifically in the medial septum (MS), an area intimately connected to the hippocampus. We analyzed dopaminergic areas such as nucleus accumbens and striatum, and found that only 5 mg/Kg induced c-fos levels increase. In these areas tyrosine hydroxylase correlated well with c-fos staining, whereas in the MS the sparse tyrosine hydroxylase fibers did not overlap with c-fos positive neurons. Double immunofluorescence of c-fos with neuronal markers in the septal area revealed that co-localization with choline acethyl transferase, parvalbumin, and calbindin with c-fos did not change with MPD treatment; whereas, calretinin and c-fos double labeled neurons increased after MPD administration. Altogether, these results suggest that low and acute doses of methylphenidate primary target specific populations of caltretinin medial septal neurons. PMID:25852493

  14. Synthesis of a novel photopolymerized nanocomposite hydrogel for the treatment of acute mechanical damage to cartilage

    NASA Astrophysics Data System (ADS)

    Schlichting, Kathryn; Copeland-Johnson, Trishelle; Goodman, Matthew; Lipert, Robert; McKinley, Todd; Martin, James; Mallapragada, Surya; Lin, Zhiqun

    2011-03-01

    Posttraumatic osteoarthritis is caused by a cascade of pathobiologic and pathomechanical events starting with intraarticular fractures in the cartilage. Currently, treatment of fractures is completely focused on restoration of the macroanatomy of the joint. The premise is that restoring the macroanatomy will prevent ongoing stresses and in turn prevent cartilage degeneration. However, current treatment ignores acute mechanical damage sustained by cartilage at the time of injury. This study describes the initial development of a novel nanocomposite photopolymerizing copolymer that has potential to restore local structural integrity to acutely injured cartilage, and subsequently act as a carrier for chondrocyte-enhancing bioactive agents.

  15. EGFR mediates astragaloside IV-induced Nrf2 activation to protect cortical neurons against in vitro ischemia/reperfusion damages.

    PubMed

    Gu, Da-Min; Lu, Pei-Hua; Zhang, Ke; Wang, Xiang; Sun, Min; Chen, Guo-Qian; Wang, Qiong

    2015-02-13

    In this study, we tested the potential role of astragaloside IV (AS-IV) against oxygen and glucose deprivation/re-oxygenation (OGD/R)-induced damages in murine cortical neurons, and studied the associated signaling mechanisms. AS-IV exerted significant neuroprotective effects against OGD/R by reducing reactive oxygen species (ROS) accumulation, thereby attenuating oxidative stress and neuronal cell death. We found that AS-IV treatment in cortical neurons resulted in NF-E2-related factor 2 (Nrf2) signaling activation, evidenced by Nrf2 Ser-40 phosphorylation, and its nuclear localization, as well as transcription of antioxidant-responsive element (ARE)-regulated genes: heme oxygenase-1 (HO-1), NAD(P)H:quinone oxidoreductase 1 (NQO-1) and sulphiredoxin 1 (SRXN-1). Knockdown of Nrf2 through lentiviral shRNAs prevented AS-IV-induced ARE genes transcription, and abolished its anti-oxidant and neuroprotective activities. Further, we discovered that AS-IV stimulated heparin-binding-epidermal growth factor (HB-EGF) release to trans-activate epidermal growth factor receptor (EGFR) in cortical neurons. Blockage or silencing EGFR prevented Nrf2 activation by AS-IV, thus inhibiting AS-IV-mediated anti-oxidant and neuroprotective activities against OGD/R. In summary, AS-IV protects cortical neurons against OGD/R damages through activating of EGFR-Nrf2 signaling. PMID:25582778

  16. A Comparison of the Effects of Neuronal Nitric Oxide Synthase and Inducible Nitric Oxide Synthase Inhibition on Cartilage Damage

    PubMed Central

    Gokay, Nevzat Selim; Yilmaz, Ibrahim; Demiroz, Ahu Senem; Gokce, Alper; Dervisoglu, Sergülen; Gokay, Banu Vural

    2016-01-01

    The objective of this study was to investigate the effects of selective inducible nitric oxide synthase and neuronal nitric oxide synthase inhibitors on cartilage regeneration. The study involved 27 Wistar rats that were divided into five groups. On Day 1, both knees of 3 rats were resected and placed in a formalin solution as a control group. The remaining 24 rats were separated into 4 groups, and their right knees were surgically damaged. Depending on the groups, the rats were injected with intra-articular normal saline solution, neuronal nitric oxide synthase inhibitor 7-nitroindazole (50 mg/kg), inducible nitric oxide synthase inhibitor amino-guanidine (30 mg/kg), or nitric oxide precursor L-arginine (200 mg/kg). After 21 days, the right and left knees of the rats were resected and placed in formalin solution. The samples were histopathologically examined by a blinded evaluator and scored on 8 parameters. Although selective neuronal nitric oxide synthase inhibition exhibited significant (P = 0.044) positive effects on cartilage regeneration following cartilage damage, it was determined that inducible nitric oxide synthase inhibition had no statistically significant effect on cartilage regeneration. It was observed that the nitric oxide synthase activation triggered advanced arthrosis symptoms, such as osteophyte formation. The fact that selective neuronal nitric oxide synthase inhibitors were observed to have mitigating effects on the severity of the damage may, in the future, influence the development of new agents to be used in the treatment of cartilage disorders. PMID:27382570

  17. Combined exposure to simulated microgravity and acute or chronic radiation reduces neuronal network integrity and cell survival

    NASA Astrophysics Data System (ADS)

    Benotmane, Rafi

    During orbital or interplanetary space flights, astronauts are exposed to cosmic radiations and microgravity. This study aimed at assessing the effect of these combined conditions on neuronal network density, cell morphology and survival, using well-connected mouse cortical neuron cultures. To this end, neurons were exposed to acute low and high doses of low LET (X-rays) radiation or to chronic low dose-rate of high LET neutron irradiation (Californium-252), under the simulated microgravity generated by the Random Positioning Machine (RPM, Dutch space). High content image analysis of cortical neurons positive for the neuronal marker βIII-tubulin unveiled a reduced neuronal network integrity and connectivity, and an altered cell morphology after exposure to acute/chronic radiation or to simulated microgravity. Additionally, in both conditions, a defect in DNA-repair efficiency was revealed by an increased number of γH2AX-positive foci, as well as an increased number of Annexin V-positive apoptotic neurons. Of interest, when combining both simulated space conditions, we noted a synergistic effect on neuronal network density, neuronal morphology, cell survival and DNA repair. Furthermore, these observations are in agreement with preliminary gene expression data, revealing modulations in cytoskeletal and apoptosis-related genes after exposure to simulated microgravity. In conclusion, the observed in vitro changes in neuronal network integrity and cell survival induced by space simulated conditions provide us with mechanistic understanding to evaluate health risks and the development of countermeasures to prevent neurological disorders in astronauts over long-term space travels. Acknowledgements: This work is supported partly by the EU-FP7 projects CEREBRAD (n° 295552)

  18. N-Adamantyl-4-methylthiazol-2-amine suppresses amyloid β-induced neuronal oxidative damage in cortical neurons.

    PubMed

    Cho, Chang Hun; Kim, Eun-A; Kim, Jiae; Choi, Soo Young; Yang, Seung-Ju; Cho, Sung-Woo

    2016-06-01

    Recently, we have reported that N-adamantyl-4-methylthiazol-2-amine (KHG26693) successfully reduced the production of oxidative stress in streptozotocin-induced diabetic rats and lipopolysaccharide-induced BV-2 microglial cells by increasing their antioxidant capacity. However, antioxidative effects of KHG26693 against Aβ (Aβ)-induced oxidative stress have not yet been reported. In the present study, we further investigated the antioxidative function of KHG26693 in Aβ-mediated primary cultured cortical neurons. We showed here that KHG26693 attenuated Aβ-induced cytotoxicity, increase of Bax/Bcl-2 ratio, elevation of caspase-3 expression, and impairment of mitochondrial membrane potential in cultured primary cortical neurons. KHG26693 also decreases the Aβ-mediated formation of malondialdehyde, reactive oxygen species, and NO production by decreasing nitric oxide synthase (iNOS) and NADPH oxidase level. Moreover, KHG26693 suppress the Aβ-induced oxidative stress through a possible mechanism involving attenuation of GSH and antioxidant enzyme activities such as glutathione reductase and glutathione peroxidase (GPx). Finally, pretreatment of cortical neurons with KHG26693 significantly reduced the Aβ-induced protein oxidation and nitration. To our knowledge, this is the first report, showing that KHG26693 significantly attenuates Aβ-induced oxidative stress in primary cortical neurons, and may prove attractive strategies to reduce Aβ-induced neural cell death. PMID:27002191

  19. Neuronal NOS and cyclooxygenase-2 contribute to DNA damage in a mouse model of Parkinson’s disease

    PubMed Central

    Hoang, Tuan; Choi, Dong-Kug; Nagai, Makiko; Wu, Du-Chu; Nagata, Tetsuya; Prou, Delphine; Wilson, Glenn L.; Vila, Miquel; Jackson-Lewis, Vernice; Dawson, Valina L.; Dawson, Ted M.; Chesselet, Marie-Françoise; Przedborski, Serge

    2013-01-01

    DNA damage is a proposed pathogenic factor in neurodegenerative disorders such as Parkinson’s disease. To probe the underpinning mechanism of such neuronal perturbation, we sought to produce an experimental model of DNA damage. We thus first assessed by in situ nick translation and emulsion autoradiography in the mouse brain the effect of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP; 4 × 20mg/kg, i.p., every 2 hours), a neurotoxin known to produce a model of Parkinson’s disease, on DNA. Here we show that DNA strand breaks occur in vivo in this mouse model of Parkinson’s disease with kinetics and a topography that parallel the degeneration of substantia nigra neurons, as assessed by FluoroJade-labeling. Previously, nitric oxide synthase (NOS) and cyclooxygenase-2 (Cox-2) were found to modulate MPTP-induced dopaminergic neuronal death. We thus assessed the contribution of these enzymes to DNA damage in mice lacking either neuronal nitric oxide synthase (nNOS), inducible nitric oxide synthase (iNOS), or Cox-2. We found that the lack of Cox-2 and of nNOS, but not of iNOS activity, attenuate MPTP-related DNA damage. We also found that not only nuclear, but mitochondrial DNA as well is a target for the MPTP insult. These results suggest that the loss of genomic integrity can be triggered by the concerted actions of nNOS and Cox-2, and provide further support to the view that DNA damage may contribute to the neurodegenerative process in PD. PMID:19616617

  20. Acute upregulation of neuronal mitochondrial type-1 cannabinoid receptor and it's role in metabolic defects and neuronal apoptosis after TBI.

    PubMed

    Xu, Zhen; Lv, Xiao-Ai; Dai, Qun; Ge, Yu-Qing; Xu, Jie

    2016-01-01

    Metabolic defects and neuronal apoptosis initiated by traumatic brain injury (TBI) contribute to subsequent neurodegeneration. They are all regulated by mechanisms centered around mitochondrion. Type-1 cannabinoid receptor (CB1) is a G-protein coupled receptor (GPCR) enriched on neuronal plasma membrane. Recent evidences point to the substantial presence of CB1 receptors on neuronal mitochondrial outer membranes (mtCB1) and the activation of mtCB1 influences aerobic respiration via inhibiting mitochondrial cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA)/complex I pathway. The expression and role of neuronal mtCB1 under TBI are unknown. Using TBI models of cultured neurons, wild type and CB1 knockout mice, we found mtCB1 quickly upregulated after TBI. Activation of mtCB1 promoted metabolic defects accompanied with ATP shortage but protected neurons from apoptosis. Selective activation of plasma membrane CB1 showed no effects on neuronal metabolism and apoptosis. Activation of mtCB1 receptors inhibited mitochondrial cAMP/PKA/complex I and resulted in exacerbated metabolic defects accompanied with a higher ratio of ATP reduction to oxygen consumption decrease as well as neuronal apoptosis. Further research found the remarkable accumulation of protein kinase B (AKT) on neuronal mitochondria following TBI and the activation of mtCB1 upregulated mitochondrial AKT/complex V activity. Upregulation of mitochondrial AKT/complex V activity showed anti-apoptosis effects and alleviated ATP shortage in metabolic defects. Taken together, we have identified mtCB1 quickly upregulate after TBI and a dual role the mtCB1 might play in metabolic defects and neuronal apoptosis initiated by TBI: the inhibition of mitochondrial cAMP/PKA/complex I aggravates metabolic defects, energy insufficiency as well as neuronal apoptosis, but the coactivation of mitochondrial AKT/complex V mitigates energy insufficiency and neuronal apoptosis. PMID:27485212

  1. Vorinostat Induces Reactive Oxygen Species and DNA Damage in Acute Myeloid Leukemia Cells

    PubMed Central

    Pettersson, Filippa; Retrouvey, Hélène; Skoulikas, Sophia; Miller, Wilson H.

    2011-01-01

    Histone deacetylase inhibitors (HDACi) are promising anti-cancer agents, however, their mechanisms of action remain unclear. In acute myeloid leukemia (AML) cells, HDACi have been reported to arrest growth and induce apoptosis. In this study, we elucidate details of the DNA damage induced by the HDACi vorinostat in AML cells. At clinically relevant concentrations, vorinostat induces double-strand breaks and oxidative DNA damage in AML cell lines. Additionally, AML patient blasts treated with vorinostat display increased DNA damage, followed by an increase in caspase-3/7 activity and a reduction in cell viability. Vorinostat-induced DNA damage is followed by a G2-M arrest and eventually apoptosis. We found that pre-treatment with the antioxidant N-acetyl cysteine (NAC) reduces vorinostat-induced DNA double strand breaks, G2-M arrest and apoptosis. These data implicate DNA damage as an important mechanism in vorinostat-induced growth arrest and apoptosis in both AML cell lines and patient-derived blasts. This supports the continued study and development of vorinostat in AMLs that may be sensitive to DNA-damaging agents and as a combination therapy with ionizing radiation and/or other DNA damaging agents. PMID:21695163

  2. Motor-Neuron Pool Excitability of the Lower Leg Muscles After Acute Lateral Ankle Sprain

    PubMed Central

    Klykken, Lindsey W.; Pietrosimone, Brian G.; Kim, Kyung-Min; Ingersoll, Christopher D.; Hertel, Jay

    2011-01-01

    Context: Neuromuscular deficits in leg muscles that are associated with arthrogenic muscle inhibition have been reported in people with chronic ankle instability, yet whether these neuromuscular alterations are present in individuals with acute sprains is unknown. Objective: To compare the effect of acute lateral ankle sprain on the motor-neuron pool excitability (MNPE) of injured leg muscles with that of uninjured contralateral leg muscles and the leg muscles of healthy controls. Design: Case-control study. Setting: Laboratory. Patients or Other Participants: Ten individuals with acute ankle sprains (6 females, 4 males; age = 19.2 ± 3.8 years, height = 169.4 ± 8.5 cm, mass = 66.3 ±11.6 kg) and 10 healthy individuals (6 females, 4 males; age = 20.6 ± 4.0 years, height = 169.9 ± 10.6 cm, mass = 66.3 ± 10.2 kg) participated. Intervention(s): The independent variables were group (acute ankle sprain, healthy) and limb (injured, uninjured). Separate dependent t tests were used to determine differences in MNPE between legs. Main Outcome Measure(s): The MNPE of the soleus, fibularis longus, and tibialis anterior was measured by the maximal Hoffmann reflex (Hmax) and maximal muscle response (Mmax) and was then normalized using the Hmax:Mmax ratio. Results: The soleus MNPE in the ankle-sprain group was higher in the injured limb (Hmax:Mmax = 0.63; 95% confidence interval [CI], 0.46, 0.80) than in the uninjured limb (Hmax:Mmax = 0.47; 95% CI, 0.08, 0.93) (t6 = 3.62, P = .01). In the acute ankle-sprain group, tibialis anterior MNPE tended to be lower in the injured ankle (Hmax:Mmax = 0.06; 95% CI, 0.01, 0.10) than in the uninjured ankle (Hmax:Mmax = 0.22; 95% CI, 0.09, 0.35), but this finding was not different (t9 = −2.01, P = .07). No differences were detected between injured (0.22; 95% CI, 0.14, 0.29) and uninjured (0.25; 95% CI, 0.12, 0.38) ankles for the fibularis longus in the ankle-sprain group (t9 = −0.739, P = .48). We found no side-to-side differences in

  3. Acute liver damage induced by 2-nitropropane in rats: effect of diphenyl diselenide on antioxidant defenses.

    PubMed

    Borges, Lysandro P; Nogueira, Cristina Wayne; Panatieri, Rodrigo B; Rocha, João Batista Teixeira; Zeni, Gilson

    2006-03-25

    The effect of post-treatment with diphenyl diselenide on liver damage induced by 2-nitropropane (2-NP) was examined in male rats. Rats were pre-treated with a single dose of 2-NP (100 mg/kg body weight dissolved in canola oil). Afterward, the animals were post-treated with a dose of diphenyl diselenide (10, 50 or 100 micromol/kg). The parameters that indicate tissue damage such as liver histopathology, plasma aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT), urea and creatinine were determined. Since the liver damage induced by 2-NP is related to oxidative damage, lipid peroxidation, superoxide dismutase (SOD), catalase (CAT) and ascorbic acid level were also evaluated. Diphenyl diselenide (50 and 100 micromol/kg) effectively restored the increase of ALT and AST activities and urea level when compared to the 2-NP group. At the higher dose, diphenyl diselenide decreased GGT activity. Treatment with diphenyl diselenide, at all doses, effectively ameliorated the increase of hepatic and renal lipid peroxidation when compared to 2-NP group. 2-NP reduced CAT activity and neither alter SOD activity nor ascorbic acid level. This study points out the involvement of CAT activity in 2-NP-induced acute liver damage and suggests that the post-treatment with diphenyl diselenide was effective in restoring the hepatic damage induced by 2-NP. PMID:16445897

  4. Neuroprotective effect of acute melatonin treatment on hippocampal neurons against irradiation by inhibition of caspase-3

    PubMed Central

    LI, JIANGUO; ZHANG, GUOWEI; MENG, ZHUANGZHI; WANG, LINGZHAN; LIU, HAIYING; LIU, QIANG; BUREN, BATU

    2016-01-01

    Neuronal cell apoptosis is associated with various factors that induce neurological damage, including radiation exposure. When administered prior to exposure to radiation, a protective agent may prevent cellular and molecular injury. The present study aimed to investigate whether melatonin exerts a neuroprotective effect by inhibiting the caspase cell death pathway. Male Sprague-Dawley rats were administered melatonin (100 mg/kg body weight) 30 min prior to radiation exposure in red light during the evening. In order to elucidate whether melatonin has a neuroprotective role, immunohistochemistry, terminal deoxynucleotidyl transferase dUTP nick-end labeling, Nissl staining, reverse transcription-quantitative polymerase chain reaction, reactive oxygen species analysis and western blotting were performed. At 24 h post-melatonin treatment, caspase-3 mRNA and protein expression levels were significantly decreased. These results demonstrated that melatonin may protect hippocampal neurons via the inhibition of caspase-3 when exposed to irradiation. Therefore, caspase-3 inhibition serves a neuroprotective and antioxidant role in the interventional treatment of melatonin. The results of the present study suggested that melatonin may have a potential therapeutic effect against irradiation; however, further studies are required in order to elucidate the underlying antioxidant mechanisms. PMID:27313671

  5. Repair of traumatic plasmalemmal damage to neurons and other eukaryotic cells

    PubMed Central

    Bittner, George D.; Spaeth, Christopher S.; Poon, Andrew D.; Burgess, Zachary S.; McGill, Christopher H.

    2016-01-01

    The repair (sealing) of plasmalemmal damage, consisting of small holes to complete transections, is critical for cell survival, especially for neurons that rarely regenerate cell bodies. We first describe and evaluate different measures of cell sealing. Some measures, including morphological/ultra-structural observations, membrane potential, and input resistance, provide very ambiguous assessments of plasmalemmal sealing. In contrast, measures of ionic current flow and dye barriers can, if appropriately used, provide more accurate assessments. We describe the effects of various substances (calcium, calpains, cytoskeletal proteins, ESCRT proteins, mUNC-13, NSF, PEG) and biochemical pathways (PKA, PKC, PLC, Epac, cytosolic oxidation) on plasmalemmal sealing probability, and suggest that substances, pathways, and cellular events associated with plasmalemmal sealing have undergone a very conservative evolution. During sealing, calcium ion influx mobilizes vesicles and other membranous structures (lysosomes, mitochondria, etc.) in a continuous fashion to form a vesicular plug that gradually restricts diffusion of increasingly smaller molecules and ions over a period of seconds to minutes. Furthermore, we find no direct evidence that sealing occurs through the collapse and fusion of severed plasmalemmal leaflets, or in a single step involving the fusion of one large wound vesicle with the nearby, undamaged plasmalemma. We describe how increases in perikaryal calcium levels following axonal transection account for observations that cell body survival decreases the closer an axon is transected to the perikaryon. Finally, we speculate on relationships between plasmalemmal sealing, Wallerian degeneration, and the ability of polyethylene glycol (PEG) to seal cell membranes and rejoin severed axonal ends – an important consideration for the future treatment of trauma to peripheral nerves. A better knowledge of biochemical pathways and cytoplasmic structures involved in

  6. Heme oxygenase-1 induction prevents neuronal damage triggered during mitochondrial inhibition: role of CO and bilirubin.

    PubMed

    Orozco-Ibarra, Marisol; Estrada-Sánchez, Ana María; Massieu, Lourdes; Pedraza-Chaverrí, José

    2009-06-01

    Heme oxygenase (HO) catalyzes the breakdown of heme to iron, carbon monoxide (CO), and biliverdin, the latter being further reduced to bilirubin (BR). A protective role of the inducible isoform, HO-1, has been described in pathological conditions associated with reactive oxygen species (ROS) and oxidative damage. The aim of this study was to investigate the role of HO-1 in the neurotoxicity induced by the mitochondrial toxin 3-nitropropionic acid (3-NP) in primary cultures of cerebellar granule neurons (CGNs). Toxicity of 3-NP is associated with ROS production, and this metabolic toxin has been used to mimic pathological conditions such as Huntington's disease. We found that cell death caused by 3-NP exposure was exacerbated by inhibition of HO with tin mesoporphyrin (SnMP). In addition, HO-1 up-regulation induced by the exposure to cobalt protoporphyrin (CoPP) before the incubation with 3-NP, prevented the cell death and the increase in ROS induced by 3-NP. Interestingly, addition of SnMP to CoPP-pretreated CGNs exposed to 3-NP, abolished the protective effect of CoPP suggesting that HO activity was responsible for this protective effect. This was additionally supported by the fact that CORM-2, a CO-releasing molecule, and BR, were able to protect against cell death and the increase in ROS induced by 3-NP. Our data clearly show that HO-1 elicits in CGNs a neuroprotective action against the neurotoxicity of 3-NP and that CO and BR may be involved, at least in part, in this protective effect. The present results increase our knowledge about the role of HO-1 in neuropathological conditions. PMID:19063990

  7. Pre-B-cell colony-enhancing factor protects against apoptotic neuronal death and mitochondrial damage in ischemia.

    PubMed

    Wang, Xiaowan; Li, Hailong; Ding, Shinghua

    2016-01-01

    We previously demonstrated that Pre-B-cell colony-enhancing factor (PBEF), also known as nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme in mammalian NAD(+) biosynthesis pathway, plays a brain and neuronal protective role in ischemic stroke. In this study, we further investigated the mechanism of its neuroprotective effect after ischemia in the primary cultured mouse cortical neurons. Using apoptotic cell death assay, fluorescent imaging, molecular biology, mitochondrial biogenesis measurements and Western blotting analysis, our results show that the overexpression of PBEF in neurons can significantly promote neuronal survival, reduce the translocation of apoptosis inducing factor (AIF) from mitochondria to nuclei and inhibit the activation of capase-3 after glutamate-induced excitotoxicity. We further found that the overexpression of PBEF can suppress glutamate-induced mitochondrial fragmentation, the loss of mitochondrial DNA (mtDNA) content and the reduction of PGC-1 and NRF-1 expressions. Furthermore, these beneficial effects by PBEF are dependent on its enzymatic activity of NAD(+) synthesis. In summary, our study demonstrated that PBEF ameliorates ischemia-induced neuronal death through inhibiting caspase-dependent and independent apoptotic signaling pathways and suppressing mitochondrial damage and dysfunction. Our study provides novel insights into the mechanisms underlying the neuroprotective effect of PBEF, and helps to identify potential targets for ischemic stroke therapy. PMID:27576732

  8. Pre-B-cell colony-enhancing factor protects against apoptotic neuronal death and mitochondrial damage in ischemia

    PubMed Central

    Wang, Xiaowan; Li, Hailong; Ding, Shinghua

    2016-01-01

    We previously demonstrated that Pre-B-cell colony-enhancing factor (PBEF), also known as nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme in mammalian NAD+ biosynthesis pathway, plays a brain and neuronal protective role in ischemic stroke. In this study, we further investigated the mechanism of its neuroprotective effect after ischemia in the primary cultured mouse cortical neurons. Using apoptotic cell death assay, fluorescent imaging, molecular biology, mitochondrial biogenesis measurements and Western blotting analysis, our results show that the overexpression of PBEF in neurons can significantly promote neuronal survival, reduce the translocation of apoptosis inducing factor (AIF) from mitochondria to nuclei and inhibit the activation of capase-3 after glutamate-induced excitotoxicity. We further found that the overexpression of PBEF can suppress glutamate-induced mitochondrial fragmentation, the loss of mitochondrial DNA (mtDNA) content and the reduction of PGC-1 and NRF-1 expressions. Furthermore, these beneficial effects by PBEF are dependent on its enzymatic activity of NAD+ synthesis. In summary, our study demonstrated that PBEF ameliorates ischemia-induced neuronal death through inhibiting caspase-dependent and independent apoptotic signaling pathways and suppressing mitochondrial damage and dysfunction. Our study provides novel insights into the mechanisms underlying the neuroprotective effect of PBEF, and helps to identify potential targets for ischemic stroke therapy. PMID:27576732

  9. Acute radiation-induced pulmonary damage: a clinical study on the response to fractionated radiation therapy.

    PubMed

    Mah, K; Van Dyk, J; Keane, T; Poon, P Y

    1987-02-01

    Acute radiation-induced pulmonary damage can be a significant cause of morbidity in radiation therapy of the thorax. A prospective, clinical study was conducted to obtain dose-response data on acute pulmonary damage caused by fractionated radiation therapy. The endpoint was a visible increase in lung density within the irradiated volume on a computed tomographic (CT) examination as observed independently by three diagnostic radiologists. Fifty-four patients with various malignancies of the thorax completed the study. CT chest scans were taken before and at preselected times following radiotherapy. To represent different fractionation schedules of equivalent biological effect, the estimated single dose (ED) model, ED = D X N-0.377 X T-0.058 was used in which D was the average lung dose within the high dose region in cGy, N was the number of fractions, and T was the overall treatment time in days. Patients were grouped according to ED and the percent incidence of pulmonary damage for each group was determined. Total average lung doses ranged from 29.8 Gy to 53.6 Gy given in 10 to 30 fractions over a range of 12 to 60 days. Five patient groups with incidence ranging from 30% (ED of 930) to 90% (ED of 1150) were obtained. The resulting dose-response curve predicted a 50% incidence level at an ED value (ED50) of 1000 +/- 40 ED units. This value represents fractionation schedules equivalent to a total average lung dose of 32.9 Gy given in 15 fractions over 19 days. Over the linear portion of the dose-response curve, a 5% increase in ED (or total dose if N and T remain constant), predicts a 12% increase in the incidence of acute radiation-induced pulmonary damage. PMID:3818385

  10. Enteric Neuronal Damage, Intramuscular Denervation and Smooth Muscle Phenotype Changes as Mechanisms of Chagasic Megacolon: Evidence from a Long-Term Murine Model of Tripanosoma cruzi Infection

    PubMed Central

    Duz, Ana Luiza Cassin; Cartelle, Christiane Teixeira; Noviello, Maria de Lourdes; Veloso, Vanja Maria; Bahia, Maria Terezinha; Almeida-Leite, Camila Megale; Arantes, Rosa Maria Esteves

    2016-01-01

    We developed a novel murine model of long-term infection with Trypanosoma cruzi with the aim to elucidate the pathogenesis of megacolon and the associated adaptive and neuromuscular intestinal disorders. Our intent was to produce a chronic stage of the disease since the early treatment should avoid 100% mortality of untreated animals at acute phase. Treatment allowed animals to be kept infected and alive in order to develop the chronic phase of infection with low parasitism as in human disease. A group of Swiss mice was infected with the Y strain of T. cruzi. At the 11th day after infection, a sub-group was euthanized (acute-phase group) and another sub-group was treated with benznidazole and euthanized 15 months after infection (chronic-phase group). Whole colon samples were harvested and used for studying the histopathology of the intestinal smooth muscle and the plasticity of the enteric nerves. In the acute phase, all animals presented inflammatory lesions associated with intense and diffuse parasitism of the muscular and submucosa layers, which were enlarged when compared with the controls. The occurrence of intense degenerative inflammatory changes and increased reticular fibers suggests inflammatory-induced necrosis of muscle cells. In the chronic phase, parasitism was insignificant; however, the architecture of Aüerbach plexuses was focally affected in the inflamed areas, and a significant decrease in the number of neurons and in the density of intramuscular nerve bundles was detected. Other changes observed included increased thickness of the colon wall, diffuse muscle cell hypertrophy, and increased collagen deposition, indicating early fibrosis in the damaged areas. Mast cell count significantly increased in the muscular layers. We propose a model for studying the long-term (15 months) pathogenesis of Chagasic megacolon in mice that mimics the human disease, which persists for several years and has not been fully elucidated. We hypothesize that the long

  11. Enteric Neuronal Damage, Intramuscular Denervation and Smooth Muscle Phenotype Changes as Mechanisms of Chagasic Megacolon: Evidence from a Long-Term Murine Model of Tripanosoma cruzi Infection.

    PubMed

    Campos, Camila França; Cangussú, Silvia Dantas; Duz, Ana Luiza Cassin; Cartelle, Christiane Teixeira; Noviello, Maria de Lourdes; Veloso, Vanja Maria; Bahia, Maria Terezinha; Almeida-Leite, Camila Megale; Arantes, Rosa Maria Esteves

    2016-01-01

    We developed a novel murine model of long-term infection with Trypanosoma cruzi with the aim to elucidate the pathogenesis of megacolon and the associated adaptive and neuromuscular intestinal disorders. Our intent was to produce a chronic stage of the disease since the early treatment should avoid 100% mortality of untreated animals at acute phase. Treatment allowed animals to be kept infected and alive in order to develop the chronic phase of infection with low parasitism as in human disease. A group of Swiss mice was infected with the Y strain of T. cruzi. At the 11th day after infection, a sub-group was euthanized (acute-phase group) and another sub-group was treated with benznidazole and euthanized 15 months after infection (chronic-phase group). Whole colon samples were harvested and used for studying the histopathology of the intestinal smooth muscle and the plasticity of the enteric nerves. In the acute phase, all animals presented inflammatory lesions associated with intense and diffuse parasitism of the muscular and submucosa layers, which were enlarged when compared with the controls. The occurrence of intense degenerative inflammatory changes and increased reticular fibers suggests inflammatory-induced necrosis of muscle cells. In the chronic phase, parasitism was insignificant; however, the architecture of Aüerbach plexuses was focally affected in the inflamed areas, and a significant decrease in the number of neurons and in the density of intramuscular nerve bundles was detected. Other changes observed included increased thickness of the colon wall, diffuse muscle cell hypertrophy, and increased collagen deposition, indicating early fibrosis in the damaged areas. Mast cell count significantly increased in the muscular layers. We propose a model for studying the long-term (15 months) pathogenesis of Chagasic megacolon in mice that mimics the human disease, which persists for several years and has not been fully elucidated. We hypothesize that the long

  12. The Effects of NMDA Antagonists on Neuronal Activity in Cat Spinal Cord Evoked by Acute Inflammation in the Knee Joint.

    PubMed

    Schaible, Hans-Georg; Grubb, Blair D.; Neugebauer, Volker; Oppmann, Maria

    1991-01-01

    In alpha-chloralose-anaesthetized, spinalized cats we examined the effects of NMDA antagonists on the discharges of 71 spinal neurons which had afferent input from the knee joint. These neurons were rendered hyperexcitable by acute arthritis in the knee induced by kaolin and carrageenan. They were located in the deep dorsal and ventral horn and some of them had ascending axons. The N-methyl-d-aspartate (NMDA) antagonists ketamine and d-2-amino-5-phosphonovalerate (AP5), were administered ionophoretically, and ketamine was also administered intravenously. In some of the experiments the antagonists were tested against the agonists NMDA and quisqualate. The effects of the NMDA antagonists consisted of a significant reduction in the resting activity of neurons and/or the responses of the same neurons to mechanical stimulation of the inflamed knee. Intravenous ketamine was most effective in suppressing the resting and mechanically evoked activity in 25 of 26 neurons tested. Ionophoretically applied ketamine had a suppressive effect in 11 of 21 neurons, and AP5 decreased activity in 17 of 24 cells. The reduction in the resting and/or the mechanically evoked discharges was achieved with doses of the antagonists which suppressed the responses to NMDA but not those to quisqualate. These results suggest that NMDA receptors are involved in the enhanced responses and basal activity of spinal neurons induced by inflammation in the periphery. PMID:12106256

  13. Protective effects of antioxidants and anti-inflammatory agents against manganese-induced oxidative damage and neuronal injury

    SciTech Connect

    Milatovic, Dejan; Gupta, Ramesh C.; Yu, Yingchun; Zaja-Milatovic, Snjezana; Aschner, Michael

    2011-11-15

    Exposure to excessive manganese (Mn) levels leads to neurotoxicity, referred to as manganism, which resembles Parkinson's disease (PD). Manganism is caused by neuronal injury in both cortical and subcortical regions, particularly in the basal ganglia. The basis for the selective neurotoxicity of Mn is not yet fully understood. However, several studies suggest that oxidative damage and inflammatory processes play prominent roles in the degeneration of dopamine-containing neurons. In the present study, we assessed the effects of Mn on reactive oxygen species (ROS) formation, changes in high-energy phosphates and associated neuronal dysfunctions both in vitro and in vivo. Results from our in vitro study showed a significant (p < 0.01) increase in biomarkers of oxidative damage, F{sub 2}-isoprostanes (F{sub 2}-IsoPs), as well as the depletion of ATP in primary rat cortical neurons following exposure to Mn (500 {mu}M) for 2 h. These effects were protected when neurons were pretreated for 30 min with 100 of an antioxidant, the hydrophilic vitamin E analog, trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid), or an anti-inflammatory agent, indomethacin. Results from our in vivo study confirmed a significant increase in F{sub 2}-IsoPs levels in conjunction with the progressive spine degeneration and dendritic damage of the striatal medium spiny neurons (MSNs) of mice exposed to Mn (100 mg/kg, s.c.) 24 h. Additionally, pretreatment with vitamin E (100 mg/kg, i.p.) or ibuprofen (140 {mu}g/ml in the drinking water for two weeks) attenuated the Mn-induced increase in cerebral F{sub 2}-IsoPs? and protected the MSNs from dendritic atrophy and dendritic spine loss. Our findings suggest that the mediation of oxidative stress/mitochondrial dysfunction and the control of alterations in biomarkers of oxidative injury, neuroinflammation and synaptodendritic degeneration may provide an effective, multi-pronged therapeutic strategy for protecting dysfunctional dopaminergic

  14. Acute exposure to ethanol potentiates human immunodeficiency virus type 1 Tat-induced Ca(2+) overload and neuronal death in cultured rat cortical neurons.

    PubMed

    Brailoiu, Eugen; Brailoiu, G Cristina; Mameli, Giuseppe; Dolei, Antonina; Sawaya, Bassel E; Dun, Nae J

    2006-02-01

    A significant number of human immunodeficiency virus type 1 (HIV-1)-infected patients are alcoholics. Either alcohol or HIV alone induces morphological and functional damage to the nervous system. HIV-1 Tat is a potent transcriptional activator of the viral promoter, with the ability to modulate a number of cellular regulatory circuits including apoptosis and to cause neuronal injury. To further evaluate the involvement of alcohol in neuronal injury, the authors examined the effect of ethanol on Tat-induced calcium responses in rat cerebral cortical neurons, using microfluorimetric calcium determination. HIV Tat protein (10 or 500 nM) elicited two types of calcium responses in cortical neurons: a fast-onset, short-lasting response and a slow-onset, sustained response. The responses were concentration-dependent and diminished in calcium-free saline. A short exposure to ethanol (50 mM) potentiated both types of calcium response, which was markedly decreased when the cells were pretreated with BAPTA-AM (20 microM). In addition, an increase in the neurotoxic effect of Tat, which was assessed by trypan blue exclusion assay, was observed. The result led the authors to conclude that alcohol exposure significantly potentiates Tat-induced calcium overload and neuronal death. PMID:16595370

  15. Nrf2-ARE Activator Carnosic Acid Decreases Mitochondrial Dysfunction, Oxidative Damage and Neuronal Cytoskeletal Degradation Following Traumatic Brain Injury in Mice

    PubMed Central

    Miller, Darren M.; Singh, Indrapal N.; Wang, Juan A.; Hall, Edward D.

    2014-01-01

    The importance of free radical-induced oxidative damage after traumatic brain injury (TBI) has been well documented. Despite multiple clinical trials with radical-scavenging antioxidants that are neuroprotective in TBI models, none is approved for acute TBI patients. As an alternative antioxidant target, Nrf2 is a transcription factor that activates expression of antioxidant and cytoprotective genes by binding to antioxidant response elements (ARE) within DNA. Previous research has shown that neuronal mitochondria are susceptible to oxidative damage post-TBI, and thus the current study investigates whether Nrf2-ARE activation protects mitochondrial function when activated post-TBI. It was hypothesized that administration of carnosic acid (CA) would reduce oxidative damage biomarkers in brain tissue and also preserve cortical mitochondrial respiratory function post-TBI. A mouse controlled cortical impact (CCI) model was employed with a 1.0mm cortical deformation injury. Administration of CA at 15 minutes post-TBI reduced cortical lipid peroxidation, protein nitration, and cytoskeletal breakdown markers in a dose-dependent manner at 48 hours post-injury. Moreover, CA preserved mitochondrial respiratory function compared to vehicle animals. This was accompanied by decreased oxidative damage to mitochondrial proteins, suggesting the mechanistic connection of the two effects. Lastly, delaying the initial administration of CA up to 8 hours post-TBI was still capable of reducing cytoskeletal breakdown, thereby demonstrating a clinically relevant therapeutic window for this approach. This study demonstrates that pharmacological Nrf2-ARE induction is capable of neuroprotective efficacy when administered after TBI. PMID:25432068

  16. Nucleus accumbens neuronal activity correlates to the animal’s behavioral response to acute and chronic methylphenidate

    PubMed Central

    Claussen, Catherine M; Chong, Samuel L; Dafny, Nachum

    2014-01-01

    Acute and chronic Methylphenidate (MPD) exposure was recorded simultaneously for the rat’s locomotor activity and the nucleus accumbens (NAc) neuronal activity. The evaluation of the neuronal events was based on the animal’s behavior response to chronic MPD administration: 1) Animals exhibiting behavioral sensitization 2) Animals exhibiting behavioral tolerance. The experiment lasted for 10 days with four groups of animals; saline, 0.6, 2.5, and 10.0mg/kg MPD. For the main behavioral findings, about half of the animals exhibited behavioral sensitization or behavioral tolerance to 0.6, 2.5, and/or 10 mg/kg MPD respectively. Three hundred and forty one NAc neuronal units were evaluated. Approximately 80% of NAc units responded to 0.6, 2.5, and 10.0 mg/kg MPD. When the neuronal activity was analyzed based on the animals behavioral response to chronic MPD exposure, significant differences were seen between the neuronal populations responses recorded from animals that expressed behavioral sensitization when compared to the NAc neuronal responses recorded from animals exhibiting behavioral tolerance. Three types of neurophysiological sensitization and neurophysiological tolerance can be recognized following chronic MPD administration to the neuronal populations. Collectively, these findings show that the same dose of chronic MPD can elicit either behavioral tolerance or behavioral sensitization. Differential statistical analysis were used to verify our hypothesis that the neuronal activity recorded from animals exhibiting behavioral sensitization will respond differently to MPD compared to those animals exhibiting behavioral tolerance. Thus, suggesting that it is essential to record the animals behavior concomitantly with neuronal recordings. PMID:24534179

  17. αKlotho deficiency in acute kidney injury contributes to lung damage.

    PubMed

    Ravikumar, Priya; Li, Liping; Ye, Jianfeng; Shi, Mingjun; Taniguchi, Masatomo; Zhang, Jianning; Kuro-O, Makoto; Hu, Ming Chang; Moe, Orson W; Hsia, Connie C W

    2016-04-01

    αKlotho is a circulating protein that originates predominantly from the kidney and exerts cytoprotective effects in distant sites. We previously showed in rodents that the lung is particularly vulnerable to αKlotho deficiency. Because acute lung injury is a common and serious complication of acute kidney injury (AKI), we hypothesized that αKlotho deficiency in AKI contributes to lung injury. To test the hypothesis, we created AKI by renal artery ischemia-reperfusion in rats and observed the development of alveolar interstitial edema and increased pulmonary oxidative damage to DNA, protein, and lipids. Administration of αKlotho-containing conditioned media 6 h post-AKI did not alter plasma creatinine but improved recovery of endogenous αKlotho production 3 days post-AKI, reduced lung edema and oxidative damage, and increased endogenous antioxidative capacity in the lung. Intravenously injected αKlotho rapidly exits alveolar capillaries as a macromolecule, suggesting transcytosis and direct access to the epithelium. To explore the epithelial action of αKlotho, we simulated oxidative stress in vitro by adding hydrogen peroxide to cultured A549 lung epithelial cells. Purified recombinant αKlotho directly protected cells at 20 pM with half-maximal effects at 40-50 pM, which is compatible with circulating αKlotho levels. Addition of recombinant αKlotho activated an antioxidant response element reporter and increased the levels of target proteins of the nuclear factor erythroid-derived 2 related factor system. In summary, αKlotho deficiency in AKI contributes to acute lung injury by reducing endogenous antioxidative capacity and increasing oxidative damage in the lung. αKlotho replacement partially reversed these abnormalities and mitigated pulmonary complications in AKI. PMID:26718784

  18. Acute and chronic administration of gold nanoparticles cause DNA damage in the cerebral cortex of adult rats.

    PubMed

    Cardoso, Eria; Rezin, Gislaine Tezza; Zanoni, Elton Torres; de Souza Notoya, Frederico; Leffa, Daniela Dimer; Damiani, Adriani Paganini; Daumann, Francine; Rodriguez, Juan Carlos Ortiz; Benavides, Roberto; da Silva, Luciano; Andrade, Vanessa M; da Silva Paula, Marcos Marques

    2014-01-01

    The use of gold nanoparticles is increasing in medicine; however, their toxic effects remain to be elucidated. Studies show that gold nanoparticles can cross the blood-brain barrier, as well as accumulate in the brain. Therefore, this study was undertaken to better understand the effects of gold nanoparticles on rat brains. DNA damage parameters were evaluated in the cerebral cortex of adult rats submitted to acute and chronic administration of gold nanoparticles of two different diameters: 10 and 30nm. During acute administration, adult rats received a single intraperitoneal injection of either gold nanoparticles or saline solution. During chronic administration, adult rats received a daily single injection for 28 days of the same gold nanoparticles or saline solution. Twenty-four hours after either single (acute) or last injection (chronic), the rats were euthanized by decapitation, their brains removed, and the cerebral cortices isolated for evaluation of DNA damage parameters. Our study showed that acute administration of gold nanoparticles in adult rats presented higher levels of damage frequency and damage index in their DNA compared to the control group. It was also observed that gold nanoparticles of 30nm presented higher levels of damage frequency and damage index in the DNA compared to the 10nm ones. When comparing the effects of chronic administration of gold nanoparticles of 10 and 30nm, we observed that occurred significant different index and frequency damage, comparing with control group. However, there is no difference between the 10 and 30nm groups in the levels of DNA damage for both parameters of the Comet assay. Results suggest that gold nanoparticles for both sizes cause DNA damage for chronic as well as acute treatments, although a higher damage was observed for the chronic one. PMID:25847268

  19. [Pharmacological correction of toxic liver damage in patients with heavy forms of acute ethanol intoxication].

    PubMed

    Shikalova, I A; Shilov, V V; Vasil'ev, S A; Batotsyrenov, B V; Loladze, A T

    2012-01-01

    The efficiency of using remaxol and ademethionine in the therapy of patients with heavy acute alcohol intoxication on the background of toxic liver damage has been studied. The administration of remaxol led to improvement of the clinical treatment of alcohol intoxication, which is manifested by a decrease in the rate and duration of delirium tremens (from 33.9 to 10.8%), frequency of secondary lung disorders (from 18.5 to 3.1%), duration of stay in hospital (from 7.3 +/- 0.6 to 5.6 +/- 0.3 days), and total therapy duration (from 11.8 +/- 1.05 to 5.6 +/- 0.3 days). The results of biochemical investigations confirmed that remaxol and ademethionine provide effective treatment of the toxic liver damage. Remaxol decreases the degree of metabolic disorders to a greater extent than does ademethionine. PMID:22702109

  20. Chronic infection with Toxoplasma gondii induces death of submucosal enteric neurons and damage in the colonic mucosa of rats.

    PubMed

    Góis, Marcelo Biondaro; Hermes-Uliana, Catchia; Barreto Zago, Maísa Cristina; Zanoni, Jacqueline Nelisis; da Silva, Aristeu Vieira; de Miranda-Neto, Marcílio Hubner; Almeida Araújo, Eduardo José de; Sant'Ana, Débora de Mello Gonçales

    2016-05-01

    Intestinal epithelial secretion is coordinated by the submucosal plexus (SMP). Chemical mediators from SMP regulate the immunobiological response and direct actions against infectious agents. Toxoplasma gondii is a worldwide parasite that causes toxoplasmosis. This study aimed to determine the effects of chronic infection with T. gondii on the morphometry of the mucosa and the submucosal enteric neurons in the proximal colon of rats. Male adult rats were distributed into a control group (n = 10) and an infected group (n = 10). Infected rats received orally 500 oocysts of T. gondii (ME-49). After 36 days, the rats were euthanized and samples of the proximal colon were processed for histology to evaluate mucosal thickness in sections. Whole mounts were stained with methylene blue and subjected to immunohistochemistry to detect vasoactive intestinal polypeptide. The total number of submucosal neurons decreased by 16.20%. Vasoactive intestinal polypeptide-immunoreactive neurons increased by 26.95%. Intraepithelial lymphocytes increased by 62.86% and sulfomucin-producing goblet cells decreased by 22.87%. Crypt depth was greater by 43.02%. It was concluded that chronic infection with T. gondii induced death and hypertrophy in the remaining submucosal enteric neurons and damage to the colonic mucosa of rats. PMID:26902605

  1. Neuronal and inducible nitric oxide synthase upregulation in the rat medial prefrontal cortex following acute restraint stress: A dataset.

    PubMed

    Spiers, Jereme G; Chen, Hsiao-Jou Cortina; Lee, Johnny K; Sernia, Conrad; Lavidis, Nickolas A

    2016-03-01

    This data article provides additional evidence on gene expression changes in the neuronal and inducible isoforms of nitric oxide synthase in the medial prefrontal cortex following acute stress. Male Wistar rats aged 6-8 weeks were exposed to control or restraint stress conditions for up to four hours in the dark cycle after which the brain was removed and the medial prefrontal cortex isolated by cryodissection. Following RNA extraction and cDNA synthesis, gene expression data were measured using quantitative real-time PCR. The mRNA levels of the neuronal and inducible nitric oxide synthase isoforms, and the inhibitory subunit of NF-κB, I kappa B alpha were determined using the ΔΔCT method relative to control animals. This data article presents complementary results related to the research article entitled 'Acute restraint stress induces specific changes in nitric oxide production and inflammatory markers in the rat hippocampus and striatum' [1]. PMID:26909371

  2. Platelet microparticle number is associated with the extent of myocardial damage in acute myocardial infarction

    PubMed Central

    Puspitawati, Ira; Gharini, Putrika Prastuti Ratna; Setianto, Budi Yuli

    2016-01-01

    Introduction Activated platelets generate microparticles. Increased platelet microparticles occur in acute myocardial infarction (AMI) and contribute to intracoronary thrombosis and subsequent myocardial injury. This study aimed to investigate the impact of platelet microparticles on intracoronary thrombosis by assessing the relationship between platelet microparticles and the extent of myocardial damage in AMI. Material and methods This was a cross sectional study. The subjects were patients with acute coronary syndrome (ACS). Forty-one consecutive subjects with ACS admitted to intensive cardiovascular care unit were enrolled. The clinical spectrum of ACS comprised AMI (n = 26), both ST-elevation AMI (STEMI) and non-ST-elevation AMI (NSTEMI), and unstable angina (n = 15). Platelet microparticles were isolated from peripheral venous blood and detected with anti-CD42b-PE by the flow cytometry method. The extent of myocardial damage was determined by measuring the peak level of serial cardiac enzymes within 24 h of admission. Results Subjects with AMI had a significantly higher number of platelet microparticles than those with unstable angina (4855 ±4509/µl vs. 2181 ±1923/µl respectively; p = 0.036). Subjects with STEMI had the highest number of platelet microparticles, but no significant difference was detected as compared to those with NSTEMI (5775 ±5680/µl vs. 3601 ±1632/µl). The number of platelet microparticles in AMI was positively associated with the extent of myocardial damage (peak CK-MB: r = 0.408, p = 0.019 and peak GOT: r = 0.384, p = 0.026). Conclusions The number of platelet microparticles was increased in AMI as compared to unstable angina and associated with the extent of myocardial damage. PMID:27279844

  3. Radix Ilicis Pubescentis total flavonoids ameliorates neuronal damage and reduces lesion extent in a mouse model of transient ischemic attack

    PubMed Central

    Miao, Ming-san; Guo, Lin; Li, Rui-qi; Zhang, Xiao-lei

    2016-01-01

    Flavonoids are a major component in the traditional Chinese medicine Radix Ilicis Pubescentis. Previous studies have shown that the administration of Radix Ilicis Pubescentis total flavonoids is protective in cerebral ischemia. However, to our knowledge, no studies have examined whether the total flavonoids extracted from Radix Ilicis Pubescentis prevent or ameliorate neuronal damage following transient ischemic attacks. Therefore, Radix Ilicis Pubescentis total flavonoids question and the potential underlying mechanisms. Thus, beginning 3 days before the induction of a mouse model of transient ischemic attack using tert-butyl hydroperoxide injections, mice were intragastrically administered 0.3, 0.15, or 0.075 g/kg of Radix Ilicis Pubescentis total flavonoids daily for 10 days. The results of spectrophotometric analyses demonstrated that Radix Ilicis Pubescentis total flavonoids enhanced oxygen free radical scavenging and reduced pathological alterations in the brain. Hematoxylin-eosin staining results showed that Radix Ilicis Pubescentis total flavonoids reduced hippocampal neuronal damage and cerebral vascular injury in this mouse model of transient ischemic attack. These results suggest that the antioxidant effects of Radix Ilicis Pubescentis total flavonoids alleviate the damage to brain tissue caused by transient ischemic attack. PMID:27127483

  4. Detection of neuronal damage in degenerative brain disease with cobalt-55 and positron emission tomography

    SciTech Connect

    Jansen, H.M.L.; Pruim, J.; Paans, A.M.J.

    1994-05-01

    We suggest Cobalt-55 (Co) as a Calcium (Ca)-marker to visualize Ca transport across the neuronal membrane. Elevation of intracellular Ca is closely linked with the process of neuronal cell-decay. Co-uptake is correlated with Ca-accumulation through divalent cation-permeable kainate (KA)-activated receptor-operated channels in the neuronal membrane. This hypothesis was studied with position emission tomography (PET) both in patients with a ischemic cerebro-vascular accident (CVA) and in patients with relapsing progressive multiple sclerosis (MS). Co-PET studies were performed in a dynamic mode (6 frames of 10 minutes) 20-25 hours after iv.-administration of 1-2 mCi Co. Regional specific accumulation irrespective of blood brain barrier (BBB) integrity in the (clinically appropriate) affected cerebral region could be demonstrated in CVA-patients, thus suggesting neuronal decay in (the early phase of) infarction. In MS, inhomogeneous cerebral distribution of Co was detected, in contrast to healthy volunteers. This suggests focal accumulation of Co in multiple spots of neuronal decay, possibly related to MS-lesions on MRI. In conclusion, Co-PET may prove to be a valuable tool for the early detection of neuronal decay not only in CVA and MS, but in other brain-pathology as well. The usefulness of Co-PET in imaging brain-tumors and myocardial ischemia has already been established.

  5. Astrocytic Ca(2+) waves mediate activation of extrasynaptic NMDA receptors in hippocampal neurons to aggravate brain damage during ischemia.

    PubMed

    Dong, Qi-Ping; He, Jing-Quan; Chai, Zhen

    2013-10-01

    Excitotoxicity plays a central role in the neuronal damage during ischemic stroke. Although growing evidence suggests that activation of extrasynaptic NMDA receptors initiates neuronal death, no direct evidence demonstrated their activation during ischemia. Using rat hippocampal slices, we detected oxygen-glucose deprivation (OGD) induced slow inward currents (SICs) mediated by extrasynaptic NMDA receptors in CA1 pyramidal neurons. Moreover, Ca(2+) chelator BAPTA dialysis into astrocytic network decreased the frequency of OGD induced SICs, indicating that the activation of extrasynaptic NMDA receptors depended on astrocytic Ca(2+) activity. To further demonstrate the importance of astrocytic Ca(2+) activity, we tested hippocampal slices from inositol triphosphate receptor type 2 (IP3R2) knock-out mice which abolished the astrocytic Ca(2+) activity. As expected, the frequency of OGD induced SICs was reduced. Using two-photon Ca(2+) imaging, we characterized the astrocytic Ca(2+) dynamics. By controlling Ca(2+) level in the individual astrocytes using targeted photolysis, we found that OGD facilitated the propagation of intercellular Ca(2+) waves, which were inhibited by gap junction blocker carbenoxolone (CBX). CBX also inhibited the Ca(2+) activity of the astrocytic network and decreased the SIC frequency during OGD. Functionally, the infarct volumes from brain ischemia were reduced in IP3R2 knock-out mice and in rat intracerebrally delivered with CBX. Our results demonstrate that enhanced Ca(2+) activity of the astrocytic network plays a key role on the activation of extrasynaptic NMDA receptors in hippocampal neurons, which enhances brain damage during ischemia. PMID:23702310

  6. Eriocaulon buergerianum extract protects PC12 cells and neurons in zebrafish against 6-hydroxydopamine-induced damage

    PubMed Central

    2011-01-01

    Background Ericaulon buergerianum (Gujingcao) is an ophthalmic, anti-inflammatory and antimicrobial Chinese medicinal herb. This study aims to investigate the neuroprotective effects of Ericaulon buergerianum ethanol extract (EBE) and to elucidate its underlying action mechanism. Methods The viability of dopaminergic (DA) neuron in zebrafish was examined by anti-tyrosine hydroxylase (TH) immunostaining. The locomotor activity of zebrafish was assessed with a digital video tracking system. The viability and cellular damage of the PC12 cells were determined by MTT and LDH assays respectively. The nuclear morphological changes in apoptotic cells were evaluated with DNA staining by Hoechst 33342 dye. Intracellular nitric oxide (NO) was quantified by DAF-FM diacetate staining. The expression of inducible nitric oxide synthase (iNOS) was determined by Western blot. Results EBE inhibited the 6-OHDA-induced decrease in total distance of movement in zebrafish. Pretreatments of EBE (25, 50, 100 and 200 μg/ml) increased the viability of 6-OHDA-damaged PC12 cells in a dose dependent manner. Protection against 6-OHDA-induced nuclear fragmentation and accumulation of apoptotic bodies was also observed in EBE pretreated cells. Anti-oxidative (inhibition of NO production and iNOS expression in PC12 cells in vitro) activities of EBE are related to its neuroprotective effects in 6-OHDA-induced DA neuron damage. Conclusion EBE exhibited significant neuroprotective activities in zebrafish, including recovery of dopaminergic neuron loss caused by 6-OHDA in a dose-dependent manner in vivo, inhibition of 6-OHDA-induced decrease of total distance in movement in zebrafish. The iNOS-NO pathway may be involved. PMID:21527031

  7. Hyperthermic preconditioning severely accelerates neuronal damage in the gerbil ischemic hippocampal dentate gyrus via decreasing SODs expressions.

    PubMed

    Kim, Dong Won; Cho, Jeong-Hwi; Cho, Geum-Sil; Kim, In Hye; Park, Joon Ha; Ahn, Ji Hyeon; Chen, Bai Hui; Shin, Bich-Na; Tae, Hyun-Jin; Hong, Seongkweon; Cho, Jun Hwi; Kim, Young-Myeong; Won, Moo-Ho; Lee, Jae-Chul

    2015-11-15

    It is well known that neurons in the dentate gyrus (DG) of the hippocampus are resistant to short period of ischemia. Hyperthermia is a proven risk factor for cerebral ischemia and can produce more extensive brain damage related with mortality rates. The aim of this study was to examine the effect of hyperthermic conditioning (H) on neuronal death, gliosis and expressions of SODs as anti-oxidative enzymes in the gerbil DG following 5 min-transient cerebral ischemia. The animals were randomly assigned to 4 groups: 1) (N+sham)-group was given sham-operation with normothermia (N); 2) (N+ischemia)-group was given 5 min-transient ischemia with N; 3) (H+sham)-group was given sham-operation with H; and 4) (H+ischemia)-group was given 5 min-transient cerebral ischemia with H. H (39±0.5°C) was induced by subjecting the animals to a heating pad for 30 min before and during the operation. In the (N+ischemia)-groups, a significant neuronal death was observed in the polymorphic layer (PL) from 1 day after ischemia-reperfusion. In the (H+ischemia)-groups, neuronal death was also observed in the PL from 1day post-ischemia; the degree of the neuronal death was severer than that in the (N+ischemia)-groups. In addition, we examined the gliosis of astrocytes and microglia using anti-glial fibrillary acidic protein (GFAP) and anti- ionized calcium-binding adapter molecule 1 (Iba-1). GFAP(+) and Iba-1(+) glial cells were much more activated in the (H+ischemia)-groups than those in the (N+ischemia)-groups. On the other hand, immunoreactivities and levels of SOD1 rather than SOD2 were significantly lower in the (H+ischemia)-groups than those in the (N+ischemia)-groups. In brief, on the basis of our findings, we suggest that cerebral ischemic insult with hyperthermic conditioning brings up severer neuronal damage and gliosis in the polymorphic layer through reducing SOD1 expression rather than SOD2 expression in the DG. PMID:26365286

  8. Cutaneous tissue damage induces long-lasting nociceptive sensitization and regulation of cellular stress- and nerve injury-associated genes in sensory neurons.

    PubMed

    Rau, Kristofer K; Hill, Caitlin E; Harrison, Benjamin J; Venkat, Gayathri; Koenig, Heidi M; Cook, Sarah B; Rabchevsky, Alexander G; Taylor, Bradley K; Hai, Tsonwin; Petruska, Jeffrey C

    2016-09-01

    Tissue damage is one of the major etiological factors in the emergence of chronic/persistent pain, although mechanisms remain enigmatic. Using incision of the back skin of adult rats as a model for tissue damage, we observed sensitization in a nociceptive reflex enduring to 28days post-incision (DPI). To determine if the enduring behavioral changes corresponded with a long-term impact of tissue damage on sensory neurons, we examined the temporal expression profile of injury-regulated genes and the electrophysiological properties of traced dorsal root ganglion (DRG) sensory neurons. The mRNA for the injury/stress-hub gene Activating Transcription Factor 3 (ATF3) was upregulated and peaked within 4 DPI, after which levels declined but remained significantly elevated out to 28 DPI, a time when the initial incision appears healed and tissue-inflammation largely resolved. Accordingly, stereological image analysis indicated that some neurons expressed ATF3 only transiently (mostly medium-large neurons), while in others it was sustained (mostly small neurons), suggesting cell-type-specific responses. In retrogradely-traced ATF3-expressing neurons, Calcium/calmodulin-dependent protein kinase type IV (CAMK4) protein levels and isolectin-B4 (IB4)-binding were suppressed whereas Growth Associated Protein-43 (GAP-43) and Neuropeptide Y (NPY) protein levels were enhanced. Electrophysiological recordings from DiI-traced sensory neurons 28 DPI showed a significant sensitization limited to ATF3-expressing neurons. Thus, ATF3 expression is revealed as a strong predictor of single cells displaying enduring pain-related electrophysiological properties. The cellular injury/stress response induced in sensory neurons by tissue damage and indicated by ATF3 expression is positioned to contribute to pain which can occur after tissue damage. PMID:27264359

  9. DNA Damage Focus Analysis in Blood Samples of Minipigs Reveals Acute Partial Body Irradiation

    PubMed Central

    Lamkowski, Andreas; Forcheron, Fabien; Agay, Diane; Ahmed, Emad A.; Drouet, Michel; Meineke, Viktor; Scherthan, Harry

    2014-01-01

    Radiation accidents frequently involve acute high dose partial body irradiation leading to victims with radiation sickness and cutaneous radiation syndrome that implements radiation-induced cell death. Cells that are not lethally hit seek to repair ionizing radiation (IR) induced damage, albeit at the expense of an increased risk of mutation and tumor formation due to misrepair of IR-induced DNA double strand breaks (DSBs). The response to DNA damage includes phosphorylation of histone H2AX in the vicinity of DSBs, creating foci in the nucleus whose enumeration can serve as a radiation biodosimeter. Here, we investigated γH2AX and DNA repair foci in peripheral blood lymphocytes of Göttingen minipigs that experienced acute partial body irradiation (PBI) with 49 Gy (±6%) Co-60 γ-rays of the upper lumbar region. Blood samples taken 4, 24 and 168 hours post PBI were subjected to γ-H2AX, 53BP1 and MRE11 focus enumeration. Peripheral blood lymphocytes (PBL) of 49 Gy partial body irradiated minipigs were found to display 1–8 DNA damage foci/cell. These PBL values significantly deceed the high foci numbers observed in keratinocyte nuclei of the directly γ-irradiated minipig skin regions, indicating a limited resident time of PBL in the exposed tissue volume. Nonetheless, PBL samples obtained 4 h post IR in average contained 2.2% of cells displaying a pan-γH2AX signal, suggesting that these received a higher IR dose. Moreover, dispersion analysis indicated partial body irradiation for all 13 minipigs at 4 h post IR. While dose reconstruction using γH2AX DNA repair foci in lymphocytes after in vivo PBI represents a challenge, the DNA damage focus assay may serve as a rapid, first line indicator of radiation exposure. The occurrence of PBLs with pan-γH2AX staining and of cells with relatively high foci numbers that skew a Poisson distribution may be taken as indicator of acute high dose partial body irradiation, particularly when samples are available early after

  10. DNA damage focus analysis in blood samples of minipigs reveals acute partial body irradiation.

    PubMed

    Lamkowski, Andreas; Forcheron, Fabien; Agay, Diane; Ahmed, Emad A; Drouet, Michel; Meineke, Viktor; Scherthan, Harry

    2014-01-01

    Radiation accidents frequently involve acute high dose partial body irradiation leading to victims with radiation sickness and cutaneous radiation syndrome that implements radiation-induced cell death. Cells that are not lethally hit seek to repair ionizing radiation (IR) induced damage, albeit at the expense of an increased risk of mutation and tumor formation due to misrepair of IR-induced DNA double strand breaks (DSBs). The response to DNA damage includes phosphorylation of histone H2AX in the vicinity of DSBs, creating foci in the nucleus whose enumeration can serve as a radiation biodosimeter. Here, we investigated γH2AX and DNA repair foci in peripheral blood lymphocytes of Göttingen minipigs that experienced acute partial body irradiation (PBI) with 49 Gy (± 6%) Co-60 γ-rays of the upper lumbar region. Blood samples taken 4, 24 and 168 hours post PBI were subjected to γ-H2AX, 53BP1 and MRE11 focus enumeration. Peripheral blood lymphocytes (PBL) of 49 Gy partial body irradiated minipigs were found to display 1-8 DNA damage foci/cell. These PBL values significantly deceed the high foci numbers observed in keratinocyte nuclei of the directly γ-irradiated minipig skin regions, indicating a limited resident time of PBL in the exposed tissue volume. Nonetheless, PBL samples obtained 4 h post IR in average contained 2.2% of cells displaying a pan-γH2AX signal, suggesting that these received a higher IR dose. Moreover, dispersion analysis indicated partial body irradiation for all 13 minipigs at 4 h post IR. While dose reconstruction using γH2AX DNA repair foci in lymphocytes after in vivo PBI represents a challenge, the DNA damage focus assay may serve as a rapid, first line indicator of radiation exposure. The occurrence of PBLs with pan-γH2AX staining and of cells with relatively high foci numbers that skew a Poisson distribution may be taken as indicator of acute high dose partial body irradiation, particularly when samples are available early after IR

  11. Neuropathological characterization of spinal motor neuron degeneration processes induced by acute and chronic excitotoxic stimulus in vivo.

    PubMed

    Ramírez-Jarquín, Uri Nimrod; Tapia, Ricardo

    2016-09-01

    Motor neuron (MN) diseases are characterized by progressive cell degeneration, and excitotoxicity has been postulated as a causal factor. Using two experimental procedures for inducing excitotoxic spinal MN degeneration in vivo, by acute and chronic overactivation of α-amino-3-hydroxy-5-methyl-4-isoxazoleacetic acid (AMPA) receptors, we characterized the time course of the neuropathological changes. Electron transmission microscopy showed that acute AMPA perfusion by microdialysis caused MN swelling 1.5h after surgery and lysis with membrane rupture as early as 3h; no cleaved caspase 3 was detected by immunochemistry. Chronic AMPA infusion by osmotic minipumps induced a slow degeneration process along 5days, characterized by progressive changes: endoplasmic reticulum swelling, vacuolization of cytoplasm, vacuole fusion and cell membrane rupture. Quantification of these ultrastructural alterations showed that the increase of vacuolated area was at the expense of the nuclear area. Caspase 3 cleavage was observed since the first day of AMPA infusion. We conclude that acute AMPA-induced excitotoxicity induces MN loss by necrosis, while the progress of degeneration induced by chronic infusion is slow, starting with an early apoptotic process followed by necrosis. In both the acute and chronic procedures a correlation could be established between the loss of MN by necrosis, but not by caspase 3-linked apoptosis, and severe motor deficits and hindlimb paralysis. Our findings are relevant for understanding the mechanisms of neuron death in degenerative diseases and thus for the design of pharmacological therapeutic strategies. PMID:27320208

  12. Contrasting alterations to synaptic and intrinsic properties in upper-cervical superficial dorsal horn neurons following acute neck muscle inflammation

    PubMed Central

    2014-01-01

    Background Acute and chronic pain in axial structures, like the back and neck, are difficult to treat, and have incidence as high as 15%. Surprisingly, most preclinical work on pain mechanisms focuses on cutaneous structures in the limbs and animal models of axial pain are not widely available. Accordingly, we developed a mouse model of acute cervical muscle inflammation and assessed the functional properties of superficial dorsal horn (SDH) neurons. Results Male C57/Bl6 mice (P24-P40) were deeply anaesthetised (urethane 2.2 g/kg i.p) and the rectus capitis major muscle (RCM) injected with 40 μl of 2% carrageenan. Sham animals received vehicle injection and controls remained anaesthetised for 2 hrs. Mice in each group were sacrificed at 2 hrs for analysis. c-Fos staining was used to determine the location of activated neurons. c-Fos labelling in carrageenan-injected mice was concentrated within ipsilateral (87% and 63% of labelled neurons in C1 and C2 segments, respectively) and contralateral laminae I - II with some expression in lateral lamina V. c-Fos expression remained below detectable levels in control and sham animals. In additional experiments, whole cell recordings were obtained from visualised SDH neurons in transverse slices in the ipsilateral C1 and C2 spinal segments. Resting membrane potential and input resistance were not altered. Mean spontaneous EPSC amplitude was reduced by ~20% in neurons from carrageenan-injected mice versus control and sham animals (20.63 ± 1.05 vs. 24.64 ± 0.91 and 25.87 ± 1.32 pA, respectively). The amplitude (238 ± 33 vs. 494 ± 96 and 593 ± 167 pA) and inactivation time constant (12.9 ± 1.5 vs. 22.1 ± 3.6 and 15.3 ± 1.4 ms) of the rapid A type potassium current (IAr), the dominant subthreshold current in SDH neurons, were reduced in carrageenan-injected mice. Conclusions Excitatory synaptic drive onto, and important intrinsic properties (i.e., IAr) within SDH neurons are

  13. Acute crack cocaine exposure induces genetic damage in multiple organs of rats.

    PubMed

    Moretti, Eduardo Gregolin; Yujra, Veronica Quispe; Claudio, Samuel Rangel; Silva, Marcelo Jose Dias; Vilegas, Wagner; Pereira, Camilo Dias Seabra; de Oliveira, Flavia; Ribeiro, Daniel Araki

    2016-04-01

    Crack cocaine is a very toxic product derived from cocaine. The aim of this study was to evaluate genetic damage in multiple organs of rats following acute exposure to crack cocaine. A total of 20 Wistar rats were distributed into four groups (n = 5), as follows: 0, 4.5, 9, and 18 mg/kg body weight (b.w.) of crack cocaine administered by intraperitoneal route (i.p.). All animals were killed 24 h after intraperitoneal (i.p.) injection. The results showed that crack cocaine increased the number of micronucleated cells in bone marrow cells exposed to 18 mg/kg crack cocaine (p < 0.05). Peripheral blood and liver cells presented genetic damage as depicted by single cell gel (comet) assay at 9 and 18 mg/kg doses (p < 0.05). Immunohistochemistry data revealed significant increase in 8-hydroxy-20-deoxyguanosine (8-OHdG) immunoexpression in hepatocytes of animals exposed to crack cocaine at 9 and 18 mg/kg (p < 0.05) when compared with negative controls. Taken together, our results demonstrate that crack cocaine is able to induce genomic damage in multiple organs of Wistar rats. PMID:26825523

  14. Protective effect of diphenyl diselenide on acute liver damage induced by 2-nitropropane in rats.

    PubMed

    Borges, Lysandro P; Borges, Vanessa Corralo; Moro, Angelica Venturini; Nogueira, Cristina Wayne; Rocha, Joao Batista Teixeira; Zeni, Gilson

    2005-05-15

    The effect of diphenyl diselenide, (PhSe)2, administration on 2-nitropropane (2-NP)-induced hepatic damage was examined in male rats. Rats were pre-treated with a single dose of diphenyl diselenide (10, 50 or 100 micromol/kg). Afterward, they received only one dose of 2-NP (100 mg/kg body weight dissolved in olive oil). The parameters that indicate tissue damage such as plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), alpha-fetoprotein (AFP), creatinine and urea were determined. Since toxicity induced by 2-NP is related to oxidative stress, lipid peroxidation was also evaluated. Diphenyl diselenide (100 micromol/kg) significantly reduced plasma ALT, gamma-GGT, AFP levels when compared to 2-NP group. Treatment with diphenyl diselenide, at all doses, effectively protects the increase of lipid peroxidation when compared to 2-NP group. Histological examination revealed that 2-NP treatment causes a moderate swelling and degenerative alterations on hepatocytes and diphenyl diselenide (100 micromol/kg) protects against these alterations. Diphenyl diselenide (50 and 100 micromol/kg) significantly decreased the urea level. This study evidences the protective effect of diphenyl diselenide by 2-NP-induced acute hepatic damage. PMID:15804453

  15. Impaired Respiratory and Body Temperature Control Upon Acute Serotonergic Neuron Inhibition

    PubMed Central

    Ray, Russell; Corcoran, Andrea; Brust, Rachael; Kim, Jun Chul; Richerson, George B.; Nattie, Eugene; Dymecki, Susan M.

    2013-01-01

    Physiological homeostasis is essential for organism survival. Highly responsive neuronal networks are involved but constituent neurons are just beginning to be resolved. To query brain serotonergic neurons in homeostasis, we used a synthetic GPCR (Di)-based neuronal silencing tool, mouse RC∷FPDi, designed for cell type-specific, ligand (clozapine-N-oxide, CNO)-inducible and reversible suppression of action potential firing. In mice harboring Di-expressing serotonergic neurons, CNO administration by systemic injection attenuated the chemoreflex that normally increases respiration in response to tissue CO2 elevation and acidosis. At the cellular level, CNO suppressed firing rate increases evoked by CO2/acidosis. Body thermoregulation at room temperature was also disrupted following CNO triggering of Di; core temperatures plummeted, then recovered. This work establishes that serotonergic neurons regulate life-sustaining respiratory and thermoregulatory networks, and demonstrates a noninvasive tool for mapping neuron function. PMID:21798952

  16. α-Synuclein-induced synapse damage in cultured neurons is mediated by cholesterol-sensitive activation of cytoplasmic phospholipase A2.

    PubMed

    Bate, Clive; Williams, Alun

    2015-01-01

    The accumulation of aggregated forms of the α-synuclein (αSN) is associated with the pathogenesis of Parkinson's disease (PD) and Dementia with Lewy Bodies. The loss of synapses is an important event in the pathogenesis of these diseases. Here we show that aggregated recombinant human αSN, but not βSN, triggered synapse damage in cultured neurons as measured by the loss of synaptic proteins. Pre-treatment with the selective cytoplasmic phospholipase A2 (cPLA2) inhibitors AACOCF3 and MAFP protected neurons against αSN-induced synapse damage. Synapse damage was associated with the αSN-induced activation of synaptic cPLA2 and the production of prostaglandin E2. The activation of cPLA2 is the first step in the generation of platelet-activating factor (PAF) and PAF receptor antagonists (ginkgolide B or Hexa-PAF) also protect neurons against αSN-induced synapse damage. αSN-induced synapse damage was also reduced in neurons pre-treated with the cholesterol synthesis inhibitor (squalestatin). These results are consistent with the hypothesis that αSN triggered synapse damage via hyperactivation of cPLA2. They also indicate that αSN-induced activation of cPLA2 is influenced by the cholesterol content of membranes. Inhibitors of this pathway that can cross the blood brain barrier may protect against the synapse damage seen during PD. PMID:25761116

  17. Role of CCR5 and its ligands in the control of vascular inflammation and leukocyte recruitment required for acute excitotoxic seizure induction and neural damage

    PubMed Central

    Louboutin, Jean-Pierre; Chekmasova, Alena; Marusich, Elena; Agrawal, Lokesh; Strayer, David S.

    2011-01-01

    Chemokines may play a role in leukocyte migration across the blood-brain barrier (BBB) during neuroinflammation and other neuropathological processes, such as epilepsy. We investigated the role of the chemokine receptor CCR5 in seizures. We used a rat model based on intraperitoneal kainic acid (KA) administration. Four months before KA injection, adult rats were given femoral intramarrow inoculations of SV (RNAiR5-RevM10.AU1), which carries an interfering RNA (RNAi) against CCR5, plus a marker epitope (AU1), or its monofunctional RNAi-carrying homologue, SV(RNAiR5). This treatment lowered expression of CCR5 in circulating cells. In control rats, seizures induced elevated expression of CCR5 ligands MIP-1α and RANTES in the microvasculature, increased BBB leakage and CCR5+ cells, as well as neuronal loss, inflammation, and gliosis in the hippocampi. Animals given either the bifunctional or the monofunctional vector were largely protected from KA-induced seizures, neuroinflammation, BBB damage, and neuron loss. Brain CCR5 mRNA was reduced. Rats receiving RNAiR5-bearing vectors showed far greater repair responses: increased neuronal proliferation, and decreased production of MIP-1α and RANTES. Controls received unrelated SV(BUGT) vectors. Decrease in CCR5 in circulating cells strongly protected from excitotoxin-induced seizures, BBB leakage, CNS injury, and inflammation, and facilitated neurogenic repair.—Louboutin, J.-P., Chekmasova, A., Marusich, E., Agrawal, L., Strayer, D. S. Role of CCR5 and its ligands in the control of vascular inflammation and leukocyte recruitment required for acute excitotoxic seizure induction and neural damage. PMID:20940264

  18. Comparative cellular toxicity of titanium dioxide nanoparticles on human astrocyte and neuronal cells after acute and prolonged exposure.

    PubMed

    Coccini, Teresa; Grandi, Stefania; Lonati, Davide; Locatelli, Carlo; De Simone, Uliana

    2015-05-01

    Although in the last few decades, titanium dioxide nanoparticles (TiO₂NPs) have attracted extensive interest due to their use in wide range of applications, their influences on human health are still quite uncertain and less known. Evidence exists indicating TiO₂NPs ability to enter the brain, thus representing a realistic risk factor for both chronic and accidental exposure with the consequent needs for more detailed investigation on CNS. A rapid and effective in vitro test strategy has been applied to determine the effects of TiO₂NPs anatase isoform, on human glial (D384) and neuronal (SH-SY5Y) cell lines. Toxicity was assessed at different levels: mitochondrial function (by MTT), membrane integrity and cell morphology (by calcein AM/PI staining) after acute exposure (4-24-48 h) at doses from 1.5 to 250 μg/ml as well as growth and cell proliferation (by clonogenic test) after prolonged exposure (7-10 days) at sub-toxic concentrations (from 0.05 to 31 μg/ml). The cytotoxic effects of TiO₂NPs were compared with those caused by TiO₂ bulk counterpart treatment. Acute TiO₂NP exposure produced (i) dose- and time-dependent alterations of the mitochondrial function on D384 and SH-SY5Y cells starting at 31 and 15 μg/ml doses, respectively, after 24h exposure. SH-SY5Y were slightly more sensitive than D384 cells; and (ii) cell membrane damage occurring at 125 μg/ml after 24h exposure in both cerebral cells. Comparatively, the effects of TiO₂ bulk were less pronounced than those induced by nanoparticles in both cerebral cell lines. Prolonged exposure indicated that the proliferative capacity (colony size) was compromised at the extremely low TiO₂NP doses namely 1.5 μg/ml and 0.1 μg/ml for D384 and SH-SY5Y, respectively; cell sensitivity was still higher for SH-SY5Y compared to D384. Colony number decrease (15%) was also evidenced at ≥0.2 μg/ml TiO₂NP dose. Whereas, TiO₂ bulk treatment affected cell morphology only. TiO₂ internalization in SH

  19. Neuroprotective Effects of Inhibiting Fyn S-Nitrosylation on Cerebral Ischemia/Reperfusion-Induced Damage to CA1 Hippocampal Neurons

    PubMed Central

    Hao, Lingyun; Wei, Xuewen; Guo, Peng; Zhang, Guangyi; Qi, Suhua

    2016-01-01

    Nitric oxide (NO) can regulate signaling pathways via S-nitrosylation. Fyn can be post-translationally modified in many biological processes. In the present study, using a rat four-vessel-occlusion ischemic model, we aimed to assess whether Fyn could be S-nitrosylated and to evaluate the effects of Fyn S-nitrosylation on brain damage. In vitro, Fyn could be S-nitrosylated by S-nitrosoglutathione (GSNO, an exogenous NO donor), and in vivo, endogenous NO synthesized by NO synthases (NOS) could enhance Fyn S-nitrosylation. Application of GSNO, 7-nitroindazole (7-NI, an inhibitor of neuronal NOS) and hydrogen maleate (MK-801, the N-methyl-d-aspartate receptor (NMDAR) antagonist) could decrease the S-nitrosylation and phosphorylation of Fyn induced by cerebral ischemia/reperfusion (I/R). Cresyl violet staining validated that these compounds exerted neuroprotective effects against the cerebral I/R-induced damage to hippocampal CA1 neurons. Taken together, in this study, we demonstrated that Fyn can be S-nitrosylated both in vitro and in vivo and that inhibiting S-nitrosylation can exert neuroprotective effects against cerebral I/R injury, potentially via NMDAR-mediated mechanisms. These findings may lead to a new field of inquiry to investigate the underlying pathogenesis of stroke and the development of novel treatment strategies. PMID:27420046

  20. A reversible early oxidized redox state that precedes macromolecular ROS damage in aging nontransgenic and 3xTg-AD mouse neurons.

    PubMed

    Ghosh, Debolina; LeVault, Kelsey R; Barnett, Aaron J; Brewer, Gregory J

    2012-04-25

    The brain depends on redox electrons from nicotinamide adenine dinucleotide (reduced form; NADH) to produce ATP and oxyradicals (reactive oxygen species [ROS]). Because ROS damage and mitochondrial dysregulation are prominent in aging and Alzheimer's disease (AD) and their relationship to the redox state is unclear, we wanted to know whether an oxidative redox shift precedes these markers and leads to macromolecular damage in a mouse model of AD. We used the 3xTg-AD mouse model, which displays cognitive deficits beginning at 4 months. Hippocampal/cortical neurons were isolated across the age span and cultured in common nutrients to control for possible hormonal and vascular differences. We found an increase of NAD(P)H levels and redox state in nontransgenic (non-Tg) neurons until middle age, followed by a decline in old age. The 3xTg-AD neurons maintained much lower resting NAD(P)H and redox states after 4 months, but the NADH regenerating capacity continuously declined with age beginning at 2 months. These redox characteristics were partially reversible with nicotinamide, a biosynthetic precursor of NAD+. Nicotinamide also protected against glutamate excitotoxicity. Compared with non-Tg neurons, 3xTg-AD neurons had more mitochondria/neuron and lower glutathione (GSH) levels that preceded age-related increases in ROS levels. These GSH deficits were again reversible with nicotinamide in 3xTg-AD neurons. Surprisingly, low macromolecular ROS damage was only elevated after 4 months in the 3xTg-AD neurons if antioxidants were removed. The present data suggest that a more oxidized redox state and a lower antioxidant GSH defense can be dissociated from neuronal ROS damage, changes that precede the onset of cognitive deficits in the 3xTg-AD model. PMID:22539844

  1. Low Doses of Oxygen Ion Irradiation Cause Acute Damage to Hematopoietic Cells in Mice.

    PubMed

    Chang, Jianhui; Luo, Yi; Wang, Yingying; Pathak, Rupak; Sridharan, Vijayalakshmi; Jones, Tamako; Mao, Xiao Wen; Nelson, Gregory; Boerma, Marjan; Hauer-Jensen, Martin; Zhou, Daohong; Shao, Lijian

    2016-01-01

    One of the major health risks to astronauts is radiation on long-duration space missions. Space radiation from sun and galactic cosmic rays consists primarily of 85% protons, 14% helium nuclei and 1% high-energy high-charge (HZE) particles, such as oxygen (16O), carbon, silicon, and iron ions. HZE particles exhibit dense linear tracks of ionization associated with clustered DNA damage and often high relative biological effectiveness (RBE). Therefore, new knowledge of risks from HZE particle exposures must be obtained. In the present study, we investigated the acute effects of low doses of 16O irradiation on the hematopoietic system. Specifically, we exposed C57BL/6J mice to 0.1, 0.25 and 1.0 Gy whole body 16O (600 MeV/n) irradiation and examined the effects on peripheral blood (PB) cells, and bone marrow (BM) hematopoietic stem cells (HSCs) and hematopoietic progenitor cells (HPCs) at two weeks after the exposure. The results showed that the numbers of white blood cells, lymphocytes, monocytes, neutrophils and platelets were significantly decreased in PB after exposure to 1.0 Gy, but not to 0.1 or 0.25 Gy. However, both the frequency and number of HPCs and HSCs were reduced in a radiation dose-dependent manner in comparison to un-irradiated controls. Furthermore, HPCs and HSCs from irradiated mice exhibited a significant reduction in clonogenic function determined by the colony-forming and cobblestone area-forming cell assays. These acute adverse effects of 16O irradiation on HSCs coincided with an increased production of reactive oxygen species (ROS), enhanced cell cycle entry of quiescent HSCs, and increased DNA damage. However, none of the 16O exposures induced apoptosis in HSCs. These data suggest that exposure to low doses of 16O irradiation induces acute BM injury in a dose-dependent manner primarily via increasing ROS production, cell cycling, and DNA damage in HSCs. This finding may aid in developing novel strategies in the protection of the hematopoietic

  2. Low Doses of Oxygen Ion Irradiation Cause Acute Damage to Hematopoietic Cells in Mice

    PubMed Central

    Wang, Yingying; Pathak, Rupak; Sridharan, Vijayalakshmi; Jones, Tamako; Mao, Xiao Wen; Nelson, Gregory; Boerma, Marjan; Hauer-Jensen, Martin; Zhou, Daohong; Shao, Lijian

    2016-01-01

    One of the major health risks to astronauts is radiation on long-duration space missions. Space radiation from sun and galactic cosmic rays consists primarily of 85% protons, 14% helium nuclei and 1% high-energy high-charge (HZE) particles, such as oxygen (16O), carbon, silicon, and iron ions. HZE particles exhibit dense linear tracks of ionization associated with clustered DNA damage and often high relative biological effectiveness (RBE). Therefore, new knowledge of risks from HZE particle exposures must be obtained. In the present study, we investigated the acute effects of low doses of 16O irradiation on the hematopoietic system. Specifically, we exposed C57BL/6J mice to 0.1, 0.25 and 1.0 Gy whole body 16O (600 MeV/n) irradiation and examined the effects on peripheral blood (PB) cells, and bone marrow (BM) hematopoietic stem cells (HSCs) and hematopoietic progenitor cells (HPCs) at two weeks after the exposure. The results showed that the numbers of white blood cells, lymphocytes, monocytes, neutrophils and platelets were significantly decreased in PB after exposure to 1.0 Gy, but not to 0.1 or 0.25 Gy. However, both the frequency and number of HPCs and HSCs were reduced in a radiation dose-dependent manner in comparison to un-irradiated controls. Furthermore, HPCs and HSCs from irradiated mice exhibited a significant reduction in clonogenic function determined by the colony-forming and cobblestone area-forming cell assays. These acute adverse effects of 16O irradiation on HSCs coincided with an increased production of reactive oxygen species (ROS), enhanced cell cycle entry of quiescent HSCs, and increased DNA damage. However, none of the 16O exposures induced apoptosis in HSCs. These data suggest that exposure to low doses of 16O irradiation induces acute BM injury in a dose-dependent manner primarily via increasing ROS production, cell cycling, and DNA damage in HSCs. This finding may aid in developing novel strategies in the protection of the hematopoietic

  3. Propagation of Neuronal Damage to Embryonic Grafts Transplanted in the Hippocampus of Murine Models of Alzheimer's Disease.

    PubMed

    Sadallah, Mohcene; Labat-Gest, Vivien; Tempia, Filippo

    2015-12-01

    Alzheimer's disease (AD) is the most common form of dementia, characterized by the presence of two principal hallmarks-amyloid plaques and neurofibrillary tangles. The primary cause of the majority of AD cases is not known. Likewise, the mechanisms underlying the propagation of the pathology from affected tissue to neighboring healthy neurons are largely unknown, but knowledge about them could be helpful to design strategies aimed at halting the progression of the disease. To throw light on the mechanisms of propagation of neuronal damage to healthy tissue, wild-type (WT) hippocampal solid tissue chunks derived from green fluorescent protein (GFP)-positive embryos were grafted into the hippocampus of 6-month-old WT and 3xTg-AD mice, a triple-transgenic mouse model that exhibits both amyloid-beta (Aβ) and tau protein pathology. The histological and morphological alterations of the grafted tissues were assessed 3 months post-transplantation. Tissues grafted in 3xTg-AD hosts, compared to those grafted in WT recipients, presented a significant decrease in neurite outgrowth (35.4%) and dendritic spine density (41.3%), mainly due to a reduction of stubby and thin-shaped spines. Moreover, some cells of the tissue transplanted in 3xTg-AD hosts accumulated intracellular amyloid peptide deposits similar to the cells of the host. Furthermore, the immunohistochemical examination of reactive astrocytes and microglia revealed the presence of more inflammation in the grafted tissues hosted in 3xTg-AD compared to WT recipients. These results show a propagation of neuronal damage to initially healthy embryonic grafts, validating this methodology for future studies on the mechanisms of the progression of AD pathology to surrounding regions. PMID:26540615

  4. Cortical activity evoked by an acute painful tissue-damaging stimulus in healthy adult volunteers

    PubMed Central

    Williams, Gemma; Lee, Amy; Meek, Judith; Slater, Rebeccah; Olhede, Sofia; Fitzgerald, Maria

    2013-01-01

    Everyday painful experiences are usually single events accompanied by tissue damage, and yet most experimental studies of cutaneous nociceptive processing in the brain use repeated laser, thermal, or electrical stimulations that do not damage the skin. In this study the nociceptive activity in the brain evoked by tissue-damaging skin lance was analyzed with electroencephalography (EEG) in 20 healthy adult volunteers (13 men and 7 women) aged 21–40 yr. Time-frequency analysis of the evoked activity revealed a distinct late event-related vertex potential (lance event-related potential, LERP) at 100–300 ms consisting of a phase-locked energy increase between 1 and 20 Hz (delta-beta bands). A pairwise comparison between lance and sham control stimulation also revealed a period of ultralate stronger desynchronization after lance in the delta band (1–5 Hz). Skin application of mustard oil before lancing, which sensitizes a subpopulation of nociceptors expressing the cation channel TRPA1, did not affect the ultralate desynchronization but reduced the phase-locked energy increase in delta and beta bands, suggesting a central interaction between different modalities of nociceptive inputs. Verbal descriptor screening of individual pain experience revealed that lance pain is predominantly due to Aδ fiber activation, but when individuals describe lances as C fiber mediated, an ultralate delta band event-related desynchronization occurs in the brain-evoked activity. We conclude that pain evoked by acute tissue damage is associated with distinct Aδ and C fiber-mediated patterns of synchronization and desynchronization of EEG oscillations in the brain. PMID:23427303

  5. Ultrastructure damage of oviduct telocytes in rat model of acute salpingitis

    PubMed Central

    Yang, Jian; Chi, Chi; Liu, Zhen; Yang, Gang; Shen, Zong-Ji; Yang, Xiao-Jun

    2015-01-01

    Acute salpingitis (AS) is an inflammatory disease which causes severe damage to a subset of classically described cells lining in oviduct wall and contributes to interstitial fibrosis and fertility problems. Telocytes (TCs), a newly discovered peculiar type of stromal cells, have been identified in many organs, including oviduct, with proposed multiple potential bio-functions. However, with recent increasing reports regarding TCs alterations in disease-affected tissues, there is still lack of evidence about TCs involvement in AS-affected oviduct tissues and potential pathophysiological roles. We presently identified normal TCs by their characteristic ultrastructural features and immunophenotype. However, in AS-affected oviduct tissues, TCs displayed multiple ultrastructural damage both in cellular body and prolongations, with obvious loss of TCs and development of tissue fibrosis. Furthermore, TCs lose their interstitial 3-D network connected by homocellular or heterocellular junctions between TCs and adjacent cells. And especially, TCs connected to the activated immunocytes (mononuclear cells, eosinophils) and affected local immune state (repression or activation). Meanwhile, massive neutrophils infiltration and overproduced Inducible Nitric Oxide Synthase (iNOS), COX-2, suggested mechanism of inflammatory-induced TCs damage. Consequently, TCs damage might contribute to AS-induced structural and reproductive functional abnormalities of oviduct, probably via: (i) substances, energy and functional insufficiency, presumably, e.g. TC-specific genetic material profiles, ion channels, cytoskeletal elements, Tps dynamics, etc., (ii) impaired TCs-mediated multicellular signalling, such as homeostasis/angiogenesis, tissue repair/regeneration, neurotransmission, (iii) derangement of 3-D network and impaired mechanical support for TCs-mediated multicellular signals within the stromal compartment, consequently induced interstitial fibrosis, (iv) involvement in local

  6. Acute O3 damage on first year coppice sprouts of aspen and maple sprouts in an open-air experiment

    SciTech Connect

    Darbah, J.N.; Nagy, J.; Jones, W. S.; Burton, A. J.; Kubiske, M. E.

    2011-10-01

    We studied the effect of high ozone (O{sub 3}) concentration (110-490 nmol mol{sup -1}) on regenerating aspen (Populus tremuloides) and maple (Acer saccharum) trees at an open-air O{sub 3} pollution experiment near Rhinelander WI USA. This study is the first of its kind to examine the effects of acute O{sub 3} exposure on aspen and maple sprouts after the parent trees, which were grown under elevated O{sub 3} and/or CO{sub 2} for 12 years, were harvested. Acute O{sub 3} damage was not uniform within the crowns of aspen suckers; it was most severe in the mature, fully expanded photosynthesizing leaves. Young expanding leaves showed no visible signs of acute O{sub 3} damage contrary to expectations. Stomatal conductance played a primary role in the severity of acute O{sub 3} damage as it directly controlled O{sub 3} uptake. Maple sprouts, which had lower stomatal conductance, smaller stomatal aperture, higher stomatal density and larger leaf surface area, were tolerant of acute O{sub 3} exposure. Moreover, elevated CO{sub 2} did not ameliorate the adverse effects of acute O{sub 3} dose on aspen and maple sprouts, in contrast to its ability to counteract the effects of long-term chronic exposure to lower O{sub 3} levels.

  7. The endocannabinoid N-arachidonoyldopamine (NADA) exerts neuroprotective effects after excitotoxic neuronal damage via cannabinoid receptor 1 (CB(1)).

    PubMed

    Grabiec, Urszula; Koch, Marco; Kallendrusch, Sonja; Kraft, Robert; Hill, Kerstin; Merkwitz, Claudia; Ghadban, Chalid; Lutz, Beat; Straiker, Alex; Dehghani, Faramarz

    2012-03-01

    Endocannabinoids exert numerous effects in the CNS under physiological and pathological conditions. The aim of the present study was to examine whether the endocannabinoid N-arachidonoyldopamine (NADA) may protect neurons in excitotoxically lesioned organotypic hippocampal slice cultures (OHSC). OHSC were excitotoxically lesioned by application of N-methyl-d-aspartate (NMDA, 50 μM) for 4 h and subsequently treated with different NADA concentrations (0.1 pM-50 μM) alone or in combination with cannabinoid receptor antagonists. NADA protected dentate gyrus granule cells and caused a slight reduction in the number of microglial cells. The number of degenerated neurons significantly decreased between 100 pM and 10 μM NADA (p < 0.05). To identify the responsive receptor type of NADA mediated neuroprotection, we applied the cannabinoid (CB) receptor 1 (CB(1)) inverse agonist/antagonist AM251, CB(2) inverse agonist/antagonist AM630, abnormal-cannabidiol (abn-CBD)-sensitive receptor antagonist O-1918, transient receptor potential channel V1 (TRPV1) antagonist 6-iodonordihydrocapsaicin and A1 (TRPA1) antagonist HC-030031. Neuroprotective properties of low (1 nM) but not high (10 μM) NADA concentrations were solely blocked by AM251 and were absent in CB(1)(-/-) mice. AM630, O-1918, 6-iodonordihydrocapsaicin and HC-030031 showed no effects at all NADA concentrations applied. Our findings demonstrate that NADA protects dentate gyrus granule cells by acting via CB(1). NADA reduced the number of microglial cells at distinct concentrations. TRPV1 and TRPA1 were not involved in NADA mediated neuroprotection. Thus, our data implicate that NADA mediated activation of neuronal CB(1) may serve as a novel pharmacological target to mitigate symptoms of neuronal damage. PMID:22186081

  8. AMBIENT PARTICULATE MATTER STIMULATES OXIDATIVE STRESS IN BRAIN MICROGLIA AND DAMAGES NEURONS IN CULTURE.

    EPA Science Inventory

    Ambient particulate matter (PM) damages biological targets through oxidative stress (OS) pathways. Several reports indicate that the brain is one of those targets. Since microglia (brain macrophage) are critical to OS-mediated neurodegeneration, their response to concentrated amb...

  9. Neuroprotective properties of a protein kinase inhibitor against ischaemia-induced neuronal damage in rats and gerbils.

    PubMed Central

    Satoh, S.; Ikegaki, I.; Suzuki, Y.; Asano, T.; Shibuya, M.; Hidaka, H.

    1996-01-01

    1. The neuroprotective properties of fasudil (HA1077), a novel protein kinase inhibitor, were evaluated in two animal models of cerebral ischaemia: transient bilateral carotid artery occlusion in Mongolian gerbils and cerebral microembolization in rats. 2. The cytoprotective effect of fasudil on delayed neuronal death in gerbils was compared with the effects of nimodipine, a calcium channel antagonist and ozagrel, a thromboxane A2 synthetase inhibitor. The average of the neuronal cell density in the ischaemic control group was 17.8 +/- 2.1 cells mm-1, whereas fasudil (30 mg kg-1) significantly diminished the loss of CA1 neurones with the average of the neuronal cell density of 101.0 +/- 22.0 cells mm-1; nimodipine (10 mg kg-1) and ozagrel (30 mg kg-1) did not significantly protect against the ischaemia-induced neuronal loss. 3. In the rat model, the effects of fasudil on the histological and neurological consequences of cerebral microembolization produced via the injection of microspheres were examined. Twenty-four hours after the injection of microspheres into the internal carotid artery, all animals in the control group showed typical symptoms of stroke. Neurological function was significantly improved in the fasudil-treated animals. In the controls, the infarcted area in a cortical slice selected to include the hippocampal area was 0.25 +/- 0.01 cm2 (mean +/- s.e.mean) (43.9 +/- 2.4% of cortical section of the half hemisphere); the difference was significant compared to the mean area of 32.7 +/- 2.8 and 21.5 +/- 4.8% observed in rats treated with fasudil (3, 10 mg kg-1), respectively. Fasudil (10 mg kg-1) significantly suppressed the increased water content in ischaemic brain tissues (saline-treated rats, 82.4 +/- 0.2% vs fasudil-treated rats, 81.0 +/- 0.4%). 4. These results suggest that: (i) various protein kinases are involved in the pathogenesis of ischaemic injury; and (ii) the inhibition of protein kinases may be efficacious in preventing neuronal death

  10. Morphofunctional alterations in ventral tegmental area dopamine neurons in acute and prolonged opiates withdrawal. A computational perspective.

    PubMed

    Enrico, P; Migliore, M; Spiga, S; Mulas, G; Caboni, F; Diana, M

    2016-05-13

    Dopamine (DA) neurons of the ventral tegmental area (VTA) play a key role in the neurobiological basis of goal-directed behaviors and addiction. Morphine (MOR) withdrawal induces acute and long-term changes in the morphology and physiology of VTA DA cells, but the mechanisms underlying these modifications are poorly understood. Because of their predictive value, computational models are a powerful tool in neurobiological research, and are often used to gain further insights and deeper understanding on the molecular and physiological mechanisms underlying the development of various psychiatric disorders. Here we present a biophysical model of a DA VTA neuron based on 3D morphological reconstruction and electrophysiological data, showing how opiates withdrawal-driven morphological and electrophysiological changes could affect the firing rate and discharge pattern. The model findings suggest how and to what extent a change in the balance of GABA/GLU inputs can take into account the experimentally observed hypofunction of VTA DA neurons during acute and prolonged withdrawal, whereas morphological changes may play a role in the increased excitability of VTA DA cell to opiate administration observed during opiate withdrawal. PMID:26899424

  11. Inhibition of the group I mGluRs reduces acute brain damage and improves long-term histological outcomes after photothrombosis-induced ischaemia

    PubMed Central

    Li, Hailong; Zhang, Nannan; Sun, Grace; Ding, Shinghua

    2013-01-01

    Group I mGluRs (metabotropic glutamate receptors), including mGluR1 and mGluR5, are GPCRs (G-protein coupled receptors) and play important roles in physiology and pathology. Studies on their role in cerebral ischaemia have provided controversial results. In this study, we used a PT (photothrombosis)-induced ischaemia model to investigate whether antagonists to the group I mGluRs may offer acute and long-term protective effects in adult mice. Our results demonstrated that administration with mGluR5 antagonist MPEP [2-methyl-6-(phenylethynyl)-pyridine] or mGluR1 antagonist LY367385 by intraperitoneal injection at 3 h after PT decreased brain infarct volume evaluated one day after ischaemia. Additive effects on infarct volume were observed upon co-injection with MPEP and LY367385. These antagonists also significantly alleviated neurodegeneration and apoptosis in the penumbra. In addition, when evaluated 2 weeks after PT, they reduced infarct volume and tissue loss, attenuated glial scar formation, and inhibited cell proliferation in the penumbra. Importantly, co-injection with MPEP and LY367385 reduced the expression levels of calpain, a Ca2+-activated protease known to mediate ischaemia-induced neuronal death. Injection of calpeptin, a calpain inhibitor, could inhibit neuronal death and brain damage after PT but injection of calpeptin together with MPEP and LY367385 did not further improve the protective effects mediated by MPEP and LY367385. These results suggest that inhibition of group I mGluRs is sufficient to protect ischaemic damage through the calpain pathway. Taken together, our results demonstrate that inhibition of group I mGluRs can mitigate PT-induced brain damage through attenuating the effects of calpain, and improve long-term histological outcomes. PMID:23772679

  12. Arterial damages in acute elbow dislocations: which diagnostic tests are required?

    PubMed

    Lutter, Christoph; Pfefferkorn, Ronny; Schoeffl, Volker

    2016-01-01

    Blunt vessel injuries of peripheral arteries caused by a direct trauma are rare. Studies have described the frequency of arterial ruptures following closed elbow dislocations in 0.3-1.7% of all cases. However, arterial damage does not always necessarily appear as a complete rupture of the vessel with a loss of peripheral circulation and ischaemic symptoms; a relatively strong periarticular system of collaterals can maintain circulation. Furthermore, the traumatic dislocation can also cause intimal tears, arterial dissections and aneurysms or thrombosis. In all cases of vessel injury, including total disruption, a peripheral pulse might still be palpable. 3 weeks after an acute elbow dislocation, we have diagnosed a patient with a long-segment stenosis of the brachial artery and a thrombosis of the radial artery. Therefore, the close anatomic proximity to the neurovascular structures should always be considered in cases of elbow dislocations, even if peripheral pulses are traceable. PMID:27436035

  13. Acute MUS81 depletion leads to replication fork slowing and a constitutive DNA damage response

    PubMed Central

    Xing, Meichun; Wang, Xiaohui; Palmai-Pallag, Timea; Shen, Huahao; Helleday, Thomas; Hickson, Ian D.; Ying, Songmin

    2015-01-01

    The MUS81 protein belongs to a conserved family of DNA structure-specific nucleases that play important roles in DNA replication and repair. Inactivation of the Mus81 gene in mice has no major deleterious consequences for embryonic development, although cancer susceptibility has been reported. We have investigated the role of MUS81 in human cells by acutely depleting the protein using shRNAs. We found that MUS81 depletion from human fibroblasts leads to accumulation of ssDNA and a constitutive DNA damage response that ultimately activates cellular senescence. Moreover, we show that MUS81 is required for efficient replication fork progression during an unperturbed S-phase, and for recovery of productive replication following replication stalling. These results demonstrate essential roles for the MUS81 nuclease in maintenance of replication fork integrity. PMID:26415217

  14. Genotoxic evaluation of Mikania laevigata extract on DNA damage caused by acute coal dust exposure.

    PubMed

    Freitas, Tiago P; Heuser, Vanina D; Tavares, Priscila; Leffa, Daniela D; da Silva, Gabriela A; Citadini-Zanette, Vanilde; Romão, Pedro R T; Pinho, Ricardo A; Streck, Emilio L; Andrade, Vanessa M

    2009-06-01

    In the present article, we report data on the possible antigenotoxic activity of Mikania laevigata extract (MLE) after acute intratracheal instillation of coal dust using the comet assay in peripheral blood, bone marrow, and liver cells and the micronucleus test in peripheral blood of Wistar rats. The animals were pretreated for 2 weeks with saline solution (groups 1 and 2) or MLE (100 mg/kg) (groups 3 and 4). On day 15, the animals were anesthetized with ketamine (80 mg/kg) and xylazine (20 mg/kg), and gross mineral coal dust (3 mg/0.3 mL saline) (groups 2 and 4) or saline solution (0.3 mL) (groups 1 and 3) was administered directly in the lung by intratracheal administration. Fifteen days after coal dust or saline instillation, the animals were sacrificed, and the femur, liver, and peripheral blood were removed. The results showed a general increase in the DNA damage values at 8 hours for all treatment groups, probably related to surgical procedures that had stressed the animals. Also, liver cells from rats treated with coal dust, pretreated or not with MLE, showed statistically higher comet assay values compared to the control group at 14 days after exposure. These results could be expected because the liver metabolizes a variety of organic compounds to more polar by-products. On the other hand, the micronucleus assay results did not show significant differences among groups. Therefore, our data do not support the antimutagenic activity of M. laevigata as a modulator of DNA damage after acute coal dust instillation. PMID:19627217

  15. Selective Cyclooxygenase-2 Inhibition Protects Against Myocardial Damage in Experimental Acute Ischemia

    PubMed Central

    Carnieto, Alberto; Dourado, Paulo Magno Martins; da Luz, Protásio Lemos; Chagas, Antonio Carlos Palandri

    2009-01-01

    BACKGROUND Acute myocardial infarction is associated with tissue inflammation. Early coronary reperfusion clearly improves the outcome but may help propagate the inflammatory response and enhance tissue damage. Cyclooxygenase-2 is an enzyme that catalyzes the initial step in the formation of inflammatory prostaglandins from arachidonic acid. Cyclooxygenase-2 levels are increased when ischemic cardiac events occur. The overall function of COX-2 in the inflammatory process generated by myocardial ischemic damage has not yet been elucidated. GOAL The objective of this study was to determine whether a selective cyclooxygenase-2 inhibitor (rofecoxib) could alter the evolution of acute myocardial infarction after reperfusion. METHODS AND RESULTS This study was performed with 48 mongrel dogs divided into two groups: controls and those treated with the drug. All animals were prepared for left anterior descending coronary artery occlusion. The dogs then underwent 180 minutes of coronary occlusion, followed by 30 minutes of reperfusion. Blood samples were collected from the venous sinus immediately before coronary occlusion and after 30 minutes of reperfusion for measurements of CPK-MB, CPK-MBm and troponin I. During the experiment we observed the mean blood pressure, heart rate and coronary flow. The coronary flow and heart rate did not change, but in the control group, there was blood pressure instability, in addition to maximal levels of CPK-MB post-infarction. The same results were observed for CPK-MBm and troponin I. CONCLUSION In a canine model of myocardial ischemia-reperfusion, selective inhibition of Cyclooxygenase-2 with rofecoxib was not associated with early detrimental effects on the hemodynamic profile or the gross extent of infarction; in fact, it may be beneficial by limiting cell necrosis. PMID:19330252

  16. Genotoxic Evaluation of Mikania laevigata Extract on DNA Damage Caused by Acute Coal Dust Exposure

    SciTech Connect

    Freitas, T.P.; Heuser, V.D.; Tavares, P.; Leffa, D.D.; da Silva, G.A.; Citadini-Zanette, V.; Romao, P.R.T.; Pinho, R.A.; Streck, E.L.; Andrade,V.M.

    2009-06-15

    We report data on the possible antigenotoxic activity of Mikania laevigata extract (MLE) after acute intratracheal instillation of coal dust using the comet assay in peripheral blood, bone marrow, and liver cells and the micronucleus test in peripheral blood of Wistar rats. The animals were pretreated for 2 weeks with saline solution (groups 1 and 2) or MLE (100 mg/kg) (groups 3 and 4). On day 15, the animals were anesthetized with ketamine (80 mg/kg) and xylazine (20 mg/kg), and gross mineral coal dust (3 mg/0.3 mL saline) (groups 2 and 4) or saline solution (0.3 mL) (groups 1 and 3) was administered directly in the lung by intratracheal administration. Fifteen days after coal dust or saline instillation, the animals were sacrificed, and the femur, liver, and peripheral blood were removed. The results showed a general increase in the DNA damage values at 8 hours for all treatment groups, probably related to surgical procedures that had stressed the animals. Also, liver cells from rats treated with coal dust, pretreated or not with MLE, showed statistically higher comet assay values compared to the control group at 14 days after exposure. These results could be expected because the liver metabolizes a variety of organic compounds to more polar by-products. On the other hand, the micronucleus assay results did not show significant differences among groups. Therefore, our data do not support the antimutagenic activity of M. laevigata as a modulator of DNA damage after acute coal dust instillation.

  17. The effects of acute alcohol exposure on the response properties of neurons in visual cortex area 17 of cats

    SciTech Connect

    Chen Bo; Xia Jing; Li Guangxing; Zhou Yifeng

    2010-03-15

    Physiological and behavioral studies have demonstrated that a number of visual functions such as visual acuity, contrast sensitivity, and motion perception can be impaired by acute alcohol exposure. The orientation- and direction-selective responses of cells in primary visual cortex are thought to participate in the perception of form and motion. To investigate how orientation selectivity and direction selectivity of neurons are influenced by acute alcohol exposure in vivo, we used the extracellular single-unit recording technique to examine the response properties of neurons in primary visual cortex (A17) of adult cats. We found that alcohol reduces spontaneous activity, visual evoked unit responses, the signal-to-noise ratio, and orientation selectivity of A17 cells. In addition, small but detectable changes in both the preferred orientation/direction and the bandwidth of the orientation tuning curve of strongly orientation-biased A17 cells were observed after acute alcohol administration. Our findings may provide physiological evidence for some alcohol-related deficits in visual function observed in behavioral studies.

  18. Calpains and neuronal damage in the ischemic brain: The swiss knife in synaptic injury.

    PubMed

    Curcio, Michele; Salazar, Ivan L; Mele, Miranda; Canzoniero, Lorella M T; Duarte, Carlos B

    2016-08-01

    The excessive extracellular accumulation of glutamate in the ischemic brain leads to an overactivation of glutamate receptors with consequent excitotoxic neuronal death. Neuronal demise is largely due to a sustained activation of NMDA receptors for glutamate, with a consequent increase in the intracellular Ca(2+) concentration and activation of calcium- dependent mechanisms. Calpains are a group of Ca(2+)-dependent proteases that truncate specific proteins, and some of the cleavage products remain in the cell, although with a distinct function. Numerous studies have shown pre- and post-synaptic effects of calpains on glutamatergic and GABAergic synapses, targeting membrane- associated proteins as well as intracellular proteins. The resulting changes in the presynaptic proteome alter neurotransmitter release, while the cleavage of postsynaptic proteins affects directly or indirectly the activity of neurotransmitter receptors and downstream mechanisms. These alterations also disturb the balance between excitatory and inhibitory neurotransmission in the brain, with an impact in neuronal demise. In this review we discuss the evidence pointing to a role for calpains in the dysregulation of excitatory and inhibitory synapses in brain ischemia, at the pre- and post-synaptic levels, as well as the functional consequences. Although targeting calpain-dependent mechanisms may constitute a good therapeutic approach for stroke, specific strategies should be developed to avoid non-specific effects given the important regulatory role played by these proteases under normal physiological conditions. PMID:27283248

  19. Synthesis of a Novel Photopolymerized Nanocomposite Hydrogel for Treatment of Acute Mechanical Damage to Cartilage

    PubMed Central

    Schlichting, Kathryn; Copeland-Johnson, Trishelle M.; Goodman, Matthew; Lipert, Robert J.; Prozorov, Tanya; Liu, Xunpei; McKinley, Todd O.; Lin, Zhiqun; Martin, James A.; Mallapragada, Surya K.

    2014-01-01

    Intraarticular fractures initiate a cascade of pathobiologic and pathomechanical events that culminate in posttraumatic osteoarthritis (PTOA). Hallmark features of PTOA include destruction of the cartilage matrix in combination with loss of chondrocytes and acute mechanical damage (AMD). Currently, treatment of intraarticular fractures essentially is completely focused on restoration of the macroanatomy of the joint. However, current treatment ignores AMD sustained by cartilage at the time of injury. We are exploring aggressive biomaterial-based interventions designed to treat the primary pathologic components of AMD. This study describes the development of a novel injectable copolymer solution that forms gels at physiological temperatures that can be photocrosslinked, and can form nanocomposite gels insitu through mineralization. The injectable copolymer solution will allow the material to fill cracks in the cartilage after trauma. The mechanical properties of the nanocomposite are similar to that of native cartilage, as measured by compressive and shear testing. It thereby has the potential to mechanically stabilize and restore local structural integrity to acutely injured cartilage. Additionally, the insitu mineralization ensures good adhesion at the interface between the biomaterial and cartilage, as measured through tensile and shear testing. Therefore, we have successfully developed a new injectable insitu forming nanocomposite with mechanical properties of similar magnitude to that of native cartilage, and which can bond well to native cartilage. This material has the potential to stabilize injured cartilage and prevent PTOA. PMID:21530694

  20. Toll-like receptor 4 signaling in neurons of trigeminal ganglion contributes to nociception induced by acute pulpitis in rats.

    PubMed

    Lin, Jia-Ji; Du, Yi; Cai, Wen-Ke; Kuang, Rong; Chang, Ting; Zhang, Zhuo; Yang, Yong-Xiang; Sun, Chao; Li, Zhu-Yi; Kuang, Fang

    2015-01-01

    Pain caused by acute pulpitis (AP) is a common symptom in clinical settings. However, its underlying mechanisms have largely remained unknown. Using AP model, we demonstrated that dental injury caused severe pulp inflammation with up-regulated serum IL-1β. Assessment from head-withdrawal reflex thresholds (HWTs) and open-field test demonstrated nociceptive response at 1 day post injury. A consistent up-regulation of Toll-like receptor 4 (TLR4) in the trigeminal ganglion (TG) ipsilateral to the injured pulp was found; and downstream signaling components of TLR4, including MyD88, TRIF and NF-κB, and cytokines such as TNF-α and IL-1β, were also increased. Retrograde labeling indicated that most TLR4 positve neuron in the TG innnervated the pulp and TLR4 immunoreactivity was mainly in the medium and small neurons. Double labeling showed that the TLR4 expressing neurons in the ipsilateral TG were TRPV1 and CGRP positive, but IB4 negative. Furthermore, blocking TLR4 by eritoran (TLR4 antagonist) in TGs of the AP model significantly down-regulated MyD88, TRIF, NF-κB, TNF-α and IL-1β production and behavior of nociceptive response. Our findings suggest that TLR4 signaling in TG cells, particularly the peptidergic TRPV1 neurons, plays a key role in AP-induced nociception, and indicate that TLR4 signaling could be a potential therapeutic target for orofacial pain. PMID:26224622

  1. Toll-like receptor 4 signaling in neurons of trigeminal ganglion contributes to nociception induced by acute pulpitis in rats

    PubMed Central

    Lin, Jia-Ji; Du, Yi; Cai, Wen-Ke; Kuang, Rong; Chang, Ting; Zhang, Zhuo; Yang, Yong-Xiang; Sun, Chao; Li, Zhu-Yi; Kuang, Fang

    2015-01-01

    Pain caused by acute pulpitis (AP) is a common symptom in clinical settings. However, its underlying mechanisms have largely remained unknown. Using AP model, we demonstrated that dental injury caused severe pulp inflammation with up-regulated serum IL-1β. Assessment from head-withdrawal reflex thresholds (HWTs) and open-field test demonstrated nociceptive response at 1 day post injury. A consistent up-regulation of Toll-like receptor 4 (TLR4) in the trigeminal ganglion (TG) ipsilateral to the injured pulp was found; and downstream signaling components of TLR4, including MyD88, TRIF and NF-κB, and cytokines such as TNF-α and IL-1β, were also increased. Retrograde labeling indicated that most TLR4 positve neuron in the TG innnervated the pulp and TLR4 immunoreactivity was mainly in the medium and small neurons. Double labeling showed that the TLR4 expressing neurons in the ipsilateral TG were TRPV1 and CGRP positive, but IB4 negative. Furthermore, blocking TLR4 by eritoran (TLR4 antagonist) in TGs of the AP model significantly down-regulated MyD88, TRIF, NF-κB, TNF-α and IL-1β production and behavior of nociceptive response. Our findings suggest that TLR4 signaling in TG cells, particularly the peptidergic TRPV1 neurons, plays a key role in AP-induced nociception, and indicate that TLR4 signaling could be a potential therapeutic target for orofacial pain. PMID:26224622

  2. Ca2+ toxicity and mitochondrial damage in acute pancreatitis: translational overview

    PubMed Central

    Maléth, József; Hegyi, Péter

    2016-01-01

    Acute pancreatitis (AP) is a leading cause of hospitalization among non-malignant gastrointestinal disorders. The mortality of severe AP can reach 30–50%, which is most probably owing to the lack of specific treatment. Therefore, AP is a major healthcare problem, which urges researchers to identify novel drug targets. Studies from the last decades highlighted that the toxic cellular Ca2+ overload and mitochondrial damage are key pathogenic steps in the disease development affecting both acinar and ductal cell functions. Moreover, recent observations showed that modifying the cellular Ca2+ signalling might be beneficial in AP. The inhibition of Ca2+ release from the endoplasmic reticulum or the activity of plasma membrane Ca2+ influx channels decreased the severity of AP in experimental models. Similarly, inhibition of mitochondrial permeability transition pore (MPTP) opening also seems to improve the outcome of AP in in vivo animal models. At the moment MPTP blockers are under detailed clinical investigation to test whether interventions in MPTP openings and/or Ca2+ homeostasis of the cells can be specific targets in prevention or treatment of cell damage in AP. This article is part of the themed issue ‘Evolution brings Ca2+ and ATP together to control life and death’. PMID:27377719

  3. Ca2+ toxicity and mitochondrial damage in acute pancreatitis: translational overview.

    PubMed

    Maléth, József; Hegyi, Péter

    2016-08-01

    Acute pancreatitis (AP) is a leading cause of hospitalization among non-malignant gastrointestinal disorders. The mortality of severe AP can reach 30-50%, which is most probably owing to the lack of specific treatment. Therefore, AP is a major healthcare problem, which urges researchers to identify novel drug targets. Studies from the last decades highlighted that the toxic cellular Ca(2+) overload and mitochondrial damage are key pathogenic steps in the disease development affecting both acinar and ductal cell functions. Moreover, recent observations showed that modifying the cellular Ca(2+) signalling might be beneficial in AP. The inhibition of Ca(2+) release from the endoplasmic reticulum or the activity of plasma membrane Ca(2+) influx channels decreased the severity of AP in experimental models. Similarly, inhibition of mitochondrial permeability transition pore (MPTP) opening also seems to improve the outcome of AP in in vivo animal models. At the moment MPTP blockers are under detailed clinical investigation to test whether interventions in MPTP openings and/or Ca(2+) homeostasis of the cells can be specific targets in prevention or treatment of cell damage in AP.This article is part of the themed issue 'Evolution brings Ca(2+) and ATP together to control life and death'. PMID:27377719

  4. Maltol, a Food Flavoring Agent, Attenuates Acute Alcohol-Induced Oxidative Damage in Mice

    PubMed Central

    Han, Ye; Xu, Qi; Hu, Jiang-ning; Han, Xin-yue; Li, Wei; Zhao, Li-chun

    2015-01-01

    The purpose of this study was to evaluate the hepatoprotective effect of maltol, a food-flavoring agent, on alcohol-induced acute oxidative damage in mice. Maltol used in this study was isolated from red ginseng (Panax ginseng C.A Meyer) and analyzed by high performance liquid chromatography (HPLC) and mass spectrometry. For hepatoprotective activity in vivo, pretreatment with maltol (12.5, 25 and 50 mg/kg; 15 days) drastically prevented the elevated activities of aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP) and triglyceride (TG) in serum and the levels of malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) in liver tissue (p < 0.05). Meanwhile, the levels of hepatic antioxidant, such as catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) were elevated by maltol pretreatment, compared to the alcohol group (p < 0.05). Histopathological examination revealed that maltol pretreatment significantly inhibited alcohol-induced hepatocyte apoptosis and fatty degeneration. Interestingly, pretreatment of maltol effectively relieved alcohol-induced oxidative damage in a dose-dependent manner. Maltol appeared to possess promising anti-oxidative and anti-inflammatory capacities. It was suggested that the hepatoprotective effect exhibited by maltol on alcohol-induced liver oxidative injury may be due to its potent antioxidant properties. PMID:25608939

  5. Difference in transient ischemia-induced neuronal damage and glucose transporter-1 immunoreactivity in the hippocampus between adult and young gerbils

    PubMed Central

    Park, Seung Min; Lee, Jae-Chul; Chen, Bai Hui; Shin, Bich-Na; Cho, Jeong Hwi; Kim, In Hye; Park, Joon Ha; Won, Moo-Ho; Ahn, Ji Hyeon; Tae, Hyun-Jin; Shin, Myoung Cheol; Park, Chan Woo; Cho, Jun Hwi; Lee, Hui Young

    2016-01-01

    Objective(s): The alteration of glucose transporters is closely related with the pathogenesis of brain edema. We compared neuronal damage/death in the hippocampus between adult and young gerbils following transient cerebral ischemia/reperfusion and changes of glucose transporter-1(GLUT-1)-immunoreactive microvessels in their ischemic hippocampal CA1 region. Materials and Methods: Transient cerebral ischemia was developed by 5-min occlusion of both common carotid arteries. Neuronal damage was examined by cresyl violet staining, NeuN immunohistochemistry and Fluoro-Jade B histofluorescence staining and changes in GLUT-1 expression was carried out by immunohistochemistry. Results: About 90% of pyramidal neurons only in the adult CA1 region were damaged after ischemia/reperfusion; in the young, about 53 % of pyramidal neurons were damaged from 7 days after ischemia/reperfusion. The density of GLUT-1-immunoreactive microvessels was significantly higher in the young sham-group than that in the adult sham-group. In the ischemia-operated-groups, the density of GLUT-1-immunoreactive microvessels was significantly decreased in the adult and young at 1 and 4 days post-ischemia, respectively, thereafter, the density of GLUT-1-immunoreactive microvessels was gradually increased in both groups after ischemia/reperfusion. Conclusion: CA1 pyramidal neurons of the young gerbil were damaged much later than that in the adult and that GLUT-1-immunoreactive microvessels were significantly decreased later in the young. These data indicate that GLUT-1 might differently contribute to neuronal damage according to age after ischemic insults. PMID:27403259

  6. Effects of acute and chronic administration of fenproporex on DNA damage parameters in young and adult rats.

    PubMed

    Gonçalves, Cinara L; Rezin, Gislaine T; Ferreira, Gabriela K; Jeremias, Isabela C; Cardoso, Mariane R; Valvassori, Samira S; Munhoz, Bruna J P; Borges, Gabriela D; Bristot, Bruno N; Leffa, Daniela D; Andrade, Vanessa M; Quevedo, João; Streck, Emilio L

    2013-08-01

    Obesity is a chronic and multifactorial disease, whose prevalence is increasing in many countries. Pharmaceutical strategies for the treatment of obesity include drugs that regulate food intake, thermogenesis, fat absorption, and fat metabolism. Fenproporex is the second most commonly consumed amphetamine-based anorectic worldwide; this drug is rapidly converted in vivo into amphetamine, which is associated with neurotoxicity. In this context, the present study evaluated DNA damage parameters in the peripheral blood of young and adult rats submitted to an acute administration and chronic administration of fenproporex. In the acute administration, both young and adult rats received a single injection of fenproporex (6.25, 12.5 or 25 mg/kg i.p.) or vehicle. In the chronic administration, both young and adult rats received one daily injection of fenproporex (6.25, 12.5, or 25 mg/kg i.p.) or Tween for 14 days. 2 h after the last injection, the rats were killed by decapitation and their peripheral blood removed for evaluation of DNA damage parameters by alkaline comet assay. Our study showed that acute administration of fenproporex in young and adult rats presented higher levels of damage index and frequency in the DNA. However, chronic administration of fenproporex in young and adult rats did not alter the levels of DNA damage in both parameters of comet assay. The present findings showed that acute administration of fenproporex promoted damage in DNA, in both young and adult rats. Our results are consistent with other reports which showed that other amphetamine-derived drugs also caused DNA damage. We suggest that the activation of an efficient DNA repair mechanism may occur after chronic exposition to fenproporex. Our results are consistent with other reports that showed some amphetamine-derived drugs also caused DNA damage. PMID:23636618

  7. Acute protease supplementation effects on muscle damage and recovery across consecutive days of cycle racing.

    PubMed

    Shing, Cecilia M; Chong, Suzzen; Driller, Matthew W; Fell, James W

    2016-01-01

    Bromelain, a mixture of proteases obtained from pineapples, has been demonstrated to reduce exercise-induced muscle damage and inflammation, enhancing recovery. This investigation aimed to establish if markers of muscle damage and testosterone were influenced by acute bromelain supplementation in competitive cyclists taking part in a six-day cycle stage race. Fifteen highly trained cyclists [age: 22, [Formula: see text] = 1.2 years, height: 1.79, [Formula: see text] = 0.01 m, body mass: 68.69, [Formula: see text] = 1.97 kg] were supplemented with either bromelain (1000 mg·day(-1)) (n = 8) or a placebo (n = 7) across six days of competitive racing in a randomised, double-blind, placebo-controlled trial. Blood was collected from each cyclist on days one, three and six of racing and analysed for creatine kinase (CK), myoglobin, lactate dehydrogenase (LDH) and testosterone. CK activity (P < 0.001, d = 17.4-18.8), LDH activity (P < 0.004, d = 0.5-2.5) and myoglobin concentration (P < 0.007, d = 3.4-4.8) were elevated from pre-race on days three and six of racing in both groups. Testosterone concentrations were significantly lower on the final day of racing (P = 0.03, d = 1.3) and there was a trend for bromelain to maintain testosterone concentrations across the race period (P = 0.05, d = 1.04-1.70) when compared to placebo. Fatigue rating was lower in the bromelain group on day four of racing (P = 0.01). Consecutive days of competitive cycling were associated with increased markers of muscle damage and a reduction in circulating testosterone across the race period. Bromelain supplementation reduced subjective feelings of fatigue and was associated with a trend to maintain testosterone concentration. PMID:25604346

  8. Administration of low dose estrogen attenuates gliosis and protects neurons in acute spinal cord injury in rats.

    PubMed

    Samantaray, Supriti; Das, Arabinda; Matzelle, Denise C; Yu, Shan P; Wei, Ling; Varma, Abhay; Ray, Swapan K; Banik, Naren L

    2016-03-01

    Spinal cord injury (SCI) is a debilitating condition with neurological deficits and loss of motor function that, depending on the severity, may lead to paralysis. The only treatment currently available is methylprednisolone, which is widely used and renders limited efficacy in SCI. Therefore, other therapeutic agents must be developed. The neuroprotective efficacy of estrogen in SCI was studied with a pre-clinical and pro-translational perspective. Acute SCI was induced in rats that were treated with low doses of estrogen (1, 5, 10, or 100 μg/kg) and compared with vehicle-treated injured rats or laminectomy control (sham) rats at 48 h post-SCI. Changes in gliosis and other pro-inflammatory responses, expression and activity of proteolytic enzymes (e.g., calpain, caspase-3), apoptosis of neurons in SCI, and cell death were monitored via Western blotting and immunohistochemistry. Negligible pro-inflammatory responses or proteolytic events and very low levels of neuronal death were found in sham rats. In contrast, vehicle-treated SCI rats showed profound pro-inflammatory responses with reactive gliosis, elevated expression and activity of calpain and caspase-3, elevated Bax:Bcl-2 ratio, and high levels of neuronal death in lesion and caudal regions of the injured spinal cord. Estrogen treatment at each dose reduced pro-inflammatory and proteolytic activities and protected neurons in the caudal penumbra in acute SCI. Estrogen treatment at 10 μg was found to be as effective as 100 μg in ameliorating the above parameters in injured animals. Results from this investigation indicated that estrogen at a low dose could be a promising therapeutic agent for treating acute SCI. Experimental studies with low dose estrogen therapy in acute spinal cord injury (SCI) demonstrated the potential for multi-active beneficial outcomes. Estrogen has been found to ameliorate several degenerative pathways following SCI. Thus, such early protective effects may even lead to functional

  9. Acute pressure on the sciatic nerve results in rapid inhibition of the wide dynamic range neuronal response

    PubMed Central

    2012-01-01

    Background Acute pressure on the sciatic nerve has recently been reported to provide rapid short-term relief of pain in patients with various pathologies. Wide dynamic range (WDR) neurons transmit nociceptive information from the dorsal horn to higher brain centers. In the present study, we examined the effect of a 2-min application of sciatic nerve pressure on WDR neuronal activity in anesthetized male Sprague–Dawley rats. Results Experiments were carried out on 41 male Sprague–Dawley albino rats weighing 160–280 grams. Dorsal horn WDR neurons were identified on the basis of characteristic responses to mechanical stimuli applied to the cutaneous receptive field. Acute pressure was applied for 2 min to the sciatic nerve using a small vascular clip. The responses of WDR neurons to three mechanical stimuli applied to the cutaneous receptive field were recorded before, and 2, 5 and 20 min after cessation of the 2-min pressure application on the sciatic nerve. Two-min pressure applied to the sciatic nerve caused rapid attenuation of the WDR response to pinching, pressure and brushing stimuli applied to the cutaneous receptive field. Maximal attenuation of the WDR response to pinching and pressure was noted 5 min after release of the 2-min pressure on the sciatic nerve. The mean firing rate decreased from 31.7±1.7 Hz to 13±1.4 Hz upon pinching (p < 0.001), from 31.2±2.3 Hz to 10.9±1.4 Hz (p < 0.001) when pressure was applied, and from 18.9±1.2 Hz to 7.6±1.1 Hz (p < 0.001) upon brushing. Thereafter, the mean firing rates gradually recovered. Conclusions Our results indicate that acute pressure applied to the sciatic nerve exerts a rapid inhibitory effect on the WDR response to both noxious and innocuous stimuli. Our results may partially explain the rapid analgesic effect of acute sciatic nerve pressure noted in clinical studies, and also suggest a new model for the study of pain. PMID:23211003

  10. Endogenous dynorphin protects against neurotoxin-elicited nigrostriatal dopaminergic neuron damage and motor deficits in mice

    PubMed Central

    2012-01-01

    Background The striato-nigral projecting pathway contains the highest concentrations of dynorphin in the brain. The functional role of this opioid peptide in the regulation of mesencephalic dopaminergic (DAergic) neurons is not clear. We reported previously that exogenous dynorphin exerts potent neuroprotective effects against inflammation-induced dopaminergic neurodegeneration in vitro. The present study was performed to investigate whether endogenous dynorphin has neuroprotective roles in vivo. Methods 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and methamphetamine (MA), two commonly used neurotoxins in rodent models of Parkinson’s disease, were administered to wild-type (Dyn+/+) and prodynorphin-deficient mice (Dyn−/−). We examined dopaminergic neurotoxicity by using an automated video tracking system, HPLC, immunocytochemistry, and reverse transcription and polymerase chain reaction (RT-PCR). Results Treatment with MPTP resulted in behavioral impairments in both strains. However, these impairments were more pronounced in Dyn-l- than in Dyn+/+. Dyn−/− showed more severe MPTP-induced dopaminergic neuronal loss in the substantia nigra and striatum than Dyn+/+. Similarly, the levels of dopamine and its metabolites in the striatum were depleted to a greater extent in Dyn−/− than in Dyn+/+. Additional mechanistic studies revealed that MPTP treatment caused a higher degree of microglial activation and M1 phenotype differentiation in Dyn−/− than in Dyn+/+. Consistent with these observations, prodynorphin deficiency also exacerbated neurotoxic effects induced by MA, although this effect was less pronounced than that of MPTP. Conclusions The in vivo results presented here extend our previous in vitro findings and further indicate that endogenous dynorphin plays a critical role in protecting dopaminergic neurons through its anti-inflammatory effects. PMID:22695044

  11. Long-term neuronal damage and recovery after a single dose of MDMA: expression and distribution of serotonin transporter in the rat brain.

    PubMed

    Kirilly, Eszter

    2010-09-01

    "Ecstasy", 3,4-methylenedioxymethamphetamine (MDMA), an amphetamine analogue is one of the most widely used recreational drugs. In spite of the fact that neurotoxic effects of MDMA has been found in several species from rodents to non-human primates, and results increasingly point to damage also in human MDMA users, data about the sensitivity of different brain areas and the recovery after neuronal damage are scarce. Serotonin transporter (5-HTT) mRNA in the raphe nuclei also has not been examined. Humans with genetic predisposition for the slow metabolism of MDMA, the so-called "poor metabolizers" of debrisoquin are at higher risk. Five- 9% of the Caucasian population is considered to carry this phenotype. These studies were carried out in Dark Agouti rats, a special strain that show decreased microsomal CYP2D1 isoenzyme activity, and thus may serve as a model of vulnerable human users. These works were designed to characterize MDMA-induced damage and recovery of the serotonergic system including sleep and morphological changes within 180 days. In our experiments we investigated the 5-HTT mRNA expression in the brainstem and medullary raphe nuclei, 5-HTT immunoreactive (IR) fibre densities in several brain areas, and 16 functional measures of sleep in response to a single dose of +/- MDMA (15mg\\kg). Furthermore, behavioural experiments were performed 21 days after MDMA treatment. We found similar changes in 5-HTT mRNA expression in the examined raphe nuclei, namely transient increases 7 days after MDMA treatment followed by transient decreases at 21 days. Significant (20-40%), widespread reductions in 5-HTT-IR fibre density were detected in most brain areas at 7 and 21 days after MDMA administration. All cortical, but only some brainstem areas were damaged. Parallel to the neuronal damage we observed significant reductions in rapid eye movement (REM) sleep latency, increased fragmentation of sleep and increases in delta power spectra in non-REM sleep. At 180 days

  12. Ceramide and neurodegeneration: Susceptibility of neurons and oligodendrocytes to cell damage and death

    PubMed Central

    Jana, Arundhati; Hogan, Edward L.; Pahan, Kalipada

    2009-01-01

    Neurodegenerative disorders are marked by extensive neuronal apoptosis and gliosis. Although several apoptosis-inducing agents have been described, understanding of the regulatory mechanisms underlying modes of cell death is incomplete. A major breakthrough in delineation of the mechanism of cell death came from elucidation of the sphingomyelin (SM)-ceramide pathway that has received worldwide attention in recent years. The SM pathway induces apoptosis, differentiation, proliferation, and growth arrest depending upon cell and receptor types, and on downstream targets. Sphingomyelin, a plasma membrane constituent, is abundant in mammalian nervous system, and ceramide, its primary catabolic product released by activation of either neutral or acidic sphingomyelinase, serves as a potential lipid second messenger or mediator molecule modulating diverse cellular signaling pathways. Neutral sphingomyelinase (NSMase) is a key enzyme in the regulated activation of the SM cycle and is particularly sensitive to oxidative stress. In a context of increasing clarification of the mechanisms of neurodegeneration, we thought that it would be useful to review details of recent findings that we and others have made concerning different pro-apoptotic neurotoxins including proinflammatory cytokines, hypoxia-induced SM hydrolysis and ceramide production that induce cell death in human primary neurons and primary oligodendrocytes: redox sensitive events. What has and is emerging is a vista of therapeutically important ceramide regulation affecting a variety of different neurodegenerative and neuroinflammatory disorders. PMID:19147160

  13. BDNF Increases Survival and Neuronal Differentiation of Human Neural Precursor Cells Cotransplanted with a Nanofiber Gel to the Auditory Nerve in a Rat Model of Neuronal Damage

    PubMed Central

    Jiao, Yu; Palmgren, Björn; Novozhilova, Ekaterina; Englund Johansson, Ulrica; Spieles-Engemann, Anne L.; Kale, Ajay; Stupp, Samuel I.; Olivius, Petri

    2014-01-01

    Objectives. To study possible nerve regeneration of a damaged auditory nerve by the use of stem cell transplantation. Methods. We transplanted HNPCs to the rat AN trunk by the internal auditory meatus (IAM). Furthermore, we studied if addition of BDNF affects survival and phenotypic differentiation of the grafted HNPCs. A bioactive nanofiber gel (PA gel), in selected groups mixed with BDNF, was applied close to the implanted cells. Before transplantation, all rats had been deafened by a round window niche application of β-bungarotoxin. This neurotoxin causes a selective toxic destruction of the AN while keeping the hair cells intact. Results. Overall, HNPCs survived well for up to six weeks in all groups. However, transplants receiving the BDNF-containing PA gel demonstrated significantly higher numbers of HNPCs and neuronal differentiation. At six weeks, a majority of the HNPCs had migrated into the brain stem and differentiated. Differentiated human cells as well as neurites were observed in the vicinity of the cochlear nucleus. Conclusion. Our results indicate that human neural precursor cells (HNPC) integration with host tissue benefits from additional brain derived neurotrophic factor (BDNF) treatment and that these cells appear to be good candidates for further regenerative studies on the auditory nerve (AN). PMID:25243135

  14. Acute stress enhances adult rat hippocampal neurogenesis and activation of newborn neurons via secreted astrocytic FGF2

    PubMed Central

    Kirby, Elizabeth D; Muroy, Sandra E; Sun, Wayne G; Covarrubias, David; Leong, Megan J; Barchas, Laurel A; Kaufer, Daniela

    2013-01-01

    Stress is a potent modulator of the mammalian brain. The highly conserved stress hormone response influences many brain regions, particularly the hippocampus, a region important for memory function. The effect of acute stress on the unique population of adult neural stem/progenitor cells (NPCs) that resides in the adult hippocampus is unclear. We found that acute stress increased hippocampal cell proliferation and astrocytic fibroblast growth factor 2 (FGF2) expression. The effect of acute stress occurred independent of basolateral amygdala neural input and was mimicked by treating isolated NPCs with conditioned media from corticosterone-treated primary astrocytes. Neutralization of FGF2 revealed that astrocyte-secreted FGF2 mediated stress-hormone-induced NPC proliferation. 2 weeks, but not 2 days, after acute stress, rats also showed enhanced fear extinction memory coincident with enhanced activation of newborn neurons. Our findings suggest a beneficial role for brief stress on the hippocampus and improve understanding of the adaptive capacity of the brain. DOI: http://dx.doi.org/10.7554/eLife.00362.001 PMID:23599891

  15. Microcavitation as a Neuronal Damage Mechanism in Blast Traumatic Brain Injury

    NASA Astrophysics Data System (ADS)

    Franck, Christian; Estrada, Jonathan

    2015-11-01

    Blast traumatic brain injury (bTBI) is a leading cause of injury in the armed forces. Diffuse axonal injury, the hallmark feature of blunt TBI, has been investigated in direct mechanical loading conditions. However, recent evidence suggests inertial cavitation as a possible bTBI mechanism, particularly in the case of exposure to blasts. Cavitation damage to free surfaces has been well-studied, but bubble interactions within confined 3D environments, in particular their stress and strain signatures are not well understood. The structural damage due to cavitation in living tissues - particularly at the cellular level - are incompletely understood, in part due to the rapid bubble formation and deformation strain rates of up to ~ 105-106 s-1. This project aims to characterize material damage in 2D and 3D cell culture environments by utilizing a novel high-speed red-blue diffraction assisted image correlation method at speeds of up to 106 frames per second. We gratefully acknowledge funding from the Office of Naval Research (POC: Dr. Tim Bentley).

  16. Diverse impact of acute and long-term extracellular proteolytic activity on plasticity of neuronal excitability

    PubMed Central

    Wójtowicz, Tomasz; Brzdąk, Patrycja; Mozrzymas, Jerzy W.

    2015-01-01

    Learning and memory require alteration in number and strength of existing synaptic connections. Extracellular proteolysis within the synapses has been shown to play a pivotal role in synaptic plasticity by determining synapse structure, function, and number. Although synaptic plasticity of excitatory synapses is generally acknowledged to play a crucial role in formation of memory traces, some components of neural plasticity are reflected by nonsynaptic changes. Since information in neural networks is ultimately conveyed with action potentials, scaling of neuronal excitability could significantly enhance or dampen the outcome of dendritic integration, boost neuronal information storage capacity and ultimately learning. However, the underlying mechanism is poorly understood. With this regard, several lines of evidence and our most recent study support a view that activity of extracellular proteases might affect information processing in neuronal networks by affecting targets beyond synapses. Here, we review the most recent studies addressing the impact of extracellular proteolysis on plasticity of neuronal excitability and discuss how enzymatic activity may alter input-output/transfer function of neurons, supporting cognitive processes. Interestingly, extracellular proteolysis may alter intrinsic neuronal excitability and excitation/inhibition balance both rapidly (time of minutes to hours) and in long-term window. Moreover, it appears that by cleavage of extracellular matrix (ECM) constituents, proteases may modulate function of ion channels or alter inhibitory drive and hence facilitate active participation of dendrites and axon initial segments (AISs) in adjusting neuronal input/output function. Altogether, a picture emerges whereby both rapid and long-term extracellular proteolysis may influence some aspects of information processing in neurons, such as initiation of action potential, spike frequency adaptation, properties of action potential and dendritic

  17. Protective effects of Alpha-lipoic acid on MeHg-induced oxidative damage and intracellular Ca(2+) dyshomeostasis in primary cultured neurons.

    PubMed

    Yang, Tianyao; Xu, Zhaofa; Liu, Wei; Xu, Bin; Deng, Yu

    2016-05-01

    Methylmercury (MeHg) is one of the ubiquitous environmental toxicant that leads to long-lasting neurological deficits in animals and humans. However, the mechanisms of MeHg-induced neuronal cell death are incompletely understood. Treatment of neuronal cells with MeHg (0-2 μM) for 0.5-12 h, or pretreated with LA (12.5-100 μM) for 0.5-6 h resulted in toxic effects of primary cultured neurons concentration- and time-dependently. For further experiments, 12.5, 25, and 50 μM of LA pretreatment for 3 h followed by 1 μM MeHg for 6 h were performed for the examination of the responses of neurons. Exposure of MeHg resulted in damages of neurons, which were shown by a loss of cell viability, and supported by high levels of lactate dehydrogenase (LDH) release, apoptosis, and morphological changes. In addition, neurons were sensitive to MeHg-mediated oxidative stress, a finding that is consistent with ROS over-production, leading to decrease Ca(2+)-ATPase activity and increase intracellular free calcium. Moreover, expressions of NMDA receptor subunits in neurons were down-regulated after MeHg exposure, and expression of NR2A mRNA and protein were much more sensitive to MeHg than those of NR1 and NR2B. On the contrary, pretreatment with LA presented a concentration-dependent prevention against MeHg-mediated cytotoxic effects of neurons. In conclusion, present results showed that oxidative stress and intracellular Ca(2+ )dyshomeostasis resulting from MeHg exposure contributed to neuronal injury. LA could attenuate MeHg-induced neuronal toxicity via its antioxidant properties in primary cultured neurons. PMID:26986620

  18. Dual Electrophysiological Recordings of Synaptically-evoked Astroglial and Neuronal Responses in Acute Hippocampal Slices

    PubMed Central

    Rouach, Nathalie

    2012-01-01

    Astrocytes form together with neurons tripartite synapses, where they integrate and modulate neuronal activity. Indeed, astrocytes sense neuronal inputs through activation of their ion channels and neurotransmitter receptors, and process information in part through activity-dependent release of gliotransmitters. Furthermore, astrocytes constitute the main uptake system for glutamate, contribute to potassium spatial buffering, as well as to GABA clearance. These cells therefore constantly monitor synaptic activity, and are thereby sensitive indicators for alterations in synaptically-released glutamate, GABA and extracellular potassium levels. Additionally, alterations in astroglial uptake activity or buffering capacity can have severe effects on neuronal functions, and might be overlooked when characterizing physiopathological situations or knockout mice. Dual recording of neuronal and astroglial activities is therefore an important method to study alterations in synaptic strength associated to concomitant changes in astroglial uptake and buffering capacities. Here we describe how to prepare hippocampal slices, how to identify stratum radiatum astrocytes, and how to record simultaneously neuronal and astroglial electrophysiological responses. Furthermore, we describe how to isolate pharmacologically the synaptically-evoked astroglial currents. PMID:23222635

  19. Acute and chronic watercress supplementation attenuates exercise-induced peripheral mononuclear cell DNA damage and lipid peroxidation.

    PubMed

    Fogarty, Mark C; Hughes, Ciara M; Burke, George; Brown, John C; Davison, Gareth W

    2013-01-28

    Pharmacological antioxidant vitamins have previously been investigated for a prophylactic effect against exercise-induced oxidative stress. However, large doses are often required and may lead to a state of pro-oxidation and oxidative damage. Watercress contains an array of nutritional compounds such as β-carotene and α-tocopherol which may increase protection against exercise-induced oxidative stress. The present randomised controlled investigation was designed to test the hypothesis that acute (consumption 2 h before exercise) and chronic (8 weeks consumption) watercress supplementation can attenuate exercise-induced oxidative stress. A total of ten apparently healthy male subjects (age 23 (SD 4) years, stature 179 (SD 10) cm and body mass 74 (SD 15) kg) were recruited to complete the 8-week chronic watercress intervention period (and then 8 weeks of control, with no ingestion) of the experiment before crossing over in order to compete the single-dose acute phase (with control, no ingestion). Blood samples were taken at baseline (pre-supplementation), at rest (pre-exercise) and following exercise. Each subject completed an incremental exercise test to volitional exhaustion following chronic and acute watercress supplementation or control. The main findings show an exercise-induced increase in DNA damage and lipid peroxidation over both acute and chronic control supplementation phases (P< 0.05 v. supplementation), while acute and chronic watercress attenuated DNA damage and lipid peroxidation and decreased H₂O₂ accumulation following exhaustive exercise (P< 0.05 v. control). A marked increase in the main lipid-soluble antioxidants (α-tocopherol, γ-tocopherol and xanthophyll) was observed following watercress supplementation (P< 0.05 v. control) in both experimental phases. These findings suggest that short- and long-term watercress ingestion has potential antioxidant effects against exercise-induced DNA damage and lipid peroxidation. PMID:22475430

  20. Effects of acute treadmill running at different intensities on activities of serotonin and corticotropin-releasing factor neurons, and anxiety- and depressive-like behaviors in rats.

    PubMed

    Otsuka, Tomomi; Nishii, Ayu; Amemiya, Seiichiro; Kubota, Natsuko; Nishijima, Takeshi; Kita, Ichiro

    2016-02-01

    Accumulating evidence suggests that physical exercise can reduce and prevent the incidence of stress-related psychiatric disorders, including depression and anxiety. Activation of serotonin (5-HT) neurons in the dorsal raphe nucleus (DRN) is implicated in antidepressant/anxiolytic properties. In addition, the incidence and symptoms of these disorders may involve dysregulation of the hypothalamic-pituitary-adrenal axis that is initiated by corticotropin-releasing factor (CRF) neurons in the hypothalamic paraventricular nucleus (PVN). Thus, it is possible that physical exercise produces its antidepressant/anxiolytic effects by affecting these neuronal activities. However, the effects of acute physical exercise at different intensities on these neuronal activation and behavioral changes are still unclear. Here, we examined the activities of 5-HT neurons in the DRN and CRF neurons in the PVN during 30 min of treadmill running at different speeds (high speed, 25 m/min; low speed, 15m/min; control, only sitting on the treadmill) in male Wistar rats, using c-Fos/5-HT or CRF immunohistochemistry. We also performed the elevated plus maze test and the forced swim test to assess anxiety- and depressive-like behaviors, respectively. Acute treadmill running at low speed, but not high speed, significantly increased c-Fos expression in 5-HT neurons in the DRN compared to the control, whereas high-speed running significantly enhanced c-Fos expression in CRF neurons in the PVN compared with the control and low-speed running. Furthermore, low-speed running resulted in decreased anxiety- and depressive-like behaviors compared with high-speed running. These results suggest that acute physical exercise with mild and low stress can efficiently induce optimal neuronal activation that is involved in the antidepressant/anxiolytic effects. PMID:26542811

  1. Neurochemical correlates of cyanide-induced hypoxic neuronal damage in vitro.

    PubMed

    Sher, P K

    1988-02-01

    Neuronal cortical cell cultures obtained from fetal mice were subjected to an hypoxic insult produced by sodium cyanide (1 mM) for 24 h. Neurochemical assays were performed 13-14 days after plating on intact cells in situ to determine if there was a specific pattern of cellular dysfunction in addition to morphologic change. Ro5-4864-displaceable benzodiazepine (BDZ) binding and high-affinity [3H] beta-alanine uptake were not reduced when compared to control values. However, specific and clonazepam-displaceable BDZ binding (81 +/- 4% and 50 +/- 9% of control values, respectively), high-affinity [3H]GABA uptake (75 +/- 2%), and choline acetyltransferase activity (82 +/- 2%) were significantly lower. When the data were expressed in terms of protein content, high-affinity [3H] beta-alanine uptake was significantly increased in cyanide-exposed and magnesium-treated cultures (123 +/- 5% and 117 +/- 3%, respectively) as was R05-4864-displaceable BDZ binding (152 +/- 14%), consistent with stimulation of nonneuronal BDZ binding and increased glial neurotransmitter uptake. Moreover, pretreatment of the cultures with magnesium effectively prevented both the morphologic and neurochemical evidence of hypoxic injury. These data lend further support to the notion that the release of excitatory neurotransmitters may mediate neurotoxicity in developing brain. PMID:2834659

  2. Structure of glutamate carboxypeptidase II, a drug target in neuronal damage and prostate cancer.

    PubMed

    Mesters, Jeroen R; Barinka, Cyril; Li, Weixing; Tsukamoto, Takashi; Majer, Pavel; Slusher, Barbara S; Konvalinka, Jan; Hilgenfeld, Rolf

    2006-03-22

    Membrane-bound glutamate carboxypeptidase II (GCPII) is a zinc metalloenzyme that catalyzes the hydrolysis of the neurotransmitter N-acetyl-L-aspartyl-L-glutamate (NAAG) to N-acetyl-L-aspartate and L-glutamate (which is itself a neurotransmitter). Potent and selective GCPII inhibitors have been shown to decrease brain glutamate and provide neuroprotection in preclinical models of stroke, amyotrophic lateral sclerosis, and neuropathic pain. Here, we report crystal structures of the extracellular part of GCPII in complex with both potent and weak inhibitors and with glutamate, the product of the enzyme's hydrolysis reaction, at 2.0, 2.4, and 2.2 A resolution, respectively. GCPII folds into three domains: protease-like, apical, and C-terminal. All three participate in substrate binding, with two of them directly involved in C-terminal glutamate recognition. One of the carbohydrate moieties of the enzyme is essential for homodimer formation of GCPII. The three-dimensional structures presented here reveal an induced-fit substrate-binding mode of this key enzyme and provide essential information for the design of GCPII inhibitors useful in the treatment of neuronal diseases and prostate cancer. PMID:16467855

  3. Obatoclax Potentiates the Cytotoxic Effect of Cytarabine on Acute Myeloid Leukemia Cells by Enhancing DNA Damage

    PubMed Central

    Xie, Chengzhi; Edwards, Holly; Caldwell, J. Timothy; Wang, Guan; Taub, Jeffrey W.; Ge, Yubin

    2014-01-01

    Resistance to cytarabine and anthracycline-based chemotherapy is a major cause of treatment failure for acute myeloid leukemia (AML) patients. Overexpression of Bcl-2, Bcl-xL, and/or Mcl-1 has been associated with chemoresistance in AML cell lines and with poor clinical outcome of AML patients. Thus, inhibitors of anti-apoptotic Bcl-2 family proteins could be novel therapeutic agents. In this study, we investigated how clinically achievable concentrations of obatoclax, a pan-Bcl-2 inhibitor, potentiate the antileukemic activity of cytarabine in AML cells. MTT assays in AML cell lines and diagnostic blasts, as well as flow cytometry analyses in AML cell lines revealed synergistic antileukemic activity between cytarabine and obatoclax. Bax activation was detected in the combined, but not the individual, drug treatments. This was accompanied by significantly increased loss of mitochondrial membrane potential. Most importantly, in AML cells treated with the combination, enhanced early induction of DNA double-strand breaks (DSBs) preceded a decrease of Mcl-1 levels, nuclear translocation of Bcl-2, Bcl-xL, and Mcl-1, and apoptosis. These results indicate that obatoclax enhances cytarabine-induced apoptosis by enhancing DNA DSBs. This novel mechanism provides compelling evidence for the clinical use of BH3 mimetics in combination with DNA-damaging agents in AML and possibly a broader range of malignancies. PMID:25308513

  4. γ-Oryzanol protects against acute cadmium-induced oxidative damage in mice testes.

    PubMed

    Spiazzi, Cristiano C; Manfredini, Vanusa; Barcellos da Silva, Fabiana E; Flores, Erico M M; Izaguirry, Aryele P; Vargas, Laura M; Soares, Melina B; Santos, Francielli W

    2013-05-01

    Cadmium is a non-essential heavy metal that is present at low levels mainly in food and water and also in cigar smoke. The present study evaluated the testicular damage caused by acute cadmium exposure and verified the protective role of γ-oryzanol (ORY). Mice were administrated with a single dose of 2.5mg/kg of CdCl2, and then treated with ORY (50mM in canola oil, 5mL/kg). Testes were removed after 24h and tested for lipid peroxidation (TBARS), protein carbonylation, DNA breakage, ascorbic acid, cadmium and non-proteic thiols contents, and for the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST) and δ-aminolevulic acid dehydratase (δ-ALA-D). Cadmium presented a significant alteration in all parameters, except GPx and CAT activities. Therapy reduced in a slight degree cadmium concentration in testes (around 23%). ORY restored SOD and GST activities as well as TBARS production to the control levels. Furthermore, ORY partially recovered δ-ALA-D activity inhibited by cadmium. This study provides the first evidence on the therapeutic properties of ORY in protecting against cadmium-induced testicular toxicity. PMID:23395783

  5. Effect of hyperbaric oxygenation on mitochondrial function of neuronal cells in the cortex of neonatal rats after hypoxic-ischemic brain damage

    PubMed Central

    Yang, L.; Hei, M.Y.; Dai, J.J.; Hu, N.; Xiang, X.Y.

    2016-01-01

    The timing and mechanisms of protection by hyperbaric oxygenation (HBO) in hypoxic-ischemic brain damage (HIBD) have only been partially elucidated. We monitored the effect of HBO on the mitochondrial function of neuronal cells in the cerebral cortex of neonatal rats after HIBD. Neonatal Sprague-Dawley rats (total of 360 of both genders) were randomly divided into normal control, HIBD, and HIBD+HBO groups. The HBO treatment began immediately after hypoxia-ischemia (HI) and continued once a day for 7 consecutive days. Animals were euthanized 0, 2, 4, 6, and 12 h post-HI to monitor the changes in mitochondrial membrane potential (ΔΨm) occurring soon after a single dose of HBO treatment, as well as 2, 3, 4, 5, 6, and 7 days post-HI to study ΔΨm changes after a series of HBO treatments. Fluctuations in ΔΨm were observed in the ipsilateral cortex in both HIBD and HIBD+HBO groups. Within 2 to 12 h after HI insult, the ΔΨm of the HIBD and HIBD+HBO groups recovered to some extent. A secondary drop in ΔΨm was observed in both groups during the 1-4 days post-HI period, but was more severe in the HIBD+HBO group. There was a secondary recovery of ΔΨm observed in the HIBD+HBO group, but not in the HIBD group, during the 5-7 days period after HI insult. HBO therapy may not lead to improvement of neural cell mitochondrial function in the cerebral cortex in the early stage post-HI, but may improve it in the sub-acute stage post-HI. PMID:27119428

  6. Effect of hyperbaric oxygenation on mitochondrial function of neuronal cells in the cortex of neonatal rats after hypoxic-ischemic brain damage.

    PubMed

    Yang, L; Hei, M Y; Dai, J J; Hu, N; Xiang, X Y

    2016-01-01

    The timing and mechanisms of protection by hyperbaric oxygenation (HBO) in hypoxic-ischemic brain damage (HIBD) have only been partially elucidated. We monitored the effect of HBO on the mitochondrial function of neuronal cells in the cerebral cortex of neonatal rats after HIBD. Neonatal Sprague-Dawley rats (total of 360 of both genders) were randomly divided into normal control, HIBD, and HIBD+HBO groups. The HBO treatment began immediately after hypoxia-ischemia (HI) and continued once a day for 7 consecutive days. Animals were euthanized 0, 2, 4, 6, and 12 h post-HI to monitor the changes in mitochondrial membrane potential (ΔΨm) occurring soon after a single dose of HBO treatment, as well as 2, 3, 4, 5, 6, and 7 days post-HI to study ΔΨm changes after a series of HBO treatments. Fluctuations in ΔΨm were observed in the ipsilateral cortex in both HIBD and HIBD+HBO groups. Within 2 to 12 h after HI insult, the ΔΨm of the HIBD and HIBD+HBO groups recovered to some extent. A secondary drop in ΔΨm was observed in both groups during the 1-4 days post-HI period, but was more severe in the HIBD+HBO group. There was a secondary recovery of ΔΨm observed in the HIBD+HBO group, but not in the HIBD group, during the 5-7 days period after HI insult. HBO therapy may not lead to improvement of neural cell mitochondrial function in the cerebral cortex in the early stage post-HI, but may improve it in the sub-acute stage post-HI. PMID:27119428

  7. EGFR mediates astragaloside IV-induced Nrf2 activation to protect cortical neurons against in vitro ischemia/reperfusion damages

    SciTech Connect

    Gu, Da-min; Lu, Pei-Hua; Zhang, Ke; Wang, Xiang; Sun, Min; Chen, Guo-Qian; Wang, Qiong

    2015-02-13

    In this study, we tested the potential role of astragaloside IV (AS-IV) against oxygen and glucose deprivation/re-oxygenation (OGD/R)-induced damages in murine cortical neurons, and studied the associated signaling mechanisms. AS-IV exerted significant neuroprotective effects against OGD/R by reducing reactive oxygen species (ROS) accumulation, thereby attenuating oxidative stress and neuronal cell death. We found that AS-IV treatment in cortical neurons resulted in NF-E2-related factor 2 (Nrf2) signaling activation, evidenced by Nrf2 Ser-40 phosphorylation, and its nuclear localization, as well as transcription of antioxidant-responsive element (ARE)-regulated genes: heme oxygenase-1 (HO-1), NAD(P)H:quinone oxidoreductase 1 (NQO-1) and sulphiredoxin 1 (SRXN-1). Knockdown of Nrf2 through lentiviral shRNAs prevented AS-IV-induced ARE genes transcription, and abolished its anti-oxidant and neuroprotective activities. Further, we discovered that AS-IV stimulated heparin-binding-epidermal growth factor (HB-EGF) release to trans-activate epidermal growth factor receptor (EGFR) in cortical neurons. Blockage or silencing EGFR prevented Nrf2 activation by AS-IV, thus inhibiting AS-IV-mediated anti-oxidant and neuroprotective activities against OGD/R. In summary, AS-IV protects cortical neurons against OGD/R damages through activating of EGFR-Nrf2 signaling. - Highlights: • Pre-treatment of astragaloside IV (AS-IV) protects murine cortical neurons from OGD/R. • AS-IV activates Nrf2-ARE signaling in murine cortical neurons. • Nrf2 is required for AS-IV-mediated anti-oxidant and neuroprotective activities. • AS-IV stimulates HB-EGF release to trans-activate EGFR in murine cortical neurons. • EGFR mediates AS-IV-induced Nrf2 activation and neuroprotection against OGD/R.

  8. Widespread neuronal damage and cognitive dysfunction in spinocerebellar ataxia type 3.

    PubMed

    Lopes, Tátila Martins; D'Abreu, Anelyssa; França, Marcondes Cavalcante; Yasuda, Clarissa Lin; Betting, Luiz Eduardo; Samara, Adriana Bastos; Castellano, Gabriela; Somazz, Júlio César; Balthazar, Marcio Luiz Figueredo; Lopes-Cendes, Iscia; Cendes, Fernando

    2013-09-01

    Previous studies demonstrated cognitive impairments in spinocerebellar ataxia type 3 (SCA3/MJD); however, there is no consensus about the cognitive domains affected and the correlation with structural brain abnormalities. We investigated the neuropsychological profile and 3T-MRI findings, including high-resolution T1-images, diffusion tensor imaging and magnetic resonance spectroscopy of 32 patients with SCA3/MJD and 32 age-, gender- and educational level-matched healthy controls. We reviewed patients' clinical history and CAG repeat length, and performed assessment and rating of ataxia (SARA)-Brazilian version and the neuropsychiatric inventory. Patients presented worse performance in episodic and working memory and Beck inventories (depression and anxiety). SCA3/MJD patients had a reduction of gray matter volume (GM) in the cerebellum, putamen, cingulum, precentral and parietal lobe. A positive correlation was identified between the cognitive findings and GM of temporal, frontal, parietal, culmen and insula. We observed positive correlation between the brainstem's fractional anisotropy and digit span-forward. The following cerebellar metabolite groups (measured relative to creatine) were reduced in patients: N-acetyl-aspartate (NAA), NAA + N-acetyl-aspartate-glutamate and glutamate + glutamine (Glx). We found a positive correlation between Corsi's block-tapping task forward with Glx; semantic verbal fluency with phosphorylcholine and glycerophosphorylcholine; digits span-forward with NAA. The cognitive impairments in SCA3/MJD are associated not only with cerebellar and brainstem abnormalities, but also with neuroimaging evidence of diffuse neuronal and axonal dysfunction, particularly in temporal, frontal, parietal and insular areas. PMID:23775343

  9. Increased lysosomal biogenesis in activated microglia and exacerbated neuronal damage after traumatic brain injury in progranulin-deficient mice.

    PubMed

    Tanaka, Y; Matsuwaki, T; Yamanouchi, K; Nishihara, M

    2013-10-10

    Progranulin (PGRN) is known to play a role in the pathogenesis of neurodegenerative diseases. Recently, it has been demonstrated that patients with the homozygous mutation in the GRN gene present with neuronal ceroid lipofuscinosis, and there is growing evidence that PGRN is related to lysosomal function. In the present study, we investigated the possible role of PGRN in the lysosomes of activated microglia in the cerebral cortex after traumatic brain injury (TBI). We showed that the mouse GRN gene has two possible coordinated lysosomal expression and regulation (CLEAR) sequences that bind to transcription factor EB (TFEB), a master regulator of lysosomal genes. PGRN was colocalized with Lamp1, a lysosomal marker, and Lamp1-positive areas in GRN-deficient (KO) mice were significantly expanded compared with wild-type (WT) mice after TBI. Expression of all the lysosome-related genes examined in KO mice was significantly higher than that in WT mice. The number of activated microglia with TFEB localized to the nucleus was also significantly increased in KO as compared with WT mice. Since the TFEB translocation is regulated by the mammalian target of rapamycin complex 1 (mTORC1) activity in the lysosome, we compared ribosomal S6 kinase 1 (S6K1) phosphorylation that reflects mTORC1 activity. S6K1 phosphorylation in KO mice was significantly lower than that in WT mice. In addition, the number of nissl-positive and fluoro-jade B-positive cells around the injury was significantly decreased and increased, respectively, in KO as compared with WT mice. These results suggest that PGRN localized in the lysosome is involved in the activation of mTORC1, and its deficiency leads to increased TFEB nuclear translocation with a resultant increase in lysosomal biogenesis in activated microglia and exacerbated neuronal damage in the cerebral cortex after TBI. PMID:23830905

  10. Resveratrol protects β amyloid-induced oxidative damage and memory associated proteins in H19-7 hippocampal neuronal cells.

    PubMed

    Rege, Shraddha D; Geetha, Thangiah; Broderick, Tom L; Babu, Jeganathan Ramesh

    2015-01-01

    Resveratrol (trans-3, 5, 4'-trihydroxystilbene) is a polyphenolic phytoalexin known to exhibit antioxidant and neuroprotective effects in several experimental models. Amyloid β peptide (Aβ), a core component of extracellular senile plaques accumulates in the brains of patients with Alzheimer's disease and is related to the development of cognitive impairment and neuronal loss. The present study evaluates the neuroprotective action of resveratrol on Aβ-induced oxidative stress and memory loss. Cultured rat hippocampal H19-7 neuronal cell line was pretreated with 75 μM of resveratrol for 2 hrs followed by 25 μM of Aβ (1-40) for 24 hrs. H19-7 cells treated with Aβ exhibited increased lipid peroxide levels. Enzymatic antioxidants including superoxide dismutase, catalase, glutathione reductase, and non-enzymatic antioxidants such as tocopherol, ascorbic acid and glutathione were decreased in the Aβ treated group when compared to the control group. Aβ treatment also increased the expression of total tau as well as phosphorylated forms of tau (CP13, S202/205; PHF1, S396/404) and decreased the expression of insulin degrading enzyme (IDE), phosphoglycogen synthase kinase 3β involved in Aβ degradation and tau hyper phosphorylation. Expression of PSD-95 and Arc proteins, essential for synaptic maturity and plasticity, was decreased by Aβ treatment. Resveratrol treatment attenuated the accumulation of lipid peroxide levels, up-regulated the antioxidant activities and improved the expression of memory-associated proteins in Aβ treated H19-7 cells. These findings highlight the neuroprotective effect of resveratrol in preventing Aβ-induced oxidative damage and memory loss in vitro. PMID:25654502

  11. Hepatoprotective Effect of Otostegia persica Boiss. Shoot Extract on Carbon Tetrachloride-Induced Acute Liver Damage in Rats

    PubMed Central

    Nasiri Bezenjani, Sedighe; Pouraboli, Iran; Malekpour Afshar, Reza; Mohammadi, Gholamabbas

    2012-01-01

    In this study, the hepatoprotective effect of the methanol extract of aerial parts (shoot) from Otostegia persica Boiss (Golder) was investigated against the carbon tetrachloride (CCl4)-induced acute hepatotoxicity in male rats. Liver damage was induced through the oral administration of 50% CCl4 in liquid paraffin (2.5 mL/Kg bw, per os) 60 min after the administration of the methanol extract of O. persica shoot (in 200, 300, 400 mg/Kg bw doses) and assessed using biochemical parameters (plasma and liver tissue malondialdehyde (MDA), transaminase enzyme levels in plasma [aspartate transaminase (AST), alanine aminotransferase (ALT)] and liver glutathione (GSH) levels). Results show that the methanol extract of O. persica shoot is active at 300 mg/Kg (per os) and it possess remarkable antioxidant and hepatoprotective activities. Additionally, histopathological studies verified the effectiveness of this dose of extract in acute liver damage prevention. PMID:24250558

  12. Social interaction attenuates the extent of secondary neuronal damage following closed head injury in mice

    PubMed Central

    Doulames, Vanessa M.; Vilcans, Meghan; Lee, Sangmook; Shea, Thomas B.

    2015-01-01

    Recovery following Traumatic Brain Injury (TBI) can vary tremendously among individuals. Lifestyle following injury, including differential social interactions, may modulate the extent of secondary injury following TBI. To examine this possibility under controlled conditions, closed head injury (CHI) was induced in C57Bl6 mice using a standardized weight drop device after which mice were either housed in isolation or with their original cagemates (“socially-housed”) for 4 weeks. CHI transiently impaired novel object recognition (NOR) in both isolated and social mice, confirming physical and functional injury. By contrast, Y maze navigation was impaired in isolated but not social mice at 1–4 weeks post CHI. CHI increased excitotoxic signaling in hippocampal slices from all mice, which was transiently exacerbated by isolation at 2 weeks post CHI. CHI slightly increased reactive oxygen species and did not alter levels of amyloid beta (Abeta), total or phospho-tau, total or phosphorylated neurofilaments. CHI increased serum corticosterone in both groups, which was exacerbated by isolation. These findings support the hypothesis that socialization may attenuate secondary damage following TBI. In addition, a dominance hierarchy was noted among socially-housed mice, in which the most submissive mouse displayed indices of stress in the above analyses that were statistically identical to those observed for isolated mice. This latter finding underscores that the nature and extent of social interaction may need to vary among individuals to provide therapeutic benefit. PMID:26528156

  13. The influence of acute or chronic nicotine treatment on ethanol-induced gastric mucosal damage in rats.

    PubMed

    Cho, C H; Chen, B W; Hui, W M; Lam, S K

    1990-01-01

    The influences of acute or chronic nicotine pretreatment on ethanol-induced changes on gastric secretion, mucosal blood flow (GMBF), and glandular mucosal damage were studied in anesthetized rats. Ethanol administration decreased gastric acid secretion and GMBF, which were accompanied by a marked increase in gastric mucosal damage. Acute nicotine incubation 2 or 4 mg dose-dependently elevated both the titratable acid in the luminal solution and the gastric secretory volume; it also prevented the depressive action on GMBF and gastric mucosal damage in ethanol-treated animals. Chronic nicotine treatment for 10 days reduced the inhibitory action of ethanol on gastric acid secretion; the higher dose (25 micrograms/ml drinking water) potentiated the decrease of GMBF and the ulcerogenic property of ethanol. However, chronic treatment with the lower dose (5 micrograms/ml drinking water) had the opposite effects; it also markedly increased the gastric secretory volume. It is concluded that acute nicotine pretreatment elevates, whereas chronic nicotine pretreatment differentially affects GMBF. These effects could account for their protective or preventive actions on ethanol ulceration. The increase in nonacid gastric secretory volume by nicotine could partially explain its antiulcer effect. Furthermore, the acid secretory state of the stomach appears unrelated to the ulcerogenic property of ethanol. PMID:2295286

  14. A LAT-associated function reduces productive-cycle gene expression during acute infection of murine sensory neurons with herpes simplex virus type 1.

    PubMed Central

    Garber, D A; Schaffer, P A; Knipe, D M

    1997-01-01

    Herpes simplex virus (HSV) persists in the human population by establishing long-term latent infections followed by periodic reactivation and transmission. Latent infection of sensory neurons is characterized by repression of viral productive-cycle gene expression, with abundant transcription limited to a single locus that encodes the latency-associated transcripts (LATs). We have observed that LAT- deletion mutant viruses express viral productive-cycle genes in greater numbers of murine trigeminal ganglion neurons than LAT+ HSV type 1 at early times during acute infection but show reduced reactivation from latent infection. Thus, a viral function associated with the LAT region exerts an effect at an early stage of neuronal infection to reduce productive-cycle viral gene expression. These results provide the first evidence that the virus plays an active role in down-regulating productive infection during acute infection of sensory neurons. The effect of down-regulation of productive-cycle gene expression during acute infection may contribute to viral evasion from the host immune responses and to reduced cytopathic effects, thereby facilitating neuronal survival and the establishment of latency. PMID:9223478

  15. The effects of acute alcohol consumption and eccentric muscle damage on neuromuscular function.

    PubMed

    Barnes, Matthew J; Mündel, Toby; Stannard, Stephen R

    2012-02-01

    Voluntary and electrically stimulated muscular performance was examined to identify the effects of acute alcohol consumption on neuromuscular function in the presence and absence of exercise-induced muscle damage (EIMD). After initial neuromuscular performance measures were made, 12 subjects completed a bout of eccentric exercise (EX) using the quadriceps muscles of 1 leg while the remaining 11 subjects did not exercise (NX). Subjects then consumed either an alcoholic beverage containing 1 g·kg(-1) body weight (ALC) or a nonalcoholic beverage (OJ). On another occasion the contralateral leg of both groups was tested and those in the EX group performed an equivalent bout of eccentric exercise after which the other beverage was consumed. Measurements of neuromuscular function were made pre-exercise and 36 and 60 h post-beverage consumption. Creatine kinase (CK) was measured pre-exercise and at 12, 36, and 60 h. Significantly greater (p < 0.01) decrements in maximal voluntary isometric contraction were observed with EX ALC at 36 and 60 h compared with EX OJ, and no change was seen in the NX group. Significant decreases in voluntary activation were observed at 36 h (p = 0.003) and 60 h (p = 0.01) with EX ALC only. Elevations in CK were observed at all posteccentric exercise time points (all p < 0.05) under both EX OJ and ALC. No change in electromyography or low-frequency fatigue was observed under either treatment in either group. These results suggest that decreased neural drive appears to contribute to alcohol's effect on the magnitude of EIMD-related decrements in voluntary force generation. PMID:22185621

  16. EphB1 Suppression in Acute Myelogenous Leukemia: Regulating the DNA Damage Control System

    PubMed Central

    Kampen, K.R.; Scherpen, F.J.G.; Garcia-Manero, G.; Yang, H.; Kaspers, G.J.L.; Cloos, J.; Zwaan, C.M.; van den Heuvel-Eibrink, M.M.; Kornblau, S.M.; De Bont, E.S.J.M.

    2016-01-01

    Loss of ephrin receptor (EphB1) expression may associate with aggressive cancer phenotypes; however, the mechanism of action remains unclear. To gain detailed insight into EphB1 function in acute myelogenous leukemia (AML), comprehensive analysis of EphB1 transcriptional regulation was conducted. In AML cells, EphB1 transcript was inversely correlated with EphB1 promoter methylation. The presence of EphB1 allowed EfnB1 ligand–mediated p53 DNA binding, leading to restoration of the DNA damage response (DDR) cascade by the activation of ATR, Chk1, p53, p21, p38, CDK1tyr15, and Bax, and downregulation of HSP27 and Bcl2. Comparatively, reintroduction of EphB1 expression in EphB1-methylated AML cells enhanced the same cascade of ATR, Chk1, p21, and CDK1tyr15, which consequently enforced programmed cell death. Interestingly, in pediatric AML samples, EphB1 peptide phosphorylation and mRNA expression were actively suppressed as compared with normal bone marrow, and a significant percentage of the primary AML specimens had EphB1 promoter hyper-methylation. Finally, EphB1 repression associated with a poor overall survival in pediatric AML. Combined, the contribution of EphB1 to the DDR system reveals a tumor-suppressor function for EphB1 in pediatric AML. Implications The tumor-suppressor function of EphB1 is clinically relevant across many malignancies, suggesting that EphB1 is an important regulator of common cancer cell trans forming pathways. PMID:25944917

  17. Effect of diallyl disulfide on acute gastric mucosal damage induced by alcohol in rats.

    PubMed

    Lee, I-C; Baek, H-S; Kim, S-H; Moon, C; Park, S-H; Kim, S-H; Shin, I-S; Park, S-C; Kim, J-C

    2015-03-01

    This study investigated the gastroprotective effects of diallyl disulfide (DADS), a secondary organosulfur compound derived from garlic (Allium sativum L.) on experimental model of ethanol (EtOH)-induced gastric ulcer in rats. The antiulcerogenic activity of DADS was evaluated by gross/histopathological inspection, pro-inflammatory cytokines, and lipid peroxidation with antioxidant enzyme activities in the stomach. DADS (100 mg/kg) was administered by oral gavage 2 h prior to EtOH treatment (5 ml/kg). The animals were killed 1 h after receiving EtOH treatment. Pretreatment with DADS attenuated EtOH-induced gastric mucosal injury, as evidenced by decreased severity of hemorrhagic lesions and gastric ulcer index upon visual inspection. DADS also prevented histopathological alterations and gastric apoptotic changes caused by EtOH. An increase in tumor necrosis factor-α (TNF-α) and inducible nitric oxide synthase was observed in the gastric tissues of EtOH-treated rats that coincided with increased serum TNF-α and interleukin 6 levels. In contrast, DADS effectively suppressed production of pro-inflammatory mediators induced by EtOH. Furthermore, DADS prevented the formation of gastric malondialdehyde and the depletion of reduced glutathione content and restored antioxidant enzyme activities, such as catalase, glutathione peroxidase, and glutathione reductase in the gastric tissues of EtOH-treated rats. These results indicate that DADS prevents gastric mucosal damage induced by acute EtOH administration in rats and that the protective effects of DADS may be due to its potent antioxidant and anti-inflammatory activities. PMID:24972622

  18. E2F1 and E2F2 induction in response to DNA damage preserves genomic stability in neuronal cells

    PubMed Central

    Castillo, Daniela S; Campalans, Anna; Belluscio, Laura M; Carcagno, Abel L; Radicella, J Pablo; Cánepa, Eduardo T; Pregi, Nicolás

    2015-01-01

    E2F transcription factors regulate a wide range of biological processes, including the cellular response to DNA damage. In the present study, we examined whether E2F family members are transcriptionally induced following treatment with several genotoxic agents, and have a role on the cell DNA damage response. We show a novel mechanism, conserved among diverse species, in which E2F1 and E2F2, the latter specifically in neuronal cells, are transcriptionally induced after DNA damage. This upregulation leads to increased E2F1 and E2F2 protein levels as a consequence of de novo protein synthesis. Ectopic expression of these E2Fs in neuronal cells reduces the level of DNA damage following genotoxic treatment, while ablation of E2F1 and E2F2 leads to the accumulation of DNA lesions and increased apoptotic response. Cell viability and DNA repair capability in response to DNA damage induction are also reduced by the E2F1 and E2F2 deficiencies. Finally, E2F1 and E2F2 accumulate at sites of oxidative and UV-induced DNA damage, and interact with γH2AX DNA repair factor. As previously reported for E2F1, E2F2 promotes Rad51 foci formation, interacts with GCN5 acetyltransferase and induces histone acetylation following genotoxic insult. The results presented here unveil a new mechanism involving E2F1 and E2F2 in the maintenance of genomic stability in response to DNA damage in neuronal cells. PMID:25892555

  19. E2F1 and E2F2 induction in response to DNA damage preserves genomic stability in neuronal cells.

    PubMed

    Castillo, Daniela S; Campalans, Anna; Belluscio, Laura M; Carcagno, Abel L; Radicella, J Pablo; Cánepa, Eduardo T; Pregi, Nicolás

    2015-01-01

    E2F transcription factors regulate a wide range of biological processes, including the cellular response to DNA damage. In the present study, we examined whether E2F family members are transcriptionally induced following treatment with several genotoxic agents, and have a role on the cell DNA damage response. We show a novel mechanism, conserved among diverse species, in which E2F1 and E2F2, the latter specifically in neuronal cells, are transcriptionally induced after DNA damage. This upregulation leads to increased E2F1 and E2F2 protein levels as a consequence of de novo protein synthesis. Ectopic expression of these E2Fs in neuronal cells reduces the level of DNA damage following genotoxic treatment, while ablation of E2F1 and E2F2 leads to the accumulation of DNA lesions and increased apoptotic response. Cell viability and DNA repair capability in response to DNA damage induction are also reduced by the E2F1 and E2F2 deficiencies. Finally, E2F1 and E2F2 accumulate at sites of oxidative and UV-induced DNA damage, and interact with γH2AX DNA repair factor. As previously reported for E2F1, E2F2 promotes Rad51 foci formation, interacts with GCN5 acetyltransferase and induces histone acetylation following genotoxic insult. The results presented here unveil a new mechanism involving E2F1 and E2F2 in the maintenance of genomic stability in response to DNA damage in neuronal cells. PMID:25892555

  20. Intrinsic excitability changes induced by acute treatment of hippocampal CA1 pyramidal neurons with exogenous amyloid β peptide.

    PubMed

    Tamagnini, Francesco; Scullion, Sarah; Brown, Jon T; Randall, Andrew D

    2015-07-01

    Accumulation of beta-amyloid (Aβ) peptides in the human brain is a canonical pathological hallmark of Alzheimer's disease (AD). Recent work in Aβ-overexpressing transgenic mice indicates that increased brain Aβ levels can be associated with aberrant epileptiform activity. In line with this, such mice can also exhibit altered intrinsic excitability (IE) of cortical and hippocampal neurons: these observations may relate to the increased prevalence of seizures in AD patients. In this study, we examined what changes in IE are produced in hippocampal CA1 pyramidal cells after 2-5 h treatment with an oligomeric preparation of synthetic human Aβ 1-42 peptide. Whole cell current clamp recordings were compared between Aβ-(500 nM) and vehicle-(DMSO 0.05%) treated hippocampal slices obtained from mice. The soluble Aβ treatment did not produce alterations in sub-threshold intrinsic properties, including membrane potential, input resistance, and hyperpolarization activated "sag". Similarly, no changes were noted in the firing profile evoked by 500 ms square current supra-threshold stimuli. However, Aβ 500 nM treatment resulted in the hyperpolarization of the action potential (AP) threshold. In addition, treatment with Aβ at 500 nM depressed the after-hyperpolarization that followed both a single AP or 50 Hz trains of a number of APs between 5 and 25. These data suggest that acute exposure to soluble Aβ oligomers affects IE properties of CA1 pyramidal neurons differently from outcomes seen in transgenic models of amyloidopathy. However, in both chronic and acute models, the IE changes are toward hyperexcitability, reinforcing the idea that amyloidopathy and increased incidence in seizures might be causally related in AD patients. PMID:25515596

  1. Intrinsic excitability changes induced by acute treatment of hippocampal CA1 pyramidal neurons with exogenous amyloid β peptide

    PubMed Central

    Scullion, Sarah; Brown, Jon T.; Randall, Andrew D.

    2015-01-01

    ABSTRACT Accumulation of beta‐amyloid (Aβ) peptides in the human brain is a canonical pathological hallmark of Alzheimer's disease (AD). Recent work in Aβ‐overexpressing transgenic mice indicates that increased brain Aβ levels can be associated with aberrant epileptiform activity. In line with this, such mice can also exhibit altered intrinsic excitability (IE) of cortical and hippocampal neurons: these observations may relate to the increased prevalence of seizures in AD patients. In this study, we examined what changes in IE are produced in hippocampal CA1 pyramidal cells after 2–5 h treatment with an oligomeric preparation of synthetic human Aβ 1–42 peptide. Whole cell current clamp recordings were compared between Aβ‐(500 nM) and vehicle‐(DMSO 0.05%) treated hippocampal slices obtained from mice. The soluble Aβ treatment did not produce alterations in sub‐threshold intrinsic properties, including membrane potential, input resistance, and hyperpolarization activated “sag”. Similarly, no changes were noted in the firing profile evoked by 500 ms square current supra‐threshold stimuli. However, Aβ 500 nM treatment resulted in the hyperpolarization of the action potential (AP) threshold. In addition, treatment with Aβ at 500 nM depressed the after‐hyperpolarization that followed both a single AP or 50 Hz trains of a number of APs between 5 and 25. These data suggest that acute exposure to soluble Aβ oligomers affects IE properties of CA1 pyramidal neurons differently from outcomes seen in transgenic models of amyloidopathy. However, in both chronic and acute models, the IE changes are toward hyperexcitability, reinforcing the idea that amyloidopathy and increased incidence in seizures might be causally related in AD patients. © 2014 The Authors Hippocampus Published by Wiley Periodicals, Inc. PMID:25515596

  2. Ablation of huntingtin in adult neurons is nondeleterious but its depletion in young mice causes acute pancreatitis.

    PubMed

    Wang, Guohao; Liu, Xudong; Gaertig, Marta A; Li, Shihua; Li, Xiao-Jiang

    2016-03-22

    The Huntington's disease (HD) protein, huntingtin (HTT), is essential for early development. Because suppressing the expression of mutantHTTis an important approach to treat the disease, we must first understand the normal function of Htt in adults versus younger animals. Using inducibleHttknockout mice, we found thatHttdepletion does not lead to adult neurodegeneration or animal death at >4 mo of age, which was also verified by selectively depletingHttin neurons. On the other hand, young Htt KO mice die at 2 mo of age of acute pancreatitis due to the degeneration of pancreatic acinar cells. Importantly, Htt interacts with the trypsin inhibitor, serine protease inhibitor Kazal-type 3 (Spink3), to inhibit activation of digestive enzymes in acinar cells in young mice, and transgenicHTTcan rescue the early death of Htt KO mice. These findings point out age- and cell type-dependent vital functions of Htt and the safety of knocking down neuronal Htt expression in adult brains as a treatment. PMID:26951659

  3. Prevention of acute/severe hypoglycemia-induced neuron death by lactate administration.

    PubMed

    Won, Seok Joon; Jang, Bong Geom; Yoo, Byung Hoon; Sohn, Min; Lee, Min Woo; Choi, Bo Young; Kim, Jin Hee; Song, Hong Ki; Suh, Sang Won

    2012-06-01

    Hypoglycemia-induced cerebral neuropathy can occur in patients with diabetes who attempt tight control of blood glucose and may lead to cognitive dysfunction. Accumulating evidence from animal models suggests that hypoglycemia-induced neuronal death is not a simple result of glucose deprivation, but is instead the end result of a multifactorial process. In particular, the excessive activation of poly (ADP-ribose) polymerase-1 (PARP-1) consumes cytosolic nicotinamide adenine dinucleotide (NAD(+)), resulting in energy failure. In this study, we investigate whether lactate administration in the absence of cytosolic NAD(+) affords neuroprotection against hypoglycemia-induced neuronal death. Intraperitoneal injection of sodium L-lactate corrected arterial blood pH and blood lactate concentration after hypoglycemia. Lactate administered without glucose was not sufficient to promote electroencephalogram recovery from an isoelectric state during hypoglycemia. However, supplementation of glucose with lactate reduced neuronal death by ∼80% in the hippocampus. Hypoglycemia-induced superoxide production and microglia activation was also substantially reduced by administration of lactate. Taken together, these results suggest an intriguing possibility: that increasing brain lactate following hypoglycemia offsets the decrease in NAD(+) due to overactivation of PARP-1 by acting as an alternative energy substrate that can effectively bypass glycolysis and be fed directly to the citric acid cycle to maintain cellular ATP levels. PMID:22453629

  4. Alterations in neuronal morphology in infralimbic cortex predict resistance to fear extinction following acute stress

    PubMed Central

    Moench, Kelly M.; Maroun, Mouna; Kavushansky, Alexandra; Wellman, Cara

    2015-01-01

    Dysfunction in corticolimbic circuits that mediate the extinction of learned fear responses is thought to underlie the perseveration of fear in stress-related psychopathologies, including post-traumatic stress disorder. Chronic stress produces dendritic hypertrophy in basolateral amygdala (BLA) and dendritic hypotrophy in medial prefrontal cortex, whereas acute stress leads to hypotrophy in both BLA and prelimbic cortex. Additionally, both chronic and acute stress impair extinction retrieval. Here, we examined the effects of a single elevated platform stress on extinction learning and dendritic morphology in infralimbic cortex, a region considered to be critical for extinction. Acute stress produced resistance to extinction, as well as dendritic retraction in infralimbic cortex. Spine density on apical and basilar terminal branches was unaffected by stress. However, animals that underwent conditioning and extinction had decreased spine density on apical terminal branches. Thus, whereas dendritic morphology in infralimbic cortex appears to be particularly sensitive to stress, changes in spines may more sensitively reflect learning. Further, in stressed rats that underwent conditioning and extinction, the level of extinction learning was correlated with spine densities, in that rats with poorer extinction retrieval had more immature spines and fewer thin spines than rats with better extinction retrieval, suggesting that stress may have impaired learning-related spine plasticity. These results may have implications for understanding the role of medial prefrontal cortex in learning deficits associated with stress-related pathologies. PMID:26844245

  5. Alterations in neuronal morphology in infralimbic cortex predict resistance to fear extinction following acute stress.

    PubMed

    Moench, Kelly M; Maroun, Mouna; Kavushansky, Alexandra; Wellman, Cara

    2016-06-01

    Dysfunction in corticolimbic circuits that mediate the extinction of learned fear responses is thought to underlie the perseveration of fear in stress-related psychopathologies, including post-traumatic stress disorder. Chronic stress produces dendritic hypertrophy in basolateral amygdala (BLA) and dendritic hypotrophy in medial prefrontal cortex, whereas acute stress leads to hypotrophy in both BLA and prelimbic cortex. Additionally, both chronic and acute stress impair extinction retrieval. Here, we examined the effects of a single elevated platform stress on extinction learning and dendritic morphology in infralimbic cortex, a region considered to be critical for extinction. Acute stress produced resistance to extinction, as well as dendritic retraction in infralimbic cortex. Spine density on apical and basilar terminal branches was unaffected by stress. However, animals that underwent conditioning and extinction had decreased spine density on apical terminal branches. Thus, whereas dendritic morphology in infralimbic cortex appears to be particularly sensitive to stress, changes in spines may more sensitively reflect learning. Further, in stressed rats that underwent conditioning and extinction, the level of extinction learning was correlated with spine densities, in that rats with poorer extinction retrieval had more immature spines and fewer thin spines than rats with better extinction retrieval, suggesting that stress may have impaired learning-related spine plasticity. These results may have implications for understanding the role of medial prefrontal cortex in learning deficits associated with stress-related pathologies. PMID:26844245

  6. Bone marrow-derived mesenchymal stem cells improve diabetes-induced cognitive impairment by exosome transfer into damaged neurons and astrocytes

    PubMed Central

    Nakano, Masako; Nagaishi, Kanna; Konari, Naoto; Saito, Yuki; Chikenji, Takako; Mizue, Yuka; Fujimiya, Mineko

    2016-01-01

    The incidence of dementia is higher in diabetic patients, but no effective treatment has been developed. This study showed that rat bone marrow mesenchymal stem cells (BM-MSCs) can improve the cognitive impairments of STZ-diabetic mice by repairing damaged neurons and astrocytes. The Morris water maze test demonstrated that cognitive impairments induced by diabetes were significantly improved by intravenous injection of BM-MSCs. In the CA1 region of the hippocampus, degeneration of neurons and astrocytes, as well as synaptic loss, were prominent in diabetes, and BM-MSC treatment successfully normalized them. Since a limited number of donor BM-MSCs was observed in the brain parenchyma, we hypothesized that humoral factors, especially exosomes released from BM-MSCs, act on damaged neurons and astrocytes. To investigate the effectiveness of exosomes for treatment of diabetes-induced cognitive impairment, exosomes were purified from the culture media and injected intracerebroventricularly into diabetic mice. Recovery of cognitive impairment and histological abnormalities similar to that seen with BM-MSC injection was found following exosome treatment. Use of fluorescence-labeled exosomes demonstrated that injected exosomes were internalized into astrocytes and neurons; these subsequently reversed the dysfunction. The present results indicate that exosomes derived from BM-MSCs might be a promising therapeutic tool for diabetes-induced cognitive impairment. PMID:27102354

  7. Bone marrow-derived mesenchymal stem cells improve diabetes-induced cognitive impairment by exosome transfer into damaged neurons and astrocytes.

    PubMed

    Nakano, Masako; Nagaishi, Kanna; Konari, Naoto; Saito, Yuki; Chikenji, Takako; Mizue, Yuka; Fujimiya, Mineko

    2016-01-01

    The incidence of dementia is higher in diabetic patients, but no effective treatment has been developed. This study showed that rat bone marrow mesenchymal stem cells (BM-MSCs) can improve the cognitive impairments of STZ-diabetic mice by repairing damaged neurons and astrocytes. The Morris water maze test demonstrated that cognitive impairments induced by diabetes were significantly improved by intravenous injection of BM-MSCs. In the CA1 region of the hippocampus, degeneration of neurons and astrocytes, as well as synaptic loss, were prominent in diabetes, and BM-MSC treatment successfully normalized them. Since a limited number of donor BM-MSCs was observed in the brain parenchyma, we hypothesized that humoral factors, especially exosomes released from BM-MSCs, act on damaged neurons and astrocytes. To investigate the effectiveness of exosomes for treatment of diabetes-induced cognitive impairment, exosomes were purified from the culture media and injected intracerebroventricularly into diabetic mice. Recovery of cognitive impairment and histological abnormalities similar to that seen with BM-MSC injection was found following exosome treatment. Use of fluorescence-labeled exosomes demonstrated that injected exosomes were internalized into astrocytes and neurons; these subsequently reversed the dysfunction. The present results indicate that exosomes derived from BM-MSCs might be a promising therapeutic tool for diabetes-induced cognitive impairment. PMID:27102354

  8. Differential protection of black-seed oil on econucleotidase, cholinesterases and aminergic catabolizing enzyme in haloperidol-induced neuronal damage of male rats

    PubMed Central

    Akintunde, Jacob K.; Irechukwu, C. Abigail

    2016-01-01

    Background: The antipsychotic, haloperidol, is extremely efficient in the treatment of schizophrenia but its application is constrained because of irreversible adverse drug reactions. Hence, in this study, we investigate the differential effects of black seed oil on cholinesterase [acetylcholinesterase (AChE) and butrylcholinesterase (BuChE), ectonucleotidase (5′-nucleotidase), lactate dehydrogenase (LDH) and monoamine oxidase (MAO)] activities and relevant markers of oxidative stress in the cerebrum of haloperidol-induced neuronal-damaged rats. Methods: The animals were divided into six groups (n = 10): normal control rats; haloperidol-induced rats: induced rats were pre-, co- and post-treated with black-seed oil respectively, while the last group was treated with extract oil only. The treatment was performed via oral administration and the experiment lasted 14 days. Results: The results revealed an increase in 5I nucleotidase, a marker of adenosine triphosphate (ATP) and adenosine monophosphate (AMP) hydrolysis, as well as AChE, BuChE and MAO activities, with concomitant decrease in LDH activity of cerebrum in induced rats when compared with controls. Also, administration of haloperidol caused systemic oxidative damage and adverse histopathological changes in neuronal cells, indications of mental disorder. The differential treatments with black-seed oil prevented these alterations by increasing LDH and decreasing 5I nucleotidase, AChE, BuChE and MAO activities in the cerebrum. Essential oil post-treatment is most efficacious in reversing haloperidol-induced neuronal damage in rat; followed by pre- and cotreatment, respectively. Conclusions: We concluded that essential black-seed oil enhanced the wellness of aminergic, purinergic and cholinergic neurotransmissions of haloperidol-induced neuronal damage in rats. PMID:27493717

  9. Acute and chronic complications of laser angioplasty: vascular wall damage and formation of aneurysms in the atherosclerotic rabbit.

    PubMed

    Lee, G; Ikeda, R M; Theis, J H; Chan, M C; Stobbe, D; Ogata, C; Kumagai, A; Mason, D T

    1984-01-15

    Acute and chronic vascular responses to laser exposure in atherosclerotic rabbits were studied. In 7 rabbits fed an atherogenic diet for 3 to 5 months before the study to induce aortic atherosclerosis, a flexible quartz fiber, 400 micron core diameter, attached to an argon ion laser was passed anterogradely or retrogradely to the atherosclerotic ascending aorta. The laser was turned on using power intensities of 1 to 2 W for 3 seconds. After laser treatment, the aortas were studied acutely in 3 rabbits and chronically in 4 rabbits after recovery for 1 to 14 days. In 2 rabbits studied acutely, the argon laser produced a vaporized crater within the atherosclerotic plaque at the endothelial surface; however, in 1 there was also vascular damage extending deep into the medial layer. In addition, aortic aneurysm with muscular wall damage occurred in 2 of the 4 animals studied chronically. Thus, vascular complications may arise when catheter laser angioplasty is randomly applied without visualizing specific plaque targets or without using safe dose increments of power intensities and durations of exposure. This study suggests caution in the clinical use of intensive phototherapy to cardiovascular lesions and stresses the need for further understanding of laser vascular consequences before application of laser angioplasty in patients. PMID:6695725

  10. Translational profiling identifies a cascade of damage initiated in motor neurons and spreading to glia in mutant SOD1-mediated ALS

    PubMed Central

    Sun, Shuying; Sun, Ying; Ling, Shuo-Chien; Ferraiuolo, Laura; McAlonis-Downes, Melissa; Zou, Yiyang; Drenner, Kevin; Wang, Yin; Ditsworth, Dara; Tokunaga, Seiya; Kopelevich, Alex; Kaspar, Brian K.; Lagier-Tourenne, Clotilde; Cleveland, Don W.

    2015-01-01

    Ubiquitous expression of amyotrophic lateral sclerosis (ALS)-causing mutations in superoxide dismutase 1 (SOD1) provokes noncell autonomous paralytic disease. By combining ribosome affinity purification and high-throughput sequencing, a cascade of mutant SOD1-dependent, cell type-specific changes are now identified. Initial mutant-dependent damage is restricted to motor neurons and includes synapse and metabolic abnormalities, endoplasmic reticulum (ER) stress, and selective activation of the PRKR-like ER kinase (PERK) arm of the unfolded protein response. PERK activation correlates with what we identify as a naturally low level of ER chaperones in motor neurons. Early changes in astrocytes occur in genes that are involved in inflammation and metabolism and are targets of the peroxisome proliferator-activated receptor and liver X receptor transcription factors. Dysregulation of myelination and lipid signaling pathways and activation of ETS transcription factors occur in oligodendrocytes only after disease initiation. Thus, pathogenesis involves a temporal cascade of cell type-selective damage initiating in motor neurons, with subsequent damage within glia driving disease propagation. PMID:26621731

  11. N-methyl-D-aspartate receptor-mediated mitochondrial Ca(2+) overload in acute excitotoxic motor neuron death: a mechanism distinct from chronic neurotoxicity after Ca(2+) influx.

    PubMed

    Urushitani, M; Nakamizo, T; Inoue, R; Sawada, H; Kihara, T; Honda, K; Akaike, A; Shimohama, S

    2001-03-01

    Mitochondrial uptake of Ca(2+) has recently been found to play an important role in glutamate-induced neurotoxicity (GNT) as well as in the activation of Ca(2+)-dependent molecules, such as calmodulin and neuronal nitric oxide synthase (nNOS), in the cytoplasm. Prolonged exposure to glutamate injures motor neurons predominantly through the activation of Ca(2+)/calmodulin-nNOS, as previously reported, and is, in part, associated with the pathogenesis of amyotrophic lateral sclerosis (ALS). In the present study, we investigated how mitochondrial uptake of Ca(2+) is involved in GNT in spinal motor neurons. Acute excitotoxicity induced by exposure to 0.5 mM glutamate for 5 min was found in both motor and nonmotor neurons in cultured spinal cords from rat embryos and was dependent on extracellular Ca(2+) and on N-methyl-D-aspartate (NMDA) receptor activation. Mitochondrial uncouplers markedly blocked acute excitotoxicity, and membrane-permeable superoxide dismutase mimics attenuated acute excitotoxicity induced by glutamate and NMDA but not by alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) or kainate. Fluorimetric analysis showed that mitochondrial Ca(2+) was elevated promptly with subsequent accumulation of reactive oxygen species (ROS) in the mitochondria. An NMDA receptor antagonist and a mitochondrial uncoupler eliminated the increase in fluorescence of mitochondrial Ca(2+) and ROS indicators. These data indicate that acute excitotoxicity in spinal neurons is mediated by mitochondrial Ca(2+) overload and ROS generation through the activation of NMDA receptors. This mechanism is different from that of chronic GNT. PMID:11223912

  12. Hydrogen sulfide prevents ethanol-induced gastric damage in mice: role of ATP-sensitive potassium channels and capsaicin-sensitive primary afferent neurons.

    PubMed

    Medeiros, Jand Venes R; Bezerra, Víctor H; Gomes, Antoniella S; Barbosa, André Luiz R; Lima-Júnior, Roberto César P; Soares, Pedro Marcos G; Brito, Gerly Anne C; Ribeiro, Ronaldo A; Cunha, Fernando Q; Souza, Marcellus H L P

    2009-09-01

    The aim of this study was to evaluate the protective effect of hydrogen sulfide (H(2)S) on ethanol-induced gastric lesions in mice and the influence of ATP-sensitive potassium (K(ATP)) channels, capsaicin-sensitive sensory afferent neurons, and transient receptor potential vanilloid (TRPV) 1 receptors on such an effect. Saline and L-cysteine alone or with propargylglycine, sodium hydrogen sulfide (NaHS), or Lawesson's reagent were administrated for testing purposes. For other experiments, mice were pretreated with glibenclamide, neurotoxic doses of capsaicin, or capsazepine. Afterward, mice received L-cysteine, NaHS, or Lawesson's reagent. After 30 min, 50% ethanol was administrated by gavage. After 1 h, mice were sacrificed, and gastric damage was evaluated by macroscopic and microscopic analyses. L-cysteine, NaHS, and Lawesson's reagent treatment prevented ethanol-induced macroscopic and microscopic gastric damage in a dose-dependent manner. Administration of propargylglycine, an inhibitor of endogenous H(2)S synthesis, reversed gastric protection induced by L-cysteine. Glibenclamide reversed L-cysteine, NaHS, or Lawesson's reagent gastroprotective effects against ethanol-induced macroscopic damage in a dose-dependent manner. Chemical ablation of sensory afferent neurons by capsaicin reversed gastroprotective effects of L-cysteine or H(2)S donors (NaHS or Lawesson's reagent) in ethanol-induced macroscopic gastric damage. Likewise, in the presence of the TRPV1 antagonist capsazepine, the gastroprotective effects of L-cysteine, NaHS, or Lawesson's reagent were also abolished. Our results suggest that H(2)S prevents ethanol-induced gastric damage. Although there are many mechanisms through which this effect can occur, our data support the hypothesis that the activation of K(ATP) channels and afferent neurons/TRPV1 receptors is of primary importance. PMID:19491326

  13. Redox-Dependent Modulation of T-Type Ca2+ Channels in Sensory Neurons Contributes to Acute Anti-Nociceptive Effect of Substance P

    PubMed Central

    Huang, Dongyang; Huang, Sha; Gao, Haixia; Liu, Yani; Qi, Jinlong; Chen, Pingping; Wang, Caixue; Scragg, Jason L.; Vakurov, Alexander; Peers, Chris; Du, Xiaona

    2016-01-01

    Abstract Aims: Neuropeptide substance P (SP) is produced and released by a subset of peripheral sensory neurons that respond to tissue damage (nociceptors). SP exerts excitatory effects in the central nervous system, but peripheral SP actions are still poorly understood; therefore, here, we aimed at investigating these peripheral mechanisms. Results: SP acutely inhibited T-type voltage-gated Ca2+ channels in nociceptors. The effect was mediated by neurokinin 1 (NK1) receptor-induced stimulation of intracellular release of reactive oxygen species (ROS), as it can be prevented or reversed by the reducing agent dithiothreitol and mimicked by exogenous or endogenous ROS. This redox-mediated T-type Ca2+ channel inhibition operated through the modulation of CaV3.2 channel sensitivity to ambient zinc, as it can be prevented or reversed by zinc chelation and mimicked by exogenous zinc. Elimination of the zinc-binding site in CaV3.2 rendered the channel insensitive to SP-mediated inhibition. Importantly, peripherally applied SP significantly reduced bradykinin-induced nociception in rats in vivo; knock-down of CaV3.2 significantly reduced this anti-nociceptive effect. This atypical signaling cascade shared the initial steps with the SP-mediated augmentation of M-type K+ channels described earlier. Innovation: Our study established a mechanism underlying the peripheral anti-nociceptive effect of SP whereby this neuropeptide produces ROS-dependent inhibition of pro-algesic T-type Ca2+ current and concurrent enhancement of anti-algesic M-type K+ current. These findings will lead to a better understanding of mechanisms of endogenous analgesia. Conclusion: SP modulates T-type channel activity in nociceptors by a redox-dependent tuning of channel sensitivity to zinc; this novel modulatory pathway contributes to the peripheral anti-nociceptive effect of SP. Antioxid. Redox Signal. 25, 233–251. PMID:27306612

  14. Oxidative stress, inflammation, and DNA damage in multiple organs of mice acutely exposed to amorphous silica nanoparticles

    PubMed Central

    Nemmar, Abderrahim; Yuvaraju, Priya; Beegam, Sumaya; Yasin, Javed; Kazzam, Elsadig E; Ali, Badreldin H

    2016-01-01

    The use of amorphous silica (SiO2) in biopharmaceutical and industrial fields can lead to human exposure by injection, skin penetration, ingestion, or inhalation. However, the in vivo acute toxicity of amorphous SiO2 nanoparticles (SiNPs) on multiple organs and the mechanisms underlying these effects are not well understood. Presently, we investigated the acute (24 hours) effects of intraperitoneally administered 50 nm SiNPs (0.25 mg/kg) on systemic toxicity, oxidative stress, inflammation, and DNA damage in the lung, heart, liver, kidney, and brain of mice. Lipid peroxidation was significantly increased by SiNPs in the lung, liver, kidney, and brain, but was not changed in the heart. Similarly, superoxide dismutase and catalase activities were significantly affected by SiNPs in all organs studied. While the concentration of tumor necrosis factor α was insignificantly increased in the liver and brain, its increase was statistically significant in the lung, heart, and kidney. SiNPs induced a significant elevation in pulmonary and renal interleukin 6 and interleukin-1 beta in the lung, liver, and brain. Moreover, SiNPs caused a significant increase in DNA damage, assessed by comet assay, in all the organs studied. SiNPs caused leukocytosis and increased the plasma activities of lactate dehydrogenase, creatine kinase, alanine aminotranferase, and aspartate aminotransferase. These results indicate that acute systemic exposure to SiNPs causes oxidative stress, inflammation, and DNA damage in several major organs, and highlight the need for thorough evaluation of SiNPs before they can be safely used in human beings. PMID:27022259

  15. Bone marrow mesenchymal stem cell implantation for the treatment of radioactivity‑induced acute skin damage in rats.

    PubMed

    Zheng, Kai; Wu, Weizhen; Yang, Shunliang; Huang, Lianghu; Chen, Jin; Gong, Chungui; Fu, Zhichao; Zhang, Linlin; Tan, Jianming

    2015-11-01

    The present study aimed to observe the role of mesenchymal stem cells (MSCs) in the repair of acute skin damage caused by radiation. Rat bone marrow MSCs (BMSCs) were isolated and cultured in vitro. A rat model of radiation‑induced acute skin damage was established by irradiation of the hind legs of Sprague-Dawley rats using a linear accelerator (45 Gy). After irradiation, rats were randomly divided into two groups: BMSC group and control group. Rats in the BMSC group were treated with a tail vein injection of 2x106 BMSCs (1 ml) immediately after irradiation and a local multipoint injection of 2x106 BMSCs at the injured area two weeks later. Then the wound healing of each rat was observed. The expression of transforming growth factor (TGF)‑β1, stromal cell‑derived factor-1 (SDF‑1) and prostaglandin E2 (PGE2) in the wounded tissues was determined by immunohistochemistry. The results demonstrated that skin damage was milder in the BMSC group than in the control group. Moreover, the speed of healing in the BMSC group was better than that in the control group. In addition, the wound score, it was significantly lower in the BMSC group than in the control group (P<0.05). The expression of PGE2 and TGF‑β1 in the BMSC group was also significantly lower than that in the control group (P<0.05), whereas the SDF‑1 expression was significantly higher in the BMSC group than that in the control group (P<0.05). BMSCs can effectively reduce inflammation and fibrosis in the wounded skin and promote the repair of acute radioactive skin injury. Thus, may be developed as a novel treatment for wound healing. PMID:26323987

  16. Acute and long-term exposure to chlorpyrifos induces cell death of basal forebrain cholinergic neurons through AChE variants alteration.

    PubMed

    del Pino, Javier; Moyano, Paula; Anadon, María José; García, José Manuel; Díaz, María Jesús; García, Jimena; Frejo, María Teresa

    2015-10-01

    Chlorpyrifos (CPF) is one of the most widely used organophosphates insecticides that has been reported to induce cognitive disorders both after acute and repeated administration similar to those induced in Alzheimer's disease (AD). However, the mechanisms through which it induces these effects are unknown. On the other hand, the cholinergic system, mainly basal forebrain cholinergic neurons, is involved in learning and memory regulation, and an alteration of cholinergic transmission or/and cholinergic cell loss could induce these effects. In this regard, it has been reported that CPF can affect cholinergic transmission, and alter AChE variants, which have been shown to be related with basal forebrain cholinergic neuronal loss. According to these data, we hypothesized that CPF could induce basal forebrain cholinergic neuronal loss through cholinergic transmission and AChE variants alteration. To prove this hypothesis, we evaluated in septal SN56 basal forebrain cholinergic neurons, the CPF toxic effects after 24h and 14 days exposure on neuronal viability and the cholinergic mechanisms related to it. This study shows that CPF impaired cholinergic transmission, induced AChE inhibition and, only after long-term exposure, increased CHT expression, which suggests that acetylcholine levels alteration could be mediated by these actions. Moreover, CPF induces, after acute and long-term exposure, cell death in cholinergic neurons in the basal forebrain and this effect is independent of AChE inhibition and acetylcholine alteration, but was mediated partially by AChE variants alteration. Our present results provide a new understanding of the mechanisms contributing to the harmful effects of CPF on neuronal function and viability, and the possible relevance of CPF in the pathogenesis of neurodegenerative diseases. PMID:26210949

  17. Sprouty2 and ‐4 hypomorphism promotes neuronal survival and astrocytosis in a mouse model of kainic acid induced neuronal damage

    PubMed Central

    Thongrong, Sitthisak; Hausott, Barbara; Marvaldi, Letizia; Agostinho, Alexandra S.; Zangrandi, Luca; Burtscher, Johannes; Fogli, Barbara

    2015-01-01

    ABSTRACT Sprouty (Spry) proteins play a key role as negative feedback inhibitors of the Ras/Raf/MAPK/ERK pathway downstream of various receptor tyrosine kinases. Among the four Sprouty isoforms, Spry2 and Spry4 are expressed in the hippocampus. In this study, possible effects of Spry2 and Spry4 hypomorphism on neurodegeneration and seizure thresholds in a mouse model of epileptogenesis was analyzed. The Spry2/4 hypomorphs exhibited stronger ERK activation which was limited to the CA3 pyramidal cell layer and to the hilar region. The seizure threshold of Spry2/4+/− mice was significantly reduced at naive state but no difference to wildtype mice was observed 1 month following KA treatment. Histomorphological analysis revealed that dentate granule cell dispersion (GCD) was diminished in Spry2/4+/− mice in the subchronic phase after KA injection. Neuronal degeneration was reduced in CA1 and CA3 principal neuron layers as well as in scattered neurons of the contralateral CA1 and hilar regions. Moreover, Spry2/4 reduction resulted in enhanced survival of somatostatin and neuropeptide Y expressing interneurons. GFAP staining intensity and number of reactive astrocytes markedly increased in lesioned areas of Spry2/4+/− mice as compared with wildtype mice. Taken together, although the seizure threshold is reduced in naive Spry2/4+/− mice, neurodegeneration and GCD is mitigated following KA induced hippocampal lesions, identifying Spry proteins as possible pharmacological targets in brain injuries resulting in neurodegeneration. The present data are consistent with the established functions of the ERK pathway in astrocyte proliferation as well as protection from neuronal cell death and suggest a novel role of Spry proteins in the migration of differentiated neurons. © 2015 The Authors Hippocampus Published by Wiley Periodicals, Inc. PMID:26540287

  18. A microfluidic device to study neuronal and motor responses to acute chemical stimuli in zebrafish

    PubMed Central

    Candelier, Raphaël; Sriti Murmu, Meena; Alejo Romano, Sebastián; Jouary, Adrien; Debrégeas, Georges; Sumbre, Germán

    2015-01-01

    Zebrafish larva is a unique model for whole-brain functional imaging and to study sensory-motor integration in the vertebrate brain. To take full advantage of this system, one needs to design sensory environments that can mimic the complex spatiotemporal stimulus patterns experienced by the animal in natural conditions. We report on a novel open-ended microfluidic device that delivers pulses of chemical stimuli to agarose-restrained larvae with near-millisecond switching rate and unprecedented spatial and concentration accuracy and reproducibility. In combination with two-photon calcium imaging and recordings of tail movements, we found that stimuli of opposite hedonic values induced different circuit activity patterns. Moreover, by precisely controlling the duration of the stimulus (50–500 ms), we found that the probability of generating a gustatory-induced behavior is encoded by the number of neurons activated. This device may open new ways to dissect the neural-circuit principles underlying chemosensory perception. PMID:26194888

  19. Age-dependent loss of cholinergic neurons in learning and memory-related brain regions and impaired learning in SAMP8 mice with trigeminal nerve damage.

    PubMed

    He, Yifan; Zhu, Jihong; Huang, Fang; Qin, Liu; Fan, Wenguo; He, Hongwen

    2014-11-15

    The tooth belongs to the trigeminal sensory pathway. Dental damage has been associated with impairments in the central nervous system that may be mediated by injury to the trigeminal nerve. In the present study, we investigated the effects of damage to the inferior alveolar nerve, an important peripheral nerve in the trigeminal sensory pathway, on learning and memory behaviors and structural changes in related brain regions, in a mouse model of Alzheimer's disease. Inferior alveolar nerve transection or sham surgery was performed in middle-aged (4-month-old) or elderly (7-month-old) senescence-accelerated mouse prone 8 (SAMP8) mice. When the middle-aged mice reached 8 months (middle-aged group 1) or 11 months (middle-aged group 2), and the elderly group reached 11 months, step-down passive avoidance and Y-maze tests of learning and memory were performed, and the cholinergic system was examined in the hippocampus (Nissl staining and acetylcholinesterase histochemistry) and basal forebrain (choline acetyltransferase immunohistochemistry). In the elderly group, animals that underwent nerve transection had fewer pyramidal neurons in the hippocampal CA1 and CA3 regions, fewer cholinergic fibers in the CA1 and dentate gyrus, and fewer cholinergic neurons in the medial septal nucleus and vertical limb of the diagonal band, compared with sham-operated animals, as well as showing impairments in learning and memory. Conversely, no significant differences in histology or behavior were observed between middle-aged group 1 or group 2 transected mice and age-matched sham-operated mice. The present findings suggest that trigeminal nerve damage in old age, but not middle age, can induce degeneration of the septal-hippocampal cholinergic system and loss of hippocampal pyramidal neurons, and ultimately impair learning ability. Our results highlight the importance of active treatment of trigeminal nerve damage in elderly patients and those with Alzheimer's disease, and indicate that

  20. Age-dependent loss of cholinergic neurons in learning and memory-related brain regions and impaired learning in SAMP8 mice with trigeminal nerve damage

    PubMed Central

    He, Yifan; Zhu, Jihong; Huang, Fang; Qin, Liu; Fan, Wenguo; He, Hongwen

    2014-01-01

    The tooth belongs to the trigeminal sensory pathway. Dental damage has been associated with impairments in the central nervous system that may be mediated by injury to the trigeminal nerve. In the present study, we investigated the effects of damage to the inferior alveolar nerve, an important peripheral nerve in the trigeminal sensory pathway, on learning and memory behaviors and structural changes in related brain regions, in a mouse model of Alzheimer's disease. Inferior alveolar nerve transection or sham surgery was performed in middle-aged (4-month-old) or elderly (7-month-old) senescence-accelerated mouse prone 8 (SAMP8) mice. When the middle-aged mice reached 8 months (middle-aged group 1) or 11 months (middle-aged group 2), and the elderly group reached 11 months, step-down passive avoidance and Y-maze tests of learning and memory were performed, and the cholinergic system was examined in the hippocampus (Nissl staining and acetylcholinesterase histochemistry) and basal forebrain (choline acetyltransferase immunohistochemistry). In the elderly group, animals that underwent nerve transection had fewer pyramidal neurons in the hippocampal CA1 and CA3 regions, fewer cholinergic fibers in the CA1 and dentate gyrus, and fewer cholinergic neurons in the medial septal nucleus and vertical limb of the diagonal band, compared with sham-operated animals, as well as showing impairments in learning and memory. Conversely, no significant differences in histology or behavior were observed between middle-aged group 1 or group 2 transected mice and age-matched sham-operated mice. The present findings suggest that trigeminal nerve damage in old age, but not middle age, can induce degeneration of the septal-hippocampal cholinergic system and loss of hippocampal pyramidal neurons, and ultimately impair learning ability. Our results highlight the importance of active treatment of trigeminal nerve damage in elderly patients and those with Alzheimer's disease, and indicate that

  1. Melanocortin receptor agonist ACTH 1-39 protects rat forebrain neurons from apoptotic, excitotoxic and inflammation-related damage.

    PubMed

    Lisak, Robert P; Nedelkoska, Liljana; Bealmear, Beverly; Benjamins, Joyce A

    2015-11-01

    Patients with relapsing-remitting multiple sclerosis (RRMS) are commonly treated with high doses of intravenous corticosteroids (CS). ACTH 1-39, a member of the melanocortin family, stimulates production of CS by the adrenals, but melanocortin receptors are also found in the central nervous system (CNS) and on immune cells. ACTH is produced within the CNS and may have direct protective effects on glia and neurons independent of CS. We previously reported that ACTH 1-39 protected oligodendroglia (OL) and their progenitors (OPC) from a panel of excitotoxic and inflammation-related agents. Neurons are the most vulnerable cells in the CNS. They are terminally differentiated, and sensitive to inflammatory and excitotoxic insults. For potential therapeutic protection of gray matter, it is important to investigate the direct effects of ACTH on neurons. Cultures highly enriched in neurons were isolated from 2-3 day old rat brain. After 4-7 days in culture, the neurons were treated for 24h with selected toxic agents with or without ACTH 1-39. ACTH 1-39 protected neurons from death induced by staurosporine, glutamate, NMDA, AMPA, kainate, quinolinic acid, reactive oxygen species and, to a modest extent, from rapidly released NO, but did not protect against kynurenic acid or slowly released nitric oxide. Our results show that ACTH 1-39 protects neurons in vitro from several apoptotic, excitotoxic and inflammation-related insults. PMID:26300474

  2. Optical recording of fast neuronal membrane potential transients in acute mammalian brain slices by second-harmonic generation microscopy.

    PubMed

    Dombeck, Daniel A; Sacconi, Leonardo; Blanchard-Desce, Mireille; Webb, Watt W

    2005-11-01

    Although nonlinear microscopy and fast (approximately 1 ms) membrane potential (Vm) recording have proven valuable for neuroscience applications, their potentially powerful combination has not yet been shown for studies of Vm activity deep in intact tissue. We show that laser illumination of neurons in acute rat brain slices intracellularly filled with FM4-64 dye generates an intense second-harmonic generation (SHG) signal from somatic and dendritic plasma membranes with high contrast >125 microm below the slice surface. The SHG signal provides a linear response to DeltaVm of approximately 7.5%/100 mV. By averaging repeated line scans (approximately 50), we show the ability to record action potentials (APs) optically with a signal-to-noise ratio (S/N) of approximately 7-8. We also show recording of fast Vm steps from the dendritic arbor at depths inaccessible with previous methods. The high membrane contrast and linear response of SHG to DeltaVm provides the advantage that signal changes are not degraded by background and can be directly quantified in terms of DeltaVm. Experimental comparison of SHG and two-photon fluorescence Vm recording with the best known probes for each showed that the SHG technique is superior for Vm recording in brain slice applications, with FM4-64 as the best tested SHG Vm probe. PMID:16093337

  3. Pharmacological Inhibition of Transforming Growth Factor β Signaling Decreases Infection and Prevents Heart Damage in Acute Chagas' Disease▿

    PubMed Central

    Waghabi, Mariana C.; de Souza, Elen M.; de Oliveira, Gabriel M.; Keramidas, Michelle; Feige, Jean-Jacques; Araújo-Jorge, Tania C.; Bailly, Sabine

    2009-01-01

    Chagas' disease induced by Trypanosoma cruzi infection is an important cause of mortality and morbidity affecting the cardiovascular system for which presently available therapies are largely inadequate. We previously reported that transforming growth factor β (TGF-β) is implicated in several regulatory aspects of T. cruzi invasion and growth and in host tissue fibrosis. This prompted us to evaluate the therapeutic action of an inhibitor of TGF-β signaling (SB-431542) administered during the acute phase of experimental Chagas' disease. Male Swiss mice were infected intraperitoneally with 104 trypomastigotes of T. cruzi (Y strain) and evaluated clinically for the following 30 days. SB-431542 treatment significantly reduced mortality and decreased parasitemia. Electrocardiography showed that SB-431542 treatment was effective in protecting the cardiac conduction system. By 14 day postinfection, enzymatic biomarkers of tissue damage indicated that muscle injury was decreased by SB-431542 treatment, with significantly lower blood levels of aspartate aminotransferase and creatine kinase. In conclusion, inhibition of TGF-β signaling in vivo appears to potently decrease T. cruzi infection and to prevent heart damage in a preclinical mouse model. This suggests that this class of molecules may represent a new therapeutic agent for acute and chronic Chagas' disease that warrants further clinical exploration. PMID:19738024

  4. Inhibition of pancreatic oxidative damage by stilbene derivative dihydro-resveratrol: implication for treatment of acute pancreatitis

    PubMed Central

    Tsang, Siu Wai; Guan, Yi-Fu; Wang, Juan; Bian, Zhao-Xiang; Zhang, Hong-Jie

    2016-01-01

    Trans-resveratrol is a natural stilbenoid possessing multifarious pharmacological benefits; however, when orally consumed, it is rapidly metabolised by colonic microflora and converted to dihydro-resveratrol. Thus, this microbial metabolite is of great therapeutic relevance. In the present study, upon the oral administration of dihydro-resveratrol (10–50 mg/kg), the severity of acute pancreatitis in the cerulein-treated rats was significantly ameliorated as evidenced by decreased α-amylase activities in the plasma and lessened oedema formation in the pancreatic parenchyma. In addition, the generation of intracellular reactive oxidative products, including malondialdehyde and protein carbonyls, was accordingly reduced, so as the production of pro-inflammatory cytokines. While inhibiting the activities of NADPH oxidase and myeloperoxidase, the depletion of glutathione was considerably restored. Importantly, the attenuation of pancreatic oxidative damage by dihydro-resveratrol was associated with a down-regulation of the nuclear factor-kappaB and phosphatidylinositol 3′-kinase-serine/threonine kinase signalling pathways. Furthermore, we demonstrated that the solubility of dihydro-resveratrol was at least 5 times higher than trans-resveratrol whilst exhibiting a much lower cytotoxicity. Collectively, the current findings accentuate new mechanistic insight of dihydro-resveratrol in pancreatic oxidative damage, and advocate its therapeutic potential for the management of acute pancreatitis, particularly for patients unresponsive to trans-resveratrol due to the lack of proper microbial strains. PMID:26971398

  5. Inhibition of pancreatic oxidative damage by stilbene derivative dihydro-resveratrol: implication for treatment of acute pancreatitis.

    PubMed

    Tsang, Siu Wai; Guan, Yi-Fu; Wang, Juan; Bian, Zhao-Xiang; Zhang, Hong-Jie

    2016-01-01

    Trans-resveratrol is a natural stilbenoid possessing multifarious pharmacological benefits; however, when orally consumed, it is rapidly metabolised by colonic microflora and converted to dihydro-resveratrol. Thus, this microbial metabolite is of great therapeutic relevance. In the present study, upon the oral administration of dihydro-resveratrol (10-50 mg/kg), the severity of acute pancreatitis in the cerulein-treated rats was significantly ameliorated as evidenced by decreased α-amylase activities in the plasma and lessened oedema formation in the pancreatic parenchyma. In addition, the generation of intracellular reactive oxidative products, including malondialdehyde and protein carbonyls, was accordingly reduced, so as the production of pro-inflammatory cytokines. While inhibiting the activities of NADPH oxidase and myeloperoxidase, the depletion of glutathione was considerably restored. Importantly, the attenuation of pancreatic oxidative damage by dihydro-resveratrol was associated with a down-regulation of the nuclear factor-kappaB and phosphatidylinositol 3'-kinase-serine/threonine kinase signalling pathways. Furthermore, we demonstrated that the solubility of dihydro-resveratrol was at least 5 times higher than trans-resveratrol whilst exhibiting a much lower cytotoxicity. Collectively, the current findings accentuate new mechanistic insight of dihydro-resveratrol in pancreatic oxidative damage, and advocate its therapeutic potential for the management of acute pancreatitis, particularly for patients unresponsive to trans-resveratrol due to the lack of proper microbial strains. PMID:26971398

  6. Damage patterns of retinal nerve fiber layer in acute and chronic intraocular pressure elevation in primary angle closure glaucoma

    PubMed Central

    Liu, Xing; Li, Mei; Zhong, Yi-Min; Xiao, Hui; Huang, Jing-Jing; Kong, Xiang-Yun

    2010-01-01

    AIM To observe the differences of damage patterns of retinal nerve fiber layer (RNFL) between acute and chronic intraocular pressure (IOP) elevation in primary angle closure glaucoma (PACG) using optical coherence tomography (OCT). METHODS Twenty-four patients (48 eyes) with unilateral acute PACG (APACG) attack in the 6 months after admission and 36 patients (64 eyes) with chronic PACG (CPACG) were included in this prospective study. For all cases, IOP has been controlled under 21mmHg after treatment. Using stratus OCT, the RNFL thickness was assessed in eyes with PACG within 3 days, 2 weeks, 1, 3 and 6 months after IOP was controlled. Repeated measures ANOVA was used to examine the changes of RNFL thickness at different time after IOP being controlled in both acute attack eyes and unaffected fellow eyes of APACG and eyes with CPACG. RESULTS The mean RNFL thickness for the APACG-attacked eyes increased significantly within 3 days (121.49±23.84)µm after acute onset and then became thinner along with time [(107.22±24.72)µm at 2 weeks,(93.58±18.37)µm at 1 month, (84.10±19.89)µm at 3 months and (78.98±19.17)µm at 6 months]. In APACG-attacked eyes, there were significant differences of average RNFL thickness at 5 different times after IOP was controlled (P<0.001). In the APACG unaffected fellow eyes and CPACG eyes, there were no significant differences in mean RNFL thickness at 5 different times(F=0.450, P=0.104 in APACG unaffected fellow eyes and F=1.558, P=0.200 in CPACG eyes). There was significant difference for interaction between time periods and groups (F=1.912, P=0.003). CONCLUSION RNFL damage patterns are different under different IOP elevated courses. In APACG, RNFL was found to be swollen and thickening right after acute attack and then becomes thinning and atrophy along with the time, while RNFL was found to be diffused thinness in CPACG. PMID:22553541

  7. Biochanin A protects dopaminergic neurons against lipopolysaccharide-induced damage and oxidative stress in a rat model of Parkinson's disease.

    PubMed

    Wang, Jun; He, Can; Wu, Wang-Yang; Chen, Feng; Wu, Yang-Yang; Li, Wei-Zu; Chen, Han-Qing; Yin, Yan-Yan

    2015-11-01

    Parkinson's disease (PD) is the second most common neurodegenerative disease, which is characterized by loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc). Accumulated evidences have suggested that oxidative stress is closely associated with the dopaminergic neurodegeneration of PD that can be protected by antioxidants. Biochanin A that is an O-methylated isoflavone in chickpea is investigated to explore its protective mechanism on dopaminergic neurons of the unilateral lipopolysaccharide (LPS)-injected rat. The results showed that biochanin A significantly improved the animal model's behavioral symptoms, prevented the loss of dopaminergic neurons and inhibited the deleterious microglia activation in the LPS-induced rats. Moreover, biochanin A inhibited nicotinamide adenine dinucleotide phosphate oxidase (NADPH oxidase) activation and malondialdehyde (MDA) production, increased superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities in the rat brain. These results suggested that biochanin A might be a natural candidate with protective properties on dopaminergic neurons against the PD. PMID:26394281

  8. A Novel Therapy to Attenuate Acute Kidney Injury and Ischemic Allograft Damage after Allogenic Kidney Transplantation in Mice

    PubMed Central

    Gueler, Faikah; Shushakova, Nelli; Mengel, Michael; Hueper, Katja; Chen, Rongjun; Liu, Xiaokun; Park, Joon-Keun; Haller, Hermann

    2015-01-01

    Ischemia followed by reperfusion contributes to the initial damage to allografts after kidney transplantation (ktx). In this study we tested the hypothesis that a tetrapeptide EA-230 (AQGV), might improve survival and attenuate loss of kidney function in a mouse model of renal ischemia/reperfusion injury (IRI) and ischemia-induced delayed graft function after allogenic kidney transplantation. IRI was induced in male C57Bl/6N mice by transient bilateral renal pedicle clamping for 35 min. Treatment with EA-230 (20–50mg/kg twice daily i.p. for four consecutive days) was initiated 24 hours after IRI when acute kidney injury (AKI) was already established. The treatment resulted in markedly improved survival in a dose dependent manner. Acute tubular injury two days after IRI was diminished and tubular epithelial cell proliferation was significantly enhanced by EA-230 treatment. Furthermore, CTGF up-regulation, a marker of post-ischemic fibrosis, at four weeks after IRI was significantly less in EA-230 treated renal tissue. To learn more about these effects, we measured renal blood flow (RBF) and glomerular filtration rate (GFR) at 28 hours after IRI. EA-230 improved both GFR and RBF significantly. Next, EA-230 treatment was tested in a model of ischemia-induced delayed graft function after allogenic kidney transplantation. The recipients were treated with EA-230 (50 mg/kg) twice daily i.p. which improved renal function and allograft survival by attenuating ischemic allograft damage. In conclusion, EA-230 is a novel and promising therapeutic agent for treating acute kidney injury and preventing IRI-induced post-transplant ischemic allograft injury. Its beneficial effect is associated with improved renal perfusion after IRI and enhanced regeneration of tubular epithelial cells. PMID:25617900

  9. Effect of modified Bo-yang-Hwan-o-Tang, a polyherbal medicine on the hippocampal neuronal damage in a rat model of global ischemia

    PubMed Central

    Oh, Tae Woo; Jung, Hyo Won; Park, Yong-Ki

    2015-01-01

    Background: Chronic cerebral hypoperfusion has been well-characterized as a common pathological status contributing to vascular dementia (VD). In this study, the neuroprotective effect of modified Bo-yang-Hwan-O Tang (mBHT), a polyherbal medicine for ischemic stroke, was investigated in a rat model for global ischemia. Materials and Methods: Global ischemia model was prepared in Sprague-Dawley rats by the permanent occlusion of bilateral common carotid arteries (two-vessel occlusion [2VO])-induced chronic cerebral hypoperfusion. mBHT at doses of 250 and 500 mg/kg was orally administrated for 4 weeks once a day, 24 h after 2VO. Histopathological change of the hippocampal region was observed by hematoxylin and eosin, Nissl, and Fluoro-Jade B staining and immunohistochemistry with anti-glial fibrillary acidic protein and anti-neuronal nuclei antibodies. The expression of Bax, Bcl-2, and caspase-3 was investigated in the hippocampus by Western blot. The nuclear factor-kappa B (NF-κB) expression was also analyzed in hippocampal CA1 region using immunofluorescence staining. Results: The administration of mBHT at doses of 250 and 500 mg/kg significantly inhibited chronic cerebral hypoperfusion-induced neuronal damage and astroglial activation in the hippocampal CA1 region in 2VO rats. mBHT increased the NF-κB expression in the CA1 neuronal cells but decreased in activated astrocytes. In addition, mBHT significantly decreased the hippocampal expression of Bax and caspase-3 and increased the Bcl-2 expression in 2VO rats. Conclusions: Our data indicate that mBHT has a neuroprotective property in VD induced by chronic cerebral hypoperfusion through inhibiting the hippocampal neuronal damage and astrogliosis. PMID:26246747

  10. The novel mitochondrial iron chelator 5-((methylamino)methyl)-8-hydroxyquinoline protects against mitochondrial-induced oxidative damage and neuronal death.

    PubMed

    Mena, Natalia P; García-Beltrán, Olimpo; Lourido, Fernanda; Urrutia, Pamela J; Mena, Raúl; Castro-Castillo, Vicente; Cassels, Bruce K; Núñez, Marco T

    2015-08-01

    Abundant evidence indicates that iron accumulation, oxidative damage and mitochondrial dysfunction are common features of Huntington's disease, Parkinson's disease, Friedreich's ataxia and a group of disorders known as Neurodegeneration with Brain Iron Accumulation. In this study, we evaluated the effectiveness of two novel 8-OH-quinoline-based iron chelators, Q1 and Q4, to decrease mitochondrial iron accumulation and oxidative damage in cellular and animal models of PD. We found that at sub-micromolar concentrations, Q1 selectively decreased the mitochondrial iron pool and was extremely effective in protecting against rotenone-induced oxidative damage and death. Q4, in turn, preferentially chelated the cytoplasmic iron pool and presented a decreased capacity to protect against rotenone-induced oxidative damage and death. Oral administration of Q1 to mice protected substantia nigra pars compacta neurons against oxidative damage and MPTP-induced death. Taken together, our results support the concept that oral administration of Q1 is a promising therapeutic strategy for the treatment of NBIA. PMID:26051278

  11. Acute hydrodynamic damage induced by SPLITT fractionation and centrifugation in red blood cells.

    PubMed

    Urbina, Adriana; Godoy-Silva, Ruben; Hoyos, Mauricio; Camacho, Marcela

    2016-05-01

    Though blood bank processing traditionally employs centrifugation, new separation techniques may be appealing for large scale processes. Split-flow fractionation (SPLITT) is a family of techniques that separates in absence of labelling and uses very low flow rates and force fields, and is therefore expected to minimize cell damage. However, the hydrodynamic stress and possible consequent damaging effects of SPLITT fractionation have not been yet examined. The aim of this study was to investigate the hydrodynamic damage of SPLITT fractionation to human red blood cells, and to compare these effects with those induced by centrifugation. Peripheral whole blood samples were collected from healthy volunteers. Samples were diluted in a buffered saline solution, and were exposed to SPLITT fractionation (flow rates 1-10ml/min) or centrifugation (100-1500g) for 10min. Cell viability, shape, diameter, mean corpuscular hemoglobin, and membrane potential were measured. Under the operating conditions employed, both SPLITT and centrifugation maintained cell viability above 98%, but resulted in significant sublethal damage, including echinocyte formation, decreased cell diameter, decreased mean corpuscular hemoglobin, and membrane hyperpolarization which was inhibited by EGTA. Wall shear stress and maximum energy dissipation rate showed significant correlation with lethal and sublethal damage. Our data do not support the assumption that SPLITT fractionation induces very low shear stress and is innocuous to cell function. Some changes in SPLITT channel design are suggested to minimize cell damage. Measurement of membrane potential and cell diameter could provide a new, reliable and convenient basis for evaluation of hydrodynamic effects on different cell models, allowing identification of optimal operating conditions on different scales. PMID:27023157

  12. Design, synthesis and biological evaluation of novel chiral oxazino-indoles as potential and selective neuroprotective agents against Aβ25-35-induced neuronal damage.

    PubMed

    Chen, Jing; Tao, Ling-Xue; Xiao, Wei; Ji, Sha-Sha; Wang, Jian-Rong; Li, Xu-Wen; Zhang, Hai-Yan; Guo, Yue-Wei

    2016-08-01

    A series of chiral oxazino-indoles have been synthesized via a key intermolecular oxa-Pictet-Spengler reaction. These compounds exhibited significant and selective neuroprotective effects against Aβ25-35-induced neuronal damage. This is the first report of evaluating the influence of chiral diversity of oxazino-indoles on their neuroprotective activities, with the structure-activity relationship been analyzed. The highly active compounds 3f, 3g, 4g, 4h, and 6b all performed over 90% cell protection, providing a new direction for the development of neuroprotective agents against Alzheimer's disease. PMID:27301369

  13. Dexrazoxane Diminishes Doxorubicin-Induced Acute Ovarian Damage and Preserves Ovarian Function and Fecundity in Mice

    PubMed Central

    Ringelstetter, Ashley; Khatib, Hasan; Abbott, David H.; Salih, Sana M.

    2015-01-01

    Advances in cancer treatment utilizing multiple chemotherapies have dramatically increased cancer survivorship. Female cancer survivors treated with doxorubicin (DXR) chemotherapy often suffer from an acute impairment of ovarian function, which can persist as long-term, permanent ovarian insufficiency. Dexrazoxane (Dexra) pretreatment reduces DXR-induced insult in the heart, and protects in vitro cultured murine and non-human primate ovaries, demonstrating a drug-based shield to prevent DXR insult. The present study tested the ability of Dexra pretreatment to mitigate acute DXR chemotherapy ovarian toxicity in mice through the first 24 hours post-treatment, and improve subsequent long-term fertility throughout the reproductive lifespan. Adolescent CD-1 mice were treated with Dexra 1 hour prior to DXR treatment in a 1:1 mg or 10:1 mg Dexra:DXR ratio. During the acute injury period (2–24 hours post-injection), Dexra pretreatment at a 1:1 mg ratio decreased the extent of double strand DNA breaks, diminished γH2FAX activation, and reduced subsequent follicular cellular demise caused by DXR. In fertility and fecundity studies, dams pretreated with either Dexra:DXR dose ratio exhibited litter sizes larger than DXR-treated dams, and mice treated with a 1:1 mg Dexra:DXR ratio delivered pups with birth weights greater than DXR-treated females. While DXR significantly increased the “infertility index” (quantifying the percentage of dams failing to achieve pregnancy) through 6 gestations following treatment, Dexra pretreatment significantly reduced the infertility index following DXR treatment, improving fecundity. Low dose Dexra not only protected the ovaries, but also bestowed a considerable survival advantage following exposure to DXR chemotherapy. Mouse survivorship increased from 25% post-DXR treatment to over 80% with Dexra pretreatment. These data demonstrate that Dexra provides acute ovarian protection from DXR toxicity, improving reproductive health in a mouse

  14. Evolution of blood-brain barrier damage associated with changes in brain metabolites following acute ischemia.

    PubMed

    Yan, Gen; Xuan, Yinghua; Dai, Zhuozhi; Zhang, Guishan; Xu, Haiyun; Mikulis, David; Wu, Renhua

    2015-11-11

    Stroke is a serious medical condition that requires emergency care. In the case of ischemic stroke, ischemia may lead to damage to the blood-brain barrier (BBB); the damage in turn may exacerbate the condition. Therefore, noninvasive detection of BBB damage represents a challenge for experimental and clinical researchers. In this study, we assessed the onset of BBB disruption by means of T1-weighted images with administration of the contrast enhancement agent gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) and related BBB breakdown to brain metabolite changes in proton magnetic resonance spectrum (H-MRS) in the infarcted site following middle cerebral artery occlusion (MCAO) in rats. It was shown that MCAO for 30 min and 1.5 h caused no Gd-DTPA signal change in the T1-weighted images, whereas MCAO for 1 h significantly altered some of H-MRS brain metabolites, suggesting that brain metabolite changes occurred earlier than BBB damage after ischemic stroke. MCAO for 2 h caused BBB breakdown, which was related to changes in the levels of some brain metabolites detected by H-MRS. Between the second and the third hour after MCAO, brain metabolite changes continued as the result of BBB breakdown and the concurrent overperfusion to the infarcted site, which may ameliorate the metabolite changes, thus compensating for the functional failures of the brain after stroke. PMID:26366833

  15. Oral Supplementation of Glucosamine Fails to Alleviate Acute Kidney Injury in Renal Ischemia-Reperfusion Damage

    PubMed Central

    Johnsen, Marc; Späth, Martin Richard; Denzel, Martin S.; Göbel, Heike; Kubacki, Torsten; Hoyer, Karla Johanna Ruth; Hinze, Yvonne; Benzing, Thomas; Schermer, Bernhard; Antebi, Adam; Burst, Volker; Müller, Roman-Ulrich

    2016-01-01

    Acute kidney injury is a leading contributor to morbidity and mortality in the ageing population. Proteotoxic stress response pathways have been suggested to contribute to the development of acute renal injury. Recent evidence suggests that increased synthesis of N-glycan precursors in the hexosamine pathway as well as feeding of animals with aminosugars produced in the hexosamine pathway may increase stress resistance through reducing proteotoxic stress and alleviate pathology in model organisms. As feeding of the hexosamine pathway metabolite glucosamine to aged mice increased their life expectancy we tested whether supplementation of this aminosugar may also protect mice from acute kidney injury after renal ischemia and reperfusion. Animals were fed for 4 weeks ad libitum with standard chow or standard chow supplemented with 0.5% N-acetylglucosamine. Preconditioning with caloric restriction for four weeks prior to surgery served as a positive control for protective dietary effects. Whereas caloric restriction demonstrated the known protective effect both on renal function as well as survival in the treated animals, glucosamine supplementation failed to promote any protection from ischemia-reperfusion injury. These data show that although hexosamine pathway metabolites have a proven role in enhancing protein quality control and survival in model organisms oral glucosamine supplementation at moderate doses that would be amenable to humans does not promote protection from ischemia-reperfusion injury of the kidney. PMID:27557097

  16. Selenium Pretreatment for Mitigation of Ischemia/Reperfusion Injury in Cardiovascular Surgery: Influence on Acute Organ Damage and Inflammatory Response.

    PubMed

    Steinbrenner, Holger; Bilgic, Esra; Pinto, Antonio; Engels, Melanie; Wollschläger, Lena; Döhrn, Laura; Kellermann, Kristine; Boeken, Udo; Akhyari, Payam; Lichtenberg, Artur

    2016-08-01

    Ischemia/reperfusion injury (IRI) contributes to morbidity and mortality after cardiovascular surgery requiring cardiopulmonary bypass (CPB) and deep hypothermic circulatory arrest (DHCA). Multi-organ damage is associated with substantial decreases of blood selenium (Se) levels in patients undergoing cardiac surgery with CPB. We compared the influence of a dietary surplus of Se and pretreatment with ebselen, a mimic of the selenoenzyme glutathione peroxidase, on IRI-induced tissue damage and inflammation. Male Wistar rats were fed either a Se-adequate diet containing 0.3 ppm Se or supplemented with 1 ppm Se (as sodium selenite) for 5 weeks. Two other groups of Se-adequate rats received intraperitoneal injection of ebselen (30 mg/kg) or DMSO (solvent control) before surgery. The animals were connected to a heart-lung-machine and underwent 45 min of global ischemia during circulatory arrest at 16 °C, followed by re-warming and reperfusion. Selenite and ebselen suppressed IRI-induced leukocytosis and the increase in plasma levels of tissue damage markers (AST, ALT, LDH, troponin) during surgery but did not prevent the induction of proinflammatory cytokines (IL-6, TNF-α). Both Se compounds affected phosphorylation and expression of proteins related to stress response and inflammation: Ebselen increased phosphorylation of STAT3 transcription factor in the heart and decreased phosphorylation of ERK1/2 MAP kinases in the lungs. Selenite decreased ERK1/2 phosphorylation and HSP-70 expression in the heart. Pretreatment with selenite or ebselen protected against acute IRI-induced tissue damage during CPB and DHCA. Potential implications of their different actions with regard to molecular stress markers on the recovery after surgery represent promising targets for further investigation. PMID:27192987

  17. The stressed female brain: neuronal activity in the prelimbic but not infralimbic region of the medial prefrontal cortex suppresses learning after acute stress.

    PubMed

    Maeng, Lisa Y; Shors, Tracey J

    2013-01-01

    Women are nearly twice as likely as men to suffer from anxiety and post-traumatic stress disorder (PTSD), indicating that many females are especially vulnerable to stressful life experience. A profound sex difference in the response to stress is also observed in laboratory animals. Acute exposure to an uncontrollable stressful event disrupts associative learning during classical eyeblink conditioning in female rats but enhances this same type of learning process in males. These sex differences in response to stress are dependent on neuronal activity in similar but also different brain regions. Neuronal activity in the basolateral nucleus of the amygdala (BLA) is necessary in both males and females. However, neuronal activity in the medial prefrontal cortex (mPFC) during the stressor is necessary to modify learning in females but not in males. The mPFC is often divided into its prelimbic (PL) and infralimbic (IL) subregions, which differ both in structure and function. Through its connections to the BLA, we hypothesized that neuronal activity within the PL, but not IL, during the stressor is necessary to suppress learning in females. To test this hypothesis, either the PL or IL of adult female rats was bilaterally inactivated with GABAA agonist muscimol during acute inescapable swim stress. About 24 h later, all subjects were trained with classical eyeblink conditioning. Though stressed, females without neuronal activity in the PL learned well. In contrast, females with IL inactivation during the stressor did not learn well, behaving similarly to stressed vehicle-treated females. These data suggest that exposure to a stressful event critically engages the PL, but not IL, to disrupt associative learning in females. Together with previous studies, these data indicate that the PL communicates with the BLA to suppress learning after a stressful experience in females. This circuit may be similarly engaged in women who become cognitively impaired after stressful life

  18. Rat liver mitochondrial damage under acute or chronic carbon tetrachloride-induced intoxication: Protection by melatonin and cranberry flavonoids

    SciTech Connect

    Cheshchevik, V.T.; Lapshina, E.A.; Dremza, I.K.; Zabrodskaya, S.V.; Reiter, R.J.; Prokopchik, N.I.; Zavodnik, I.B.

    2012-06-15

    In current societies, the risk of toxic liver damage has markedly increased. The aim of the present work was to carry out further research into the mechanism(s) of liver mitochondrial damage induced by acute (0.8 g/kg body weight, single injection) or chronic (1.6 g/ kg body weight, 30 days, biweekly injections) carbon tetrachloride – induced intoxication and to evaluate the hepatoprotective potential of the antioxidant, melatonin, as well as succinate and cranberry flavonoids in rats. Acute intoxication resulted in considerable impairment of mitochondrial respiratory parameters in the liver. The activity of mitochondrial succinate dehydrogenase (complex II) decreased (by 25%, p < 0.05). Short-term melatonin treatment (10 mg/kg, three times) of rats did not reduce the degree of toxic mitochondrial dysfunction but decreased the enhanced NO production. After 30-day chronic intoxication, no significant change in the respiratory activity of liver mitochondria was observed, despite marked changes in the redox-balance of mitochondria. The activities of the mitochondrial enzymes, succinate dehydrogenase and glutathione peroxidase, as well as that of cytoplasmic catalase in liver cells were inhibited significantly. Mitochondria isolated from the livers of the rats chronically treated with CCl{sub 4} displayed obvious irreversible impairments. Long-term melatonin administration (10 mg/kg, 30 days, daily) to chronically intoxicated rats diminished the toxic effects of CCl{sub 4}, reducing elevated plasma activities of alanine aminotransferase and aspartate aminotransferase and bilirubin concentration, prevented accumulation of membrane lipid peroxidation products in rat liver and resulted in apparent preservation of the mitochondrial ultrastructure. The treatment of the animals by the complex of melatonin (10 mg/kg) plus succinate (50 mg/kg) plus cranberry flavonoids (7 mg/kg) was even more effective in prevention of toxic liver injury and liver mitochondria damage

  19. Acute ZnO nanoparticles exposure induces developmental toxicity, oxidative stress and DNA damage in embryo-larval zebrafish.

    PubMed

    Zhao, Xuesong; Wang, Shutao; Wu, Yuan; You, Hong; Lv, Lina

    2013-07-15

    Nano-scale zinc oxide (nano-ZnO) is widely used in various industrial and commercial applications. However, the available toxicological information was inadequate to assess the potential ecological risk of nano-ZnO to aquatic organisms and the publics. In this study, the developmental toxicity, oxidative stress and DNA damage of nano-ZnO embryos were investigated in the embryo-larval zebrafish, the toxicity of Zn(2+) releasing from nano-ZnO were also investigated to ascertain the relationship between the nano-ZnO and corresponding Zn(2+). Zebrafish embryos were exposed to 1, 5, 10, 20, 50, and 100mg/L nano-ZnO and 0.59, 2.15, 3.63, 4.07, 5.31, and 6.04 mg/L Zn(2+) for 144 h post-fertilisation (hpf), respectively. Up to 144 hpf, activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), and malondialdehyde (MDA) contents, the genes related to oxidative damage, reactive oxygen species (ROS) generation and DNA damage in zebrafish embryos were measured. The nano-ZnO was found to exert a dose-dependent toxicity to zebrafish embryos and larvae, reducing the hatching rate and inducing malformation and the acute toxicity to zebrafish embryos was greater than that of the Zn(2+) solution. The generation of ROS was significantly increased at 50 and 100mg/L nano-ZnO. DNA damage of zebrafish embryo was evaluated by single-cell gel electrophoresis and was enhanced with increasing nano-ZnO concentration. Moreover, the transcriptional expression of mitochondrial inner membrane genes related to ROS production, such as Bcl-2, in response to oxidative damage, such as Nqo1, and related to antioxidant response element such as Gstp2 were significantly down-regulated in the nano-ZnO treatment groups. However, the nano-ZnO up-regulated the transcriptional expression of Ucp2-related to ROS production. In conclusion, nano-ZnO induces developmental toxicity, oxidative stress and DNA damage on zebrafish embryos and the dissolved Zn(2+) only partially

  20. Lycopene protects against acute zearalenone-induced oxidative, endocrine, inflammatory and reproductive damages in male mice.

    PubMed

    Boeira, Silvana Peterini; Funck, Vinícius Rafael; Borges Filho, Carlos; Del'Fabbro, Lucian; de Gomes, Marcelo Gomes; Donato, Franciele; Royes, Luiz Fernando Freire; Oliveira, Mauro Schneider; Jesse, Cristiano Ricardo; Furian, Ana Flávia

    2015-03-25

    Male mice received lycopene for 10 days before a single oral administration of zearalenone (ZEA). After 48 h testes and blood were collected. Mice treated with lycopene/ZEA exhibited amelioration of the hematological changes. Lycopene prevented the reduction in the number and motility of spermatozoa and testosterone levels, indicating a protective effect in the testicular damage induced by ZEA. Lycopene was also effective in protecting against the decrease in glutathione-S-transferase, glutathione peroxidase, glutathione reductase and δ-aminolevulinic acid dehydratase activities caused by ZEA in the testes. Exposure of animals to ZEA induced modification of antioxidant and inflammatory status with increase of reduced glutathione (GSH) levels and increase of the oxidized glutathione, interleukins 1β, 2, 6, 10, tumor necrosis factor-α and bilirubin levels. Lycopene prevented ZEA-induced changes in GSH levels and inhibited the processes of inflammation, reducing the damage induced by ZEA. Altogether, our results indicate that lycopene was able to prevent ZEA-induced damage in the mice. PMID:25682699

  1. DNA damage in organs of mice treated acutely with patulin, a known mycotoxin.

    PubMed

    de Melo, Flávia Terezinha; de Oliveira, Iuri Marques; Greggio, Samuel; Dacosta, Jaderson Costa; Guecheva, Temenouga Nikolova; Saffi, Jenifer; Henriques, João Antonio Pêgas; Rosa, Renato Moreira

    2012-10-01

    Patulin, a known mycotoxin, is considered a significant contaminant in apples, apple-derived products and feeds. This study investigated the genotoxic effects of patulin in multiple organs (brain, kidney, liver and urinary bladder) of mice using an in vivo comet assay. We assessed the mechanism underlying this genotoxicity by measuring the GSH content and the thiobarbituric acid-reactive species (TBARS) level. Male CF-1 mice were given 1.0-3.75 mg/kg patulin intraperitoneally. The effect of patulin was dose-dependent and the highest patulin dose induced DNA strand breaks in the brain (damage index, DI, in hippocampus increased from 36.2 in control animals to 127.5), liver (44.3-138.4) and kidneys (31.5-99); decreased levels of GSH (hippocampus--from 46.9 to 18.4 nmol/mg protein); and an increase in lipid peroxidation (hippocampus--from 5.8 to 20.3 MDA equivalents/mg protein). This finding establishes an interrelationship between the pro-oxidant and genotoxic effects of patulin. Pre-treatment administration of N-acetyl-cysteine reduced patulin-induced DNA damage (hippocampus--DI from 127.5 to 39.8) and lipid peroxidation (hippocampus--20.3 to 12.8 MDA equivalents/mg protein) by restoring cellular GSH levels, reinforcing the positive relationship between patulin-induced GSH depletion and DNA damage caused by systemic administration of this mycotoxin. PMID:22222931

  2. Protein tyrosine kinase regulates α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor trafficking induced by acute hypoxia in cultured brainstem neurons.

    PubMed

    Wang, H; Yu, L C; Li, Y C

    2016-01-01

    This study was performed to investigate the modulation effect of protein tyrosine kinase on postsynaptic a-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor trafficking induced by acute hypoxia in cultured brainstem neurons. The cultured neurons were exposed to 1% O2 and the expression of AMPA receptor subunit GluR2 on the cell surface was significantly increased, while total GluR2 was not markedly changed. Furthermore, the hypoxia-induced increase in GluR2 expression on the cell surface was partially blocked by the protein tyrosine kinase membrane-permeable inhibitor genistein. In contrast, both the protein tyrosine kinase agonist nerve growth factor and protein tyrosine phosphatase inhibitor vanadate promoted the hypoxia-induced increase of GluR2 expression on cell surface. Moreover, GluR2 could be phosphorylated by tyrosine under normoxia and hypoxia conditions in vitro on brainstem neurons, and tyrosine phosphorylation of GluR2 was significantly stronger under hypoxia conditions. Our results indicate that acute hypoxia induces the AMPA receptor subunit GluR2 to rapidly migrate to the cell membrane to modify the strength of the synapse. This study indicates that tyrosine phosphorylation of the receptor is an important pathway regulating the rapid migration of GluR2 in the postsynaptic domain induced by hypoxia. PMID:27525851

  3. Volatile Organic Compound Gamma-Butyrolactone Released upon Herpes Simplex Virus Type -1 Acute Infection Modulated Membrane Potential and Repressed Viral Infection in Human Neuron-Like Cells

    PubMed Central

    Waguespack, Yan; Figliozzi, Robert W.; Kharel, Madan K.; Zhang, Qiaojuan; Martin-Caraballo, Miguel

    2016-01-01

    Herpes Simplex Virus Type -1 (HSV-1) infections can cause serious complications such as keratitis and encephalitis. The goal of this study was to identify any changes in the concentrations of volatile organic compounds (VOCs) produced during HSV-1 infection of epithelial cells that could potentially be used as an indicator of a response to stress. An additional objective was to study if any VOCs released from acute epithelial infection may influence subsequent neuronal infection to facilitate latency. To investigate these hypotheses, Vero cells were infected with HSV-1 and the emission of VOCs was analyzed using two-dimensional gas chromatograph/mass spectrometry (2D GC/MS). It was observed that the concentrations of gamma-butyrolactone (GBL) in particular changed significantly after a 24-hour infection. Since HSV-1 may establish latency in neurons after the acute infection, GBL was tested to determine if it exerts neuronal regulation of infection. The results indicated that GBL altered the resting membrane potential of differentiated LNCaP cells and promoted a non-permissive state of HSV-1 infection by repressing viral replication. These observations may provide useful clues towards understanding the complex signaling pathways that occur during the HSV-1 primary infection and establishment of viral latency. PMID:27537375

  4. Volatile Organic Compound Gamma-Butyrolactone Released upon Herpes Simplex Virus Type -1 Acute Infection Modulated Membrane Potential and Repressed Viral Infection in Human Neuron-Like Cells.

    PubMed

    Rochford, Kevin; Chen, Feng; Waguespack, Yan; Figliozzi, Robert W; Kharel, Madan K; Zhang, Qiaojuan; Martin-Caraballo, Miguel; Hsia, S Victor

    2016-01-01

    Herpes Simplex Virus Type -1 (HSV-1) infections can cause serious complications such as keratitis and encephalitis. The goal of this study was to identify any changes in the concentrations of volatile organic compounds (VOCs) produced during HSV-1 infection of epithelial cells that could potentially be used as an indicator of a response to stress. An additional objective was to study if any VOCs released from acute epithelial infection may influence subsequent neuronal infection to facilitate latency. To investigate these hypotheses, Vero cells were infected with HSV-1 and the emission of VOCs was analyzed using two-dimensional gas chromatograph/mass spectrometry (2D GC/MS). It was observed that the concentrations of gamma-butyrolactone (GBL) in particular changed significantly after a 24-hour infection. Since HSV-1 may establish latency in neurons after the acute infection, GBL was tested to determine if it exerts neuronal regulation of infection. The results indicated that GBL altered the resting membrane potential of differentiated LNCaP cells and promoted a non-permissive state of HSV-1 infection by repressing viral replication. These observations may provide useful clues towards understanding the complex signaling pathways that occur during the HSV-1 primary infection and establishment of viral latency. PMID:27537375

  5. Ameliorating effects of traditional Chinese medicine preparation, Chinese materia medica and active compounds on ischemia/reperfusion-induced cerebral microcirculatory disturbances and neuron damage.

    PubMed

    Sun, Kai; Fan, Jingyu; Han, Jingyan

    2015-01-01

    Ischemic stroke and ischemia/reperfusion (I/R) injury induced by thrombolytic therapy are conditions with high mortality and serious long-term physical and cognitive disabilities. They have a major impact on global public health. These disorders are associated with multiple insults to the cerebral microcirculation, including reactive oxygen species (ROS) overproduction, leukocyte adhesion and infiltration, brain blood barrier (BBB) disruption, and capillary hypoperfusion, ultimately resulting in tissue edema, hemorrhage, brain injury and delayed neuron damage. Traditional Chinese medicine (TCM) has been used in China, Korea, Japan and other Asian countries for treatment of a wide range of diseases. In China, the usage of compound TCM preparation to treat cerebrovascular diseases dates back to the Han Dynasty. Even thousands of years earlier, the medical formulary recorded many classical prescriptions for treating cerebral I/R-related diseases. This review summarizes current information and underlying mechanisms regarding the ameliorating effects of compound TCM preparation, Chinese materia medica, and active components on I/R-induced cerebral microcirculatory disturbances, brain injury and neuron damage. PMID:26579420

  6. Repeated febrile convulsions impair hippocampal neurons and cause synaptic damage in immature rats: neuroprotective effect of fructose-1,6-diphosphate

    PubMed Central

    Zhou, Jianping; Wang, Fan; Zhang, Jun; Gao, Hui; Yang, Yufeng; Fu, Rongguo

    2014-01-01

    Fructose-1,6-diphosphate is a metabolic intermediate that promotes cell metabolism. We hypothesize that fructose-1,6-diphosphate can protect against neuronal damage induced by febrile convulsions. Hot-water bathing was used to establish a repetitive febrile convulsion model in rats aged 21 days, equivalent to 3–5 years in humans. Ninety minutes before each seizure induction, rats received an intraperitoneal injection of low- or high-dose fructose-1,6-diphosphate (500 or 1,000 mg/kg, respectively). Low- and high-dose fructose-1,6-diphosphate prolonged the latency and shortened the duration of seizures. Furthermore, high-dose fructose-1,6-diphosphate effectively reduced seizure severity. Transmission electron microscopy revealed that 24 hours after the last seizure, high-dose fructose-1,6-diphosphate reduced mitochondrial swelling, rough endoplasmic reticulum degranulation, Golgi dilation and synaptic cleft size, and increased synaptic active zone length, postsynaptic density thickness, and synaptic interface curvature in the hippocampal CA1 area. The present findings suggest that fructose-1,6-diphosphate is a neuroprotectant against hippocampal neuron and synapse damage induced by repeated febrile convulsion in immature rats. PMID:25206915

  7. Ameliorating effects of traditional Chinese medicine preparation, Chinese materia medica and active compounds on ischemia/reperfusion-induced cerebral microcirculatory disturbances and neuron damage

    PubMed Central

    Sun, Kai; Fan, Jingyu; Han, Jingyan

    2015-01-01

    Ischemic stroke and ischemia/reperfusion (I/R) injury induced by thrombolytic therapy are conditions with high mortality and serious long-term physical and cognitive disabilities. They have a major impact on global public health. These disorders are associated with multiple insults to the cerebral microcirculation, including reactive oxygen species (ROS) overproduction, leukocyte adhesion and infiltration, brain blood barrier (BBB) disruption, and capillary hypoperfusion, ultimately resulting in tissue edema, hemorrhage, brain injury and delayed neuron damage. Traditional Chinese medicine (TCM) has been used in China, Korea, Japan and other Asian countries for treatment of a wide range of diseases. In China, the usage of compound TCM preparation to treat cerebrovascular diseases dates back to the Han Dynasty. Even thousands of years earlier, the medical formulary recorded many classical prescriptions for treating cerebral I/R-related diseases. This review summarizes current information and underlying mechanisms regarding the ameliorating effects of compound TCM preparation, Chinese materia medica, and active components on I/R-induced cerebral microcirculatory disturbances, brain injury and neuron damage. PMID:26579420

  8. Hepatoprotective effect of the natural fruit juice from Aronia melanocarpa on carbon tetrachloride-induced acute liver damage in rats.

    PubMed

    Valcheva-Kuzmanova, S; Borisova, P; Galunska, B; Krasnaliev, I; Belcheva, A

    2004-12-01

    The fruits of Aronia melanocarpa are rich in anthocyanins--plant pigments with anti-inflammatory and antioxidant activity. We studied the effect of the natural fruit juice from A. melanocarpa (NFJAM) on carbon tetrachloride (CCl4)-induced acute liver damage in rats. Histopathological changes such as necrosis, fatty change, ballooning degeneration and inflammatory infiltration of lymphocytes around the central veins occurred in rats following acute exposure to CCl4 (0.2 ml kg(-1), 2 days). The administration of CCl4 increased plasma aspartate transaminase (AST) and alanine transaminase (ALT) activities, induced lipid peroxidation (as measured by malondialdehyde (MDA) content in rat liver and plasma) and caused a depletion of liver reduced glutathione (GSH). NFJAM (5, 10 and 20 ml kg(-1), 4 days) dose-dependently reduced the necrotic changes in rat liver and inhibited the increase of plasma AST and ALT activities, induced by CCl4 (0.2ml kg(-1), 3rd and 4th days). NFJAM also prevented the CCl4-induced elevation of MDA formation and depletion of GSH content in rat liver. PMID:15625789

  9. Contribution of damage-associated molecular patterns to transfusion-related acute lung injury in cardiac surgery

    PubMed Central

    Müller, Marcella C.A.; Tuinman, Pieter R.; Vlaar, Alexander P.; Tuip, Anita M.; Maijoor, Kelly; Achouiti, Achmed; van t Veer, Cornelis; Vroom, Margreeth B.; Juffermans, Nicole P.

    2014-01-01

    Background The incidence of transfusion-related acute lung injury (TRALI) in cardiac surgery patients is high and this condition contributes to an adverse outcome. Damage-associated molecular pattern (DAMP) molecules, HMGB1 and S100A12, are thought to mediate inflammatory changes in acute respiratory distress syndrome. We aimed to determine whether DAMP are involved in the pathogenesis of TRALI in cardiac surgery patients. Materials and methods This was a secondary analysis of a prospective observational trial in cardiac surgery patients admitted to the Intensive Care Unit of a university hospital in the Netherlands. Fourteen TRALI cases were randomly matched with 32 transfused and non-transfused controls. Pulmonary levels of HMGB1, S100A12 and inflammatory cytokines (interleukins-1β, -6, and -8 and tumour necrosis factor-α) were determined when TRALI evolved. In addition, systemic and pulmonary levels of soluble receptor for advanced glycation end products (sRAGE) were determined. Results HMGB1 expression and levels of sRAGE in TRALI patients did not differ from those in controls. There was a trend towards higher S100A12 levels in TRALI patients compared to the controls. Furthermore, S100A12 levels were associated with increased levels of markers of pulmonary inflammation, prolonged cardiopulmonary bypass, hypoxemia and duration of mechanical ventilation. Conclusion No evidence was found that HMGB1 and sRAGE contribute to the development of TRALI. S100A12 is associated with duration of cardiopulmonary bypass, pulmonary inflammation, hypoxia and prolonged mechanical ventilation and may contribute to acute lung injury in cardiac surgery patients. PMID:24887223

  10. Long-Term Treatment with Losartan Attenuates Seizure Activity and Neuronal Damage Without Affecting Behavioral Changes in a Model of Co-morbid Hypertension and Epilepsy.

    PubMed

    Tchekalarova, Jana D; Ivanova, Natasha; Atanasova, Dimitrina; Pechlivanova, Daniela M; Lazarov, Nikolai; Kortenska, Lidia; Mitreva, Rumiana; Lozanov, Valentin; Stoynev, Alexander

    2016-08-01

    Over the last 10 years, accumulated experimental and clinical evidence has supported the idea that AT1 receptor subtype is involved in epilepsy. Recently, we have shown that the selective AT1 receptor antagonist losartan attenuates epileptogenesis and exerts neuroprotection in the CA1 area of the hippocampus in epileptic Wistar rats. This study aimed to verify the efficacy of long-term treatment with losartan (10 mg/kg) after kainate-induced status epilepticus (SE) on seizure activity, behavioral and biochemical changes, and neuronal damage in a model of co-morbid hypertension and epilepsy. Spontaneous seizures were video- and EEG-monitored in spontaneously hypertensive rats (SHRs) for a 16-week period after SE. The behavior was analyzed by open field, elevated plus maze, sugar preference test, and forced swim test. The levels of serotonin in the hippocampus and neuronal loss were estimated by HPLC and hematoxylin and eosin staining, respectively. The AT1 receptor antagonism delayed the onset of seizures and alleviated their frequency and duration during and after discontinuation of treatment. Losartan showed neuroprotection mostly in the CA3 area of the hippocampus and the septo-temporal hilus of the dentate gyrus in SHRs. However, the AT1 receptor antagonist did not exert a substantial influence on concomitant with epilepsy behavioral changes and decreased 5-HT levels in the hippocampus. Our results suggest that the antihypertensive therapy with an AT1 receptor blocker might be effective against seizure activity and neuronal damage in a co-morbid hypertension and epilepsy. PMID:26464042

  11. Rho kinase inhibition following traumatic brain injury in mice promotes functional improvement and acute neuron survival but has little effect on neurogenesis, glial responses or neuroinflammation.

    PubMed

    Bye, Nicole; Christie, Kimberly J; Turbic, Alisa; Basrai, Harleen S; Turnley, Ann M

    2016-05-01

    Inhibition of the Rho/Rho kinase pathway has been shown to be beneficial in a variety of neural injuries and diseases. In this manuscript we investigate the role of Rho kinase inhibition in recovery from traumatic brain injury using a controlled cortical impact model in mice. Mice subjected to a moderately severe TBI were treated for 1 or 4weeks with the Rho kinase inhibitor Y27632, and functional outcomes and neuronal and glial cell responses were analysed at 1, 7 and 35days post-injury. We hypothesised that Y27632-treated mice would show functional improvement, with augmented recruitment of neuroblasts from the SVZ and enhanced survival of newborn neurons in the pericontusional cortex, with protection against neuronal degeneration, neuroinflammation and modulation of astrocyte reactivity and blood-brain-barrier permeability. While Rho kinase inhibition enhanced recovery of motor function after trauma, there were no substantial increases in the recruitment of DCX(+) neuroblasts or the number of BrdU(+) or EdU(+) labelled newborn neurons in the pericontusional cortex of Y27632-treated mice. Inhibition of Rho kinase significantly reduced the number of degenerating cortical neurons at 1day post-injury compared to saline controls but had no longer term effect on neuronal degeneration, with only modest effects on astrocytic reactivity and macrophage/microglial responses. Overall, this study showed that Rho kinase contributes to acute neurodegenerative processes in the injured cortex but does not play a significant role in SVZ neural precursor cell-derived adult neurogenesis, glial responses or blood-brain barrier permeability following a moderately severe brain injury. PMID:26896832

  12. Acute Effects of Transforming Growth Factor-β1 on Neuronal Excitability and Involvement in the Pain of Rats with Chronic Pancreatitis

    PubMed Central

    Zhang, Xiaoyu; Zheng, Hang; Zhu, Hong-Yan; Hu, Shufen; Wang, Shusheng; Jiang, Xinghong; Xu, Guang-Yin

    2016-01-01

    Background/Aims This study was to investigate whether transforming growth factor-β1 (TGF-β1) plays a role in hyperalgesia in chronic pancreatitis (CP) and the underlying mechanisms. Methods CP was induced in male adult rats by intraductal injection of trinitrobenzene sulfonic acid (TNBS). Abdominal hyperalgesia was assessed by referred somatic behaviors to mechanical stimulation of rat abdomen. Dil dye injected into the pancreas was used to label pancreas-specific dorsal root ganglion (DRG) neurons. Whole cell patch clamp recordings and calcium imaging were performed to examine the effect of TGF-β1 on acutely isolated pancreas-specific DRG neurons. Western blot analysis was carried out to measure the expression of TGF-β1 and its receptors. Results TNBS injection significantly upregulated expression of TGF-β1 in the pancreas and DRGs, and TGF-β1 receptors in DRGs (T9-T13) in CP rats. Intrathecal injection of TGF-β receptor I antagonist SB431542 attenuated abdominal hyperalgesia in CP rats. TGF-β1 application depolarized the membrane potential and caused firing activity of DRG neurons. TGF-β1 application also reduced rheobase, hyperpolarized action potential threshold, and increased numbers of action potentials evoked by current injection of pancreas-specific DRG neurons. TGF-β1 application also increased the concentration of intracellular calcium of DRG neurons, which was inhibited by SB431542. Furthermore, intrathecal injection of TGF-β1 produced abdominal hyperalgesia in healthy rats. Conclusions These results suggest that TGF-β1 enhances neuronal excitability and increases the concentration of intracellular calcium. TGF-β1 and its receptors are involved in abdominal hyperalgesia in CP. This and future study might identify a potentially novel target for the treatment of abdominal pain in CP. PMID:26645248

  13. Acute Oxidative Effect and Muscle Damage after a Maximum 4 Min Test in High Performance Athletes

    PubMed Central

    Fernandes Filho, José; Fernandes, Luiz Cláudio

    2016-01-01

    The purpose of this investigation was to determine lipid peroxidation markers, physiological stress and muscle damage in elite kayakers in response to a maximum 4-min kayak ergometer test (KE test), and possible correlations with individual 1000m kayaking performances. The sample consisted of twenty-three adult male and nine adult female elite kayakers, with more than three years’ experience in international events, who voluntarily took part in this study. The subjects performed a 10-min warm-up, followed by a 2-min passive interval, before starting the test itself, which consisted of a maximum 4-min work paddling on an ergometer; right after the end of the test, an 8 ml blood sample was collected for analysis. 72 hours after the test, all athletes took part in an official race, when then it was possible to check their performance in the on site K1 1000m test (P1000m). The results showed that all lipoproteins and hematological parameters tested presented a significant difference (p≤0.05) after exercise for both genders. In addition, parameters related to muscle damage such as lactate dehydrogenase (LDH) and creatine kinase (CK) presented significant differences after stress. Uric acid presented an inverse correlation with the performance (r = -0.76), while CK presented a positive correlation (r = 0.46) with it. Based on these results, it was possible to verify muscle damage and the level of oxidative stress caused by indoor training with specific ergometers for speed kayaking, highlighting the importance of analyzing and getting to know the physiological responses to this type of training, in order to provide information to coaches and optimize athletic performance. PMID:27111088

  14. Acute pancreatitis decreases the sensitivity of pancreas-projecting dorsal motor nucleus of the vagus neurones to group II metabotropic glutamate receptor agonists in rats

    PubMed Central

    Babic, Tanja; Travagli, R Alberto

    2014-01-01

    Recent studies have shown that pancreatic exocrine secretions (PES) are modulated by dorsal motor nucleus of the vagus (DMV) neurones, whose activity is finely tuned by GABAergic and glutamatergic synaptic inputs. Group II metabotropic glutamate receptors (mGluR) decrease synaptic transmission to pancreas-projecting DMV neurones and increase PES. In the present study, we used a combination of in vivo and in vitro approaches aimed at characterising the effects of caerulein-induced acute pancreatitis (AP) on the vagal neurocircuitry modulating pancreatic functions. In control rats, microinjection of bicuculline into the DMV increased PES, whereas microinjections of kynurenic acid had no effect. Conversely, in AP rats, microinjection of bicuculline had no effect, whereas kynurenic acid decreased PES. DMV microinjections of the group II mGluR agonist APDC and whole cell recordings of excitatory currents in identified pancreas-projecting DMV neurones showed a reduced functional response in AP rats compared to controls. Moreover, these changes persisted up to 3 weeks following the induction of AP. These data demonstrate that AP increases the excitatory input to pancreas-projecting DMV neurones by decreasing the response of excitatory synaptic terminals to group II mGluR agonist. PMID:24445314

  15. The Insect Peptide Coprisin Prevents Clostridium difficile-Mediated Acute Inflammation and Mucosal Damage through Selective Antimicrobial Activity▿

    PubMed Central

    Kang, Jin Ku; Hwang, Jae Sam; Nam, Hyo Jung; Ahn, Keun Jae; Seok, Heon; Kim, Sung-Kuk; Yun, Eun Young; Pothoulakis, Charalabos; Lamont, John Thomas; Kim, Ho

    2011-01-01

    Clostridium difficile-associated diarrhea and pseudomembranous colitis are typically treated with vancomycin or metronidazole, but recent increases in relapse incidence and the emergence of drug-resistant strains of C. difficile indicate the need for new antibiotics. We previously isolated coprisin, an antibacterial peptide from Copris tripartitus, a Korean dung beetle, and identified a nine-amino-acid peptide in the α-helical region of it (LLCIALRKK) that had antimicrobial activity (J.-S. Hwang et al., Int. J. Pept., 2009, doi:10.1155/2009/136284). Here, we examined whether treatment with a coprisin analogue (a disulfide dimer of the nine peptides) prevented inflammation and mucosal damage in a mouse model of acute gut inflammation established by administration of antibiotics followed by C. difficile infection. In this model, coprisin treatment significantly ameliorated body weight decreases, improved the survival rate, and decreased mucosal damage and proinflammatory cytokine production. In contrast, the coprisin analogue had no apparent antibiotic activity against commensal bacteria, including Lactobacillus and Bifidobacterium, which are known to inhibit the colonization of C. difficile. The exposure of C. difficile to the coprisin analogue caused a marked increase in nuclear propidium iodide (PI) staining, indicating membrane damage; the staining levels were similar to those seen with bacteria treated with a positive control for membrane disruption (EDTA). In contrast, coprisin analogue treatment did not trigger increases in the nuclear PI staining of Bifidobacterium thermophilum. This observation suggests that the antibiotic activity of the coprisin analogue may occur through specific membrane disruption of C. difficile. Thus, these results indicate that the coprisin analogue may prove useful as a therapeutic agent for C. difficile infection-associated inflammatory diarrhea and pseudomembranous colitis. PMID:21807975

  16. Protective Role of Nuclear Factor E2-Related Factor 2 against Acute Oxidative Stress-Induced Pancreatic β -Cell Damage.

    PubMed

    Fu, Jingqi; Zheng, Hongzhi; Wang, Huihui; Yang, Bei; Zhao, Rui; Lu, Chunwei; Liu, Zhiyuan; Hou, Yongyong; Xu, Yuanyuan; Zhang, Qiang; Qu, Weidong; Pi, Jingbo

    2015-01-01

    Oxidative stress is implicated in the pathogenesis of pancreatic β-cell dysfunction that occurs in both type 1 and type 2 diabetes. Nuclear factor E2-related factor 2 (NRF2) is a master regulator in the cellular adaptive response to oxidative stress. The present study found that MIN6 β-cells with stable knockdown of Nrf2 (Nrf2-KD) and islets isolated from Nrf2-knockout mice expressed substantially reduced levels of antioxidant enzymes in response to a variety of stressors. In scramble MIN6 cells or wild-type islets, acute exposure to oxidative stressors, including hydrogen peroxide (H2O2) and S-nitroso-N-acetylpenicillamine, resulted in cell damage as determined by decrease in cell viability, reduced ATP content, morphology changes of islets, and/or alterations of apoptotic biomarkers in a concentration- and/or time-dependent manner. In contrast, silencing of Nrf2 sensitized MIN6 cells or islets to the damage. In addition, pretreatment of MIN6 β-cells with NRF2 activators, including CDDO-Im, dimethyl fumarate (DMF), and tert-butylhydroquinone (tBHQ), protected the cells from high levels of H2O2-induced cell damage. Given that reactive oxygen species (ROS) are involved in regulating glucose-stimulated insulin secretion (GSIS) and persistent activation of NRF2 blunts glucose-triggered ROS signaling and GSIS, the present study highlights the distinct roles that NRF2 may play in pancreatic β-cell dysfunction that occurs in different stages of diabetes. PMID:25949772

  17. Comparative study of the damage produced by acute ethanol and acetaldehyde treatment in a human fetal hepatic cell line.

    PubMed

    Olivares, I P; Bucio, L; Souza, V; Cárabez, A; Gutiérrez-Ruiz, M C

    1997-06-27

    The effects of acute ethanol and acetaldehyde treatment on cell proliferation, cell adhesion capacity, neutral red incorporation into lysosomes, glutathione content, protein sulfhydryl compounds, lipid peroxidation, inner mitochondrial membrane integrity (MTT test), lactate dehydrogenase activity (LDH) and ultrastructural alterations were investigated in a human fetal hepatic cell line (WRL-68 cells). WRL-68 cells were used, due to the fact that, although this cell line expresses some hepatic characteristics, it does not express alcohol dehydrogenase or cytochrome P450 activity, so it could be a good model to study the effect of the toxic agents per se. Cells were exposed during 120 min with 200 mM ethanol or 10 mM acetaldehyde. Under these conditions, cells presented 100% viability and no morphological alteration was observed by light microscopy. Acetaldehyde-treated cells reduced their proliferative capacity drastically while the ethanol-treated ones presented no difference with control cells. Cell adhesion to substrate, measured as time required to adhere to the substrate and time required to detach from the substrate, was diminished in acetaldehyde WRL-68-treated cells. Cytotoxicity measures as neutral red and MTT test showed that acetaldehyde-treated cells presented more damage than ethanol-treated ones. Cellular respiratory capacity was compromised by acetaldehyde treatment due to 40% less oxygen consumption than control cells. Lipid peroxidation values, measured as malondialdehyde production, were higher in ethanol-treated WRL-68 cells (127%) than in acetaldehyde-treated ones (60%) to control cell values. Lactate dehydrogenase activity (LDH) in extracellular media of ethanol-treated cells presented the highest values. GSH content was reduced 95% and thiol protein content was diminished severely in acetaldehyde-treated cells. Transmission electron microscopy showed more ultrastructural alterations in cells treated with acetaldehyde. The results indicate that

  18. Acute systemic DNA damage in youth does not impair immune defense with aging.

    PubMed

    Pugh, Jason L; Foster, Sarah A; Sukhina, Alona S; Petravic, Janka; Uhrlaub, Jennifer L; Padilla-Torres, Jose; Hayashi, Tomonori; Nakachi, Kei; Smithey, Megan J; Nikolich-Žugich, Janko

    2016-08-01

    Aging-related decline in immunity is believed to be the main driver behind decreased vaccine efficacy and reduced resistance to infections in older adults. Unrepaired DNA damage is known to precipitate cellular senescence, which was hypothesized to be the underlying cause of certain age-related phenotypes. Consistent with this, some hallmarks of immune aging were more prevalent in individuals exposed to whole-body irradiation (WBI), which leaves no anatomical repository of undamaged hematopoietic cells. To decisively test whether and to what extent WBI in youth will leave a mark on the immune system as it ages, we exposed young male C57BL/6 mice to sublethal WBI (0.5-4 Gy), mimicking human survivor exposure during nuclear catastrophe. We followed lymphocyte homeostasis thorough the lifespan, response to vaccination, and ability to resist lethal viral challenge in the old age. None of the irradiated groups showed significant differences compared with mock-irradiated (0 Gy) animals for the parameters measured. Even the mice that received the highest dose of sublethal WBI in youth (4 Gy) exhibited equilibrated lymphocyte homeostasis, robust T- and B-cell responses to live attenuated West Nile virus (WNV) vaccine and full survival following vaccination upon lethal WNV challenge. Therefore, a single dose of nonlethal WBI in youth, resulting in widespread DNA damage and repopulation stress in hematopoietic cells, leaves no significant trace of increased immune aging in a lethal vaccine challenge model. PMID:27072188

  19. Effect of repeated ('binge') dosing of MDMA to rats housed at normal and high temperature on neurotoxic damage to cerebral 5-HT and dopamine neurones.

    PubMed

    Sanchez, Veronica; O'shea, Esther; Saadat, Kathryn S; Elliott, J Martin; Colado, M Isabel; Green, A Richard

    2004-09-01

    The technique of 'binge' dosing (several doses in one session) by recreational users of 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) requires evaluation in terms of its consequences on the acute hyperthermic response and long-term neurotoxicity. We examined the neurotoxic effects of this dosing schedule on 5-HT and dopamine neurones in the rat brain. When repeated (three) doses of MDMA (2, 4 and 6 mg/kg i.p.) were given 3 h apart to rats housed at 19 degrees C, a dose-dependent acute hyperthermia and long-term loss of 5-HT was observed in several brain regions (hippocampus, cortex and striatum), with an approximate 50% loss following 3 x 4 mg/kg and 65% decrease following 3 x 6 mg/kg. No decrease in striatal dopamine content was detected. When MDMA (4 mg/kg i.p.) was given repeatedly to rats housed at 30 degrees C, a larger acute hyperthermic response than that observed in rats treated at 19 degrees C environment was seen (maximum response 2.6 +/- 0.1 degrees C versus 1.3 +/- 0.2 degrees C). A long-term cerebral 5-HT loss of approximately 65% was also detected in both the cortex and hippocampus, but no loss in striatal dopamine content occurred. These data emphasize the increased acute hyperthermic response and neurotoxicity which occurs when MDMA is administered in a hot room environment compared to normal room temperature conditions, and support the view that MDMA is a selective 5-HT neurotoxin, even when a binge dosing schedule is employed and the rats are present in a hot environment. PMID:15358986

  20. Effect of endurance training on seizure susceptibility, behavioral changes and neuronal damage after kainate-induced status epilepticus in spontaneously hypertensive rats.

    PubMed

    Tchekalarova, J; Shishmanova, M; Atanasova, D; Stefanova, M; Alova, L; Lazarov, N; Georgieva, K

    2015-11-01

    The therapeutic efficacy of regular physical exercises in an animal model of epilepsy and depression comorbidity has been confirmed previously. In the present study, we examined the effects of endurance training on susceptibility to kainate (KA)-induced status epilepticus (SE), behavioral changes and neuronal damage in spontaneously hypertensive rats (SHRs). Male SHRs were randomly divided into two groups. One group was exercised on a treadmill with submaximal loading for four weeks and the other group was sedentary. Immediately after the training period, SE was evoked in half of the sedentary and trained rats by KA, while the other half of the two groups received saline. Basal systolic (SP), diastolic (DP) and mean arterial pressure (MAP) of all rats were measured at the beginning and at the end of the training period. Anxiety, memory and depression-like behaviour were evaluated a month after SE. The release of 5-HT in the hippocampus was measured using a liquid scintillation method and neuronal damage was analyzed by hematoxylin and eosin staining. SP and MAP of exercised SHRs decreased in comparison with the initial values. The increased resistance of SHRs to KA-induced SE was accompanied by an elongated latent seizure-free period, improved object recognition memory and antidepressant effect after the training program. While the anticonvulsant and positive behavioral effects of endurance training were accompanied by an increase of 5-HT release in the hippocampus, it did not exert neuroprotective activity. Our results indicate that prior exercise is an effective means to attenuate KA-induced seizures and comorbid behavioral changes in a model of hypertension and epilepsy suggesting a potential influence of hippocampal 5-HT on a comorbid depression. However, this beneficial impact does not prevent the development of epilepsy and concomitant brain damage. PMID:26319691

  1. SK channel activation modulates mitochondrial respiration and attenuates neuronal HT-22 cell damage induced by H2O2.

    PubMed

    Richter, Maren; Nickel, Catharina; Apel, Lisa; Kaas, Alexander; Dodel, Richard; Culmsee, Carsten; Dolga, Amalia M

    2015-02-01

    Previous studies established an essential role for small conductance calcium-activated potassium (SK) channels in neuronal cell death pathways induced by glutamate excitotoxicity in cortical neurons in vitro and after cerebral ischemia in vivo. In addition to the intracellular calcium deregulation, glutamate-induced cell death also involves mechanisms of oxidative stress and mitochondrial dysfunction. Therefore, we sought to investigate whether SK channel activation might also affect mechanisms of intrinsic death pathways induced by reactive oxygen species (ROS) such as hydrogen peroxide (H2O2). Exposure of immortalized hippocampal HT-22 cells to H2O2 imposed activation of a cascade of intracellular toxic events resulting in intracellular ROS production, mitochondrial loss of function, and ultimately cell death. Using a pharmacological approach to activate SK channels with CyPPA, we demonstrated a reduction of H2O2-mediated intracellular ROS production and cell death. Interestingly, CyPPA mediated neuroprotection in conditions of extracellular calcium and/or pyruvate depletion, pointing to a neuroprotective role of mitochondrial SK channels. Moreover, CyPPA partially inhibited H2O2-induced mitochondrial superoxide production, but did not prevent mitochondrial membrane depolarization. CyPPA treatment resulted in slight ATP depletion and a reduction of mitochondrial respiration/oxygen consumption. These findings postulate that SK channels mediate a protective effect by preventing neuronal death from subsequent oxidative stress through an adaptive metabolic response at the level of mitochondria. Therefore, SK channel activation may serve as a therapeutic target, where mitochondrial dysfunction and related mechanisms of oxidative stress contribute to progressive degeneration and death of neurons. PMID:25576183

  2. Excitotoxic Insult Results in a Long-Lasting Activation of CaMKIIα and Mitochondrial Damage in Living Hippocampal Neurons

    PubMed Central

    Otmakhov, Nikolai; Gorbacheva, Elena V.; Regmi, Shaurav; Yasuda, Ryohei; Hudmon, Andy; Lisman, John

    2015-01-01

    Over-activation of excitatory NMDA receptors and the resulting Ca2+ overload is the main cause of neuronal toxicity during stroke. CaMKII becomes misregulated during such events. Biochemical studies show either a dramatic loss of CaMKII activity or its persistent autonomous activation after stroke, with both of these processes being implicated in cell toxicity. To complement the biochemical data, we monitored CaMKII activation in living hippocampal neurons in slice cultures using high spatial/temporal resolution two-photon imaging of the CaMKIIα FRET sensor, Camui. CaMKII activation state was estimated by measuring Camui fluorescence lifetime. Short NMDA insult resulted in Camui activation followed by a redistribution of its protein localization: an increase in spines, a decrease in dendritic shafts, and concentration into numerous clusters in the cell soma. Camui activation was either persistent (> 1–3 hours) or transient (~20 min) and, in general, correlated with its protein redistribution. After longer NMDA insult, however, Camui redistribution persisted longer than its activation, suggesting distinct regulation/phases of these processes. Mutational and pharmacological analysis suggested that persistent Camui activation was due to prolonged Ca2+ elevation, with little impact of autonomous states produced by T286 autophosphorylation and/or by C280/M281 oxidation. Cell injury was monitored using expressible mitochondrial marker mito-dsRed. Shortly after Camui activation and clustering, NMDA treatment resulted in mitochondrial swelling, with persistence of the swelling temporarily linked to the persistence of Camui activation. The results suggest that in living neurons excitotoxic insult produces long-lasting Ca2+-dependent active state of CaMKII temporarily linked to cell injury. CaMKII function, however, is to be restricted due to strong clustering. The study provides the first characterization of CaMKII activation dynamics in living neurons during excitotoxic

  3. Acute and chronic cocaine differentially alter the subcellular distribution of AMPA GluR1 subunits in region-specific neurons within the mouse ventral tegmental area

    PubMed Central

    Lane, D.A.; Jaferi, A.; Kreek, M.J.; Pickel, V.M.

    2010-01-01

    Cocaine administration increases AMPA GluR1 expression and receptor-mediated activation of the ventral tegmental area (VTA). Functionality is determined, however, by surface availability of these receptors in transmitter- and VTA-region-specific neurons, which may also be affected by cocaine. To test this hypothesis, we used electron microscopic immunolabeling of AMPA GluR1 subunits and tyrosine hydroxylase (TH; the enzyme needed for dopamine synthesis), in the cortical-associated parabrachial (PB) and in the limbic-associated paranigral (PN) VTA of adult male C57BL/6 mice receiving either a single injection (acute) or repeated escalating-doses for 14 days (chronic) of cocaine. Acute cocaine resulted in opposing VTA-region-specific changes in TH-containing dopaminergic dendrites. TH-labeled dendrites within the PB VTA showed increased cytoplasmic GluR1 immunogold particle density consistent with decreased AMPA receptor-mediated glutamatergic transmission. Conversely, TH-labeled dendrites within the PN VTA showed greater surface expression of GluR1 with increases in both synaptic and plasmalemmal GluR1 immunogold density after a single injection of cocaine. These changes diminished in both VTA subregions after chronic cocaine administration. In contrast, non-TH-containing (presumably GABAergic) dendrites showed VTA-region-specific changes only after repeated cocaine administration such that synaptic GluR1 decreased in the PB, but increased in the PN VTA. Taken together, these findings provide ultrastructural evidence suggesting that chronic cocaine not only reverses the respective depression and facilitation of mesocortical (PB) and mesolimbic (PN) dopaminergic neurons elicited by acute cocaine, but also differentially affects synaptic availability of these receptors in non-dopaminergic neurons of each region. These adaptations may contribute to increased cocaine seeking/relapse and decreased reward that is reported with chronic cocaine use. PMID:20553819

  4. Subchronic Polychlorinated Biphenyl (Aroclor 1254) Exposure Produces Oxidative Damage and Neuronal Death of Ventral Midbrain Dopaminergic Systems

    PubMed Central

    Lee, Donna W.; Notter, Sarah A.; Thiruchelvam, Mona; Dever, Daniel P.; Fitzpatrick, Richard; Kostyniak, Paul J.; Cory-Slechta, Deborah A.; Opanashuk, Lisa A.

    2012-01-01

    Recent epidemiologic studies have demonstrated a link between organochlorine and pesticide exposure to an enhanced risk for neurodegenerative disorders such as Parkinson’s disease (PD). A common biological phenomenon underlying cell injury associated with both polychlorinated biphenyl (PCB) exposure and dopaminergic neurodegeneration during aging is oxidative stress (OS). In this study, we tested the hypothesis that oral PCB exposure, via food ingestion, impairs dopamine systems in the adult murine brain. We determined whether PCB exposure was associated with OS in dopaminergic neurons, a population of cells that selectively degenerate in PD. After 4 weeks of oral exposure to the PCB mixture Aroclor 1254, several congeners, mostly ortho substituted, accumulated throughout the brain. Significant increases in locomotor activity were observed within 2 weeks, which persisted after cessation of PCB exposure. Stereologic analyses revealed a significant loss of dopaminergic neurons within the substantia nigra and ventral tegmental area. However, striatal dopamine levels were elevated, suggesting that compensatory mechanisms exist to maintain dopamine homeostasis, which could contribute to the observed increases in locomotor activity following PCB exposure. Biochemical experiments revealed alterations in OS markers, including increases in SOD and HO-1 levels and the presence of oxidatively modified lipids and proteins. These findings were accompanied by elevated iron levels within the striatal and midbrain regions, perhaps due to the observed dysregulation of transferrin receptors and ferritin levels following PCB exposure. In this study, we suggest that both OS and the uncoupling of iron regulation contribute to dopamine neuron degeneration and hyperactivity following PCB exposure. PMID:22094459

  5. The cardiac surgery-associated neutrophil gelatinase-associated lipocalin (CSA-NGAL) score: A potential tool to monitor acute tubular damage.

    PubMed

    de Geus, Hilde R H; Ronco, Claudio; Haase, Michael; Jacob, Laurent; Lewington, Andrew; Vincent, Jean-Louis

    2016-06-01

    Acute kidney injury (AKI), defined as a rise in serum creatinine (functional AKI), is a frequent complication after cardiac surgery. The expression pattern of acute tubular damage biomarkers such as neutrophil gelatinase-associated lipocalin (NGAL) has been shown to precede functional AKI and, therefore, may be useful to identify very early tubular damage. The term subclinical AKI represents acute tubular damage in the absence of functional AKI (biomarker positivity without a rise in serum creatinine) and affects hard outcome measures. This potentiates an tubular-damage-based identification of renal injury, which may guide clinical management, allowing for very early preventive-protective strategies. The aim of this paper was to review the current available evidence on NGAL applicability in adult cardiac surgery patients and combine this knowledge with the expert consensus of the authors to generate an NGAL based tubular damage score: The cardiac surgery-associated NGAL Score (CSA-NGAL score). The CSA-NGAL score might be the tool needed to improve awareness and enable interventions to possibly modify these detrimental outcomes. In boldly doing so, it is intended to introduce a different approach in study designs, which will undoubtedly expand our knowledge and will hopefully move the AKI biomarker field forward. PMID:26952930

  6. Absence of acute ocular damage in humans after prolonged exposure to intense RF EMF.

    PubMed

    Adibzadeh, F; van Rhoon, G C; Verduijn, G M; Naus-Postema, N C; Paulides, M M

    2016-01-21

    The eye is considered to be a critical organ when determining safety standards for radio frequency (RF) radiation. Experimental data obtained using animals showed that RF heating of the eye, particularly over a specific threshold, can induce cataracts. During the treatment of cancer in the head and neck by hyperthermia, the eyes receive a considerable dose of RF radiation due to stray radiation from the prolonged (60 min) and intense exposure at 434 MHz of this region. In the current study, we verified the exposure guidelines for humans by determining the association between the electromagnetic and thermal dose in the eyes with the reported ocular effects. We performed a simulation study to retrospectively assess the specific absorption rate (SAR) and temperature increase in the eyes of 16 selected patients (encompassing a total of 74 treatment sessions) whose treatment involved high power delivery as well as a minimal distance between the tumor site and the eye. Our results show that the basic restrictions on the peak 10 g spatial-averaged SAR (10 W kg(-1)) and peak tissue temperature increase (1 °C) are exceeded by up to 10.4 and 4.6 times, on average, and by at least 6.2 and 1.8 times when considering the lower limit of the 95% confidence interval. Evaluation of the acute effects according to patients' feedback (all patients), the common toxicity criteria scores (all patients) and an ophthalmology investigation (one patient with the highest exposure) revealed no indication of any serious acute ocular effect, even though the eyes were exposed to high electromagnetic fields, leading to a high thermal dose. We also found that, although there is a strong correlation (R (2) =  0.88) between the predicted induced SAR and temperature in the eye, there are large uncertainties regarding the temperature-SAR relationship. Given this large uncertainty (129%) compared with the uncertainty of 3D temperature simulations (61%), we recommend using temperature simulations as a

  7. Absence of acute ocular damage in humans after prolonged exposure to intense RF EMF

    NASA Astrophysics Data System (ADS)

    Adibzadeh, F.; van Rhoon, G. C.; Verduijn, G. M.; Naus-Postema, N. C.; Paulides, M. M.

    2016-01-01

    The eye is considered to be a critical organ when determining safety standards for radio frequency (RF) radiation. Experimental data obtained using animals showed that RF heating of the eye, particularly over a specific threshold, can induce cataracts. During the treatment of cancer in the head and neck by hyperthermia, the eyes receive a considerable dose of RF radiation due to stray radiation from the prolonged (60 min) and intense exposure at 434 MHz of this region. In the current study, we verified the exposure guidelines for humans by determining the association between the electromagnetic and thermal dose in the eyes with the reported ocular effects. We performed a simulation study to retrospectively assess the specific absorption rate (SAR) and temperature increase in the eyes of 16 selected patients (encompassing a total of 74 treatment sessions) whose treatment involved high power delivery as well as a minimal distance between the tumor site and the eye. Our results show that the basic restrictions on the peak 10 g spatial-averaged SAR (10 W kg-1) and peak tissue temperature increase (1 °C) are exceeded by up to 10.4 and 4.6 times, on average, and by at least 6.2 and 1.8 times when considering the lower limit of the 95% confidence interval. Evaluation of the acute effects according to patients’ feedback (all patients), the common toxicity criteria scores (all patients) and an ophthalmology investigation (one patient with the highest exposure) revealed no indication of any serious acute ocular effect, even though the eyes were exposed to high electromagnetic fields, leading to a high thermal dose. We also found that, although there is a strong correlation (R 2  =  0.88) between the predicted induced SAR and temperature in the eye, there are large uncertainties regarding the temperature-SAR relationship. Given this large uncertainty (129%) compared with the uncertainty of 3D temperature simulations (61%), we recommend using temperature

  8. Metallothionein blocks oxidative DNA damage induced by acute inorganic arsenic exposure

    SciTech Connect

    Qu, Wei Waalkes, Michael P.

    2015-02-01

    We studied how protein metallothionein (MT) impacts arsenic-induced oxidative DNA damage (ODD) using cells that poorly express MT (MT-I/II double knockout embryonic cells; called MT-null cells) and wild-type (WT) MT competent cells. Arsenic (as NaAsO{sub 2}) was less cytolethal over 24 h in WT cells (LC{sub 50} = 11.0 ± 1.3 μM; mean ± SEM) than in MT-null cells (LC{sub 50} = 5.6 ± 1.2 μM). ODD was measured by the immuno-spin trapping method. Arsenic (1 or 5 μM; 24 h) induced much less ODD in WT cells (121% and 141% of control, respectively) than in MT-null cells (202% and 260%). In WT cells arsenic caused concentration-dependent increases in MT expression (transcript and protein), and in the metal-responsive transcription factor-1 (MTF-1), which is required to induce the MT gene. In contrast, basal MT levels were not detectable in MT-null cells and unaltered by arsenic exposure. Transfection of MT-I gene into the MT-null cells markedly reduced arsenic-induced ODD levels. The transport genes, Abcc1 and Abcc2 were increased by arsenic in WT cells but either showed no or very limited increases in MT-null cells. Arsenic caused increases in oxidant stress defense genes HO-1 and GSTα2 in both WT and MT-null cells, but to much higher levels in WT cells. WT cells appear more adept at activating metal transport systems and oxidant response genes, although the role of MT in these responses is unclear. Overall, MT protects against arsenic-induced ODD in MT competent cells by potential sequestration of scavenging oxidant radicals and/or arsenic. - Highlights: • Metallothionein blocks arsenic toxicity. • Metallothionein reduces arsenic-induced DNA damage. • Metallothionein may bind arsenic or radicals produced by arsenic.

  9. Chronic Intermittent Ethanol Exposure Enhances the Excitability and Synaptic Plasticity of Lateral Orbitofrontal Cortex Neurons and Induces a Tolerance to the Acute Inhibitory Actions of Ethanol.

    PubMed

    Nimitvilai, Sudarat; Lopez, Marcelo F; Mulholland, Patrick J; Woodward, John J

    2016-03-01

    Alcoholism is associated with changes in brain reward and control systems, including the prefrontal cortex. In prefrontal areas, the orbitofrontal cortex (OFC) has been suggested to have an important role in the development of alcohol-abuse disorders and studies from this laboratory demonstrate that OFC-mediated behaviors are impaired in alcohol-dependent animals. However, it is not known whether chronic alcohol (ethanol) exposure alters the fundamental properties of OFC neurons. In this study, mice were exposed to repeated cycles of chronic intermittent ethanol (CIE) exposure to induce dependence and whole-cell patch-clamp electrophysiology was used to examine the effects of CIE treatment on lateral OFC (lOFC) neuron excitability, synaptic transmission, and plasticity. Repeated cycles of CIE exposure and withdrawal enhanced current-evoked action potential (AP) spiking and this was accompanied by a reduction in the after-hyperpolarization and a decrease in the functional activity of SK channels. CIE mice also showed an increase in the AMPA/NMDA ratio, and this was associated with an increase in GluA1/GluA2 AMPA receptor expression and a decrease in GluN2B NMDA receptor subunits. Following CIE treatment, lOFC neurons displayed a persistent long-term potentiation of glutamatergic synaptic transmission following a spike-timing-dependent protocol. Lastly, CIE treatment diminished the inhibitory effect of acute ethanol on AP spiking of lOFC neurons and reduced expression of the GlyT1 transporter. Taken together, these results suggest that chronic exposure to ethanol leads to enhanced intrinsic excitability and glutamatergic synaptic signaling of lOFC neurons. These alterations may contribute to the impairment of OFC-dependent behaviors in alcohol-dependent individuals. PMID:26286839

  10. HDAC6 Regulates the Chaperone-Mediated Autophagy to Prevent Oxidative Damage in Injured Neurons after Experimental Spinal Cord Injury

    PubMed Central

    Su, Min; Guan, Huaqing; Zhang, Fan; Gao, Yarong; Teng, Xiaomei; Yang, Weixin

    2016-01-01

    Hypoxia-ischemia- (HI-) induced oxidative stress plays a role in secondary pathocellular processes of acute spinal cord injury (SCI) due to HI from many kinds of mechanical trauma. Increasing evidence suggests that the histone deacetylase-6 (HDAC6) plays an important role in cell homeostasis in both physiological and abnormal, stressful, pathological conditions. This paper found that inhibition of HDAC6 accelerated reactive oxygen species (ROS) generation and cell apoptosis in response to the HI. Deficiency of HDAC6 hindered the chaperone-mediated autophagy (CMA) activity to resistance of HI-induced oxidative stress. Furthermore, this study provided the experimental evidence for the potential role of HDAC6 in the regulation of CMA by affecting HSP90 acetylation. Therefore, HDAC6 plays an important role in the function of CMA pathway under the HI stress induced by SCI and it may be a potential therapeutic target in acute SCI model. PMID:26649145

  11. Effects of glycerol on human skin damaged by acute sodium lauryl sulphate treatment.

    PubMed

    Atrux-Tallau, Nicolas; Romagny, Céline; Padois, Karine; Denis, Alain; Haftek, Marek; Falson, Françoise; Pirot, Fabrice; Maibach, Howard I

    2010-08-01

    Glycerol, widely used as humectant, is known to protect against irritants and to accelerate recovery of irritated skin. However, most studies were done with topical formulations (i.e. emulsions) containing glycerol in relatively high amounts, preventing drawing conclusions from direct effects. In this study, acute chemical irritations were performed on the forearm with application of a 10% sodium lauryl sulphate (SLS) aqueous solution under occlusion for 3 h. Then, glycerol aqueous solutions from 1 to 10% were applied under occlusion for 3 h. After elimination of moist excess consecutive to occlusive condition, in ambient air for 15 and 30 min, skin barrier function was investigated by dual measurement of skin hydration and transepidermal water loss (TEWL). Treatments with SLS solution under occlusion significantly increased TEWL and decreased skin hydration as assessed by capacitance measurements. The SLS irritant property was raised by the occlusion and the water barrier function as well as water content appeared impaired. Recovery with glycerol at low doses was remarkable through a mechanism that implies its hygroscopic properties and which is saturable. This precocious effect acts through skin rehydration by enhancing water-holding capacity of stratum corneum that would facilitate the late physiological repair of impaired skin barrier. Thus, glycerol appears to substitute for natural moisturizing factors that have been washed out by the detergent action of SLS, enhancing skin hydration but without restoring skin barrier function as depicted by TEWL values that remained high. Thus, irritant contact dermatitis treated with glycerol application compensate for skin dehydration, favouring physiological process to restore water barrier function of the impaired skin. Empirical use of glycerol added topical formulations onto detergent altered skin was substantiated in the present physicochemical approach. PMID:20043170

  12. Improved clinicopathologic assessments of acute liver damage due to trauma in Indian ring-necked parakeets (Psittacula krameri manillensis).

    PubMed

    Williams, Susan M; Holthaus, Lisa; Barron, Heather Wilson; Divers, Stephen J; McBride, Michael; Almy, Frederic; Bush, Sharon; Latimer, Kenneth S

    2012-06-01

    Increased activities of certain biochemical enzymes (alanine aminotransferase [ALT], aspartate aminotransferase [AST], lactate dehydrogenase [LDH], alkaline phosphatase [ALP]) have been associated with blunt liver injury in many species. To evaluate changes in plasma hepatic biochemical parameters in acute avian liver disease caused by trauma and to compare biochemical changes with histologic lesions in hepatic parenchyma, 30 healthy fasted Indian ring-necked parakeets (Psittacula krameri manillensis) were divided into 2 groups, and traumatic liver injury was caused by endoscopic liver biopsy (group 1) or by liver biopsy and crushing injury to the hepatic parenchyma with endoscopic forceps (group 2) in anesthetized birds. Blood samples were collected at baseline and at 12, 24, 36, 48, 60, 72, 84, 96, 108, and 120 hours in alternate groups to compare analyte values after injury with those at baseline. Results showed consistently decreased plasma ALP activity (excluding 1 time point) throughout the study, which was thought to be associated with isoflurane administration. Plasma glutamate dehydrogenase activity initially increased but rapidly declined thereafter and was attributed to acute focal hepatocellular injury. In both groups, increases in plasma AST, ALT, and LDH activities was most likely caused by muscle injury because creatine kinase activity was concurrently increased. Compared with baseline values, bile acid concentration and y-glutamyl transferase activity were not affected by liver biopsy or crush injury. Plasma sorbitol dehydrogenase activity was the most specific indicator of liver injury in both groups. Histologic changes correlated poorly with biochemical results, possibly because the small area of hepatic parenchyma that was damaged did not affect enzyme values substantially. PMID:22872978

  13. Global Sensitivity Analysis of a Mathematical Model of Acute Inflammation Identifies Nonlinear Dependence of Cumulative Tissue Damage on Host Interleukin-6 Responses

    PubMed Central

    Mathew, Shibin; Bartels, John; Banerjee, Ipsita; Vodovotz, Yoram

    2014-01-01

    The precise inflammatory role of the cytokine interleukin (IL)-6 and its utility as a biomarker or therapeutic target have been the source of much debate, presumably due to the complex pro- and anti-inflammatory effects of this cytokine. We previously developed a nonlinear ordinary differential equation (ODE) model to explain the dynamics of endotoxin (lipopolysaccharide; LPS)-induced acute inflammation and associated whole-animal damage/dysfunction (a proxy for the health of the organism), along with the inflammatory mediators tumor necrosis factor (TNF)-α, IL-6, IL-10, and nitric oxide (NO). The model was partially calibrated using data from endotoxemic C57Bl/6 mice. Herein, we investigated the sensitivity of the area under the damage curve (AUCD) to the 51 rate parameters of the ODE model for different levels of simulated LPS challenges using a global sensitivity approach called Random Sampling High Dimensional Model Representation (RS-HDMR). We explored sufficient parametric Monte Carlo samples to generate the variance-based Sobol' global sensitivity indices, and found that inflammatory damage was highly sensitive to the parameters affecting the activity of IL-6 during the different stages of acute inflammation. The AUCIL6 showed a bimodal distribution, with the lower peak representing healthy response and the higher peak representing sustained inflammation. Damage was minimal at low AUCIL6, giving rise to a healthy response. In contrast, intermediate levels of AUCIL6 resulted in high damage, and this was due to the insufficiency of damage recovery driven by anti-inflammatory responses and the activation of positive feedback sustained by IL-6. At high AUCIL6, damage recovery was interestingly restored in some population of simulated animals due to the NO-mediated anti-inflammatory responses. These observations suggest that the host's health status during acute inflammation depends in a nonlinear fashion on the magnitude of the inflammatory stimulus, on the

  14. Preventing neuronal damage and inflammation in vivo during cortical microelectrode implantation through the use of Poloxamer P-188

    NASA Astrophysics Data System (ADS)

    Misra, A.; Kondaveeti, P.; Nissanov, J.; Barbee, K.; Shewokis, P.; Rioux, L.; Moxon, K. A.

    2013-02-01

    Objective. The aim of this study was to test the efficacy of Poloxamer P188 to reduce cell death and immune response associated with mechanical trauma to cells during implantation of a chronic recording electrode. Approach. Ceramic multi-site recording electrodes were implanted bilaterally into 15 adult male Long-Evans rats. One of each pair was randomly assigned to receive a coating of Poloxamer while the other was treated with saline. The extent of neuron loss, and glial cell recruitment were characterized at 2, 4 and 6 weeks post-implantation by stereologic analysis. Main results. At 2 and 4 weeks post-implantation, Poloxamer-coated implants showed significantly fewer glial cells and more neurons in the peri-electrode space than controls; however, this significance was lost by 6 weeks. Significance. These findings are the first to suggest that Poloxamer has neuroprotective effects in vivo; however, at a fixed loading dose, these effects are limited to approximately 1 month post-implantation.

  15. Valeriana officinalis Extracts Ameliorate Neuronal Damage by Suppressing Lipid Peroxidation in the Gerbil Hippocampus Following Transient Cerebral Ischemia.

    PubMed

    Yoo, Dae Young; Jung, Hyo Young; Nam, Sung Min; Kim, Jong Whi; Choi, Jung Hoon; Kwak, Youn-Gil; Yoo, Miyoung; Lee, Sanghee; Yoon, Yeo Sung; Hwang, In Koo

    2015-06-01

    As a medicinal plant, the roots of Valeriana officinalis have been used as a sedative and tranquilizer. In the present study, we evaluated the neuroprotective effects of valerian root extracts (VE) on the hippocampal CA1 region of gerbils after 5 min of transient cerebral ischemia. Gerbils were administered VE orally once a day for 3 weeks, subjected to ischemia/reperfusion injury, and continued on VE for 3 weeks. The administration of 100 mg/kg VE (VE100 group) significantly reduced the ischemia-induced spontaneous motor hyperactivity 1 day after ischemia/reperfusion. Four days after ischemia/reperfusion, animals treated with VE showed abundant cresyl violet-positive neurons in the hippocampal CA1 region when compared to the vehicle or 25 mg/kg VE-treated groups. In addition, the VE treatment markedly decreased microglial activation in the hippocampal CA1 region 4 days after ischemia. Compared to the other groups, the VE100 group showed the lowest level of lipid peroxidation during the first 24 h after ischemia/reperfusion. In summary, the findings in this study suggest that pretreatment with VE has protective effects against ischemic injury in the hippocampal pyramidal neurons by decreasing microglial activation and lipid peroxidation. PMID:25785762

  16. NEURON-SPECIFIC PHOSPHOPROTEINS AS BIOCHEMICAL INDICATORS OF NEUROTOXICITY: EFFECTS OF ACUTE ADMINISTRATION OF TRIMETHYLTIN TO THE ADULT RAT

    EPA Science Inventory

    The cytoarchitecture of the adult central nervous system is expressed by proteins specific to individual cell types. In this investigation, a subclass of these proteins, the neuron-specific phosphoproteins, was examined after the administration of trimethyltin (TMT), a neurotoxic...

  17. Autophagy in acute brain injury.

    PubMed

    Galluzzi, Lorenzo; Bravo-San Pedro, José Manuel; Blomgren, Klas; Kroemer, Guido

    2016-08-01

    Autophagy is an evolutionarily ancient mechanism that ensures the lysosomal degradation of old, supernumerary or ectopic cytoplasmic entities. Most eukaryotic cells, including neurons, rely on proficient autophagic responses for the maintenance of homeostasis in response to stress. Accordingly, autophagy mediates neuroprotective effects following some forms of acute brain damage, including methamphetamine intoxication, spinal cord injury and subarachnoid haemorrhage. In some other circumstances, however, the autophagic machinery precipitates a peculiar form of cell death (known as autosis) that contributes to the aetiology of other types of acute brain damage, such as neonatal asphyxia. Here, we dissect the context-specific impact of autophagy on non-infectious acute brain injury, emphasizing the possible therapeutic application of pharmacological activators and inhibitors of this catabolic process for neuroprotection. PMID:27256553

  18. Combined damage to entorhinal cortex and cholinergic basal forebrain neurons, two early neurodegenerative features accompanying Alzheimer's disease: effects on locomotor activity and memory functions in rats.

    PubMed

    Traissard, Natalia; Herbeaux, Karine; Cosquer, Brigitte; Jeltsch, Hélène; Ferry, Barbara; Galani, Rodrigue; Pernon, Anne; Majchrzak, Monique; Cassel, Jean-Christophe

    2007-04-01

    In Alzheimer's disease (AD), cognitive decline is linked to cholinergic dysfunctions in the basal forebrain (BF), although the earliest neuronal damage is described in the entorhinal cortex (EC). In rats, selective cholinergic BF lesions or fiber-sparing EC lesions may induce memory deficits, but most often of weak magnitude. This study investigated, in adult rats, the effects on activity and memory of both lesions, alone or in combination, using 192 IgG-saporin (OX7-saporin as a control) and L-N-methyl-D-aspartate to destroy BF and EC neurons, respectively. Rats were tested for locomotor activity in their home cage and for working- and/or reference-memory in various tasks (water maze, Hebb-Williams maze, radial maze). Only rats with combined lesions showed diurnal and nocturnal hyperactivity. EC lesions impaired working memory and induced anterograde memory deficits in almost all tasks. Lesions of BF cholinergic neurons induced more limited deficits: reference memory was impaired in the probe trial of the water-maze task and in the radial maze. When both lesions were combined, performance never improved in the water maze and the number of errors in the Hebb-Williams and the radial mazes was always larger than in any other group. These results (i) indicate synergistic implications of BF and EC in memory function, (ii) suggest that combined BF cholinergic and fiber-sparing EC lesions may model aspects of anterograde memory deficits and restlessness as seen in AD, (iii) challenge the cholinergic hypothesis of cognitive dysfunctions in AD, and (iv) contribute to open theoretical views on AD-related memory dysfunctions going beyond the latter hypothesis. PMID:16760925

  19. Flaxseed Mitigates Acute Oxidative Lung Damage in a Mouse Model of Repeated Radiation and Hyperoxia Exposure Associated with Space Exploration

    PubMed Central

    Pietrofesa, Ralph A.; Solomides, Charalambos C.; Christofidou-Solomidou, Melpo

    2015-01-01

    Background Spaceflight missions may require crewmembers to conduct extravehicular activities (EVA). Pre-breathe protocols in preparation for an EVA entail 100% hyperoxia exposure that may last for a few hours and be repeated 2-3 times weekly. Each EVA is associated with additional challenges such as low levels of total body cosmic/galactic radiation exposure that may present a threat to crewmember health. We have developed a mouse model of total body radiation and hyperoxia exposure and identified acute damage of lung tissues. In the current study we evaluated the usefulness of dietary flaxseed (FS) as a countermeasure agent for such double-hit exposures. Methods We evaluated lung tissue changes 2 weeks post-initiation of exposure challenges. Mouse cohorts (n=5/group) were pre-fed diets containing either 0% FS or 10% FS for 3 weeks and exposed to: a) normoxia (Untreated); b) >95% O2 (O2); c) 0.25Gy single fraction gamma radiation (IR); or d) a combination of O2 and IR (O2+IR) 3 times per week for 2 consecutive weeks, where 8-hour hyperoxia treatments were spanned by normoxic intervals. Results At 2 weeks post challenge, while control-diet fed mice developed significant lung injury and inflammation across all challenges, FS protected lung tissues by decreasing bronchoalveolar lavage fluid (BALF) neutrophils (p<0.003) and protein levels, oxidative tissue damage, as determined by levels of malondialdehyde (MDA) (p<0.008) and nitrosative stress as determined by nitrite levels. Lung hydroxyproline levels, a measure of lung fibrosis, were significantly elevated in mice fed 0% FS (p<0.01) and exposed to hyperoxia/radiation or the combination treatment, but not in FS-fed mice. FS also decreased levels of a pro-inflammatory, pro-fibrogenic cytokine (TGF-β1) gene expression levels in lung. Conclusion Flaxseed mitigated adverse effects in lung of repeat exposures to radiation/hyperoxia. This data will provide useful information in the design of countermeasures to early

  20. TNF-mediated damage to glomerular endothelium is an important determinant of acute kidney injury in sepsis.

    PubMed

    Xu, Chang; Chang, Anthony; Hack, Bradley K; Eadon, Michael T; Alper, Seth L; Cunningham, Patrick N

    2014-01-01

    Severe sepsis is often accompanied by acute kidney injury (AKI) and albuminuria. Here we studied whether the AKI and albuminuria associated with lipopolysaccharide (LPS) treatment in mice reflects impairment of the glomerular endothelium with its associated endothelial surface layer. LPS treatment decreased the abundance of endothelial surface layer heparan sulfate proteoglycans and sialic acid, and led to albuminuria likely reflecting altered glomerular filtration permselectivity. LPS treatment decreased the glomerular filtration rate (GFR), while also causing significant ultrastructural alterations in the glomerular endothelium. The density of glomerular endothelial cell fenestrae was 5-fold lower, whereas the average fenestrae diameter was 3-fold higher in LPS-treated than in control mice. The effects of LPS on the glomerular endothelial surface layer, endothelial cell fenestrae, GFR, and albuminuria were diminished in TNF receptor 1 (TNFR1) knockout mice, suggesting that these LPS effects are mediated by TNF-α activation of TNFR1. Indeed, intravenous administration of TNF decreased GFR and led to loss of glomerular endothelial cell fenestrae, increased fenestrae diameter, and damage to the glomerular endothelial surface layer. LPS treatment decreased kidney expression of vascular endothelial growth factor (VEGF). Thus, our findings confirm the important role of glomerular endothelial injury, possibly by a decreased VEGF level, in the development and progression of AKI and albuminuria in the LPS model of sepsis in the mouse. PMID:23903370

  1. Differential Effects of Pharmacologic and Genetic Modulation of NMDA Receptor Activity on HIV/gp120-Induced Neuronal Damage in an In Vivo Mouse Model

    PubMed Central

    Nakanishi, Nobuki; Kang, Yeon-Joo; Tu, Shichun; McKercher, Scott R.; Masliah, Eliezer; Lipton, Stuart A.

    2015-01-01

    HIV-associated neurocognitive disorder (HAND) consists of motor and cognitive dysfunction in a relatively large percentage of patients with AIDS. Prior work has suggested that at least part of the neuronal and synaptic damage observed in HAND may occur due to excessive stimulation of NMDA-type glutamate receptors (NMDARs). Here, we compared pharmacological and genetic manipulation of NMDAR activity using an improved derivative of the NMDAR antagonist memantine, termed NitroMemantine, and the modulatory NMDAR subunit GluN3A in the HIV/gp120 transgenic (tg) mouse model of HAND. Interestingly, we found that while both NitroMemantine and GluN3A have been shown to inhibit NMDAR activity, NitroMemantine protected synapses in gp120 tg mice, but overexpression of GluN3A augmented the damage. Given recent findings in the field, one explanation for this apparently paradoxical result is the location of the NMDARs primarily affected, with NitroMemantine inhibiting predominantly extrasynaptic pathologically-activated NMDARs, but GluN3A disrupting normal NMDAR-mediated neuroprotective activity via inhibition of synaptic NMDARs. PMID:26374431

  2. Neurokinin B Causes Acute GnRH Secretion and Repression of GnRH Transcription in GT1–7 GnRH Neurons

    PubMed Central

    Glidewell-Kenney, Christine A.; Shao, Paul P.; Iyer, Anita K.; Grove, Anna M. H.; Meadows, Jason D.

    2013-01-01

    Genetic studies in human patients with idiopathic hypogonadotropic hypogonadism (IHH) identified mutations in the genes that encode neurokinin B (NKB) and the neurokinin 3 receptor (NK3R). However, determining the mechanism whereby NKB regulates gonadotropin secretion has been difficult because of conflicting results from in vivo studies investigating the luteinizing hormone (LH) response to senktide, a NK3R agonist. NK3R is expressed in a subset of GnRH neurons and in kisspeptin neurons that are known to regulate GnRH secretion. Thus, one potential source of inconsistency is that NKB could produce opposing direct and indirect effects on GnRH secretion. Here, we employ the GT1-7 cell model to elucidate the direct effects of NKB on GnRH neuron function. We find that GT1-7 cells express NK3R and respond to acute senktide treatment with c-Fos induction and increased GnRH secretion. In contrast, long-term senktide treatment decreased GnRH secretion. Next, we focus on the examination of the mechanism underlying the long-term decrease in secretion and determine that senktide treatment represses transcription of GnRH. We further show that this repression of GnRH transcription may involve enhanced c-Fos protein binding at novel activator protein-1 (AP-1) half-sites identified in enhancer 1 and the promoter, as well as chromatin remodeling at the promoter of the GnRH gene. These data indicate that NKB could directly regulate secretion from NK3R-expressing GnRH neurons. Furthermore, whether the response is inhibitory or stimulatory toward GnRH secretion could depend on the history or length of exposure to NKB because of a repressive effect on GnRH transcription. PMID:23393128

  3. Acute Seizures in Old Age Leads to a Greater Loss of CA1 Pyramidal Neurons, an Increased Propensity for Developing Chronic TLE and a Severe Cognitive Dysfunction.

    PubMed

    Hattiangady, Bharathi; Kuruba, Ramkumar; Shetty, Ashok K

    2011-02-01

    The aged population displays an enhanced risk for developing acute seizure (AS) activity. However, it is unclear whether AS activity in old age would result in a greater magnitude of hippocampal neurodegeneration and inflammation, and an increased predilection for developing chronic temporal lobe epilepsy (TLE) and cognitive dysfunction. Therefore, we addressed these issues in young-adult (5-months old) and aged (22-months old) F344 rats after three-hours of AS activity, induced through graded intraperitoneal injections of kainic acid (KA), and terminated through a diazepam injection. During the three-hours of AS activity, both young adult and aged groups exhibited similar numbers of stage-V motor seizures but the numbers of stage-IV motor seizures were greater in the aged group. In both age groups, three-hour AS activity induced degeneration of 50-55% of neurons in the dentate hilus, 22-32% of neurons in the granule cell layer and 49-52% neurons in the CA3 pyramidal cell layer without showing any interaction between the age and AS activity. However, degeneration of neurons in the CA1 pyramidal cell layer showed a clear interaction between the age and AS activity (12% in the young adult group and 56% in the aged group), suggesting that an advanced age makes the CA1 pyramidal neurons more susceptible to die with AS activity. The extent of inflammation measured through the numbers of activated microglial cells was similar between the two age groups. Interestingly, the predisposition for developing chronic TLE at 2-3 months after AS activity was 60% for young adult rats but 100% for aged rats. Moreover, both frequency & intensity of spontaneous recurrent seizures in the chronic phase after AS activity were 6-12 folds greater in aged rats than in young adult rats. Furthermore, aged rats lost their ability for spatial learning even in a scrupulous eleven-session water maze learning paradigm after AS activity, in divergence from young adult rats which retained the

  4. Effects of Cannabidiol and Hypothermia on Short-Term Brain Damage in New-Born Piglets after Acute Hypoxia-Ischemia.

    PubMed

    Lafuente, Hector; Pazos, Maria R; Alvarez, Antonia; Mohammed, Nagat; Santos, Martín; Arizti, Maialen; Alvarez, Francisco J; Martinez-Orgado, Jose A

    2016-01-01

    Hypothermia is a standard treatment for neonatal encephalopathy, but nearly 50% of treated infants have adverse outcomes. Pharmacological therapies can act through complementary mechanisms with hypothermia improving neuroprotection. Cannabidiol could be a good candidate. Our aim was to test whether immediate treatment with cannabidiol and hypothermia act through complementary brain pathways in hypoxic-ischemic newborn piglets. Hypoxic-ischemic animals were randomly divided into four groups receiving 30 min after the insult: (1) normothermia and vehicle administration; (2) normothermia and cannabidiol administration; (3) hypothermia and vehicle administration; and (4) hypothermia and cannabidiol administration. Six hours after treatment, brains were processed to quantify the number of damaged neurons by Nissl staining. Proton nuclear magnetic resonance spectra were obtained and analyzed for lactate, N-acetyl-aspartate and glutamate. Metabolite ratios were calculated to assess neuronal damage (lactate/N-acetyl-aspartate) and excitotoxicity (glutamate/Nacetyl-aspartate). Western blot studies were performed to quantify protein nitrosylation (oxidative stress), content of caspase-3 (apoptosis) and TNFα (inflammation). Individually, the hypothermia and the cannabidiol treatments reduced the glutamate/Nacetyl-aspartate ratio, as well as TNFα and oxidized protein levels in newborn piglets subjected to hypoxic-ischemic insult. Also, both therapies reduced the number of necrotic neurons and prevented an increase in lactate/N-acetyl-aspartate ratio. The combined effect of hypothermia and cannabidiol on excitotoxicity, inflammation and oxidative stress, and on cell damage, was greater than either hypothermia or cannabidiol alone. The present study demonstrated that cannabidiol and hypothermia act complementarily and show additive effects on the main factors leading to hypoxic-ischemic brain damage if applied shortly after the insult. PMID:27462203

  5. Effects of Cannabidiol and Hypothermia on Short-Term Brain Damage in New-Born Piglets after Acute Hypoxia-Ischemia

    PubMed Central

    Lafuente, Hector; Pazos, Maria R.; Alvarez, Antonia; Mohammed, Nagat; Santos, Martín; Arizti, Maialen; Alvarez, Francisco J.; Martinez-Orgado, Jose A.

    2016-01-01

    Hypothermia is a standard treatment for neonatal encephalopathy, but nearly 50% of treated infants have adverse outcomes. Pharmacological therapies can act through complementary mechanisms with hypothermia improving neuroprotection. Cannabidiol could be a good candidate. Our aim was to test whether immediate treatment with cannabidiol and hypothermia act through complementary brain pathways in hypoxic-ischemic newborn piglets. Hypoxic-ischemic animals were randomly divided into four groups receiving 30 min after the insult: (1) normothermia and vehicle administration; (2) normothermia and cannabidiol administration; (3) hypothermia and vehicle administration; and (4) hypothermia and cannabidiol administration. Six hours after treatment, brains were processed to quantify the number of damaged neurons by Nissl staining. Proton nuclear magnetic resonance spectra were obtained and analyzed for lactate, N-acetyl-aspartate and glutamate. Metabolite ratios were calculated to assess neuronal damage (lactate/N-acetyl-aspartate) and excitotoxicity (glutamate/Nacetyl-aspartate). Western blot studies were performed to quantify protein nitrosylation (oxidative stress), content of caspase-3 (apoptosis) and TNFα (inflammation). Individually, the hypothermia and the cannabidiol treatments reduced the glutamate/Nacetyl-aspartate ratio, as well as TNFα and oxidized protein levels in newborn piglets subjected to hypoxic-ischemic insult. Also, both therapies reduced the number of necrotic neurons and prevented an increase in lactate/N-acetyl-aspartate ratio. The combined effect of hypothermia and cannabidiol on excitotoxicity, inflammation and oxidative stress, and on cell damage, was greater than either hypothermia or cannabidiol alone. The present study demonstrated that cannabidiol and hypothermia act complementarily and show additive effects on the main factors leading to hypoxic-ischemic brain damage if applied shortly after the insult. PMID:27462203

  6. Gastroprotective Effect of Cochinchina momordica Seed Extract in Nonsteroidal Anti-Inflammatory Drug-Induced Acute Gastric Damage in a Rat Model

    PubMed Central

    Lim, Ji Hwan; Kim, Joo-Hyun; Lee, Byoung Hwan; Seo, Pyoung Ju; Kang, Jung Mook; Jo, So Young; Park, Ji Hyun; Nam, Ryoung Hee; Chang, Hyun; Kwon, Jin-Won; Lee, Dong Ho

    2014-01-01

    Background/Aims The major compounds of Cochinchina momordica seed extract (SK-MS10) include momordica saponins. We report that the gastroprotective effect of SK-MS10 in an ethanol-induced gastric damage rat model is mediated by suppressing proinflammatory cytokines and downregulating cytosolic phospholipase A2 (cPLA2), 5-lipoxygenase (5-LOX), and the activation of calcitonin gene-related peptide. In this study, we evaluated the gastroprotective effects of SK-MS10 in the nonsteroidal anti-inflammatory drug (NSAID)-induced gastric damage rat model. Methods The pretreatment effect of SK-MS10 was evaluated in the NSAID-induced gastric damage rat model using aspirin, indomethacin, and diclofenac in 7-week-old rats. Gastric damage was evaluated based on the gross ulcer index by gastroenterologists, and the damage area (%) was measured using the MetaMorph 7.0 video image analysis system. Myeloperoxidase (MPO) was measured by enzyme-linked immunosorbent assay, and Western blotting was used to analyze the levels of cyclooxygenase (COX)-1, COX-2, cPLA2, and 5-LOX. Results All NSAIDs induced gastric damage based on the gross ulcer index and damage area (p<0.05). Gastric damage was significantly attenuated by SK-MS10 pretreatment compared with NSAID treatment alone (p<0.05). The SK-MS10 pretreatment group exhibited lower MPO levels than the diclofenac group. The expression of cPLA2 and 5-LOX was decreased by SK-MS10 pretreatment in each of the three NSAID treatment groups. Conclusions SK-MS10 exhibited a gastroprotective effect against NSAID-induced acute gastric damage in rats. However, its protective mechanism may be different across the three types of NSAID-induced gastric damage models in rats. PMID:24516701

  7. Four types of inorganic nanoparticles stimulate the inflammatory reaction in brain microglia and damage neurons in vitro.

    PubMed

    Xue, Yang; Wu, Jie; Sun, Jiao

    2012-10-17

    Once nanoparticles enter the central nervous system (CNS), they immediately encounter a complex environment of resident microglial immune cell and neurons. In the present study, NPs of 20-60nm in diameter (SiO(2)-NPs, TiO(2)-NPs, HAP-NPs and Fe(3)O(4)-NPs) were evaluated for their ability to induce microglia-mediated neurodegeneration. The microglia were directly exposed to NPs. The results showed that both TiO(2)-NPs and HAP-NPs induced significant iNOS expression, resulting in NO release from the microglia. The expression levels of MCP-1 and MIP-1α were also upregulated. These activation effects were accompanied by the activation of the transcription factor NF-κB. In addition, the secretion levels of TNF-α, IL-1β and IL-6 were variably increased by all four NPs. Subsequently, the cell-free supernatants from microglia monocultures were harvested and tested for their ability to stimulate PC12 cells. The results demonstrated that microglia-derived soluble factors induced by TiO(2)-NPs suppressed Th gene expression, and those by TiO(2)-NPs and HAP-NPs caused cytotoxicity in PC12 cells. Taken together, these results suggest that the NPs induced microglial activation and subsequently caused the release of proinflammatory factors that contributed to the dysfunction and cytotoxicity in PC12 cells. PMID:22939914

  8. Damage to pancreatic acinar cells and preservation of islets of Langerhans in a rat model of acute pancreatitis induced by Karwinskia humboldtiana (buckthorn).

    PubMed

    Carcano-Diaz, Katya; Garcia-Garcia, Aracely; Segoviano-Ramirez, Juan Carlos; Rodriguez-Rocha, Humberto; Loera-Arias, Maria de Jesus; Garcia-Juarez, Jaime

    2016-09-01

    Karwinskia humboldtiana (Kh) is a poisonous plant that grows in some regions of the American continent. Consuming large amounts of Kh fruit results in acute intoxication leading to respiratory failure, culminating in death within days. There is evidence of histological damage to the lungs, liver, and kidneys following accidental and experimental Kh intoxication. To date, the microscopic effect of Kh consumption on the pancreas has not been described. We examined the early effects of Kh fruit on pancreatic tissue at different stages of acute intoxication in the Wistar rat. We found progressive damage confined to the exocrine pancreas, starting with a reduction in the number of zymogen granules, loss of acinar architecture, the presence of autophagy-like vesicles, apoptosis and inflammatory infiltrate. The pancreatic pathology culminated in damaged acini characterized by necrosis and edema, with a complete loss of lobular architecture. Interestingly, the morphology of the islets of Langerhans was conserved throughout our evaluations. Taken together, our results indicate the damage induced by a high dose of Kh fruit in the Wistar rat is consistent with an early acute necrotizing pancreatitis that exclusively affects the exocrine pancreas. Therefore, this system might be useful as an animal model to study the treatment of pancreatic diseases. More importantly, as the islets of Langerhans were preserved, the active compounds of Kh fruit could be utilized for the treatment of acinar pancreatic cancer. Further studies might provide insight into the severity of acute Kh intoxication in humans and influence the design of treatments for pancreatic diseases and acinar pancreatic cancer. PMID:26877198

  9. Patch-clamp recordings of rat neurons from acute brain slices of the somatosensory cortex during magnetic stimulation

    PubMed Central

    Pashut, Tamar; Magidov, Dafna; Ben-Porat, Hana; Wolfus, Shuki; Friedman, Alex; Perel, Eli; Lavidor, Michal; Bar-Gad, Izhar; Yeshurun, Yosef; Korngreen, Alon

    2014-01-01

    Although transcranial magnetic stimulation (TMS) is a popular tool for both basic research and clinical applications, its actions on nerve cells are only partially understood. We have previously predicted, using compartmental modeling, that magnetic stimulation of central nervous system neurons depolarized the soma followed by initiation of an action potential in the initial segment of the axon. The simulations also predict that neurons with low current threshold are more susceptible to magnetic stimulation. Here we tested these theoretical predictions by combining in vitro patch-clamp recordings from rat brain slices with magnetic stimulation and compartmental modeling. In agreement with the modeling, our recordings demonstrate the dependence of magnetic stimulation-triggered action potentials on the type and state of the neuron and its orientation within the magnetic field. Our results suggest that the observed effects of TMS are deeply rooted in the biophysical properties of single neurons in the central nervous system and provide a framework both for interpreting existing TMS data and developing new simulation-based tools and therapies. PMID:24917788

  10. Intrathecal infusion of BMAA induces selective motor neuron damage and astrogliosis in the ventral horn of the spinal cord

    PubMed Central

    Yin, Hong Z.; Yu, Stephen; Hsu, Cheng-I; Liu, Joe; Acab, Allan; Wu, Richard; Tao, Anna; Chiang, Benjamin J.; Weiss, John H.

    2014-01-01

    The neurotoxin beta-N-methylamino-L-alanine (BMAA) was first identified as a “toxin of interest” in regard to the amyotrophic lateral sclerosis–Parkinsonism Dementia Complex of Guam (ALS/PDC); studies in recent years highlighting widespread environmental sources of BMAA exposure and providing new clues to toxic mechanisms have suggested possible relevance to sporadic ALS as well. However, despite clear evidence of uptake into tissues and a range of toxic effects in cells and animals, an animal model in which BMAA induces a neurodegenerative picture resembling ALS is lacking, possibly in part reflecting limited understanding of critical factors pertaining to its absorption, biodistribution and metabolism. To bypass some of these issues and ensure delivery to a key site of disease pathology, we examined effects of prolonged (30 day) intrathecal infusion in wild type (WT) rats, and rats harboring the familial ALS associated G93A SOD1 mutation, over an age range (80±2 to 110±2 days) during which the G93A rats are developing disease pathology yet remain asymptomatic. The BMAA exposures induced changes that in many ways resembles those seen in the G93A rats, with degenerative changes in ventral horn motor neurons (MNs) with relatively little dorsal horn pathology, marked ventral horn astrogliosis and increased 3-nitrotyrosine labeling in and surrounding MNs, a loss of labeling for the astrocytic glutamate transporter, GLT-1, surrounding MNs, and mild accumulation and aggregation of TDP-43 in the cytosol of some injured and degenerating MNs. Thus, prolonged intrathecal infusion of BMAA can reproduce a picture in spinal cord incorporating many of the pathological hallmarks of diverse forms of human ALS, including substantial restriction of overt pathological changes to the ventral horn, consistent with the possibility that environmental BMAA exposure could be a risk factor and/or contributor to some human disease. PMID:24918341

  11. Intrathecal infusion of BMAA induces selective motor neuron damage and astrogliosis in the ventral horn of the spinal cord.

    PubMed

    Yin, Hong Z; Yu, Stephen; Hsu, Cheng-I; Liu, Joe; Acab, Allan; Wu, Richard; Tao, Anna; Chiang, Benjamin J; Weiss, John H

    2014-11-01

    The neurotoxin beta-N-methylamino-l-alanine (BMAA) was first identified as a "toxin of interest" in regard to the amyotrophic lateral sclerosis-Parkinsonism Dementia Complex of Guam (ALS/PDC); studies in recent years highlighting widespread environmental sources of BMAA exposure and providing new clues to toxic mechanisms have suggested possible relevance to sporadic ALS as well. However, despite clear evidence of uptake into tissues and a range of toxic effects in cells and animals, an animal model in which BMAA induces a neurodegenerative picture resembling ALS is lacking, possibly in part reflecting limited understanding of critical factors pertaining to its absorption, biodistribution and metabolism. To bypass some of these issues and ensure delivery to a key site of disease pathology, we examined effects of prolonged (30day) intrathecal infusion in wild type (WT) rats, and rats harboring the familial ALS associated G93A SOD1 mutation, over an age range (80±2 to 110±2days) during which the G93A rats are developing disease pathology yet remain asymptomatic. The BMAA exposures induced changes that in many ways resemble those seen in the G93A rats, with degenerative changes in ventral horn motor neurons (MNs) with relatively little dorsal horn pathology, marked ventral horn astrogliosis and increased 3-nitrotyrosine labeling in and surrounding MNs, a loss of labeling for the astrocytic glutamate transporter, GLT-1, surrounding MNs, and mild accumulation and aggregation of TDP-43 in the cytosol of some injured and degenerating MNs. Thus, prolonged intrathecal infusion of BMAA can reproduce a picture in spinal cord incorporating many of the pathological hallmarks of diverse forms of human ALS, including substantial restriction of overt pathological changes to the ventral horn, consistent with the possibility that environmental BMAA exposure could be a risk factor and/or contributor to some human disease. PMID:24918341

  12. Redox regulation of mitochondrial fission, protein misfolding, synaptic damage, and neuronal cell death: potential implications for Alzheimer’s and Parkinson’s diseases

    PubMed Central

    Nakamura, Tomohiro

    2010-01-01

    Normal mitochondrial dynamics consist of fission and fusion events giving rise to new mitochondria, a process termed mitochondrial biogenesis. However, several neurodegenerative disorders manifest aberrant mitochondrial dynamics, resulting in morphological abnormalities often associated with deficits in mitochondrial mobility and cell bioenergetics. Rarely, dysfunctional mitochondrial occur in a familial pattern due to genetic mutations, but much more commonly patients manifest sporadic forms of mitochondrial disability presumably related to a complex set of interactions of multiple genes (or their products) with environmental factors (G × E). Recent studies have shown that generation of excessive nitric oxide (NO), in part due to generation of oligomers of amyloid-β (Aβ) protein or overactivity of the NMDA-subtype of glutamate receptor, can augment mitochondrial fission, leading to frank fragmentation of the mitochondria. S-Nitrosylation, a covalent redox reaction of NO with specific protein thiol groups, represents one mechanism contributing to NO-induced mitochondrial fragmentation, bioenergetic failure, synaptic damage, and eventually neuronal apoptosis. Here, we summarize our evidence in Alzheimer’s disease (AD) patients and animal models showing that NO contributes to mitochondrial fragmentation via S-nitrosylation of dynamin-related protein 1 (Drp1), a protein involved in mitochondrial fission. These findings may provide a new target for drug development in AD. Additionally, we review emerging evidence that redox reactions triggered by excessive levels of NO can contribute to protein misfolding, the hallmark of a number of neurodegenerative disorders, including AD and Parkinson’s disease. For example, S-nitrosylation of parkin disrupts its E3 ubiquitin ligase activity, and thereby affects Lewy body formation and neuronal cell death. PMID:20177970

  13. Endothelial microparticles carrying hedgehog-interacting protein induce continuous endothelial damage in the pathogenesis of acute graft-versus-host disease.

    PubMed

    Nie, Di-Min; Wu, Qiu-Ling; Zheng, Peng; Chen, Ping; Zhang, Ran; Li, Bei-Bei; Fang, Jun; Xia, Ling-Hui; Hong, Mei

    2016-05-15

    Accumulating evidence suggests that endothelial microparticles (EMPs), a marker of endothelial damage, are elevated in acute graft-versus-host disease (aGVHD), and that endothelial damage is implicated in the pathogenesis of aGVHD, but the mechanisms remain elusive. In this study, we detected the plasma EMP levels and endothelial damage in patients and mice with aGVHD in vivo and then examined the effects of EMPs derived from injured endothelial cells (ECs) on endothelial damage and the role of hedgehog-interacting protein (HHIP) carried by EMPs in these effects in vitro. Our results showed that EMPs were persistently increased in the early posttransplantation phase in patients and mice with aGVHD. Meanwhile, endothelial damage was continuous in aGVHD mice, but was temporary in non-aGVHD mice after transplantation. In vitro, EMPs induced endothelial damage, including increased EC apoptosis, enhanced reactive oxygen species, decreased nitric oxide production and impaired angiogenic activity. Enhanced expression of HHIP, an antagonist for the Sonic hedgehog (SHH) signaling pathway, was observed in patients and mice with aGVHD and EMPs from injured ECs. The endothelial damage induced by EMPs was reversed when the HHIP incorporated into EMPs was silenced with an HHIP small interfering RNA or inhibited with the SHH pathway agonist, Smoothened agonist. This work supports a feasible vicious cycle in which EMPs generated during endothelial injury, in turn, aggravate endothelial damage by carrying HHIP into target ECs, contributing to the continuously deteriorating endothelial damage in the development of aGVHD. EMPs harboring HHIP would represent a potential therapeutic target for aGVHD. PMID:27009877

  14. DNA Repair Gene Polymorphisms and Their Relation With DNA Damage, DNA Repair, and Total Antioxidant Capacity in Childhood Acute Lymphoblastic Leukemia Survivors.

    PubMed

    Dincer, Yildiz; Yüksel, Selin; Batar, Bahadir; Güven, Mehmet; Onaran, Ilhan; Celkan, Tiraje

    2015-07-01

    Oxidative stress and defective DNA repair are major contributory factors in the initiation and progression of carcinogenesis. Chemotherapy and radiotherapy cause oxidative DNA damage, consume antioxidant capacity, and impair DNA repair activity. These effects of chemotherapy and radiotherapy may be contributory factors in the development of secondary malignancy in cancer survivors. Basal, H2O2-induced, and postrepair DNA damage; urinary 8-hydroxydeoxyguanosine level as a marker of oxidatively damaged DNA; and serum total antioxidant capacity were measured; XPD Lys751Gln, XRCC1 Arg399Gln, and XRCC1 Arg194Trp polymorphisms were analyzed in childhood acute lymphoblastic leukemia (ALL) survivors. Basal and H2O2-induced DNA damage were found to be higher in the ALL survivor group versus the control group, however, there was no significant difference between the other parameters. No association was found between the examined parameters and polymorphisms of XPD 751 and XRCC1 399 and both the groups. XRCC1 194Trp allele was found to be associated with a low level of postrepair DNA damage in the ALL survivors. In conclusion, basal DNA damage and susceptibility to oxidation are high in childhood ALL survivors. This situation which may easily lead to occurrence of a secondary cancer does not seem to be a result of deficient DNA repair. PMID:24577548

  15. Dopamine Modulates Spike Timing-Dependent Plasticity and Action Potential Properties in CA1 Pyramidal Neurons of Acute Rat Hippocampal Slices

    PubMed Central

    Edelmann, Elke; Lessmann, Volkmar

    2011-01-01

    Spike timing-dependent plasticity (STDP) is a cellular model of Hebbian synaptic plasticity which is believed to underlie memory formation. In an attempt to establish a STDP paradigm in CA1 of acute hippocampal slices from juvenile rats (P15–20), we found that changes in excitability resulting from different slice preparation protocols correlate with the success of STDP induction. Slice preparation with sucrose containing ACSF prolonged rise time, reduced frequency adaptation, and decreased latency of action potentials in CA1 pyramidal neurons compared to preparation in conventional ASCF, while other basal electrophysiological parameters remained unaffected. Whereas we observed prominent timing-dependent long-term potentiation (t-LTP) to 171 ± 10% of controls in conventional ACSF, STDP was absent in sucrose prepared slices. This sucrose-induced STDP deficit could not be rescued by stronger STDP paradigms, applying either more pre- and/or postsynaptic stimuli, or by a higher stimulation frequency. Importantly, slice preparation with sucrose containing ACSF did not eliminate theta-burst stimulation induced LTP in CA1 in field potential recordings in our rat hippocampal slices. Application of dopamine (for 10–20 min) to sucrose prepared slices completely rescued t-LTP and recovered action potential properties back to levels observed in ACSF prepared slices. Conversely, acute inhibition of D1 receptor signaling impaired t-LTP in ACSF prepared slices. No similar restoring effect for STDP as seen with dopamine was observed in response to the β-adrenergic agonist isoproterenol. ELISA measurements demonstrated a significant reduction of endogenous dopamine levels (to 61.9 ± 6.9% of ACSF values) in sucrose prepared slices. These results suggest that dopamine signaling is involved in regulating the efficiency to elicit STDP in CA1 pyramidal neurons. PMID:22065958

  16. Loss of extracellular superoxide dismutase leads to acute lung damage in the presence of ambient air: a potential mechanism underlying adult respiratory distress syndrome.

    PubMed

    Gongora, Maria Carolina; Lob, Heinrich E; Landmesser, Ulf; Guzik, Tomasz J; Martin, W David; Ozumi, Kiyoski; Wall, Susan M; Wilson, David Scott; Murthy, Niren; Gravanis, Michael; Fukai, Tohru; Harrison, David G

    2008-10-01

    The extracellular superoxide dismutase 3 (SOD3) is highly expressed in both blood vessels and lungs. In different models of pulmonary injury, SOD3 is reduced; however, it is unclear whether this contributes to lung injury. To study the role of acute SOD3 reduction in lung injury, the SOD3 gene was deleted in adult mice by using the Cre-Lox technology. Acute reduction of SOD3 led to a fivefold increase in lung superoxide, marked inflammatory cell infiltration, a threefold increase in the arterial-alveolar gradient, respiratory acidosis, histological changes similar to those observed in adult respiratory distress syndrome, and 85% mortality. Treatment with the SOD mimetic MnTBAP and intranasal administration of SOD-containing polyketal microparticles reduced mortality, prevented the histological alterations, and reduced lung superoxide levels. To understand how mice with the SOD3 embryonic deletion survived without lung injury, gene array analysis was performed. These data demonstrated the up-regulation of 37 genes and down-regulation of nine genes, including those involved in cell signaling, inflammation, and gene transcription in SOD3-/- mice compared with either mice with acute SOD3 reduction or wild-type controls. These studies show that SOD3 is essential for survival in the presence of ambient oxygen and that acute loss of this enzyme can lead to severe lung damage. Strategies either to prevent SOD3 inactivation or to augment its levels might prove useful in the treatment of acute lung injury. PMID:18787098

  17. Does acute, intense stimulation of oxytocin neurones in the supraoptic nucleus increase their content of oxytocin mRNA?

    PubMed

    Sumner, B E; Kawata, M; Russell, J A

    1989-06-12

    We investigated whether a sustained increase in oxytocin secretion, with or without enhanced electrical activity of the cell-bodies of oxytocin neurones, leads to a rapid increase in oxytocin mRNA content in these neurones. To stimulate oxytocin release, naloxone (2.5 mg/kg i.v. twice, 30 min apart) was given to urethane-anaesthetized female rats after intracerebroventricular (i.c.v.) morphine or vehicle infusion for 5 days; in the latter, naloxone acts on the neurohypophysis to increase oxytocin release without affecting the electrical activity of oxytocin neurone cell-bodies, but in the former, naloxone acts both on the neucohypophysis and on the cell-bodies to excite them electrically. Oxytocin content in peripheral plasma was measured intermittently by radioimmunoassay for 4 h after i.v. naloxone or vehicle, then the brain was removed and cryostat sections were cut through the supraoptic nucleus (SON). Oxytocin mRNA content in individual neurones (25-50 per rat) was measured semiquantitatively by in situ hybridisation histochemistry, using a tritiated synthetic cDNA 25-mer oligonucleotide probe, autoradiographical visualisation, and computer-assisted image-analysis to measure silver grain density. Nalaxone increased oxytocin content in plasma 7-fold for at least 40 min in i.c.v. vehicle-infused rats, and 40-fold for at least 40 min in i.c.v. morphine-infused rats. Naloxone had no significant effect on the oxytocin mRNA content in labelled cells in the SON, and no effect on the proportion of labelled cells, in either the i.c.v. morphine- or i.c.v. vehicle-infused rats.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2743158

  18. Effect of nor-trimebutine on neuronal activation induced by a noxious stimulus or an acute colonic inflammation in the rat.

    PubMed

    Sinniger, Valérie; Mouchet, Patrick; Bonaz, Bruno

    2005-10-21

    Nor-trimebutine is the main metabolite of trimebutine that is used in the treatment of patients with irritable bowel syndrome. Nor-trimebutine has a blocking activity on sodium channels and a potent local anesthetic effect. These properties were used to investigate the effect of nor-trimebutine on spinal neuronal activation induced by models of noxious somato-visceral stimulus and acute colonic inflammation. Nor-trimebutine was administered in rats either subcutaneously 30 min before intraperitoneal administration of acetic acid or intracolonically 30 min before intracolonic infusion of trinitrobenzenesulfonic acid. Abdominal contractions were counted for 1 h as a marker of abdominal pain. c-fos expression was used as a marker of neuronal activation and revealed by immunohistochemistry 1h after intraperitoneal acetic acid injection and 2 h after colonic inflammation. Nor-trimebutine decreased Fos expression in the thoraco-lumbar (peritoneal irritation) and lumbo-sacral (colonic inflammation) spinal cord in laminae I, IIo V, VII and X. This effect was also observed in the sacral parasympathetic nucleus after colonic inflammation. Nor-trimebutine induced a significant decrease of abdominal contractions following intraperitoneal acetic acid injection. These data may explain the effectiveness of trimebutine in the therapy of abdominal pain in the irritable bowel syndrome. PMID:15978629

  19. Effect of interaction between acute administration of morphine and cannabinoid compounds on spontaneous excitatory and inhibitory postsynaptic currents of magnocellular neurons of supraoptic nucleus

    PubMed Central

    Yousefpour, Mitra; Naderi, Nima; Motamedi, Fereshteh

    2016-01-01

    Objective(s): Opioids and cannabinoids are two important compounds that have been shown to influence the activity of magnocellular neurons (MCNs) of supraoptic nucleus (SON). The interaction between opioidergic and cannabinoidergic systems in various structures of the brain and spinal cord is now well established, but not in the MCNs of SON. Materials and methods: In this study, whole cell patch clamp recording of neurons in rat brain slice was used to investigate the effect of acute morphine and cannabinoid administration on spontaneous inhibitory and excitatory spostsynaptic currents (sIPSCs and sEPSCs) in MCNs. Results: Bath application of morphine produced an increase in sEPSCs frequency and a decrease in sIPSCs frequency. In contrast, bath application of URB597 (fatty acid amide hydrolase (FAAH) inhibitor) produced a decrease in sEPSCs frequency but an increase in sIPSCs frequency. WIN55212-2 (cannabinoid receptor agonist) decreased both sIPSCs and sEPSCs frequencies of MCNs. Co-application of morphine and URB597 attenuated the effect of morphine on MCNs. Conclusion: Taken together, these data indicated that at the cellular level, pharmacological augmentation of endocannabinoids could attenuate morphine effects on MCNs. PMID:27482350

  20. Effect of acute ethanol on beta-endorphin secretion from rat fetal hypothalamic neurons in primary cultures

    SciTech Connect

    Sarkar, D.K.; Minami, S. )

    1990-01-01

    To characterize the effect of ethanol on the hypothalamic {beta}-endorphin-containing neurons, rat fetal hypothalamic neurons were maintained in primary culture, and the secretion of {beta}-endorphin ({beta}-EP) was determined after ethanol challenges. Constant exposure to ethanol at doses of 6-50 mM produced a dose-dependent increase in basal secretion of {beta}-EP from these cultured cells. These doses of ethanol did not produce any significant effect on cell viability, DNA or protein content. The stimulated secretion of {beta}-EP following constant ethanol exposure is short-lasting. However, intermittent ethanol exposures maintained the ethanol stimulatory action on {beta}-EP secretion for a longer time. The magnitude of the {beta}-EP response to 50 mM ethanol is similar to that of the {beta}-EP response to 56 mM of potassium. Ethanol-stimulated {beta}-EP secretion required extracellular calcium and was blocked by a calcium channel blocker; a sodium channel blocker did not affect ethanol-stimulated secretion. These results suggest that the neuron culture system is a useful model for studying the cellular mechanisms involved in the ethanol-regulated hypothalamic opioid secretion.

  1. Effects of DHA-rich fish oil supplementation on the lipid profile, markers of muscle damage, and neutrophil function in wheelchair basketball athletes before and after acute exercise.

    PubMed

    Marques, Camila Garcia; Santos, Vinicius Coneglian; Levada-Pires, Adriana Cristina; Jacintho, Thiago Manzoni; Gorjão, Renata; Pithon-Curi, Tânia Cristina; Cury-Boaventura, Maria Fernanda

    2015-06-01

    We investigated the effects of docosahexaenoic acid (DHA)-rich fish oil (FO) supplementation on the lipid profile, levels of plasma inflammatory mediators, markers of muscle damage, and neutrophil function in wheelchair basketball players before and after acute exercise. We evaluated 8 male basketball wheelchair athletes before and after acute exercise both prior to (S0) and following (S1) FO supplementation. The subjects were supplemented with 3 g of FO daily for 30 days. The following components were measured: the plasma lipid profile (total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides), plasma inflammatory mediators (C-reactive protein, interleukin (IL)-1β, IL-1ra, IL-4, IL-6, IL-8, and tumor necrosis factor-α), markers of muscle damage (creatine kinase and lactate dehydrogenase (LDH)), and neutrophil function (cytokine production, phagocytic capacity, loss of membrane integrity, mitochondrial membrane potential, neutral lipid accumulation, phosphatidylserine externalization, DNA fragmentation, and production of reactive oxygen species (ROS)). Acute exercise increased the plasma levels of total cholesterol, LDH, IL1ra, and IL-6, led to the loss of membrane integrity, ROS production, and a high mitochondrial membrane potential in neutrophils, and reduced the phagocytic capacity and IL-6 production by the neutrophils (S0). However, supplementation prevented the increases in the plasma levels of LDH and IL-6, the loss of membrane integrity, and the alterations in ROS production and mitochondrial membrane potential in the neutrophils that were induced by exercise (S1). In conclusion, DHA-rich FO supplementation reduces the markers of muscle damage, inflammatory disturbances, and neutrophil death induced by acute exercise in wheelchair athletes. PMID:25942100

  2. Acute tianeptine treatment selectively modulates neuronal activation in the central nucleus of the amygdala and attenuates fear extinction.

    PubMed

    Godsil, B P; Bontempi, B; Mailliet, F; Delagrange, P; Spedding, M; Jay, T M

    2015-11-01

    Antidepressant drugs are commonly prescribed treatments for anxiety disorders, and there is growing interest in understanding how these drugs impact fear extinction because extinction learning is pivotal to successful exposure-based therapy (EBT). A key objective within this domain is understanding how antidepressants alter the activation of specific elements of the limbic-based network that governs such fear processing. Chronic treatment with the antidepressant tianeptine has been shown to reduce the acquisition of extinction learning in rats, yet the drug's acute influence on activation in prefrontal and amygdalar regions, and on extinction learning are not well understood. To assess its influence on cellular activation, rats were injected with tianeptine and Fos immunoreactivity was measured in these regions. Acute tianeptine treatment selectively altered Fos expression within subdivisions of the central nucleus of the amygdala (CEA) in a bidirectional manner that varied in relation to ongoing activation within the capsular subdivision and its prefrontal and intra-amygdalar inputs. This pattern of results suggests that the drug can conditionally modulate the activation of CEA subdivisions, which contain microcircuits strongly implicated in fear processing. The effect of acute tianeptine was also examined with respect to the acquisition, consolidation and expression of fear extinction in rats. Acute tianeptine attenuated extinction learning as well as the recall of extinction memory, which underscores that acute dosing with the drug could alter learning during EBT. Together these findings provide a new perspective for understanding the mechanism supporting tianeptine's clinical efficacy, as well as its potential influence on CEA-based learning mechanisms. PMID:25560759

  3. Combined minocycline plus pyruvate treatment enhances effects of each agent to inhibit inflammation, oxidative damage, and neuronal loss in an excitotoxic animal model of Huntington's disease.

    PubMed

    Ryu, J K; Choi, H B; McLarnon, J G

    2006-09-15

    The combination effects of minocycline (MC), a second-generation tetracycline compound and pyruvate (PY), a glycolysis end metabolite with antioxidant activity were investigated in the rat striatum following an excitotoxic insult. Striatal injection of quinolinic acid (QUIN) resulted in marked inflammation characterized by microgliosis, astrogliosis and enhanced expressions of pro-inflammatory enzymes inducible nitric oxide synthase and cyclooxygenase-2. Inflammatory responses were attenuated with administration of either MC or PY, however, the combination of both compounds was significantly more effective in reducing inflammation relative to MC or PY applied alone. Immunohistochemical analysis at 7 days post-intrastriatal QUIN injection showed extensive oxidative stress evident as lipid peroxidation, oxidative DNA damage and reactive oxygen species formation which was partially decreased by each agent applied separately but markedly inhibited with the combination of the two compounds. In addition, combination treatments significantly reduced neuronal loss in QUIN-injected striatum compared with the agents applied separately. Furthermore, long-term combination treatment decreased striatal lesions and inflammation after QUIN injection. These results demonstrate that MC and PY confer a considerably enhanced anti-inflammatory and neuroprotective efficacy when applied together and suggest this combinatorial procedure as a novel therapeutic strategy in neurodegenerative disorders such as Huntington's disease which exhibit excitotoxic insults. PMID:16809003

  4. Prophylactic treatment with melatonin after status epilepticus: effects on epileptogenesis, neuronal damage, and behavioral changes in a kainate model of temporal lobe epilepsy.

    PubMed

    Tchekalarova, Jana; Petkova, Zlatina; Pechlivanova, Daniela; Moyanova, Slavianka; Kortenska, Lidia; Mitreva, Rumiana; Lozanov, Valentin; Atanasova, Dimitrina; Lazarov, Nikolai; Stoynev, Alexander

    2013-04-01

    Melatonin is a potent antioxidant which showed anticonvulsant activities both in experimental and clinical studies. In the present study, we examined the effect of melatonin treatment (10mg/kg/day, diluted in drinking water, 8 weeks) during epileptogenesis on the consequences of a kainate (KA)-induced status epilepticus (SE) in rats. Melatonin increased the latency in the appearance of spontaneous recurrent seizures (SRSs) and decreased their frequency only during the treatment period. The behavioral alterations associated with hyperactivity, depression-like behavior during the light phase, and deficits in hippocampus-dependent working memory were positively affected by melatonin treatment in rats with epilepsy. Melatonin reduced the neuronal damage in the CA1 area of the hippocampus and piriform cortex and recovered the decrease of hippocampal serotonin (5-HT) level in rats with epilepsy. Taken together, long-term melatonin treatment after SE was unable to suppress the development of epileptogenesis. However, it showed a potential in reducing some of the deleterious alterations that develop during the chronic epileptic state in a diurnal phase-dependent mode. PMID:23435277

  5. Amyloid-β peptide increases cell surface localization of α7 ACh receptor to protect neurons from amyloid β-induced damage.

    PubMed

    Jin, Yu; Tsuchiya, Ayako; Kanno, Takeshi; Nishizaki, Tomoyuki

    Amyloid-β peptide 1-42 (Aβ1-42) reduced PC-12 cell viability in a concentration (1-10 μM)- and treatment time (48-72 h)-dependent manner. Nicotine prevented Aβ1-42-induced PC-12 cell death, but conversely, the α7 ACh receptor antagonist α-bungarotoxin enhanced Aβ1-42-induced cell toxicity. Extracellularly applied Aβ1-42 significantly increased cell surface localization of α7 ACh receptor in PC-12 cells as compared with that for non-treated control cells. Cell surface localization of α7 ACh receptor in the brain of 5xFAD mouse, an animal model of Alzheimer's disease (AD), apparently increased in an age (1-12 months)-dependent manner in association with increased accumulation of Aβ1-42 in the plasma membrane component. Taken together, these results indicate that Aβ1-42 promotes translocation of α7 ACh receptor towards the cell surface and that α7 ACh receptor rescues neuronal cells from Aβ1-42-induced damage. PMID:26522221

  6. The Mammalian Brain in the Electromagnetic Fields Designed by Man with Special Reference to Blood-Brain Barrier Function, Neuronal Damage and Possible Physical Mechanisms

    NASA Astrophysics Data System (ADS)

    Salford, L. G.; Nittby, H.; Brun, A.; Grafström, G.; Malmgren, L.; Sommarin, M.; Eberhardt, J.; Widegren, B.; Persson, B. R.

    Life on earth was formed during billions of years, exposed to,and shaped by the original physical forces such as gravitation, cosmic irradiation, atmospheric electric fields and the terrestrial magnetism. The Schumann resonances at 7.4 Hz are an example of oscillations possibly important for life. The existing organisms are created to function in harmony with these forces. However, in the late 19th century mankind introduced the use of electricity, in the early 20th century long-wave radio and in the 1940-ies short-wave radio. High frequency RF was introduced in the 50-ies as FM and television and during the very last decades, microwaves of the modern communication society spread around the world. Today, however, one third of the world's population is owner of the microwave-producing mobile phones and an even larger number is exposed to the cordless RF emitting systems. To what extent are all living organisms affected by these, almost everywhere present radio freque ncy fields? And what will be the effects of many years of continuing exposure? Since 1988 our group has studied the effects upon the mammalian blood-brain barrier (BBB) in rats by non-thermal radio frequency electromagnetic fields (RF-EMF). These have been shown to cause significantly increased leakage of the rats' own blood albumin through the BBB of exposed rats, at energy levels of 1W/kg and below, as compared to non-exposed animals in a total series of about two thousand animals.-6)} One remarkable observation is the fact that the lowest energy levels, with whole-body average power densities below 10mW/kg, give rise to the most pronounced albumin leakage. If mobile communication, even at extremely low energy levels, causes the users' own albumin to leak out through the BBB, also other unwanted and toxic molecules in the blood, may leak into the brain tissue and concentrate in and damage the neurons and glial cells of the brain. In later studies we have shown that a 2-h exposure to GSM 915 MHz, at

  7. Sleep deprivation does not affect neuronal susceptibility to mild traumatic brain injury in the rat.

    PubMed

    Caron, Aimee M; Stephenson, Richard

    2015-01-01

    Mild and moderate traumatic brain injuries (TBIs) (and concussion) occur frequently as a result of falls, automobile accidents, and sporting activities, and are a major cause of acute and chronic disability. Fatigue and excessive sleepiness are associated with increased risk of accidents, but it is unknown whether prior sleep debt also affects the pathophysiological outcome of concussive injury. Using the "dark neuron" (DN) as a marker of reversible neuronal damage, we tested the hypothesis that acute (48 hours) total sleep deprivation (TSD) and chronic sleep restriction (CSR; 10 days, 6-hour sleep/day) affect DN formation following mild TBI in the rat. TSD and CSR were administered using a walking wheel apparatus. Mild TBI was administered under anesthesia using a weight-drop impact model, and the acute neuronal response was observed without recovery. DNs were detected using standard bright-field microscopy with toluidine blue stain following appropriate tissue fixation. DN density was low under home cage and sleep deprivation control conditions (respective median DN densities, 0.14% and 0.22% of neurons), and this was unaffected by TSD alone (0.1%). Mild TBI caused significantly higher DN densities (0.76%), and this was unchanged by preexisting acute or chronic sleep debt (TSD, 0.23%; CSR, 0.7%). Thus, although sleep debt may be predicted to increase the incidence of concussive injury, the present data suggest that sleep debt does not exacerbate the resulting neuronal damage. PMID:26124685

  8. Hypervolemia induces and potentiates lung damage after recruitment maneuver in a model of sepsis-induced acute lung injury

    PubMed Central

    2010-01-01

    Introduction Recruitment maneuvers (RMs) seem to be more effective in extrapulmonary acute lung injury (ALI), caused mainly by sepsis, than in pulmonary ALI. Nevertheless, the maintenance of adequate volemic status is particularly challenging in sepsis. Since the interaction between volemic status and RMs is not well established, we investigated the effects of RMs on lung and distal organs in the presence of hypovolemia, normovolemia, and hypervolemia in a model of extrapulmonary lung injury induced by sepsis. Methods ALI was induced by cecal ligation and puncture surgery in 66 Wistar rats. After 48 h, animals were anesthetized, mechanically ventilated and randomly assigned to 3 volemic status (n = 22/group): 1) hypovolemia induced by blood drainage at mean arterial pressure (MAP)≈70 mmHg; 2) normovolemia (MAP≈100 mmHg), and 3) hypervolemia with colloid administration to achieve a MAP≈130 mmHg. In each group, animals were further randomized to be recruited (CPAP = 40 cm H2O for 40 s) or not (NR) (n = 11/group), followed by 1 h of protective mechanical ventilation. Echocardiography, arterial blood gases, static lung elastance (Est,L), histology (light and electron microscopy), lung wet-to-dry (W/D) ratio, interleukin (IL)-6, IL-1β, caspase-3, type III procollagen (PCIII), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) mRNA expressions in lung tissue, as well as lung and distal organ epithelial cell apoptosis were analyzed. Results We observed that: 1) hypervolemia increased lung W/D ratio with impairment of oxygenation and Est,L, and was associated with alveolar and endothelial cell damage and increased IL-6, VCAM-1, and ICAM-1 mRNA expressions; and 2) RM reduced alveolar collapse independent of volemic status. In hypervolemic animals, RM improved oxygenation above the levels observed with the use of positive-end expiratory pressure (PEEP), but increased lung injury and led to higher inflammatory and fibrogenetic

  9. Neuroendocrine, metabolic, and immune functions during the acute phase response of inflammatory stress in monosodium L-glutamate-damaged, hyperadipose male rat.

    PubMed

    Castrogiovanni, Daniel; Gaillard, Rolf C; Giovambattista, Andrés; Spinedi, Eduardo

    2008-01-01

    In rats, neonatal treatment with monosodium L-glutamate (MSG) induces several metabolic and neuroendocrine abnormalities, which result in hyperadiposity. No data exist, however, regarding neuroendocrine, immune and metabolic responses to acute endotoxemia in the MSG-damaged rat. We studied the consequences of MSG treatment during the acute phase response of inflammatory stress. Neonatal male rats were treated with MSG or vehicle (controls, CTR) and studied at age 90 days. Pituitary, adrenal, adipo-insular axis, immune, metabolic and gonadal functions were explored before and up to 5 h after single sub-lethal i.p. injection of bacterial lipopolysaccharide (LPS; 150 microg/kg). Our results showed that, during the acute phase response of inflammatory stress in MSG rats: (1) the corticotrope-adrenal, leptin, insulin and triglyceride responses were higher than in CTR rats, (2) pro-inflammatory (TNFalpha) cytokine response was impaired and anti-inflammatory (IL-10) cytokine response was normal, and (3) changes in peripheral estradiol and testosterone levels after LPS varied as in CTR rats. These data indicate that metabolic and neroendocrine-immune functions are altered in MSG-damaged rats. Our study also suggests that the enhanced corticotrope-corticoadrenal activity in MSG animals could be responsible, at least in part, for the immune and metabolic derangements characterizing hypothalamic obesity. PMID:18382067

  10. Effects of aluminum chloride on sodium current, transient outward potassium current and delayed rectifier potassium current in acutely isolated rat hippocampal CA1 neurons.

    PubMed

    Zhang, Bo; Nie, Aifang; Bai, Wei; Meng, Ziqiang

    2004-09-01

    The effects of aluminum chloride (AlCl3) on sodium current (INa), the transient outward potassium (IA) and delayed rectifier potassium currents (IK) in hippocampal CA1 neurons of rats were studied using the whole cell patch-clamp technique. AlCl3 decreased INa, IA, and IK in a partly reversible, dose and voltage-dependent manner. AlCl3 prolonged the time to peak of INa, and increased the inactivation time constants of INa and IA . In addition, 1000 microM AlCl3 shifted the voltage dependence of steady-state activation of INa, IA and IK toward positive potential, and the voltage dependence of steady-state inactivation of INa, IA toward negative potential. These results imply that AlCl3 could affect the activation and inactivation courses of sodium current and potassium current of rat hippocampal CA1 neurons, which may contribute to damage of the central nervous system by aluminum. PMID:15234075

  11. The role of multifunctional drug therapy against carbamate induced neuronal toxicity during acute and chronic phase in rats.

    PubMed

    Chahal, Karan Singh; Prakash, Atish; Majeed, Abu Bakar Abdul

    2015-07-01

    The current study has been designed to examine the effect of multifunctional drug therapy on carbofuran induced acute (2.187 mg/kg, s.c.) and sub-acute (0.2187 mg/kg, s.c.) neurotoxicity in male wistar rats. Drug treatment which includes nimodipine (Ca(2+) channel blocker), diazepam, ropinirole (dopamine agonist) and GSPE (antioxidant) was started 2h after carbofuran administration. Morris water maze was employed for aiming spatial memory. Narrow beam walk and rotarod were employed for testing motor functions. Brain acetylcholinesterase activity, thiobarbituric acid reactive species, nitrite, reduced glutathione, catalase levels, and mitochondrial complexes were also estimated. Carbofuran treatment resulted in significant development of cognitive and motor functions manifested as impairment in learning and memory along with increased thiobarbituric acid reactive species, nitrite levels and decreased acetylcholinesterase activity, reduced glutathione, catalase levels, and mitochondrial complexes. The standard antidote therapy (atropine) was not able to provide neuroprotection but was able to provide symptomatic relief. The multifunctional drug therapy attenuated carbofuran induced cognitive and motor dysfunction, acetylcholinesterase activity and other biochemical parameters. The triple combination in sub-acute study may be avoided in future as two drug combinations provide adequate neuroprotection. Thus it can be concluded that standard antidotal therapy may not provide neuroprotection while the multifunctional drug therapy offers neuroprotection against carbofuran and may dramatically increase survival and life quality. PMID:26151868

  12. Role of CCR5 and its ligands in the control of vascular inflammation and leukocyte recruitment required for acute excitotoxic seizure induction and neural damage.

    PubMed

    Louboutin, Jean-Pierre; Chekmasova, Alena; Marusich, Elena; Agrawal, Lokesh; Strayer, David S

    2011-02-01

    Chemokines may play a role in leukocyte migration across the blood-brain barrier (BBB) during neuroinflammation and other neuropathological processes, such as epilepsy. We investigated the role of the chemokine receptor CCR5 in seizures. We used a rat model based on intraperitoneal kainic acid (KA) administration. Four months before KA injection, adult rats were given femoral intramarrow inoculations of SV (RNAiR5-RevM10.AU1), which carries an interfering RNA (RNAi) against CCR5, plus a marker epitope (AU1), or its monofunctional RNAi-carrying homologue, SV(RNAiR5). This treatment lowered expression of CCR5 in circulating cells. In control rats, seizures induced elevated expression of CCR5 ligands MIP-1α and RANTES in the microvasculature, increased BBB leakage and CCR5(+) cells, as well as neuronal loss, inflammation, and gliosis in the hippocampi. Animals given either the bifunctional or the monofunctional vector were largely protected from KA-induced seizures, neuroinflammation, BBB damage, and neuron loss. Brain CCR5 mRNA was reduced. Rats receiving RNAiR5-bearing vectors showed far greater repair responses: increased neuronal proliferation, and decreased production of MIP-1α and RANTES. Controls received unrelated SV(BUGT) vectors. Decrease in CCR5 in circulating cells strongly protected from excitotoxin-induced seizures, BBB leakage, CNS injury, and inflammation, and facilitated neurogenic repair. PMID:20940264

  13. Astroglial U87 Cells Protect Neuronal SH-SY5Y Cells from Indirect Effect of Radiation by Reducing DNA Damage and Inhibiting Fas Mediated Apoptotic Pathway in Coculture System.

    PubMed

    Saeed, Yasmeen; Rehman, Abdul; Xie, Bingjie; Xu, Jin; Hong, Ma; Hong, Qing; Deng, Yulin

    2015-08-01

    Recent studies provide the evidence that indirect effects of radiation could lead to neuronal cells death but underlying mechanism is not completely understood. On the other hand astroglial cells are known to protect neuronal cells against stress conditions in vivo and invitro. Yet, the fate of neuronal cells and the neuroprotective effect of coculture system (with glial cells) in response to indirect radiation exposure remain rarely discussed. Here, we purpose that the indirect effect of radiation may induce DNA damage by cell cycle arrest and receptor mediated apoptotic cascade which lead to apoptotic death of neuronal SH-SY5Y cells. We also hypothesized that coculture (with glial U87) may relieved the neuronal SH-SY5Y cells from toxicity of indirect effects radiation by reducing DNA damage and expression of apoptotic proteins in vitro. In the present study irradiated cell conditioned medium (ICCM) was used as source of indirect effect of radiation. Neuronal SH-SY5Y cells were exposed to ICCM with and without coculture with (glial U87) in transwell coculture system respectively. Various endpoints such as, cell survival number assay, Annexin V/PI assay, cell cycle analysis by flow cytometer, mRNA level of Fas receptor by q RT-PCR, expression of key apoptotic proteins by western blot and estimation of neurotrophic factors by ELISA method were analyzed into neuronal SH-SY5Y cells with and without co culture after ICCM exposure respectively. We found that ICCM induced DNA damage in neuronal SH-SY5Y cells by significant increase in cell cycle arrest at S-phase (***P < 0.001) which was further supported by over expression of P53 protein (**P < 0.01). While coculture (with glial U87), significantly reduced the ICCM induced cell cycle arrest and expression of P53 ((###) P < 0.001) neuronal SH-SY5Y cells. Further investigation of the underlying apoptotic mechanism revealed that in coculture system; ICCM induced elevated level of FAS mRNA level was significantly reduced

  14. Microglial Contact Prevents Excess Depolarization and Rescues Neurons from Excitotoxicity123

    PubMed Central

    Kato, Go; Wake, Hiroaki; Akiyoshi, Ryohei; Miyamoto, Akiko; Eto, Kei; Ishikawa, Tatsuya; Moorhouse, Andrew J.

    2016-01-01

    Abstract Microglia survey and directly contact neurons in both healthy and damaged brain, but the mechanisms and functional consequences of these contacts are not yet fully elucidated. Combining two-photon imaging and patch clamping, we have developed an acute experimental model for studying the role of microglia in CNS excitotoxicity induced by neuronal hyperactivity. Our model allows us to simultaneously examine the effects of repetitive supramaximal stimulation on axonal morphology, neuronal membrane potential, and microglial migration, using cortical brain slices from Iba-1 eGFP mice. We demonstrate that microglia exert an acute and highly localized neuroprotective action under conditions of neuronal hyperactivity. Evoking repetitive action potentials in individual layer 2/3 pyramidal neurons elicited swelling of axons, but not dendrites, which was accompanied by a large, sustained depolarization of soma membrane potential. Microglial processes migrated to these swollen axons in a mechanism involving both ATP and glutamate release via volume-activated anion channels. This migration was followed by intensive microglial wrapping of affected axons and, in some cases, the removal of axonal debris that induced a rapid soma membrane repolarization back to resting potentials. When the microglial migration was pharmacologically blocked, the activity-induced depolarization continued until cell death ensued, demonstrating that the microglia–axon contact served to prevent pathological depolarization of the soma and maintain neuronal viability. This is a novel aspect of microglia surveillance: detecting, wrapping, and rescuing neuronal soma from damage due to excessive activity. PMID:27390772

  15. [Forensic medical assessment of vascular and neuronal lesions in the brain associated with acute blood loss and anemia].

    PubMed

    Indiaminov, S I

    2010-01-01

    Brain tissues available for examination in the present study were obtained from 30 subjects who died from the blood loss following injuries to blood vessels and internal organs inflicted by sharp objects. The study revealed variable character of tanatogenesis induced by acute blood loss and anemia. Tanatogenesis associated with injuries to the heart and major blood vessels is most likely due to the deficiency of blood in the microcirculatory system developing in the terminal period. The main tanatogenic factors in subjects with multiple injuries to peripheral vessels are vascular dystonia and abnormal rheological properties of blood. PMID:20394188

  16. Acute Lonomia obliqua caterpillar envenomation-induced physiopathological alterations in rats: evidence of new toxic venom activities and the efficacy of serum therapy to counteract systemic tissue damage.

    PubMed

    Berger, Markus; Beys-da-Silva, Walter Orlando; Santi, Lucélia; de Oliveira, Iuri Marques; Jorge, Patrícia Mendes; Henriques, João Antônio Pêgas; Driemeier, David; Vieira, Maria Aparecida Ribeiro; Guimarães, Jorge Almeida

    2013-11-01

    The clinical manifestations of Lonomia obliqua caterpillar envenomation are systemic hemorrhage and acute kidney injury. In an effort to better understand the physiopathological mechanisms of envenomation, a rat model was established to study systemic tissue damage during L. obliqua envenomation. An array of acute venom effects was characterized, including biochemical, hematological, histopathological, myotoxic and genotoxic alterations. Rapid increases in serum alanine and aspartate transaminases, γ-glutamyl transferase, lactate dehydrogenase, hemoglobin, bilirubin, creatinine, urea and uric acid were observed, indicating that intravascular hemolysis and liver and kidney damage had occurred. Treatment with a specific antivenom (antilonomic serum) for up to 2 h post-venom injection neutralized the biochemical alterations. However, treatment after 6 h post-venom injection failed to normalize all biochemical parameters, despite its efficacy in reversing coagulation dysfunction. The hematological findings were consistent with hemolytic anemia and neutrophilic leukocytosis. The histopathological alterations were mainly related to hemorrhage and inflammation in the subcutaneous tissue, lung, heart and kidneys. Signs of congestion and hemosiderosis were evident in the spleen, and hemoglobin and/or myoglobin casts were also detected in the renal tubules. Increased levels of creatine kinase and creatine kinase-MB were correlated with the myocardial necrosis observed in vivo and confirmed the myotoxicity detected in vitro in isolated extensor digitorum longus muscles. Significant DNA damage was observed in the kidneys, heart, lung, liver and lymphocytes. The majority of the DNA lesions in the kidney were due to oxidative damage. The results presented here will aid in understanding the pathology underlying Lonomia's envenomation. PMID:23994591

  17. Intrathecal Injection of 3-Methyladenine Reduces Neuronal Damage and Promotes Functional Recovery via Autophagy Attenuation after Spinal Cord Ischemia/Reperfusion Injury in Rats.

    PubMed

    Wei, Xing; Zhou, Zhentao; Li, Lingyun; Gu, Jun; Wang, Chen; Xu, Fuqi; Dong, Qirong; Zhou, Xiaozhong

    2016-01-01

    The present study aimed to determine the occurrence of autophagy following ischemia/reperfusion (I/R) injury in the rat spinal cord and whether autophagy inhibition contributes to neural tissue damage and locomotor impairment. A spinal cord I/R model was induced via descending thoracic aorta occlusion for 10 min using systemic hypotension (40 mmHg) in adult male Sprague-Dawley rats. Then, 600 nmol 3-methyladenine (3-MA) or vehicle was intrathecally administered. Ultrastructural spinal cord changes were observed via transmission electron microscopy (TEM) and immunofluorescent double-labeling. Western blots were used to determine the protein expression of microtubule-associated protein light chain 3 (LC3) and Beclin 1. Autophagy was activated after spinal cord I/R injury as demonstrated by significantly increased LC3 and Beclin 1 expression at 3-48 h after injury. Furthermore, TEM images indicated the presence of autophagosomes and autolysosomes in the injured spinal cord. 3-MA significantly decreased LC3 and Beclin 1 expression and the number of LC3-positive cells in spinal cord of I/R versus vehicle groups. Moreover, the 3-MA-treated rats exhibited better neurobehavioral scores compared with control rats. These findings suggest activation of autophagy leading to neuronal cell death in the I/R injured spinal cord. These effects were significantly inhibited by intrathecal 3-MA administration. Thus intrathecal 3-MA administration may represent a novel treatment target following spinal cord I/R injury. PMID:27150140

  18. Acute administration of a small molecule p75NTR ligand does not prevent hippocampal neuron loss nor development of spontaneous seizures after pilocarpine-induced status epilepticus

    PubMed Central

    Grabenstatter, H.L.; Carlsen, J.; Raol, Y.H.; Yang, T.; Hund, D.; Del Angel, Y. Cruz; White, A.M.; Gonzalez, M.I.; Longo, F.M.; Russek, S.J.; Brooks-Kayal, A.R.

    2014-01-01

    Neurotrophins, such as brain-derived neurotrophic factor (BDNF), are initially expressed in a precursor form (e.g., proBDNF) and cleaved to form mature BDNF (mBDNF). Following pilocarpine-induced status epilepticus (SE), increases in neurotrophins regulate a wide variety of cell signaling pathways including pro-survival and cell-death machinery in a receptor-specific manner. ProBDNF preferentially binds to the p75 neurotrophin receptor (p75NTR), while mBDNF is the major ligand of the tropomyosin related kinase receptor (TrkB). To elucidate a potential role of p75NTR in acute stages of epileptogenesis, rats were injected prior to and at onset of SE with LM11A-31, a small molecule ligand that binds to p75NTR to promote survival signaling and inhibit neuronal cell death. Modulation of early p75NTR signaling and its effects on (1) electrographic SE, (2) SE-induced neurodegeneration, and (3) subsequent spontaneous seizures were examined following LM11A-31 administration. Despite an established neuroprotective effect of LM11A-31 in several animal models of neurodegenerative disorders (e.g., Alzheimer’s disease, traumatic brain injury, and spinal cord injury), high-dose LM11A-31 administration prior to and at onset of SE did not reduce the intensity of electrographic SE, prevent SE-induced neuronal cell injury, nor inhibit the progression of epileptogenesis. Further studies are required to understand the role of p75NTR activation during epileptogenesis and in seizure-induced cell injury in the hippocampus among other potential cellular pathologies contributing to the onset of spontaneous seizures. Additional studies utilizing more prolonged treatment with LM11A-31 are required to reach a definite conclusion on its potential neuroprotective role in epilepsy. PMID:24801281

  19. Acute Cocaine Induces Fast Activation of D1 Receptor and Progressive Deactivation of D2 Receptor Strial Neurons: In Vivo Optical Microprobe [Ca(superscript)2+]subscript)i Imaging

    SciTech Connect

    Du, C.; Luo, Z.; Volkow, N.D.; Heintz, N.; Pan, Y.; Du, C.

    2011-09-14

    Cocaine induces fast dopamine increases in brain striatal regions, which are recognized to underlie its rewarding effects. Both dopamine D1 and D2 receptors are involved in cocaine's reward but the dynamic downstream consequences of cocaine effects in striatum are not fully understood. Here we used transgenic mice expressing EGFP under the control of either the D1 receptor (D1R) or the D2 receptor (D2R) gene and microprobe optical imaging to assess the dynamic changes in intracellular calcium ([Ca{sup 2+}]{sub i} ) responses (used as marker of neuronal activation) to acute cocaine in vivo separately for D1R- versus D2R-expressing neurons in striatum. Acute cocaine (8 mg/kg, i.p.) rapidly increased [Ca{sup 2+}]{sub i} in D1R-expressing neurons (10.6 {+-} 3.2%) in striatum within 8.3 {+-} 2.3 min after cocaine administration after which the increases plateaued; these fast [Ca{sup 2+}]{sub i} increases were blocked by pretreatment with a D1R antagonist (SCH23390). In contrast, cocaine induced progressive decreases in [Ca{sup 2+}]{sub i} in D2R-expressing neurons (10.4 {+-} 5.8%) continuously throughout the 30 min that followed cocaine administration; these slower [Ca{sup 2+}]{sub i} decreases were blocked by pretreatment with a D2R antagonist (raclopride). Since activation of striatal D1R-expressing neurons (direct-pathway) enhances cocaine reward, whereas activation of D2R expressing neurons suppresses it (indirect-pathway) (Lobo et al., 2010), this suggests that cocaine's rewarding effects entail both its fast stimulation ofD1R (resulting in abrupt activation of direct-pathway neurons) and a slower stimulation of D2R (resulting in longer-lasting deactivation of indirect-pathway neurons). We also provide direct in vivo evidence of D2R and D1R interactions in the striatal responses to acute cocaine administration.

  20. Anti-B7-H3 monoclonal antibody ameliorates the damage of acute experimental pancreatitis by attenuating the inflammatory response.

    PubMed

    Zhuang, Xiaohui; Shen, Jiaqing; Jia, Zhengyu; Wu, Airong; Xu, Ting; Shi, Yuqi; Xu, Chunfang

    2016-06-01

    B7-H3, a recently discovered B7 family member, is documented as a regulator in the inflammatory response as well as T cell-mediated immune responses. In this paper, we find that patients with acute pancreatitis revealed overwhelming levels of serum soluble B7-H3 (sB7-H3) associated with the clinical outcomes. Furthermore, B7-H3 protein was marked increased in l-arginine-induced acute experimental pancreatitis. Anti-B7-H3 monoclonal antibody treatment attenuated the proinflammatory cytokine production, downregulated the activation of the NF-κB signaling pathway, and ameliorated the pancreas disruption in l-arginine-induced pancreatitis. In addition, although l-arginine alone failed to induce the production of proinflammatory cytokine and anti-B7-H3 mAb had no effect on the proinflammatory cytokine production of acinar cells, administration of anti-B7-H3 mAb in the coculture model of acinar cells and macrophages stimulated by l-arginine displayed the similar effects. On the whole, B7-H3 participates in the development of acute pancreatitis, and anti-B7-H3 monoclonal antibody ameliorates severity of acute experimental pancreatitis via attenuation of the inflammatory response. PMID:27003113

  1. The Effect of Acute Microgravity on Mechanically-Induced Membrane Damage and Membrane-Membrane Fusion Events

    NASA Technical Reports Server (NTRS)

    Clarke, Mark, S. F.; Vanderburg, Charles R.; Feedback, Daniel L.

    2001-01-01

    Although it is unclear how a living cell senses gravitational forces there is no doubt that perturbation of the gravitational environment results in profound alterations in cellular function. In the present study, we have focused our attention on how acute microgravity exposure during parabolic flight affects the skeletal muscle cell plasma membrane (i.e. sarcolemma), with specific reference to a mechanically-reactive signaling mechanism known as mechanically-induced membrane disruption or "wounding". This response is characterized by both membrane rupture and membrane resealing events mediated by membrane-membrane fusion. We here present experimental evidence that acute microgravity exposure can inhibit membrane-membrane fusion events essential for the resealing of sarcolemmal wounds in individual human myoblasts. Additional evidence to support this contention comes from experimental studies that demonstrate acute microgravity exposure also inhibits secretagogue-stimulated intracellular vesicle fusion with the plasma membrane in HL-60 cells. Based on our own observations and those of other investigators in a variety of ground-based models of membrane wounding and membrane-membrane fusion, we suggest that the disruption in the membrane resealing process observed during acute microgravity is consistent with a microgravity-induced decrease in membrane order.

  2. The effect of acute microgravity on mechanically-induced membrane damage and membrane-membrane fusion events

    NASA Technical Reports Server (NTRS)

    Clarke, M. S.; Vanderburg, C. R.; Feeback, D. L.; McIntire, L. V. (Principal Investigator)

    2001-01-01

    Although it is unclear how a living cell senses gravitational forces there is no doubt that perturbation of the gravitational environment results in profound alterations in cellular function. In the present study, we have focused our attention on how acute microgravity exposure during parabolic flight affects the skeletal muscle cell plasma membrane (i.e. sarcolemma), with specific reference to a mechanically-reactive signaling mechanism known as mechanically-induced membrane disruption or "wounding". Both membrane rupture and membrane resealing events mediated by membrane-membrane fusion characterize this response. We here present experimental evidence that acute microgravity exposure can inhibit membrane-membrane fusion events essential for the resealing of sarcolemmal wounds in individual human myoblasts. Additional evidence to support this contention comes from experimental studies that demonstrate acute microgravity exposure also inhibits secretagogue-stimulated intracellular vesicle fusion with the plasma membrane in HL-60 cells. Based on our own observations and those of other investigators in a variety of ground-based models of membrane wounding and membrane-membrane fusion, we suggest that the disruption in the membrane resealing process observed during acute microgravity is consistent with a microgravity-induced decrease in membrane order.

  3. Discrete cell gene profiling of ventral tegmental dopamine neurons after acute and chronic cocaine self-administration.

    PubMed

    Backes, Eric; Hemby, Scott E

    2003-11-01

    Chronic cocaine administration induces a number of biochemical alterations within the mesolimbic dopamine system that may mediate various aspects of the addictive process such as sensitization, craving, withdrawal, and relapse. In the present study, rats were allowed to self-administer cocaine (0.5 mg/infusion) for 1 or 20 days. Tyrosine hydroxylase immunopositive cells were microdissected from the ventral tegmental area (VTA) using laser capture microdissection, and changes in the abundances of 95 mRNAs were assessed using cDNA macroarrays. Five GABA-A receptor subunit mRNAs (alpha4, alpha6, beta2, gamma2, and delta) were down-regulated at both 1 and 20 days of cocaine self-administration. In contrast, the catalytic subunit of protein phosphatase 2A (PP2alpha), GABA-A alpha1, and Galphai2 were significantly increased at both time points. Additionally, calcium/calmodulin-dependent protein kinase IIalpha mRNA levels were increased initially followed by a slight decrease after 20 days, whereas neuronal nitric-oxide synthase mRNA levels were initially decreased but returned to near control levels by day 20. These results indicate that alterations of specific GABA-A receptor subtypes and other signal transduction transcripts seem to be specific neuroadaptations associated with cocaine self-administration. Moreover, as subunit composition determines the functional properties of GABA-A receptors, the observed changes may indicate alterations in the excitability of dopamine transmission underlying long-term biochemical and behavioral effects of cocaine. PMID:12966149

  4. Sleep deprivation does not affect neuronal susceptibility to mild traumatic brain injury in the rat

    PubMed Central

    Caron, Aimee M; Stephenson, Richard

    2015-01-01

    Mild and moderate traumatic brain injuries (TBIs) (and concussion) occur frequently as a result of falls, automobile accidents, and sporting activities, and are a major cause of acute and chronic disability. Fatigue and excessive sleepiness are associated with increased risk of accidents, but it is unknown whether prior sleep debt also affects the pathophysiological outcome of concussive injury. Using the “dark neuron” (DN) as a marker of reversible neuronal damage, we tested the hypothesis that acute (48 hours) total sleep deprivation (TSD) and chronic sleep restriction (CSR; 10 days, 6-hour sleep/day) affect DN formation following mild TBI in the rat. TSD and CSR were administered using a walking wheel apparatus. Mild TBI was administered under anesthesia using a weight-drop impact model, and the acute neuronal response was observed without recovery. DNs were detected using standard bright-field microscopy with toluidine blue stain following appropriate tissue fixation. DN density was low under home cage and sleep deprivation control conditions (respective median DN densities, 0.14% and 0.22% of neurons), and this was unaffected by TSD alone (0.1%). Mild TBI caused significantly higher DN densities (0.76%), and this was unchanged by preexisting acute or chronic sleep debt (TSD, 0.23%; CSR, 0.7%). Thus, although sleep debt may be predicted to increase the incidence of concussive injury, the present data suggest that sleep debt does not exacerbate the resulting neuronal damage. PMID:26124685

  5. North American ginseng protects against muscle damage and reduces neutrophil infiltration after an acute bout of downhill running in rats.

    PubMed

    Estaki, Mehrbod; Noble, Earl G

    2015-02-01

    Eccentric muscle contractions such as those experienced during downhill running are associated with inflammation, delayed-onset of muscle soreness, myofiber damage, and various functional deficits. North American ginseng (Panax quinquefolius L.) has been reported to possess anti-inflammatory properties and thus may offset some of this exercise-induced damage. Hence, we tested the hypothesis that intervention with North American ginseng would reduce eccentric exercise-induced muscle damage and inflammation. Male Wistar rats were fed (300 mg/(kg·day)(-1)) of either an alcohol (AL) or aqueous (AQ) extract of North American ginseng for 14 days before a single bout of downhill running and were compared with matching nonexercised (C) groups. Plasma creatine kinase levels were significantly reduced in both ginseng treated groups compared with the C group that received a water placebo (p < 0.002). Further, the AQ but not AL group also showed attenuated morphological signs of damage (hemotoxylin and eosin) as well as reduced levels of infiltrating neutrophils (HIS48) in the soleus muscle (p < 0.001). In summary, supplementation with an AQ but not AL extract of North American ginseng was able to reduce eccentric exercise-induced muscle damage and inflammation. PMID:25531801

  6. The Different Effects of BMI and WC on Organ Damage in Patients from a Cardiac Rehabilitation Program after Acute Coronary Syndrome

    PubMed Central

    Xu, Lin; Zhao, Hui; Qiu, Jian; Zhu, Wei; Lei, Hongqiang; Cai, Zekun; Lin, Wan-Hua; Huang, Wenhua; Zhang, Heye; Zhang, Yuan-Ting

    2015-01-01

    One of the purposes of cardiac rehabilitation (CR) after acute coronary syndrome (ACS) is to monitor and control weight of the patient. Our study is to compare the different obesity indexes, body mass index (BMI), and waist circumference (WC), through one well-designed CR program (CRP) with ACS in Guangzhou city of Guangdong Province, China, in order to identify different effects of BMI and WC on organ damage. In our work, sixty-one patients between October 2013 and January 2014 fulfilled our study. We collected the vital signs by medical records, the clinical variables of body-metabolic status by fasting blood test, and the organ damage variables by submaximal exercise treadmill test (ETT) and ultrasonic cardiogram (UCG) both on our inpatient and four-to-five weeks of outpatient part of CRP after ACS. We mainly used two-tailed Pearson's test and liner regression to evaluate the relationship of BMI/WC and organ damage. Our results confirmed that WC could be more accurate than BMI to evaluate the cardiac function through the changes of left ventricular structure on the CRP after ACS cases. It makes sense of early diagnosis, valid evaluation, and proper adjustment to ACS in CRP of the obesity individuals in the future. PMID:26247035

  7. Ferulic Acid Regulates the Nrf2/Heme Oxygenase-1 System and Counteracts Trimethyltin-Induced Neuronal Damage in the Human Neuroblastoma Cell Line SH-SY5Y

    PubMed Central

    Catino, Stefania; Paciello, Fabiola; Miceli, Fiorella; Rolesi, Rolando; Troiani, Diana; Calabrese, Vittorio; Santangelo, Rosaria; Mancuso, Cesare

    2016-01-01

    Over the past years, several lines of evidence have pointed out the efficacy of ferulic acid (FA) in counteracting oxidative stress elicited by β-amyloid or free radical initiators, based on the ability of this natural antioxidant to up-regulate the heme oxygenase-1 (HO-1) and biliverdin reductase (BVR) system. However, scarce results can be found in literature regarding the cytoprotective effects of FA in case of damage caused by neurotoxicants. The aim of this work is to investigate the mechanisms through which FA exerts neuroprotection in SH-SY5Y neuroblastoma cells exposed to the neurotoxin trimethyltin (TMT). FA (1–10 μM for 6 h) dose-dependently increased both basal and TMT (10 μM for 24 h)-induced HO-1 expression in SH-SY5Y cells by fostering the nuclear translocation of the transcriptional activator Nrf2. In particular, the co-treatment of FA (10 μM) with TMT was also responsible for the nuclear translocation of HO-1 in an attempt to further increase cell stress response in SH-SY5Y cells. In addition to HO-1, FA (1–10 μM for 6 h) dose-dependently increased the basal expression of BVR. The antioxidant and neuroprotective features of FA, through the increase of HO activity, were supported by the evidence that FA inhibited TMT (10 μM)-induced lipid peroxidation (evaluated by detecting 4-hydroxy-nonenal) and DNA fragmentation in SH-SY5Y cells and that this antioxidant effect was reversed by the HO inhibitor Zinc-protoporphyrin-IX (5 μM). Among the by-products of the HO/BVR system, carbon monoxide (CORM-2, 50 nM) and bilirubin (BR, 50 nM) significantly inhibited TMT-induced superoxide anion formation in SH-SY5Y cells. All together, these results corroborate the neuroprotective effect of FA through the up-regulation of the HO-1/BVR system, via carbon monoxide and BR formation, and provide the first evidence on the role of HO-1/Nrf2 axis in FA-related enhancement of cell stress response in human neurons. PMID:26779023

  8. Segregation and crosstalk of D1 receptor-mediated activation of ERK in striatal medium spiny neurons upon acute administration of psychostimulants.

    PubMed

    Gutierrez-Arenas, Omar; Eriksson, Olivia; Kotaleski, Jeanette Hellgren

    2014-01-01

    The convergence of corticostriatal glutamate and dopamine from the midbrain in the striatal medium spiny neurons (MSN) triggers synaptic plasticity that underlies reinforcement learning and pathological conditions such as psychostimulant addiction. The increase in striatal dopamine produced by the acute administration of psychostimulants has been found to activate not only effectors of the AC5/cAMP/PKA signaling cascade such as GluR1, but also effectors of the NMDAR/Ca(2+)/RAS cascade such as ERK. The dopamine-triggered effects on both these cascades are mediated by D1R coupled to Golf but while the phosphorylation of GluR1 is affected by reductions in the available amount of Golf but not of D1R, the activation of ERK follows the opposite pattern. This segregation is puzzling considering that D1R-induced Golf activation monotonically increases with DA and that there is crosstalk from the AC5/cAMP/PKA cascade to the NMDAR/Ca(2+)/RAS cascade via a STEP (a tyrosine phosphatase). In this work, we developed a signaling model which accounts for this segregation based on the assumption that a common pool of D1R and Golf is distributed in two D1R/Golf signaling compartments. This model integrates a relatively large amount of experimental data for neurons in vivo and in vitro. We used it to explore the crosstalk topologies under which the sensitivities of the AC5/cAMP/PKA signaling cascade to reductions in D1R or Golf are transferred or not to the activation of ERK. We found that the sequestration of STEP by its substrate ERK together with the insensitivity of STEP activity on targets upstream of ERK (i.e. Fyn and NR2B) to PKA phosphorylation are able to explain the experimentally observed segregation. This model provides a quantitative framework for simulation based experiments to study signaling required for long term potentiation in MSNs. PMID:24499932

  9. Neurovascular changes in acute, sub-acute and chronic mouse models of Parkinson's disease.

    PubMed

    Sarkar, Sumit; Raymick, James; Mann, Dushyant; Bowyer, John F; Hanig, Joseph P; Schmued, Larry C; Paule, Merle G; Chigurupati, Srinivasulu

    2014-02-01

    Although selective neurodegeneration of nigro-striatal dopaminergic neurons is widely accepted as a cause of Parkinson's disease (PD), the role of vascular components in the brain in PD pathology is not well understood. However, the neurodegeneration seen in PD is known to be associated with neuroinflammatory-like changes that can affect or be associated with brain vascular function. Thus, dysfunction of the capillary endothelial cell component of neurovascular units present in the brain may contribute to the damage to dopaminergic neurons that occurs in PD. An animal model of PD employing acute, sub-acute and chronic exposures of mice to methyl-phenyl-tetrahydropyridine (MPTP) was used to determine the extent to which brain vasculature may be damaged in PD. Fluoro-Turquoise gelatin labeling of microvessels and endothelial cells was used to determine the extent of vascular damage produced by MPTP. In addition, tyrosine hydroxylase (TH) and NeuN were employed to detect and quantify dopaminergic neuron damage in the striatum (CPu) and substantia nigra (SNc). Gliosis was evaluated through GFAP immunohistochemistry. MPTP treatment drastically reduced TH immunoreactive neurons in the SNc (20.68 ± 2.83 in acute; 22.98 ± 2.14 in sub-acute; 10.20 ± 2.24 in chronic vs 34.88 ± 2.91 in controls; p<0.001). Similarly, TH immunoreactive terminals were dramatically reduced in the CPu of MPTP treated mice. Additionally, all three MPTP exposures resulted in a decrease in the intensity, length, and number of vessels in both CPu and SNc. Degenerative vascular changes such as endothelial cell 'clusters' were also observed after MPTP suggesting that vasculature damage may be modifying the availability of nutrients and exposing blood cells and/or toxic substances to neurons and glia. In summary, vascular damage and degeneration could be an additional exacerbating factor in the progression of PD, and therapeutics that protect and insure vascular integrity may be novel treatments for

  10. Clinically relevant concentration of pregabalin has no acute inhibitory effect on excitation of dorsal horn neurons under normal or neuropathic pain conditions: An intracellular calcium-imaging study in spinal cord slices from adult rats.

    PubMed

    Baba, Hiroshi; Petrenko, Andrey B; Fujiwara, Naoshi

    2016-10-01

    Pregabalin is thought to exert its therapeutic effect in neuropathic pain via binding to α2δ-1 subunits of voltage-gated calcium (Ca(2+)) channels. However, the exact analgesic mechanism after its binding to α2δ-1 subunits remains largely unknown. Whether a clinical concentration of pregabalin (≈10μM) can cause acute inhibition of dorsal horn neurons in the spinal cord is controversial. To address this issue, we undertook intracellular Ca(2+)-imaging studies using spinal cord slices with an intact attached L5 dorsal root, and examined if pregabalin acutely inhibits the primary afferent stimulation-evoked excitation of dorsal horn neurons in normal rats and in rats with streptozotocin-induced painful diabetic neuropathy. Under normal conditions, stimulation of a dorsal root evoked Ca(2+) signals predominantly in the superficial dorsal horn. Clinically relevant (10μM) and a very high concentration of pregabalin (100μM) did not affect the intensity or spread of dorsal root stimulation-evoked Ca(2+) signals, whereas an extremely high dose of pregabalin (300μM) slightly but significantly attenuated Ca(2+) signals in normal rats and in diabetic neuropathic (DN) rats. There was no difference between normal rats and DN rats with regard to the extent of signal attenuation at all concentrations tested. These results suggest that the activity of dorsal horn neurons in the spinal cord is not inhibited acutely by clinical doses of pregabalin under normal or DN conditions. It is very unlikely that an acute inhibitory action in the dorsal horn is the main analgesic mechanism of pregabalin in neuropathic pain states. PMID:27543338

  11. Huperzine A ameliorates damage induced by acute myocardial infarction in rats through antioxidant, anti-apoptotic and anti-inflammatory mechanisms.

    PubMed

    Sui, Xizhong; Gao, Changqing

    2014-01-01

    Huperzine A (HupA), an alkaloid used in traditional Chinese medicine and isolated from Huperzia serrata, has been shown to possess diverse biological activities. The present study was undertaken to evaluate the cardioprotective potential of HupA in myocardial ischemic damage using a rat model of acute myocardial infarction. HupA significantly diminished the infarct size and inhibited the activities of myocardial enzymes, including creatine kinase (CK), the MB isoenzyme of creatine kinase (CK-MB), lactate dehydrogenase (LDH) and cardiac troponin T (cTnT). A significantly reduced activity of malondialdehyde (MDA) and elevated activities of superoxide dismutase (SOD), of the non-enzymatic scavenger enzyme, glutathione (GSH), as well as of glutathione peroxidase (GSH-PX) were found in the HupA-treated groups. Furthermore, decreased protein levels of caspase-3 and Bax, and increased levels of Bcl-2 were observed in the infarcted hearts of the rats treated with various concentrations of HupA. In addition, treatment with HupA markedly inhibited the expression of the nuclear factor-κB (NF-κB) subunit p65, tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). These findings suggest that the cardioprotective potential of HupA is associated with its antioxidant, anti-apoptotic and anti-inflammatory properties in acute myocardial infarction in rats. PMID:24190328

  12. The Role of Inspiratory Muscle Training in Sickle Cell Anemia Related Pulmonary Damage due to Recurrent Acute Chest Syndrome Attacks

    PubMed Central

    Camcıoğlu, Burcu; Boşnak-Güçlü, Meral; Karadallı, Müşerrefe Nur; Akı, Şahika Zeynep; Türköz-Sucak, Gülsan

    2015-01-01

    Background. The sickling of red blood cells causes a constellation of musculoskeletal, cardiovascular, and pulmonary manifestations. A 32-year-old gentleman with sickle cell anemia (SCA) had been suffering from recurrent acute chest syndrome (ACS). Aim. To examine the effects of inspiratory muscle training (IMT) on pulmonary functions, respiratory and peripheral muscle strength, functional exercise capacity, and quality of life in this patient with SCA. Methods. Functional exercise capacity was evaluated using six-minute walk test, respiratory muscle strength using mouth pressure device, hand grip strength using hand-held dynamometer, pain using Visual Analogue Scale, fatigue using Fatigue Severity Scale, dyspnea using Modified Medical Research Council Scale, and health related quality of life using European Organization for Research and Treatment of Cancer QOL measurement. Results. A significant improvement has been demonstrated in respiratory muscle strength, functional exercise capacity, pain, fatigue, dyspnea, and quality of life. There was no admission to emergency department due to acute chest syndrome in the following 12 months after commencing regular erythrocytapheresis. Conclusion. This is the first report demonstrating the beneficial effects of inspiratory muscle training on functional exercise capacity, respiratory muscle strength, pain, fatigue, dyspnea, and quality of life in a patient with recurrent ACS. PMID:26060589

  13. The Role of Inspiratory Muscle Training in Sickle Cell Anemia Related Pulmonary Damage due to Recurrent Acute Chest Syndrome Attacks.

    PubMed

    Camcıoğlu, Burcu; Boşnak-Güçlü, Meral; Karadallı, Müşerrefe Nur; Akı, Şahika Zeynep; Türköz-Sucak, Gülsan

    2015-01-01

    Background. The sickling of red blood cells causes a constellation of musculoskeletal, cardiovascular, and pulmonary manifestations. A 32-year-old gentleman with sickle cell anemia (SCA) had been suffering from recurrent acute chest syndrome (ACS). Aim. To examine the effects of inspiratory muscle training (IMT) on pulmonary functions, respiratory and peripheral muscle strength, functional exercise capacity, and quality of life in this patient with SCA. Methods. Functional exercise capacity was evaluated using six-minute walk test, respiratory muscle strength using mouth pressure device, hand grip strength using hand-held dynamometer, pain using Visual Analogue Scale, fatigue using Fatigue Severity Scale, dyspnea using Modified Medical Research Council Scale, and health related quality of life using European Organization for Research and Treatment of Cancer QOL measurement. Results. A significant improvement has been demonstrated in respiratory muscle strength, functional exercise capacity, pain, fatigue, dyspnea, and quality of life. There was no admission to emergency department due to acute chest syndrome in the following 12 months after commencing regular erythrocytapheresis. Conclusion. This is the first report demonstrating the beneficial effects of inspiratory muscle training on functional exercise capacity, respiratory muscle strength, pain, fatigue, dyspnea, and quality of life in a patient with recurrent ACS. PMID:26060589

  14. Neurons are MHC Class I-Dependent Targets for CD8 T Cells upon Neurotropic Viral Infection

    PubMed Central

    Chevalier, Grégoire; Suberbielle, Elsa; Monnet, Céline; Duplan, Valérie; Martin-Blondel, Guillaume; Farrugia, Fanny; Le Masson, Gwendal; Liblau, Roland; Gonzalez-Dunia, Daniel

    2011-01-01

    Following infection of the central nervous system (CNS), the immune system is faced with the challenge of eliminating the pathogen without causing significant damage to neurons, which have limited capacities of renewal. In particular, it was thought that neurons were protected from direct attack by cytotoxic T lymphocytes (CTL) because they do not express major histocompatibility class I (MHC I) molecules, at least at steady state. To date, most of our current knowledge on the specifics of neuron-CTL interaction is based on studies artificially inducing MHC I expression on neurons, loading them with exogenous peptide and applying CTL clones or lines often differentiated in culture. Thus, much remains to be uncovered regarding the modalities of the interaction between infected neurons and antiviral CD8 T cells in the course of a natural disease. Here, we used the model of neuroinflammation caused by neurotropic Borna disease virus (BDV), in which virus-specific CTL have been demonstrated as the main immune effectors triggering disease. We tested the pathogenic properties of brain-isolated CD8 T cells against pure neuronal cultures infected with BDV. We observed that BDV infection of cortical neurons triggered a significant up regulation of MHC I molecules, rendering them susceptible to recognition by antiviral CTL, freshly isolated from the brains of acutely infected rats. Using real-time imaging, we analyzed the spatio-temporal relationships between neurons and CTL. Brain-isolated CTL exhibited a reduced mobility and established stable contacts with BDV-infected neurons, in an antigen- and MHC-dependent manner. This interaction induced rapid morphological changes of the neurons, without immediate killing or impairment of electrical activity. Early signs of neuronal apoptosis were detected only hours after this initial contact. Thus, our results show that infected neurons can be recognized efficiently by brain-isolated antiviral CD8 T cells and uncover the unusual

  15. Antiretrovirals, Methamphetamine, and HIV-1 Envelope Protein gp120 Compromise Neuronal Energy Homeostasis in Association with Various Degrees of Synaptic and Neuritic Damage

    PubMed Central

    Sanchez, Ana B.; Varano, Giuseppe P.; de Rozieres, Cyrus M.; Maung, Ricky; Catalan, Irene C.; Dowling, Cari C.; Sejbuk, Natalia E.; Hoefer, Melanie M.

    2015-01-01

    HIV-1 infection frequently causes HIV-associated neurocognitive disorders (HAND) despite combination antiretroviral therapy (cART). Evidence is accumulating that components of cART can themselves be neurotoxic upon long-term exposure. In addition, abuse of psychostimulants, such as methamphetamine, seems to aggravate HAND and compromise antiretroviral therapy. However, the combined effect of virus and recreational and therapeutic drugs on the brain is poorly understood. Therefore, we exposed mixed neuronal-glial cerebrocortical cells to antiretrovirals (ARVs) (zidovudine [AZT], nevirapine [NVP], saquinavir [SQV], and 118-D-24) of four different pharmacological categories and to methamphetamine and, in some experiments, the HIV-1 gp120 protein for 24 h and 7 days. Subsequently, we assessed neuronal injury by fluorescence microscopy, using specific markers for neuronal dendrites and presynaptic terminals. We also analyzed the disturbance of neuronal ATP levels and assessed the involvement of autophagy by using immunofluorescence and Western blotting. ARVs caused alterations of neurites and presynaptic terminals primarily during the 7-day incubation and depending on the specific compounds and their combinations with and without methamphetamine. Similarly, the loss of neuronal ATP was context specific for each of the drugs or combinations thereof, with and without methamphetamine or viral gp120. Loss of ATP was associated with activation of AMP-activated protein kinase (AMPK) and autophagy, which, however, failed to restore normal levels of neuronal ATP. In contrast, boosting autophagy with rapamycin prevented the long-term drop of ATP during exposure to cART in combination with methamphetamine or gp120. Our findings indicate that the overall positive effect of cART on HIV infection is accompanied by detectable neurotoxicity, which in turn may be aggravated by methamphetamine. PMID:26482305

  16. Assessment of Newly Synthesized Mitochondrial DNA Using BrdU Labeling in Primary Neurons from Alzheimer’s Disease Mice: Implications for Impaired Mitochondrial Biogenesis and Synaptic Damage

    PubMed Central

    Calkins, Marcus J.; Reddy, P. Hemachandra

    2011-01-01

    The purpose our study was to assess mitochondrial biogenesis and distribution in murine primary neurons. Using 5-bromo-2-deoxyuridie (BrdU) incorporation and primary neurons, we studied the mitochondrial biogenesis and mitochondrial distribution in hippocampal neurons from amyloid beta precursor protein (AβPP) transgenic mice and wild-type (WT) neurons treated with oxidative stressors, rotenone and H2O2. We found that after 20 hr of labeling, BrdU incorporation was specific to porin-positive mitochondria. The proportion of mitochondrial area that labeled with BrdU was 40.3 ± 6.3% at 20 hr. The number of mitochondria with newly synthesized DNA was higher in AβPP neuronal cell bodies than in the cell bodies of WT neurons (AβPP, 45.23 ± 2.67 BrdU-positive/cell body; WT, 32.92 ± 2.49 BrdU-positive/cell body; p = 0.005). In neurites, the number of BrdU-positive mitochondria decreased in AβPP cultures compared to WT neurons (AβPP, 0.105 ± 0.008 BrdU-positive/μm neurite; WT, 0.220 ± 0.036 BrdU-positive−/−μm neurite; p = 0.010). Further, BrdU in the cell body increased when neurons were treated with low doses of H2O2 (49.6 ± 2.7 BrdU-positive/cell body, p = 0.0002 compared to untreated cells), while the neurites showed decreased BrdU staining (0.122 ± 0.010 BrdU-positive/μm neurite, p = 0.005 compared to the untreated). BrdU labeling was increased in the cell body under rotenone treatment. Additionally, under rotenone treatment, the content of BrdU labeling decreased in neurites. These findings suggest that Aβ and mitochondrial toxins enhance mitochondrial fragmentation in cell body, and may cause impaired axonal transport of mitochondria leading to synaptic degeneration. PMID:21549836

  17. Assessment of newly synthesized mitochondrial DNA using BrdU labeling in primary neurons from Alzheimer's disease mice: Implications for impaired mitochondrial biogenesis and synaptic damage.

    PubMed

    Calkins, Marcus J; Reddy, P Hemachandra

    2011-09-01

    The purpose of our study was to assess mitochondrial biogenesis and distribution in murine primary neurons. Using 5-bromo-2-deoxyuridine (BrdU) incorporation and primary neurons, we studied the mitochondrial biogenesis and mitochondrial distribution in hippocampal neurons from amyloid beta precursor protein (AβPP) transgenic mice and wild-type (WT) neurons treated with oxidative stressors, rotenone and H(2)O(2). We found that after 20h of labeling, BrdU incorporation was specific to porin-positive mitochondria. The proportion of mitochondrial area labeled with BrdU was 40.3±6.3% at 20h. The number of mitochondria with newly synthesized DNA was higher in AβPP neuronal cell bodies than in the cell bodies of WT neurons (AβPP, 45.23±2.67 BrdU-positive/cell body; WT, 32.92±2.49 BrdU-positive/cell body; p=0.005). In neurites, the number of BrdU-positive mitochondria decreased in AβPP cultures compared to WT neurons (AβPP, 0.105±0.008 BrdU-positive/μm neurite; WT, 0.220±0.036 BrdU-positive/μm neurite; p=0.010). Further, BrdU in the cell body increased when neurons were treated with low doses of H(2)O(2) (49.6±2.7 BrdU-positive/cell body, p=0.0002 compared to untreated cells), while the neurites showed decreased BrdU staining (0.122±0.010 BrdU-positive/μm neurite, p=0.005 compared to the untreated). BrdU labeling was increased in the cell body under rotenone treatment. Additionally, under rotenone treatment, the content of BrdU labeling decreased in neurites. These findings suggest that Aβ and mitochondrial toxins enhance mitochondrial fragmentation in the cell body, and may cause impaired axonal transport of mitochondria leading to synaptic degeneration. PMID:21549836

  18. Acute kidney failure

    MedlinePlus

    Kidney failure; Renal failure; Renal failure - acute; ARF; Kidney injury - acute ... There are many possible causes of kidney damage. They include: ... cholesterol (cholesterol emboli) Decreased blood flow due to very ...

  19. Innate and drug-induced resistance to acute lung damage caused in rats by alpha-naphthyl thiourea (ANTU) and related compounds.

    PubMed Central

    van den Brenk, H. A.; Kelly, H.; Stone, M. G.

    1976-01-01

    During the 3rd and 4th weeks of life rats were highly resistant to the toxic effects of alpha-naphthyl thiourea (ANTU) and of thiourea and its derivatives but toxicity developed rapidly during the following 2 weeks. Marked resistance to lung damage by toxic thioureas could be induced in older, mature rats by pretreatment with the toxic agent itself (tachyphylaxis), with other toxic and non-toxic antithyroid drugs or with iodine or iodide--even if the rats were pretreated at an early age before susceptibility to the agent developed. ANTU-tachyphylaxis was dose-dependent. Total thyroidectomy did not affect either lung damage induced by ANTU or the resistance due to tachyphylaxis or to pretreatment with iodide or the antithyroid drugs thiourea, 1-ethyl-1-phenyl thiourea or propyl thiouracil. Neither total nor medullary adrenalectomy affected ANTU toxicity. Marked resistance to ANTU-induced lung damage was induced in rats by pretreatment with either an activator (3-4 benzypyrene) or an inhibitor (SKF 525-A) of drug-metabolizine mixed-function microsomal enzyme systems; the inhibitor, sodium phenobarbitone, had no significant effect on toxicity. The sulphydryl compound, AET, induced marked resistance to ANTU; cysteine was less effective. Neither autonomic blockade with nicotine and atropine nor actinomycin D had significant effects on toxicity to ANTU. The acute pulmonary oedema induced in rats by high pressure oxygen, chemical convulsants, pressor agents and ammonium sulphate differed in many respects from that induced by toxic thioureas; it was typically haemorrhagic in nature, did not result in significant pleural effusion, did not exhibit tachyphylaxis, and was not influenced by pretreatment with iodide or derivatives of thiourea. PMID:137734

  20. Pleiotropic effects of spongean alkaloids on mechanisms of cell death, cell cycle progression and DNA damage response (DDR) of acute myeloid leukemia (AML) cells.

    PubMed

    Stuhldreier, Fabian; Kassel, Stefanie; Schumacher, Lena; Wesselborg, Sebastian; Proksch, Peter; Fritz, Gerhard

    2015-05-28

    We investigated cytotoxic mechanisms evoked by the spongean alkaloids aaptamine (Aa) and aeroplysinin-1 (Ap), applied alone and in combination with daunorubicin, employing acute myeloid leukemia (AML) cells. Aa and Ap reduced the viability of AML cells in a dose dependent manner with IC50 of 10-20 µM. Ap triggered apoptotic cell death more efficiently than Aa. Both alkaloids increased the protein level of S139-phosphorylated H2AX (γH2AX), which however was independent of the induction of DNA damage. Expression of the senescence markers p21 and p16 was increased, while the phosphorylation level of p-Chk-2 was reduced following Aa treatment. As a function of dose, Aa and Ap protected or sensitized AML cells against daunorubicin. Protection by Aa was paralleled by reduced formation of ROS and lower level of DNA damage. Both Aa and Ap attenuated daunorubicin-stimulated activation of the DNA damage response (DDR) as reflected on the levels of γH2AX, p-Kap-1 and p-Chk-1. Specifically Ap restored the decrease in S10 phosphorylation of histone H3 resulting from daunorubicin treatment. The cytoprotective effects of Aa and Ap were independent of daunorubicin import/export. Both Aa and Ap abrogated daunorubicin-induced accumulation of cells in S-phase. Inhibition of DNA synthesis was specific for Ap. The data show that Aa and Ap have both congruent and agent-specific pleiotropic effects that are preferential for anticancer drugs. Since Ap showed a broader spectrum of anticancer activities, this compound is suggested as novel lead compound for forthcoming in vivo studies elucidating the usefulness of spongean alkaloids in AML therapy. PMID:25697484

  1. Protective Effect of Edaravone in Primary Cerebellar Granule Neurons against Iodoacetic Acid-Induced Cell Injury

    PubMed Central

    Zhou, Xinhua; Zhu, Longjun; Wang, Liang; Guo, Baojian; Zhang, Gaoxiao; Sun, Yewei; Zhang, Zaijun; Lee, Simon Ming-Yuen; Yu, Pei; Wang, Yuqiang

    2015-01-01

    Edaravone (EDA) is clinically used for treatment of acute ischemic stroke in Japan and China due to its potent free radical-scavenging effect. However, it has yet to be determined whether EDA can attenuate iodoacetic acid- (IAA-) induced neuronal death in vitro. In the present study, we investigated the effect of EDA on damage of IAA-induced primary cerebellar granule neurons (CGNs) and its possible underlying mechanisms. We found that EDA attenuated IAA-induced cell injury in CGNs. Moreover, EDA significantly reduced intracellular reactive oxidative stress production, loss of mitochondrial membrane potential, and caspase 3 activity induced by IAA. Taken together, EDA protected CGNs against IAA-induced neuronal damage, which may be attributed to its antiapoptotic and antioxidative activities. PMID:26557222

  2. Skin pathology induced by snake venom metalloproteinase: acute damage, revascularization, and re-epithelization in a mouse ear model.

    PubMed

    Jiménez, Natalia; Escalante, Teresa; Gutiérrez, José María; Rucavado, Alexandra

    2008-10-01

    Viperid snakebite envenomation induces blistering and dermonecrosis. The pathological alterations induced by a snake venom metalloproteinase in the skin were investigated in a mouse ear model. Metalloproteinase BaP1, from Bothrops asper, induced rapid edema, hemorrhage, and blistering; the latter two effects were abrogated by preincubation with the metalloproteinase inhibitor batimastat. Neutrophils did not play a role in the pathology, as depletion of these cells resulted in a similar histological picture. Blisters are likely to result from the direct proteolytic activity of BaP1 of proteins at the dermal-epidermal junction, probably at the lamina lucida, as revealed by immunostaining for type IV collagen and laminin. Widespread apoptosis of keratinocytes was detected by the TUNEL assay, whereas no apoptosis of capillary endothelial cells was observed. BaP1 induced a drastic reduction in the microvessel density, revealed by immunostaining for the endothelial marker vascular endothelial growth factor receptor-2. This was followed by a rapid angiogenic response, leading to a partial revascularization. Skin damage was followed by inflammation and granulation tissue formation. Then, a successful re-epithelization process occurred, and the skin of the ear regained its normal structure by 2 weeks. Venom metalloproteinase-induced skin damage reproduces the pathological changes described in snakebitten patients. PMID:18449209

  3. Potential Effects of Phytoestrogen Genistein in Modulating Acute Methotrexate Chemotherapy-Induced Osteoclastogenesis and Bone Damage in Rats

    PubMed Central

    King, Tristan J.; Shandala, Tetyana; Lee, Alice M.; Foster, Bruce K.; Chen, Ke-Ming; Howe, Peter R.; Xian, Cory J.

    2015-01-01

    Chemotherapy-induced bone damage is a frequent side effect which causes diminished bone mineral density and fracture in childhood cancer sufferers and survivors. The intensified use of anti-metabolite methotrexate (MTX) and other cytotoxic drugs has led to the need for a mechanistic understanding of chemotherapy-induced bone loss and for the development of protective treatments. Using a young rat MTX-induced bone loss model, we investigated potential bone protective effects of phytoestrogen genistein. Oral gavages of genistein (20 mg/kg) were administered daily, for seven days before, five days during, and three days after five once-daily injections (sc) of MTX (0.75 mg/kg). MTX treatment reduced body weight gain and tibial metaphyseal trabecular bone volume (p < 0.001), increased osteoclast density on the trabecular bone surface (p < 0.05), and increased the bone marrow adipocyte number in lower metaphyseal bone (p < 0.001). Genistein supplementation preserved body weight gain (p < 0.05) and inhibited ex vivo osteoclast formation of bone marrow cells from MTX-treated rats (p < 0.001). However, MTX-induced changes in bone volume, trabecular architecture, metaphyseal mRNA expression of pro-osteoclastogenic cytokines, and marrow adiposity were not significantly affected by the co-administration of genistein. This study suggests that genistein may suppress MTX-induced osteoclastogenesis; however, further studies are required to examine its potential in protecting against MTX chemotherapy-induced bone damage. PMID:26258775

  4. Estrogen Receptor Beta and 2-arachidonoylglycerol Mediate the Suppressive Effects of Estradiol on Frequency of Postsynaptic Currents in Gonadotropin-Releasing Hormone Neurons of Metestrous Mice: An Acute Slice Electrophysiological Study

    PubMed Central

    Bálint, Flóra; Liposits, Zsolt; Farkas, Imre

    2016-01-01

    Gonadotropin-releasing hormone (GnRH) neurons are controlled by 17β-estradiol (E2) contributing to the steroid feedback regulation of the reproductive axis. In rodents, E2 exerts a negative feedback effect upon GnRH neurons throughout the estrus-diestrus phase of the ovarian cycle. The present study was undertaken to reveal the role of estrogen receptor subtypes in the mediation of the E2 signal and elucidate the downstream molecular machinery of suppression. The effect of E2 administration at low physiological concentration (10 pM) on GnRH neurons in acute brain slices obtained from metestrous GnRH-green fluorescent protein (GFP) mice was studied under paradigms of blocking or activating estrogen receptor subtypes and interfering with retrograde 2-arachidonoylglycerol (2-AG) signaling. Whole-cell patch clamp recordings revealed that E2 significantly diminished the frequency of spontaneous postsynaptic currents (sPSCs) in GnRH neurons (49.62 ± 7.6%) which effect was abolished by application of the estrogen receptor (ER) α/β blocker Faslodex (1 μM). Pretreatment of the brain slices with cannabinoid receptor type 1 (CB1) inverse agonist AM251 (1 μM) and intracellularly applied endocannabinoid synthesis blocker THL (10 μM) significantly attenuated the effect of E2 on the sPSCs. E2 remained effective in the presence of tetrodotoxin (TTX) indicating a direct action of E2 on GnRH cells. The ERβ specific agonist DPN (10 pM) also significantly decreased the frequency of miniature postsynaptic currents (mPSCs) in GnRH neurons. In addition, the suppressive effect of E2 was completely blocked by the selective ERβ antagonist PHTPP (1 μM) indicating that ERβ is required for the observed rapid effect of the E2. In contrast, the ERα agonist PPT (10 pM) or the membrane-associated G protein-coupled estrogen receptor (GPR30) agonist G1 (10 pM) had no significant effect on the frequency of mPSCs in these neurons. AM251 and tetrahydrolipstatin (THL) significantly abolished

  5. Vestibular Neuronitis

    MedlinePlus

    ... Prevent Painful Swimmer's Ear Additional Content Medical News Vestibular Neuronitis By Lawrence R. Lustig, MD NOTE: This ... Drugs Herpes Zoster Oticus Meniere Disease Purulent Labyrinthitis Vestibular Neuronitis Vestibular neuronitis is a disorder characterized by ...

  6. Transporting mitochondria in neurons

    PubMed Central

    Course, Meredith M.; Wang, Xinnan

    2016-01-01

    Neurons demand vast and vacillating supplies of energy. As the key contributors of this energy, as well as primary pools of calcium and signaling molecules, mitochondria must be where the neuron needs them, when the neuron needs them. The unique architecture and length of neurons, however, make them a complex system for mitochondria to navigate. To add to this difficulty, mitochondria are synthesized mainly in the soma, but must be transported as far as the distant terminals of the neuron. Similarly, damaged mitochondria—which can cause oxidative stress to the neuron—must fuse with healthy mitochondria to repair the damage, return all the way back to the soma for disposal, or be eliminated at the terminals. Increasing evidence suggests that the improper distribution of mitochondria in neurons can lead to neurodegenerative and neuropsychiatric disorders. Here, we will discuss the machinery and regulatory systems used to properly distribute mitochondria in neurons, and how this knowledge has been leveraged to better understand neurological dysfunction. PMID:27508065

  7. Transgenic overexpression of neuroglobin attenuates formation of smoke-inhalation-induced oxidative DNA damage, in vivo, in the mouse brain.

    PubMed

    Lee, Heung Man; Greeley, George H; Englander, Ella W

    2011-12-15

    Acute inhalation of combustion smoke causes neurological deficits in survivors. Inhaled smoke includes carbon monoxide, noxious gases, and a hypoxic environment, which disrupt oxygenation and generate free radicals. To replicate a smoke-inhalation scenario, we developed an experimental model of acute exposure to smoke for the awake mouse/rat and detected induction of biomarkers of oxidative stress. These include inhibition of mitochondrial respiratory complexes and formation of oxidative DNA damage in the brain. DNA damage is likely to contribute to neuronal dysfunction and progression of brain injury. In the search for strategies to attenuate the smoke-initiated brain injury, we produced a transgenic mouse overexpressing the neuronal globin protein neuroglobin. Neuroglobin was neuroprotective in diverse models of ischemic/hypoxic/toxic brain injuries. Here, we report lesser inhibition of respiratory complex I and reduced formation of smoke-induced DNA damage in neuroglobin transgenic compared to wild-type mouse brain. DNA damage was assessed using the standard comet assay, as well as a modified comet assay done in conjunction with an enzyme that excises oxidized guanines that form readily under conditions of oxidative stress. Both comet assays revealed that overexpressed neuroglobin attenuates the formation of oxidative DNA damage, in vivo, in the brain. These findings suggest that elevated neuroglobin exerts neuroprotection, in part, by decreasing the impact of acute smoke inhalation on the integrity of neuronal DNA. PMID:22001746

  8. Neuron-Specific Enolase Is Correlated to Compromised Cerebral Metabolism in Patients Suffering from Acute Bacterial Meningitis; An Observational Cohort Study

    PubMed Central

    Bartek, Jiri; Thelin, Eric Peter; Ghatan, Per Hamid; Glimaker, Martin; Bellander, Bo-Michael

    2016-01-01

    Introduction Patients suffering from acute bacterial meningitis (ABM) with a decreased level of consciousness have been shown to have an improved clinical outcome if treated with an intracranial pressure (ICP) guided therapy. By using intracranial microdialysis (MD) to monitor cerebral metabolism in combination with serum samples of biomarkers indicating brain tissue injury, S100B and Neuron Specific Enolase (NSE), additional information might be provided. The aim of this study was to evaluate biomarkers in serum and MD parameters in patients with ABM. Methods From a prior study on patients (n = 52) with a confirmed ABM and impaired consciousness (GCS ≤ 9, or GCS = 10 combined with lumbar spinal opening pressure > 400 mmH2O), a subgroup of patients (n = 21) monitored with intracerebral MD and biomarkers was included in the present study. All patients were treated in the NICU with intracranial pressure (ICP) guided therapy. Serum biomarkers were obtained at admission and every 12 hours. The MD parameters glucose, lactate, pyruvate and glycerol were analyzed. Outcome was assessed at 12–55 months after discharge from hospital. Mann-Whitney U-Test and Wilcoxon matched-pairs signed rank test were applied. Results The included patients had a mean GCS of 8 (range, 3–10) on admission and increased ICP (>20 mmHg) was observed in 62% (n = 13/21) of the patients. Patients with a lactate:pyruvate ratio (LPR) >40 (n = 9/21, 43%) had significantly higher peak levels of serum NSE (p = 0.03), with similar, although non-significant observations made in patients with high levels of glycerol (>500 μmol/L, p = 0.11) and those with a metabolic crisis (Glucose <0.8 mmol/L, LPR >25, p = 0.09). No associations between serum S100B and MD parameters were found. Furthermore, median MD glucose levels decreased significantly between day 1 (0–24h) and day 3 (48–72h) after admission to the NICU (p = 0.0001). No correlation between MD parameters or biomarkers and outcome was found

  9. Ginseng Rb Fraction Protects Glia, Neurons and Cognitive Function in a Rat Model of Neurodegeneration

    PubMed Central

    Wang, Yan; Ling, Peng; Xie, Xin; Jiang, Chenyao; Zhang, Zhizhen; Lian, Xiao-Yuan

    2014-01-01

    The loss and injury of neurons play an important role in the onset of various neurodegenerative diseases, while both microgliosis and astrocyte loss or dysfunction are significant causes of neuronal degeneration. Previous studies have suggested that an extract enriched panaxadiol saponins from ginseng has more neuroprotective potential than the total saponins of ginseng. The present study investigated whether a fraction of highly purified panaxadiol saponins (termed as Rb fraction) was protective for both glia and neurons, especially GABAergic interneurons, against kainic acid (KA)-induced excitotoxicity in rats. Rats received Rb fraction at 30 mg/kg (ip), 40 mg/kg (ip or saline followed 40 min later by an intracerebroventricular injection of KA. Acute hippocampal injury was determined at 48 h after KA, and impairment of hippocampus-dependent learning and memory as well as delayed neuronal injury was determined 16 to 21 days later. KA injection produced significant acute hippocampal injuries, including GAD67-positive GABAergic interneuron loss in CA1, paralbumin (PV)-positive GABAergic interneuron loss, pyramidal neuron degeneration and astrocyte damage accompanied with reactive microglia in both CA1 and CA3 regions of the hippocampus. There was also a delayed loss of GAD67-positive interneurons in CA1, CA3, hilus and dentate gyrus. Microgliosis also became more severe 21 days later. Accordingly, KA injection resulted in hippocampus-dependent spatial memory impairment. Interestingly, the pretreatment with Rb fraction at 30 or 40 mg/kg significantly protected the pyramidal neurons and GABAergic interneurons against KA-induced acute excitotoxicity and delayed injury. Rb fraction also prevented memory impairments and protected astrocytes from KA-induced acute excitotoxicity. Additionally, microglial activation, especially the delayed microgliosis, was inhibited by Rb fraction. Overall, this study demonstrated that Rb fraction protected both astrocytes and neurons

  10. Mitochondrial bioenergetics and neuronal survival modelled in primary neuronal culture and isolated nerve terminals.

    PubMed

    Nicholls, David G; Brand, Martin D; Gerencser, Akos A

    2015-04-01

    Mitochondria play multiple roles in the maintenance of neuronal function under physiological and pathological conditions. In addition to ATP generation, they can act as major short-term calcium sinks and can both generate, and be damaged by, reactive oxygen species. Two complementary preparations have been extensively employed to investigate in situ neuronal mitochondrial bioenergetics, primary neuronal cultures and acutely isolated nerve terminals, synaptosomes. A major focus of the cell culture preparation has been the investigation of glutamate excitotoxicity. Oxidative phosphorylation, calcium transport and reactive oxygen species play complex interlocking roles in the life and death of the glutamate exposed neuron. Synaptosomes may be isolated from specific brain regions at any developmental stage and therefore provide a valuable ex vivo approach in studying mouse models. Recent advances have allowed synaptosomal bioenergetics to be studied on a microgram scale, and, in combination with approaches to correct for functional and transmitter heterogeneity, have allowed hypotheses concerning presynaptic mitochondrial dysfunction to be tested on a variety of genetic models of neurodegenerative disorders. PMID:25172197

  11. Duration-dependent hepatoprotective effects of propolis extract against carbon tetrachloride-induced acute liver damage in rats.

    PubMed

    Bhadauria, Monika; Nirala, Satendra Kumar; Shukla, Sangeeta

    2007-01-01

    Propolis is a natural product produced by bees that was discovered through the study of traditional cures and knowledge of indigenous people throughout the world. It is rich in vitamins A, B, C, and E, and in amino acids, copper, iron, manganese, and zinc. The investigators studied the duration-dependent hepatoprotective effects of propolis extract (200 mg/kg, orally) against carbon tetrachloride (CCl 4; 1.5 mL/kg, intraperitoneally)-induced liver damage in rats. Administration of CCl 4 caused a sharp elevation in the activity of serum transaminases and serum alkaline phosphatase. A significant depletion in hepatically reduced glutathione was observed with significantly enhanced hepatic lipid peroxidation. After CCl 4 administration, glycogen contents and activities of alkaline phosphatase, adenosine triphosphatase, and succinic dehydrogenase were significantly decreased, whereas total protein contents and activity of acid phosphatase were increased in the liver and kidney. Propolis extract reversed alterations in all parameters when administered within 6, 12, and 24 h of toxicant exposure. Propolis therapy produced duration-dependent protection, with maximal protection achieved at 24 h after CCl 4 exposure. It is believed that propolis in its natural form has general pharmacologic value and marked hepatoprotective potential because of its composition of minerals, flavonoids, and phenolic compounds. PMID:18029340

  12. Deletion of Nuclear Factor kappa B p50 Subunit Decreases Inflammatory Response and Mildly Protects Neurons from Transient Forebrain Ischemia-induced Damage.

    PubMed

    Rolova, Taisia; Dhungana, Hiramani; Korhonen, Paula; Valonen, Piia; Kolosowska, Natalia; Konttinen, Henna; Kanninen, Katja; Tanila, Heikki; Malm, Tarja; Koistinaho, Jari

    2016-08-01

    Transient forebrain ischemia induces delayed death of the hippocampal pyramidal neurons, particularly in the CA2 and medial CA1 area. Early pharmacological inhibition of inflammatory response can ameliorate neuronal death, but it also inhibits processes leading to tissue regeneration. Therefore, research efforts are now directed to modulation of post-ischemic inflammation, with the aim to promote beneficial effects of inflammation and limit adverse effects. Transcription factor NF-κB plays a key role in the inflammation and cell survival/apoptosis pathways. In the brain, NF-κB is predominantly found in the form of a heterodimer of p65 (RelA) and p50 subunit, where p65 has a transactivation domain while p50 is chiefly involved in DNA binding. In this study, we subjected middle-aged Nfkb1 knockout mice (lacking p50 subunit) and wild-type controls of both sexs to 17 min of transient forebrain ischemia and assessed mouse performance in a panel of behavioral tests after two weeks of post-operative recovery. We found that ischemia failed to induce clear memory and motor deficits, but affected spontaneous locomotion in genotype- and sex-specific way. We also show that both the lack of the NF-κB p50 subunit and female sex independently protected CA2 hippocampal neurons from ischemia-induced cell death. Additionally, the NF-κB p50 subunit deficiency significantly reduced ischemia-induced microgliosis, astrogliosis, and neurogenesis. Lower levels of hippocampal microgliosis significantly correlated with faster spatial learning. We conclude that NF-κB regulates the outcome of transient forebrain ischemia in middle-aged subjects in a sex-specific way, having an impact not only on neuronal death but also specific inflammatory responses and neurogenesis. PMID:27493832

  13. Deletion of Nuclear Factor kappa B p50 Subunit Decreases Inflammatory Response and Mildly Protects Neurons from Transient Forebrain Ischemia-induced Damage

    PubMed Central

    Rolova, Taisia; Dhungana, Hiramani; Korhonen, Paula; Valonen, Piia; Kolosowska, Natalia; Konttinen, Henna; Kanninen, Katja; Tanila, Heikki; Malm, Tarja; Koistinaho, Jari

    2016-01-01

    Transient forebrain ischemia induces delayed death of the hippocampal pyramidal neurons, particularly in the CA2 and medial CA1 area. Early pharmacological inhibition of inflammatory response can ameliorate neuronal death, but it also inhibits processes leading to tissue regeneration. Therefore, research efforts are now directed to modulation of post-ischemic inflammation, with the aim to promote beneficial effects of inflammation and limit adverse effects. Transcription factor NF-κB plays a key role in the inflammation and cell survival/apoptosis pathways. In the brain, NF-κB is predominantly found in the form of a heterodimer of p65 (RelA) and p50 subunit, where p65 has a transactivation domain while p50 is chiefly involved in DNA binding. In this study, we subjected middle-aged Nfkb1 knockout mice (lacking p50 subunit) and wild-type controls of both sexs to 17 min of transient forebrain ischemia and assessed mouse performance in a panel of behavioral tests after two weeks of post-operative recovery. We found that ischemia failed to induce clear memory and motor deficits, but affected spontaneous locomotion in genotype- and sex-specific way. We also show that both the lack of the NF-κB p50 subunit and female sex independently protected CA2 hippocampal neurons from ischemia-induced cell death. Additionally, the NF-κB p50 subunit deficiency significantly reduced ischemia-induced microgliosis, astrogliosis, and neurogenesis. Lower levels of hippocampal microgliosis significantly correlated with faster spatial learning. We conclude that NF-κB regulates the outcome of transient forebrain ischemia in middle-aged subjects in a sex-specific way, having an impact not only on neuronal death but also specific inflammatory responses and neurogenesis. PMID:27493832

  14. [Is the use of STABHA™ for supplementation of damaged extracellular matrix of soft tissues in the musculoskeletal system an effective treatment of acute injuries and tendinopathies?].

    PubMed

    Tomaszewski, Wiesław

    2015-01-01

    Viscosupplementation, or the intra articular administration of hyaluronic acid in order to stabilise synovial fluid chemistry and improve its functional quality, is now a popular therapeutic method whose efficacy, based on numerous published studies, makes it not only a form of symptomatic treatment, but also, to a considerable extent, a cause-oriented treatment. However, a possibly controversial aspect of this therapy is the use of “intra articular hyaluronate” in the treatment of post-traumatic or inflammatory soft-tissue lesions in in the musculoskeletal system. Inappropriate administration of this dosage form to the area of the injured soft tissue (Achilles tendon, periarticular tendon of tarsal joint or knee, tennis elbow, tendinopathy within the rotator cuff, etc.) may not only lead to a failure to achieve the desired therapeutic effect but can even increase the severity of the symptoms, including a rupture of the frayed tendon. The role and importance of hyaluronate in the process of natural regeneration of damaged soft tissue has been demonstrated unequivocally and beyond any doubt. Subsequent research aimed to produce forms of hyaluronic acid that would be characterised by a greater influence and support of the regeneration processes in musculoskeletal soft tissue after an acute or chronic injury, as well as to develop the technology to produce a formulation which would be biocompatible, efficient and adapted to the treatment of ligament and tendon injuries. Following administration, such formulation would also need to be identified by the body as a naturally produced hyaluronate, which plays an essential role in the repair of damaged tissue, beginning with the bleeding phase and involving in all phases of the healing process, as has been demonstrated in numerous scientific studies. The development of a technology for producing hyaluronic acid known as STABHA™ (Soft Tissue Adapted Biocompatible Hyaluronic Acid) in 2008 proved to be a significant

  15. Dopamine D3 receptors modulate the rate of neuronal recovery, cell recruitment in Area X, and song tempo after neurotoxic damage in songbirds.

    PubMed

    Lukacova, Kristina; Pavukova, Eva; Kostal, Lubor; Bilcik, Boris; Kubikova, Lubica

    2016-09-01

    Songbirds, like humans, learn vocalizations and their striatum recruits new neurons in adulthood. Injury in striatal vocal nucleus Area X, involved in song learning and production in songbirds, is followed by massive regeneration. The newborn neurons arise from the subventricular zone (SVZ) rich in dopamine D3 receptors (D3Rs). The aim of this study was to investigate whether the D3Rs affect the rate of neuronal recovery in Area X. Male zebra finches (Taeniopygia guttata) received bilateral neurotoxic lesion of Area X and were implanted with osmotic minipumps containing D3R agonist 7-OH-DPAT, antagonist U99194, or saline. Treatment with 7-OH-DPAT but not U99194 led to significant reduction of lesion size and increased numbers of migrating neuroblasts and newborn cells in the Area X. These cells were detected in the lesion border as well as the lesion center. Lesion also led to increased mRNA expression of the D3Rs in the neurogenic SVZ and in the nucleus robustus arcopallialis (RA) involved in song production. Moreover, lesion alone prolonged the song duration and this may be facilitated by D3Rs in RA. Parallel lesion and stimulation of D3Rs prolonged it even more, while blocking of D3Rs abolished the lesion-induced effect. These data suggest that D3R stimulation after striatal injury accelerates the striatal recovery and can cause behavioral alterations. PMID:27339729

  16. New Hippocampal Neurons Mature Rapidly in Response to Ketamine But Are Not Required for Its Acute Antidepressant Effects on Neophagia in Rats123

    PubMed Central

    Soumier, Amelie; Carter, Rayna M.; Schoenfeld, Timothy J.

    2016-01-01

    Abstract Virtually all antidepressant agents increase the birth of granule neurons in the adult dentate gyrus in rodents, providing a key basis for the neurogenesis hypothesis of antidepressant action. The novel antidepressant ketamine, however, shows antidepressant activity in humans within hours, far too rapid for a mechanism involving neuronal birth. Ketamine could potentially act more rapidly by enhancing maturation of new neurons born weeks earlier. To test this possibility, we assessed the effects of S-ketamine (S-(+)-ketamine hydrochloride) injection on maturation, as well as birth and survival, of new dentate gyrus granule neurons in rats, using the immediate-early gene zif268, proliferating cell nuclear antigen, and BrdU, respectively. We show that S-ketamine has rapid effects on new neurons, increasing the proportion of functionally mature young granule neurons within 2 h. A single injection of S-ketamine also increased cell proliferation and functional maturation, and decreased depressive-like behavior, for at least 4 weeks in rats treated with long-term corticosterone administration (a depression model) and controls. However, the behavioral effects of S-ketamine on neophagia were unaffected by elimination of adult neurogenesis. Together, these results indicate that ketamine has surprisingly rapid and long-lasting effects on the recruitment of young neurons into hippocampal networks, but that ketamine has antidepressant-like effects that are independent of adult neurogenesis. PMID:27066531

  17. Hydrogen peroxide modulates neuronal excitability and membrane properties in ventral horn neurons of the rat spinal cord.

    PubMed

    Ohashi, Masayuki; Hirano, Toru; Watanabe, Kei; Shoji, Hirokazu; Ohashi, Nobuko; Baba, Hiroshi; Endo, Naoto; Kohno, Tatsuro

    2016-09-01

    Hydrogen peroxide (H2O2), a reactive oxygen species, is an important signaling molecule for synaptic and neuronal activity in the central nervous system; it is produced excessively in brain ischemia and spinal cord injury. Although H2O2-mediated modulations of synaptic transmission have been reported in ventral horn (VH) neurons of the rat spinal cord, the effects of H2O2 on neuronal excitability and membrane properties remain poorly understood. Accordingly, the present study investigated such effects using a whole-cell patch-clamp technique. The bath-application of H2O2 decreased neuronal excitability accompanied by decreased input resistance, firing frequency, and action potential amplitude and by increased rheobase. These H2O2-mediated changes were induced by activation of extrasynaptic, but not synaptic, GABAA receptors. Indeed, GABAergic tonic currents were enhanced by H2O2. On the other hand, the amplitude of medium and slow afterhyperpolarization (mAHP and sAHP), which plays important roles in controlling neuronal excitability and is mediated by small-conductance calcium-activated potassium (SK) channels, was significantly decreased by H2O2. When extrasynaptic GABAA receptors were completely blocked, these decreases of mAHP and sAHP persisted, and H2O2 increased excitability, suggesting that H2O2 per se might have the potential to increase neuronal excitability via decreased SK channel conductance. These findings indicate that activating extrasynaptic GABAA receptors or SK channels may attenuate acute neuronal damage caused by H2O2-induced hyperexcitability and therefore represent a novel therapeutic target for the prevention and treatment of H2O2-induced motor neuron disorders. PMID:27343829

  18. Dimethyl Fumarate Protects Neural Stem/Progenitor Cells and Neurons from Oxidative Damage through Nrf2-ERK1/2 MAPK Pathway

    PubMed Central

    Wang, Qin; Chuikov, Sergei; Taitano, Sophina; Wu, Qi; Rastogi, Arjun; Tuck, Samuel J.; Corey, Joseph M.; Lundy, Steven K.; Mao-Draayer, Yang

    2015-01-01

    Multiple sclerosis (MS) is the most common multifocal inflammatory demyelinating disease of the central nervous system (CNS). Due to the progressive neurodegenerative nature of MS, developing treatments that exhibit direct neuroprotective effects are needed. Tecfidera™ (BG-12) is an oral formulation of the fumaric acid esters (FAE), containing the active metabolite dimethyl fumarate (DMF). Although BG-12 showed remarkable efficacy in lowering relapse rates in clinical trials, its mechanism of action in MS is not yet well understood. In this study, we reported the potential neuroprotective effects of dimethyl fumarate (DMF) on mouse and rat neural stem/progenitor cells (NPCs) and neurons. We found that DMF increased the frequency of the multipotent neurospheres and the survival of NPCs following oxidative stress with hydrogen peroxide (H2O2) treatment. In addition, utilizing the reactive oxygen species (ROS) assay, we showed that DMF reduced ROS production induced by H2O2. DMF also decreased oxidative stress-induced apoptosis. Using motor neuron survival assay, DMF significantly promoted survival of motor neurons under oxidative stress. We further analyzed the expression of oxidative stress-induced genes in the NPC cultures and showed that DMF increased the expression of transcription factor nuclear factor-erythroid 2-related factor 2 (Nrf2) at both levels of RNA and protein. Furthermore, we demonstrated the involvement of Nrf2-ERK1/2 MAPK pathway in DMF-mediated neuroprotection. Finally, we utilized SuperArray gene screen technology to identify additional anti-oxidative stress genes (Gstp1, Sod2, Nqo1, Srxn1, Fth1). Our data suggests that analysis of anti-oxidative stress mechanisms may yield further insights into new targets for treatment of multiple sclerosis (MS). PMID:26090715

  19. Dimethyl Fumarate Protects Neural Stem/Progenitor Cells and Neurons from Oxidative Damage through Nrf2-ERK1/2 MAPK Pathway.

    PubMed

    Wang, Qin; Chuikov, Sergei; Taitano, Sophina; Wu, Qi; Rastogi, Arjun; Tuck, Samuel J; Corey, Joseph M; Lundy, Steven K; Mao-Draayer, Yang

    2015-01-01

    Multiple sclerosis (MS) is the most common multifocal inflammatory demyelinating disease of the central nervous system (CNS). Due to the progressive neurodegenerative nature of MS, developing treatments that exhibit direct neuroprotective effects are needed. Tecfidera™ (BG-12) is an oral formulation of the fumaric acid esters (FAE), containing the active metabolite dimethyl fumarate (DMF). Although BG-12 showed remarkable efficacy in lowering relapse rates in clinical trials, its mechanism of action in MS is not yet well understood. In this study, we reported the potential neuroprotective effects of dimethyl fumarate (DMF) on mouse and rat neural stem/progenitor cells (NPCs) and neurons. We found that DMF increased the frequency of the multipotent neurospheres and the survival of NPCs following oxidative stress with hydrogen peroxide (H2O2) treatment. In addition, utilizing the reactive oxygen species (ROS) assay, we showed that DMF reduced ROS production induced by H2O2. DMF also decreased oxidative stress-induced apoptosis. Using motor neuron survival assay, DMF significantly promoted survival of motor neurons under oxidative stress. We further analyzed the expression of oxidative stress-induced genes in the NPC cultures and showed that DMF increased the expression of transcription factor nuclear factor-erythroid 2-related factor 2 (Nrf2) at both levels of RNA and protein. Furthermore, we demonstrated the involvement of Nrf2-ERK1/2 MAPK pathway in DMF-mediated neuroprotection. Finally, we utilized SuperArray gene screen technology to identify additional anti-oxidative stress genes (Gstp1, Sod2, Nqo1, Srxn1, Fth1). Our data suggests that analysis of anti-oxidative stress mechanisms may yield further insights into new targets for treatment of multiple sclerosis (MS). PMID:26090715

  20. COMMUNICATION: Folate and S-adenosylmethionine modulate synaptic activity in cultured cortical neurons: acute differential impact on normal and apolipoprotein-deficient mice

    NASA Astrophysics Data System (ADS)

    Serra, Michael; Chan, Amy; Dubey, Maya; Gilman, Vladimir; Shea, Thomas B.

    2008-12-01

    Folate deficiency is accompanied by a decline in the cognitive neurotransmitter acetylcholine and a decline in cognitive performance in mice lacking apolipoprotein E (ApoE-/- mice), a low-density lipoprotein that regulates aspects of lipid metabolism. One direct consequence of folate deficiency is a decline in S-adenosylmethionine (SAM). Since dietary SAM supplementation maintains acetylcholine levels and cognitive performance in the absence of folate, we examined herein the impact of folate and SAM on neuronal synaptic activity. Embryonic cortical neurons from mice expressing or lacking ApoE (ApoE+/+ or -/-, respectively) were cultured for 1 month on multi-electrode arrays, and signaling was recorded. ApoE+/+ cultures displayed significantly more frequent spontaneous signals than ApoE-/- cultures. Supplementation with 166 µm SAM (not normally present in culture medium) increased signal frequency and decreased signal amplitude in ApoE+/+ cultures. SAM also increased the frequency of tightly clustered signal bursts. Folate deprivation reversibly reduced signal frequency in ApoE+/+ cultures; SAM supplementation maintained signal frequency despite folate deprivation. These findings support the importance of dietary supplementation with folate and SAM on neuronal health. Supplementation with 166 µm SAM did not alter signaling in ApoE-/- cultures, which may be a reflection of the reduced SAM levels in ApoE-/- mice. The differential impact of SAM on ApoE+/+ and -/- neurons underscores the combined impact of nutritional and genetic deficiencies on neuronal homeostasis.

  1. Protective effects of fangchinoline and tetrandrine on hydrogen peroxide-induced oxidative neuronal cell damage in cultured rat cerebellar granule cells.

    PubMed

    Koh, Sang Bum; Ban, Ju Yeon; Lee, Bo Young; Seong, Yeon Hee

    2003-06-01

    The present study was performed to examine the neuroprotective effects of fangchinoline (FAN) and tetrandrine (TET), bis-benzylisoquinoline alkaloids, which exhibit the characteristics of Ca 2+ channel blockers, on H2O2 -induced neurotoxicity using cultured rat cerebellar granule neurons. H2O2 produced a concentration-dependent reduction of cell viability, which was blocked by (5 R,10 S)-(+)-5-methyl-10,11-dihydro-5 H-dibenzo[ a,d]cyclohepten-5,10-imine (MK-801), an N-methyl- D-aspartate (NMDA) receptor antagonist, verapamil, an L-type Ca 2+ channel blocker, and NG-nitro- L-arginine methyl ester (L-NAME), a nitric oxide synthase (NOS) inhibitor. Pretreatment with FAN and TET over a concentration range of 0.1 to 10 microM significantly decreased the H2O2 -induced neuronal cell death as assessed by a trypan blue exclusion test, a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay and the number of apoptotic nuclei. In addition, FAN and TET inhibited the H2O2 -induced elevation of glutamate release into the medium, elevation of the cytosolic free Ca 2+ concentration ([Ca 2+] c ), and generation of reactive oxygen species (ROS). These results suggest that FAN and TET may mitigate the harmful effects of H2O2 -induced neuronal cell death by interfering with the increase of [Ca 2+] c, and then by inhibiting glutamate release and generation of ROS. Abbreviations. AP5:D(-)-2-amino-5-phosphonopentanoic acid DMSO:dimethyl sulfoxide FAN:fangchinoline H 2 DCF-DA:2',7'-dichlorodihydrofluorescin diacetate MK-801:(5 R,10 S)-(+)-5-methyl-10,11-dihydro-5 H-dibenzo[ a,d]cyclohepten-5,20-imine MTT:3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide L-NAME: NG-Nitro- L-arginine methyl ester NMDA: N-methyl- D-aspartate TET:tetrandrine PMID:12865967

  2. Manganese-induced oxidative DNA damage in neuronal SH-SY5Y cells: attenuation of thymine base lesions by glutathione and N-acetylcysteine.

    PubMed

    Stephenson, Adrienne P; Schneider, Jeffrey A; Nelson, Bryant C; Atha, Donald H; Jain, Ashok; Soliman, Karam F A; Aschner, Michael; Mazzio, Elizabeth; Renee Reams, R

    2013-04-26

    Manganese (Mn) is an essential trace element required for normal function and development. However, exposure to this metal at elevated levels may cause manganism, a progressive neurodegenerative disorder with neurological symptoms similar to idiopathic Parkinson's disease (IPD). Elevated body burdens of Mn from exposure to parental nutrition, vapors in mines and smelters and welding fumes have been associated with neurological health concerns. The underlying mechanism of Mn neurotoxicity remains unclear. Accordingly, the present study was designed to investigate the toxic effects of Mn(2+) in human neuroblastoma SH-SY5Y cells. Mn(2+) caused a concentration dependent decrease in SH-SY5Y cellular viability compared to controls. The LD50 value was 12.98 μM Mn(2+) (p<0.001 for control vs. 24h Mn treatment). Both TUNEL and annexin V/propidium iodide (PI) apoptosis assays confirmed the induction of apoptosis in the cells following exposure to Mn(2+) (2 μM, 62 μM or 125 μM). In addition, Mn(2+) induced both the formation and accumulation of DNA single strand breaks (via alkaline comet assay analysis) and oxidatively modified thymine bases (via gas chromatography/mass spectrometry analysis). Pre-incubation of the cells with characteristic antioxidants, either 1mM N-acetylcysteine (NAC) or 1mM glutathione (GSH) reduced the level of DNA strand breaks and the formation of thymine base lesions, suggesting protection against oxidative cellular damage. Our findings indicate that (1) exposure of SH-SY5Y cells to Mn promotes both the formation and accumulation of oxidative DNA damage, (2) SH-SY5Y cells with accumulated DNA damage are more likely to die via an apoptotic pathway and (3) the accumulated levels of DNA damage can be abrogated by the addition of exogenous chemical antioxidants. This is the first known report of Mn(2+)-induction and antioxidant protection of thymine lesions in this SH-SY5Y cell line and contributes new information to the potential use of antioxidants

  3. The acute effect in rats of 3,4-methylenedioxyethamphetamine (MDEA, "eve") on body temperature and long term degeneration of 5-HT neurones in brain: a comparison with MDMA ("ecstasy").

    PubMed

    Colado, M I; Granados, R; O'Shea, E; Esteban, B; Green, A R

    1999-06-01

    Administration of a single dose of the recreationally used drug 3,4-methylenedioxyethamphetamine (MDEA or "eve") to Dark Agouti rats resulted in an acute dose-dependent hyperthermic response. The peak effect and duration of hyperthermia of a dose of MDEA of 35 mg/kg intraperitoneally was similar to a dose of 3,4-methylenedioxymethamphetamine (MDMA or "ecstasy") of 15 mg/kg intraperitoneally. Seven days later this dose of MDMA produced a marked (approximately 50%) loss of 5-HT and its metabolite 5-HIAA in cortex, hippocampus and striatum and a similar loss of [3H]-paroxetine binding in cortex: these losses reflecting the MDMA-induced neurotoxic degeneration of 5-HT nerve endings. In contrast, administration of MDEA (15, 25 or 35 mg/kg), even at the highest dose, produced only a 20% loss in cortex and hippocampus and no decrease in striatum. The neurotoxic effect of MDEA was only weakly dose-dependent. Neither MDEA (35 mg/kg) nor MDMA (15 mg/kg) altered striatal dopamine content 7 days later. MDEA appeared to have about half the potency of MDMA in inducing acute hyperthermia and 25% of the potency in inducing degeneration of cerebral 5-HT neurones. However since higher doses of MDEA (compared to MDMA) are probably necessary to induce mood changing effects, these data do not support any contention that this compound is a "safer" recreational drug than MDMA in terms of either acute toxicity or long term neurodegeneration. PMID:10401727

  4. Neuregulin-1 is Neuroprotective in a Rat Model of Organophosphate-Induced Delayed Neuronal Injury

    PubMed Central

    Li, Yonggang; Lein, Pamela J.; Liu, Cuimei; Bruun, Donald A.; Giulivi, Cecilia; Ford, Gregory; Tewolde, Teclemichael; Ross-Inta, Catherine; Ford, Byron D.

    2012-01-01

    Current medical countermeasures against organophosphate (OP) nerve agents are effective in reducing mortality, but do not sufficiently protect the CNS from delayed brain damage and persistent neurological symptoms. In this study, we examined the efficacy of neuregulin-1 (NRG-1) in protecting against delayed neuronal cell death following acute intoxication with the OP diisopropylfluorophosphate (DFP). Adult male Sprague Dawley rats were pretreated with pyridostigmine (0.1 mg/kg BW, i.m.) and atropine methylnitrate (20 mg/kg BW, i.m.) prior to DFP (9 mg/kg BW, i.p.) intoxication to increase survival and reduce peripheral signs of cholinergic toxicity but not prevent DFP-induced seizures or delayed neuronal injury. Pretreatment with NRG-1 did not protect against seizures in rats exposed to DFP. However, neuronal injury was significantly reduced in most brain regions by pretreatment with NRG-1 isoforms NRG-EGF (3.2 μg/kg BW, i.a) or NRG-GGF2 (48 μg/kg BW, i.a.) as determined by FluroJade-B labeling in multiple brain regions at 24 h post-DFP injection. NRG-1 also blocked apoptosis and oxidative stress-mediated protein damage in the brains of DFP-intoxicated rats. Administration of NRG-1 at 1 h after DFP injection similarly provided significant neuroprotection against delayed neuronal injury. These findings identify NRG-1 as a promising adjuvant therapy to current medical countermeasures for enhancing neuroprotection against acute OP intoxication. PMID:22583949

  5. Clinical and morphological correlations in acute ischemic stroke.

    PubMed

    Slujitoru, Anca Stefania; Enache, Andreea Lorena; Pintea, Irina Lavinia; Rolea, Elisabeta; Stocheci, Cristina Mariana; Pop, O T; Predescu, Anca

    2012-01-01

    We studied the clinical and histopathological changes in twenty-seven cases of acute ischemic stroke, aged between 65 and 75 years. All deaths occurred within 30 days after stroke. The aim of our study was to establish the clinical and histological correlations in acute ischemic stroke to detect prognostic factors. Brain lesions after acute stroke were observed in all regions. Our study describes the heterogeneity of brain injury after acute ischemic stroke with the participation of all brain components and the chronology in which these lesions develop and evolve. By histological and immunohistochemical studies, we identified neuronal, glial and vascular damage. The neurons had undergone in the area of lesion a process of necrosis, ballooning or condensation process. In the ischemic penumbra, we observed the presence of red neurons. Vascular lesions were represented by the discontinuity of capillaries, always associated with a marked perivascular edema. The following clinical and morphological correlations were established: liquefactive necrosis, astrocyte gliosis, phagocytosis phenomena are the more intense the later the death of the patient; apoptosis phenomena are the more intense the faster the death of the patient; the entire cerebral microcirculation presented microscopic modifications following the ischemic strokes, regardless of the time since the lesion occurred and the histological examination was made; the major neurological complications of the ischemic stroke - the hemorrhagic transformation phenomena, cerebral edema, were microscopically objectified, regardless of the time since the lesion occurred and the histological examination was made. PMID:23303014

  6. Renal Integrin-Linked Kinase Depletion Induces Kidney cGMP-Axis Upregulation: Consequences on Basal and Acutely Damaged Renal Function

    PubMed Central

    Cano-Peñalver, José Luis; Griera, Mercedes; García-Jerez, Andrea; Hatem-Vaquero, Marco; Ruiz-Torres, María Piedad; Rodríguez-Puyol, Diego; de Frutos, Sergio; Rodríguez-Puyol, Manuel

    2015-01-01

    Soluble guanylyl cyclase (sGC) is activated by nitric oxide (NO) and produces cGMP, which activates cGMP-dependent protein kinases (PKG) and is hydrolyzed by specific phosphodiesterases (PDE). The vasodilatory and cytoprotective capacity of cGMP-axis activation results in a therapeutic strategy for several pathologies. Integrin-linked kinase (ILK), a major scaffold protein between the extracellular matrix and intracellular signaling pathways, may modulate the expression and functionality of the cGMP-axis–related proteins. We introduce ILK as a novel modulator in renal homeostasis as well as a potential target for cisplatin (CIS)-induced acute kidney injury (AKI) improvement. We used an adult mice model of depletion of ILK (cKD-ILK), which showed basal increase of sGC and PKG expressions and activities in renal cortex when compared with wildtype (WT) littermates. Twenty-four h activation of sGC activation with NO enhanced the filtration rate in cKD-ILK. During AKI, cKD-ILK maintained the cGMP-axis upregulation with consequent filtration rates enhancement and ameliorated CIS-dependent tubular epithelial-to-mesenchymal transition and inflammation and markers. To emphasize the role of cGMP-axis upregulation due to ILK depletion, we modulated the cGMP axis under AKI in vivo and in renal cultured cells. A suboptimal dose of the PDE inhibitor ZAP enhanced the beneficial effects of the ILK depletion in AKI mice. On the other hand, CIS increased contractility-related events in cultured glomerular mesangial cells and necrosis rates in cultured tubular cells; ILK depletion protected the cells while sGC blockade with ODQ fully recovered the damage. PMID:26562149

  7. Myocardin-related transcription factor-A-overexpressing bone marrow stem cells protect cardiomyocytes and alleviate cardiac damage in a rat model of acute myocardial infarction.

    PubMed

    Zhong, Ze; Hu, Jia-Qing; Wu, Xin-Dong; Sun, Yong; Jiang, Jun

    2015-09-01

    Myocardin-related transcription factor-A (MRTF-A) can transduce biomechanical and humoral signals, which can positively modulate cardiac damage induced by acute myocardial infarction (AMI). In the clinic, bone marrow stem cell (BMSC) therapy is being increasingly utilized for AMI; however, the effects of BMSC transplantation remain to be optimized. Therefore, a novel strategy to enhance BMSC‑directed myocardial repair is particularly important. The present study was performed to assess the efficacy of MRTF‑A-overexpressing BMSCs in a rat model of AMI. Primary cardiomyocytes were prepared from neonatal Sprague-Dawley rats and BMSCs were isolated from male Sprague-Dawley rats (aged 8-12 weeks). Annexin V-phycoerythrin/7-actinomycin D staining was used to evaluate BMSC and cardiomyocyte survival after exposure to hydrogen peroxide in vitro. B-cell lymphoma 2 (Bcl-2) protein expression was measured by flow cytometric and western blot analyses. The effects of MRTF-A‑overexpressing BMSCs in a rat model of AMI were investigated by hematoxylin and eosin staining and western blot analysis of Bcl-2 expression in myocardial tissue sections. MRTF-A enhanced the migration of BMSCs, and overexpression of MRTF-A in BMSCs prevented hydrogen peroxide-induced apoptosis in primary cardiomyocytes ex vivo. In addition, co-culture of cardiomyocytes with MRTF‑A-overexpressing BMSCs inhibited hydrogen peroxide-induced apoptosis and the enhanced expression of Bcl-2. Furthermore, in vivo, enhanced cell survival was observed in the MRTF-A-modified BMSC group compared with that in the control group. These observations indicated that MRTF-A-overexpressing BMSCs have the potential to exert cardioprotective effects against hydrogen peroxide-induced injury and that treatment with MRTF‑A‑modified BMSCs is able to reverse cardiac dysfunction after AMI. PMID:26135208

  8. How microglia kill neurons.

    PubMed

    Brown, Guy C; Vilalta, Anna

    2015-12-01

    Microglia are resident brain macrophages that become inflammatory activated in most brain pathologies. Microglia normally protect neurons, but may accidentally kill neurons when attempting to limit infections or damage, and this may be more common with degenerative disease as there was no significant selection pressure on the aged brain in the past. A number of mechanisms by which activated microglia kill neurons have been identified, including: (i) stimulation of the phagocyte NADPH oxidase (PHOX) to produce superoxide and derivative oxidants, (ii) expression of inducible nitric oxide synthase (iNOS) producing NO and derivative oxidants, (iii) release of glutamate and glutaminase, (iv) release of TNFα, (v) release of cathepsin B, (vi) phagocytosis of stressed neurons, and (vii) decreased release of nutritive BDNF and IGF-1. PHOX stimulation contributes to microglial activation, but is not directly neurotoxic unless NO is present. NO is normally neuroprotective, but can react with superoxide to produce neurotoxic peroxynitrite, or in the presence of hypoxia inhibit mitochondrial respiration. Glutamate can be released by glia or neurons, but is neurotoxic only if the neurons are depolarised, for example as a result of mitochondrial inhibition. TNFα is normally neuroprotective, but can become toxic if caspase-8 or NF-κB activation are inhibited. If the above mechanisms do not kill neurons, they may still stress the neurons sufficiently to make them susceptible to phagocytosis by activated microglia. We review here whether microglial killing of neurons is an artefact, makes evolutionary sense or contributes in common neuropathologies and by what mechanisms. This article is part of a Special Issue entitled SI: Neuroprotection. PMID:26341532

  9. Beneficial effect of diosgenin as a stimulator of NGF on the brain with neuronal damage induced by Aβ-42 accumulation and neurotoxicant injection

    PubMed Central

    Koh, Eun-Kyoung; Yun, Woo-Bin; Kim, Ji-Eun; Song, Sung-Hwa; Sung, Ji-Eun; Lee, Hyun-Ah; Seo, Eun-Ji; Jee, Seung-Wan

    2016-01-01

    To investigate the beneficial effects of diosgenin (DG) on the multiple types of brain damage induced by Aβ-42 peptides and neurotoxicants, alterations in the specific aspects of brain functions were measured in trimethyltin (TMT)-injected transgenic 2576 (TG) mice that had been pretreated with DG for 21 days. Multiple types of damage were successfully induced by Aβ-42 accumulation and TMT injection into the brains of TG mice. However, DG treatment significantly reduced the number of Aβ-stained plaques and dead cells in the granule cells layer of the dentate gyrus. Significant suppression of acetylcholinesterase (AChE) activity and Bax/Bcl-2 expression was also observed in the DG treated TG mice (TG+DG group) when compared with those of the vehicle (VC) treated TG mice (TG+VC group). Additionally, the concentration of nerve growth factor (NGF) was dramatically enhanced in TG+DG group, although it was lower in the TG+VC group than the non-transgenic (nTG) group. Furthermore, the decreased phosphorylation of downstream members in the TrkA high affinity receptor signaling pathway in the TG+VC group was significantly recovered in the TG+DG group. A similar pattern was observed in p75NTR expression and JNK phosphorylation in the NGF low affinity receptor signaling pathway. Moreover, superoxide dismutase (SOD) activity was enhanced in the TG+DG group, while the level of malondialdehyde (MDA), a marker of lipid peroxidation, was lower in the TG+DG group than the TG+VC group. These results suggest that DG could exert a wide range of beneficial activities for multiple types of brain damage through stimulation of NGF biosynthesis. PMID:27382379

  10. Beneficial effect of diosgenin as a stimulator of NGF on the brain with neuronal damage induced by Aβ-42 accumulation and neurotoxicant injection.

    PubMed

    Koh, Eun-Kyoung; Yun, Woo-Bin; Kim, Ji-Eun; Song, Sung-Hwa; Sung, Ji-Eun; Lee, Hyun-Ah; Seo, Eun-Ji; Jee, Seung-Wan; Bae, Chang-Joon; Hwang, Dae-Youn

    2016-06-01

    To investigate the beneficial effects of diosgenin (DG) on the multiple types of brain damage induced by Aβ-42 peptides and neurotoxicants, alterations in the specific aspects of brain functions were measured in trimethyltin (TMT)-injected transgenic 2576 (TG) mice that had been pretreated with DG for 21 days. Multiple types of damage were successfully induced by Aβ-42 accumulation and TMT injection into the brains of TG mice. However, DG treatment significantly reduced the number of Aβ-stained plaques and dead cells in the granule cells layer of the dentate gyrus. Significant suppression of acetylcholinesterase (AChE) activity and Bax/Bcl-2 expression was also observed in the DG treated TG mice (TG+DG group) when compared with those of the vehicle (VC) treated TG mice (TG+VC group). Additionally, the concentration of nerve growth factor (NGF) was dramatically enhanced in TG+DG group, although it was lower in the TG+VC group than the non-transgenic (nTG) group. Furthermore, the decreased phosphorylation of downstream members in the TrkA high affinity receptor signaling pathway in the TG+VC group was significantly recovered in the TG+DG group. A similar pattern was observed in p75(NTR) expression and JNK phosphorylation in the NGF low affinity receptor signaling pathway. Moreover, superoxide dismutase (SOD) activity was enhanced in the TG+DG group, while the level of malondialdehyde (MDA), a marker of lipid peroxidation, was lower in the TG+DG group than the TG+VC group. These results suggest that DG could exert a wide range of beneficial activities for multiple types of brain damage through stimulation of NGF biosynthesis. PMID:27382379

  11. Leptin gene therapy attenuates neuronal damages evoked by amyloid-β and rescues memory deficits in APP/PS1 mice.

    PubMed

    Pérez-González, R; Alvira-Botero, M X; Robayo, O; Antequera, D; Garzón, M; Martín-Moreno, A M; Brera, B; de Ceballos, M L; Carro, E

    2014-03-01

    There is growing evidence that leptin is able to ameliorate Alzheimer's disease (AD)-like pathologies, including brain amyloid-β (Aβ) burden. In order to improve the therapeutic potential for AD, we generated a lentivirus vector expressing leptin protein in a self-inactivating HIV-1 vector (HIV-leptin), and delivered this by intra-cerebroventricular administration to APP/PS1 transgenic model of AD. Three months after intra-cerebroventricular administration of HIV-leptin, brain Aβ accumulation was reduced. By electron microscopy, we found that APP/PS1 mice exhibited deficits in synaptic density, which were partially rescued by HIV-leptin treatment. Synaptic deficits in APP/PS1 mice correlated with an enhancement of caspase-3 expression, and a reduction in synaptophysin levels in synaptosome preparations. Notably, HIV-leptin therapy reverted these dysfunctions. Moreover, leptin modulated neurite outgrowth in primary neuronal cultures, and rescued them from Aβ42-induced toxicity. All the above changes suggest that leptin may affect multiple aspects of the synaptic status, and correlate with behavioral improvements. Our data suggest that leptin gene delivery has a therapeutic potential for Aβ-targeted treatment of mouse model of AD. PMID:24430238

  12. Resveratrol protects CA1 neurons against focal cerebral ischemic reperfusion-induced damage via the ERK-CREB signaling pathway in rats.

    PubMed

    Li, Zhen; Fang, Fang; Wang, Yuanyin; Wang, Liecheng

    2016-01-01

    Ischemic stroke is a primary cause of mortality and disability in the aged population. Resveratrol (Res), a natural polyphenol enriched in plants, presents diverse biological activities, e.g., antiinflammatory and anti-oxidation effects. Here, we evaluated whether Res pretreatment influenced focal cerebral ischemia-induced cognitive impairment, and we explored the underlying mechanisms in rats. The results showed that a single administration of Res (30mg/kg, i.p.) at 1 or 4h, but not at 24h before focal cerebral ischemia exerted significant neuroprotective effects, including a reduction in hippocampal CA1 neuronal death and spatial cognition deficits caused by ischemia. The neuroprotective effects of Res were suppressed by pretreatment with MK801, an NMDA receptor blocker, or U0126, an extracellular signal regulated kinase 1/2 (ERK1/2) kinase inhibitor. A western blot analysis revealed that Res treatment at 1h before ischemia significantly increased ERK1/2 phosphorylation and cyclic-AMP response element binding protein (CREB) phosphorylation in the CA1 region of the hippocampus, which can be prevented with U0126 pretreatment. The results showed that the NMDA receptor-mediated ERK-CREB signaling pathway might participates in Res-induced neuroprotection in rats with focal cerebral ischemia. PMID:27143440

  13. Dietary Sutherlandia and Elderberry Mitigate Cerebral Ischemia-Induced Neuronal Damage and Attenuate p47phox and Phospho-ERK1/2 Expression in Microglial Cells

    PubMed Central

    Chuang, Dennis Y.; Cui, Jiankun; Simonyi, Agnes; Engel, Victoria A.; Chen, Shanyan; Fritsche, Kevin L.; Thomas, Andrew L.; Applequist, Wendy L.; Folk, William R.; Lubahn, Dennis B.; Sun, Albert Y.; Sun, Grace Y.

    2014-01-01

    Sutherlandia (Sutherlandia frutescens) and elderberry (Sambucus spp.) are used to promote health and for treatment of a number of ailments. Although studies with cultured cells have demonstrated antioxidative and anti-inflammatory properties of these botanicals, little is known about their ability to mitigate brain injury. In this study, C57BL/6 J male mice were fed AIN93G diets without or with Sutherlandia or American elderberry for 2 months prior to a 30-min global cerebral ischemia induced by occlusion of the bilateral common carotid arteries (BCCAs), followed by reperfusion for 3 days. Accelerating rotarod assessment at 24 h after BCCA occlusion showed amelioration of sensorimotor impairment in the mice fed the supplemented diets as compared with the ischemic mice fed the control diet. Quantitative digital pathology assessment of brain slides stained with cresyl violet at 3 days after ischemia/reperfusion (I/R) revealed significant reduction in neuronal cell death in both dietary groups. Immunohistochemical staining for ionized calcium-binding adapter molecule-1 demonstrated pronounced activation of microglia in the hippocampus and striatum in the ischemic brains 3 days after I/R, and microglial activation was significantly reduced in animals fed supplemented diets. Mitigation of microglial activation by the supplements was further supported by the decrease in expression of p47phox, a cytosolic subunit of NADPH oxidase, and phospho-ERK1/2, a mitogen-activated protein kinase known to mediate a number of cytoplasmic processes including oxidative stress and neuroinflammatory responses. These results demonstrate neuroprotective effect of Sutherlandia and American elderberry botanicals against oxidative and inflammatory responses to cerebral I/R. PMID:25324465

  14. Tempol moderately extends survival in a hSOD1(G93A) ALS rat model by inhibiting neuronal cell loss, oxidative damage and levels of non-native hSOD1(G93A) forms.

    PubMed

    Linares, Edlaine; Seixas, Luciana V; dos Prazeres, Janaina N; Ladd, Fernando V L; Ladd, Aliny A B L; Coppi, Antonio A; Augusto, Ohara

    2013-01-01

    Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the progressive dysfunction and death of motor neurons by mechanisms that remain unclear. Evidence indicates that oxidative mechanisms contribute to ALS pathology, but classical antioxidants have not performed well in clinical trials. Cyclic nitroxides are an alternative worth exploring because they are multifunctional antioxidants that display low toxicity in vivo. Here, we examine the effects of the cyclic nitroxide tempol (4-hydroxy-2,2,6,6-tetramethyl piperidine-1-oxyl) on ALS onset and progression in transgenic female rats over-expressing the mutant hSOD1(G93A) . Starting at 7 weeks of age, a high dose of tempol (155 mg/day/rat) in the rat´s drinking water had marginal effects on the disease onset but decelerated disease progression and extended survival by 9 days. In addition, tempol protected spinal cord tissues as monitored by the number of neuronal cells, and the reducing capability and levels of carbonylated proteins and non-native hSOD1 forms in spinal cord homogenates. Intraperitoneal tempol (26 mg/rat, 3 times/week) extended survival by 17 days. This group of rats, however, diverted to a decelerated disease progression. Therefore, it was inconclusive whether the higher protective effect of the lower i.p. dose was due to higher tempol bioavailability, decelerated disease development or both. Collectively, the results show that tempol moderately extends the survival of ALS rats while protecting their cellular and molecular structures against damage. Thus, the results provide proof that cyclic nitroxides are alternatives worth to be further tested in animal models of ALS. PMID:23405225

  15. Tempol Moderately Extends Survival in a hSOD1G93A ALS Rat Model by Inhibiting Neuronal Cell Loss, Oxidative Damage and Levels of Non-Native hSOD1G93A Forms

    PubMed Central

    Linares, Edlaine; Seixas, Luciana V.; dos Prazeres, Janaina N.; Ladd, Fernando V. L.; Ladd, Aliny A. B. L.; Coppi, Antonio A.; Augusto, Ohara

    2013-01-01

    Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the progressive dysfunction and death of motor neurons by mechanisms that remain unclear. Evidence indicates that oxidative mechanisms contribute to ALS pathology, but classical antioxidants have not performed well in clinical trials. Cyclic nitroxides are an alternative worth exploring because they are multifunctional antioxidants that display low toxicity in vivo. Here, we examine the effects of the cyclic nitroxide tempol (4-hydroxy-2,2,6,6-tetramethyl piperidine-1-oxyl) on ALS onset and progression in transgenic female rats over-expressing the mutant hSOD1G93A . Starting at 7 weeks of age, a high dose of tempol (155 mg/day/rat) in the rat´s drinking water had marginal effects on the disease onset but decelerated disease progression and extended survival by 9 days. In addition, tempol protected spinal cord tissues as monitored by the number of neuronal cells, and the reducing capability and levels of carbonylated proteins and non-native hSOD1 forms in spinal cord homogenates. Intraperitoneal tempol (26 mg/rat, 3 times/week) extended survival by 17 days. This group of rats, however, diverted to a decelerated disease progression. Therefore, it was inconclusive whether the higher protective effect of the lower i.p. dose was due to higher tempol bioavailability, decelerated disease development or both. Collectively, the results show that tempol moderately extends the survival of ALS rats while protecting their cellular and molecular structures against damage. Thus, the results provide proof that cyclic nitroxides are alternatives worth to be further tested in animal models of ALS. PMID:23405225

  16. Neuregulin-1 is neuroprotective in a rat model of organophosphate-induced delayed neuronal injury

    SciTech Connect

    Li, Yonggang; Lein, Pamela J.; Liu, Cuimei; Bruun, Donald A.; Giulivi, Cecilia; Ford, Gregory D.; Tewolde, Teclemichael; Ross-Inta, Catherine; Ford, Byron D.

    2012-07-15

    Current medical countermeasures against organophosphate (OP) nerve agents are effective in reducing mortality, but do not sufficiently protect the CNS from delayed brain damage and persistent neurological symptoms. In this study, we examined the efficacy of neuregulin-1 (NRG-1) in protecting against delayed neuronal cell death following acute intoxication with the OP diisopropylflurophosphate (DFP). Adult male Sprague–Dawley rats were pretreated with pyridostigmine (0.1 mg/kg BW, i.m.) and atropine methylnitrate (20 mg/kg BW, i.m.) prior to DFP (9 mg/kg BW, i.p.) intoxication to increase survival and reduce peripheral signs of cholinergic toxicity but not prevent DFP-induced seizures or delayed neuronal injury. Pretreatment with NRG-1 did not protect against seizures in rats exposed to DFP. However, neuronal injury was significantly reduced in most brain regions by pretreatment with NRG-1 isoforms NRG-EGF (3.2 μg/kg BW, i.a) or NRG-GGF2 (48 μg/kg BW, i.a.) as determined by FluroJade-B labeling in multiple brain regions at 24 h post-DFP injection. NRG-1 also blocked apoptosis and oxidative stress-mediated protein damage in the brains of DFP-intoxicated rats. Administration of NRG-1 at 1 h after DFP injection similarly provided significant neuroprotection against delayed neuronal injury. These findings identify NRG-1 as a promising adjuvant therapy to current medical countermeasures for enhancing neuroprotection against acute OP intoxication. -- Highlights: ► NRG-1 blocked DFP induced neuronal injury. ► NRG-1 did not protect against seizures in rats exposed to DFP. ► NRG-1 blocked apoptosis and oxidative stress in the brains of DFP-intoxicated rats. ► Administration of NRG-1 at 1 h after DFP injection prevented delayed neuronal injury.

  17. Pharyngeal pumping inhibition and avoidance by acute exposure to high CO2 levels are both regulated by the BAG neurons via different molecular pathways.

    PubMed

    Sharabi, Kfir; Charar, Chayki; Gruenbaum, Yosef

    2015-01-01

    Carbon dioxide (CO2) is a key molecule in many biological processes. Studies in humans, mice, D. melanogaster, C. elegans, unicellular organisms and plants have shed light on the molecular pathways activated by elevated levels of CO2. However, the mechanisms that organisms use to sense and respond to high CO2 levels remain largely unknown. Previous work has shown that C. elegans quickly avoid elevated CO2 levels using mechanisms that involve the BAG, ASE and AFD neurons via cGMP- and calcium- signaling pathways. Here, we discuss our recent finding that exposure of C. elegans to high CO2 levels leads to a very rapid cessation in the contraction of the pharynx muscles. Surprisingly, none of the tested CO2 avoidance mutants affected the rapid pumping inhibition response to elevated CO2 levels. A forward genetic screen identified that the hid-1-mediated pathway of dense core vesicle maturation regulates the pumping inhibition, probably through affecting neuropeptide secretion. Genetic studies and laser ablation experiments showed that the CO2 response of the pharyngeal muscle pumping is regulated by the BAG neurons, the same neurons that mediate CO2 avoidance. PMID:26430557

  18. Role of autophagy inhibitors and inducers in modulating the toxicity of trimethyltin in neuronal cell cultures.

    PubMed

    Fabrizi, C; Somma, F; Pompili, E; Biagioni, F; Lenzi, P; Fornai, F; Fumagalli, L

    2012-11-01

    Trimethyltin (TMT) is a triorganotin compound which determines neurodegeneration of specific brain areas particularly damaging the limbic system. Earlier ultrastructural studies indicated the formation of autophagic vacuoles in neurons after TMT intoxication. However, no evaluation has been attempted to determine the role of the autophagic pathway in TMT neurotoxicity. To assess the contribution of autophagy to TMT-induced neuronal cell death, we checked the vulnerability of neuronal cultures to TMT after activation or inhibition of autophagy. Our results show that autophagy inhibitors (3-methyladenine and L-asparagine) greatly enhanced TMT neurotoxicity. Conversely, known activators of autophagy, such as lithium and rapamycin, displayed neuroprotection against this toxic compound. Due to its diverse targets, the action of lithium was complex. When lithium was administered according to a chronic treatment protocol (6 days pretreatment) it was able to rescue both hippocampal and cortical neurons from TMT (or from glutamate toxicity used as reference). This effect was accompanied by an increased phosphorylation of glycogen synthase kinase 3 which is a known target for lithium neuroprotection. If the pre-incubation time was reduced to 2 h (acute treatment protocol), lithium was still able to counteract TMT toxicity in hippocampal but not in cortical neurons. The neuroprotective effect of lithium acutely administered against TMT in hippocampal neurons can be completely reverted by an excess of inositol and is possibly related to the inactivation of inositol monophosphatase, a key regulator of autophagy. These data indicate that TMT neurotoxicity can be dramatically modified, at least in vitro, by lithium addition which seems to act through different mechanisms if acutely or chronically administered. PMID:22415064

  19. Polyphenolic Antioxidants and Neuronal Regeneration.

    PubMed