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Sample records for acute neuronal death

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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

  6. [Caenorhabditis elegans and neuronal death in mammals].

    PubMed

    Selimi, F; Mariani, J; Martinou, J C

    1997-09-01

    The development of the nervous system implies not only the generation of neurons, but also their death. This neuronal death can occur through several mechanisms, one of them being apoptosis. This type of cell death seems to be also implicated in some neurodegenerative diseases. This study of the nematode Caenorhabditis elegans has led to the discovery of several genes controlling apoptosis in neurons. Two of them, the pro-apoptotic ced3 and the anti-apoptotic ced9, have mammalian homologs. The mammalian homologs to Ced9 form the Bcl-2 family and can be either pro-apoptotic or anti-apoptotic. Some of them, Bcl-x, and Bax have been shown to be involved in neuronal death during development in some pathological situations. The first mammalian homolog of Ced3 to be described was the Interleukin-1b Converting Enzymes (ICE). Since then, many other homologs of the proteases Ced3 and ICE have been discovered constituting the Caspases family. These Cysteinyl Aspartate Specific Proteases are pro-apoptotic in many different systems. Several studies using viral or peptidic inhibitors of the Caspases have demonstrated their role in neuronal death in vitro. In vivo, CPP32, a member of the Caspases family, has been shown to be clearly involved in the development of the nervous system. Finally, the analysis of apoptosis in Caenorhabditis elegans has led to the discovery of two families of genes involved in the cascade of events inducing neuronal death in mammals. Indeed, the Caspases seem to be controlled by the Bcl-2 family, as Ced3 is by Ced9. PMID:9683996

  7. TRPM7, the cytoskeleton and neuronal death

    PubMed Central

    Asrar, Suhail; Aarts, Michelle

    2013-01-01

    Ischemic stroke is one of the leading causes of disability and death in the world. Elucidation of the underlying mechanisms associated with neuronal death during this detrimental process has been of significant interest in the field of research. One principle component vital to the maintenance of cellular integrity is the cytoskeleton. Studies suggest that abnormalities at the level of this fundamental structure are directly linked to adverse effects on cellular well-being, including cell death. In recent years, evidence has also emerged regarding an imperative role for the transient receptor potential (TRP) family member TRPM7 in the mediation of excitotoxic-independent neuronal demise. In this review, we will elaborate on the current knowledge and unique properties associated with the functioning of this structure. In addition, we will deliberate the involvement of distinct mechanistic pathways during TRPM7-dependent cell death, including modifications at the level of the cytoskeleton. PMID:23247582

  8. Prevention of hypoglycemia-induced neuronal death by minocycline.

    PubMed

    Won, Seok Joon; Kim, Jin Hee; Yoo, Byung Hoon; Sohn, Min; Kauppinen, Tiina M; Park, Man-Seong; Kwon, Hyung-Joo; Liu, Jialing; Suh, Sang Won

    2012-01-01

    Diabetic patients who attempt strict management of blood glucose levels frequently experience hypoglycemia. Severe and prolonged hypoglycemia causes neuronal death and cognitive impairment. There is no effective tool for prevention of these unwanted clinical sequelae. Minocycline, a second-generation tetracycline derivative, has been recognized as an anti-inflammatory and neuroprotective agent in several animal models such as stroke and traumatic brain injury. In the present study, we tested whether minocycline also has protective effects on hypoglycemia-induced neuronal death and cognitive impairment. To test our hypothesis we used an animal model of insulin-induced acute hypoglycemia. Minocycline was injected intraperitoneally at 6 hours after hypoglycemia/glucose reperfusion and injected once per day for the following 1 week. Histological evaluation for neuronal death and microglial activation was performed from 1 day to 1 week after hypoglycemia. Cognitive evaluation was conducted 6 weeks after hypoglycemia. Microglial activation began to be evident in the hippocampal area at 1 day after hypoglycemia and persisted for 1 week. Minocycline injection significantly reduced hypoglycemia-induced microglial activation and myeloperoxidase (MPO) immunoreactivity. Neuronal death was significantly reduced by minocycline treatment when evaluated at 1 week after hypoglycemia. Hypoglycemia-induced cognitive impairment is also significantly prevented by the same minocycline regimen when subjects were evaluated at 6 weeks after hypoglycemia. Therefore, these results suggest that delayed treatment (6 hours post-insult) with minocycline protects against microglial activation, neuronal death and cognitive impairment caused by severe hypoglycemia. The present study suggests that minocycline has therapeutic potential to prevent hypoglycemia-induced brain injury in diabetic patients. PMID:22998689

  9. 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

  10. Neuronal death: where does the end begin?

    PubMed

    Conforti, Laura; Adalbert, Robert; Coleman, Michael P

    2007-04-01

    Neurodegenerative disorders involve death of cell bodies, axons, dendrites and synapses, but it is surprisingly difficult to determine the spatiotemporal sequence of events and the causal relationships among these events. Neuronal compartments often crucially depend upon one another for survival, and molecular defects in one compartment can trigger cellular degeneration in distant parts of the neuron. Here, we consider the novel approaches used to understand these biologically complex and technically challenging questions in amyotrophic lateral sclerosis, spinal muscular atrophy, glaucoma, Alzheimer's disease, Parkinson's disease and polyglutamine disorders. We conclude that there is partial understanding of what degenerates first and why, but that controversy remains the rule not the exception. Finally, we highlight strategies for resolving these fundamental issues. PMID:17339056

  11. α-Synuclein and neuronal cell death

    PubMed Central

    Cookson, Mark R

    2009-01-01

    α-Synuclein is a small protein that has special relevance for understanding Parkinson disease and related disorders. Not only is α-synuclein found in Lewy bodies characteristic of Parkinson disease, but also mutations in the gene for α-synuclein can cause an inherited form of Parkinson disease and expression of normal α-synuclein can increase the risk of developing Parkinson disease in sporadic, or non-familial, cases. Both sporadic and familial Parkinson disease are characterized by substantial loss of several groups of neurons, including the dopaminergic cells of the substantia nigra that are the target of most current symptomatic therapies. Therefore, it is predicted that α-synuclein, especially in its mutant forms or under conditions where its expression levels are increased, is a toxic protein in the sense that it is associated with an increased rate of neuronal cell death. This review will discuss the experimental contexts in which α-synuclein has been demonstrated to be toxic. I will also outline what is known about the mechanisms by which α-synuclein triggers neuronal damage, and identify some of the current gaps in our knowledge about this subject. Finally, the therapeutic implications of toxicity of α-synuclein will be discussed. PMID:19193223

  12. Neuronal gap junctions play a role in the secondary neuronal death following controlled cortical impact.

    PubMed

    Belousov, Andrei B; Wang, Yongfu; Song, Ji-Hoon; Denisova, Janna V; Berman, Nancy E; Fontes, Joseph D

    2012-08-22

    In the mammalian CNS, excessive release of glutamate and overactivation of glutamate receptors are responsible for the secondary (delayed) neuronal death following neuronal injury, including ischemia, traumatic brain injury (TBI) and epilepsy. Recent studies in mice showed a critical role for neuronal gap junctions in NMDA receptor-mediated excitotoxicity and ischemia-mediated neuronal death. Here, using controlled cortical impact (CCI) in adult mice, as a model of TBI, and Fluoro-Jade B staining for analysis of neuronal death, we set to determine whether neuronal gap junctions play a role in the CCI-mediated secondary neuronal death. We report that 24h post-CCI, substantial neuronal death is detected in a number of brain regions outside the injury core, including the striatum. The striatal neuronal death is reduced both in wild-type mice by systemic administration of mefloquine (a relatively selective blocker of neuronal gap junctions) and in knockout mice lacking connexin 36 (neuronal gap junction protein). It is also reduced by inactivation of group II metabotropic glutamate receptors (with LY341495) which, as reported previously, control the rapid increase in neuronal gap junction coupling following different types of neuronal injury. The results suggest that neuronal gap junctions play a critical role in the CCI-induced secondary neuronal death. PMID:22781494

  13. Life and death of neurons in the aging brain

    NASA Technical Reports Server (NTRS)

    Morrison, J. H.; Hof, P. R.; Bloom, F. E. (Principal Investigator)

    1997-01-01

    Neurodegenerative disorders are characterized by extensive neuron death that leads to functional decline, but the neurobiological correlates of functional decline in normal aging are less well defined. For decades, it has been a commonly held notion that widespread neuron death in the neocortex and hippocampus is an inevitable concomitant of brain aging, but recent quantitative studies suggest that neuron death is restricted in normal aging and unlikely to account for age-related impairment of neocortical and hippocampal functions. In this article, the qualitative and quantitative differences between aging and Alzheimer's disease with respect to neuron loss are discussed, and age-related changes in functional and biochemical attributes of hippocampal circuits that might mediate functional decline in the absence of neuron death are explored. When these data are viewed comprehensively, it appears that the primary neurobiological substrates for functional impairment in aging differ in important ways from those in neurodegenerative disorders such as Alzheimer's disease.

  14. Neuronal cell death in nervous system development, disease, and injury (Review).

    PubMed

    Martin, L J

    2001-05-01

    Neuronal death is normal during nervous system development but is abnormal in brain and spinal cord disease and injury. Apoptosis and necrosis are types of cell death. They are generally considered to be distinct forms of cell death. The re-emergence of apoptosis may contribute to the neuronal degeneration in chronic neurodegenerative disease, such as amyotrophic lateral sclerosis and Alzheimer's disease, and in neurological injury such as cerebral ischemia and trauma. There is also mounting evidence supporting an apoptosis-necrosis cell death continuum. In this continuum, neuronal death can result from varying contributions of coexisting apoptotic and necrotic mechanisms; thus, some of the distinctions between apoptosis and necrosis are becoming blurred. Cell culture and animal model systems are revealing the mechanisms of cell death. Necrosis can result from acute oxidative stress. Apoptosis can be induced by cell surface receptor engagement, growth factor withdrawal, and DNA damage. Several families of proteins and specific biochemical signal-transduction pathways regulate cell death. Cell death signaling can involve plasma membrane death receptors, mitochondrial death proteins, proteases, kinases, and transcription factors. Players in the cell death and cell survival orchestra include Fas receptor, Bcl-2 and Bax (and their homologues), cytochrome c, caspases, p53, and extracellular signal-regulated protein kinases. Some forms of cell death require gene activation, RNA synthesis, and protein synthesis, whereas others forms are transcriptionally-translationally-independent and are driven by posttranslational mechanisms such as protein phosphorylation and protein translocation. A better understanding of the molecular mechanisms of neuronal cell death in nervous system development, injury and disease can lead to new therapeutic approaches for the prevention of neurodegeneration and neurological disabilities and will expand the field of cell death biology. PMID

  15. Death of Neurons following Injury Requires Conductive Neuronal Gap Junction Channels but Not a Specific Connexin.

    PubMed

    Fontes, Joseph D; Ramsey, Jon; Polk, Jeremy M; Koop, Andre; Denisova, Janna V; Belousov, Andrei B

    2015-01-01

    Pharmacological blockade or genetic knockout of neuronal connexin 36 (Cx36)-containing gap junctions reduces neuronal death caused by ischemia, traumatic brain injury and NMDA receptor (NMDAR)-mediated excitotoxicity. However, whether Cx36 gap junctions contribute to neuronal death via channel-dependent or channel-independent mechanism remains an open question. To address this, we manipulated connexin protein expression via lentiviral transduction of mouse neuronal cortical cultures and analyzed neuronal death twenty-four hours following administration of NMDA (a model of NMDAR excitotoxicity) or oxygen-glucose deprivation (a model of ischemic injury). In cultures prepared from wild-type mice, over-expression and knockdown of Cx36-containing gap junctions augmented and prevented, respectively, neuronal death from NMDAR-mediated excitotoxicity and ischemia. In cultures obtained form from Cx36 knockout mice, re-expression of functional gap junction channels, containing either neuronal Cx36 or non-neuronal Cx43 or Cx31, resulted in increased neuronal death following insult. In contrast, the expression of communication-deficient gap junctions (containing mutated connexins) did not have this effect. Finally, the absence of ethidium bromide uptake in non-transduced wild-type neurons two hours following NMDAR excitotoxicity or ischemia suggested the absence of active endogenous hemichannels in those neurons. Taken together, these results suggest a role for neuronal gap junctions in cell death via a connexin type-independent mechanism that likely relies on channel activities of gap junctional complexes among neurons. A possible contribution of gap junction channel-permeable death signals in neuronal death is discussed. PMID:26017008

  16. Death of Neurons following Injury Requires Conductive Neuronal Gap Junction Channels but Not a Specific Connexin

    PubMed Central

    Fontes, Joseph D.; Ramsey, Jon; Polk, Jeremy M; Koop, Andre; Denisova, Janna V.; Belousov, Andrei B.

    2015-01-01

    Pharmacological blockade or genetic knockout of neuronal connexin 36 (Cx36)-containing gap junctions reduces neuronal death caused by ischemia, traumatic brain injury and NMDA receptor (NMDAR)-mediated excitotoxicity. However, whether Cx36 gap junctions contribute to neuronal death via channel-dependent or channel-independent mechanism remains an open question. To address this, we manipulated connexin protein expression via lentiviral transduction of mouse neuronal cortical cultures and analyzed neuronal death twenty-four hours following administration of NMDA (a model of NMDAR excitotoxicity) or oxygen-glucose deprivation (a model of ischemic injury). In cultures prepared from wild-type mice, over-expression and knockdown of Cx36-containing gap junctions augmented and prevented, respectively, neuronal death from NMDAR-mediated excitotoxicity and ischemia. In cultures obtained form from Cx36 knockout mice, re-expression of functional gap junction channels, containing either neuronal Cx36 or non-neuronal Cx43 or Cx31, resulted in increased neuronal death following insult. In contrast, the expression of communication-deficient gap junctions (containing mutated connexins) did not have this effect. Finally, the absence of ethidium bromide uptake in non-transduced wild-type neurons two hours following NMDAR excitotoxicity or ischemia suggested the absence of active endogenous hemichannels in those neurons. Taken together, these results suggest a role for neuronal gap junctions in cell death via a connexin type-independent mechanism that likely relies on channel activities of gap junctional complexes among neurons. A possible contribution of gap junction channel-permeable death signals in neuronal death is discussed. PMID:26017008

  17. 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

  18. Independent controls for neocortical neuron production and histogenetic cell death

    NASA Technical Reports Server (NTRS)

    Verney, C.; Takahashi, T.; Bhide, P. G.; Nowakowski, R. S.; Caviness, V. S. Jr

    2000-01-01

    We estimated the proportion of cells eliminated by histogenetic cell death during the first 2 postnatal weeks in areas 1, 3 and 40 of the mouse parietal neocortex. For each layer and for the subcortical white matter in each neocortical area, the number of dying cells per mm(2) was calculated and the proportionate cell death for each day of the 2-week interval was estimated. The data show that cell death proceeds essentially uniformly across the neocortical areas and layers and that it does not follow either the spatiotemporal gradient of cell cycle progression in the pseudostratified ventricular epithelium of the cerebral wall, the source of neocortical neurons, or the 'inside-out' neocortical neuronogenetic sequence. Therefore, we infer that the control mechanisms of neocortical histogenetic cell death are independent of mechanisms controlling neuronogenesis or neuronal migration but may be associated with the ingrowth, expansion and a system-wide matching of neuronal connectivity. Copyright 2000 S. Karger AG, Basel.

  19. Astrogliosis is a possible player in preventing delayed neuronal death.

    PubMed

    Jeong, Hey-Kyeong; Ji, Kyung-Min; Min, Kyoung-Jin; Choi, Insup; Choi, Dong-Joo; Jou, Ilo; Joe, Eun-Hye

    2014-04-01

    Mitigating secondary delayed neuronal injury has been a therapeutic strategy for minimizing neurological symptoms after several types of brain injury. Interestingly, secondary neuronal loss appeared to be closely related to functional loss and/or death of astrocytes. In the brain damage induced by agonists of two glutamate receptors, N-ethyl-D-aspartic acid (NMDA) and kainic acid (KA), NMDA induced neuronal death within 3 h, but did not increase further thereafter. However, in the KA-injected brain, neuronal death was not obviously detectable even at injection sites at 3 h, but extensively increased to encompass the entire hemisphere at 7 days. Brain inflammation, a possible cause of secondary neuronal damage, showed little differences between the two models. Importantly, however, astrocyte behavior was completely different. In the NMDA-injected cortex, the loss of glial fibrillary acidic protein-expressing (GFAP+) astrocytes was confined to the injection site until 7 days after the injection, and astrocytes around the damage sites showed extensive gliosis and appeared to isolate the damage sites. In contrast, in the KA-injected brain, GFAP+ astrocytes, like neurons, slowly, but progressively, disappeared across the entire hemisphere. Other markers of astrocytes, including S100β, glutamate transporter EAAT2, the potassium channel Kir4.1 and glutamine synthase, showed patterns similar to that of GFAP in both NMDA- and KA-injected cortexes. More importantly, astrocyte disappearance and/or functional loss preceded neuronal death in the KA-injected brain. Taken together, these results suggest that loss of astrocyte support to neurons may be a critical cause of delayed neuronal death in the injured brain. PMID:24802057

  20. Human neuromelanin: an endogenous microglial activator for dopaminergic neuron death

    PubMed Central

    Zhang, Wei; Zecca, Luigi; Wilson, Belinda; Ren, RW; Wang, Yong-jun; Wang, Xiao-min; Hong, Jau-Shyong

    2013-01-01

    Substantial evidence indicates that neuroinflammation caused by over-activation of microglial in the substantia nigra is critical in the pathogenesis of dopaminergic neurodegeneration in Parkinson’s disease (PD). Increasing data demonstrates that environmental factors such as rotenone, paraquat play pivotal roles in the death of dopaminergic neurons. Here, potential role and mechanism of neuromelanin (NM), a major endogenous component in dopaminergic neurons of the substantia nigra, on microglial activation and associated dopaminergic neurotoxicity were investigated. Using multiple well-established primary mesencephalic cultures, we tested whether human NM (HNM) could activate microglia, thereby provoking dopaminergic neurodegeneration. The results demonstrated that in primary mesencephalic neuron-glia cultures, HNM caused dopaminergic neuronal damage characterized by the decreased dopamine uptake and reduced numbers and shorted dendrites of dopaminergic neurons. HNM-induced degeneration was relatively selective to dopaminergic neurons since the other types of neurons determined by either gamma-aminobutyric acid uptake and total neuronal numbers after staining showed smaller decrease. We demonstrated that HNM produced modest dopaminergic neurotoxicity in neuron-enriched cultures; in contrast, much greater neurotoxicity was observed in the presence of microglia. HNM-induced microglial activation was shown by morphological changes and production of proinflammatory and neurotoxic factors. These results suggest that HNM, once released from damaged dopaminergic neurons, can be an potent endogenous activator involved in the reactivation of microglia, which may mediate disease progression. Thus, inhibition of reactive microglia can be a useful strategy for PD therapy. PMID:23276965

  1. Sex stratified neuronal cultures to study ischemic cell death pathways.

    PubMed

    Fairbanks, Stacy L; Vest, Rebekah; Verma, Saurabh; Traystman, Richard J; Herson, Paco S

    2013-01-01

    Sex differences in neuronal susceptibility to ischemic injury and neurodegenerative disease have long been observed, but the signaling mechanisms responsible for those differences remain unclear. Primary disassociated embryonic neuronal culture provides a simplified experimental model with which to investigate the neuronal cell signaling involved in cell death as a result of ischemia or disease; however, most neuronal cultures used in research today are mixed sex. Researchers can and do test the effects of sex steroid treatment in mixed sex neuronal cultures in models of neuronal injury and disease, but accumulating evidence suggests that the female brain responds to androgens, estrogens, and progesterone differently than the male brain. Furthermore, neonate male and female rodents respond differently to ischemic injury, with males experiencing greater injury following cerebral ischemia than females. Thus, mixed sex neuronal cultures might obscure and confound the experimental results; important information might be missed. For this reason, the Herson Lab at the University of Colorado School of Medicine routinely prepares sex-stratified primary disassociated embryonic neuronal cultures from both hippocampus and cortex. Embryos are sexed before harvesting of brain tissue and male and female tissue are disassociated separately, plated separately, and maintained separately. Using this method, the Herson Lab has demonstrated a male-specific role for the ion channel TRPM2 in ischemic cell death. In this manuscript, we share and discuss our protocol for sexing embryonic mice and preparing sex-stratified hippocampal primary disassociated neuron cultures. This method can be adapted to prepare sex-stratified cortical cultures and the method for embryo sexing can be used in conjunction with other protocols for any study in which sex is thought to be an important determinant of outcome. PMID:24378980

  2. When and How Do Seizures Kill Neurons, and Is Cell Death Relevant to Epileptogenesis?

    PubMed Central

    Dingledine, Ray; Varvel, Nicholas H.; Dudek, F. Edward

    2015-01-01

    The effect of seizures on neuronal death and the role of seizure-induced neuronal death in acquired epileptogenesis have been debated for decades. Isolated brief seizures probably do not kill neurons; however, severe and repetitive seizures (i.e., status epilepticus) certainly do. Because status epilepticus both kills neurons and also leads to chronic epilepsy, neuronal death has been proposed to be an integral part of acquired epileptogenesis. Several studies, particularly in the immature brain, have suggested that neuronal death is not necessary for acquired epileptogenesis; however, the lack of neuronal death is difficult if not impossible to prove, and more recent studies have challenged this concept. Novel mechanisms of cell death, beyond the traditional concepts of necrosis and apoptosis, include autophagy, phagoptosis, necroptosis, and pyroptosis. The traditional proposal for why neuronal death may be necessary for epileptogenesis is based on the recapitulation of development hypothesis, where a loss of synaptic input from the dying neurons is considered a critical signal to induce axonal sprouting and synaptic-circuit reorganization. We propose a second hypothesis – the neuronal death pathway hypothesis, which states that the biochemical pathways causing programmed neurodegeneration, rather than neuronal death per se, are responsible for or contribute to epileptogenesis. The reprogramming of neuronal death pathways – if true – is proposed to derive from necroptosis or pyroptosis. The proposed new hypothesis may inform on why neuronal death seems closely linked to epileptogenesis, but may not always be. PMID:25012371

  3. 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

  4. Neuronal death in Alzheimer’s disease and therapeutic opportunities

    PubMed Central

    Donev, Rossen; Kolev, Martin; Millet, Bruno; Thome, Johannes

    2009-01-01

    Alzheimer’s disease (AD) is an age-related neurodegenerative disease that affects approximately 24 million people worldwide. A number of different risk factors have been implicated in AD; however, neuritic (amyloid) plaques are considered as one of the defining risk factors and pathological hallmarks of the disease. In the past decade, enormous efforts have been devoted to understand the genetics and molecular pathogenesis leading to neuronal death in AD, which has been transferred into extensive experimental approaches aimed at reversing disease progression. Modern medicine is facing an increasing number of treatments available for vascular and neurodegenerative brain diseases, but no causal or neuroprotective treatment has yet been established. Almost all neurological conditions are characterized by progressive neuronal dysfunction, which, regardless of the pathogenetic mechanism, finally leads to neuronal death. The particular emphasis of this review is on risk factors and mechanisms resulting in neuronal loss in AD and current and prospective opportunities for therapeutic interventions. This review discusses these issues with a view to inspiring the development of new agents that could be useful for the treatment of AD. PMID:19725918

  5. Microglial activation induces neuronal death in Chandipura virus infection

    PubMed Central

    Verma, Abhishek Kumar; Ghosh, Sourish; Pradhan, Sreeparna; Basu, Anirban

    2016-01-01

    Neurotropic viruses induce neurodegeneration either directly by activating host death domains or indirectly through host immune response pathways. Chandipura Virus (CHPV) belonging to family Rhabdoviridae is ranked among the emerging pathogens of the Indian subcontinent. Previously we have reported that CHPV induces neurodegeneration albeit the root cause of this degeneration is still an open question. In this study we explored the role of microglia following CHPV infection. Phenotypic analysis of microglia through lectin and Iba-1 staining indicated cells were in an activated state post CHPV infection in cortical region of the infected mouse brain. Cytokine Bead Array (CBA) analysis revealed comparatively higher cytokine and chemokine levels in the same region. Increased level of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), Nitric Oxide (NO) and Reactive Oxygen species (ROS) in CHPV infected mouse brain indicated a strong inflammatory response to CHPV infection. Hence it was hypothesized through our analyses that this inflammatory response may stimulate the neuronal death following CHPV infection. In order to validate our hypothesis supernatant from CHPV infected microglial culture was used to infect neuronal cell line and primary neurons. This study confirmed the bystander killing of neurons due to activation of microglia post CHPV infection. PMID:26931456

  6. HIP/PAP prevents excitotoxic neuronal death and promotes plasticity

    PubMed Central

    Haldipur, Parthiv; Dupuis, Nina; Degos, Vincent; Moniaux, Nicolas; Chhor, Vibol; Rasika, Sowmyalakshmi; Schwendimann, Leslie; le Charpentier, Tifenn; Rougier, Elodie; Amouyal, Paul; Amouyal, Gilles; Dournaud, Pascal; Bréchot, Christian; El Ghouzzi, Vincent; Faivre, Jamila; Fleiss, Bobbi; Mani, Shyamala; Gressens, Pierre

    2014-01-01

    Objectives Excitotoxicity plays a significant role in the pathogenesis of perinatal brain injuries. Among the consequences of excessive activation of the N-methyl-d-aspartate (NMDA)-type glutamate are oxidative stress caused by free radical release from damaged mitochondria, neuronal death and subsequent loss of connectivity. Drugs that could protect nervous tissue and support regeneration are attractive therapeutic options. The hepatocarcinoma intestine pancreas protein/pancreatitis-associated protein I (HIP/PAP) or Reg3α, which is approved for clinical testing for the protection and regeneration of the liver, is upregulated in the central nervous system following injury or disease. Here, we examined the neuroprotective/neuroregenerative potential of HIP/PAP following excitotoxic brain injury. Methods We studied the expression of HIP/PAP and two of its putative effectors, cAMP-regulated phosphoprotein 19 (ARPP19) and growth-associated protein 43 (GAP-43), in the neonatal brain, and the protective/regenerative properties of HIP/PAP in three paradigms of perinatal excitotoxicity: intracerebral injection of the NMDA agonist ibotenate in newborn pups, a pediatric model of traumatic brain injury, and cultured primary cortical neurons. Results HIP/PAP, ARPP19, and GAP-43 were expressed in the neonatal mouse brain. HIP/PAP prevented the formation of cortical and white matter lesions and reduced neuronal death and glial activation following excitotoxic insults in vivo. In vitro, HIP/PAP promoted neuronal survival, preserved neurite complexity and fasciculation, and protected cell contents from reactive oxygen species (ROS)-induced damage. Interpretation HIP/PAP has strong neuroprotective/neuroregenerative potential following excitotoxic injury to the developing brain, and could represent an interesting therapeutic strategy in perinatal brain injury. PMID:25493266

  7. Axonal Dysfunction Precedes Motor Neuronal Death in Amyotrophic Lateral Sclerosis.

    PubMed

    Iwai, Yuta; Shibuya, Kazumoto; Misawa, Sonoko; Sekiguchi, Yukari; Watanabe, Keisuke; Amino, Hiroshi; Kuwabara, Satoshi

    2016-01-01

    Wide-spread fasciculations are a characteristic feature in amyotrophic lateral sclerosis (ALS), suggesting motor axonal hyperexcitability. Previous excitability studies have shown increased nodal persistent sodium conductances and decreased potassium currents in motor axons of ALS patients, both of the changes inducing hyperexcitability. Altered axonal excitability potentially contributes to motor neuron death in ALS, but the relationship of the extent of motor neuronal death and abnormal excitability has not been fully elucidated. We performed multiple nerve excitability measurements in the median nerve at the wrist of 140 ALS patients and analyzed the relationship of compound muscle action potential (CMAP) amplitude (index of motor neuronal loss) and excitability indices, such as strength-duration time constant, threshold electrotonus, recovery cycle and current-threshold relationships. Compared to age-matched normal controls (n = 44), ALS patients (n = 140) had longer strength-duration time constant (SDTC: a measure of nodal persistent sodium current; p < 0.05), greater threshold changes in depolarizing threshold electrotonus (p < 0.05) and depolarizing current threshold relationship (i.e. less accommodation; (p < 0.05), greater superexcitability (a measure of fast potassium current; p < 0.05) and reduced late subexcitability (a measure of slow potassium current; p < 0.05), suggesting increased persistent sodium currents and decreased potassium currents. The reduced potassium currents were found even in the patient subgroups with normal CMAP (> 5mV). Regression analyses showed that SDTC (R = -0.22) and depolarizing threshold electrotonus (R = -0.22) increased with CMAP decline. These findings suggest that motor nerve hyperexcitability occurs in the early stage of the disease, and precedes motor neuronal loss in ALS. Modulation of altered ion channel function could be a treatment option for ALS. PMID:27383069

  8. Axonal Dysfunction Precedes Motor Neuronal Death in Amyotrophic Lateral Sclerosis

    PubMed Central

    Iwai, Yuta; Shibuya, Kazumoto; Misawa, Sonoko; Sekiguchi, Yukari; Watanabe, Keisuke; Amino, Hiroshi; Kuwabara, Satoshi

    2016-01-01

    Wide-spread fasciculations are a characteristic feature in amyotrophic lateral sclerosis (ALS), suggesting motor axonal hyperexcitability. Previous excitability studies have shown increased nodal persistent sodium conductances and decreased potassium currents in motor axons of ALS patients, both of the changes inducing hyperexcitability. Altered axonal excitability potentially contributes to motor neuron death in ALS, but the relationship of the extent of motor neuronal death and abnormal excitability has not been fully elucidated. We performed multiple nerve excitability measurements in the median nerve at the wrist of 140 ALS patients and analyzed the relationship of compound muscle action potential (CMAP) amplitude (index of motor neuronal loss) and excitability indices, such as strength-duration time constant, threshold electrotonus, recovery cycle and current-threshold relationships. Compared to age-matched normal controls (n = 44), ALS patients (n = 140) had longer strength-duration time constant (SDTC: a measure of nodal persistent sodium current; p < 0.05), greater threshold changes in depolarizing threshold electrotonus (p < 0.05) and depolarizing current threshold relationship (i.e. less accommodation; (p < 0.05), greater superexcitability (a measure of fast potassium current; p < 0.05) and reduced late subexcitability (a measure of slow potassium current; p < 0.05), suggesting increased persistent sodium currents and decreased potassium currents. The reduced potassium currents were found even in the patient subgroups with normal CMAP (> 5mV). Regression analyses showed that SDTC (R = -0.22) and depolarizing threshold electrotonus (R = -0.22) increased with CMAP decline. These findings suggest that motor nerve hyperexcitability occurs in the early stage of the disease, and precedes motor neuronal loss in ALS. Modulation of altered ion channel function could be a treatment option for ALS. PMID:27383069

  9. The p75 Neurotrophin Receptor Can Induce Autophagy and Death of Cerebellar Purkinje Neurons

    PubMed Central

    Florez-McClure, Maria L.; Linseman, Daniel A.; Chu, Charleen T.; Barker, Phil A.; Bouchard, Ron J.; Le, Shoshona S.; Laessig, Tracey A.; Heidenreich, Kim A.

    2007-01-01

    The cellular mechanisms underlying Purkinje neuron death in various neurodegenerative disorders of the cerebellum are poorly understood. Here we investigate an in vitro model of cerebellar neuronal death. We report that cerebellar Purkinje neurons, deprived of trophic factors, die by a form of programmed cell death distinct from the apoptotic death of neighboring granule neurons. Purkinje neuron death was characterized by excessive autophagic–lysosomal vacuolation. Autophagy and death of Purkinje neurons were inhibited by nerve growth factor (NGF) and were activated by NGF-neutralizing antibodies. Although treatment with antisense oligonucleotides to the p75 neurotrophin receptor (p75ntr) decreased basal survival of cultured cerebellar neurons, p75ntr-antisense decreased autophagy and completely inhibited death of Purkinje neurons induced by trophic factor withdrawal. Moreover, adenoviral expression of a p75ntr mutant lacking the ligand-binding domain induced vacuolation and death of Purkinje neurons. These results suggest that p75ntr is required for Purkinje neuron survival in the presence of trophic support; however, during trophic factor withdrawal, p75ntr contributes to Purkinje neuron autophagy and death. The autophagic morphology resembles that found in neurodegenerative disorders, suggesting a potential role for this pathway in neurological disease. PMID:15140920

  10. Humanin Derivatives Inhibit Necrotic Cell Death in Neurons.

    PubMed

    Cohen, Aviv; Lerner-Yardeni, Jenny; Meridor, David; Kasher, Roni; Nathan, Ilana; Parola, Abraham H

    2015-01-01

    Humanin and its derivatives are peptides known for their protective antiapoptotic effects against Alzheimer's disease. Herein, we identify a novel function of the humanin-derivative AGA(C8R)-HNG17 (namely, protection against cellular necrosis). Necrosis is one of the main modes of cell death, which was until recently considered an unmoderated process. However, recent findings suggest the opposite. We have found that AGA(C8R)-HNG17 confers protection against necrosis in the neuronal cell lines PC-12 and NSC-34, where necrosis is induced in a glucose-free medium by either chemohypoxia or by a shift from apoptosis to necrosis. Our studies in traumatic brain injury models in mice, where necrosis is the main mode of neuronal cell death, have shown that AGA(C8R)-HNG17 has a protective effect. This result is demonstrated by a decrease in a neuronal severity score and by a reduction in brain edema, as measured by magnetic resonance imaging (MRI). An insight into the peptide's antinecrotic mechanism was attained through measurements of cellular ATP levels in PC-12 cells under necrotic conditions, showing that the peptide mitigates a necrosis-associated decrease in ATP levels. Further, we demonstrate the peptide's direct enhancement of the activity of ATP synthase activity, isolated from rat-liver mitochondria, suggesting that AGA(C8R)-HNG17 targets the mitochondria and regulates cellular ATP levels. Thus, AGA(C8R)-HNG17 has potential use for the development of drug therapies for necrosis-related diseases, for example, traumatic brain injury, stroke, myocardial infarction, and other conditions for which no efficient drug-based treatment is currently available. Finally, this study provides new insight into the mechanisms underlying the antinecrotic mode of action of AGA(C8R)-HNG17. PMID:26062019

  11. Humanin Derivatives Inhibit Necrotic Cell Death in Neurons

    PubMed Central

    Cohen, Aviv; Lerner-Yardeni, Jenny; Meridor, David; Kasher, Roni; Nathan, Ilana; Parola, Abraham H

    2015-01-01

    Humanin and its derivatives are peptides known for their protective antiapoptotic effects against Alzheimer’s disease. Herein, we identify a novel function of the humanin-derivative AGA(C8R)-HNG17 (namely, protection against cellular necrosis). Necrosis is one of the main modes of cell death, which was until recently considered an unmoderated process. However, recent findings suggest the opposite. We have found that AGA(C8R)-HNG17 confers protection against necrosis in the neuronal cell lines PC-12 and NSC-34, where necrosis is induced in a glucose-free medium by either chemohypoxia or by a shift from apoptosis to necrosis. Our studies in traumatic brain injury models in mice, where necrosis is the main mode of neuronal cell death, have shown that AGA(C8R)-HNG17 has a protective effect. This result is demonstrated by a decrease in a neuronal severity score and by a reduction in brain edema, as measured by magnetic resonance imaging (MRI). An insight into the peptide’s antinecrotic mechanism was attained through measurements of cellular ATP levels in PC-12 cells under necrotic conditions, showing that the peptide mitigates a necrosis-associated decrease in ATP levels. Further, we demonstrate the peptide’s direct enhancement of the activity of ATP synthase activity, isolated from rat-liver mitochondria, suggesting that AGA(C8R)-HNG17 targets the mitochondria and regulates cellular ATP levels. Thus, AGA(C8R)-HNG17 has potential use for the development of drug therapies for necrosis-related diseases, for example, traumatic brain injury, stroke, myocardial infarction, and other conditions for which no efficient drug-based treatment is currently available. Finally, this study provides new insight into the mechanisms underlying the antinecrotic mode of action of AGA(C8R)-HNG17. PMID:26062019

  12. Increase of p25 associated with cortical neuronal death induced by hypoxia.

    PubMed

    Huang, Tianwen; Fang, Lijun; Lin, Zhiying; Huang, En; Ye, Qinyong

    2016-09-01

    The mechanisms of neuronal damage in hypoxic cerebral cortex are complicated. Recent studies indicated that deregulation of Cdk5 was involved in neuronal death induced by hypoxia (1% O2). However, the pathological effect of Cdk5 is not fully elucidated. Therefore, in order to decipher the effect of Cdk5 on cellular death in hypoxic condition, the Cdk5 and its activator p35/p25 were investigated in cortical neurons at 10 DIV (Days In Vitro). Upon exposure to hypoxia, the cortical neurons showed a time-dependent increase of neuronal death compared to normoxia-treated control neurons. In correlation to the increase of neuronal death under hypoxia, the level of p25, a truncated form of p35, also increased in a time-dependent manner. Importantly, inhibition of Cdk5 kinase activity by roscovitine protected neurons from death under hypoxic stress. In contrast, ectopic upregulation of Cdk5 kinase activity in neurons expressing p25 led to an increase of neuronal death in comparison to control neurons expressing GFP. It suggests that ectopic increase of Cdk5 kinase activity through conversion of p35 to p25 is involved in the process of neuronal death induced by hypoxia. PMID:27402274

  13. BAX is required for neuronal death after trophic factor deprivation and during development.

    PubMed

    Deckwerth, T L; Elliott, J L; Knudson, C M; Johnson, E M; Snider, W D; Korsmeyer, S J

    1996-09-01

    Members of the BCL2-related family of proteins either promote or repress programmed cell death. BAX, a death-promoting member, heterodimerizes with multiple death-repressing molecules, suggesting that it could prove critical to cell death. We tested whether Bax is required for neuronal death by trophic factor deprivation and during development. Neonatal sympathetic neurons and facial motor neurons from Bax-deficient mice survived nerve growth factor deprivation and disconnection from their targets by axotomy, respectively. These salvaged neurons displayed remarkable soma atrophy and reduced elaboration of neurities; yet they responded to readdition of trophic factor with soma hypertrophy and enhanced neurite outgrowth. Bax-deficient superior cervical ganglia and facial nuclei possessed increased numbers of neurons. Our observations demonstrate that trophic factor deprivation-induced death of sympathetic and motor neurons depends on Bax. PMID:8816704

  14. Metabotropic glutamate receptor regulation of neuronal cell death.

    PubMed

    Spillson, Alison Berent; Russell, James W

    2003-11-01

    The metabotropic glutamate receptors (mGluRs) are a family of glutamate-sensitive receptors that regulate neuronal function separately from the ionotropic glutamate receptors. By coupling to guanosine nucleotide-binding proteins (G proteins), mGluRs are able to regulate neuronal injury and survival, likely through a series of downstream protein kinase and cysteine protease signaling pathways that affect mitochondrial regulated programmed cell death (PCD). The physiological relevance of this system is supported by evidence that mGluRs are associated with cell survival in several central nervous system neurodegenerative diseases. Evidence is presented that mGluRs are also able to prevent PCD in the peripheral nervous system, and that this may provide a novel mechanism for treatment of diabetic neuropathy. In dorsal root ganglion (DRG) neurons, a high glucose load increases generation of reactive oxygen species (ROS), destabilizes the inner mitochondrial membrane potential (Deltapsi(M)), induces cytochrome c release from the mitochondrial intermembrane space, and induces downstream activation of caspases. In high-glucose conditions, the group II metabotropic glutamate agonist N-acetylaspartylglutamate (NAAG) blocks caspase activation and is completely reversed by the mGluR3 antagonist (S)-alpha-ethylglutamic acid (EGLU). Furthermore, the direct mGluR3 agonist (2R,4R)-4-aminopyrrolidine-2, 4-dicarboxylate (APDC) prevents induction of ROS. Together these findings are consistent with an emerging concept that mGluRs may protect against cellular injury by regulating oxidative stress in the neuron. More complete understanding of the complex PCD regulatory pathways mediated by mGluRs will provide new therapeutic approaches for the treatment of a wide variety of neurodegenerative diseases. PMID:14597332

  15. Neuronal gap junction coupling is regulated by glutamate and plays critical role in cell death during neuronal injury.

    PubMed

    Wang, Yongfu; Song, Ji-Hoon; Denisova, Janna V; Park, Won-Mee; Fontes, Joseph D; Belousov, Andrei B

    2012-01-11

    In the mammalian CNS, excessive release of glutamate and overactivation of glutamate receptors are responsible for the secondary (delayed) neuronal death following neuronal injury, including ischemia, traumatic brain injury (TBI), and epilepsy. The coupling of neurons by gap junctions (electrical synapses) increases during neuronal injury. We report here that the ischemic increase in neuronal gap junction coupling is regulated by glutamate via group II metabotropic glutamate receptors (mGluRs). Specifically, using electrotonic coupling, Western blots, and siRNA in the mouse somatosensory cortex in vivo and in vitro, we demonstrate that activation of group II mGluRs increases background levels of neuronal gap junction coupling and expression of connexin 36 (Cx36) (neuronal gap junction protein), and inactivation of group II mGluRs prevents the ischemia-mediated increases in the coupling and Cx36 expression. We also show that the regulation is via cAMP/PKA (cAMP-dependent protein kinase)-dependent signaling and posttranscriptional control of Cx36 expression and that other glutamate receptors are not involved in these regulatory mechanisms. Furthermore, using the analysis of neuronal death, we show that inactivation of group II mGluRs or genetic elimination of Cx36 both dramatically reduce ischemia-mediated neuronal death in vitro and in vivo. Similar results are obtained using in vitro models of TBI and epilepsy. Our results indicate that neuronal gap junction coupling is a critical component of glutamate-dependent neuronal death. They also suggest that causal link among group II mGluR function, neuronal gap junction coupling, and neuronal death has a universal character and operates in different types of neuronal injuries. PMID:22238107

  16. Acute myocardial infarction and sudden death in Sioux Indians.

    PubMed Central

    Hrabovsky, S L; Welty, T K; Coulehan, J L

    1989-01-01

    While some Indian tribes have low rates of acute myocardial infarction, Northern Plains Indians, including the Sioux, have rates of morbidity and mortality from acute myocardial infarction higher than those reported for the United States population in general. In a review of diagnosed cases of acute myocardial infarction over a 3-year period in 2 hospitals serving predominantly Sioux Indians, 8% of cases were found misclassified, and 22% failed to meet rigorous diagnostic criteria, although the patients did indeed have ischemic heart disease. Patients had high frequencies of complications and risk factors and a fatality rate of 16% within a month of admission. Sudden deaths likely due to ischemic heart disease but in persons not diagnosed as having acute myocardial infarction by chart review occurred 3 times more frequently than deaths occurring within a month of clinical diagnosis. PMID:2735047

  17. Decreased cysteine uptake by EAAC1 gene deletion exacerbates neuronal oxidative stress and neuronal death after traumatic brain injury.

    PubMed

    Choi, Bo Young; Kim, In Yeol; Kim, Jin Hee; Lee, Bo Eun; Lee, Song Hee; Kho, A Ra; Jung, Hee Jae; Sohn, Min; Song, Hong Ki; Suh, Sang Won

    2016-07-01

    Excitatory amino acid carrier type 1 (EAAC1), a high-affinity glutamate transporter, can expend energy to move glutamate into neurons. However, under normal physiological conditions, EAAC1 does not have a great effect on glutamate clearance but rather participates in the neuronal uptake of cysteine. This process is critical to maintaining neuronal antioxidant function by providing cysteine for glutathione synthesis. Previous study showed that mice lacking EAAC1 show increased neuronal oxidative stress following transient cerebral ischemia. In the present study, we sought to characterize the role of EAAC1 in neuronal resistance after traumatic brain injury (TBI). Young adult C57BL/6 wild-type or EAAC1 (-/-) mice were subjected to a controlled cortical impact model for TBI. Neuronal death after TBI showed more than double the number of degenerating neurons in the hippocampus in EAAC1 (-/-) mice compared with wild-type mice. Superoxide production, zinc translocation and microglia activation similarly showed a marked increase in the EAAC1 (-/-) mice. Pretreatment with N-acetyl cysteine (NAC) reduced TBI-induced neuronal death, superoxide production and zinc translocation. These findings indicate that cysteine uptake by EAAC1 is important for neuronal antioxidant function and survival following TBI. This study also suggests that administration of NAC has therapeutic potential in preventing TBI-induced neuronal death. PMID:27040821

  18. 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

  19. Excitotoxic neuronal death in the immature brain is an apoptosis-necrosis morphological continuum.

    PubMed

    Portera-Cailliau, C; Price, D L; Martin, L J

    1997-02-01

    Glutamate-induced excitotoxicity is a clinically relevant degenerative process that causes selective neuronal death by mechanisms that remain unclear. Cell death is usually classified as apoptotic or necrotic based on biochemical and morphological criteria. Excitotoxic lesions in the adult rat striatum result in neuronal death associated with apoptotic DNA laddering despite a necrotic appearance of neurons ultrastructurally. This suggests that apoptosis and necrosis may not be mutually exclusive modes of cell death. Here, we characterized normal developmental cell death in the newborn rat brain with respect to DNA fragmentation patterns and ultrastructural morphology to establish a standard for apoptosis in the nervous system, and we concluded that it is essentially indistinguishable from apoptosis described in other tissues. We then investigated whether brain maturity could influence the morphology of neuronal death in vivo in the excitotoxically lesioned newborn rat forebrain. Kainic acid induced DNA laddering and death of neurons exhibiting a variety of morphologies, ranging from necrosis to apoptosis. In neurons that were dying by apoptosis, morphologic changes were characterized by a highly ordered sequence of organelle abnormalities, with swelling of endoplasmic reticulum and Golgi vesiculation preceding most nuclear changes and mitochondrial disruption. We concluded that brain maturity influences the morphologic phenotype of neurodegeneration and that excitotoxic neuronal death in the immature brain is not a uniform event but, rather, a continuum of apoptotic, necrotic, and overlapping morphologies. This excitotoxic paradigm might prove useful for analyzing the mechanisms that govern cell death under physiological and pathological conditions. PMID:9120055

  20. Thrombo-hemorrhagic deaths in acute promyelocytic leukemia.

    PubMed

    Breccia, Massimo; Lo Coco, Francesco

    2014-05-01

    Acute promyelocytic leukemia (APL) has become the most curable form of acute myeloid leukemia after the advent of all-trans retinoic acid (ATRA). However, early deaths (ED) mostly due to the disease-associated coagulopathy remain the major cause of treatment failure. In particular, hemorrhagic events account for 40-65% of ED and several prognostic factors have been identified for such hemorrhagic deaths, including poor performance status, high white blood cell (WBC) count and coagulopathy. Occurrence of thrombosis during treatment with ATRA may be associated with differentiation syndrome (DS) or represent an isolated event. Some prognostic factors have been reported to be associated with thrombosis, including increased WBC or aberrant immunophenotype of leukemic promyelocytes. Aim of this review is to report the incidence, severity, possible pathogenesis and clinical manifestations of thrombo-haemorrhagic deaths in APL. PMID:24862130

  1. 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

  2. Child homicide or natural death? A case report of unexpected death of unusual asymptomatic acute laryngotracheobronchitis.

    PubMed

    Zhuo, Luo; Liu, Liang; Ren, Liang; Liu, Qian

    2016-07-01

    Cases involving the unexpected deaths of children are always a concern for the police and medical examiners alike. In particular, unexpected deaths due to asphyxia without obvious injuries sometimes make decisions regarding the manner of death more difficult. In the present case, a 2-year-old boy was found dead at home, and his mother was initially believed to have killed him. A complete autopsy and forensic investigation were performed, and no injuries were found on the body; however, marked laryngeal edema was observed. Histology showed extensive inflammatory infiltration of the mucosa and submucosa of the larynx, trachea, and bronchi. The cause of death was given as respiratory failure due to acute laryngotracheobronchitis; thus, the manner of death was natural. This case helps to remind the forensic community to keep an open mind and consider a broad differential diagnosis when approaching a case rather than jumping to a conclusion based solely on a preliminary investigation. PMID:26101441

  3. Evidence of early involvement of apoptosis inducing factor-induced neuronal death in Alzheimer brain

    PubMed Central

    Lee, Ji-Hye; Cheon, Young-Hee; Woo, Ran-Sook; Song, Dae-Yong; Moon, Cheil

    2012-01-01

    Apoptosis inducing factor (AIF) has been proposed to act as a putative reactive oxygen species scavenger in mitochondria. When apoptotic cell death is triggered, AIF translocates to the nucleus, where it leads to nuclear chromatin condensation and large-scale DNA fragmentation which result in caspase-independent neuronal death. We performed this study to investigate the possibility that, in addition to caspase-dependent neuronal death, AIF induced neuronal death could be a cause of neuronal death in Alzheimer's disease (AD). We have found that AIF immunoreactivity was increased in the hippocampal pyramidal neurons in the Alzheimer brains compared to those of healthy, age-matched control brains. Nuclear AIF immunoreactivity was detected in the apoptotic pyramidal CA1 neurons at the early stage of AD and CA2 at the advanced stage. Nuclear AIF positive neurons were also observed in the amygdala and cholinergic neurons of the basal forebrain (BFCN) from the early stages of AD. The results of this study imply that AIF-induced apoptosis may contribute to neuronal death within the hippocampus, amygdala, and BFCN in early of AD. PMID:22536549

  4. JNK pathway activation is able to synchronize neuronal death and glial phagocytosis in Drosophila

    PubMed Central

    Shklover, J; Mishnaevski, K; Levy-Adam, F; Kurant, E

    2015-01-01

    Glial phagocytosis of superfluous neurons and damaged or aberrant neuronal material is crucial for normal development and maintenance of the CNS. However, the molecular mechanisms underlying the relationship between neuronal death and glial phagocytosis are poorly understood. We describe a novel mechanism that is able to synchronize neuronal cell death and glial phagocytosis of dying neurons in the Drosophila embryonic CNS. This mechanism involves c-Jun N-terminal kinase (JNK) signaling, which is required for developmental apoptosis of specific neurons during embryogenesis. We demonstrate that the dJNK pathway gain-of-function in neurons leads to dJNK signaling in glia, which results in upregulation of glial phagocytosis. Importantly, this promotion of phagocytosis is not mediated by upregulation of the glial phagocytic receptors SIMU and DRPR, but by increasing glial capacity to degrade apoptotic particles inside phagosomes. The proposed mechanism may be important for removal of damaged neurons in the developing and mature CNS. PMID:25695602

  5. Transnitrosylation of XIAP Regulates Caspase-Dependent Neuronal Cell Death

    PubMed Central

    Nakamura, Tomohiro; Wang, Lei; Wong, Catherine C. L.; Scott, Fiona L.; Eckelman, Brendan P.; Han, Xuemei; Tzitzilonis, Christos; Meng, Fanjun; Gu, Zezong; Holland, Emily A.; Clemente, Arjay T.; Okamoto, Shu-ichi; Salvesen, Guy S.; Riek, Roland; Yates, John R.; Lipton, Stuart A.

    2010-01-01

    SUMMARY X-linked inhibitor of apoptosis (XIAP) is a potent antagonist of caspase apoptotic activity. XIAP also functions as an E3 ubiquitin ligase, targeting caspases for degradation. However, molecular pathways controlling XIAP activities remain unclear. Here we report that nitric oxide (NO) reacts with XIAP by S-nitrosylating its RING domain (forming SNO-XIAP), thereby inhibiting E3 ligase and antiapoptotic activity. NO-mediated neurotoxicity and caspase activation have been linked to several neurodegenerative disorders, including Alzheimer’s, Parkinson’s, and Huntington’s diseases. We find significant SNO-XIAP formation in brains of patients with these diseases, implicating this reaction in the etiology of neuronal damage. Conversely, S-nitrosylation of caspases is known to inhibit apoptotic activity. Unexpectedly, we find that SNO-caspase transnitrosylates (transfers its NO group) to XIAP, forming SNO-XIAP, and thus promotes cell injury and death. These findings provide unique insights into the regulation of caspase activation in neurodegenerative disorders mediated, at least in part, by nitrosative stress. PMID:20670888

  6. Secretory phospholipase A2-mediated neuronal cell death involves glutamate ionotropic receptors.

    PubMed

    Kolko, Miriam; de Turco, Elena B; Diemer, Nils Henrik; Bazan, Nicolas G

    2002-10-28

    To define the significance of glutamate ionotropic receptors in sPLA -mediated neuronal cell death we used the NMDA receptor antagonist MK-801 and the AMPA receptor antagonist PNQX. In primary neuronal cell cultures both MK-801 and PNQX inhibited sPLA - and glutamate-induced neuronal death. [ H]Arachidonic acid release induced by both sPLA and glutamate was partially blocked by MK-801, indicating that the glutamate-NMDA-cPLA pathway contributes to sPLA -induced arachidonic acid release. Systemic administration of MK-801 to rats that had sPLA injected into the right striatum significantly decreased neuronal cell death. We conclude that glutamatergic synaptic activity modulates sPLA -induced neuronal cell death. PMID:12395100

  7. 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

  8. 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

  9. Early immature neuronal death is partially involved in memory impairment induced by cerebral ischemia.

    PubMed

    Yi, Jee Hyun; Cho, So Yeon; Jeon, Se Jin; Jung, Ji Wook; Park, Man Seok; Kim, Dong Hyun; Ryu, Jong Hoon

    2016-07-15

    Memory impairment is a common after an ischemic stroke. While delayed neuronal death in the CA1 region is usually linked to cerebral ischemia-induced memory impairment, the role of early immature neuronal death within the DG region in the memory state of an ischemic stroke model has rarely been studied. Here, we show a partial role of immature neuronal death in memory impairment in a global ischemia model. We found early immature neuronal death, which was determined by DCX and NeuN-double-staining. Injection of z-DEVD-fmk, a caspase-3 inhibitor, into the DG region rescued cells from immature neuronal death in the DG region without affecting delayed neuronal death in the CA1 region of an ischemic brain. Moreover, z-DEVD-fmk treatment partially rescued ischemia-induced spatial memory impairment. We also found that ischemia-induced LTP impairment in the perforant pathway was restored by z-DEVD-fmk treatment. These results suggest that early immature neuronal death is partially involved in ischemia-induced spatial memory impairment. PMID:27085588

  10. Semaphorin 3A is a retrograde cell death signal in developing sympathetic neurons.

    PubMed

    Wehner, Amanda B; Abdesselem, Houari; Dickendesher, Travis L; Imai, Fumiyasu; Yoshida, Yutaka; Giger, Roman J; Pierchala, Brian A

    2016-05-01

    During development of the peripheral nervous system, excess neurons are generated, most of which will be lost by programmed cell death due to a limited supply of neurotrophic factors from their targets. Other environmental factors, such as 'competition factors' produced by neurons themselves, and axon guidance molecules have also been implicated in developmental cell death. Semaphorin 3A (Sema3A), in addition to its function as a chemorepulsive guidance cue, can also induce death of sensory neurons in vitro The extent to which Sema3A regulates developmental cell death in vivo, however, is debated. We show that in compartmentalized cultures of rat sympathetic neurons, a Sema3A-initiated apoptosis signal is retrogradely transported from axon terminals to cell bodies to induce cell death. Sema3A-mediated apoptosis utilizes the extrinsic pathway and requires both neuropilin 1 and plexin A3. Sema3A is not retrogradely transported in older, survival factor-independent sympathetic neurons, and is much less effective at inducing apoptosis in these neurons. Importantly, deletion of either neuropilin 1 or plexin A3 significantly reduces developmental cell death in the superior cervical ganglia. Taken together, a Sema3A-initiated apoptotic signaling complex regulates the apoptosis of sympathetic neurons during the period of naturally occurring cell death. PMID:27143756

  11. RARβ regulates neuronal cell death and differentiation in the avian ciliary ganglion

    PubMed Central

    Boerries, Melanie; Busch, Hauke

    2015-01-01

    ABSTRACT Programmed cell death during chicken ciliary ganglion (CG) development is mostly discussed as an extrinsically regulated process, guided either by the establishment of a functional balance between preganglionic and postganglionic activity or the availability of target‐derived neurotrophic factors. We found that the expression of the gene coding for the nuclear retinoic acid receptor β (RARB) is transiently upregulated prior to and during the execution phase of cell death in the CG. Using retroviral vectors, the expression of RARB was knocked down during embryonic development in ovo. The knockdown led to a significant increase in CG neuron number after the cell death phase. BrdU injections and active caspase‐3 staining revealed that this increase in neuron number was due to an inhibition of apoptosis during the normal cell death phase. Furthermore, apoptotic neuron numbers were significantly increased at a stage when cell death is normally completed. While the cholinergic phenotype of the neurons remained unchanged after RARB knockdown, the expression of the proneural gene Cash1 was increased, but somatostatin‐like immunoreactivity, a hallmark of the mature choroid neuron population, was decreased. Taken together, these results point toward a delay in neuronal differentiation as well as cell death. The availability of nuclear retinoic acid receptor β (RARβ) and RARβ‐induced transcription of genes could therefore be a new intrinsic cue for the maturation of CG neurons and their predisposition to undergo cell death. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 75: 1204–1218, 2015 PMID:25663354

  12. Respiratory function after selective respiratory motor neuron death from intrapleural CTB–saporin injections

    PubMed Central

    Nichols, Nicole L.; Vinit, Stéphane; Bauernschmidt, Lorene; Mitchell, Gordon S.

    2015-01-01

    Amyotrophic lateral sclerosis (ALS) causes progressive motor neuron degeneration, paralysis and death by ventilatory failure. In rodent ALS models: 1) breathing capacity is preserved until late in disease progression despite major respiratory motor neuron death, suggesting unknown forms of compensatory respiratory plasticity; and 2) spinal microglia become activated in association with motor neuron cell death. Here, we report a novel experimental model to study the impact of respiratory motor neuron death on compensatory responses without many complications attendant to spontaneous motor neuron disease. In specific, we used intrapleural injections of cholera toxin B fragment conjugated to saporin (CTB–SAP) to selectively kill motor neurons with access to the pleural space. Motor neuron survival, CD11b labeling (microglia), ventilatory capacity and phrenic motor output were assessed in rats 3–28 days after intrapleural injections of: 1) CTB–SAP (25 and 50 μg), or 2) unconjugated CTB and SAP (i.e. control; (CTB + SAP). CTB–SAP elicited dose-dependent phrenic and intercostal motor neuron death; 7 days post-25 μg CTB–SAP, motor neuron survival approximated that in end-stage ALS rats (phrenic: 36 ± 7%; intercostal: 56 ± 10% of controls; n = 9; p < 0.05). CTB–SAP caused minimal cell death in other brainstem or spinal cord regions. CTB–SAP: 1) increased CD11b fractional area in the phrenic motor nucleus, indicating microglial activation; 2) decreased breathing during maximal chemoreceptor stimulation; and 3) diminished phrenic motor output in anesthetized rats (7 days post-25 μg, CTB–SAP: 0.3 ± 0.07 V; CTB + SAP: 1.5 ± 0.3; n = 9; p < 0.05). Intrapleural CTB–SAP represents a novel, inducible model of respiratory motor neuron death and provides an opportunity to study compensation for respiratory motor neuron loss. PMID:25476493

  13. Motor neuron death in ALS – programmed by astrocytes?

    PubMed Central

    Pirooznia, Sheila K.; Dawson, Valina L.; Dawson, Ted M.

    2014-01-01

    Motor neurons in ALS die via cell-autonomous and non-cell autonomous mechanisms. Using adult human astrocytes and motor neurons, Re et al (2014) discover that familial and sporadic ALS derived human adult astrocytes secrete neurotoxic factors that selectively kill motor neurons through necroptosis, suggesting a new therapeutic avenue. PMID:24607221

  14. Neuronal Cell Death Induced by Mechanical Percussion Trauma in Cultured Neurons is not Preceded by Alterations in Glucose, Lactate and Glutamine Metabolism.

    PubMed

    Jayakumar, A R; Bak, L K; Rama Rao, K V; Waagepetersen, H S; Schousboe, A; Norenberg, M D

    2016-02-01

    Traumatic brain injury (TBI) is a devastating neurological disorder that usually presents in acute and chronic forms. Brain edema and associated increased intracranial pressure in the early phase following TBI are major consequences of acute trauma. On the other hand, neuronal injury, leading to neurobehavioral and cognitive impairments, that usually develop months to years after single or repetitive episodes of head trauma, are major consequences of chronic TBI. The molecular mechanisms responsible for TBI-induced injury, however, are unclear. Recent studies have suggested that early mitochondrial dysfunction and subsequent energy failure play a role in the pathogenesis of TBI. We therefore examined whether oxidative metabolism of (13)C-labeled glucose, lactate or glutamine is altered early following in vitro mechanical percussion-induced trauma (5 atm) to neurons (4-24 h), and whether such events contribute to the development of neuronal injury. Cell viability was assayed using the release of the cytoplasmic enzyme lactate dehydrogenase (LDH), together with fluorescence-based cell staining (calcein and ethidium homodimer-1 for live and dead cells, respectively). Trauma had no effect on the LDH release in neurons from 1 to 18 h. However, a significant increase in LDH release was detected at 24 h after trauma. Similar findings were identified when traumatized neurons were stained with fluorescent markers. Additionally (13)C-labeling of glutamate showed a small, but statistically significant decrease at 14 h after trauma. However, trauma had no effect on the cycling ratio of the TCA cycle at any time-period examined. These findings indicate that trauma does not cause a disturbance in oxidative metabolism of any of the substrates used for neurons. Accordingly, such metabolic disturbance does not appear to contribute to the neuronal death in the early stages following trauma. PMID:26729365

  15. [Acute liver failure after ingestion of death cap mushrooms].

    PubMed

    Zuliani, Anna-Maria; Kabar, Iyad; Mitchell, Todd; Heinzow, Hauke Sebastian

    2016-07-01

    Amatoxins, which are mainly found in Amanita phalloides, Amanita virosa, and Galerina autumnalis, are responsible for the majority of fatal intoxication with green death cap. The intoxication is associated with acute liver failure, which explains the poor prognosis. Acute liver injury is generally preceeded by a gastrointestinal phase with nausea, vomiting and diarrhea. In the course, pre-renal kidney failure due to the associated fluid deficit and fulminant liver failure may occur. General guidelines for the treatment of amatoxin poisoning are yet not available. We report on three patients who suffered from amatoxin mushroom poisoning after ingestion of green death cap mushrooms. Based on the pathophysiology of amatoxin poisoning, we discuss a potential therapeutic approach. PMID:27359312

  16. Protein carbonylation, protein aggregation and neuronal cell death in a murine model of multiple sclerosis

    NASA Astrophysics Data System (ADS)

    Dasgupta, Anushka

    Many studies have suggested that oxidative stress plays an important role in the pathophysiology of both multiple sclerosis (MS) and its animal model experimental autoimmune encephalomyelitis (EAE). Yet, the mechanism by which oxidative stress leads to tissue damage in these disorders is unclear. Recent work from our laboratory has revealed that protein carbonylation, a major oxidative modification caused by severe and/or chronic oxidative stress conditions, is elevated in MS and EAE. Furthermore, protein carbonylation has been shown to alter protein structure leading to misfolding/aggregation. These findings prompted me to hypothesize that carbonylated proteins, formed as a consequence of oxidative stress and/or decreased proteasomal activity, promote protein aggregation to mediate neuronal apoptosis in vitro and in EAE. To test this novel hypothesis, I first characterized protein carbonylation, protein aggregation and apoptosis along the spinal cord during the course of myelin-oligodendrocyte glycoprotein (MOG)35-55 peptide-induced EAE in C57BL/6 mice [Chapter 2]. The results show that carbonylated proteins accumulate throughout the course of the disease, albeit by different mechanisms: increased oxidative stress in acute EAE and decreased proteasomal activity in chronic EAE. I discovered not only that there is a temporal correlation between protein carbonylation and apoptosis but also that carbonyl levels are significantly higher in apoptotic cells. A high number of juxta-nuclear and cytoplasmic protein aggregates containing the majority of the oxidized proteins are also present during the course of EAE, which seems to be due to reduced autophagy. In chapter 3, I show that when gluthathione levels are reduced to those in EAE spinal cord, both neuron-like PC12 (nPC12) cells and primary neuronal cultures accumulate carbonylated proteins and undergo cell death (both by necrosis and apoptosis). Immunocytochemical and biochemical studies also revealed a temporal

  17. 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

  18. Cathepsin B-dependent motor neuron death after nerve injury in the adult mouse

    SciTech Connect

    Sun, Li; Wu, Zhou; Baba, Masashi; Peters, Christoph; Uchiyama, Yasuo; Nakanishi, Hiroshi

    2010-08-27

    Research highlights: {yields} Cathepsin B (CB), a lysosomal cysteine protease, is expressed in neuron and glia. {yields} CB increased in hypogrossal nucleus neurons after nerve injury in adult mice. {yields} CB-deficiency significantly increased the mean survival ratio of injured neurons. {yields} Thus, CB plays a critical role in axotomy-induced neuronal death in adult mice. -- Abstract: There are significant differences in the rate of neuronal death after peripheral nerve injury between species. The rate of neuronal death of motor neurons after nerve injury in the adult rats is very low, whereas that in adult mice is relatively high. However, the understanding of the mechanism underlying axotomy-induced motor neuron death in adult mice is limited. Cathepsin B (CB), a typical cysteine lysosomal protease, has been implicated in three major morphologically distinct pathways of cell death; apoptosis, necrosis and autophagic cell death. The possible involvement of CB in the neuronal death of hypogrossal nucleus (HGN) neurons after nerve injury in adult mice was thus examined. Quantitative analyses showed the mean survival ratio of HGN neurons in CB-deficient (CB-/-) adult mice after nerve injury was significantly greater than that in the wild-type mice. At the same time, proliferation of microglia in the injured side of the HGN of CB-/- adult mice was markedly reduced compared with that in the wild-type mice. On the injured side of the HGN in the wild-type adult mice, both pro- and mature forms of CB markedly increased in accordance with the increase in the membrane-bound form of LC3 (LC3-II), a marker protein of autophagy. Furthermore, the increase in CB preceded an increase in the expression of Noxa, a major executor for axotomy-induced motor neuron death in the adult mouse. Conversely, expression of neither Noxa or LC3-II was observed in the HGN of adult CB-/- mice after nerve injury. These observations strongly suggest that CB plays a critical role in axotomy

  19. Transglutaminase inhibition protects against oxidative stress-induced neuronal death downstream of pathological ERK activation

    PubMed Central

    Basso, Manuela; Berlin, Jill; Li, Xia; Sleiman, Sama F.; Ko, Brendan; Haskew-Layton, Renee; Kim, Eunhee; Antonyak, Marc A.; Cerione, Richard A.; Iismaa, Siiri E.; Willis, Dianna; Cho, Sunghee; Ratan, Rajiv R.

    2012-01-01

    Molecular deletion of transglutaminase 2 (TG2) has been shown to improve function and survival in a host of neurological conditions including stroke, Huntington’s disease, and Parkinson’s disease. However, unifying schemes by which these crosslinking or polyaminating enzymes participate broadly in neuronal death have yet to be presented. Unexpectedly, we found that in addition to TG2, TG1 gene expression level is significantly induced following stroke in vivo or due to oxidative stress in vitro. Forced expression of TG1 or TG2 proteins is sufficient to induce neuronal death in Rattus novergicus cortical neurons in vitro. Accordingly, molecular deletion of TG2 alone is insufficient to protect Mus musculus neurons from oxidative death. By contrast, structurally diverse inhibitors used at concentrations that inhibit TG1 and TG2 simultaneously are neuroprotective. These small molecules inhibit increases in neuronal transamidating activity induced by oxidative stress; they also protect neurons downstream of pathological ERK activation when added well after the onset of the death stimulus. Together, these studies suggest that multiple TG isoforms, not only TG2, participate in oxidative stress-induced cell death signaling; and that isoform non-selective inhibitors of TG will be most efficacious in combating oxidative death in neurological disorders. PMID:22573678

  20. Widespread elimination of naturally occurring neuronal death in Bax-deficient mice.

    PubMed

    White, F A; Keller-Peck, C R; Knudson, C M; Korsmeyer, S J; Snider, W D

    1998-02-15

    The proapoptotic molecule BAX is required for death of sympathetic and motor neurons in the setting of trophic factor deprivation. Furthermore, adult Bax-/- mice have more motor neurons than do their wild-type counterparts. These findings raise the possibility that BAX regulates naturally occurring cell death during development in many neuronal populations. To test this idea, we assessed apoptosis using TUNEL labeling in several well-studied neural systems during embryonic and early postnatal development in Bax-/- mice. Remarkably, naturally occurring cell death is virtually eliminated between embryonic day 11.5 (E11.5) and postnatal day 1 (PN1) in most peripheral ganglia, in motor pools in the spinal cord, and in the trigeminal brainstem nuclear complex. Additionally, reduction, although not elimination, of cell death was noted throughout the developing cerebellum, in some layers of the retina, and in the hippocampus. Saving of cells was verified by axon counts of dorsal and ventral roots, as well as facial and optic nerves that revealed 24-35% increases in axon number. Interestingly, many of the supernumerary axons had very small cross-sectional areas, suggesting that the associated neurons are not normal. We conclude that BAX is a critical mediator of naturally occurring death of peripheral and CNS neurons during embryonic life. However, rescue from naturally occurring cell death does not imply that the neurons will develop normal functional capabilities. PMID:9454852

  1. Early prediction of death in acute hypertensive intracerebral hemorrhage

    PubMed Central

    CHEN, GUOFANG; PING, LEI; ZHOU, SHENGKUI; LIU, WEIWEI; LIU, LEIJING; ZHANG, DONGMEI; LI, ZAILI; TIAN, YONGFANG; CHEN, ZHEN

    2016-01-01

    Hypertensive intracerebral hemorrhage (HICH) has been on the decline. However, mortality at long-term follow up is on the increase. The aim of the present study was to investigate early warning signals of death in patients with acute HICH. The medical records of 128 patients with acute HICH within 6 h of onset were retrospectively analyzed. For these patients, systolic blood pressure (BP) was recorded at different time points (emergency, admission, every 6 h within 24 h and twice daily after 24 h) within 1 week. Computed tomography scanning was performed at emergency and the following 24±3 h to assess the hematoma volume. Neurological impairment was evaluated using the Glasgow Coma Scale and National Institutes of Health Stroke Scale. Outcomes were death, defined as a modified Rankin scale score 6, at 90 days. The results showed that at 90 days, 15 HICH patients succumbed (mortality of 11.7%). Of the 15 patients, 1 patient (6.7%) sucumbed within 24 h and 6 patients (40%) within 1 week. HICH mortality was closely associated with age (P<0.001) but not with gender. A significant association was detected between mortality and high BP taken at 30 min, 45 min and 6 h after admission (P=0.003), albeit not at emergency and admission (P>0.05). Death was also correlated with hematoma volume at 24 h but not with the site. Results from the multivariate binary logistic regression analysis showed that age and hematoma volume were independent risk factors of death of HICH. In conclusion, age and hematoma volume may be important early predictors of death in HICH. Proactive control and management of hematoma may reduce the mortality of HICH. PMID:26889222

  2. 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

  3. 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

  4. 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

  5. Cocaine-induced oxidative stress precedes cell death in human neuronal progenitor cells.

    PubMed

    Poon, H Fai; Abdullah, Laila; Mullan, Myles A; Mullan, Michael J; Crawford, Fiona C

    2007-01-01

    By 2003, an estimated 34 million Americans had used cocaine according to the National Survey on Drug Use & Health. About 5.9 million of those had used in the past 12 months. Chronic cocaine users often develop addiction, dependency and tolerance to the drug. The psychological and physical effects of cocaine are due to the disruption of the limbic system in the central nervous system (CNS). Increased oxidative stress reported in the frontal cortex and the striatum of rats exposed to cocaine suggests that oxidative damage plays a significant role in cocaine-induced disruption of the CNS. Although it is evident that cocaine induces oxidative stress in the CNS, little has been learned about whether such increased oxidative stress is also relevant to apoptosis in cocaine-exposed models. To gain insight into the role of cocaine-induced oxidative stress in apoptosis, we hypothesized that oxidative stress precedes cell death when cocaine is administrated. To test this hypothesis, we have monitored the oxidative stress and apoptotic effects of acute cocaine exposure in human neuronal progenitor cells (HNPC). We found that oxidative stress was significantly increased at 48h after a 30min cocaine exposure compared to control cells, and that this was followed by cell death at 72h. Using the same experimental paradigm we have previously shown that pro-inflammatory genes are up-regulated in cocaine-exposed HNPC at 24h. Therefore, we suggest that the increased oxidative stress (possibly mediated by inflammatory responses) precedes cell death in cocaine-exposed HNPC. This may have implications for the consequences of cocaine abuse in situations where antioxidant capacity is compromised, as in the aging brain. PMID:16956698

  6. Bee Venom Protects against Rotenone-Induced Cell Death in NSC34 Motor Neuron Cells.

    PubMed

    Jung, So Young; Lee, Kang-Woo; Choi, Sun-Mi; Yang, Eun Jin

    2015-09-01

    Rotenone, an inhibitor of mitochondrial complex I of the mitochondrial respiratory chain, is known to elevate mitochondrial reactive oxygen species and induce apoptosis via activation of the caspase-3 pathway. Bee venom (BV) extracted from honey bees has been widely used in oriental medicine and contains melittin, apamin, adolapin, mast cell-degranulating peptide, and phospholipase A₂. In this study, we tested the effects of BV on neuronal cell death by examining rotenone-induced mitochondrial dysfunction. NSC34 motor neuron cells were pretreated with 2.5 μg/mL BV and stimulated with 10 μM rotenone to induce cell toxicity. We assessed cell death by Western blotting using specific antibodies, such as phospho-ERK1/2, phospho-JNK, and cleaved capase-3 and performed an MTT assay for evaluation of cell death and mitochondria staining. Pretreatment with 2.5 μg/mL BV had a neuroprotective effect against 10 μM rotenone-induced cell death in NSC34 motor neuron cells. Pre-treatment with BV significantly enhanced cell viability and ameliorated mitochondrial impairment in rotenone-treated cellular model. Moreover, BV treatment inhibited the activation of JNK signaling and cleaved caspase-3 related to cell death and increased ERK phosphorylation involved in cell survival in rotenone-treated NSC34 motor neuron cells. Taken together, we suggest that BV treatment can be useful for protection of neurons against oxidative stress or neurotoxin-induced cell death. PMID:26402700

  7. Bee Venom Protects against Rotenone-Induced Cell Death in NSC34 Motor Neuron Cells

    PubMed Central

    Jung, So Young; Lee, Kang-Woo; Choi, Sun-Mi; Yang, Eun Jin

    2015-01-01

    Rotenone, an inhibitor of mitochondrial complex I of the mitochondrial respiratory chain, is known to elevate mitochondrial reactive oxygen species and induce apoptosis via activation of the caspase-3 pathway. Bee venom (BV) extracted from honey bees has been widely used in oriental medicine and contains melittin, apamin, adolapin, mast cell-degranulating peptide, and phospholipase A2. In this study, we tested the effects of BV on neuronal cell death by examining rotenone-induced mitochondrial dysfunction. NSC34 motor neuron cells were pretreated with 2.5 μg/mL BV and stimulated with 10 μM rotenone to induce cell toxicity. We assessed cell death by Western blotting using specific antibodies, such as phospho-ERK1/2, phospho-JNK, and cleaved capase-3 and performed an MTT assay for evaluation of cell death and mitochondria staining. Pretreatment with 2.5 μg/mL BV had a neuroprotective effect against 10 μM rotenone-induced cell death in NSC34 motor neuron cells. Pre-treatment with BV significantly enhanced cell viability and ameliorated mitochondrial impairment in rotenone-treated cellular model. Moreover, BV treatment inhibited the activation of JNK signaling and cleaved caspase-3 related to cell death and increased ERK phosphorylation involved in cell survival in rotenone-treated NSC34 motor neuron cells. Taken together, we suggest that BV treatment can be useful for protection of neurons against oxidative stress or neurotoxin-induced cell death. PMID:26402700

  8. DJ-1 protects against cell death following acute cardiac ischemia–reperfusion injury

    PubMed Central

    Dongworth, R K; Mukherjee, U A; Hall, A R; Astin, R; Ong, S-B; Yao, Z; Dyson, A; Szabadkai, G; Davidson, S M; Yellon, D M; Hausenloy, D J

    2014-01-01

    Novel therapeutic targets are required to protect the heart against cell death from acute ischemia–reperfusion injury (IRI). Mutations in the DJ-1 (PARK7) gene in dopaminergic neurons induce mitochondrial dysfunction and a genetic form of Parkinson's disease. Genetic ablation of DJ-1 renders the brain more susceptible to cell death following ischemia–reperfusion in a model of stroke. Although DJ-1 is present in the heart, its role there is currently unclear. We sought to investigate whether mitochondrial DJ-1 may protect the heart against cell death from acute IRI by preventing mitochondrial dysfunction. Overexpression of DJ-1 in HL-1 cardiac cells conferred the following beneficial effects: reduced cell death following simulated IRI (30.4±4.7% with DJ-1 versus 52.9±4.7% in control; n=5, P<0.05); delayed mitochondrial permeability transition pore (MPTP) opening (a critical mediator of cell death) (260±33 s with DJ-1 versus 121±12 s in control; n=6, P<0.05); and induction of mitochondrial elongation (81.3±2.5% with DJ-1 versus 62.0±2.8% in control; n=6 cells, P<0.05). These beneficial effects of DJ-1 were absent in cells expressing the non-functional DJ-1L166P and DJ-1Cys106A mutants. Adult mice devoid of DJ-1 (KO) were found to be more susceptible to cell death from in vivo IRI with larger myocardial infarct sizes (50.9±3.5% DJ-1 KO versus 41.1±2.5% in DJ-1 WT; n≥7, P<0.05) and resistant to cardioprotection by ischemic preconditioning. DJ-1 KO hearts showed increased mitochondrial fragmentation on electron microscopy, although there were no differences in calcium-induced MPTP opening, mitochondrial respiratory function or myocardial ATP levels. We demonstrate that loss of DJ-1 protects the heart from acute IRI cell death by preventing mitochondrial dysfunction. We propose that DJ-1 may represent a novel therapeutic target for cardioprotection. PMID:24577080

  9. Superoxide dismutase protects cultured neurons against death by starvation.

    PubMed Central

    Sáez, J C; Kessler, J A; Bennett, M V; Spray, D C

    1987-01-01

    Brief substrate deprivation resulted in high mortality of superior cervical ganglion neurons in culture, assayed 2 hr later by trypan blue exclusion. Involvement of superoxide anions was indicated by several observations. Survival was increased significantly by prior treatment that induced cells to take up superoxide dismutase. During starvation, neurons reduced nitroblue tetrazolium to form the blue precipitate formazan, and the color change was blocked in neurons preloaded with superoxide dismutase. The incidence of staining was comparable to the mortality. In many cells, brief starvation caused the appearance of fluorescence due to oxidation of 2',7'-dichlorofluorescin to dichlorofluorescein, which indicates that oxidants were generated intracellularly. In some cells fluorescence was transient, as would be caused by membrane breakdown, and these cells were then shown to be dead. Superoxide generation caused by substrate deprivation may contribute importantly to cell damage in a variety of pathological conditions. Images PMID:3472251

  10. Interplay Between Cytosolic Dopamine, Calcium and α-Synuclein Causes Selective Death of Substantia Nigra Neurons

    PubMed Central

    Mosharov, Eugene V.; Larsen, Kristin E.; Kanter, Ellen; Phillips, Kester A.; Wilson, Krystal; Schmitz, Yvonne; Krantz, David E.; Kobayashi, Kazuto; Edwards, Robert H.; Sulzer, David

    2009-01-01

    Summary The basis for selective death of specific neuronal populations in neurodegenerative diseases remains unclear. Parkinson's disease (PD) is a synucleinopathy characterized by a preferential loss of dopaminergic neurons in the substantia nigra (SN), whereas neurons of the ventral tegmental area (VTA) are spared. Using intracellular patch electrochemistry to directly measure cytosolic dopamine (DAcyt) in cultured midbrain neurons, we confirm that elevated DAcyt and its metabolites are neurotoxic and that genetic and pharmacological interventions that decrease DAcyt provide neuroprotection. L-DOPA increased DAcyt in SN neurons to levels 2-3-fold higher than in VTA neurons, a response dependent on dihydropyridine-sensitive Ca2+ channels, resulting in greater susceptibility of SN neurons to L-DOPA-induced neurotoxicity. DAcyt was not altered by α-synuclein deletion, although dopaminergic neurons lacking α-synuclein were resistant to L-DOPA-induced cell death. Thus, an interaction between Ca2+, DAcyt and α-synuclein may underlie the susceptibility of SN neurons in PD, suggesting multiple therapeutic targets. PMID:19409267

  11. Inhibition of telomerase causes vulnerability to endoplasmic reticulum stress-induced neuronal cell death.

    PubMed

    Hosoi, Toru; Nakatsu, Kanako; Shimamoto, Akira; Tahara, Hidetoshi; Ozawa, Koichiro

    2016-08-26

    Endoplasmic reticulum (ER) stress is implicated in several diseases, such as cancer and neurodegenerative diseases. In the present study, we investigated the possible involvement of telomerase in ER stress-induced cell death. ER stress-induced cell death was ameliorated in telomerase reverse transcriptase (TERT) over-expressing MCF7 cells (MCF7-TERT cell). Telomerase specific inhibitor, BIBR1532, reversed the inhibitory effect of TERT on ER stress-induced cell death in MCF7-TERT cells. These findings suggest that BIBR1532 may specifically inhibit telomerase activity, thereby inducing cell death in ER stress-exposed cells. TERT was expressed in the SH-SY5Y neuroblastoma cell line. To analyze the possible involvement of telomerase in ER stress-induced neuronal cell death, we treated SH-SY5Y neuroblastoma cells with BIBR1532 and analyzed ER stress-induced cell death. We found that BIBR1532 significantly enhanced the ER stress-induced neuronal cell death. These findings suggest that inhibition of telomerase activity may enhance vulnerability to neuronal cell death caused by ER stress. PMID:27443785

  12. Mitogen and stress response kinase-1 (MSK1) mediates excitotoxic induced death of hippocampal neurones.

    PubMed

    Hughes, Jane P; Staton, Penny C; Wilkinson, Marc G; Strijbos, Paul J L M; Skaper, Stephen D; Arthur, J Simon C; Reith, Alastair D

    2003-07-01

    Activation of the mitogen-activated protein kinase (MAPK/ERK) signal transduction pathway may mediate excitotoxic neuronal cell death in vitro and during ischemic brain injury in vivo. However, little is known, of the upstream regulation or downstream consequences of ERK activation under these conditions. Magnesium removal has been described to induce hyperexcitability and degeneration in cultured hippocampal neurones. Here, we show that neurotoxicity evoked by Mg2+ removal in primary hippocampal neurones stimulates ERK, but not p38, phosphorylation. Removal of Mg2+ also resulted in induction of the MAPK/ERK substrate mitogen- and stress-response kinase 1 (MSK1) and induced phosphorylation of the MSK1 substrate, the transcription factor cAMP response element binding protein (CREB). Neuronal death and phosphorylation of components in this cascade were inhibited by the Raf inhibitor SB-386023, by the MEK inhibitor U0126, or by the MSK1 inhibitors H89 and Ro318220. Importantly, this form of cell death was inhibited in hippocampal neurones cultured from MSK1-/- mice and inhibitors of Raf or MEK had no additive neuroprotective effect. Together, these data indicate that MSK1 is a physiological kinase for CREB and that this activity is an essential component of activity-dependent neuronal cell death. PMID:12807421

  13. Death due to acute tetrachloroethylene intoxication in a chronic abuser.

    PubMed

    Amadasi, Alberto; Mastroluca, Lavinia; Marasciuolo, Laura; Caligara, Marina; Sironi, Luca; Gentile, Guendalina; Zoja, Riccardo

    2015-05-01

    Volatile substances are used widespread, especially among young people, as a cheap and easily accessible drug. Tetrachloroethylene is one of the solvents exerting effects on the central nervous system with experiences of disinhibition and euphoria. The case presented is that of a 27-year-old female, found dead by her father at home with cotton swabs dipped in the nostrils. She was already known for this type of abuse and previously admitted twice to the hospital for nonfatal acute poisonings. The swabs were still soaked in tetrachloroethylene. Toxicological and histological investigations demonstrated the presence of an overlap between chronic intake of the substance (with high concentrations in sites of accumulation, e.g., the adipose tissue, and contemporary tissue damage, as histologically highlighted) and acute intoxication as final cause of death, with a concentration of 158 mg/L in cardiac blood and 4915 mg/kg in the adipose tissue. No other drugs or medicines were detected in body fluids or tissues, and to our knowledge, this is the highest concentration ever detected in forensic cases. This peculiar case confirms the toxicity of this substance and focuses on the importance of complete histological and toxicological investigations in the distinction between chronic abuse and acute intoxication. PMID:25605280

  14. 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

  15. Redox Regulation of Intracellular Zinc: Molecular Signaling in the Life and Death of Neurons

    PubMed Central

    Aizenman, Elias

    2011-01-01

    Abstract Zn2+ has emerged as a major regulator of neuronal physiology, as well as an important signaling agent in neural injury. The intracellular concentration of this metal is tightly regulated through the actions of Zn2+ transporters and the thiol-rich metal binding protein metallothionein, closely linking the redox status of the cell to cellular availability of Zn2+. Accordingly, oxidative and nitrosative stress during ischemic injury leads to an accumulation of neuronal free Zn2+ and the activation of several downstream cell death processes. While this Zn2+ rise is an established signaling event in neuronal cell death, recent evidence suggests that a transient, sublethal accumulation of free Zn2+ can also play a critical role in neuroprotective pathways activated during ischemic preconditioning. Thus, redox-sensitive proteins, like metallothioneins, may play a critical role in determining neuronal cell fate by regulating the localization and concentration of intracellular free Zn2+. Antioxid. Redox Signal. 15, 2249–2263. PMID:20849376

  16. Glucose Levels in Culture Medium Determine Cell Death Mode in MPP+-treated Dopaminergic Neuronal Cells

    PubMed Central

    Yoon, So-Young

    2015-01-01

    We previously demonstrated that 1-methyl-4-phenylpyridinium (MPP+) causes caspase-independent, non-apoptotic death of dopaminergic (DA) neuronal cells. Here, we specifically examined whether change of glucose concentration in culture medium may play a role for determining cell death modes of DA neurons following MPP+ treatment. By incubating MN9D cells in medium containing varying concentrations of glucose (5~35 mM), we found that cells underwent a distinct cell death as determined by morphological and biochemical criteria. At 5~10 mM glucose concentration (low glucose levels), MPP+ induced typical of the apoptotic dell death accompanied with caspase activation and DNA fragmentation as well as cell shrinkage. In contrast, MN9D cells cultivated in medium containing more than 17.5 mM (high glucose levels) did not demonstrate any of these changes. Subsequently, we observed that MPP+ at low glucose levels but not high glucose levels led to ROS generation and subsequent JNK activation. Therefore, MPP+-induced cell death only at low glucose levels was significantly ameliorated following co-treatment with ROS scavenger, caspase inhibitor or JNK inhibitor. We basically confirmed the quite similar pattern of cell death in primary cultures of DA neurons. Taken together, our results suggest that a biochemically distinct cell death mode is recruited by MPP+ depending on extracellular glucose levels. PMID:26412968

  17. Striatal neuronal death mediated by astrocytes from the Gcdh-/- mouse model of glutaric acidemia type I.

    PubMed

    Olivera-Bravo, Silvia; Ribeiro, César A J; Isasi, Eugenia; Trías, Emiliano; Leipnitz, Guilhian; Díaz-Amarilla, Pablo; Woontner, Michael; Beck, Cheryl; Goodman, Stephen I; Souza, Diogo; Wajner, Moacir; Barbeito, Luis

    2015-08-15

    Glutaric acidemia type I (GA-I) is an inherited neurometabolic childhood disorder caused by defective activity of glutaryl CoA dehydrogenase (GCDH) which disturb lysine (Lys) and tryptophan catabolism leading to neurotoxic accumulation of glutaric acid (GA) and related metabolites. However, it remains unknown whether GA toxicity is due to direct effects on vulnerable neurons or mediated by GA-intoxicated astrocytes that fail to support neuron function and survival. As damaged astrocytes can also contribute to sustain high GA levels, we explored the ability of Gcdh-/- mouse astrocytes to produce GA and induce neuronal death when challenged with Lys. Upon Lys treatment, Gcdh-/- astrocytes synthetized and released GA and 3-hydroxyglutaric acid (3HGA). Lys and GA treatments also increased oxidative stress and proliferation in Gcdh-/- astrocytes, both prevented by antioxidants. Pretreatment with Lys also caused Gcdh-/- astrocytes to induce extensive death of striatal and cortical neurons when compared with milder effect in WT astrocytes. Antioxidants abrogated the neuronal death induced by astrocytes exposed to Lys or GA. In contrast, Lys or GA direct exposure on Gcdh-/- or WT striatal neurons cultured in the absence of astrocytes was not toxic, indicating that neuronal death is mediated by astrocytes. In summary, GCDH-defective astrocytes actively contribute to produce and accumulate GA and 3HGA when Lys catabolism is stressed. In turn, astrocytic GA production induces a neurotoxic phenotype that kills striatal and cortical neurons by an oxidative stress-dependent mechanism. Targeting astrocytes in GA-I may prompt the development of new antioxidant-based therapeutical approaches. PMID:25968119

  18. Adenosine kinase facilitated astrogliosis-induced cortical neuronal death in traumatic brain injury.

    PubMed

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

    2016-06-01

    Adenosine kinase (ADK) plays a pivotal role in regulating brain function by regulating adenosine level, and ADK inhibition protects against neuronal damage in cerebral ischemia and epilepsy; however, the effects of ADK in traumatic brain injury (TBI) have not been investigated. For exploring its effects, we generated a blade-induced rat focal brain injury model. Western blot analysis, immunohistochemistry and immunofluorescent staining suggested that ADK was up-regulated after TBI, and it was temporally and spatially associated with astrogliosis. Terminal deoxynucleotidyl transferase-mediated biotinylated-dUTP nick-end labeling showed that neuronal apoptosis was paralleled with TBI-induced ADK up-regulation and astrogliosis. For further investigating the role of ADK in astrogliosis-induced neuronal death, primary cultured astrocytes and neurons were utilized, lipopolysaccharide (LPS) was employed to mediate astrogliosis, and condition medium (CM) of reactive astrocytes was used to treat neurons. The results showed that astrocytes increased iNOS expression and secreted pro-inflammatory cytokines after LPS treatment, and CM of reactive astrocytes resulted neuronal death. Additionally, ADK knock-down didn't ameliorate LPS-induced astrocyte proliferation, but it protected against neuronal death by reducing iNOS expression, tumor necrosis factor α and interleukin 1β secretion of reactive astrocytes. Taken together, ADK was associated with astrogliosis after TBI, its inhibition in reactive astrocytes ameliorated astrogliosis-induced neuronal death. Our findings extended the current knowledge on the role of ADK in astrogliosis, and also provided new evidence for the TBI treatment. PMID:26983602

  19. 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

  20. Low-Dose Bafilomycin Attenuates Neuronal Cell Death Associated with Autophagy-Lysosome Pathway Dysfunction

    PubMed Central

    Pivtoraiko, Violetta N.; Harrington, Adam J.; Mader, Burton J.; Luker, Austin M.; Caldwell, Guy A.; Caldwell, Kim A.; Roth, Kevin A.; Shacka, John J.

    2010-01-01

    We have shown previously that the plecomacrolide antibiotics bafilomycin A1 and B1 significantly attenuate cerebellar granule neuron death resulting from agents that disrupt lysosome function. To further characterize bafilomycin-mediated cytoprotection, we examined its ability to attenuate the death of naïve and differentiated neuronal SH-SY5Y human neuroblastoma cells from agents that induce lysosome dysfunction in vitro, and from in vivo dopaminergic neuron death in C. elegans. Low-dose bafilomycin significantly attenuated SH-SY5Y cell death resulting from treatment with chloroquine, hydroxychloroquine amodiaquine and staurosporine. Bafilomycin also attenuated the chloroquine-induced reduction in processing of cathepsin D, the principal lysosomal aspartic acid protease, to its mature “active” form. Chloroquine induced autophagic vacuole accumulation and inhibited autophagic flux, effects that were attenuated upon treatment with bafilomycin and were associated with a significant decrease in chloroquine-induced accumulation of detergent-insoluble α-synuclein oligomers. In addition, bafilomycin significantly and dose-dependently attenuated dopaminergic neuron death in C. elegans resulting from in vivo over-expression of human wild-type α-synuclein. Together, our findings suggest that low-dose bafilomycin is cytoprotective in part through its maintenance of the autophagy-lysosome pathway, and underscores its therapeutic potential for treating Parkinson Disease and other neurodegenerative diseases that exhibit disruption of protein degradation pathways and accumulation of toxic protein species. PMID:20534000

  1. Nonapoptotic cell death in acute kidney injury and transplantation.

    PubMed

    Linkermann, Andreas

    2016-01-01

    Acute tubular necrosis causes a loss of renal function, which clinically presents as acute kidney failure (AKI). The biochemical signaling pathways that trigger necrosis have been investigated in detail over the past 5 years. It is now clear that necrosis (regulated necrosis, RN) represents a genetically driven process that contributes to the pathophysiology of AKI. RN pathways such as necroptosis, ferroptosis, parthanatos, and mitochondrial permeability transition-induced regulated necrosis (MPT-RN) may be mechanistically distinct, and the relative contributions to overall organ damage during AKI in living organisms largely remain elusive. In a synchronized manner, some necrotic programs induce the breakdown of tubular segments and multicellular functional units, whereas others are limited to killing single cells in the tubular compartment. Importantly, the means by which a renal cell dies may have implications for the subsequent inflammatory response. In this review, the recent advances in the field of renal cell death in AKI and key enzymes that might serve as novel therapeutic targets will be discussed. As a consequence of the interference with RN, the immunogenicity of dying cells in AKI in renal transplants will be diminished, rendering inhibitors of RN indirect immunosuppressive agents. PMID:26759047

  2. Neuronal life and death: an essential role for the p53 family.

    PubMed

    Miller, F D; Pozniak, C D; Walsh, G S

    2000-10-01

    Recent evidence indicates that the p53 tumor suppressor protein, and its related family member, p73, play an essential role in regulating neuronal apoptosis in both the developing and injured, mature nervous system. In the developing nervous system, they do so by regulating naturally-occurring cell death in neural progenitor cells and in postmitotic neurons, acting to ensure the apoptosis of cells that either do not appropriately undergo the progenitor to postmitotic neuron transition, or that fail to compete for sufficient quantities of trophic support. Somewhat surprisingly, in developing postmitotic neurons, p53 plays a proapoptotic role, while a naturally-occurring, truncated form of p73, DeltaNp73, antagonizes p53 and plays an anti-apoptotic role. In the mature nervous system, numerous studies indicate that p53 is essential for the neuronal death in response to a variety of insults, including DNA damage, ischemia and excitotoxicity. It is likely that all of these insults culminate in DNA damage, which may well be a common trigger for neuronal apoptosis. In this regard, the signaling pathways that are responsible for triggering p53-dependent neuronal apoptosis are starting to be elucidated, and involve cell cycle deregulation and activation of the JNK pathway. Finally, accumulating evidence indicates that p53 is perturbed in the CNS in a number of neurodegenerative disorders, leading to the hypothesis that longterm oxidative damage and/or excitotoxicity ultimately trigger p53-dependent apoptosis in the chronically degenerating nervous system. PMID:11279533

  3. Cleavage of bid may amplify caspase-8-induced neuronal death following focally evoked limbic seizures.

    PubMed

    Henshall, D C; Bonislawski, D P; Skradski, S L; Lan, J Q; Meller, R; Simon, R P

    2001-08-01

    The mechanism by which seizures induce neuronal death is not completely understood. Caspase-8 is a key initiator of apoptosis via extrinsic, death receptor-mediated pathways; we therefore investigated its role in mediating seizure-induced neuronal death evoked by unilateral kainic acid injection into the amygdala of the rat, terminated after 40 min by diazepam. We demonstrate that cleaved (p18) caspase-8 was detectable immediately following seizure termination coincident with an increase in cleavage of the substrate Ile-Glu-Thr-Asp (IETD)-p-nitroanilide and the appearance of cleaved (p15) Bid. Expression of Fas and FADD, components of death receptor signaling, was increased following seizures. In vivo intracerebroventricular z-IETD-fluoromethyl ketone administration significantly reduced seizure-induced activities of caspases 8, 9, and 3 as well as reducing Bid and caspase-9 cleavage, cytochrome c release, DNA fragmentation, and neuronal death. These data suggest that intervention in caspase-8 and/or death receptor signaling may confer protection on the brain from the injurious effects of seizures. PMID:11493022

  4. Cytidine 5'-diphosphocholine (CDP-choline) adversely effects on pilocarpine seizure-induced hippocampal neuronal death.

    PubMed

    Kim, Jin Hee; Lee, Dong Won; Choi, Bo Young; Sohn, Min; Lee, Song Hee; Choi, Hui Chul; Song, Hong Ki; Suh, Sang Won

    2015-01-21

    Citicoline (CDP-choline; cytidine 5'-diphosphocholine) is an important intermediate in the biosynthesis of cell membrane phospholipids. Citicoline serves as a choline donor in the biosynthetic pathways of acetylcholine and neuronal membrane phospholipids, mainly phosphatidylcholine. The ability of citicoline to reverse neuronal injury has been tested in animal models of cerebral ischemia and clinical trials have been performed in stroke patients. However, no studies have examined the effect of citicoline on seizure-induced neuronal death. To clarify the potential therapeutic effects of citicoline on seizure-induced neuronal death, we used an animal model of pilocarpine-induced epilepsy. Temporal lobe epilepsy (TLE) was induced by intraperitoneal injection of pilocarpine (25mg/kg) in adult male rats. Citicoline (100 or 300 mg/kg) was injected into the intraperitoneal space two hours after seizure onset and a second injection was performed 24h after the seizure. Citicoline was injected once per day for one week after pilocarpine- or kainate-induced seizure. Neuronal injury and microglial activation were evaluated at 1 week post-seizure. Surprisingly, rather than offering protection, citicoline treatment actually enhanced seizure-induced neuronal death and microglial activation in the hippocampus compared to vehicle treated controls. Citicoline administration after seizure-induction increased immunoglobulin leakage via BBB disruption in the hippocampus compared with the vehicle-only group. To clarify if this adverse effect of citicoline is generalizable across alternative seizure models, we induced seizure by kainate injection (10mg/kg, i.p.) and then injected citicoline as in pilocarpine-induced seizure. We found that citicoline did not modulate kainate seizure-induced neuronal death, BBB disruption or microglial activation. These results suggest that citicoline may not have neuroprotective effects after seizure and that clinical application of citicoline after

  5. Role of nitric oxide and cyclic GMP in glutamate-induced neuronal death.

    PubMed

    Montoliu, C; Llansola, M; Monfort, P; Corbalan, R; Fernandez-Marticorena, I; Hernandez-Viadel, M L; Felipo, V

    2001-04-01

    Glutamate is the main excitatory neurotransmitter in mammals. However, excessive activation of glutamate receptors is neurotoxic, leading to neuronal degeneration and death. In many systems, including primary cultures of cerebellar neurons, glutamate neurotoxicity is mainly mediated by excessive activation of NMDA receptors, leading to increased intracellular calcium which binds to calmodulin and activates neuronal nitric oxide synthase (NOS), increasing nitric oxide (NO) which in turn activates guanylate cyclase and increases cGMP. Inhibition of NOS prevents glutamate neurotoxicity, indicating that NO mediates glutamate-induced neuronal death in this system. NO generating agents such as SNAP also induce neuronal death. Compounds that can act as "scavengers" of NO such as Croman 6 (CR-6) prevent glutamate neurotoxicity. The role of cGMP in the mediation of glutamate neurotoxicity remains controversial. Some reports indicate that cGMP mediates glutamate neurotoxicity while others indicate that cGMP is neuroprotective. We have studied the role of cGMP in the mediation of glutamate and NO neurotoxicity in cerebellar neurons. Inhibition of soluble guanylate cyclase prevents glutamate and NO neurotoxicity. There is a good correlation between inhibition of cGMP formation and neuroprotection. Moreover 8-Br-cGMP, a cell permeable analog of cGMP, induced neuronal death. These results indicate that increased intracellular cGMP is involved in the mechanism of neurotoxicity. Inhibitors of phosphodiesterase increased extracellular but not intracellular cGMP and prevented glutamate neurotoxicity. Addition of cGMP to the medium also prevented glutamate neurotoxicity. These results are compatible with a neurotoxic effect of increased intracellular cGMP and a neuroprotective effect of increased extracellular cGMP. PMID:14715472

  6. Mitochondrial complex I inhibition is not required for dopaminergic neuron death induced by rotenone, MPP+, or paraquat

    PubMed Central

    Choi, Won-Seok; Kruse, Shane E.; Palmiter, Richard D.; Xia, Zhengui

    2008-01-01

    Inhibition of mitochondrial complex I is one of the leading hypotheses for dopaminergic neuron death associated with Parkinson's disease (PD). To test this hypothesis genetically, we used a mouse strain lacking functional Ndufs4, a gene encoding a subunit required for complete assembly and function of complex I. Deletion of the Ndufs4 gene abolished complex I activity in midbrain mesencephalic neurons cultured from embryonic day (E) 14 mice, but did not affect the survival of dopaminergic neurons in culture. Although dopaminergic neurons were more sensitive than other neurons in these cultures to cell death induced by rotenone, MPP+, or paraquat treatments, the absence of complex I activity did not protect the dopaminergic neurons, as would be expected if these compounds act by inhibiting complex 1. In fact, the dopaminergic neurons were more sensitive to rotenone. These data suggest that dopaminergic neuron death induced by treatment with rotenone, MPP+, or paraquat is independent of complex I inhibition. PMID:18812510

  7. Ketamine-induced neuronal cell death in the perinatal rhesus monkey.

    PubMed

    Slikker, William; Zou, Xiaoju; Hotchkiss, Charlotte E; Divine, Rebecca L; Sadovova, Natalya; Twaddle, Nathan C; Doerge, Daniel R; Scallet, Andrew C; Patterson, Tucker A; Hanig, Joseph P; Paule, Merle G; Wang, Cheng

    2007-07-01

    Ketamine is widely used as a pediatric anesthetic. Studies in developing rodents have indicated that ketamine-induced anesthesia results in brain cell death. Additional studies are needed to determine if ketamine anesthesia results in brain cell death in the nonhuman primate and if so, to begin to define the stage of development and the duration of ketamine anesthesia necessary to produce brain cell death. Rhesus monkeys (N = 3 for each treatment and control group) at three stages of development (122 days of gestation and 5 and 35 postnatal days [PNDs]) were administered ketamine intravenously for 24 h to maintain a surgical anesthetic plane, followed by a 6-h withdrawal period. Similar studies were performed in PND 5 animals with 3 h of ketamine anesthesia. Animals were subsequently perfused and brain tissue processed for analyses. Ketamine (24-h infusion) produced a significant increase in the number of caspase 3-, Fluoro-Jade C- and silver stain-positive cells in the cortex of gestational and PND 5 animals but not in PND 35 animals. Electron microscopy indicated typical nuclear condensation and fragmentation in some neuronal cells, and cell body swelling was observed in others indicating that ketamine-induced neuronal cell death is most likely both apoptotic and necrotic in nature. Ketamine increased N-methyl-D-aspartate (NMDA) receptor NR1 subunit messenger RNA in the frontal cortex where enhanced cell death was apparent. Earlier developmental stages (122 days of gestation and 5 PNDs) appear more sensitive to ketamine-induced neuronal cell death than later in development (35 PNDs). However, a shorter duration of ketamine anesthesia (3 h) did not result in neuronal cell death in the 5-day-old monkey. PMID:17426105

  8. The cost of inpatient death associated with acute coronary syndrome

    PubMed Central

    Page, Robert L; Ghushchyan, Vahram; Van Den Bos, Jill; Gray, Travis J; Hoetzer, Greta L; Bhandary, Durgesh; Nair, Kavita V

    2016-01-01

    Background No studies have addressed the cost of inpatient mortality during an acute coronary syndrome (ACS) admission. Objective Compare ACS-related length of stay (LOS), total admission cost, and total admission cost by day of discharge/death for patients who died during an inpatient admission with a matched cohort discharged alive following an ACS-related inpatient stay. Methods Medical and pharmacy claims (2009–2012) were used to identify admissions with a primary diagnosis of ACS from patients with at least 6 months of continuous enrollment prior to an ACS admission. Patients who died during their ACS admission (deceased cohort) were matched (one-to-one) to those who survived (survived cohort) on age, sex, year of admission, Chronic Condition Index score, and prior revascularization. Mean LOS, total admission cost, and total admission cost by the day of discharge/death for the deceased cohort were compared with the survived cohort. A generalized linear model with log transformation was used to estimate the differences in the total expected incremental cost of an ACS admission and by the day of discharge/death between cohorts. A negative binomial model was used to estimate differences in the LOS between the two cohorts. Costs were inflated to 2013 dollars. Results A total of 1,320 ACS claims from patients who died (n=1,320) were identified and matched to 1,319 claims from the survived patients (n=1,319). The majority were men (68%) and mean age was 56.7±6.4 years. The LOS per claim for the deceased cohort was 47% higher (adjusted incidence rate ratio: 1.47, 95% confidence interval: 1.37–1.57) compared with claims from the survived cohort. Compared with the survived cohort, the adjusted mean incremental total cost of ACS admission claims from the deceased cohort was US$43,107±US$3,927 (95% confidence interval: US$35,411–US$50,803) higher. Conclusion Despite decreasing ACS hospitalizations, the economic burden of inpatient death remains high. PMID

  9. Activation of AMP-activated protein kinase by tributyltin induces neuronal cell death

    SciTech Connect

    Nakatsu, Yusuke; Kotake, Yaichiro Hino, Atsuko; Ohta, Shigeru

    2008-08-01

    AMP-activated protein kinase (AMPK), a member of the metabolite-sensing protein kinase family, is activated by energy deficiency and is abundantly expressed in neurons. The environmental pollutant, tributyltin chloride (TBT), is a neurotoxin, and has been reported to decrease cellular ATP in some types of cells. Therefore, we investigated whether TBT activates AMPK, and whether its activation contributes to neuronal cell death, using primary cultures of cortical neurons. Cellular ATP levels were decreased 0.5 h after exposure to 500 nM TBT, and the reduction was time-dependent. It was confirmed that most neurons in our culture system express AMPK, and that TBT induced phosphorylation of AMPK. Compound C, an AMPK inhibitor, reduced the neurotoxicity of TBT, suggesting that AMPK is involved in TBT-induced cell death. Next, the downstream target of AMPK activation was investigated. Nitric oxide synthase, p38 phosphorylation and Akt dephosphorylation were not downstream of TBT-induced AMPK activation because these factors were not affected by compound C, but glutamate release was suggested to be controlled by AMPK. Our results suggest that activation of AMPK by TBT causes neuronal death through mediating glutamate release.

  10. A Highly Toxic Cellular Prion Protein Induces a Novel, Nonapoptotic Form of Neuronal Death

    PubMed Central

    Christensen, Heather M.; Dikranian, Krikor; Li, Aimin; Baysac, Kathleen C.; Walls, Ken C.; Olney, John W.; Roth, Kevin A.; Harris, David A.

    2010-01-01

    Several different deletions within the N-terminal tail of the prion protein (PrP) induce massive neuronal death when expressed in transgenic mice. This toxicity is dose-dependently suppressed by coexpression of full-length PrP, suggesting that it results from subversion of a normal physiological activity of cellular PrP. We performed a combined biochemical and morphological analysis of Tg(ΔCR) mice, which express PrP carrying a 21-aa deletion (residues 105-125) within a highly conserved region of the protein. Death of cerebellar granule neurons in Tg(ΔCR) mice is not accompanied by activation of either caspase-3 or caspase-8 or by increased levels of the autophagy marker, LC3-II. In electron micrographs, degenerating granule neurons displayed a unique morphology characterized by heterogeneous condensation of the nuclear matrix without formation of discrete chromatin masses typical of neuronal apoptosis. Our data demonstrate that perturbations in PrP functional activity induce a novel, nonapoptotic, nonautophagic form of neuronal death whose morphological features are reminiscent of those associated with excitotoxic stress. PMID:20472884

  11. Induced expression of neuronal membrane attack complex and cell death by Alzheimer's beta-amyloid peptide.

    PubMed

    Shen, Y; Sullivan, T; Lee, C M; Meri, S; Shiosaki, K; Lin, C W

    1998-06-15

    beta-amyloid peptide (A beta) and complement-derived membrane attack complex (MAC) are co-localized in senile plaques of brains from Alzheimer's disease (AD) patients. But the relationship between A beta and complement activation is unclear. We have used human neurotypic cells, differentiated SH-SY5Y, as a model system to examine regulation of neuronal MAC expression and cell death by A beta. We demonstrated that mRNAs (C1q, C2, C3, C4, C5, C6, C7, C8 and C9) and proteins (C1q, C3 and C9) for the major components of the classical complement cascade are present in the SH-SY5Y neurotypic cells, indicating that neuronal cells can synthesize the necessary proteins required for MAC formation. Furthermore, immunocytochemical studies showed the A beta-induced neuronal MAC expression on the SH-SY5Y cells after CD59 was removed by PIPLC or blocked by anti-CD59 antibody. Meanwhile, increased A beta-induced neuronal cell death was observed following treatment with anti-CD59. Taken together, these results suggest that A beta activates neuronal complement cascade to induce MAC, and a deficiency of endogenous complement regulatory proteins, e.g., CD59, may increase the vulnerability of neurons to complement-mediated cytotoxicity. PMID:9689469

  12. Pro-NGF secreted by astrocytes promotes motor neuron cell death

    PubMed Central

    Domeniconi, Marco; Hempstead, Barbara L.; Chao, Moses V.

    2007-01-01

    It is well established that motor neurons depend for their survival on many trophic factors. In this study, we show that the precursor form of NGF (proNGF) can induce the death of motor neurons via engagement of the p75 neurotrophin receptor. The pro-apoptotic activity was dependent upon the presence of sortilin, a p75 co-receptor expressed on motor neurons. One potential source of proNGF is reactive astrocytes, which upregulate the levels of proNGF in response to peroxynitrite, an oxidant and producer of free radicals. Indeed, motor neuron viability was sensitive to conditioned media from cultured astrocytes treated with peroxynitrite and this effect could be reversed using a specific antibody against the pro-domain of proNGF. These results are consistent with a role for activated astrocytes and proNGF in the induction of motor neuron death and suggest a possible therapeutic target for the treatment of motor neuron disease. PMID:17188890

  13. The N-terminal Set-β Protein Isoform Induces Neuronal Death.

    PubMed

    Trakhtenberg, Ephraim F; Morkin, Melina I; Patel, Karan H; Fernandez, Stephanie G; Sang, Alan; Shaw, Peter; Liu, Xiongfei; Wang, Yan; Mlacker, Gregory M; Gao, Han; Velmeshev, Dmitry; Dombrowski, Susan M; Vitek, Michael P; Goldberg, Jeffrey L

    2015-05-22

    Set-β protein plays different roles in neurons, but the diversity of Set-β neuronal isoforms and their functions have not been characterized. The expression and subcellular localization of Set-β are altered in Alzheimer disease, cleavage of Set-β leads to neuronal death after stroke, and the full-length Set-β regulates retinal ganglion cell (RGC) and hippocampal neuron axon growth and regeneration in a subcellular localization-dependent manner. Here we used various biochemical approaches to investigate Set-β isoforms and their role in the CNS, using the same type of neurons, RGCs, across studies. We found multiple alternatively spliced isoforms expressed from the Set locus in purified RGCs. Set transcripts containing the Set-β-specific exon were the most highly expressed isoforms. We also identified a novel, alternatively spliced Set-β transcript lacking the nuclear localization signal and demonstrated that the full-length (∼39-kDa) Set-β is localized predominantly in the nucleus, whereas a shorter (∼25-kDa) Set-β isoform is localized predominantly in the cytoplasm. Finally, we show that an N-terminal Set-β cleavage product can induce neuronal death. PMID:25833944

  14. Regulation of Neuronal Cell Death by c-Abl-Hippo/MST2 Signaling Pathway

    PubMed Central

    Xiao, Lei; Bai, Yujie; Qu, Aiqin; Zheng, Zheng; Yuan, Zengqiang

    2012-01-01

    Background Mammalian Ste20-like kinases (MSTs) are the mammalian homologue of Drosophila hippo and play critical roles in regulation of cell death, organ size control, proliferation and tumorigenesis. MSTs exert pro-apoptotic function through cleavage, autophosphorylation and in turn phosphorylation of downstream targets, such as Histone H2B and FOXO (Forkhead box O). Previously we reported that protein kinase c-Abl mediates oxidative stress-induced neuronal cell death through phosphorylating MST1 at Y433, which is not conserved among mammalian MST2, Drosophila Hippo and C.elegans cst-1/2. Methodology/Principal Findings Using immunoblotting, in vitro kinase and cell death assay, we demonstrate that c-Abl kinase phosphorylates MST2 at an evolutionarily conserved site, Y81, within the kinase domain. We further show that the phosphorylation of MST2 by c-Abl leads to the disruption of the interaction with Raf-1 proteins and the enhancement of homodimerization of MST2 proteins. It thereby enhances the MST2 activation and induces neuronal cell death. Conclusions/Significance The identification of the c-Abl tyrosine kinase as a novel upstream activator of MST2 suggests that the conserved c-Abl-MST signaling cascade plays an important role in oxidative stress-induced neuronal cell death. PMID:22590567

  15. NMDAR-Mediated Hippocampal Neuronal Death is Exacerbated by Activities of ASIC1a

    PubMed Central

    Gao, Su; Yu, Yang; Ma, Zhi-Yuan; Sun, Hui; Zhang, Yong-Li; Wang, Xing-Tao; Wang, Chaoyun; Fan, Wei-Ming; Zheng, Qing-Yin

    2015-01-01

    NMDARs and ASIC1a both exist in central synapses and mediate important physiological and pathological conditions, but the functional relationship between them is unclear. Here we report several novel findings that may shed light on the functional relationship between these two ion channels in the excitatory postsynaptic membrane of mouse hippocampus. Firstly, NMDAR activation induced by either NMDA or OGD led to increased [Ca2+]i and greater apoptotic and necrotic cell deaths in cultured hippocampal neurons; these cell deaths were prevented by application of NMDAR antagonists. Secondly, ASIC1a activation induced by pH 6.0 extracellular solution (ECS) showed similar increases in apoptotic and necrotic cell deaths; these cell deaths were prevented by ASIC1a antagonists, and also by NMDAR antagonists. Since increased [Ca2+]i leads to increased cell deaths and since NMDAR exhibits much greater calcium permeability than ASIC1a, these data suggest that ASIC1a-induced neuronal death is mediated through activation of NMDARs. Thirdly, treatment of hippocampal cultures with both NMDA and acidic ECS induced greater degrees of cell deaths than either NMDA or acidic ECS treatment alone. These results suggest that ASIC1a activation up-regulates NMDAR function. Additional data supporting the functional relationship between ASIC1a and NMDAR are found in our electrophysiology experiments in hippocampal slices, where stimulation of ASIC1a induced a marked increase in NMDAR EPSC amplitude, and inhibition of ASIC1a resulted in a decrease in NMDAR EPSC amplitude. In summary, we present evidence that ASIC1a activity facilitates NMDAR function and exacerbates NMDAR-mediated neuronal death in pathological conditions. These findings are invaluable to the search for novel therapeutic targets in the treatment of brain ischemia. PMID:25947342

  16. Autophagy activation and enhanced mitophagy characterize the Purkinje cells of pcd mice prior to neuronal death

    PubMed Central

    Chakrabarti, Lisa; Eng, Jeremiah; Ivanov, Nishi; Garden, Gwenn A; La Spada, Albert R

    2009-01-01

    Purkinje cells are a class of specialized neurons in the cerebellum, and are among the most metabolically active of all neurons, as they receive immense synaptic stimulation, and provide the only efferent output from the cerebellum. Degeneration of Purkinje cells is a common feature of inherited ataxias in humans and mice. To understand Purkinje neuron degeneration, investigators have turned to naturally occurring Purkinje cell degeneration phenotypes in mice to identify key regulatory proteins and cellular pathways. The Purkinje cell degeneration (pcd) mouse is a recessive mutant characterized by complete and dramatic post-natal, cell autonomous Purkinje neuron degeneration and death. As the basis of Purkinje cell death in pcd is unresolved, and contradictory data has emerged for the role of autophagy in Purkinje cell degeneration, we studied the mechanism of Purkinje cell death in pcd mice. BAX null status did not suppress Purkinje neuron death in pcd mice, indicating that classic apoptosis is not responsible for Purkinje cell loss. Interestingly, LC3 Western blot analysis and GFP-LC3 immunostaining of degenerating pcd cerebellum revealed activation of the autophagy pathway. Ultrastructural studies confirmed increased autophagy pathway activity in Purkinje cells, and yielded evidence for mitophagy, in agreement with LC3 immunoblotting of cerebellar fractions. As p62 levels were decreased in pcd cerebellum, our findings suggest that pcd Purkinje cell neurons can execute effective autophagy. However, our results support a role for dysregulated autophagy activation in pcd, and suggest that increased or aberrant mitophagy contributes to the Purkinje cell degeneration in pcd mice. PMID:19640278

  17. TRPV1 Activation in Primary Cortical Neurons Induces Calcium-Dependent Programmed Cell Death.

    PubMed

    Song, Juhyun; Lee, Jun Hong; Lee, Sung Ho; Park, Kyung Ah; Lee, Won Taek; Lee, Jong Eun

    2013-03-01

    Transient receptor potential cation channel, subfamily V, member 1 (TRPV1, also known as vanilloid receptor 1) is a receptor that detects capsaicin, a pungent component of chili peppers, and noxious heat. Although its function in the primary nociceptor as a pain receptor is well established, whether TRPV1 is expressed in the brain is still under debate. In this study, the responses of primary cortical neurons were investigated. Here, we report that 1) capsaicin induces caspase-3-dependent programmed cell death, which coincides with increased production of nitric oxide and peroxynitrite ; that 2) the prolonged capsaicin treatment induces a steady increase in the degree of capase-3 activation, which is prevented by the removal of capsaicin; 3) and that blocking calcium entry and calcium-mediated signaling prevents capsaicin-induced cell death. These results indicate that cortical neurons express TRPV1 whose prolonged activation causes cell death. PMID:23585723

  18. Progressive degeneration of dopaminergic neurons through TRP channel-induced cell death.

    PubMed

    Nagarajan, Archana; Ning, Ye; Reisner, Kaja; Buraei, Zafir; Larsen, Jan Petter; Hobert, Oliver; Doitsidou, Maria

    2014-04-23

    Progressive neurodegenerative diseases are among the most frequently occurring aging-associated human pathologies. In a screen for Caenorhabditis elegans mutant animals that lack their normal complement of dopaminergic neurons, we identified two strains with progressive loss of dopaminergic neurons during postembryonic life. Through whole-genome sequencing we show that both strains harbor dominant (d), gain-of-function mutations in the Transient Receptor Potential (TRP) mechanosensory channel trp-4, a member of the invertebrate and vertebrate TRPN-type of the TRP family channels. Gain-of-function mutations in TRP channels have not been previously implicated in dopaminergic neuronal degeneration. We show that trp-4(d) induces cell death in dopamine neurons through a defined, calcium-related downstream pathway. PMID:24760834

  19. Cofilin Inhibition Restores Neuronal Cell Death in Oxygen-Glucose Deprivation Model of Ischemia.

    PubMed

    Madineni, Anusha; Alhadidi, Qasim; Shah, Zahoor A

    2016-03-01

    Ischemia is a condition associated with decreased blood supply to the brain, eventually leading to death of neurons. It is associated with a diverse cascade of responses involving both degenerative and regenerative mechanisms. At the cellular level, the changes are initiated prominently in the neuronal cytoskeleton. Cofilin, a cytoskeletal actin severing protein, is known to be involved in the early stages of apoptotic cell death. Evidence supports its intervention in the progression of disease states like Alzheimer's and ischemic kidney disease. In the present study, we have hypothesized the possible involvement of cofilin in ischemia. Using PC12 cells and mouse primary cultures of cortical neurons, we investigated the potential role of cofilin in ischemia in two different in vitro ischemic models: chemical induced oxidative stress and oxygen-glucose deprivation/reperfusion (OGD/R). The expression profile studies demonstrated a decrease in phosphocofilin levels in all models of ischemia, implying stress-induced cofilin activation. Furthermore, calcineurin and slingshot 1L (SSH) phosphatases were found to be the signaling mediators of the cofilin activation. In primary cultures of cortical neurons, cofilin was found to be significantly activated after 1 h of OGD. To delineate the role of activated cofilin in ischemia, we knocked down cofilin by small interfering RNA (siRNA) technique and tested the impact of cofilin silencing on neuronal viability. Cofilin siRNA-treated neurons showed a significant reduction of cofilin levels in all treatment groups (control, OGD, and OGD/R). Additionally, cofilin siRNA-reduced cofilin mitochondrial translocation and caspase 3 cleavage, with a concomitant increase in neuronal viability. These results strongly support the active role of cofilin in ischemia-induced neuronal degeneration and apoptosis. We believe that targeting this protein mediator has a potential for therapeutic intervention in ischemic brain injury and stroke

  20. Proneurotrophin-3 may induce Sortilin dependent death in inner ear neurons

    PubMed Central

    Tauris, Jacob; Gustafsen, Camilla; Christensen, Erik Ilsø; Jansen, Pernille; Nykjaer, Anders; Nyengaard, Jens R.; Teng, Kenneth K.; Schwarz, Elisabeth; Ovesen, Therese; Madsen, Peder; Petersen, Claus Munck

    2010-01-01

    The precursor of the neurotrophin NGF (proNGF) serves physiological functions distinct from its mature counterpart as it induces neuronal apoptosis through activation of a p75 neurotrophin receptor (p75NTR) and Sortilin death-signalling complex. The neurotrophins BDNF and NT3 provide essential trophic support to auditory neurons. Injury to the neurotrophin secreting cells in the inner ear is followed by irreversible degeneration of spiral ganglion neurons with consequences such as impaired hearing or deafness. Lack of mature neurotrophins may explain the degeneration of spiral ganglion neurons, but another mechanism is possible since unprocessed proNTs released from the injured cells may contribute to the degeneration by induction of apoptosis. Recent studies demonstrate that proBDNF, like proNGF, is a potent inducer of Sortilin:p75NTR mediated apoptosis. In addition, a coincident upregulation of proBDNF and p75NTR has been observed in degenerating spiral ganglion neurons, but the Sortilin expression in the inner ear is unresolved. Here we demonstrate that Sortilin and p75NTR are coexpressed in neurons of the neonatal inner ear. Furthermore, we establish that proNT3 exhibits high affinity binding to Sortilin and has the capacity to enhance cell surface Sortilin:p75NTR complex formation as well as to mediate apoptosis in neurons coexpressing p75NTR and Sortilin. Based on examination of wt and Sortilin deficient mouse embryos, Sortilin does not significantly influence the developmental selection of spiral ganglion neurons. However, our results suggest that proNT3 and proBDNF may play important roles in the response to noise-induced injuries or ototoxic damage via the Sortilin:p75NTR death-signalling complex. PMID:21261755

  1. Reduced expression of plasma membrane calcium ATPase 2 and collapsin response mediator protein 1 promotes death of spinal cord neurons.

    PubMed

    Kurnellas, M P; Li, H; Jain, M R; Giraud, S N; Nicot, A B; Ratnayake, A; Heary, R F; Elkabes, S

    2010-09-01

    The mechanisms underlying neuronal pathology and death in the spinal cord (SC) during inflammation remain elusive. We previously showed the important role of plasma membrane calcium ATPases (PMCAs) in the survival of SC neurons, in vitro. We also postulated that a decrease in PMCA2 expression could cause neuronal death during experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. The current studies were undertaken to define the specific contribution of PMCA2 to degeneration of SC neurons, the effectors downstream to PMCA2 mediating neuronal death and the triggers that reduce PMCA2 expression. We report that knockdown of PMCA2 in SC neurons decreases collapsin response mediator protein 1 (CRMP1) levels. This is followed by cell death. Silencing of CRMP1 expression also leads to neuronal loss. Kainic acid reduces both PMCA2 and CRMP1 levels and induces neuronal death. Administration of an alpha-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate (AMPA)/kainate receptor antagonist, at onset or peak of EAE, restores the decreased PMCA2 and CRMP1 levels to control values and ameliorates clinical deficits. Thus, our data link the reduction in PMCA2 expression with perturbations in the expression of CRMP1 and the ensuing death of SC neurons. This represents an additional mechanism underlying AMPA/kainate receptor-mediated excitotoxicity with relevance to neurodegeneration in EAE. PMID:20489728

  2. Methoxychlor and fenvalerate induce neuronal death by reducing GluR2 expression.

    PubMed

    Umeda, Kanae; Kotake, Yaichiro; Miyara, Masatsugu; Ishida, Keishi; Sanoh, Seigo; Ohta, Shigeru

    2016-04-01

    GluR2, an α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor subunit, plays important roles in neuronal survival. We previously showed that exposure of cultured rat cortical neurons to several chemicals decreases GluR2 protein expression, leading to neuronal toxicity. Methoxychlor, the bis-p-methoxy derivative of dichlorodiphenyltrichloroethane, and fenvalerate, a synthetic pyrethroid chemical, have been used commercially as agricultural pesticides in several countries. In this study, we investigated the effects of long-term methoxychlor and fenvalerate exposure on neuronal glutamate receptors. Treatment of cultured rat cortical neurons with 1 or 10 µM methoxychlor and fenvalerate for 9 days selectively decreased GluR2 protein expression; the expression of other AMPA receptor subunits GluR1, GluR3, and GluR4 did not change under the same conditions. Importantly, the decreases in GluR2 protein expression were also observed on the cell surface membrane where AMPA receptors typically function. In addition, both chemicals decreased neuronal viability, which was blocked by pretreatment with 1-naphtylacetylspermine, an antagonist of GluR2-lacking AMPA receptors, and MK-801, an N-methyl-d-aspartate (NMDA) receptor antagonist. These results suggest that long-term exposure to methoxychlor and fenvalerate decreases GluR2 protein expression, leading to neuronal death via overactivation of GluR2-lacking AMPA and NMDA receptors. PMID:26961610

  3. Procaspase-activating compound 1 induces a caspase-3-dependent cell death in cerebellar granule neurons

    SciTech Connect

    Aziz, Gulzeb; Akselsen, Oyvind W.; Hansen, Trond V.; Paulsen, Ragnhild E.

    2010-09-15

    Procaspase-activating compound 1, PAC-1, has been introduced as a direct activator of procaspase-3 and has been suggested as a therapeutic agent against cancer. Its activation of procaspase-3 is dependent on the chelation of zinc. We have tested PAC-1 and an analogue of PAC-1 as zinc chelators in vitro as well as their ability to activate caspase-3 and induce cell death in chicken cerebellar granule neuron cultures. These neurons are non-dividing, primary cells with normal caspase-3. The results reported herein show that PAC-1 chelates zinc, activates procaspase-3, and leads to caspase-3-dependent cell death in neurons, as the specific caspase-3-inhibitor Ac-DEVD-cmk inhibited both the caspase-3 activity and cell death. Thus, chicken cerebellar granule neurons is a suitable model to study mechanisms of interference with apoptosis of PAC-1 and similar compounds. Furthermore, the present study also raises concern about potential neurotoxicity of PAC-1 if used in cancer therapy.

  4. Carbon monoxide-induced delayed amnesia, delayed neuronal death and change in acetylcholine concentration in mice

    SciTech Connect

    Nabeshima, T.; Katoh, A.; Ishimaru, H.; Yoneda, Y.; Ogita, K.; Murase, K.; Ohtsuka, H.; Inari, K.; Fukuta, T.; Kameyama, T. )

    1991-01-01

    We investigated the interrelationship of delayed amnesia, delayed neuronal death and changes in acetylcholine concentration induced by carbon monoxide (CO)-exposure in mice. In the test for retention of the passive avoidance task, amnesia was observed 5 and 7 days after CO-exposure when the mice were exposed to CO 1 day after training; in the case when the mice were exposed to CO 5 and 7 days before training, amnesia was also observed in a retention test given 1 day after training. The number of pyramidal cells in the hippocampal CA1 subfield was lower than that of the control 3, 5 and 7 days after CO-exposure. But the neurodegeneration in the parietal cortex, area 1, was not observed until 7 days after CO-exposure. The findings indicated that the amnesia and the neuronal death were produced after a delay when the mice were exposed to CO. In addition, the delayed amnesia was closely related to the delayed neuronal death in the hippocampal CA1 subfield. Moreover, (3H)glutamate and (3H)glycine binding sites did not change after CO-exposure but, 7 days after CO-exposure, the concentration of acetylcholine and the binding of (3H)quinuclidinyl benzilate in the frontal cortex and the striatum were found to have significantly changed, but those in the hippocampus did not show significant change. Therefore, we suggest that delayed amnesia induced by CO-exposure may result from delayed neuronal death in the hippocampal CA1 subfield and dysfunction in the acetylcholinergic neurons, in the frontal cortex, the striatum and/or the hippocampus.

  5. Ionotropic receptors and ion channels in ischemic neuronal death and dysfunction

    PubMed Central

    Weilinger, Nicholas L; Maslieieva, Valentyna; Bialecki, Jennifer; Sridharan, Sarup S; Tang, Peter L; Thompson, Roger J

    2013-01-01

    Loss of energy supply to neurons during stroke induces a rapid loss of membrane potential that is called the anoxic depolarization. Anoxic depolarizations result in tremendous physiological stress on the neurons because of the dysregulation of ionic fluxes and the loss of ATP to drive ion pumps that maintain electrochemical gradients. In this review, we present an overview of some of the ionotropic receptors and ion channels that are thought to contribute to the anoxic depolarization of neurons and subsequently, to cell death. The ionotropic receptors for glutamate and ATP that function as ligand-gated cation channels are critical in the death and dysfunction of neurons. Interestingly, two of these receptors (P2X7 and NMDAR) have been shown to couple to the pannexin-1 (Panx1) ion channel. We also discuss the important roles of transient receptor potential (TRP) channels and acid-sensing ion channels (ASICs) in responses to ischemia. The central challenge that emerges from our current understanding of the anoxic depolarization is the need to elucidate the mechanistic and temporal interrelations of these ion channels to fully appreciate their impact on neurons during stroke. PMID:22864302

  6. Cell Death, Neuronal Plasticity and Functional Loading in the Development of the Central Nervous System

    NASA Technical Reports Server (NTRS)

    Keefe, J. R.

    1985-01-01

    Research on the precise timing and regulation of neuron production and maturation in the vestibular and visual systems of Wistar rats and several inbred strains of mice (C57B16 and Pallid mutant) concentrated upon establishing a timing baseline for mitotic development of the neurons of the vestibular nuclei and the peripheral vestibular sensory structures (maculae, cristae). This involved studies of the timing and site of neuronal cell birth and preliminary studies of neuronal cell death in both central and peripheral elements of the mammalian vestibular system. Studies on neuronal generation and maturation in the retina were recently added to provide a mechanism for more properly defining the in utero' developmental age of the individual fetal subject and to closely monitor potential transplacental effects of environmentally stressed maternal systems. Information is given on current efforts concentrating upon the (1) perinatal period of development (E18 thru P14) and (2) the role of cell death in response to variation in the functional loading of the vestibular and proprioreceptive systems in developing mammalian organisms.

  7. Cardiac arrest triggers hippocampal neuronal death through autophagic and apoptotic pathways.

    PubMed

    Cui, Derong; Shang, Hanbing; Zhang, Xiaoli; Jiang, Wei; Jia, Xiaofeng

    2016-01-01

    The mechanism of neuronal death induced by ischemic injury remains unknown. We investigated whether autophagy and p53 signaling played a role in the apoptosis of hippocampal neurons following global cerebral ischemia-reperfusion (I/R) injury, in a rat model of 8-min asphyxial cardiac arrest (CA) and resuscitation. Increased autophagosome numbers, expression of lysosomal cathepsin B, cathepsin D, Beclin-1, and microtubule-associated protein light chain 3 (LC3) suggested autophagy in hippocampal cells. The expression of tumor suppressor protein 53 (p53) and its target genes: Bax, p53-upregulated modulator of apoptosis (PUMA), and damage-regulated autophagy modulator (DRAM) were upregulated following CA. The p53-specific inhibitor pifithrin-α (PFT-α) significantly reduced the expression of pro-apoptotic proteins (Bax and PUMA) and autophagic proteins (LC3-II and DRAM) that generally increase following CA. PFT-α also reduced hippocampal neuronal damage following CA. Similarly, 3-methyladenine (3-MA), which inhibits autophagy and bafilomycin A1 (BFA), which inhibits lysosomes, significantly inhibited hippocampal neuronal damage after CA. These results indicate that CA affects both autophagy and apoptosis, partially mediated by p53. Autophagy plays a significant role in hippocampal neuronal death induced by cerebral I/R following asphyxial-CA. PMID:27273382

  8. Cardiac arrest triggers hippocampal neuronal death through autophagic and apoptotic pathways

    PubMed Central

    Cui, Derong; Shang, Hanbing; Zhang, Xiaoli; Jiang, Wei; Jia, Xiaofeng

    2016-01-01

    The mechanism of neuronal death induced by ischemic injury remains unknown. We investigated whether autophagy and p53 signaling played a role in the apoptosis of hippocampal neurons following global cerebral ischemia-reperfusion (I/R) injury, in a rat model of 8-min asphyxial cardiac arrest (CA) and resuscitation. Increased autophagosome numbers, expression of lysosomal cathepsin B, cathepsin D, Beclin-1, and microtubule-associated protein light chain 3 (LC3) suggested autophagy in hippocampal cells. The expression of tumor suppressor protein 53 (p53) and its target genes: Bax, p53-upregulated modulator of apoptosis (PUMA), and damage-regulated autophagy modulator (DRAM) were upregulated following CA. The p53-specific inhibitor pifithrin-α (PFT-α) significantly reduced the expression of pro-apoptotic proteins (Bax and PUMA) and autophagic proteins (LC3-II and DRAM) that generally increase following CA. PFT-α also reduced hippocampal neuronal damage following CA. Similarly, 3-methyladenine (3-MA), which inhibits autophagy and bafilomycin A1 (BFA), which inhibits lysosomes, significantly inhibited hippocampal neuronal damage after CA. These results indicate that CA affects both autophagy and apoptosis, partially mediated by p53. Autophagy plays a significant role in hippocampal neuronal death induced by cerebral I/R following asphyxial-CA. PMID:27273382

  9. Nuclear translocation of histone deacetylase 4 induces neuronal death in stroke.

    PubMed

    Yuan, Hui; Denton, Kyle; Liu, Lin; Li, Xue-Jun; Benashski, Sharon; McCullough, Louise; Li, Jun

    2016-07-01

    Mounting evidence suggests that epigenetic modifications play critical roles in the survival/death of stressed neurons. Chief among these modifications is the deacetylation of histones within the chromatin by histone deacetylases (HDACs). HDAC4 is highly expressed in neurons and is usually trapped in cytosol. However, tightly regulated signal-dependent shuttling of this molecule between cytosol and nucleus occurs. Here, we studied the intracellular trafficking of HDAC4 and regulatory mechanisms during stroke. HDAC4 translocated from the cytosol into the nucleus of neurons in response to stroke induced by middle cerebral artery occlusion (MCAO) in mice. Similar translocation was seen after oxygen-glucose deprivation (OGD) in cultured mouse neurons. Expression of nuclear-restricted HDAC4 increased neuronal death after OGD and worsened infarcts and functional deficits in mice following MCAO; however, expression of cytosolic-restricted HDAC4 did not affect outcome after ischemia. In contrast, HDAC4 knockdown with siRNA improved neuronal survival after OGD. Furthermore, expression of nuclear-restricted HDAC4 reduced the acetylation of histones 3 and 4 as well as the levels of pro-survival downstream molecules after OGD. Finally, genetic deletion of calcium/calmodulin-dependent protein kinase IV (CaMKIV) increased the nuclear accumulation of HDAC4 in MCAO model, while overexpression of CaMKIV reduced the levels of nuclear HDAC4 following OGD. When HDAC4 was inhibited, the neuroprotection provided by CaMKIV overexpression was absent during OGD. Our data demonstrate a detrimental role of the nuclear accumulation of HDAC4 following stroke and identify CaMKIV as a key regulator of neuronal intracellular HDAC4 trafficking during stroke. PMID:26969532

  10. Neuropilin 1 directly interacts with Fer kinase to mediate semaphorin 3A-induced death of cortical neurons.

    PubMed

    Jiang, Susan X; Whitehead, Shawn; Aylsworth, Amy; Slinn, Jacqueline; Zurakowski, Bogdan; Chan, Kenneth; Li, Jianjun; Hou, Sheng T

    2010-03-26

    Neuropilins (NRPs) are receptors for the major chemorepulsive axonal guidance cue semaphorins (Sema). The interaction of Sema3A/NRP1 during development leads to the collapse of growth cones. Here we show that Sema3A also induces death of cultured cortical neurons through NRP1. A specific NRP1 inhibitory peptide ameliorated Sema3A-evoked cortical axonal retraction and neuronal death. Moreover, Sema3A was also involved in cerebral ischemia-induced neuronal death. Expression levels of Sema3A and NRP1, but not NRP2, were significantly increased early during brain reperfusion following transient focal cerebral ischemia. NRP1 inhibitory peptide delivered to the ischemic brain was potently neuroprotective and prevented the loss of motor functions in mice. The integrity of the injected NRP1 inhibitory peptide into the brain remained unchanged, and the intact peptide permeated the ischemic hemisphere of the brain as determined using MALDI-MS-based imaging. Mechanistically, NRP1-mediated axonal collapse and neuronal death is through direct and selective interaction with the cytoplasmic tyrosine kinase Fer. Fer RNA interference effectively attenuated Sema3A-induced neurite retraction and neuronal death in cortical neurons. More importantly, down-regulation of Fer expression using Fer-specific RNA interference attenuated cerebral ischemia-induced brain damage. Together, these studies revealed a previously unknown function of NRP1 in signaling Sema3A-evoked neuronal death through Fer in cortical neurons. PMID:20133938

  11. Neuroprotective effects of silymarin on ischemia-induced delayed neuronal cell death in rat hippocampus.

    PubMed

    Hirayama, Koki; Oshima, Hideki; Yamashita, Akiko; Sakatani, Kaoru; Yoshino, Atsuo; Katayama, Yoichi

    2016-09-01

    We examined the effects of silymarin, which was extracted from Silybum marianum, on delayed neuronal cell death in the rat hippocampus. Rats were divided into four groups: sham-operated rats (sham group), rats which underwent ischemic surgery (control group), rats which were treated with silymarin before and after ischemic surgery (pre group), and rats which were treated with silymarin after ischemic surgery only (post group). We performed the ischemic surgery by occluding the bilateral carotid arteries for 20min and sacrificed the rats one week after the surgery. Silymarin was administered orally at 200mg/kg body weight. Smaller numbers of delayed cell deaths were noted in the rat CA1 region of the pre- and post-groups, and no significant difference was observed between these groups. There were few apoptotic cell deaths in all groups. Compared to the control group, significantly fewer cell deaths by autophagy were found in the pre- and post-group. We concluded that silymarin exerts a preservation effect on delayed neuronal cell death in the rat hippocampus and this effect has nothing to do with the timing of administering of silymarin. PMID:27312091

  12. Caspase Inhibition Extends the Commitment to Neuronal Death Beyond Cytochrome c Release to the Point of Mitochondrial Depolarization

    PubMed Central

    Deshmukh, Mohanish; Kuida, Keisuke; Johnson, Eugene M.

    2000-01-01

    Nerve growth factor (NGF) deprivation induces a Bax-dependent, caspase-dependent programmed cell death in sympathetic neurons. We examined whether the release of cytochrome c was accompanied by the loss of mitochondrial membrane potential during sympathetic neuronal death. NGF- deprived, caspase inhibitor–treated mouse sympathetic neurons maintained mitochondrial membrane poten-tial for 25–30 h after releasing cytochrome c. NGF- deprived sympathetic neurons became committed to die, as measured by the inability of cells to be rescued by NGF readdition, at the time of cytochrome c release. In the presence of caspase inhibitor, however, this commitment to death was extended beyond the point of cytochrome c release, but only up to the subsequent point of mitochondrial membrane potential loss. Caspase-9 deficiency also arrested NGF-deprived sympathetic neurons after release of cytochrome c, and permitted these neurons to be rescued with NGF readdition. Commitment to death in the NGF-deprived, caspase- 9–deficient sympathetic neurons was also coincident with the loss of mitochondrial membrane potential. Thus, caspase inhibition extended commitment to death in trophic factor–deprived sympathetic neurons and allowed recovery of neurons arrested after the loss of cytochrome c, but not beyond the subsequent loss of mitochondrial membrane potential. PMID:10893262

  13. Frequency and Factors Associated with Unexpected Death in an Acute Palliative Care Unit: Expect the Unexpected

    PubMed Central

    Bruera, Sebastian; Chisholm, Gary; Santos, Renata Dos; Bruera, Eduardo; Hui, David

    2015-01-01

    Context Few studies have examined the frequency of unexpected death and its associated factors in a palliative care setting. Objectives To determine the frequency of unexpected death in two acute palliative care units (APCUs); to compare the frequency of signs of impending death between expected and unexpected deaths; and to determine the predictors associated with unexpected death. Methods In this prospective, longitudinal, observational study, consecutive patients admitted to two APCUs were enrolled and physical signs of impending death were documented twice daily until discharge or death. Physicians were asked to complete a survey within 24 hours of APCU death. The death was considered unexpected if the physician answered “yes” to the question “Were you surprised by the timing of the death?” Results In total, 193 of 203 after-death assessments (95%) were collected for analysis. Nineteen of 193 patients died unexpectedly (10%). Signs of impending death, including nonreactive pupils, inability to close eyelids, decreased response to verbal stimuli, drooping of nasolabial folds, peripheral cyanosis, pulselessness of the radial artery, and respiration with mandibular movement, were documented more frequently in expected deaths than unexpected deaths (P < 0.05). Longer disease duration was associated with unexpected death (33 months vs. 12 months, P=0.009). Conclusion Unexpected death occurred in an unexpectedly high proportion of patients in the APCU setting, and was associated with fewer signs of impending death. Our findings highlight the need for palliative care teams to be prepared for the unexpected. PMID:25499421

  14. Apoptosis-inducing factor substitutes for caspase executioners in NMDA-triggered excitotoxic neuronal death.

    PubMed

    Wang, Hongmin; Yu, Seong-Woon; Koh, David W; Lew, Jasmine; Coombs, Carmen; Bowers, William; Federoff, Howard J; Poirier, Guy G; Dawson, Ted M; Dawson, Valina L

    2004-12-01

    The profound neuroprotection observed in poly(ADP-ribose) polymerase-1 (PARP-1) null mice to ischemic and excitotoxic injury positions PARP-1 as a major mediator of neuronal cell death. We report here that apoptosis-inducing factor (AIF) mediates PARP-1-dependent glutamate excitotoxicity in a caspase-independent manner after translocation from the mitochondria to the nucleus. In primary murine cortical cultures, neurotoxic NMDA exposure triggers AIF translocation, mitochondrial membrane depolarization, and phosphatidyl serine exposure on the cell surface, which precedes cytochrome c release and caspase activation. NMDA neurotoxicity is not affected by broad-spectrum caspase inhibitors, but it is prevented by Bcl-2 overexpression and a neutralizing antibody to AIF. These results link PARP-1 activation with AIF translocation in NMDA-triggered excitotoxic neuronal death and provide a paradigm in which AIF can substitute for caspase executioners. PMID:15574746

  15. The effects of D-allose on transient ischemic neuronal death and analysis of its mechanism.

    PubMed

    Liu, Yanan; Nakamura, Takehiro; Toyoshima, Tetsuhiko; Shinomiya, Aya; Tamiya, Takashi; Tokuda, Masaaki; Keep, Richard F; Itano, Toshifumi

    2014-10-01

    The present study investigates the neuroprotective effects of d-allose, a rare sugar, against ischemia/reperfusion injury in a gerbil model. Transient forebrain ischemia was induced by occlusion of the bilateral common carotid arteries for 5 min. D-Allose was intravenously injected before and after ischemia (200 mg/kg). Extracellular glutamate and lactate release from the gerbil brain, and PO₂ profiles were monitored during ischemia and reperfusion. We also examined neuronal death and oxidative damage in the hippocampus one week after ischemia reperfusion, and investigated functional outcome. D-Allose administration suppressed glutamate and lactate release compared to vehicle controls. Brain damage, 8-OHdG levels (a marker of oxidative stress) and locomotor activities were significantly decreased by D-allose treatment. The present results suggest that d-allose reduces delayed neuronal death and behavioral deficits after transient ischemia by changing cerebral metabolism and inhibiting oxidative stress. PMID:25445611

  16. Impaired autophagy flux is associated with neuronal cell death after traumatic brain injury

    PubMed Central

    Sarkar, Chinmoy; Zhao, Zaorui; Aungst, Stephanie; Sabirzhanov, Boris; Faden, Alan I; Lipinski, Marta M

    2015-01-01

    Dysregulation of autophagy contributes to neuronal cell death in several neurodegenerative and lysosomal storage diseases. Markers of autophagy are also increased after traumatic brain injury (TBI), but its mechanisms and function are not known. Following controlled cortical impact (CCI) brain injury in GFP-Lc3 (green fluorescent protein-LC3) transgenic mice, we observed accumulation of autophagosomes in ipsilateral cortex and hippocampus between 1 and 7 d. This accumulation was not due to increased initiation of autophagy but rather to a decrease in clearance of autophagosomes, as reflected by accumulation of the autophagic substrate SQSTM1/p62 (sequestosome 1). This was confirmed by ex vivo studies, which demonstrated impaired autophagic flux in brain slices from injured as compared to control animals. Increased SQSTM1 peaked at d 1–3 but resolved by d 7, suggesting that the defect in autophagy flux is temporary. The early impairment of autophagy is at least in part caused by lysosomal dysfunction, as evidenced by lower protein levels and enzymatic activity of CTSD (cathepsin D). Furthermore, immediately after injury both autophagosomes and SQSTM1 accumulated predominantly in neurons. This was accompanied by appearance of SQSTM1 and ubiquitin-positive puncta in the affected cells, suggesting that, similar to the situation observed in neurodegenerative diseases, impaired autophagy may contribute to neuronal injury. Consistently, GFP-LC3 and SQSTM1 colocalized with markers of both caspase-dependent and caspase-independent cell death in neuronal cells proximal to the injury site. Taken together, our data indicated for the first time that autophagic clearance is impaired early after TBI due to lysosomal dysfunction, and correlates with neuronal cell death. PMID:25484084

  17. Uncoupling of ATP-depletion and cell death in human dopaminergic neurons.

    PubMed

    Pöltl, Dominik; Schildknecht, Stefan; Karreman, Christiaan; Leist, Marcel

    2012-08-01

    The mitochondrial inhibitor 1-methyl-4-phenylpyridinium (MPP(+)) is the toxicologically relevant metabolite of 1-methyl-4-phenyltetrahydropyridine (MPTP), which causes relatively selective degeneration of dopaminergic neurons in the substantia nigra. Dopaminergic LUHMES cells were used to investigate whether ATP-depletion can be uncoupled from cell death as a downstream event in these fully post-mitotic human neurons. Biochemical assays indicated that in the homogeneously differentiated cell cultures, MPP(+) was taken up by the dopamine transporter (DAT). MPP(+) then triggered oxidative stress and caspase activation, as well as ATP-depletion followed by cell death. Enhanced survival of the neurons in the presence of agents interfering with mitochondrial pathology, such as the fission inhibitor Mdivi-1 or a Bax channel blocker suggested a pivotal role of mitochondria in this model. However, these compounds did not prevent cellular ATP-depletion. To further investigate whether cells could be rescued despite respiratory chain inhibition by MPP(+), we have chosen a diverse set of pharmacological inhibitors well-known to interfere with MPP(+) toxicity. The antioxidant ascorbate, the iron chelator desferoxamine, the stress kinase inhibitor CEP1347, and different caspase inhibitors reduced cell death, but allowed ATP-depletion in protected cells. None of these compounds interfered with MPP(+) accumulation in the cells. These findings suggest that ATP-depletion, as the initial mitochondrial effect of MPP(+), requires further downstream processes to result in neuronal death. These processes may form self-enhancing signaling loops, that aggravate an initial energetic impairment and eventually determine cell fate. PMID:22206971

  18. Glycyrrhizin attenuates kainic Acid-induced neuronal cell death in the mouse hippocampus.

    PubMed

    Luo, Lidan; Jin, Yinchuan; Kim, Il-Doo; Lee, Ja-Kyeong

    2013-06-01

    Glycyrrhizin (GL), a triterpene that is present in the roots and rhizomes of licorice (Glycyrrhiza glabra), has been reported to have anti-inflammatory and anti-viral effects. Recently, we demonstrated that GL produced the neuroprotective effects with the suppression of microglia activation and proinflammatory cytokine induction in the postischemic brain with middle cerebral artery occlusion (MCAO) in rats and improved motor impairment and neurological deficits. In the present study, we investigated whether GL has a beneficial effect in kainic acid (KA)-induced neuronal death model. Intracerebroventricular (i.c.v.) injection of 0.94 nmole (0.2 µg) of KA produced typical neuronal death in both CA1 and CA3 regions of the hippocampus. In contrast, administration of GL (10 mg/kg, i.p.) 30 min before KA administration significantly suppressed the neuronal death, and this protective effect was more stronger at 50 mg/kg. Moreover, the GL-mediated neuroprotection was accompanied with the suppression of gliosis and induction of proinflammatory markers (COX-2, iNOS, and TNF-α). The anti-inflammatory and anti-excitotoxic effects of GL were verified in LPS-treated primary microglial cultures and in NMDA- or KA-treated primary cortical cultures. Together these results suggest that GL confers the neuroprotection through the mechanism of anti-inflammatory and anti-excitotoxic effects in KA-treated brain. PMID:23833559

  19. Rescue from Sexually Dimorphic Neuronal Cell Death by Estradiol and PI3 Kinase Activity.

    PubMed

    Cheng, Hui-Yun; Hung, Shin-Hui; Chu, Po-Ju

    2016-07-01

    Responses of primary hippocampal and cortical neurons derived from male and female rats to cellular stressors were studied. It is demonstrated that 17β-estradiol (E2), a potent neuroprotectant, protected the female neurons but had no effects on the male neurons from CoCl2- and glutamate-induced toxicity. Agonists of the estrogen receptor (ER) subtypes ERα and ERβ, DPN and PPT, respectively, had similar effects to E2. By contrast, effects of E2 were abolished by the ER antagonist ICI-182780, further corroborating the neuroprotective role of ERs. In male neurons, CoCl2 predominately activated the apoptosis-inducing factor (AIF)-dependent pathway and AIF translocation from the cytosol to the nucleus. In comparison, CoCl2 activated the caspase pathway and cytochrome c release in female neurons. The inhibitors of these pathways, namely DiQ for AIF and zVAD for caspase, specifically rescued CoCl2-induced cell death in male and female neurons, respectively. When zVAD and ICI-182780, and E2 were applied in combination, it was demonstrated E2 acted on the caspase pathway leading to female-specific neuroprotection. Furthermore, the PI3 kinase (PI3K) inhibitor blocked the rescue effects of DiQ and zVAD on the male and female neurons, respectively, suggesting that PI3K is a common upstream regulator for both pathways. The present study suggested that both sex-specific and nonspecific mechanisms played a role in neuronal responses to stressors and protective reagents. PMID:26369912

  20. A beacon of hope in stroke therapy-Blockade of pathologically activated cellular events in excitotoxic neuronal death as potential neuroprotective strategies.

    PubMed

    Hoque, Ashfaqul; Hossain, M Iqbal; Ameen, S Sadia; Ang, Ching-Seng; Williamson, Nicholas; Ng, Dominic C H; Chueh, Anderly C; Roulston, Carli; Cheng, Heung-Chin

    2016-04-01

    Excitotoxicity, a pathological process caused by over-stimulation of ionotropic glutamate receptors, is a major cause of neuronal loss in acute and chronic neurological conditions such as ischaemic stroke, Alzheimer's and Huntington's diseases. Effective neuroprotective drugs to reduce excitotoxic neuronal loss in patients suffering from these neurological conditions are urgently needed. One avenue to achieve this goal is to clearly define the intracellular events mediating the neurotoxic signals originating from the over-stimulated glutamate receptors in neurons. In this review, we first focus on the key cellular events directing neuronal death but not involved in normal physiological processes in the neurotoxic signalling pathways. These events, referred to as pathologically activated events, are potential targets for the development of neuroprotectant therapeutics. Inhibitors blocking some of the known pathologically activated cellular events have been proven to be effective in reducing stroke-induced brain damage in animal models. Notable examples are inhibitors suppressing the ion channel activity of neurotoxic glutamate receptors and those disrupting interactions of specific cellular proteins occurring only in neurons undergoing excitotoxic cell death. Among them, Tat-NR2B9c and memantine are clinically effective in reducing brain damage caused by some acute and chronic neurological conditions. Our second focus is evaluation of the suitability of the other inhibitors for use as neuroprotective therapeutics. We also discuss the experimental approaches suitable for bridging our knowledge gap in our current understanding of the excitotoxic signalling mechanism in neurons and discovery of new pathologically activated cellular events as potential targets for neuroprotection. PMID:26899498

  1. Uncoupling neuronal death and dysfunction in Drosophila models of neurodegenerative disease.

    PubMed

    Chouhan, Amit K; Guo, Caiwei; Hsieh, Yi-Chen; Ye, Hui; Senturk, Mumine; Zuo, Zhongyuan; Li, Yarong; Chatterjee, Shreyasi; Botas, Juan; Jackson, George R; Bellen, Hugo J; Shulman, Joshua M

    2016-01-01

    Common neurodegenerative proteinopathies, such as Alzheimer's disease (AD) and Parkinson's disease (PD), are characterized by the misfolding and aggregation of toxic protein species, including the amyloid beta (Aß) peptide, microtubule-associated protein Tau (Tau), and alpha-synuclein (αSyn) protein. These factors also show toxicity in Drosophila; however, potential limitations of prior studies include poor discrimination between effects on the adult versus developing nervous system and neuronal versus glial cell types. In addition, variable expression paradigms and outcomes hinder systematic comparison of toxicity profiles. Using standardized conditions and medium-throughput assays, we express human Tau, Aß or αSyn selectively in neurons of the adult Drosophila retina and monitor age-dependent changes in both structure and function, based on tissue histology and recordings of the electroretinogram (ERG), respectively. We find that each protein causes a unique profile of neurodegenerative pathology, demonstrating distinct and separable impacts on neuronal death and dysfunction. Strikingly, expression of Tau leads to progressive loss of ERG responses whereas retinal architecture and neuronal numbers are largely preserved. By contrast, Aß induces modest, age-dependent neuronal loss without degrading the retinal ERG. αSyn expression, using a codon-optimized transgene, is characterized by marked retinal vacuolar change, progressive photoreceptor cell death, and delayed-onset but modest ERG changes. Lastly, to address potential mechanisms, we perform transmission electron microscopy (TEM) to reveal potential degenerative changes at the ultrastructural level. Surprisingly, Tau and αSyn each cause prominent but distinct synaptotoxic profiles, including disorganization or enlargement of photoreceptor terminals, respectively. Our findings highlight variable and dynamic properties of neurodegeneration triggered by these disease-relevant proteins in vivo, and suggest

  2. Neuroprotective effect of Arthrospira (Spirulina) platensis against kainic acid-neuronal death.

    PubMed

    Pérez-Juárez, Angélica; Chamorro, Germán; Alva-Sánchez, Claudia; Paniagua-Castro, Norma; Pacheco-Rosado, Jorge

    2016-08-01

    Context Arthrospira (Spirulina) platensis (SP) is a cyanobacterium which has attracted attention because of its nutritional value and pharmacological properties. It was previously reported that SP reduces oxidative stress in the hippocampus and protects against damaging neurobehavioural effects of systemic kainic acid (KA). It is widely known that the systemic administration of KA induces neuronal damage, specifically in the CA3 hippocampal region. Objective The present study determines if the SP sub-chronic treatment has neuroprotective properties against KA. Materials and methods Male SW mice were treated with SP during 24 d, at doses of 0, 200, and 800 mg/kg, once daily, and with KA (35 mg/kg, ip) as a single dose on day 14. After the treatment, a histological analysis was performed and the number of atrophic neuronal cells in CA3 hippocampal region was quantified. Results Pretreatment with SP does not protect against seizures induced by KA. However, mortality in the SP 200 and the SP 800 groups was of 20%, while for the KA group, it was of 60%. A single KA ip administration produced a considerable neuronal damage, whereas both doses of SP sub-chronic treatment reduced the number of atrophic neurons in CA3 hippocampal region with respect to the KA group. Discussion The SP neurobehaviour improvement after KA systemic administration correlates with the capacity of SP to reduce KA-neuronal death in CA3 hippocampal cells. This neuroprotection may be related to the antioxidant properties of SP. Conclusion SP reduces KA-neuronal death in CA3 hippocampal cells. PMID:26799655

  3. 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

  4. Increased neuronal death and disturbed axonal growth in the Polμ-deficient mouse embryonic retina

    PubMed Central

    Baleriola, Jimena; Álvarez-Lindo, Noemí; de la Villa, Pedro; Bernad, Antonio; Blanco, Luis; Suárez, Teresa; de la Rosa, Enrique J.

    2016-01-01

    Programmed cell death occurs naturally at different stages of neural development, including neurogenesis. The functional role of this early phase of neural cell death, which affects recently differentiated neurons among other cell types, remains undefined. Some mouse models defective in DNA double-strand break (DSB) repair present massive cell death during neural development, occasionally provoking embryonic lethality, while other organs and tissues remain unaffected. This suggests that DSBs occur frequently and selectively in the developing nervous system. We analyzed the embryonic retina of a mouse model deficient in the error-prone DNA polymerase μ (Polμ), a key component of the non-homologous end-joining (NHEJ) repair system. DNA DSBs were increased in the mutant mouse at embryonic day 13.5 (E13.5), as well as the incidence of cell death that affected young neurons, including retinal ganglion cells (RGCs). Polμ−/− mice also showed disturbed RGC axonal growth and navigation, and altered distribution of the axonal guidance molecules L1-CAM and Bravo (also known as Nr-CAM). These findings demonstrate that Polμ is necessary for proper retinal development, and support that the generation of DSBs and their repair via the NHEJ pathway are genuine processes involved in neural development. PMID:27172884

  5. Increased neuronal death and disturbed axonal growth in the Polμ-deficient mouse embryonic retina.

    PubMed

    Baleriola, Jimena; Álvarez-Lindo, Noemí; de la Villa, Pedro; Bernad, Antonio; Blanco, Luis; Suárez, Teresa; de la Rosa, Enrique J

    2016-01-01

    Programmed cell death occurs naturally at different stages of neural development, including neurogenesis. The functional role of this early phase of neural cell death, which affects recently differentiated neurons among other cell types, remains undefined. Some mouse models defective in DNA double-strand break (DSB) repair present massive cell death during neural development, occasionally provoking embryonic lethality, while other organs and tissues remain unaffected. This suggests that DSBs occur frequently and selectively in the developing nervous system. We analyzed the embryonic retina of a mouse model deficient in the error-prone DNA polymerase μ (Polμ), a key component of the non-homologous end-joining (NHEJ) repair system. DNA DSBs were increased in the mutant mouse at embryonic day 13.5 (E13.5), as well as the incidence of cell death that affected young neurons, including retinal ganglion cells (RGCs). Polμ(-/-) mice also showed disturbed RGC axonal growth and navigation, and altered distribution of the axonal guidance molecules L1-CAM and Bravo (also known as Nr-CAM). These findings demonstrate that Polμ is necessary for proper retinal development, and support that the generation of DSBs and their repair via the NHEJ pathway are genuine processes involved in neural development. PMID:27172884

  6. miR-711 upregulation induces neuronal cell death after traumatic brain injury.

    PubMed

    Sabirzhanov, B; Stoica, B A; Zhao, Z; Loane, D J; Wu, J; Dorsey, S G; Faden, A I

    2016-04-01

    Traumatic brain injury (TBI) is a leading cause of mortality and disability. MicroRNAs (miRs) are small noncoding RNAs that negatively regulate gene expression at post-transcriptional level and may be key modulators of neuronal apoptosis, yet their role in secondary injury after TBI remains largely unexplored. Changes in miRs after controlled cortical impact (CCI) in mice were examined during the first 72 h using miR arrays and qPCR. One selected miR (711) was examined with regard to its regulation and relation to cell death; effects of miR-711 modulation were evaluated after CCI and using in vitro cell death models of primary cortical neurons. Levels of miR-711 were increased in the cortex early after TBI and in vitro models through rapid upregulation of miR-711 transcription (pri-miR-711) rather than catabolism. Increases coincided with downregulation of the pro-survival protein Akt, a predicted target of miR-711, with sequential activation of forkhead box O3 (FoxO3)a/glycogen synthase kinase 3 (GSK3)α/β, pro-apoptotic BH3-only molecules PUMA (Bcl2-binding component 3) and Bim (Bcl2-like 11 (apoptosis facilitator)), and mitochondrial release of cytochrome c and AIF. miR-711 and Akt (mRNA) co-immunoprecipitated with the RNA-induced silencing complex (RISC). A miR-711 hairpin inhibitor attenuated the apoptotic mechanisms and decreased neuronal death in an Akt-dependent manner. Conversely, a miR-711 mimic enhanced neuronal apoptosis. Central administration of the miR-711 hairpin inhibitor after TBI increased Akt expression and attenuated apoptotic pathways. Treatment reduced cortical lesion volume, neuronal cell loss in cortex and hippocampus, and long-term neurological dysfunction. miR-711 changes contribute to neuronal cell death after TBI, in part by inhibiting Akt, and may serve as a novel therapeutic target. PMID:26470728

  7. Antihelminthic Benzimidazoles Are Novel HIF Activators That Prevent Oxidative Neuronal Death via Binding to Tubulin

    PubMed Central

    Aleyasin, Hossein; Karuppagounder, Saravanan S.; Kumar, Amit; Sleiman, Sama; Basso, Manuela; Ma, Thong; Siddiq, Ambreena; Chinta, Shankar J.; Brochier, Camille; Langley, Brett; Haskew-Layton, Renee; Bane, Susan L.; Riggins, Gregory J.; Gazaryan, Irina; Starkov, Anatoly A.; Andersen, Julie K.

    2015-01-01

    Abstract Aims: Pharmacological activation of the adaptive response to hypoxia is a therapeutic strategy of growing interest for neurological conditions, including stroke, Huntington's disease, and Parkinson's disease. We screened a drug library with known safety in humans using a hippocampal neuroblast line expressing a reporter of hypoxia-inducible factor (HIF)-dependent transcription. Results: Our screen identified more than 40 compounds with the ability to induce hypoxia response element-driven luciferase activity as well or better than deferoxamine, a canonical activator of hypoxic adaptation. Among the chemical entities identified, the antihelminthic benzimidazoles represented one pharmacophore that appeared multiple times in our screen. Secondary assays confirmed that antihelminthics stabilized the transcriptional activator HIF-1α and induced expression of a known HIF target gene, p21cip1/waf1, in post-mitotic cortical neurons. The on-target effect of these agents in stimulating hypoxic signaling was binding to free tubulin. Moreover, antihelminthic benzimidazoles also abrogated oxidative stress-induced death in vitro, and this on-target effect also involves binding to free tubulin. Innovation and Conclusions: These studies demonstrate that tubulin-binding drugs can activate a component of the hypoxic adaptive response, specifically the stabilization of HIF-1α and its downstream targets. Tubulin-binding drugs, including antihelminthic benzimidazoles, also abrogate oxidative neuronal death in primary neurons. Given their safety in humans and known ability to penetrate into the central nervous system, antihelminthic benzimidazoles may be considered viable candidates for treating diseases associated with oxidative neuronal death, including stroke. Antioxid. Redox Signal. 22, 121–134. PMID:24766300

  8. Histone Hyperacetylation Up-regulates Protein Kinase Cδ in Dopaminergic Neurons to Induce Cell Death

    PubMed Central

    Jin, Huajun; Kanthasamy, Arthi; Harischandra, Dilshan S.; Kondru, Naveen; Ghosh, Anamitra; Panicker, Nikhil; Anantharam, Vellareddy; Rana, Ajay; Kanthasamy, Anumantha G.

    2014-01-01

    The oxidative stress-sensitive protein kinase Cδ (PKCδ) has been implicated in dopaminergic neuronal cell death. However, little is known about the epigenetic mechanisms regulating PKCδ expression in neurons. Here, we report a novel mechanism by which the PKCδ gene can be regulated by histone acetylation. Treatment with histone deacetylase (HDAC) inhibitor sodium butyrate (NaBu) induced PKCδ expression in cultured neurons, brain slices, and animal models. Several other HDAC inhibitors also mimicked NaBu. The chromatin immunoprecipitation analysis revealed that hyperacetylation of histone H4 by NaBu is associated with the PKCδ promoter. Deletion analysis of the PKCδ promoter mapped the NaBu-responsive element to an 81-bp minimal promoter region. Detailed mutagenesis studies within this region revealed that four GC boxes conferred hyperacetylation-induced PKCδ promoter activation. Cotransfection experiments and Sp inhibitor studies demonstrated that Sp1, Sp3, and Sp4 regulated NaBu-induced PKCδ up-regulation. However, NaBu did not alter the DNA binding activities of Sp proteins or their expression. Interestingly, a one-hybrid analysis revealed that NaBu enhanced transcriptional activity of Sp1/Sp3. Overexpression of the p300/cAMP-response element-binding protein-binding protein (CBP) potentiated the NaBu-mediated transactivation potential of Sp1/Sp3, but expressing several HDACs attenuated this effect, suggesting that p300/CBP and HDACs act as coactivators or corepressors in histone acetylation-induced PKCδ up-regulation. Finally, using genetic and pharmacological approaches, we showed that NaBu up-regulation of PKCδ sensitizes neurons to cell death in a human dopaminergic cell model and brain slice cultures. Together, these results indicate that histone acetylation regulates PKCδ expression to augment nigrostriatal dopaminergic cell death, which could contribute to the progressive neuropathogenesis of Parkinson disease. PMID:25342743

  9. Cabergoline, Dopamine D2 Receptor Agonist, Prevents Neuronal Cell Death under Oxidative Stress via Reducing Excitotoxicity

    PubMed Central

    Odaka, Haruki; Numakawa, Tadahiro; Adachi, Naoki; Ooshima, Yoshiko; Nakajima, Shingo; Katanuma, Yusuke; Inoue, Takafumi; Kunugi, Hiroshi

    2014-01-01

    Several lines of evidence demonstrate that oxidative stress is involved in the pathogenesis of neurodegenerative diseases, including Parkinson's disease. Potent antioxidants may therefore be effective in the treatment of such diseases. Cabergoline, a dopamine D2 receptor agonist and antiparkinson drug, has been studied using several cell types including mesencephalic neurons, and is recognized as a potent radical scavenger. Here, we examined whether cabergoline exerts neuroprotective effects against oxidative stress through a receptor-mediated mechanism in cultured cortical neurons. We found that neuronal death induced by H2O2 exposure was inhibited by pretreatment with cabergoline, while this protective effect was eliminated in the presence of a dopamine D2 receptor inhibitor, spiperone. Activation of ERK1/2 by H2O2 was suppressed by cabergoline, and an ERK signaling pathway inhibitor, U0126, similarly protected cortical neurons from cell death. This suggested the ERK signaling pathway has a critical role in cabergoline-mediated neuroprotection. Furthermore, increased extracellular levels of glutamate induced by H2O2, which might contribute to ERK activation, were reduced by cabergoline, while inhibitors for NMDA receptor or L-type Ca2+ channel demonstrated a survival effect against H2O2. Interestingly, we found that cabergoline increased expression levels of glutamate transporters such as EAAC1. Taken together, these results suggest that cabergoline has a protective effect on cortical neurons via a receptor-mediated mechanism including repression of ERK1/2 activation and extracellular glutamate accumulation induced by H2O2. PMID:24914776

  10. Effects of Alda-1, an Aldehyde Dehydrogenase-2 Agonist, on Hypoglycemic Neuronal Death

    PubMed Central

    Ikeda, Tetsuhiko; Takahashi, Tetsuya; Tsujita, Mika; Kanazawa, Masato; Toriyabe, Masafumi; Koyama, Misaki; Itoh, Kosuke; Nakada, Tsutomu; Nishizawa, Masatoyo; Shimohata, Takayoshi

    2015-01-01

    Hypoglycemic encephalopathy (HE) is caused by a lack of glucose availability to neuronal cells, and no neuroprotective drugs have been developed as yet. Studies on the pathogenesis of HE and the development of new neuroprotective drugs have been conducted using animal models such as the hypoglycemic coma model and non-coma hypoglycemia model. However, both models have inherent problems, and establishment of animal models that mimic clinical situations is desirable. In this study, we first developed a short-term hypoglycemic coma model in which rats could be maintained in an isoelectric electroencephalogram (EEG) state for 2 min and subsequent hyperglycemia without requiring anti-seizure drugs and an artificial ventilation. This condition caused the production of 4-hydroxy-2-nonenal (4-HNE), a cytotoxic aldehyde, in neurons of the hippocampus and cerebral cortex, and a marked increase in neuronal death as evaluated by Fluoro-Jade B (FJB) staining. We also investigated whether N-(1,3-benzodioxole-5-ylmethyl)-2,6-dichlorobenzamide (Alda-1), a small-molecule agonist of aldehyde dehydrogenase-2, could attenuate 4-HNE levels and reduce hypoglycemic neuronal death. After confirming that EEG recordings remained isoelectric for 2 min, Alda-1 (8.5 mg/kg) or vehicle (dimethyl sulfoxide; DMSO) was administered intravenously with glucose to maintain a blood glucose level of 250 to 270 mg/dL. Fewer 4-HNE and FJB-positive cells were observed in the cerebral cortex of Alda-1-treated rats than in DMSO-treated rats 24 h after glucose administration (P = 0.002 and P = 0.020). Thus, activation of the ALDH2 pathway could be a molecular target for HE treatment, and Alda-1 is a potentially neuroprotective agent that exerts a beneficial effect on neurons when intravenously administered simultaneously with glucose. PMID:26083658

  11. Developmental mercury exposure elicits acute hippocampal cell death, reductions in neurogenesis, and severe learning deficits during puberty.

    PubMed

    Falluel-Morel, Anthony; Sokolowski, Katie; Sisti, Helene M; Zhou, Xiaofeng; Shors, Tracey J; Dicicco-Bloom, Emanuel

    2007-12-01

    Normal brain development requires coordinated regulation of several processes including proliferation, differentiation, and cell death. Multiple factors from endogenous and exogenous sources interact to elicit positive as well as negative regulation of these processes. In particular, the perinatal rat brain is highly vulnerable to specific developmental insults that produce later cognitive abnormalities. We used this model to examine the developmental effects of an exogenous factor of great concern, methylmercury (MeHg). Seven-day-old rats received a single injection of MeHg (5 microg/gbw). MeHg inhibited DNA synthesis by 44% and reduced levels of cyclins D1, D3, and E at 24 h in the hippocampus, but not the cerebellum. Toxicity was associated acutely with caspase-dependent programmed cell death. MeHg exposure led to reductions in hippocampal size (21%) and cell numbers 2 weeks later, especially in the granule cell layer (16%) and hilus (50%) of the dentate gyrus defined stereologically, suggesting that neurons might be particularly vulnerable. Consistent with this, perinatal exposure led to profound deficits in juvenile hippocampal-dependent learning during training on a spatial navigation task. In aggregate, these studies indicate that exposure to one dose of MeHg during the perinatal period acutely induces apoptotic cell death, which results in later deficits in hippocampal structure and function. PMID:17760861

  12. Hypertriglyceridemia-induced acute pancreatitis in pregnancy causing maternal death

    PubMed Central

    Jeon, Hae Rin; Cho, Yoon Jin; Chon, Seung Joo

    2016-01-01

    Acute pancreatitis in pregnancy is rare and occurs in approximately 3 in 10,000 pregnancies. It rarely complicates pregnancy, and can occur during any trimester, however over half (52%) of cases occur during the third trimester and during the post-partum period. Gallstones are the most common cause of acute pancreatitis. On the other hand, acute pancreatitis caused by hypertriglyceridemia due to increase of estrogen during the gestational period is very unusual, but complication carries a higher risk of morbidity and mortality for both the mother and the fetus. We experienced a case of pregnant woman who died of acute exacerbation of hypertriglyceridemia-induced acute pancreatitis at 23 weeks of gestation. We report on progress and management of this case along with literature reviews. PMID:27004207

  13. 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

  14. Gephyrin Cleavage in In Vitro Brain Ischemia Decreases GABAA Receptor Clustering and Contributes to Neuronal Death.

    PubMed

    Costa, João T; Mele, Miranda; Baptista, Márcio S; Gomes, João R; Ruscher, Karsten; Nobre, Rui J; de Almeida, Luís Pereira; Wieloch, Tadeusz; Duarte, Carlos B

    2016-08-01

    GABA (γ-aminobutyric acid) is the major inhibitory neurotransmitter in the central nervous system, and changes in GABAergic neurotransmission modulate the activity of neuronal networks. Gephyrin is a scaffold protein responsible for the traffic and synaptic anchoring of GABAA receptors (GABAAR); therefore, changes in gephyrin expression and oligomerization may affect the activity of GABAergic synapses. In this work, we investigated the changes in gephyrin protein levels during brain ischemia and in excitotoxic conditions, which may affect synaptic clustering of GABAAR. We found that gephyrin is cleaved by calpains following excitotoxic stimulation of hippocampal neurons with glutamate, as well as after intrahippocampal injection of kainate, giving rise to a stable cleavage product. Gephyrin cleavage was also observed in cultured hippocampal neurons subjected to transient oxygen-glucose deprivation (OGD), an in vitro model of brain ischemia, and after transient middle cerebral artery occlusion (MCAO) in mice, a model of focal brain ischemia. Furthermore, a truncated form of gephyrin decreased the synaptic clustering of the protein, reduced the synaptic pool of GABAAR containing γ2 subunits and upregulated OGD-induced cell death in hippocampal cultures. Our results show that excitotoxicity and brain ischemia downregulate full-length gephyrin with a concomitant generation of truncated products, which affect synaptic clustering of GABAAR and cell death. PMID:26093381

  15. Chronic stress enhances microglia activation and exacerbates death of nigral dopaminergic neurons under conditions of inflammation

    PubMed Central

    2014-01-01

    Background Parkinson’s disease is an irreversible neurodegenerative disease linked to progressive movement disorders and is accompanied by an inflammatory reaction that is believed to contribute to its pathogenesis. Since sensitivity to inflammation is not the same in all brain structures, the aim of this work was to test whether physiological conditions as stress could enhance susceptibility to inflammation in the substantia nigra, where death of dopaminergic neurons takes place in Parkinson’s disease. Methods To achieve our aim, we induced an inflammatory process in nonstressed and stressed rats (subject to a chronic variate stress) by a single intranigral injection of lipopolysaccharide, a potent proinflammogen. The effect of this treatment was evaluated on inflammatory markers as well as on neuronal and glial populations. Results Data showed a synergistic effect between inflammation and stress, thus resulting in higher microglial activation and expression of proinflammatory markers. More important, the higher inflammatory response seen in stressed animals was associated with a higher rate of death of dopaminergic neurons in the substantia nigra, the most characteristic feature seen in Parkinson’s disease. This effect was dependent on glucocorticoids. Conclusions Our data demonstrate that stress sensitises midbrain microglia to further inflammatory stimulus. This suggests that stress may be an important risk factor in the degenerative processes and symptoms of Parkinson’s disease. PMID:24565378

  16. 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

  17. Dendritic regression dissociated from neuronal death but associated with partial deafferentation in aging rat supraoptic nucleus.

    PubMed

    Flood, D G; Coleman, P D

    1993-01-01

    As neurons are lost in normal aging, the dendrites of surviving neighbor neurons may proliferate, regress, or remain unchanged. In the case of age-related dendritic regression, it has been difficult to distinguish whether the regression precedes neuronal death or whether it is a consequence of loss of afferent supply. The rat supraoptic nucleus (SON) represents a model system in which there is no age-related loss of neurons, but in which there is an age-related loss of afferents. The magnocellular neurosecretory neurons of the SON, that produce vasopressin and oxytocin for release in the posterior pituitary, were studied in male Fischer 344 rats at 3, 12, 20, 27, 30, and 32 months of age. Counts in Nissl-stained sections showed no neuronal loss with age, and confirmed similar findings in other strains of rat and in mouse and human. Nucleolar size increased between 3 and 12 months of age, due, in part, to nucleolar fusion, and was unchanged between 12 and 32 months of age, indicating maintenance of general cellular function in old age. Dendritic extent quantified in Golgi-stained tissue increased between 3 and 12 months of age, was stable between 12 and 20 months, and decreased between 20 and 27 months. We interpret the increase between 3 and 12 months as a late maturational change. Dendritic regression between 20 and 27 months was probably the result of deafferentation due to the preceding age-related loss of the noradrenergic input to the SON from the ventral medulla. PMID:7507575

  18. The anti-hypertensive drug reserpine induces neuronal cell death through inhibition of autophagic flux.

    PubMed

    Lee, Kang Il; Kim, Min Ju; Koh, Hyongjong; Lee, Jin I; Namkoong, Sim; Oh, Won Keun; Park, Junsoo

    2015-07-10

    Reserpine is a well-known medicine for the treatment of hypertension and schizophrenia, but its administration can induce Parkinson's disease (PD)-like symptoms in humans and animals. Reserpine inhibits the vesicular transporter of monoamines and depletes the brain of monoamines such as dopamine. However, the cellular function of reserpine is not fully understood. In this report, we present one possible mechanism by which reserpine may contribute to PD-like symptoms. Reserpine treatment induced the formation of enlarged autophagosomes by inhibiting the autophagic flux and led to accumulation of p62, an autophagy adapter molecule. In particular, reserpine treatment increased the level of α-synuclein protein and led to accumulation of α-synuclein in autophagosomes. Treatment with rapamycin enhanced the effect of reserpine by further increasing the level of α-synuclein and neuronal cell death. Drosophila raised on media containing reserpine showed loss of dopaminergic neurons. Furthermore, cotreatment with reserpine and rapamycin aggravated the loss of dopaminergic neurons. Our results suggest that reserpine contributes to the loss of dopaminergic neurons by interfering with autophagic flux. PMID:25976674

  19. Oleuropein Prevents Neuronal Death, Mitigates Mitochondrial Superoxide Production and Modulates Autophagy in a Dopaminergic Cellular Model

    PubMed Central

    Achour, Imène; Arel-Dubeau, Anne-Marie; Renaud, Justine; Legrand, Manon; Attard, Everaldo; Germain, Marc; Martinoli, Maria-Grazia

    2016-01-01

    Parkinson’s disease (PD) is a progressive neurodegenerative disorder, primarily affecting dopaminergic neurons in the substantia nigra. There is currently no cure for PD and present medications aim to alleviate clinical symptoms, thus prevention remains the ideal strategy to reduce the prevalence of this disease. The goal of this study was to investigate whether oleuropein (OLE), the major phenolic compound in olive derivatives, may prevent neuronal degeneration in a cellular dopaminergic model of PD, differentiated PC12 cells exposed to the potent parkinsonian toxin 6-hydroxydopamine (6-OHDA). We also investigated OLE’s ability to mitigate mitochondrial oxidative stress and modulate the autophagic flux. Our results obtained by measuring cytotoxicity and apoptotic events demonstrate that OLE significantly decreases neuronal death. OLE could also reduce mitochondrial production of reactive oxygen species resulting from blocking superoxide dismutase activity. Moreover, quantification of autophagic and acidic vesicles in the cytoplasm alongside expression of specific autophagic markers uncovered a regulatory role for OLE against autophagic flux impairment induced by bafilomycin A1. Altogether, our results define OLE as a neuroprotective, anti-oxidative and autophagy-regulating molecule, in a neuronal dopaminergic cellular model. PMID:27517912

  20. Receptor interacting protein 140 attenuates endoplasmic reticulum stress in neurons and protects against cell death

    PubMed Central

    Feng, Xudong; Krogh, Kelly A.; Wu, Cheng-Ying; Lin, Yi-Wei; Tsai, Hong-Chieh; Thayer, Stanley A.; Wei, Li-Na

    2014-01-01

    Inositol 1, 4, 5-trisphosphate receptor (IP3R)-mediated Ca2+ release from the endoplasmic reticulum (ER) triggers many physiological responses in neurons and when uncontrolled can cause ER stress that contributes to neurological disease. Here we show that the unfolded protein response (UPR) in neurons induces rapid translocation of nuclear receptor-interacting protein 140 (RIP140) to the cytoplasm. In the cytoplasm, RIP140 localizes to the ER by binding to the IP3R. The carboxyl-terminal RD4 domain of RIP140 interacts with the carboxyl-terminal gate-keeping domain of the IP3R. This molecular interaction disrupts the IP3R's “head-tail” interaction, thereby suppressing channel opening and attenuating IP3R-mediated Ca2+ release. This contributes to a rapid suppression of the ER stress response and provides protection from apoptosis in both hippocampal neurons in vitro and in an animal model of ER stress. Thus, RIP140 translocation to the cytoplasm is an early response to ER stress and provides protection against neuronal death. PMID:25066731

  1. Oleuropein Prevents Neuronal Death, Mitigates Mitochondrial Superoxide Production and Modulates Autophagy in a Dopaminergic Cellular Model.

    PubMed

    Achour, Imène; Arel-Dubeau, Anne-Marie; Renaud, Justine; Legrand, Manon; Attard, Everaldo; Germain, Marc; Martinoli, Maria-Grazia

    2016-01-01

    Parkinson's disease (PD) is a progressive neurodegenerative disorder, primarily affecting dopaminergic neurons in the substantia nigra. There is currently no cure for PD and present medications aim to alleviate clinical symptoms, thus prevention remains the ideal strategy to reduce the prevalence of this disease. The goal of this study was to investigate whether oleuropein (OLE), the major phenolic compound in olive derivatives, may prevent neuronal degeneration in a cellular dopaminergic model of PD, differentiated PC12 cells exposed to the potent parkinsonian toxin 6-hydroxydopamine (6-OHDA). We also investigated OLE's ability to mitigate mitochondrial oxidative stress and modulate the autophagic flux. Our results obtained by measuring cytotoxicity and apoptotic events demonstrate that OLE significantly decreases neuronal death. OLE could also reduce mitochondrial production of reactive oxygen species resulting from blocking superoxide dismutase activity. Moreover, quantification of autophagic and acidic vesicles in the cytoplasm alongside expression of specific autophagic markers uncovered a regulatory role for OLE against autophagic flux impairment induced by bafilomycin A1. Altogether, our results define OLE as a neuroprotective, anti-oxidative and autophagy-regulating molecule, in a neuronal dopaminergic cellular model. PMID:27517912

  2. 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

  3. The Cell Death Pathway Regulates Synapse Elimination through Cleavage of Gelsolin in Caenorhabditis elegans Neurons.

    PubMed

    Meng, Lingfeng; Mulcahy, Ben; Cook, Steven J; Neubauer, Marianna; Wan, Airong; Jin, Yishi; Yan, Dong

    2015-06-23

    Synapse elimination occurs in development, plasticity, and disease. Although the importance of synapse elimination has been documented in many studies, the molecular mechanisms underlying this process are unclear. Here, using the development of C. elegans RME neurons as a model, we have uncovered a function for the apoptosis pathway in synapse elimination. We find that the conserved apoptotic cell death (CED) pathway and axonal mitochondria are required for the elimination of transiently formed clusters of presynaptic components in RME neurons. This function of the CED pathway involves the activation of the actin-filament-severing protein, GSNL-1. Furthermore, we show that caspase CED-3 cleaves GSNL-1 at a conserved C-terminal region and that the cleaved active form of GSNL-1 promotes its actin-severing ability. Our data suggest that activation of the CED pathway contributes to selective elimination of synapses through disassembly of the actin filament network. PMID:26074078

  4. 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

  5. Phosphorylation of CHIP at Ser20 by Cdk5 promotes tAIF-mediated neuronal death.

    PubMed

    Kim, C; Yun, N; Lee, J; Youdim, M B H; Ju, C; Kim, W-K; Han, P-L; Oh, Y J

    2016-02-01

    Cyclin-dependent kinase 5 (Cdk5) is a proline-directed serine/threonine kinase and its dysregulation is implicated in neurodegenerative diseases. Likewise, C-terminus of Hsc70-interacting protein (CHIP) is linked to neurological disorders, serving as an E3 ubiquitin ligase for targeting damaged or toxic proteins for proteasomal degradation. Here, we demonstrate that CHIP is a novel substrate for Cdk5. Cdk5 phosphorylates CHIP at Ser20 via direct binding to a highly charged domain of CHIP. Co-immunoprecipitation and ubiquitination assays reveal that Cdk5-mediated phosphorylation disrupts the interaction between CHIP and truncated apoptosis-inducing factor (tAIF) without affecting CHIP's E3 ligase activity, resulting in the inhibition of CHIP-mediated degradation of tAIF. Lentiviral transduction assay shows that knockdown of Cdk5 or overexpression of CHIP(S20A), but not CHIP(WT), attenuates tAIF-mediated neuronal cell death induced by hydrogen peroxide. Thus, we conclude that Cdk5-mediated phosphorylation of CHIP negatively regulates its neuroprotective function, thereby contributing to neuronal cell death progression following neurotoxic stimuli. PMID:26206088

  6. Lysosomes and α-synuclein form a dangerous duet leading to neuronal cell death

    PubMed Central

    Bourdenx, Mathieu; Bezard, Erwan; Dehay, Benjamin

    2014-01-01

    Neurodegenerative diseases are (i) characterized by a selective neuronal vulnerability to degeneration in specific brain regions; and (ii) likely to be caused by disease-specific protein misfolding. Parkinson’s disease (PD) is characterized by the presence of intraneuronal proteinacious cytoplasmic inclusions, called Lewy Bodies (LB). α-Synuclein, an aggregation prone protein, has been identified as a major protein component of LB and the causative for autosomal dominant PD. Lysosomes are responsible for the clearance of long-lived proteins, such as α-synuclein, and for the removal of old or damaged organelles, such as mitochondria. Interestingly, PD-linked α-synuclein mutants and dopamine-modified wild-type α-synuclein block its own degradation, which result in insufficient clearance, leading to its aggregation and cell toxicity. Moreover, both lysosomes and lysosomal proteases have been found to be involved in the activation of certain cell death pathways. Interestingly, lysosomal alterations are observed in the brains of patients suffering from sporadic PD and also in toxic and genetic rodent models of PD-related neurodegeneration. All these events have unraveled a causal link between lysosomal impairment, α-synuclein accumulation, and neurotoxicity. In this review, we emphasize the pathophysiological mechanisms connecting α-synuclein and lysosomal dysfunction in neuronal cell death. PMID:25177278

  7. TRPV1 stimulation triggers apoptotic cell death of rat cortical neurons

    SciTech Connect

    Shirakawa, Hisashi; Yamaoka, Tomoko; Sanpei, Kazuaki; Sasaoka, Hirotoshi; Nakagawa, Takayuki; Kaneko, Shuji

    2008-12-26

    Transient receptor potential vanilloid 1 (TRPV1) functions as a polymodal nociceptor and is activated by several vanilloids, including capsaicin, protons and heat. Although TRPV1 channels are widely distributed in the brain, their roles remain unclear. Here, we investigated the roles of TRPV1 in cytotoxic processes using TRPV1-expressing cultured rat cortical neurons. Capsaicin induced severe neuronal death with apoptotic features, which was completely inhibited by the TRPV1 antagonist capsazepine and was dependent on extracellular Ca{sup 2+} influx. Interestingly, nifedipine, a specific L-type Ca{sup 2+} channel blocker, attenuated capsaicin cytotoxicity, even when applied 2-4 h after the capsaicin. ERK inhibitor PD98059 and several antioxidants, but not the JNK and p38 inhibitors, attenuated capsaicin cytotoxicity. Together, these data indicate that TRPV1 activation triggers apoptotic cell death of rat cortical cultures via L-type Ca{sup 2+} channel opening, Ca{sup 2+} influx, ERK phosphorylation, and reactive oxygen species production.

  8. Sigma-1 receptor deficiency reduces MPTP-induced parkinsonism and death of dopaminergic neurons

    PubMed Central

    Hong, J; Sha, S; Zhou, L; Wang, C; Yin, J; Chen, L

    2015-01-01

    Sigma-1 receptor (σ1R) has been reported to be decreased in nigrostriatal motor system of Parkinson's disease patients. Using heterozygous and homozygous σ1R knockout (σ1R+/− and σ1R−/−) mice, we investigated the influence of σ1R deficiency on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-impaired nigrostriatal motor system. The injection of MPTP for 5 weeks in wild-type mice (MPTP-WT mice), but not in σ1R+/− or σ1R−/− mice (MPTP-σ1R+/− or MPTP-σ1R−/− mice), caused motor deficits and ~40% death of dopaminergic neurons in substantia nigra pars compacta with an elevation of N-methyl-d-aspartate receptor (NMDAr) NR2B phosphorylation. The σ1R antagonist NE100 or the NR2B inhibitor Ro25-6981 could alleviate the motor deficits and the death of dopaminergic neurons in MPTP-WT mice. By contrast, MPTP-σ1R+/− mice treated with the σ1R agonist PRE084 or MPTP-σ1R−/− mice treated with the NMDAr agonist NMDA appeared to have similar motor deficits and loss of dopaminergic neurons as MPTP-WT mice. The pharmacological or genetic inactivation of σ1R suppressed the expression of dopamine transporter (DAT) in substantia nigra, which was corrected by NMDA. The activation of σ1R by PRE084 enhanced the DAT expression in WT mice or σ1R+/− mice. By contrast, the level of vesicular monoamine transporter 2 (VMAT2) in σ1R+/− mice or σ1R−/− mice had no difference from WT mice. Interestingly, MPTP-WT mice showed the reduction in the levels of DAT and VMAT2, but MPTP-σ1R−/− mice did not. The inactivation of σ1R by NE100 could prevent the reduction of VMAT2 in MPTP-WT mice. In addition, the activation of microglia cells in substantia nigra was equally enhanced in MPTP-WT mice and MPTP-σ1R−/− mice. The number of activated astrocytes in MPTP-σ1R−/− mice was less than that in MPTP-WT mice. The findings indicate that the σ1R deficiency through suppressing NMDAr function and DAT expression can reduce MPTP-induced death of

  9. PINK1 positively regulates HDAC3 to suppress dopaminergic neuronal cell death.

    PubMed

    Choi, Hyo-Kyoung; Choi, Youngsok; Kang, HeeBum; Lim, Eun-Jin; Park, Soo-Yeon; Lee, Hyun-Seob; Park, Ji-Min; Moon, Jisook; Kim, Yoon-Jung; Choi, Insup; Joe, Eun-Hye; Choi, Kyung-Chul; Yoon, Ho-Geun

    2015-02-15

    Deciphering the molecular basis of neuronal cell death is a central issue in the etiology of neurodegenerative diseases, such as Parkinson's and Alzheimer's. Dysregulation of p53 levels has been implicated in neuronal apoptosis. The role of histone deacetylase 3 (HDAC3) in suppressing p53-dependent apoptosis has been recently emphasized; however, the molecular basis of modulation of p53 function by HDAC3 remains unclear. Here we show that PTEN-induced putative kinase 1 (PINK1), which is linked to autosomal recessive early-onset familial Parkinson's disease, phosphorylates HDAC3 at Ser-424 to enhance its HDAC activity in a neural cell-specific manner. PINK1 prevents H2O2-induced C-terminal cleavage of HDAC3 via phosphorylation of HDAC3 at Ser-424, which is reversed by protein phosphatase 4c. PINK1-mediated phosphorylation of HDAC3 enhances its direct association with p53 and causes subsequent hypoacetylation of p53. Genetic deletion of PINK1 partly impaired the suppressive role of HDAC3 in regulating p53 acetylation and transcriptional activity. However, depletion of HDAC3 fully abolished the PINK1-mediated p53 inhibitory loop. Finally, ectopic expression of phosphomometic-HDAC3(S424E) substantially overcomes the defective action of PINK1 against oxidative stress in dopaminergic neuronal cells. Together, our results uncovered a mechanism by which PINK1-HDAC3 network mediates p53 inhibitory loop in response to oxidative stress-induced damage. PMID:25305081

  10. Treatment with harmine ameliorates functional impairment and neuronal death following traumatic brain injury

    PubMed Central

    ZHONG, ZEQI; TAO, YUAN; YANG, HUI

    2015-01-01

    Traumatic brain injury (TBI) is a leading cause of mortality in young individuals, and results in motor and cognitive deficiency. Excitotoxicity is an important process during neuronal cell death, which is caused by excessive release of glutamate following TBI. Astrocytic glutamate transporters have a predominant role in maintaining extracellular glutamate concentrations below excitotoxic levels, and glutamate transporter 1 (GLT-1) may account for >90% of glutamate uptake in the brain. The β-carboline alkaloid harmine has been demonstrated to exert neuroprotective actions in vivo, and the beneficial effects were specifically due to elevation of GLT-1. However, whether harmine provides neuroprotection following TBI remains to be elucidated. The present study performed intraperitoneal harmine injections in rats (30 mg/kg per day for up to 5 days), in order to investigate whether harmine treatment attenuates brain edema and improves functional recovery in a rat model of TBI. The neuronal survival ratio and the protein expression of apoptosis-associated caspase 3 were also assessed in the hippocampus of the rat brain. Furthermore, the expression levels of GLT-1 and inflammatory cytokines were detected, in order to determine the underlying mechanisms. The results of the present study demonstrated that administration of harmine significantly attenuated cerebral edema, and improved learning and memory ability. In addition, harmine significantly increased the protein expression of GLT-1, and markedly attenuated the expression levels of interleukin-1β and tumor necrosis factor-α, thereby attenuating apoptotic neuronal death in the hippocampus. These results provided in vivo evidence that harmine may exert neuroprotective effects by synergistically reducing excitotoxicity and inflammation following TBI. PMID:26496827

  11. Nicotinamide mononucleotide protects against β-amyloid oligomer-induced cognitive impairment and neuronal death.

    PubMed

    Wang, Xiaonan; Hu, Xuejun; Yang, Yang; Takata, Toshihiro; Sakurai, Takashi

    2016-07-15

    Amyloid-β (Aβ) oligomers are recognized as the primary neurotoxic agents in Alzheimer's disease (AD). Impaired brain energy metabolism and oxidative stress are implicated in cognitive decline in AD. Nicotinamide adenine dinucleotide (NAD(+)), a coenzyme involved in redox activities in the mitochondrial electron transport chain, has been identified as a key regulator of the lifespan-extending effects, and the activation of NAD(+) expression has been linked with a decrease in Aβ toxicity in AD. One of the key precursors of NAD(+) is nicotinamide mononucleotide (NMN), a product of the nicotinamide phosphoribosyltransferase reaction. To determine whether improving brain energy metabolism will forestall disease progress in AD, the impact of the NAD(+) precursor NMN on Aβ oligomer-induced neuronal death and cognitive impairment were studied in organotypic hippocampal slice cultures (OHCs) and in a rat model of AD. Treatment of intracerebroventricular Aβ oligomer infusion AD model rats with NMN (500mg/kg, intraperitoneally) sustained improvement in cognitive function as assessed by the Morris water maze. In OHCs, Aβ oligomer-treated culture media with NMN attenuated neuronal cell death. NMN treatment also significantly prevented the Aβ oligomer-induced inhibition of LTP. Furthermore, NMN restored levels of NAD(+) and ATP, eliminated accumulation of reactive oxygen species (ROS) in the Aβ oligomer-treated hippocampal slices. All these protective effects were reversed by 3-acetylpyridine, which generates inactive NAD(+). The present study indicates that NMN could restore cognition in AD model rats. The beneficial effect of NMN is produced by ameliorating neuron survival, improving energy metabolism and reducing ROS accumulation. These results suggest that NMN may become a promising therapeutic drug for AD. PMID:27130898

  12. Transnitrosylation from DJ-1 to PTEN Attenuates Neuronal Cell Death in Parkinson's Disease Models

    PubMed Central

    Choi, Min Sik; Nakamura, Tomohiro; Cho, Seung-Je; Han, Xuemei; Holland, Emily A.; Qu, Jing; Petsko, Gregory A.; Yates, John R.; Liddington, Robert C.

    2014-01-01

    Emerging evidence suggests that oxidative/nitrosative stress, as occurs during aging, contributes to the pathogenesis of Parkinson's disease (PD). In contrast, detoxification of reactive oxygen species and reactive nitrogen species can protect neurons. DJ-1 has been identified as one of several recessively inherited genes whose mutation can cause familial PD, and inactivation of DJ-1 renders neurons more susceptible to oxidative stress and cell death. DJ-1 is also known to regulate the activity of the phosphatase and tensin homolog (PTEN), which plays a critical role in neuronal cell death in response to various insults. However, mechanistic details delineating how DJ-1 regulates PTEN activity remain unknown. Here, we report that PTEN phosphatase activity is inhibited via a transnitrosylation reaction [i.e., transfer of a nitric oxide (NO) group from the cysteine residue of one protein to another]. Specifically, we show that DJ-1 is S-nitrosylated (forming SNO-DJ-1); subsequently, the NO group is transferred from DJ-1 to PTEN by transnitrosylation. Moreover, we detect SNO-PTEN in human brains with sporadic PD. Using x-ray crystallography and site-directed mutagenesis, we find that Cys106 is the site of S-nitrosylation on DJ-1 and that mutation of this site inhibits transnitrosylation to PTEN. Importantly, S-nitrosylation of PTEN decreases its phosphatase activity, thus promoting cell survival. These findings provide mechanistic insight into the neuroprotective role of SNO-DJ-1 by elucidating how DJ-1 detoxifies NO via transnitrosylation to PTEN. Dysfunctional DJ-1, which lacks this transnitrosylation activity due to mutation or prior oxidation (e.g., sulfonation) of the critical cysteine thiol, could thus contribute to neurodegenerative disorders like PD. PMID:25378175

  13. Mitochondrial Translocation of High Mobility Group Box 1 Facilitates LIM Kinase 2-Mediated Programmed Necrotic Neuronal Death.

    PubMed

    Hyun, Hye-Won; Ko, Ah-Reum; Kang, Tae-Cheon

    2016-01-01

    High mobility group box 1 (HMGB1) acts a signaling molecule regulating a wide range of inflammatory responses in extracellular space. HMGB1 also stabilizes nucleosomal structure and facilitates gene transcription. Under pathophysiological conditions, nuclear HMGB1 is immediately transported to the cytoplasm through chromosome region maintenance 1 (CRM1). Recently, we have reported that up-regulation of LIM kinase 2 (LIMK2) expression induces HMGB1 export from neuronal nuclei during status epilepticus (SE)-induced programmed neuronal necrosis in the rat hippocampus. Thus, we investigated whether HMGB1 involves LIMK2-mediated programmed neuronal necrosis, but such role is not reported. In the present study, SE was induced by pilocarpine in rats that were intracerebroventricularly infused with saline, control siRNA, LIMK2 siRNA or leptomycin B (LMB, a CRM1 inhibitor) prior to SE induction. Thereafter, we performed Fluoro-Jade B staining, western blots and immunohistochemical studies. LIMK2 knockdown effectively attenuated SE-induced neuronal death and HMGB1 import into mitochondria accompanied by inhibiting nuclear HMGB1 release and abnormal mitochondrial elongation. LMB alleviated SE-induced neuronal death and nuclear HMGB1 release. However, LMB did not prevent mitochondrial elongation induced by SE, but inhibited the HMGB1 import into mitochondria. The efficacy of LMB was less effective to attenuate SE-induced neuronal death than that of LIMK2 siRNA. These findings indicate that nuclear HMGB1 release and the subsequent mitochondrial import may facilitate and deteriorate programmed necrotic neuronal deaths. The present data suggest that the nuclear HMGB1 release via CRM1 may be a potential therapeutic target for the programmed necrotic neuronal death induced by SE. PMID:27147971

  14. Mitochondrial Translocation of High Mobility Group Box 1 Facilitates LIM Kinase 2-Mediated Programmed Necrotic Neuronal Death

    PubMed Central

    Hyun, Hye-Won; Ko, Ah-Reum; Kang, Tae-Cheon

    2016-01-01

    High mobility group box 1 (HMGB1) acts a signaling molecule regulating a wide range of inflammatory responses in extracellular space. HMGB1 also stabilizes nucleosomal structure and facilitates gene transcription. Under pathophysiological conditions, nuclear HMGB1 is immediately transported to the cytoplasm through chromosome region maintenance 1 (CRM1). Recently, we have reported that up-regulation of LIM kinase 2 (LIMK2) expression induces HMGB1 export from neuronal nuclei during status epilepticus (SE)-induced programmed neuronal necrosis in the rat hippocampus. Thus, we investigated whether HMGB1 involves LIMK2-mediated programmed neuronal necrosis, but such role is not reported. In the present study, SE was induced by pilocarpine in rats that were intracerebroventricularly infused with saline, control siRNA, LIMK2 siRNA or leptomycin B (LMB, a CRM1 inhibitor) prior to SE induction. Thereafter, we performed Fluoro-Jade B staining, western blots and immunohistochemical studies. LIMK2 knockdown effectively attenuated SE-induced neuronal death and HMGB1 import into mitochondria accompanied by inhibiting nuclear HMGB1 release and abnormal mitochondrial elongation. LMB alleviated SE-induced neuronal death and nuclear HMGB1 release. However, LMB did not prevent mitochondrial elongation induced by SE, but inhibited the HMGB1 import into mitochondria. The efficacy of LMB was less effective to attenuate SE-induced neuronal death than that of LIMK2 siRNA. These findings indicate that nuclear HMGB1 release and the subsequent mitochondrial import may facilitate and deteriorate programmed necrotic neuronal deaths. The present data suggest that the nuclear HMGB1 release via CRM1 may be a potential therapeutic target for the programmed necrotic neuronal death induced by SE. PMID:27147971

  15. Treatment advances have not improved the early death rate in acute promyelocytic leukemia

    PubMed Central

    McClellan, James Scott; Kohrt, Holbrook E.; Coutre, Steven; Gotlib, Jason R.; Majeti, Ravindra; Alizadeh, Ash A.; Medeiros, Bruno C.

    2012-01-01

    Early mortality in acute promyelocytic leukemia has been reported to occur in less than 10% of patients treated in clinical trials. This study reports the incidence and clinical features of acute promyelocytic leukemia patients treated at Stanford Hospital, CA, USA since March 1997, focusing on early mortality. We show that the risk of early death in acute promyelocytic leukemia patients is higher than previously reported. In a cohort of 70 patients who received induction therapy at Stanford Hospital, 19% and 26% died within seven and 30 days of admission, respectively. High early mortality was not limited to our institution as evaluation of the Surveillance, Epidemiology and End Results Database demonstrated that 30-day mortality for acute promyelocytic leukemia averaged 20% from 1977–2007 and did not improve significantly over this interval. Our findings show that early death is now the greatest contributor to treatment failure in this otherwise highly curable form of leukemia. PMID:21993679

  16. 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

  17. A TNF receptor 2 selective agonist rescues human neurons from oxidative stress-induced cell death.

    PubMed

    Fischer, Roman; Maier, Olaf; Siegemund, Martin; Wajant, Harald; Scheurich, Peter; Pfizenmaier, Klaus

    2011-01-01

    Tumor necrosis factor (TNF) plays a dual role in neurodegenerative diseases. Whereas TNF receptor (TNFR) 1 is predominantly associated with neurodegeneration, TNFR2 is involved in tissue regeneration and neuroprotection. Accordingly, the availability of TNFR2-selective agonists could allow the development of new therapeutic treatments of neurodegenerative diseases. We constructed a soluble, human TNFR2 agonist (TNC-scTNF(R2)) by genetic fusion of the trimerization domain of tenascin C to a TNFR2-selective single-chain TNF molecule, which is comprised of three TNF domains connected by short peptide linkers. TNC-scTNF(R2) specifically activated TNFR2 and possessed membrane-TNF mimetic activity, resulting in TNFR2 signaling complex formation and activation of downstream signaling pathways. Protection from neurodegeneration was assessed using the human dopaminergic neuronal cell line LUHMES. First we show that TNC-scTNF(R2) interfered with cell death pathways subsequent to H(2)O(2) exposure. Protection from cell death was dependent on TNFR2 activation of the PI3K-PKB/Akt pathway, evident from restoration of H(2)O(2) sensitivity in the presence of PI3K inhibitor LY294002. Second, in an in vitro model of Parkinson disease, TNC-scTNF(R2) rescues neurons after induction of cell death by 6-OHDA. Since TNFR2 is not only promoting anti-apoptotic responses but also plays an important role in tissue regeneration, activation of TNFR2 signaling by TNC-scTNF(R2) appears a promising strategy to ameliorate neurodegenerative processes. PMID:22110694

  18. A TNF Receptor 2 Selective Agonist Rescues Human Neurons from Oxidative Stress-Induced Cell Death

    PubMed Central

    Fischer, Roman; Maier, Olaf; Siegemund, Martin; Wajant, Harald; Scheurich, Peter; Pfizenmaier, Klaus

    2011-01-01

    Tumor necrosis factor (TNF) plays a dual role in neurodegenerative diseases. Whereas TNF receptor (TNFR) 1 is predominantly associated with neurodegeneration, TNFR2 is involved in tissue regeneration and neuroprotection. Accordingly, the availability of TNFR2-selective agonists could allow the development of new therapeutic treatments of neurodegenerative diseases. We constructed a soluble, human TNFR2 agonist (TNC-scTNFR2) by genetic fusion of the trimerization domain of tenascin C to a TNFR2-selective single-chain TNF molecule, which is comprised of three TNF domains connected by short peptide linkers. TNC-scTNFR2 specifically activated TNFR2 and possessed membrane-TNF mimetic activity, resulting in TNFR2 signaling complex formation and activation of downstream signaling pathways. Protection from neurodegeneration was assessed using the human dopaminergic neuronal cell line LUHMES. First we show that TNC-scTNFR2 interfered with cell death pathways subsequent to H2O2 exposure. Protection from cell death was dependent on TNFR2 activation of the PI3K-PKB/Akt pathway, evident from restoration of H2O2 sensitivity in the presence of PI3K inhibitor LY294002. Second, in an in vitro model of Parkinson disease, TNC-scTNFR2 rescues neurons after induction of cell death by 6-OHDA. Since TNFR2 is not only promoting anti-apoptotic responses but also plays an important role in tissue regeneration, activation of TNFR2 signaling by TNC-scTNFR2 appears a promising strategy to ameliorate neurodegenerative processes. PMID:22110694

  19. The unexpected force of acute stroke leading to patients' sudden death as described by nurses.

    PubMed

    Rejnö, Åsa; Danielson, Ella; von Post, Iréne

    2013-03-01

    Stroke occurs suddenly and unexpectedly and its consequences can mean the difference between life and death. Research into stroke is extensive but largely focused on patients who survive. The aim of the study was to describe how nurses experience the patient's death and dying, when patients are afflicted by acute stroke and whose lives cannot be saved. The study had a descriptive design with a hermeneutical approach. Interviews were carried out with ten nurses in stroke units at three hospitals. Data were interpreted using hermeneutic textual interpretation based on Gadamer's philosophy. The study shows that sudden death, when unexpected forces intervene in the lives of patients afflicted by acute stroke, was described by the main theme sudden death - the unexpected force and the following three sub-themes: death comes unexpectedly and without warning to the patient; the relatives are at the mercy of the unexpected and the nurses find themselves in demanding situations. The new understanding emphasizes that the unexpected and demanding situations the nurses are put in can be understood as ethical dilemmas and value conflicts because they are not free to give their time to preserving the dying patient's dignity and are not able to give the good care they wish to. A more flexible organization could support the nurses in making use of the creative forces in the unexpected event which an acute stroke that leads to death constitutes. PMID:22612457

  20. Hydroxysafflor Yellow A Protects Neurons From Excitotoxic Death through Inhibition of NMDARs

    PubMed Central

    Wang, Xingtao; Ma, Zhiyuan; Fu, Zhongxiao; Gao, Su; Yang, Liu; Jin, Yan; Sun, Hui; Wang, Chaoyun; Fan, Weiming; Chen, Lin; Zheng, Qing-Yin; Bi, Guoqiang

    2016-01-01

    Excessive glutamate release causes overactivation of N-methyl d-aspartate receptors (NMDARs), leading to excitatory neuronal damage in cerebral ischemia. Hydroxysafflor yellow A (HSYA), a compound extracted from Carthamus tinctorius L., has been reported to exert a neuroprotective effect in many pathological conditions, including brain ischemia. However, the underlying mechanism of HSYA's effect on neurons remains elusive. In the present study, we conducted experiments using patch-clamp recording of mouse hippocampal slices. In addition, we performed Ca2+ imaging, Western blots, as well as mitochondrial-targeted circularly permuted yellow fluorescent protein transfection into cultured hippocampal neurons in order to decipher the physiological mechanism underlying HSYA's neuroprotective effect. Through the electrophysiology experiments, we found that HSYA inhibited NMDAR-mediated excitatory postsynaptic currents without affecting α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor and γ-aminobutyric acid A-type receptor-mediated currents. This inhibitory effect of HSYA on NMDARs was concentration dependent. HSYA did not show any preferential inhibition of either N-methyl d-aspartate receptor subtype 2A- or N-methyl d-aspartate receptor subtype 2B- subunit-containing NMDARs. Additionally, HSYA exhibits a facilitatory effect on paired NMDAR-mediated excitatory postsynaptic currents. Furthermore, HSYA reduced the magnitude of NMDAR-mediated membrane depolarization currents evoked by oxygen-glucose deprivation, and suppressed oxygen-glucose deprivation–induced and NMDAR-dependent ischemic long-term potentiation, which is believed to cause severe reperfusion damage after ischemia. Through the molecular biology experiments, we found that HSYA inhibited the NMDA-induced and NMDAR-mediated intracellular Ca2+ concentration increase in hippocampal cultures, reduced apoptotic and necrotic cell deaths, and prevented mitochondrial damage. Together, our data

  1. Hydroxysafflor Yellow A Protects Neurons From Excitotoxic Death through Inhibition of NMDARs.

    PubMed

    Wang, Xingtao; Ma, Zhiyuan; Fu, Zhongxiao; Gao, Su; Yang, Liu; Jin, Yan; Sun, Hui; Wang, Chaoyun; Fan, Weiming; Chen, Lin; Zheng, Qing-Yin; Bi, Guoqiang; Ma, Chun-Lei

    2016-01-01

    Excessive glutamate release causes overactivation of N-methyld-aspartate receptors (NMDARs), leading to excitatory neuronal damage in cerebral ischemia. Hydroxysafflor yellow A (HSYA), a compound extracted from Carthamus tinctorius L., has been reported to exert a neuroprotective effect in many pathological conditions, including brain ischemia. However, the underlying mechanism of HSYA's effect on neurons remains elusive. In the present study, we conducted experiments using patch-clamp recording of mouse hippocampal slices. In addition, we performed Ca(2+) imaging, Western blots, as well as mitochondrial-targeted circularly permuted yellow fluorescent protein transfection into cultured hippocampal neurons in order to decipher the physiological mechanism underlying HSYA's neuroprotective effect.Through the electrophysiology experiments, we found that HSYA inhibited NMDAR-mediated excitatory postsynaptic currents without affecting α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor and γ-aminobutyric acid A-type receptor-mediated currents. This inhibitory effect of HSYA on NMDARs was concentration dependent. HSYA did not show any preferential inhibition of either N-methyld-aspartate receptor subtype 2A- or N-methyld-aspartate receptor subtype 2B- subunit-containing NMDARs. Additionally, HSYA exhibits a facilitatory effect on paired NMDAR-mediated excitatory postsynaptic currents. Furthermore, HSYA reduced the magnitude of NMDAR-mediated membrane depolarization currents evoked by oxygen-glucose deprivation, and suppressed oxygen-glucose deprivation-induced and NMDAR-dependent ischemic long-term potentiation, which is believed to cause severe reperfusion damage after ischemia. Through the molecular biology experiments, we found that HSYA inhibited the NMDA-induced and NMDAR-mediated intracellular Ca(2+)concentration increase in hippocampal cultures, reduced apoptotic and necrotic cell deaths, and prevented mitochondrial damage. Together, our data

  2. Higher sensitivity to cadmium induced cell death of basal forebrain cholinergic neurons: a cholinesterase dependent mechanism.

    PubMed

    Del Pino, Javier; Zeballos, Garbriela; Anadon, María José; Capo, Miguel Andrés; Díaz, María Jesús; García, Jimena; Frejo, María Teresa

    2014-11-01

    Cadmium is an environmental pollutant, which is a cause of concern because it can be greatly concentrated in the organism causing severe damage to a variety of organs including the nervous system which is one of the most affected. Cadmium has been reported to produce learning and memory dysfunctions and Alzheimer like symptoms, though the mechanism is unknown. On the other hand, cholinergic system in central nervous system (CNS) is implicated on learning and memory regulation, and it has been reported that cadmium can affect cholinergic transmission and it can also induce selective toxicity on cholinergic system at peripheral level, producing cholinergic neurons loss, which may explain cadmium effects on learning and memory processes if produced on central level. The present study is aimed at researching the selective neurotoxicity induced by cadmium on cholinergic system in CNS. For this purpose we evaluated, in basal forebrain region, the cadmium toxic effects on neuronal viability and the cholinergic mechanisms related to it on NS56 cholinergic mourine septal cell line. This study proves that cadmium induces a more pronounced, but not selective, cell death on acetylcholinesterase (AChE) on cholinergic neurons. Moreover, MTT and LDH assays showed a dose dependent decrease of cell viability in NS56 cells. The ACh treatment of SN56 cells did not revert cell viability reduction induced by cadmium, but siRNA transfection against AChE partially reduced it. Our present results provide new understanding of the mechanisms contributing to the harmful effects of cadmium on the function and viability of neurons, and the possible relevance of cadmium in the pathogenesis of neurodegenerative diseases. PMID:25201352

  3. Neuroinflammation in Parkinson’s disease: its role in neuronal death and implications for therapeutic intervention

    PubMed Central

    Tansey, Malú G.; Goldberg, Matthew S.

    2009-01-01

    disease, etc.), increasing the vulnerability to inflammation-induced nigral DA neuron death and predisposing an individual to development of PD. Lastly, we review the latest epidemiological and experimental evidence supporting the potential use of anti-inflammatory and immunomodulatory drugs as neuroprotective agents to delay the progressive nigrostriatal degeneration that leads to motor dysfunction in PD. PMID:19913097

  4. Rescuing neuronal cell death by RAIDD- and PIDD- derived peptides and its implications for therapeutic intervention in neurodegenerative diseases

    PubMed Central

    Jang, Tae-Ho; Lim, In-Hye; Kim, Chang Min; Choi, Jae Young; Kim, Eun-Ae; Lee, Tae-Jin; Park, Hyun Ho

    2016-01-01

    Caspase-2 is known to be involved in oxidative-stress mediated neuronal cell death. In this study, we demonstrated that rotenone-induced neuronal cell death is mediated by caspase-2 activation via PIDDosome formation. Our newly designed TAT-fused peptides, which contains wild-type helix number3 (H3) from RAIDD and PIDD, blocked the PIDDosome formation in vitro. Furthermore, peptides inhibited rotenone-induced caspase-2-dependent apoptosis in neuronal cells. These results suggest that PIDD- or RAIDD-targeted peptides might be effective at protecting against rotenone-induced neurotoxicity. Our peptides are novel neuronal cell apoptosis inhibitors that might serve as a prototype for development of drugs for the treatment of neurodegenerative diseases. PMID:27502430

  5. Rescuing neuronal cell death by RAIDD- and PIDD- derived peptides and its implications for therapeutic intervention in neurodegenerative diseases.

    PubMed

    Jang, Tae-Ho; Lim, In-Hye; Kim, Chang Min; Choi, Jae Young; Kim, Eun-Ae; Lee, Tae-Jin; Park, Hyun Ho

    2016-01-01

    Caspase-2 is known to be involved in oxidative-stress mediated neuronal cell death. In this study, we demonstrated that rotenone-induced neuronal cell death is mediated by caspase-2 activation via PIDDosome formation. Our newly designed TAT-fused peptides, which contains wild-type helix number3 (H3) from RAIDD and PIDD, blocked the PIDDosome formation in vitro. Furthermore, peptides inhibited rotenone-induced caspase-2-dependent apoptosis in neuronal cells. These results suggest that PIDD- or RAIDD-targeted peptides might be effective at protecting against rotenone-induced neurotoxicity. Our peptides are novel neuronal cell apoptosis inhibitors that might serve as a prototype for development of drugs for the treatment of neurodegenerative diseases. PMID:27502430

  6. Isolated primary blast alters neuronal function with minimal cell death in organotypic hippocampal slice cultures.

    PubMed

    Effgen, Gwen B; Vogel, Edward W; Lynch, Kimberly A; Lobel, Ayelet; Hue, Christopher D; Meaney, David F; Bass, Cameron R Dale; Morrison, Barclay

    2014-07-01

    An increasing number of U.S. soldiers are diagnosed with traumatic brain injury (TBI) subsequent to exposure to blast. In the field, blast injury biomechanics are highly complex and multi-phasic. The pathobiology caused by exposure to some of these phases in isolation, such as penetrating or inertially driven injuries, has been investigated extensively. However, it is unclear whether the primary component of blast, a shock wave, is capable of causing pathology on its own. Previous in vivo studies in the rodent and pig have demonstrated that it is difficult to deliver a primary blast (i.e., shock wave only) without rapid head accelerations and potentially confounding effects of inertially driven TBI. We have previously developed a well-characterized shock tube and custom in vitro receiver for exposing organotypic hippocampal slice cultures to pure primary blast. In this study, isolated primary blast induced minimal hippocampal cell death (on average, below 14% in any region of interest), even for the most severe blasts tested (424 kPa peak pressure, 2.3 ms overpressure duration, and 248 kPa*ms impulse). In contrast, measures of neuronal function were significantly altered at much lower exposures (336 kPa, 0.84 ms, and 86.5 kPa*ms), indicating that functional changes occur at exposures below the threshold for cell death. This is the first study to investigate a tolerance for primary blast-induced brain cell death in response to a range of blast parameters and demonstrate functional deficits at subthreshold exposures for cell death. PMID:24558968

  7. The factors affecting early death after the initial therapy of acute myeloid leukemia

    PubMed Central

    Malkan, Umit Yavuz; Gunes, Gursel; Eliacik, Eylem; Haznedaroglu, Ibrahim Celalettin; Etgul, Sezgin; Aslan, Tuncay; Yayar, Okan; Aydin, Seda; Demiroglu, Haluk; Ozcebe, Osman Ilhami; Sayinalp, Nilgun; Goker, Hakan; Aksu, Salih; Buyukasik, Yahya

    2015-01-01

    There are some improvements in management of acute myeloid leukemia (AML). However, induction-induced deaths still remain as a major problem. The aim of this study is to assess clinical parameters affecting early death in patients with AML. 199 AML patients, who were treated with intensive, non-intensive or supportive treatment between 2002 and 2014 in Hacettepe Hematology Department, were analyzed retrospectively. In our study early death rate for elderly was found to be lower than previous reports whereas it was similar for those who were under age of 60. Better ECOG performance (ECOG performance score 0 and 1) and non-intensive treatment associated with lower early death rates, however APL-type disease associated with higher early death rates. ECOG performance score at diagnosis was found to be the most related independent factor with higher rate of early death in 15 days after treatment (P<0.001). Therefore we decided to understand the factors which were related with ECOG. WBC count at diagnosis was found to be the only related parameter with ECOG performance score. Leucocyte count at diagnosis appears like to have an indirect effect on early death in AML patients. It maybe suggested that in recent years there is an improvement in early death rates of elderly AML patients. The currently reported findings require prospective validation and would encourage the incorporation of other next generation genomics for the prediction of early death and overall risk status of AML. PMID:26885243

  8. In vitro research of the alteration of neurons in vagal core in medulla oblongata at asphyxic deaths.

    PubMed

    Haliti, Naim; Islami, Hilmi; Elezi, Nevzat; Shabani, Ragip; Abdullahu, Bedri; Dragusha, Gani

    2010-08-01

    The aim of this study was to research the morphological changes of neurons in the vagus nerve nuclei in medulla oblongata in asphyxia related death cases. Morphological changes that were investigated were mainly in the dorsal motor respiratory center (DMRC), nucleus tractus solitarius (nTS) and nucleus ambigus (nA) in the medulla oblongata. In our research, the autopsy material from asphyxia related death cases was used from various etiologies: monoxide carbon (CO), liquid drowning, strangulation, electricity, clinical-pathological death, firing weapon, explosive weapon, sharp and blunt objects and death cases due to accident. The material selected for research was taken from medulla oblongata and lungs from all lobes. The material from the medulla oblongata and lungs was fixed in a 10% solution of buffered formalin. Special histochemical methods for central nervous system (CNS) were employed like: Cresyl echt violet, toluidin blue, Sevier-Munger modification and Grimelius. For stereometrical analysis of the quantitative density of the neurons the universal testing system Weibel M42 was used. The acquired results show that in sudden asphyxia related death cases, there are alterations in the nuclei of vagal nerve in form of: central chromatolysis, axonal retraction, axonal fragmentation, intranuclear vacuolization, cytoplasmic vacuolization, edema, condensation and dispersion of substance of Nissl, proliferation of oligodendrocytes, astrocytes and microglia. The altered population of vagus nerve neurons does not show an important statistical significance compared to the overall quantity of the neurons in the nuclei of the vagus nerve (p<0.05). PMID:20846134

  9. Defect in synaptic vesicle precursor transport and neuronal cell death in KIF1A motor protein-deficient mice.

    PubMed

    Yonekawa, Y; Harada, A; Okada, Y; Funakoshi, T; Kanai, Y; Takei, Y; Terada, S; Noda, T; Hirokawa, N

    1998-04-20

    The nerve axon is a good model system for studying the molecular mechanism of organelle transport in cells. Recently, the new kinesin superfamily proteins (KIFs) have been identified as candidate motor proteins involved in organelle transport. Among them KIF1A, a murine homologue of unc-104 gene of Caenorhabditis elegans, is a unique monomeric neuron- specific microtubule plus end-directed motor and has been proposed as a transporter of synaptic vesicle precursors (Okada, Y., H. Yamazaki, Y. Sekine-Aizawa, and N. Hirokawa. 1995. Cell. 81:769-780). To elucidate the function of KIF1A in vivo, we disrupted the KIF1A gene in mice. KIF1A mutants died mostly within a day after birth showing motor and sensory disturbances. In the nervous systems of these mutants, the transport of synaptic vesicle precursors showed a specific and significant decrease. Consequently, synaptic vesicle density decreased dramatically, and clusters of clear small vesicles accumulated in the cell bodies. Furthermore, marked neuronal degeneration and death occurred both in KIF1A mutant mice and in cultures of mutant neurons. The neuronal death in cultures was blocked by coculture with wild-type neurons or exposure to a low concentration of glutamate. These results in cultures suggested that the mutant neurons might not sufficiently receive afferent stimulation, such as neuronal contacts or neurotransmission, resulting in cell death. Thus, our results demonstrate that KIF1A transports a synaptic vesicle precursor and that KIF1A-mediated axonal transport plays a critical role in viability, maintenance, and function of neurons, particularly mature neurons. PMID:9548721

  10. Airborne nanoparticles (PM0.1 ) induce autophagic cell death of human neuronal cells.

    PubMed

    Jeon, Yu-Mi; Lee, Mi-Young

    2016-10-01

    Airborne nanoparticles PM0.1 (<100 nm in diameter) were collected and their chemical composition was determined. Al was by far the most abundant metal in the PM0.1 followed by Zn, Cr, Mn, Cu, Pb and Ni. Exposure to PM0.1 resulted in a cell viability decrease in human neuronal cells SH-SY5Y in a concentration-dependent manner. Upon treatment with N-acetylcysteine, however, cell viability was significantly recovered, suggesting the involvement of reactive oxygen species (ROS). Cellular DNA damage by PM0.1 was also detected by the Comet assay. PM0.1 -induced autophagic cell death was explained by an increase in the expression of microtubule-associated protein light chain 3A-ІІ (LC3A-ІІ) and autophagy-related protein Atg 3 and Atg 7. Analysis of 2-DE gels revealed that six proteins were upregulated, whereas eight proteins were downregulated by PM0.1 exposure. Neuroinflammation-related lithostathine and cyclophilin A complexed with dipeptide Gly-Pro, autophagy-related heat shock protein gp96 and neurodegeneration-related triosephosphate isomerase were significantly changed upon exposure to PM0.1 . These results, taken together, suggest that PM0.1 -induced oxidative stress via ROS generation plays a key role in autophagic cell death and differential protein expressions in SH-SY5Y cells. This might provide a plausible explanation for the underlying mechanisms of PM0.1 toxicity in neuronal cells and even the pathogenesis of diseases associated with its exposure. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27080386

  11. Quercetin attenuates neuronal death against aluminum-induced neurodegeneration in the rat hippocampus.

    PubMed

    Sharma, D R; Wani, W Y; Sunkaria, A; Kandimalla, R J; Sharma, R K; Verma, D; Bal, A; Gill, K D

    2016-06-01

    Aluminum is a light weight and toxic metal present ubiquitously on earth, which has gained considerable attention due to its neurotoxic effects. It also has been linked ecologically and epidemiologically to several neurological disorders, including Alzheimer's disease (AD), Parkinson's disease (PD), Guamanian-Parkinsonian complex and Amyotrophic lateral sclerosis (ALS). The mechanism of aluminum neurotoxicity is poorly understood, but it is well documented that aluminum generates reactive oxygen species (ROS). Enhanced ROS production leads to disruption of cellular antioxidant defense systems and release of cytochrome c (cyt-c) from mitochondria to cytosol resulting in apoptotic cell death. Quercetin (a natural flavonoid) protects it from oxidative damage and has been shown to decrease mitochondrial damage in various animal models of oxidative stress. We hypothesized that if oxidative damage to mitochondria does play a significant role in aluminum-induced neurodegeneration, and then quercetin should ameliorate neuronal apoptosis. Administration of quercetin (10mg/kg body wt/day) reduced aluminum (10mg/kg body wt/day)-induced oxidative stress (decreased ROS production, increased mitochondrial superoxide dismutase (MnSOD) activity). In addition, quercetin also prevents aluminum-induced translocation of cyt-c, and up-regulates Bcl-2, down-regulates Bax, p53, caspase-3 activation and reduces DNA fragmentation. Quercetin also obstructs aluminum-induced neurodegenerative changes in aluminum-treated rats as seen by Hematoxylin and Eosin (H&E) staining. Further electron microscopic studies revealed that quercetin attenuates aluminum-induced mitochondrial swelling, loss of cristae and chromatin condensation. These results indicate that treatment with quercetin may represent a therapeutic strategy to attenuate the neuronal death against aluminum-induced neurodegeneration. PMID:26944603

  12. APP Overexpression Causes Aβ-Independent Neuronal Death through Intrinsic Apoptosis Pathway.

    PubMed

    Cheng, Ning; Jiao, Song; Gumaste, Ankita; Bai, Li; Belluscio, Leonardo

    2016-01-01

    Accumulation of amyloid-β (Aβ) peptide in the brain is a central hallmark of Alzheimer's disease (AD) and is thought to be the cause of the observed neurodegeneration. Many animal models have been generated that overproduce Aβ yet do not exhibit clear neuronal loss, questioning this Aβ hypothesis. We previously developed an in vivo mouse model that expresses a humanized amyloid precursor protein (hAPP) in olfactory sensory neurons (OSNs) showing robust apoptosis and olfactory dysfunction by 3 weeks of age, which is consistent with early OSN loss and smell deficits, as observed in AD patients. Here we show, by deleting the β-site APP cleaving enzyme 1 (BACE1) in two distinct transgenic mouse models, that hAPP-induced apoptosis of OSNs is Aβ independent and remains cell autonomous. In addition, we reveal that the intrinsic apoptosis pathway is responsible for hAPP-induced OSN death, as marked by mitochondrial damage and caspase-9 activation. Given that hAPP expression causes OSN apoptosis despite the absence of BACE1, we propose that Aβ is not the sole cause of hAPP-induced neurodegeneration and that the early loss of olfactory function in AD may be based on a cell-autonomous mechanism, which could mark an early phase of AD, prior to Aβ accumulation. Thus, the olfactory system could serve as an important new platform to study the development of AD, providing unique insight for both early diagnosis and intervention. PMID:27517085

  13. APP Overexpression Causes Aβ-Independent Neuronal Death through Intrinsic Apoptosis Pathway

    PubMed Central

    Cheng, Ning; Jiao, Song; Gumaste, Ankita; Bai, Li

    2016-01-01

    Abstract Accumulation of amyloid-β (Aβ) peptide in the brain is a central hallmark of Alzheimer’s disease (AD) and is thought to be the cause of the observed neurodegeneration. Many animal models have been generated that overproduce Aβ yet do not exhibit clear neuronal loss, questioning this Aβ hypothesis. We previously developed an in vivo mouse model that expresses a humanized amyloid precursor protein (hAPP) in olfactory sensory neurons (OSNs) showing robust apoptosis and olfactory dysfunction by 3 weeks of age, which is consistent with early OSN loss and smell deficits, as observed in AD patients. Here we show, by deleting the β-site APP cleaving enzyme 1 (BACE1) in two distinct transgenic mouse models, that hAPP-induced apoptosis of OSNs is Aβ independent and remains cell autonomous. In addition, we reveal that the intrinsic apoptosis pathway is responsible for hAPP-induced OSN death, as marked by mitochondrial damage and caspase-9 activation. Given that hAPP expression causes OSN apoptosis despite the absence of BACE1, we propose that Aβ is not the sole cause of hAPP-induced neurodegeneration and that the early loss of olfactory function in AD may be based on a cell-autonomous mechanism, which could mark an early phase of AD, prior to Aβ accumulation. Thus, the olfactory system could serve as an important new platform to study the development of AD, providing unique insight for both early diagnosis and intervention. PMID:27517085

  14. Fermented Brown Rice Extract Causes Apoptotic Death of Human Acute Lymphoblastic Leukemia Cells via Death Receptor Pathway.

    PubMed

    Horie, Yukiko; Nemoto, Hideyuki; Itoh, Mari; Kosaka, Hiroaki; Morita, Kyoji

    2016-04-01

    Mixture of brown rice and rice bran fermented with Aspergillus oryzae, designated as FBRA, has been reported to reveal anti-carcinogenic and anti-inflammatory effects in rodents. Then, to test its potential anti-cancer activity, the aqueous extract was prepared from FBRA powder, and the effect of this extract on human acute lymphoblastic leukemia Jurkat cells was directly examined. The exposure to FBRA extract reduced the cell viability in a concentration- and time-dependent manner. The reduction of the cell viability was accompanied by the DNA fragmentation, and partially restored by treatment with pan-caspase inhibitor. Further studies showed that FBRA extract induced the cleavage of caspase-8, -9, and -3, and decreased Bcl-2 protein expression. Moreover, the expression of tBid, DR5, and Fas proteins was enhanced by FBRA extract, and the pretreatment with caspase-8 inhibitor, but not caspase-9 inhibitor, restored the reduction of the cell viability induced by FBRA extract. These findings suggested that FBRA extract could induce the apoptotic death of human acute lymphoblastic leukemia cells probably through mainly the death receptor-mediated pathway and supplementarily through the tBid-mediated mitochondrial pathway, proposing the possibility that FBRA was a potential functional food beneficial to patients with hematological cancer. PMID:26769704

  15. Aluminum adjuvant linked to Gulf War illness induces motor neuron death in mice.

    PubMed

    Petrik, Michael S; Wong, Margaret C; Tabata, Rena C; Garry, Robert F; Shaw, Christopher A

    2007-01-01

    Gulf War illness (GWI) affects a significant percentage of veterans of the 1991 conflict, but its origin remains unknown. Associated with some cases of GWI are increased incidences of amyotrophic lateral sclerosis and other neurological disorders. Whereas many environmental factors have been linked to GWI, the role of the anthrax vaccine has come under increasing scrutiny. Among the vaccine's potentially toxic components are the adjuvants aluminum hydroxide and squalene. To examine whether these compounds might contribute to neuronal deficits associated with GWI, an animal model for examining the potential neurological impact of aluminum hydroxide, squalene, or aluminum hydroxide combined with squalene was developed. Young, male colony CD-1 mice were injected with the adjuvants at doses equivalent to those given to US military service personnel. All mice were subjected to a battery of motor and cognitive-behavioral tests over a 6-mo period postinjections. Following sacrifice, central nervous system tissues were examined using immunohistochemistry for evidence of inflammation and cell death. Behavioral testing showed motor deficits in the aluminum treatment group that expressed as a progressive decrease in strength measured by the wire-mesh hang test (final deficit at 24 wk; about 50%). Significant cognitive deficits in water-maze learning were observed in the combined aluminum and squalene group (4.3 errors per trial) compared with the controls (0.2 errors per trial) after 20 wk. Apoptotic neurons were identified in aluminum-injected animals that showed significantly increased activated caspase-3 labeling in lumbar spinal cord (255%) and primary motor cortex (192%) compared with the controls. Aluminum-treated groups also showed significant motor neuron loss (35%) and increased numbers of astrocytes (350%) in the lumbar spinal cord. The findings suggest a possible role for the aluminum adjuvant in some neurological features associated with GWI and possibly an

  16. 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

  17. Rhinacanthus nasutus protects cultured neuronal cells against hypoxia induced cell death.

    PubMed

    Brimson, James M; Tencomnao, Tewin

    2011-01-01

    Rhinacanthus nasutus (L.) Kurz (Acanthaceae) is an herb native to Thailand and Southeast Asia, known for its antioxidant properties. Hypoxia leads to an increase in reactive oxygen species in cells and is a leading cause of neuronal damage. Cell death caused by hypoxia has been linked with a number of neurodegenerative diseases including some forms of dementia and stroke, as well as the build up of reactive oxygen species which can lead to diseases such as Huntington's disease, Parkinson's disease and Alzeheimer's disease. In this study we used an airtight culture container and the Mitsubishi Gas Company anaeropack along with the MTT assay, LDH assay and the trypan blue exlusion assay to show that 1 and 10 µg mL⁻¹ root extract of R. nasutus is able to significantly prevent the death of HT-22 cells subjected to hypoxic conditions, and 0.1 to 10 µg mL⁻¹ had no toxic effect on HT-22 under normal conditions, whereas 100 µg mL⁻¹ reduced HT-22 cell proliferation. We also used H₂DCFDA staining to show R. nasutus can reduce reactive oxygen species production in HT-22 cells. PMID:21792150

  18. Necroptosis drives motor neuron death in models of both sporadic and familial ALS

    PubMed Central

    Re, Diane B.; Verche, Virginia Le; Yu, Changhao; Amoroso, Mackenzie W.; Politi, Kristin A.; Phani, Sudarshan; Ikiz, Burcin; Hoffmann, Lucas; Koolen, Martijn; Nagata, Tetsuya; Papadimitriou, Dimitra; Nagy, Peter; Mitsumoto, Hiroshi; Kariya, Shingo; Wichterle, Hynek; Henderson, Christopher E.; Przedborski, Serge

    2014-01-01

    SUMMARY Most cases of neurodegenerative disease are sporadic, hindering the use of genetic mouse models to analyze disease mechanisms. Focusing on the motor neuron (MN) disease amyotrophic lateral sclerosis (ALS) we therefore devised a fully humanized co-culture model composed of human adult primary sporadic ALS (sALS) astrocytes and human embryonic stem cell-derived MNs. The model reproduces the cardinal features of human ALS: sALS astrocytes, but not those from control patients, trigger selective death of MNs. The mechanisms underlying this non-cell-autonomous toxicity were investigated in both astrocytes and MNs. Although causal in familial ALS (fALS), SOD1 does not contribute to the toxicity of sALS astrocytes. Death of MNs triggered by either sALS or fALS astrocytes occurs through necroptosis, a form of programmed necrosis involving receptor-interacting protein 1 and the mixed lineage kinase domain-like protein. The necroptotic pathway therefore constitutes a novel potential therapeutic target for this incurable disease. PMID:24508385

  19. Neuronal NAD(P)H Oxidases Contribute to ROS Production and Mediate RGC Death after Ischemia

    PubMed Central

    Dvoriantchikova, Galina; Grant, Jeff; Santos, Andrea Rachelle C.; Hernandez, Eleut; Ivanov, Dmitry

    2012-01-01

    Purpose. To study the role of neuronal nicotinamide adenine dinucleotide phosphate [NAD(P)H] oxidase–dependent reactive oxygen species (ROS) production in retinal ganglion cell (RGC) death after ischemia. Methods. Ischemic injury was induced by unilateral elevation of intraocular pressure via direct corneal cannulation. For in vitro experiments, RGCs isolated by immunopanning from retinas were exposed to oxygen and glucose deprivation (OGD). The expression levels of NAD(P)H oxidase subunits were evaluated by quantitative PCR, immunocytochemistry, and immunohistochemistry. The level of ROS generated was assayed by dihydroethidium. The NAD(P)H oxidase inhibitors were then tested to determine if inhibition of NAD(P)H oxidase altered the production of ROS within the RGCs and promoted cell survival. Results. It was reported that RGCs express catalytic Nox1, Nox2, Nox4, Duox1, as well as regulatory Ncf1/p47phox, Ncf2/p67phox, Cyba/p22phox, Noxo1, and Noxa1 subunits of NAD(P)H oxidases under normal conditions and after ischemia. However, whereas RGCs express only low levels of catalytic Nox2, Nox4, and Duox1, and regulatory Ncf1/p47, Ncf2/p67 subunits, they exhibit significantly higher levels of catalytic subunit Nox1 and the subunits required for optimal activity of Nox1. It was observed that the nonselective NAD(P)H oxidase inhibitors VAS-2870, AEBSF, and the Nox1 NAD(P)H oxidase–specific inhibitor ML-090 decreased the ROS burst stimulated by OGD, which was associated with a decreased level of RGC death. Conclusions. The findings suggest that NAD(P)H oxidase activity in RGCs renders them vulnerable to ischemic death. Importantly, high levels of Nox1 NAD(P)H oxidase subunits in RGCs suggest that this enzyme could be a major source of ROS in RGCs produced by NAD(P)H oxidases. PMID:22467573

  20. Arctic ground squirrel neuronal progenitor cells resist oxygen and glucose deprivation-induced death

    PubMed Central

    Drew, Kelly L; Wells, Matthew; McGee, Rebecca; Ross, Austin P; Kelleher-Andersson, Judith

    2016-01-01

    AIM: To investigate the influence of ischemia/reperfusion on arctic ground squirrel (AGS) neuronal progenitor cells (NPCs), we subjected these cultured cells to oxygen and glucose deprivation. METHODS: AGS NPCs were expanded and differentiated into NPCs and as an ischemia vulnerable control, commercially available human NPCs (hNPCs) were seeded from thawed NPCs. NPCs, identified by expression of TUJ1 were seen at 14-21 d in vitro (DIV). Cultures were exposed to control conditions, hypoxia, oxygen and glucose deprivation or glucose deprivation alone or following return to normal conditions to model reperfusion. Cell viability and death were assessed from loss of ATP as well as from measures of alamarBlue® and lactate dehydrogenase in the media and from counts of TUJ1 positive cells using immunocytochemistry. Dividing cells were identified by expression of Ki67 and phenotyped by double labeling with GFAP, MAP2ab or TUJ1. RESULTS: We report that when cultured in NeuraLife™, AGS cells remain viable out to 21 DIV, continue to express TUJ1 and begin to express MAP2ab. Viability of hNPCs assessed by fluorescence alamarBlue (arbitrary units) depends on both glucose and oxygen availability [viability of hNPCs after 24 h oxygen glucose deprivation (OGD) with return of oxygen and glucose decreased from 48151 ± 4551 in control cultures to 43481 ± 2413 after OGD, P < 0.05]. By contrast, when AGS NPCs are exposed to the same OGD with reperfusion at 14 DIV, cell viability assessed by alamarBlue increased from 165305 ± 11719 in control cultures to 196054 ± 13977 after OGD. Likewise AGS NPCs recovered ATP (92766 ± 6089 in control and 92907 ± 4290 after modeled reperfusion; arbitrary luminescence units), and doubled in the ratio of TUJ1 expressing neurons to total dividing cells (0.11 ± 0.04 in control cultures vs 0.22 ± 0.2 after modeled reperfusion, P < 0.05). Maintaining AGS NPCs for a longer time in culture lowered resistance to injury, however, did not impair

  1. Involvement of decreased glutamate receptor subunit GluR2 expression in lead-induced neuronal cell death.

    PubMed

    Ishida, Keishi; Kotake, Yaichiro; Miyara, Masatsugu; Aoki, Kaori; Sanoh, Seigo; Kanda, Yasunari; Ohta, Shigeru

    2013-01-01

    Lead is known to induce neurotoxicity, particularly in young children, and GluR2, an AMPA-type glutamate receptor subunit, plays an important role in neuronal cell survival. Therefore, we hypothesized that altered GluR2 expression plays a role in lead-induced neuronal cell death. To test this idea, we investigated the effect of exposure to 5 and 20 µM lead for 1-9 days on the viability and GluR2 expression of primary-cultured rat cortical neurons. The number of trypan-blue stained cells was increased by exposure to 5 µM lead for 9 days or 20 µM lead for 7-9 days, and LDH release was increased after exposure to 20 µM lead for 9 days. GluR2 expression was reduced by exposure to 5-100 µM lead, but not 0.1-1 µM lead, for 9 days. Immunocytochemistry also confirmed that GluR2 expression was decreased in the presence of lead. Application of 50 ng/ml brain-derived neurotrophic factor (BDNF) led to a recovery of lead-induced neuronal cell death, accompanied with increased GluR2 expression. Our results suggest that long-term exposure to lead induces neuronal cell death, in association with a decrease of GluR2 expression. PMID:23719929

  2. Clinical presentation and in-hospital death in acute pulmonary embolism: does cancer matter?

    PubMed

    Casazza, Franco; Becattini, Cecilia; Rulli, Eliana; Pacchetti, Ilaria; Floriani, Irene; Biancardi, Marco; Scardovi, Angela Beatrice; Enea, Iolanda; Bongarzoni, Amedeo; Pignataro, Luigi; Agnelli, Giancarlo

    2016-09-01

    Cancer is one of the most common risk factors for acute pulmonary embolism (PE), but only few studies report on the short-term outcome of patients with PE and a history of cancer. The aim of the study was to assess whether a cancer diagnosis affects the clinical presentation and short-term outcome in patients hospitalized for PE who were included in the Italian Pulmonary Embolism Registry. All-cause and PE-related in-hospital deaths were also analyzed. Out of 1702 patients, 451 (26.5 %) of patients had a diagnosis of cancer: cancer was known at presentation in 365, or diagnosed during the hospital stay for PE in 86 (19 % of cancer patients). Patients with and without cancer were similar concerning clinical status at presentation. Patients with cancer less commonly received thrombolytic therapy, and more often had an inferior vena cava filter inserted. Major or intracranial bleeding was not different between groups. In-hospital all-cause death occurred in 8.4 and 5.9 % of patients with and without cancer, respectively. At multivariate analysis, cancer (OR 2.24, 95 % CI 1.27-3.98; P = 0.006) was an independent predictor of in-hospital death. Clinical instability, PE recurrence, age ≥75 years, recent bed rest ≥3 days, but not cancer, were independent predictors of in-hospital death due to PE. Cancer seems a weaker predictor of all-cause in-hospital death compared to other factors; the mere presence of cancer, without other risk factors, leads to a probability of early death of 2 %. In patients with acute PE, cancer increases the probability of in-hospital all-cause death, but does not seem to affect the clinical presentation or the risk of in-hospital PE-related death. PMID:27023066

  3. Arginine vasopressin neuronal loss results from autophagy-associated cell death in a mouse model for familial neurohypophysial diabetes insipidus.

    PubMed

    Hagiwara, D; Arima, H; Morishita, Y; Wenjun, L; Azuma, Y; Ito, Y; Suga, H; Goto, M; Banno, R; Sugimura, Y; Shiota, A; Asai, N; Takahashi, M; Oiso, Y

    2014-01-01

    Familial neurohypophysial diabetes insipidus (FNDI) characterized by progressive polyuria is mostly caused by mutations in the gene encoding neurophysin II (NPII), which is the carrier protein of the antidiuretic hormone, arginine vasopressin (AVP). Although accumulation of mutant NPII in the endoplasmic reticulum (ER) could be toxic for AVP neurons, the precise mechanisms of cell death of AVP neurons, reported in autopsy studies, remain unclear. Here, we subjected FNDI model mice to intermittent water deprivation (WD) in order to promote the phenotypes. Electron microscopic analyses demonstrated that, while aggregates are confined to a certain compartment of the ER in the AVP neurons of FNDI mice with water access ad libitum, they were scattered throughout the dilated ER lumen in the FNDI mice subjected to WD for 4 weeks. It is also demonstrated that phagophores, the autophagosome precursors, emerged in the vicinity of aggregates and engulfed the ER containing scattered aggregates. Immunohistochemical analyses revealed that expression of p62, an adapter protein between ubiquitin and autophagosome, was elicited on autophagosomal membranes in the AVP neurons, suggesting selective autophagy induction at this time point. Treatment of hypothalamic explants of green fluorescent protein (GFP)-microtubule-associated protein 1 light chain 3 (LC3) transgenic mice with an ER stressor thapsigargin increased the number of GFP-LC3 puncta, suggesting that ER stress could induce autophagosome formation in the hypothalamus of wild-type mice as well. The cytoplasm of AVP neurons in FNDI mice was occupied with vacuoles in the mice subjected to WD for 12 weeks, when 30-40% of AVP neurons are lost. Our data thus demonstrated that autophagy was induced in the AVP neurons subjected to ER stress in FNDI mice. Although autophagy should primarily be protective for neurons, it is suggested that the organelles including ER were lost over time through autophagy, leading to autophagy

  4. 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

  5. Tat-NOL3 protects against hippocampal neuronal cell death induced by oxidative stress through the regulation of apoptotic pathways.

    PubMed

    Sohn, Eun Jeong; Shin, Min Jea; Eum, Won Sik; Kim, Dae Won; Yong, Ji In; Ryu, Eun Ji; Park, Jung Hwan; Cho, Su Bin; Cha, Hyun Ju; Kim, Sang Jin; Yeo, Hyeon Ji; Yeo, Eun Ji; Choi, Yeon Joo; Im, Seung Kwon; Kweon, Hae Young; Kim, Duk-Soo; Yu, Yeon Hee; Cho, Sung-Woo; Park, Meeyoung; Park, Jinseu; Cho, Yong-Jun; Choi, Soo Young

    2016-07-01

    Oxidative stress-induced apoptosis is associated with neuronal cell death and ischemia. The NOL3 [nucleolar protein 3 (apoptosis repressor with CARD domain)] protein protects against oxidative stress-induced cell death. However, the protective mechanism responsible for this effect as well as the effects of NOL3 against oxidative stress in ischemia remain unclear. Thus, we examined the protective effects of NOL3 protein on hydrogen peroxide (H2O2)-induced oxidative stress and the mechanism responsible for these effects in hippocampal neuronal HT22 cells and in an animal model of forebrain ischemia using Tat-fused NOL3 protein (Tat-NOL3). Purified Tat-NOL3 protein transduced into the H2O2-exposed HT22 cells and inhibited the production of reactive oxygen species (ROS), DNA fragmentation and reduced mitochondrial membrane potential (ΔΨm). In addition, Tat-NOL3 prevented neuronal cell death through the regulation of apoptotic signaling pathways including Bax, Bcl-2, caspase-2, -3 and -8, PARP and p53. In addition, Tat-NOL3 protein transduced into the animal brains and significantly protected against neuronal cell death in the CA1 region of the hippocampus by regulating the activation of microglia and astrocytes. Taken together, these findings demonstrate that Tat-NOL3 protein protects against oxidative stress-induced neuronal cell death by regulating oxidative stress and by acting as an anti-apoptotic protein. Thus, we suggest that Tat-NOL3 represents a potential therapeutic agent for protection against ischemic brain injury. PMID:27221790

  6. Sensitization of acute lymphoblastic leukemia cells for LCL161-induced cell death by targeting redox homeostasis.

    PubMed

    Haß, Christina; Belz, Katharina; Schoeneberger, Hannah; Fulda, Simone

    2016-04-01

    Disturbed redox homeostasis with both elevated reactive oxygen species (ROS) levels and antioxidant defense mechanisms has been reported in acute lymphoblastic leukemia (ALL). We therefore hypothesized that inhibition of pathways responsible for ROS detoxification renders ALL cells more susceptible for cell death. Here, we report that pharmacological inhibitors of key pathways for the elimination of ROS, i.e. Erastin, buthionine sulfoximine (BSO) and Auranofin, sensitize ALL cells for cell death upon treatment with the Smac mimetic LCL161 that antagonizes Inhibitor of Apoptosis (IAP) proteins. Erastin, BSO or Auranofin significantly increase LCL161-induced cell death and also act in concert with LCL161 to profoundly suppress long-term clonogenic survival in several ALL cell lines. Erastin or BSO cooperates with LCL161 to stimulate ROS production and lipid peroxidation prior to cell death. ROS production and lipid peroxidation are required for this cotreatment-induced cell death, since ROS scavengers or pharmacological inhibition of lipid peroxidation provides significant protection against cell death. These results emphasize that inhibition of antioxidant defense mechanisms can serve as a potent approach to prime ALL cells for LCL161-induced cell death. PMID:26774450

  7. Pathophysiological role of different tubular epithelial cell death modes in acute kidney injury

    PubMed Central

    Sancho-Martínez, Sandra M.; López-Novoa, José M.; López-Hernández, Francisco J.

    2015-01-01

    The histological substrate of many forms of intrinsic acute kidney injury (AKI) has been classically attributed to tubular necrosis. However, more recent studies indicate that necrosis is not the main form of cell death in AKI and that other forms such as apoptosis, regulated necrosis (i.e. necroptosis and parthanatos), autophagic cell death and mitotic catastrophe, also participate in AKI and that their contribution depends on the cause and stage of AKI. Herein, we briefly summarize the main characteristics of the major types of cell death and we also critically review the existing evidence on the occurrence of different types of cell death reported in the most common experimental models of AKI and human specimens. We also discuss the pathophysiological mechanisms linking tubule epithelial cell death with reduced glomerular filtration, azotaemia and hydroelectrolytic imbalance. For instance, special relevance is given to the analysis of the inflammatory component of some forms of cell death over that of others, as an important and differential pathophysiological determinant. Finally, known molecular mechanisms and signalling pathways involved in each cell death type pose appropriate targets to specifically prevent or reverse AKI, provided that further knowledge of their participation and repercussion in each AKI syndrome is progressively increased in the near future. PMID:26413280

  8. Medical neglect death due to acute lymphoblastic leukaemia: an autopsy case report.

    PubMed

    Usumoto, Yosuke; Sameshima, Naomi; Tsuji, Akiko; Kudo, Keiko; Nishida, Naoki; Ikeda, Noriaki

    2014-12-01

    We report the case of 2-year-old girl who died of precursor B-cell acute lymphoblastic leukaemia (ALL), the most common cancer in children. She had no remarkable medical history. She was transferred to a hospital because of respiratory distress and died 4 hours after arrival. Two weeks before death, she had a fever of 39 degrees C, which subsided after the administration of a naturopathic herbal remedy. She developed jaundice 1 week before death, and her condition worsened on the day of death. Laboratory test results on admission showed a markedly elevated white blood cell count. Accordingly, the cause of death was suspected to be acute leukaemia. Forensic autopsy revealed the cause of death to be precursor B-cell ALL. With advancements in medical technology, the 5-year survival rate of children with ALL is nearly 90%. However, in this case, the deceased's parents preferred complementary and alternative medicine (i.e., naturopathy) to evidence-based medicine and had not taken her to a hospital for a medical check-up or immunisation since she was an infant. Thus, if she had received routine medical care, she would have a more than 60% chance of being alive 5 years after diagnosis. Therefore, we conclude that the parents should be accused of medical neglect regardless of their motives. PMID:25895240

  9. The ALIAmide palmitoylethanolamide and cannabinoids, but not anandamide, are protective in a delayed postglutamate paradigm of excitotoxic death in cerebellar granule neurons.

    PubMed Central

    Skaper, S D; Buriani, A; Dal Toso, R; Petrelli, L; Romanello, S; Facci, L; Leon, A

    1996-01-01

    The amino acid L-glutamate is a neurotransmitter that mediates fast neuronal excitation in a majority of synapses in the central nervous system. Glutamate stimulates both N-methyl-D-aspartate (NMDA) and non-NMDA receptors. While activation of NMDA receptors has been implicated in a variety of neurophysiologic processes, excessive NMDA receptor stimulation (excitotoxicity) is thought to be primarily responsible for neuronal injury in a wide variety of acute neurological disorders including hypoxia-ischemia, seizures, and trauma. Very little is known about endogenous molecules and mechanisms capable of modulating excitotoxic neuronal death. Saturated N-acylethanolamides like palmitoylethanolamide accumulate in ischemic tissues and are synthesized by neurons upon excitatory amino acid receptor activation. Here we report that palmitoylethanolamide, but not the cognate N-acylamide anandamide (the ethanolamide of arachidonic acid), protects cultured mouse cerebellar granule cells against glutamate toxicity in a delayed postagonist paradigm. Palmitoylethanolamide reduced this injury in a concentration-dependent manner and was maximally effective when added 15-min postglutamate. Cannabinoids, which like palmitoylethanolamide are functionally active at the peripheral cannabinoid receptor CB2 on mast cells, also prevented neuron loss in this delayed postglutamate model. Furthermore, the neuroprotective effects of palmitoylethanolamide, as well as that of the active cannabinoids, were efficiently antagonized by the candidate central cannabinoid receptor (CB1) agonist anandamide. Analogous pharmacological behaviors have been observed for palmitoylethanolamide (ALI-Amides) in downmodulating mast cell activation. Cerebellar granule cells expressed mRNA for CB1 and CB2 by in situ hybridization, while two cannabinoid binding sites were detected in cerebellar membranes. The results suggest that (i) non-CB1 cannabinoid receptors control, upon agonist binding, the downstream

  10. Gap Junction-Mediated Death of Retinal Neurons Is Connexin and Insult Specific: A Potential Target for Neuroprotection

    PubMed Central

    Akopian, Abram; Atlasz, Tamas; Pan, Feng; Wong, Sze; Zhang, Yi; Völgyi, Béla; Paul, David L.

    2014-01-01

    Secondary cell death via gap junctions (GJs) plays a role in the propagation of neuronal loss under a number of degenerative disorders. Here, we examined the role of GJs in neuronal death in the retina, which has arguably the most diverse expression of GJs in the CNS. Initially, we induced apoptotic death by injecting single retinal ganglion cells and glia with cytochrome C and found that this resulted in the loss of neighboring cells to which they were coupled via GJs. We next found that pharmacological blockade of GJs eradicated nearly all amacrine cell loss and reduced retinal ganglion cell loss by ∼70% after induction of either excitotoxic or ischemic insult conditions. These data indicate that the GJ-mediated secondary cell death was responsible for the death of most cells. Whereas genetic deletion of the GJ subunit Cx36 increased cell survivability by ∼50% under excitotoxic condition, cell loss in Cx45 knock-out mouse retinas was similar to that seen in wild-type mice. In contrast, ablation of Cx45 reduced neuronal loss by ∼50% under ischemic insult, but ablation of Cx36 offered no protection. Immunolabeling of the connexins showed differential changes in protein expression consistent with their differing roles in propagating death signals under the two insults. These data indicate that secondary cell death is mediated by different cohorts of GJs dependent on the connexins they express and the type of initial insult. Our results suggest that targeting specific connexins offers a novel therapeutic strategy to reduce progressive cell loss under different neurodegenerative conditions. PMID:25100592

  11. Carnosine decreased neuronal cell death through targeting glutamate system and astrocyte mitochondrial bioenergetics in cultured neuron/astrocyte exposed to OGD/recovery.

    PubMed

    Ouyang, Li; Tian, Yueyang; Bao, Yun; Xu, Huijuan; Cheng, Jiaoyan; Wang, Bingyu; Shen, Yao; Chen, Zhong; Lyu, Jianxin

    2016-06-01

    Previously, we showed that carnosine upregulated the expression level of glutamate transporter 1 (GLT-1), which has been recognized as an important participant in the astrocyte-neuron lactate shuttle (ANLS), with ischemic model in vitro and in vivo. This study was designed to investigate the protective effect of carnosine on neuron/astrocyte co-cultures exposed to OGD/recovery, and to explore whether the ANLS or any other mechanism contributes to carnosine-induced neuroprotection on neuron/astrocyte. Co-cultures were treated with carnosine and exposed to OGD/recovery. Cell death and the extracellular levels of glutamate and GABA were measured. The mitochondrial respiration and glycolysis were detected by Seahorse Bioscience XF96 Extracellular Flux Analyzer. Results showed that carnosine decreased neuronal cell death, increased extracellular GABA level, and abolished the increase in extracellular glutamate and reversed the mitochondrial energy metabolism disorder induced by OGD/recovery. Carnosine also upregulated the mRNA level of neuronal glutamate transporter EAAC1 at 2h after OGD. Dihydrokainate, a specific inhibitor of GLT-1, decreased glycolysis but it did not affect mitochondrial respiration of the cells, and it could not reverse the increase in mitochondrial OXPHOS induced by carnosine in the co-cultures. The levels of mRNAs for monocarboxylate transporter1, 4 (MCT1, 4), which were expressed in astrocytes, and MCT2, the main neuronal MCT, were significantly increased at the early stage of recovery. Carnosine only partly reversed the increased expression of astrocytic MCT1 and MCT4. These results suggest that regulating astrocytic energy metabolism and extracellular glutamate and GABA levels but not the ANLS are involved in the carnosine-induced neuroprotection. PMID:27040711

  12. The Anion Gap is a Predictive Clinical Marker for Death in Patients with Acute Pesticide Intoxication.

    PubMed

    Lee, Sun-Hyo; Park, Samel; Lee, Jung-Won; Hwang, Il-Woong; Moon, Hyung-Jun; Kim, Ki-Hwan; Park, Su-Yeon; Gil, Hyo-Wook; Hong, Sae-Yong

    2016-07-01

    Pesticide formulation includes solvents (methanol and xylene) and antifreeze (ethylene glycol) whose metabolites are anions such as formic acid, hippuric acid, and oxalate. However, the effect of the anion gap on clinical outcome in acute pesticide intoxication requires clarification. In this prospective study, we compared the anion gap and other parameters between surviving versus deceased patients with acute pesticide intoxication. The following parameters were assessed in 1,058 patients with acute pesticide intoxication: blood chemistry (blood urea nitrogen, creatinine, glucose, lactic acid, liver enzymes, albumin, globulin, and urate), urinalysis (ketone bodies), arterial blood gas analysis, electrolytes (Na(+), K(+), Cl(-) HCO3 (-), Ca(++)), pesticide field of use, class, and ingestion amount, clinical outcome (death rate, length of hospital stay, length of intensive care unit stay, and seriousness of toxic symptoms), and the calculated anion gap. Among the 481 patients with a high anion gap, 52.2% had a blood pH in the physiologic range, 35.8% had metabolic acidosis, and 12.1% had acidemia. Age, anion gap, pesticide field of use, pesticide class, seriousness of symptoms (all P < 0.001), and time lag after ingestion (P = 0.048) were significant risk factors for death in univariate analyses. Among these, age, anion gap, and pesticide class were significant risk factors for death in a multiple logistic regression analysis (P < 0.001). In conclusions, high anion gap is a significant risk factor for death, regardless of the accompanying acid-base balance status in patients with acute pesticide intoxication. PMID:27366016

  13. The Anion Gap is a Predictive Clinical Marker for Death in Patients with Acute Pesticide Intoxication

    PubMed Central

    2016-01-01

    Pesticide formulation includes solvents (methanol and xylene) and antifreeze (ethylene glycol) whose metabolites are anions such as formic acid, hippuric acid, and oxalate. However, the effect of the anion gap on clinical outcome in acute pesticide intoxication requires clarification. In this prospective study, we compared the anion gap and other parameters between surviving versus deceased patients with acute pesticide intoxication. The following parameters were assessed in 1,058 patients with acute pesticide intoxication: blood chemistry (blood urea nitrogen, creatinine, glucose, lactic acid, liver enzymes, albumin, globulin, and urate), urinalysis (ketone bodies), arterial blood gas analysis, electrolytes (Na+, K+, Cl- HCO3-, Ca++), pesticide field of use, class, and ingestion amount, clinical outcome (death rate, length of hospital stay, length of intensive care unit stay, and seriousness of toxic symptoms), and the calculated anion gap. Among the 481 patients with a high anion gap, 52.2% had a blood pH in the physiologic range, 35.8% had metabolic acidosis, and 12.1% had acidemia. Age, anion gap, pesticide field of use, pesticide class, seriousness of symptoms (all P < 0.001), and time lag after ingestion (P = 0.048) were significant risk factors for death in univariate analyses. Among these, age, anion gap, and pesticide class were significant risk factors for death in a multiple logistic regression analysis (P < 0.001). In conclusions, high anion gap is a significant risk factor for death, regardless of the accompanying acid-base balance status in patients with acute pesticide intoxication. PMID:27366016

  14. Excision of DNA loop domains as a common step in caspase-dependent and -independent types of neuronal cell death.

    PubMed

    Bezvenyuk, Z; Salminen, A; Solovyan, V

    2000-09-30

    Treatment of rat cerebellar granule neurons with the phosphatase inhibitor, okadaic acid (OKA) or the excitatory neurotransmitter, L-glutamate, resulted in progressive cell death associated with apoptotic-like changes in nuclear morphology. The OKA-induced neurotoxicity was accompanied by the activation of caspase-3 (ICE-related cysteine protease) and the development of an oligonucleosomal DNA ladder, whereas neither activation of caspase-1, -2, -3, -5, or -9, nor internucleosomal DNA fragmentation accompanied L-glutamate-induced neurotoxicity. At the same time, both OKA and L-glutamate induced a similar pattern of nuclear DNA disintegration into high molecular weight (HMW)-DNA fragments of about 50-100 kb, which are widely believed to originate from the excision of DNA loop domains. Z-DEVD-fmk, a specific caspase-3 inhibitor, as well as a general caspase inhibitor, z-VAD-fmk, inhibited both the internucleosomal- and HMW-DNA fragmentation in OKA-treated neurons. However neither z-DEVD-fmk nor z-VAD-fmk had any obvious inhibitory effect on the formation of HMW-DNA fragments induced by L-glutamate. The results indicate that the formation of the HMW-DNA fragments in cerebellar granule neurons accompanies both caspase-dependent and -independent types of cell death, indicative of multiple mechanisms in the regulation of excision of DNA loop domains during neuronal cell death. PMID:11000492

  15. Selective Inhibition of MAPK Phosphatases by Zinc Accounts for ERK1/2-dependent Oxidative Neuronal Cell Death

    PubMed Central

    Ho, Yeung; Samarasinghe, Ranmal; Knoch, Megan E.; Lewis, Marcia; Aizenman, Elias; DeFranco, Donald B.

    2008-01-01

    Oxidative stress induced by glutathione depletion in the mouse HT22 neuroblastoma cell line and embryonic rat immature cortical neurons causes a delayed, sustained activation of extracellular signal-regulated kinases-1/2 (ERK1/2), which is required for cell death. This sustained activation of ERK1/2 is mediated primarily by a selective inhibition of distinct ERK1/2-directed phosphatases either by enhanced degradation (i.e. for Mitogen activated protein kinase [MAPK] Phosphatase-1) or as shown here by reductions in enzymatic activity (i.e. for Protein Phosphatase type 2A [PP-2A]). The inhibition of ERK1/2 phosphatases in HT22 cells and immature neurons subjected to glutathione depletion results from oxidative stress as phosphatase activity is restored in cells treated with the antioxidant butylated hydroxyanisole (BHA). This leads to reduced ERK1/2 activation and neuroprotection. Furthermore, an increase in free intracellular zinc that accompanies glutathione-induced oxidative stress in HT22 cells and immature neurons contributes to selective inhibition of ERK1/2 phosphatase activity and cell death. Finally, ERK1/2 also functions to maintain elevated levels of zinc. Thus the elevation of intracellular zinc within neurons subjected to oxidative stress can trigger a robust positive feedback loop operating through activated ERK1/2 that rapidly sets into motion a zinc-dependent pathway of cell death. PMID:18635668

  16. Target-related and intrinsic neuronal death in Lurcher mutant mice are both mediated by caspase-3 activation.

    PubMed

    Selimi, F; Doughty, M; Delhaye-Bouchaud, N; Mariani, J

    2000-02-01

    The Lurcher (Lc) mutation in the delta2 glutamate receptor gene leads to the presence of a constitutive inward current in the cerebellar Purkinje cells of Lurcher heterozygous mice and to the postnatal degeneration of these neurons. In addition, cerebellar granule cells and olivary neurons of Lc/+ mice die as an indirect effect of the mutation after the loss of their target Purkinje cells. The apoptotic nature of Lc/+ Purkinje cell death remains controversial. To address this question, we studied the involvement of caspase-3, a key effector of apoptosis, in the neurodegenerative processes occurring in Lc/+ cerebellum. Several antibodies recognizing different regions of caspase-3 were used in immunoblotting and immunohistochemical experiments. We demonstrate that pro-caspase-3 is specifically upregulated in the dying Lc/+ Purkinje cells, but not in granule cells and olivary neurons, suggesting that different death-inducing signals trigger variant apoptotic pathways in the CNS. The subcellular localization of pro-caspase-3 was shown to be cytoplasmic and mitochondrial. Active caspase-3 as well as DNA fragmentation was found in numerous granule cells and some Purkinje cells of the Lc/+ cerebellum. Thus, caspase-3 activation is involved in both the direct and indirect neuronal death induced by the Lurcher mutation, strongly supporting the idea that the Lc/+ Purkinje cell dies by apoptosis. PMID:10648704

  17. 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

  18. Phenylpropenoic Acid Glucoside from Rooibos Protects Pancreatic Beta Cells against Cell Death Induced by Acute Injury

    PubMed Central

    Himpe, Eddy; Cunha, Daniel A.; Song, Imane; Bugliani, Marco; Marchetti, Piero; Cnop, Miriam; Bouwens, Luc

    2016-01-01

    Objective Previous studies demonstrated that a phenylpropenoic acid glucoside (PPAG) from rooibos (Aspalathus linearis) extract had anti-hyperglycemic activity and significant protective effects on the pancreatic beta cell mass in a chronic diet-induced diabetes model. The present study evaluated the cytoprotective effect of the phytochemical on beta cells exposed to acute cell stress. Methods Synthetically prepared PPAG was administered orally in mice treated with a single dose of streptozotocin to acutely induce beta cell death and hyperglycemia. Its effect was assessed on beta cell mass, proliferation and apoptotic cell death. Its cytoprotective effect was also studied in vitro on INS-1E beta cells and on human pancreatic islet cells. Results Treatment with the phytochemical PPAG protected beta cells during the first days after the insult against apoptotic cell death, as evidenced by TUNEL staining, and prevented loss of expression of anti-apoptotic protein BCL2 in vivo. In vitro, PPAG protected INS-1E beta cells from streptozotocin-induced apoptosis and necrosis in a BCL2-dependent and independent way, respectively, depending on glucose concentration. PPAG also protected human pancreatic islet cells against the cytotoxic action of the fatty acid palmitate. Conclusions These findings show the potential use of PPAG as phytomedicine which protects the beta cell mass exposed to acute diabetogenic stress. PMID:27299564

  19. Discovery of a novel neuroprotectant, BHDPC, that protects against MPP+/MPTP-induced neuronal death in multiple experimental models.

    PubMed

    Chong, Cheong-Meng; Ma, Dan; Zhao, Chao; Franklin, Robin J M; Zhou, Zhong-Yan; Ai, Nana; Li, Chuwen; Yu, Huidong; Hou, Tingjun; Sa, Fei; Lee, Simon Ming-Yuen

    2015-12-01

    Progressive degeneration and death of neurons are main causes of neurodegenerative disorders such as Parkinson's disease and Alzheimer's disease. Although some current medicines may temporarily improve their symptoms, no treatments can slow or halt the progression of neuronal death. In this study, a pyrimidine derivative, benzyl 7-(4-hydroxy-3-methoxyphenyl)-5-methyl-4,7-dihydrotetrazolo[1,5-a]pyrimidine-6-carboxylate (BHDPC), was found to attenuate dramatically the MPTP-induced death of dopaminergic neurons and improve behavior movement deficiency in zebrafish, supporting its potential neuroprotective activity in vivo. Further study in rat organotypic cerebellar cultures indicated that BHDPC was able to suppress MPP(+)-induced cell death of brain tissue slices ex vivo. The protective effect of BHDPC against MPP(+) toxicity was also effective in human neuroblastoma SH-SY5Y cells through restoring abnormal changes in mitochondrial membrane potential and numerous apoptotic regulators. Western blotting analysis indicated that BHDPC was able to activate PKA/CREB survival signaling and further up-regulate Bcl2 expression. However, BHDPC failed to suppress MPP(+)-induced cytotoxicity and the increase of caspase 3 activity in the presence of the PKA inhibitor H89. Taken together, these results suggest that BHDPC is a potential neuroprotectant with prosurvival effects in multiple models of neurodegenerative disease in vitro, ex vivo, and in vivo. PMID:26415025

  20. 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

  1. 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

  2. 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

  3. XBP1 mitigates aminoglycoside-induced endoplasmic reticulum stress and neuronal cell death

    PubMed Central

    Oishi, N; Duscha, S; Boukari, H; Meyer, M; Xie, J; Wei, G; Schrepfer, T; Roschitzki, B; Boettger, E C; Schacht, J

    2015-01-01

    Here we study links between aminoglycoside-induced mistranslation, protein misfolding and neuropathy. We demonstrate that aminoglycosides induce misreading in mammalian cells and assess endoplasmic reticulum (ER) stress and unfolded protein response (UPR) pathways. Genome-wide transcriptome and proteome analyses revealed upregulation of genes related to protein folding and degradation. Quantitative PCR confirmed induction of UPR markers including C/EBP homologous protein, glucose-regulated protein 94, binding immunoglobulin protein and X-box binding protein-1 (XBP1) mRNA splicing, which is crucial for UPR activation. We studied the effect of a compromised UPR on aminoglycoside ototoxicity in haploinsufficient XBP1 (XBP1+/−) mice. Intra-tympanic aminoglycoside treatment caused high-frequency hearing loss in XBP1+/− mice but not in wild-type littermates. Densities of spiral ganglion cells and synaptic ribbons were decreased in gentamicin-treated XBP1+/− mice, while sensory cells were preserved. Co-injection of the chemical chaperone tauroursodeoxycholic acid attenuated hearing loss. These results suggest that aminoglycoside-induced ER stress and cell death in spiral ganglion neurons is mitigated by XBP1, masking aminoglycoside neurotoxicity at the organismal level. PMID:25973683

  4. CCL11 enhances excitotoxic neuronal death by producing reactive oxygen species in microglia.

    PubMed

    Parajuli, Bijay; Horiuchi, Hiroshi; Mizuno, Tetsuya; Takeuchi, Hideyuki; Suzumura, Akio

    2015-12-01

    The chemokine CCL11 (also known as eotaxin-1) is a potent eosinophil chemoattractant that mediates allergic diseases such as asthma, atopic dermatitis, and inflammatory bowel diseases. Previous studies demonstrated that concentrations of CCL11 are elevated in the sera and cerebrospinal fluids (CSF) of patients with neuroinflammatory disorders, including multiple sclerosis. Moreover, the levels of CCL11 in plasma and CSF increase with age, and CCL11 suppresses adult neurogenesis in the central nervous system (CNS), resulting in memory impairment. However, the precise source and function of CCL11 in the CNS are not fully understood. In this study, we found that activated astrocytes release CCL11, whereas microglia predominantly express the CCL11 receptor. CCL11 significantly promoted the migration of microglia, and induced microglial production of reactive oxygen species by upregulating nicotinamide adenine dinucleotide phosphate-oxidase 1 (NOX1), thereby promoting excitotoxic neuronal death. These effects were reversed by inhibition of NOX1. Our findings suggest that CCL11 released from activated astrocytes triggers oxidative stress via microglial NOX1 activation and potentiates glutamate-mediated neurotoxicity, which may be involved in the pathogenesis of various neurological disorders. PMID:26184677

  5. Hijacking microglial glutathione by inorganic arsenic impels bystander death of immature neurons through extracellular cystine/glutamate imbalance

    PubMed Central

    Singh, Vikas; Gera, Ruchi; Kushwaha, Rajesh; Sharma, Anuj Kumar; Patnaik, Satyakam; Ghosh, Debabrata

    2016-01-01

    Arsenic-induced altered microglial activity leads to neuronal death, but the causative mechanism remains unclear. The present study showed, arsenic-exposed (10 μM) microglial (N9) culture supernatant induced bystander death of neuro-2a (N2a), which was further validated with primary microglia and immature neuronal cultures. Results indicated that arsenic-induced GSH synthesis by N9 unfavorably modified the extracellular milieu for N2a by lowering cystine and increasing glutamate concentration. Similar result was observed in N9-N2a co-culture. Co-exposure of arsenic and 250 μM glutamate, less than the level (265 μM) detected in arsenic-exposed N9 culture supernatant, compromised N2a viability which was rescued by cystine supplementation. Therefore, microglia executes bystander N2a death by competitive inhibition of system Xc- (xCT) through extracellular cystine/glutamate imbalance. We confirmed the role of xCT in mediating bystander N2a death by siRNA inhibition studies. Ex-vivo primary microglia culture supernatant from gestationally exposed mice measured to contain lower cystine and higher glutamate compared to control and N-acetyl cysteine co-treated group. Immunofluorescence staining of brain cryosections from treated group showed more dead immature neurons with no such effect on microglia. Collectively, we showed, in presence of arsenic microglia alters cystine/glutamate balance through xCT in extracellular milieu leading to bystander death of immature neurons. PMID:27477106

  6. Hijacking microglial glutathione by inorganic arsenic impels bystander death of immature neurons through extracellular cystine/glutamate imbalance.

    PubMed

    Singh, Vikas; Gera, Ruchi; Kushwaha, Rajesh; Sharma, Anuj Kumar; Patnaik, Satyakam; Ghosh, Debabrata

    2016-01-01

    Arsenic-induced altered microglial activity leads to neuronal death, but the causative mechanism remains unclear. The present study showed, arsenic-exposed (10 μM) microglial (N9) culture supernatant induced bystander death of neuro-2a (N2a), which was further validated with primary microglia and immature neuronal cultures. Results indicated that arsenic-induced GSH synthesis by N9 unfavorably modified the extracellular milieu for N2a by lowering cystine and increasing glutamate concentration. Similar result was observed in N9-N2a co-culture. Co-exposure of arsenic and 250 μM glutamate, less than the level (265 μM) detected in arsenic-exposed N9 culture supernatant, compromised N2a viability which was rescued by cystine supplementation. Therefore, microglia executes bystander N2a death by competitive inhibition of system Xc(-) (xCT) through extracellular cystine/glutamate imbalance. We confirmed the role of xCT in mediating bystander N2a death by siRNA inhibition studies. Ex-vivo primary microglia culture supernatant from gestationally exposed mice measured to contain lower cystine and higher glutamate compared to control and N-acetyl cysteine co-treated group. Immunofluorescence staining of brain cryosections from treated group showed more dead immature neurons with no such effect on microglia. Collectively, we showed, in presence of arsenic microglia alters cystine/glutamate balance through xCT in extracellular milieu leading to bystander death of immature neurons. PMID:27477106

  7. Acute poisonings and sudden deaths in Crete: a five-year review (1991-1996).

    PubMed

    Christakis-Hampsas, M; Tutudakis, M; Tsatsakis, A M; Assithianakis, P; Alegakis, A; Katonis, P G; Michalodimitrakis, E N

    1998-08-01

    Fatal and non-fatal acute poisonings and other sudden deaths examined in the Toxicology Laboratory of University Hospital of Iraklion, Crete, from 1991 to 1996 mainly involved the abuse of drugs (heroin, flunitrazepam and other psychoactive substances), accidental poisonings or suicide attempts with pesticides (carbamates, organophosphates, paraquat), other chemicals (cyanide salts, paint thinner, chlorine), traffic accidents, drownings and violent deaths (gunshots). Many of the cases were related to poisonous gases or volatiles (carbon monoxide, methylbromide). Fatalities due to alcohol and methylene-dioxy-ethyl amphetamine were also examined. Amphetamine and alcohol-related deaths due to drowning were more recent. A significant number of cases were related to the accidental ingestion of alcohol, drugs or suicide attempts by children. Some of the cases were treated successfully in various Cretan hospitals, while others had fatal outcomes due to late hospital admission. PMID:9682411

  8. 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

  9. 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

  10. The maintenance of specific aspects of neuronal function and behavior is dependent on programmed cell death of adult-generated neurons in the dentate gyrus

    PubMed Central

    Kim, Woon Ryoung; Park, Ok-hee; Choi, Sukwoo; Choi, Se-Young; Park, Soon Kwon; Lee, Kea Joo; Rhyu, Im Joo; Kim, Hyun; Lee, Yeon Kyung; Kim, Hyun Taek; Oppenheim, Ronald W; Sun, Woong

    2009-01-01

    A considerable number of new neurons are generated daily in the dentate gyrus (DG) of the adult hippocampus, but only a subset of these survive, as many adult-generated neurons undergo programmed cell death (PCD). However, the significance of PCD in the adult brain for the functionality of DG circuits is not known. Here we examined the electrophysiological and behavioral characteristics of Bax-KO mice in which PCD of post-mitotic neurons is prevented. The continuous increase in DG cell numbers in Bax-KO mice, resulted in the readjustment of afferent and efferent synaptic connections, represented by age-dependent reductions in the dendritic arborization of DG neurons and in the synaptic contact ratio of mossy fibers (MF) with CA3 dendritic spines. These neuroanatomical changes were associated with reductions in synaptic transmission and reduced performance in a contextual fear memory task in 6-month old Bax-KO mice. These results suggest that the elimination of excess DG neurons via Bax-dependent PCD in the adult brain is required for the normal organization and function of the hippocampus. PMID:19519627

  11. The Ketone Body, β-Hydroxybutyrate Stimulates the Autophagic Flux and Prevents Neuronal Death Induced by Glucose Deprivation in Cortical Cultured Neurons.

    PubMed

    Camberos-Luna, Lucy; Gerónimo-Olvera, Cristian; Montiel, Teresa; Rincon-Heredia, Ruth; Massieu, Lourdes

    2016-03-01

    Glucose is the major energy substrate in brain, however, during ketogenesis induced by starvation or prolonged hypoglycemia, the ketone bodies (KB), acetoacetate and β-hydroxybutyrate (BHB) can substitute for glucose. KB improve neuronal survival in diverse injury models, but the mechanisms by which KB prevent neuronal damage are still not well understood. In the present study we have investigated whether protection by the D isomer of BHB (D-BHB) against neuronal death induced by glucose deprivation (GD), is related to autophagy. Autophagy is a lysosomal-dependent degradation process activated during nutritional stress, which leads to the digestion of damaged proteins and organelles providing energy for cell survival. Results show that autophagy is activated in cortical cultured neurons during GD, as indicated by the increase in the levels of the lipidated form of the microtubule associated protein light chain 3 (LC3-II), and the number of autophagic vesicles. At early phases of glucose reintroduction (GR), the levels of p62 declined suggesting that the degradation of the autophagolysosomal content takes place at this time. In cultures exposed to GD and GR in the presence of D-BHB, the levels of LC3-II and p62 rapidly declined and remained low during GR, suggesting that the KB stimulates the autophagic flux preventing autophagosome accumulation and improving neuronal survival. PMID:26303508

  12. 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

  13. Protective Role of STAT3 in NMDA and Glutamate-Induced Neuronal Death: Negative Regulatory Effect of SOCS3

    PubMed Central

    Park, Keun W.; Nozell, Susan E.; Benveniste, Etty N.

    2012-01-01

    The present study investigates the involvement of the IL-6 family of cytokines, activation of the transcription factor Signal Transducer and Activator of Transcription-3 (STAT3), and the role of Suppressor Of Cytokine Signaling-3 (SOCS3) in regulating excitotoxic neuronal death in vitro. Biochemical evidence demonstrates that in primary cortical neurons and SH-SY5Y neuroblastoma cells, IL-6 cytokine family members, OSM and IL-6 plus the soluble IL-6R (IL-6/R), prevent NMDA and glutamate-induced neuronal toxicity. As well, OSM and IL-6/R induce tyrosine and serine phosphorylation of STAT3 in primary cortical neurons and SH-SY5Y cells. Studies using Pyridine 6 (P6), a pan-JAK inhibitor, demonstrate that the protective effect of OSM and IL-6/R on neuronal death is mediated by the JAK/STAT3 signaling pathway. In parallel to STAT3 phosphorylation, OSM and IL-6/R induce SOCS3 expression at the mRNA and protein level. P6 treatment inhibits SOCS3 expression, indicating that STAT3 is required for OSM and IL-6/R-induced SOCS3 expression. Lentiviral delivery of SOCS3, an inhibitor of STAT3 signaling, into primary neurons and SH-SY5Y cells inhibits OSM and IL-6/R-induced phosphorylation of STAT3, and also reverses the protective effect of OSM and IL-6/R on NMDA and glutamate-induced neurotoxicity in primary cortical neurons. In addition, treatment with IL-6 cytokines increases expression of the anti-apoptotic protein Bcl-xL and induces activation of the Akt signaling pathway, which are also negatively regulated by SOCS3 expression. Thus, IL-6/R and OSM-induced SOCS3 expression may be an important factor limiting the neuroprotective effects of activated STAT3 against NMDA and glutamate-induced neurotoxicity. PMID:23226414

  14. Fragile X Mental Retardation Protein is Required for Programmed Cell Death and Clearance of Developmentally-Transient Peptidergic Neurons

    PubMed Central

    Gatto, Cheryl L.; Broadie, Kendal

    2011-01-01

    Fragile X syndrome (FXS), caused by loss of fragile X mental retardation 1 (FMR1) gene function, is the most common heritable cause of intellectual disability and autism spectrum disorders. The FMR1 product (FMRP) is an RNA-binding protein best established to function in activity-dependent modulation of synaptic connections. In the Drosophila FXS disease model, loss of functionally-conserved dFMRP causes synaptic overgrowth and overelaboration in pigment dispersing factor (PDF) peptidergic neurons in the adult brain. Here, we identify a very different component of PDF neuron misregulation in dfmr1 mutants: the aberrant retention of normally developmentally-transient PDF tritocerebral (PDF-TRI) neurons. In wild-type animals, PDF-TRI neurons in the central brain undergo programmed cell death and complete, processive clearance within days of eclosion. In the absence of dFMRP, a defective apoptotic program leads to constitutive maintenance of these peptidergic neurons. We tested whether this apoptotic defect is circuit-specific by examining crustacean cardioactive peptide (CCAP) and bursicon circuits, which are similarly developmentally-transient and normally eliminated immediately post-eclosion. In dfmr1 null mutants, CCAP/bursicon neurons also exhibit significantly delayed clearance dynamics, but are subsequently eliminated from the nervous system, in contrast to the fully persistent PDF-TRI neurons. Thus, the requirement of dFMRP for the retention of transitory peptidergic neurons shows evident circuit specificity. The novel defect of impaired apoptosis and aberrant neuron persistence in the Drosophila FXS model suggests an entirely new level of “pruning” dysfunction may contribute to the FXS disease state. PMID:21596027

  15. GSK-3β-induced Tau pathology drives hippocampal neuronal cell death in Huntington's disease: involvement of astrocyte–neuron interactions

    PubMed Central

    L'Episcopo, F; Drouin-Ouellet, J; Tirolo, C; Pulvirenti, A; Giugno, R; Testa, N; Caniglia, S; Serapide, M F; Cisbani, G; Barker, R A; Cicchetti, F; Marchetti, B

    2016-01-01

    Glycogen synthase kinase-3β (GSK-3β) has emerged as a critical factor in several pathways involved in hippocampal neuronal maintenance and function. In Huntington's disease (HD), there are early hippocampal deficits both in patients and transgenic mouse models, which prompted us to investigate whether disease-specific changes in GSK-3β expression may underlie these abnormalities. Thirty-three postmortem hippocampal samples from HD patients (neuropathological grades 2–4) and age- and sex-matched normal control cases were analyzed using real-time quantitative reverse transcription PCRs (qPCRs) and immunohistochemistry. In vitro and in vivo studies looking at hippocampal pathology and GSK-3β were also undertaken in transgenic R6/2 and wild-type mice. We identified a disease and stage-dependent upregulation of GSK-3β mRNA and protein levels in the HD hippocampus, with the active isoform pGSK-3β-Tyr216 being strongly expressed in dentate gyrus (DG) neurons and astrocytes at a time when phosphorylation of Tau at the AT8 epitope was also present in these same neurons. This upregulation of pGSK-3β-Tyr216 was also found in the R6/2 hippocampus in vivo and linked to the increased vulnerability of primary hippocampal neurons in vitro. In addition, the increased expression of GSK-3β in the astrocytes of R6/2 mice appeared to be the main driver of Tau phosphorylation and caspase3 activation-induced neuronal death, at least in part via an exacerbated production of major proinflammatory mediators. This stage-dependent overactivation of GSK-3β in HD-affected hippocampal neurons and astrocytes therefore points to GSK-3β as being a critical factor in the pathological development of this condition. As such, therapeutic targeting of this pathway may help ameliorate neuronal dysfunction in HD. PMID:27124580

  16. GSK-3β-induced Tau pathology drives hippocampal neuronal cell death in Huntington's disease: involvement of astrocyte-neuron interactions.

    PubMed

    L'Episcopo, F; Drouin-Ouellet, J; Tirolo, C; Pulvirenti, A; Giugno, R; Testa, N; Caniglia, S; Serapide, M F; Cisbani, G; Barker, R A; Cicchetti, F; Marchetti, B

    2016-01-01

    Glycogen synthase kinase-3β (GSK-3β) has emerged as a critical factor in several pathways involved in hippocampal neuronal maintenance and function. In Huntington's disease (HD), there are early hippocampal deficits both in patients and transgenic mouse models, which prompted us to investigate whether disease-specific changes in GSK-3β expression may underlie these abnormalities. Thirty-three postmortem hippocampal samples from HD patients (neuropathological grades 2-4) and age- and sex-matched normal control cases were analyzed using real-time quantitative reverse transcription PCRs (qPCRs) and immunohistochemistry. In vitro and in vivo studies looking at hippocampal pathology and GSK-3β were also undertaken in transgenic R6/2 and wild-type mice. We identified a disease and stage-dependent upregulation of GSK-3β mRNA and protein levels in the HD hippocampus, with the active isoform pGSK-3β-Tyr(216) being strongly expressed in dentate gyrus (DG) neurons and astrocytes at a time when phosphorylation of Tau at the AT8 epitope was also present in these same neurons. This upregulation of pGSK-3β-Tyr(216) was also found in the R6/2 hippocampus in vivo and linked to the increased vulnerability of primary hippocampal neurons in vitro. In addition, the increased expression of GSK-3β in the astrocytes of R6/2 mice appeared to be the main driver of Tau phosphorylation and caspase3 activation-induced neuronal death, at least in part via an exacerbated production of major proinflammatory mediators. This stage-dependent overactivation of GSK-3β in HD-affected hippocampal neurons and astrocytes therefore points to GSK-3β as being a critical factor in the pathological development of this condition. As such, therapeutic targeting of this pathway may help ameliorate neuronal dysfunction in HD. PMID:27124580

  17. 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

  18. 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

  19. mTOR inhibition by everolimus in childhood acute lymphoblastic leukemia induces caspase-independent cell death.

    PubMed

    Baraz, Rana; Cisterne, Adam; Saunders, Philip O; Hewson, John; Thien, Marilyn; Weiss, Jocelyn; Basnett, Jordan; Bradstock, Kenneth F; Bendall, Linda J

    2014-01-01

    Increasingly, anti-cancer medications are being reported to induce cell death mechanisms other than apoptosis. Activating alternate death mechanisms introduces the potential to kill cells that have defects in their apoptotic machinery, as is commonly observed in cancer cells, including in hematological malignancies. We, and others, have previously reported that the mTOR inhibitor everolimus has pre-clinical efficacy and induces caspase-independent cell death in acute lymphoblastic leukemia cells. Furthermore, everolimus is currently in clinical trial for acute lymphoblastic leukemia. Here we characterize the death mechanism activated by everolimus in acute lymphoblastic leukemia cells. We find that cell death is caspase-independent and lacks the morphology associated with apoptosis. Although mitochondrial depolarization is an early event, permeabilization of the outer mitochondrial membrane only occurs after cell death has occurred. While morphological and biochemical evidence shows that autophagy is clearly present it is not responsible for the observed cell death. There are a number of features consistent with paraptosis including morphology, caspase-independence, and the requirement for new protein synthesis. However in contrast to some reports of paraptosis, the activation of JNK signaling was not required for everolimus-induced cell death. Overall in acute lymphoblastic leukemia cells everolimus induces a cell death that resembles paraptosis. PMID:25014496

  20. mTOR Inhibition by Everolimus in Childhood Acute Lymphoblastic Leukemia Induces Caspase-Independent Cell Death

    PubMed Central

    Baraz, Rana; Cisterne, Adam; Saunders, Philip O.; Hewson, John; Thien, Marilyn; Weiss, Jocelyn; Basnett, Jordan; Bradstock, Kenneth F.; Bendall, Linda J.

    2014-01-01

    Increasingly, anti-cancer medications are being reported to induce cell death mechanisms other than apoptosis. Activating alternate death mechanisms introduces the potential to kill cells that have defects in their apoptotic machinery, as is commonly observed in cancer cells, including in hematological malignancies. We, and others, have previously reported that the mTOR inhibitor everolimus has pre-clinical efficacy and induces caspase-independent cell death in acute lymphoblastic leukemia cells. Furthermore, everolimus is currently in clinical trial for acute lymphoblastic leukemia. Here we characterize the death mechanism activated by everolimus in acute lymphoblastic leukemia cells. We find that cell death is caspase-independent and lacks the morphology associated with apoptosis. Although mitochondrial depolarization is an early event, permeabilization of the outer mitochondrial membrane only occurs after cell death has occurred. While morphological and biochemical evidence shows that autophagy is clearly present it is not responsible for the observed cell death. There are a number of features consistent with paraptosis including morphology, caspase-independence, and the requirement for new protein synthesis. However in contrast to some reports of paraptosis, the activation of JNK signaling was not required for everolimus-induced cell death. Overall in acute lymphoblastic leukemia cells everolimus induces a cell death that resembles paraptosis. PMID:25014496

  1. Genes Involved in the Balance between Neuronal Survival and Death during Inflammation

    PubMed Central

    Glezer, Isaias; Chernomoretz, Ariel; David, Samuel; Plante, Marie-Michèle; Rivest, Serge

    2007-01-01

    Glucocorticoids are potent regulators of the innate immune response, and alteration in this inhibitory feedback has detrimental consequences for the neural tissue. This study profiled and investigated functionally candidate genes mediating this switch between cell survival and death during an acute inflammatory reaction subsequent to the absence of glucocorticoid signaling. Oligonucleotide microarray analysis revealed that following lipopolysaccharide (LPS) intracerebral administration at striatum level, more modulated genes presented transcription impairment than exacerbation upon glucocorticoid receptor blockage. Among impaired genes we identified ceruloplasmin (Cp), which plays a key role in iron metabolism and is implicated in a neurodegenative disease. Microglial and endothelial induction of Cp is a natural neuroprotective mechanism during inflammation, because Cp-deficient mice exhibited increased iron accumulation and demyelination when exposed to LPS and neurovascular reactivity to pneumococcal meningitis. This study has identified genes that can play a critical role in programming the innate immune response, helping to clarify the mechanisms leading to protection or damage during inflammatory conditions in the CNS. PMID:17375196

  2. Glycogen synthase kinase 3beta (GSK3beta) mediates 6-hydroxydopamine-induced neuronal death.

    PubMed

    Chen, Gang; Bower, Kimberly A; Ma, Cuiling; Fang, Shengyun; Thiele, Carol J; Luo, Jia

    2004-07-01

    The causes of sporadic Parkinson's disease (PD) are poorly understood. 6-Hydroxydopamine (6-OHDA), a PD mimetic, is widely used to model this neurodegenerative disorder in vitro and in vivo; however, the underlying mechanisms remain incompletely elucidated. We demonstrate here that 6-OHDA evoked endoplasmic reticulum (ER) stress, which was characterized by an up-regulation in the expression of GRP78 and GADD153 (Chop), cleavage of procaspase-12, and phosphorylation of eukaryotic initiation factor-2 alpha in a human dopaminergic neuronal cell line (SH-SY5Y) and cultured rat cerebellar granule neurons (CGNs). Glycogen synthase kinase-3 beta (GSK3beta) responds to ER stress, and its activity is regulated by phosphorylation. 6-OHDA significantly inhibited phosphorylation of GSK3beta at Ser9, whereas it induced hyperphosphorylation of Tyr216 with little effect on GSK3beta expression in SH-SY5Y cells and PC12 cells (a rat dopamine cell line), as well as CGNs. Furthermore, 6-OHDA decreased the expression of cyclin D1, a substrate of GSK3beta, and dephosphorylated Akt, the upstream signaling component of GSK3beta. Protein phosphatase 2A (PP2A), an ER stress-responsive phosphatase, was involved in 6-OHDA-induced GSK3beta dephosphorylation (Ser9). Blocking GSK3beta activity by selective inhibitors (lithium, TDZD-8, and L803-mts) prevented 6-OHDA-induced cleavage of caspase-3 and poly(ADP-ribose) polymerase (PARP), DNA fragmentations and cell death. With a tetracycline (Tet)-controlled TrkB inducible system, we demonstrated that activation of TrkB in SH-SY5Y cells alleviated 6-OHDA-induced GSK3beta dephosphorylation (Ser9) and ameliorated 6-OHDA neurotoxicity. TrkB activation also protected CGNs against 6-OHDA-induced damage. Although antioxidants also offered neuroprotection, they had little effect on 6-OHDA-induced GSK3beta activation. These results suggest that GSK3beta is a critical intermediate in pro-apoptotic signaling cascades that are associated with

  3. Dieckol Attenuates Microglia-mediated Neuronal Cell Death via ERK, Akt and NADPH Oxidase-mediated Pathways.

    PubMed

    Cui, Yanji; Park, Jee-Yun; Wu, Jinji; Lee, Ji Hyung; Yang, Yoon-Sil; Kang, Moon-Seok; Jung, Sung-Cherl; Park, Joo Min; Yoo, Eun-Sook; Kim, Seong-Ho; Ahn Jo, Sangmee; Suk, Kyoungho; Eun, Su-Yong

    2015-05-01

    Excessive microglial activation and subsequent neuroinflammation lead to synaptic loss and dysfunction as well as neuronal cell death, which are involved in the pathogenesis and progression of several neurodegenerative diseases. Thus, the regulation of microglial activation has been evaluated as effective therapeutic strategies. Although dieckol (DEK), one of the phlorotannins isolated from marine brown alga Ecklonia cava, has been previously reported to inhibit microglial activation, the molecular mechanism is still unclear. Therefore, we investigated here molecular mechanism of DEK via extracellular signal-regulated kinase (ERK), Akt and nicotinamide adenine dinuclelotide phosphate (NADPH) oxidase-mediated pathways. In addition, the neuroprotective mechanism of DEK was investigated in microglia-mediated neurotoxicity models such as neuron-microglia co-culture and microglial conditioned media system. Our results demonstrated that treatment of anti-oxidant DEK potently suppressed phosphorylation of ERK in lipopolysaccharide (LPS, 1 µg/ml)-stimulated BV-2 microglia. In addition, DEK markedly attenuated Akt phosphorylation and increased expression of gp91 (phox) , which is the catalytic component of NADPH oxidase complex responsible for microglial reactive oxygen species (ROS) generation. Finally, DEK significantly attenuated neuronal cell death that is induced by treatment of microglial conditioned media containing neurotoxic secretary molecules. These neuroprotective effects of DEK were also confirmed in a neuron-microglia co-culture system using enhanced green fluorescent protein (EGFP)-transfected B35 neuroblastoma cell line. Taken together, these results suggest that DEK suppresses excessive microglial activation and microglia-mediated neuronal cell death via downregulation of ERK, Akt and NADPH oxidase-mediated pathways. PMID:25954126

  4. Dieckol Attenuates Microglia-mediated Neuronal Cell Death via ERK, Akt and NADPH Oxidase-mediated Pathways

    PubMed Central

    Cui, Yanji; Park, Jee-Yun; Wu, Jinji; Lee, Ji Hyung; Yang, Yoon-Sil; Kang, Moon-Seok; Jung, Sung-Cherl; Park, Joo Min; Yoo, Eun-Sook; Kim, Seong-Ho; Ahn Jo, Sangmee; Suk, Kyoungho

    2015-01-01

    Excessive microglial activation and subsequent neuroinflammation lead to synaptic loss and dysfunction as well as neuronal cell death, which are involved in the pathogenesis and progression of several neurodegenerative diseases. Thus, the regulation of microglial activation has been evaluated as effective therapeutic strategies. Although dieckol (DEK), one of the phlorotannins isolated from marine brown alga Ecklonia cava, has been previously reported to inhibit microglial activation, the molecular mechanism is still unclear. Therefore, we investigated here molecular mechanism of DEK via extracellular signal-regulated kinase (ERK), Akt and nicotinamide adenine dinuclelotide phosphate (NADPH) oxidase-mediated pathways. In addition, the neuroprotective mechanism of DEK was investigated in microglia-mediated neurotoxicity models such as neuron-microglia co-culture and microglial conditioned media system. Our results demonstrated that treatment of anti-oxidant DEK potently suppressed phosphorylation of ERK in lipopolysaccharide (LPS, 1 µg/ml)-stimulated BV-2 microglia. In addition, DEK markedly attenuated Akt phosphorylation and increased expression of gp91phox, which is the catalytic component of NADPH oxidase complex responsible for microglial reactive oxygen species (ROS) generation. Finally, DEK significantly attenuated neuronal cell death that is induced by treatment of microglial conditioned media containing neurotoxic secretary molecules. These neuroprotective effects of DEK were also confirmed in a neuron-microglia co-culture system using enhanced green fluorescent protein (EGFP)-transfected B35 neuroblastoma cell line. Taken together, these results suggest that DEK suppresses excessive microglial activation and microglia-mediated neuronal cell death via downregulation of ERK, Akt and NADPH oxidase-mediated pathways. PMID:25954126

  5. Cell Cycle-Dependent Mechanisms Underlie Vincristine-Induced Death of Primary Acute Lymphoblastic Leukemia Cells.

    PubMed

    Kothari, Anisha; Hittelman, Walter N; Chambers, Timothy C

    2016-06-15

    Microtubule-targeting agents (MTA), such as the taxanes and vinca alkaloids, are used to treat a variety of cancers due to their ability to perturb microtubule dynamics. In cell culture, MTAs exert their anticancer effects primarily by causing mitotic arrest and cell death. However, accumulating indirect evidence suggests that MTAs may exert their cytotoxicity in human tumors by interfering with interphase microtubules. In this study, we sought to develop and characterize an experimental system in which to test the hypothesis that MTAs induce cell death during interphase. Primary adult acute lymphoblastic leukemia (ALL) cells treated with vincristine only weakly exhibited colocalization between mitotic and apoptotic markers and major characteristics of mitotic death, such as an increase in cells with 4N DNA content before the appearance of cells with <2N DNA content, suggesting a mixed response. Therefore, we separated ALL cells into distinct phases of the cell cycle by centrifugal elutriation, labeled cells with 5-ethynyl-2'-deoxyuridine (EdU), and then treated each population with vincristine. Cells isolated during G1 underwent cell death without evidence of EdU uptake, indicating that the cytotoxic effects of vincristine took place during G1 Conversely, cells isolated during S or G2-M phases underwent death following mitotic arrest. Thus, vincristine induces distinct death programs in primary ALL cells depending on cell-cycle phase, and cells in G1 are particularly susceptible to perturbation of interphase microtubules. Primary ALL cells may therefore provide a powerful model system in which to study the multimodal mechanisms underlying MTA-induced cell death. Cancer Res; 76(12); 3553-61. ©2016 AACR. PMID:27197148

  6. A Stem Cell Model of the Motor Circuit Uncouples Motor Neuron Death from Hyperexcitability Induced by SMN Deficiency.

    PubMed

    Simon, Christian M; Janas, Anna M; Lotti, Francesco; Tapia, Juan Carlos; Pellizzoni, Livio; Mentis, George Z

    2016-08-01

    In spinal muscular atrophy, a neurodegenerative disease caused by ubiquitous deficiency in the survival motor neuron (SMN) protein, sensory-motor synaptic dysfunction and increased excitability precede motor neuron (MN) loss. Whether central synaptic dysfunction and MN hyperexcitability are cell-autonomous events or they contribute to MN death is unknown. We addressed these issues using a stem-cell-based model of the motor circuit consisting of MNs and both excitatory and inhibitory interneurons (INs) in which SMN protein levels are selectively depleted. We show that SMN deficiency induces selective MN death through cell-autonomous mechanisms, while hyperexcitability is a non-cell-autonomous response of MNs to defects in pre-motor INs, leading to loss of glutamatergic synapses and reduced excitation. Findings from our in vitro model suggest that dysfunction and loss of MNs result from differential effects of SMN deficiency in distinct neurons of the motor circuit and that hyperexcitability does not trigger MN death. PMID:27452470

  7. 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

  8. Microglial AGE-albumin is critical for neuronal death in Parkinson’s disease: a possible implication for theranostics

    PubMed Central

    Bayarsaikhan, Enkhjargal; Bayarsaikhan, Delger; Lee, Jaesuk; Son, Myeongjoo; Oh, Seyeon; Moon, Jeongsik; Park, Hye-Jeong; Roshini, Arivazhagan; Kim, Seung U; Song, Byoung-Joon; Jo, Seung-Mook; Byun, Kyunghee; Lee, Bonghee

    2015-01-01

    Advanced glycation end products (AGEs) are known to play an important role in the pathogenesis of neurodegenerative diseases, including Parkinson’s disease (PD), by inducing protein aggregation and cross-link, formation of Lewy body, and neuronal death. In this study, we observed that AGE-albumin, the most abundant AGE product in the human PD brain, is synthesized in activated microglial cells and accumulates in the extracellular space. AGE-albumin synthesis in human-activated microglial cells is distinctly inhibited by ascorbic acid and cytochalasin treatment. Accumulated AGE-albumin upregulates the receptor to AGE, leading to apoptosis of human primary dopamine (DA) neurons. In animal experiments, we observed reduced DA neuronal cell death by treatment with soluble receptor to AGE. Our study provides evidence that activated microglial cells are one of the main contributors in AGE-albumin accumulation, deleterious to DA neurons in human and animal PD brains. Finally, activated microglial AGE-albumin could be used as a diagnostic and therapeutic biomarker with high sensitivity for neurodegenerative disorders, including PD. PMID:27601894

  9. Stress-induced nuclear translocation of CDK5 suppresses neuronal death by downregulating ERK activation via VRK3 phosphorylation.

    PubMed

    Song, Haengjin; Kim, Wanil; Choi, Jung-Hyun; Kim, Sung-Hoon; Lee, Dohyun; Park, Choon-Ho; Kim, Sangjune; Kim, Do-Yeon; Kim, Kyong-Tai

    2016-01-01

    Although extracellular signal-related kinase 1/2 (ERK 1/2) activity is generally associated with cell survival, prolonged ERK activation induced by oxidative stress also mediates neuronal cell death. Here we report that oxidative stress-induced cyclin-dependent kinase 5 (CDK5) activation stimulates neuroprotective signaling via phosphorylation of vaccinia-related kinase 3 (VRK3) at Ser 108. The binding of vaccinia H1-related (VHR) phosphatase to phosphorylated VRK3 increased its affinity for phospho-ERK and subsequently downregulated ERK activation. Overexpression of VRK3 protected human neuroblastoma SH-SY5Y cells against hydrogen peroxide (H2O2)-induced apoptosis. However the CDK5 was unable to phosphorylate mutant VRK3, and thus the mutant forms of VRK3 could not attenuate apoptotic process. Suppression of CDK5 activity results in increase of ERK activation and elevation of proapoptotic protein Bak expression in mouse cortical neurons. Results from VRK3-deficient neurons were further confirmed the role of VRK3 phosphorylation in H2O2-evoked ERK regulation. Importantly, we showed an association between phospho-VRK3 levels and the progression of human Alzheimer's disease (AD) and Parkinson's disease (PD). Together our work reveals endogenous protective mechanism against oxidative stress-induced neuronal cell death and suggest VRK3 as a potential therapeutic target in neurodegenerative diseases. PMID:27346674

  10. Inhibition of HIF-prolyl-4-hydroxylases prevents mitochondrial impairment and cell death in a model of neuronal oxytosis.

    PubMed

    Neitemeier, S; Dolga, A M; Honrath, B; Karuppagounder, S S; Alim, I; Ratan, R R; Culmsee, C

    2016-01-01

    Mitochondrial impairment induced by oxidative stress is a main characteristic of intrinsic cell death pathways in neurons underlying the pathology of neurodegenerative diseases. Therefore, protection of mitochondrial integrity and function is emerging as a promising strategy to prevent neuronal damage. Here, we show that pharmacological inhibition of hypoxia-inducible factor prolyl-4-hydroxylases (HIF-PHDs) by adaptaquin inhibits lipid peroxidation and fully maintains mitochondrial function as indicated by restored mitochondrial membrane potential and ATP production, reduced formation of mitochondrial reactive oxygen species (ROS) and preserved mitochondrial respiration, thereby protecting neuronal HT-22 cells in a model of glutamate-induced oxytosis. Selective reduction of PHD1 protein using CRISPR/Cas9 technology also reduced both lipid peroxidation and mitochondrial impairment, and attenuated glutamate toxicity in the HT-22 cells. Regulation of activating transcription factor 4 (ATF4) expression levels and related target genes may mediate these beneficial effects. Overall, these results expose HIF-PHDs as promising targets to protect mitochondria and, thereby, neurons from oxidative cell death. PMID:27148687

  11. Inhibition of HIF-prolyl-4-hydroxylases prevents mitochondrial impairment and cell death in a model of neuronal oxytosis

    PubMed Central

    Neitemeier, S; Dolga, A M; Honrath, B; Karuppagounder, S S; Alim, I; Ratan, R R; Culmsee, C

    2016-01-01

    Mitochondrial impairment induced by oxidative stress is a main characteristic of intrinsic cell death pathways in neurons underlying the pathology of neurodegenerative diseases. Therefore, protection of mitochondrial integrity and function is emerging as a promising strategy to prevent neuronal damage. Here, we show that pharmacological inhibition of hypoxia-inducible factor prolyl-4-hydroxylases (HIF-PHDs) by adaptaquin inhibits lipid peroxidation and fully maintains mitochondrial function as indicated by restored mitochondrial membrane potential and ATP production, reduced formation of mitochondrial reactive oxygen species (ROS) and preserved mitochondrial respiration, thereby protecting neuronal HT-22 cells in a model of glutamate-induced oxytosis. Selective reduction of PHD1 protein using CRISPR/Cas9 technology also reduced both lipid peroxidation and mitochondrial impairment, and attenuated glutamate toxicity in the HT-22 cells. Regulation of activating transcription factor 4 (ATF4) expression levels and related target genes may mediate these beneficial effects. Overall, these results expose HIF-PHDs as promising targets to protect mitochondria and, thereby, neurons from oxidative cell death. PMID:27148687

  12. Stress-induced nuclear translocation of CDK5 suppresses neuronal death by downregulating ERK activation via VRK3 phosphorylation

    PubMed Central

    Song, Haengjin; Kim, Wanil; Choi, Jung-Hyun; Kim, Sung-Hoon; Lee, Dohyun; Park, Choon-Ho; Kim, Sangjune; Kim, Do-Yeon; Kim, Kyong-Tai

    2016-01-01

    Although extracellular signal-related kinase 1/2 (ERK 1/2) activity is generally associated with cell survival, prolonged ERK activation induced by oxidative stress also mediates neuronal cell death. Here we report that oxidative stress-induced cyclin-dependent kinase 5 (CDK5) activation stimulates neuroprotective signaling via phosphorylation of vaccinia-related kinase 3 (VRK3) at Ser 108. The binding of vaccinia H1-related (VHR) phosphatase to phosphorylated VRK3 increased its affinity for phospho-ERK and subsequently downregulated ERK activation. Overexpression of VRK3 protected human neuroblastoma SH-SY5Y cells against hydrogen peroxide (H2O2)-induced apoptosis. However the CDK5 was unable to phosphorylate mutant VRK3, and thus the mutant forms of VRK3 could not attenuate apoptotic process. Suppression of CDK5 activity results in increase of ERK activation and elevation of proapoptotic protein Bak expression in mouse cortical neurons. Results from VRK3-deficient neurons were further confirmed the role of VRK3 phosphorylation in H2O2-evoked ERK regulation. Importantly, we showed an association between phospho-VRK3 levels and the progression of human Alzheimer’s disease (AD) and Parkinson’s disease (PD). Together our work reveals endogenous protective mechanism against oxidative stress-induced neuronal cell death and suggest VRK3 as a potential therapeutic target in neurodegenerative diseases. PMID:27346674

  13. Alpha-Synuclein Oligomers Interact with Metal Ions to Induce Oxidative Stress and Neuronal Death in Parkinson's Disease

    PubMed Central

    Deas, Emma; Cremades, Nunilo; Angelova, Plamena R.; Ludtmann, Marthe H.R.; Yao, Zhi; Chen, Serene; Horrocks, Mathew H.; Banushi, Blerida; Little, Daniel; Devine, Michael J.; Gissen, Paul; Klenerman, David; Dobson, Christopher M.; Wood, Nicholas W.

    2016-01-01

    Abstract Aims: Protein aggregation and oxidative stress are both key pathogenic processes in Parkinson's disease, although the mechanism by which misfolded proteins induce oxidative stress and neuronal death remains unknown. In this study, we describe how aggregation of alpha-synuclein (α-S) from its monomeric form to its soluble oligomeric state results in aberrant free radical production and neuronal toxicity. Results: We first demonstrate excessive free radical production in a human induced pluripotent stem-derived α-S triplication model at basal levels and on application of picomolar doses of β-sheet-rich α-S oligomers. We probed the effects of different structural species of α-S in wild-type rat neuronal cultures and show that both oligomeric and fibrillar forms of α-S are capable of generating free radical production, but that only the oligomeric form results in reduction of endogenous glutathione and subsequent neuronal toxicity. We dissected the mechanism of oligomer-induced free radical production and found that it was interestingly independent of several known cellular enzymatic sources. Innovation: The oligomer-induced reactive oxygen species (ROS) production was entirely dependent on the presence of free metal ions as addition of metal chelators was able to block oligomer-induced ROS production and prevent oligomer-induced neuronal death. Conclusion: Our findings further support the causative role of soluble amyloid oligomers in triggering neurodegeneration and shed light into the mechanisms by which these species cause neuronal damage, which, we show here, can be amenable to modulation through the use of metal chelation. Antioxid. Redox Signal. 24, 376–391. PMID:26564470

  14. Brain-specific knockdown of miR-29 results in neuronal cell death and ataxia in mice

    PubMed Central

    Roshan, Reema; Shridhar, Shruti; Sarangdhar, Mayuresh A.; Banik, Arpita; Chawla, Mrinal; Garg, Manali; Singh, Vijay PAL; Pillai, Beena

    2014-01-01

    Several microRNAs have been implicated in neurogenesis, neuronal differentiation, neurodevelopment, and memory. Development of miRNA-based therapeutics, however, needs tools for effective miRNA modulation, tissue-specific delivery, and in vivo evidence of functional effects following the knockdown of miRNA. Expression of miR-29a is reduced in patients and animal models of several neurodegenerative disorders, including Alzheimer's disease, Huntington's disease, and spinocerebellar ataxias. The temporal expression pattern of miR-29b during development also correlates with its protective role in neuronal survival. Here, we report the cellular and behavioral effect of in vivo, brain-specific knockdown of miR-29. We delivered specific anti-miRNAs to the mouse brain using a neurotropic peptide, thus overcoming the blood-brain-barrier and restricting the effect of knockdown to the neuronal cells. Large regions of the hippocampus and cerebellum showed massive cell death, reiterating the role of miR-29 in neuronal survival. The mice showed characteristic features of ataxia, including reduced step length. However, the apoptotic targets of miR-29, such as Puma, Bim, Bak, or Bace1, failed to show expected levels of up-regulation in mice, following knockdown of miR-29. In contrast, another miR-29 target, voltage-dependent anion channel1 (VDAC1), was found to be induced several fold in the hippocampus, cerebellum, and cortex of mice following miRNA knockdown. Partial restoration of apoptosis was achieved by down-regulation of VDAC1 in miR-29 knockdown cells. Our study suggests that regulation of VDAC1 expression by miR-29 is an important determinant of neuronal cell survival in the brain. Loss of miR-29 results in dysregulation of VDAC1, neuronal cell death, and an ataxic phenotype. PMID:24958907

  15. 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

  16. 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

  17. 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

  18. 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

  19. A Case of Acute Motor Axonal Neuropathy Mimicking Brain Death and Review of the Literature

    PubMed Central

    Ravikumar, Sandhya; Poysophon, Poysophon; Poblete, Roy; Kim-Tenser, May

    2016-01-01

    We describe a case report of fulminant Guillain–Barré syndrome (GBS) mimicking brain death. A previously healthy 60-year-old male was admitted to the neurointensive care unit after developing rapidly progressive weakness and respiratory failure. On presentation, the patient was found to have absent brainstem and spinal cord reflexes resembling that of brain death. Acute motor axonal neuropathy, a subtype of GBS, was diagnosed by cerebrospinal fluid and nerve conduction velocity testing. An electroencephalogram showed that the patient had normal, appropriately reactive brain function. Transcranial Doppler (TCD) ultrasound showed appropriate blood flow to the brain. GBS rarely presents with weakness so severe as to mimic brain death. This article provides a review of similar literature. This case demonstrates the importance of performing a proper brain death examination, which includes evaluation for irreversible cerebral injury, exclusion of any confounding conditions, and performance of tests such as electroencephalography and TCDs when uncertainty exists about the reliability of the clinical exam. PMID:27199887

  20. Attenuation of cisplatin-induced acute renal failure is associated with less apoptotic cell death.

    PubMed

    Zhou, H; Miyaji, T; Kato, A; Fujigaki, Y; Sano, K; Hishida, A

    1999-12-01

    To clarify the pathophysiologic role of apoptosis in acute renal failure (ARF), we examined whether the attenuation of cisplatin-induced ARF is associated with the change in the degree of apoptotic cell death. The administration of cisplatin (CDDP) (6 mg/kg body weight) in rats induced ARF at day 5, as manifested by a significant increase in serum creatinine (Scr) and tubular damage. CDDP-induced apoptotic cell death was confirmed by electron microscopic examination, agarose gel electrophoresis, and increased cells positive for TaT-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) in the outer medulla of the kidney. Treatment with dimethylthiourea (DMTU)--a scavenger of hydroxyl radicals--or glycine abrogated CDDP-induced increases in Scr, the tubular damage score, and the number of TUNEL-positive cells. Pretreatment with uranyl acetate (UA) induced a significant expression of Bcl-2 in the kidney and ameliorated CDDP-induced increases in Scr, the tubular damage score, and TUNEL-positive cells in the outer stripe of the outer medulla. Our findings indicate (1) that the attenuation of CDDP-induced ARF was associated with less apoptotic cell death and (2) that the induction of the anti-apoptotic protein Bcl-2 attenuated apoptosis and tubular damage. Our results suggest that apoptotic cell death may play an important role in the development of cisplatin-induced ARF. PMID:10595794

  1. Association of Acute Interstitial Nephritis With Programmed Cell Death 1 Inhibitor Therapy in Lung Cancer Patients.

    PubMed

    Shirali, Anushree C; Perazella, Mark A; Gettinger, Scott

    2016-08-01

    Immune checkpoint inhibitors that target the programmed death 1 (PD-1) signaling pathway have recently been approved for use in advanced pretreated non-small cell lung cancer and melanoma. Clinical trial data suggest that these drugs may have adverse effects on the kidney, but these effects have not been well described. We present 6 cases of acute kidney injury in patients with lung cancer who received anti-PD-1 antibodies, with each case displaying evidence of acute interstitial nephritis (AIN) on kidney biopsy. All patients were also treated with other drugs (proton pump inhibitors and nonsteroidal anti-inflammatory drugs) linked to AIN, but in most cases, use of these drugs long preceded PD-1 inhibitor therapy. The association of AIN with these drugs in our patients raises the possibility that PD-1 inhibitor therapy may release suppression of T-cell immunity that normally permits renal tolerance of drugs known to be associated with AIN. PMID:27113507

  2. Differential roles of GluN2A- and GluN2B-containing NMDA receptors in neuronal survival and death

    PubMed Central

    Lujan, Brendan; Liu, Xiaoxuan; Wan, Qi

    2012-01-01

    Glutamate-induced neurotoxicity is the primary molecular mechanism that induces neuronal death in a variety of pathologies in central nervous system (CNS). Toxicity signals are relayed from extracellular space to the cytoplasm by N-methyl-D-aspartate receptors (NMDARs) and regulate a variety of survival and death signaling. Differential subunit combinations of NMDARs confer neuroprotection or trigger neuronal death pathways depending on the subunit arrangements of NMDARs and its localization on the cell membrane. It is well-known that GluN2B-contaning NMDARs (GluN2BRs) preferentially link to signaling cascades involved in CNS injury promoting neuronal death and neurodegeneration. Conversely, less well-known mechanisms of neuronal survival signaling are associated with GluN2A-comtaining NMDARs (GluN2AR)-dependent signal pathways. This review will discuss the most recent signaling cascades associated with GluN2ARs and GluN2BRs. PMID:23320134

  3. 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

  4. Treatment-related deaths in second complete remission in childhood acute myeloid leukaemia.

    PubMed

    Molgaard-Hansen, Lene; Möttönen, Merja; Glosli, Heidi; Jónmundsson, Guðmundur K; Abrahamsson, Jonas; Hasle, Henrik

    2011-03-01

    The frequency and causes of treatment-related deaths (TRD) in second complete remission (CR2) in acute myeloid leukaemia (AML) were investigated in a historical, prospective cohort study of 429 children included in the Nordic Society of Paediatric Haematology and Oncology (NOPHO)-AML-88 and -93 trials. Relapse occurred in 158 children (39%). Seventeen (18%) of the 96 patients entering CR2 suffered TRD. The main causes were infection (59%) and complications from graft-versus-host disease (22%). Fourteen (82%) of 17 TRDs occurred in children undergoing haematopoietic stem cell transplantations (HSCT). Optimal supportive care after HSCT is essential, and studies on risk factors for TRD are needed. PMID:21241281

  5. Prothrombin kringle-2 induces death of mesencephalic dopaminergic neurons in vivo and in vitro via microglial activation.

    PubMed

    Kim, Sang Ryong; Chung, Eun Sook; Bok, Eugene; Baik, Hyung Hwan; Chung, Young Cheul; Won, So Yoon; Joe, Eunhye; Kim, Tae Hyong; Kim, Soung Soo; Jin, Min Young; Choi, Sang Ho; Jin, Byung Kwan

    2010-05-15

    We have shown that prothrombin kringle-2 (pKr-2), a domain of human prothrombin distinct from thrombin could activate cultured rat brain microglia in vitro. However, little is known whether pKr-2-induced microglial activation could cause neurotoxicity on dopaminergic (DA) neurons in vivo. To address this question, pKr-2 was injected into the rat substantia nigra (SN). Tyrosine hydroxylase (TH) immunohistochemistry experiments demonstrate significant loss of DA neurons seven days after injection of pKr-2. In parallel, pKr-2-activated microglia were detected in the SN with OX-42 and OX-6 immunohistochemistry. Reverse transcription PCR and double-label immunohistochemistry revealed that activated microglia in vivo exhibit early and transient expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and several proinflammatory cytokines. The pKr-2-induced loss of SN DA neurons was partially inhibited by the NOS inhibitor N(G)-nitro-L-arginine methyl ester hydrochloride, and the COX-2 inhibitor DuP-697. Extracellular signal-regulated kinase 1/2, c-Jun N-terminal kinase and p38 mitogen-activated protein kinase were activated in the SN as early as 1 hr after pKr-2 injection, and localized within microglia. Inhibition of these kinases led to attenuation of mRNA expression of iNOS, COX-2 and several proinflammatory cytokines, and rescue of DA neurons in the SN. Intriguingly, following treatment with pKr-2 in vitro, neurotoxicity was detected exclusively in co-cultures of mesencephalic neurons and microglia, but not microglia-free neuron-enriched mesencephalic cultures, indicating that microglia are required for pKr-2 neurotoxicity. Our results strongly suggest that microglia activated by endogenous compound(s), such as pKr-2, are implicated in the DA neuronal cell death in the SN. PMID:20025058

  6. Peroxynitrite is Involved in the Apoptotic Death of Cultured Cerebellar Granule Neurons Induced by Staurosporine, but not by Potassium Deprivation.

    PubMed

    Olguín-Albuerne, Mauricio; Ramos-Pittol, José Miguel; Coyoy, Angélica; Martínez-Briseño, Carlos Patricio; Domínguez, Guadalupe; Morán, Julio

    2016-02-01

    Nitric oxide (NO) regulates numerous physiological process and is the main source of reactive nitrogen species (RNS). NO promotes cell survival, but it also induces apoptotic death having been involved in the pathogenesis of several neurodegenerative diseases. NO and superoxide anion react to form peroxynitrite, which accounts for most of the deleterious effects of NO. The mechanisms by which these molecules regulate the apoptotic process are not well understood. In this study, we evaluated the role of NO and peroxynitrite in the apoptotic death of cultured cerebellar granule neurons (CGN), which are known to experience apoptosis by staurosporine (St) or potassium deprivation (K5). We found that CGN treated with the peroxynitrite catalyst, FeTTPs were completely rescued from St-induced death, but not from K5-induced death. On the other hand, the inhibition of the inducible nitric oxide synthase partially protected cell viability in CGN treated with K5, but not with St, while the inhibitor L-NAME further reduced the cell viability in St, but it did not affect K5. Finally, an inhibitor of the soluble guanylate cyclase (sGC) diminished the cell viability in K5, but not in St. Altogether, these results shows that NO promotes cell survival in K5 through sGC-cGMP and promotes cell death by other mechanisms, while in St NO promotes cell survival independently of cGMP and peroxynitrite results critical for St-induced death. Our results suggest that RNS are differentially handled by CGN during cell death depending on the death-inducing conditions. PMID:26700430

  7. NRA-2, a Nicalin Homolog, Regulates Neuronal Death by Controlling Surface Localization of Toxic Caenorhabditis elegans DEG/ENaC Channels*

    PubMed Central

    Kamat, Shaunak; Yeola, Shrutika; Zhang, Wenying; Bianchi, Laura; Driscoll, Monica

    2014-01-01

    Hyperactivated DEG/ENaCs induce neuronal death through excessive cation influx and disruption of intracellular calcium homeostasis. Caenorhabditis elegans DEG/ENaC MEC-4 is hyperactivated by the (d) mutation and induces death of touch neurons. The analogous substitution in MEC-10 (MEC-10(d)) co-expressed in the same neurons is only mildly neurotoxic. We exploited the lower toxicity of MEC-10(d) to identify RNAi knockdowns that enhance neuronal death. We report here that knock-out of the C. elegans nicalin homolog NRA-2 enhances MEC-10(d)-induced neuronal death. Cell biological assays in C. elegans neurons show that NRA-2 controls the distribution of MEC-10(d) between the endoplasmic reticulum and the cell surface. Electrophysiological experiments in Xenopus oocytes support this notion and suggest that control of channel distribution by NRA-2 is dependent on the subunit composition. We propose that nicalin/NRA-2 functions in a quality control mechanism to retain mutant channels in the endoplasmic reticulum, influencing the extent of neuronal death. Mammalian nicalin may have a similar role in DEG/ENaC biology, therefore influencing pathological conditions like ischemia. PMID:24567339

  8. Involvement of cyclin D1/CDK4 and pRb mediated by PI3K/AKT pathway activation in Pb{sup 2+}-induced neuronal death in cultured hippocampal neurons

    SciTech Connect

    Li Chenchen Xing Tairan Tang Mingliang Yong Wu Yan Dan Deng Hongmin Wang Huili Wang Ming Chen Jutao Ruan Diyun

    2008-06-15

    Lead (Pb) is widely recognized as a neurotoxicant. One of the suggested mechanisms of lead neurotoxicity is apoptotic cell death. And the mechanism by which Pb{sup 2+} causes neuronal death is not well understood. The present study sought to examine the obligate nature of cyclin D1/cyclin-dependent kinase 4 (CDK4), phosphorylation of its substrate retinoblastoma protein (pRb) and its select upstream signal phosphoinositide 3-kinase (PI3K)/AKT pathway in the death of primary cultured rat hippocampal neurons evoked by Pb{sup 2+}. Our data showed that lead treatment of primary hippocampal cultures results in dose-dependent cell death. Inhibition of CDK4 prevented Pb{sup 2+}-induced neuronal death significantly but was incomplete. In addition, we demonstrated that the levels of cyclin D1 and pRb/p107 were increased during Pb{sup 2+} treatment. These elevated expression persisted up to 48 h, returning to control levels after 72 h. We also presented pharmacological and morphological evidences that cyclin D1/CDK4 and pRb/p107 were required for such kind of neuronal death. Addition of the PI3K inhibitor LY294002 (30 {mu}M) or wortmannin (100 nM) significantly rescued the cultured hippocampal neurons from death caused by Pb{sup 2+}. And that Pb{sup 2+}-elicited phospho-AKT (Ser473) participated in the induction of cyclin D1 and partial pRb/p107 expression. These results provide evidences that cell cycle elements play a required role in the death of neurons evoked by Pb{sup 2+} and suggest that certain signaling elements upstream of cyclin D1/CDK4 are modified and/or required for this form of neuronal death.

  9. Protective substances against zinc-induced neuronal death after ischemia: carnosine as a target for drug of vascular type of dementia.

    PubMed

    Kawahara, Masahiro; Konoha, Keiko; Nagata, Tetsuya; Sadakane, Yutaka

    2007-06-01

    Recent studies have indicated the significance of zinc in neurodegeneration after transient global ischemia. After ischemia, excess glutamate and zinc, which are released in the synaptic clefts, cause the apoptotic death of the target neurons, and finally lead the pathogenesis of vascular type of dementia. Considering the removal of zinc using zinc-sensitive chelators was effective in the prevention of neuronal death after transient global ischemia, it is highly possible that substances which protect against zinc-induced neuronal death will become a candidate for drugs of vascular type of dementia. Based on this 'zinc hypothesis', we have searched for such substances among various agricultural products including fruits, vegetables, and fishes using our developed in vitro screening system. Among tested, we found that carnosine (beta-alanyl histidine) protected against zinc-induced death of cultured neurons, and have applied for the patent as a drug of ischemia-induced neuronal death and the treatment/prevention for vascular type of dementia (application No. 2006-145857) in Japan. Here, we review the perspective of protective substances of zinc-induced neuronal death as a drug of vascular type of dementia based on our studies and other numerous studies. PMID:18221226

  10. Naphthazarin protects against glutamate-induced neuronal death via activation of the Nrf2/ARE pathway

    SciTech Connect

    Son, Tae Gen; Kawamoto, Elisa M.; Yu, Qian-Sheng; Greig, Nigel H.; Mattson, Mark P.; Camandola, Simonetta

    2013-04-19

    Highlights: •Naphthazarin activates the Nrf2/ARE pathway. •Naphthazarin induces Nrf2-driven genes in neurons and astrocytes. •Naphthazarin protects neurons against excitotoxicity. -- Abstract: Nuclear factor E2-related factor 2 (Nrf2)/antioxidant response element (ARE) pathway is an important cellular stress response pathway involved in neuroprotection. We previously screened several natural phytochemicals and identified plumbagin as a novel activator of the Nrf2/ARE pathway that can protect neurons against ischemic injury. Here we extended our studies to natural and synthetic derivatives of plumbagin. We found that 5,8-dimethoxy-1,4-naphthoquinone (naphthazarin) is a potent activator of the Nrf2/ARE pathway, up-regulates the expression of Nrf2-driven genes in primary neuronal and glial cultures, and protects neurons against glutamate-induced excitotoxicity.

  11. Transduced PEP-1-PON1 proteins regulate microglial activation and dopaminergic neuronal death in a Parkinson's disease model.

    PubMed

    Kim, Mi Jin; Park, Meeyoung; Kim, Dae Won; Shin, Min Jea; Son, Ora; Jo, Hyo Sang; Yeo, Hyeon Ji; Cho, Su Bin; Park, Jung Hwan; Lee, Chi Hern; Kim, Duk-Soo; Kwon, Oh-Shin; Kim, Joon; Han, Kyu Hyung; Park, Jinseu; Eum, Won Sik; Choi, Soo Young

    2015-09-01

    Parkinson's disease (PD) is an oxidative stress-mediated neurodegenerative disorder caused by selective dopaminergic neuronal death in the midbrain substantia nigra. Paraoxonase 1 (PON1) is a potent inhibitor of low-density lipoprotein (LDL) and high-density lipoprotein (HDL) against oxidation by destroying biologically active phospholipids with potential protective effects against oxidative stress-induced inflammatory disorders. In a previous study, we constructed protein transduction domain (PTD) fusion PEP-1-PON1 protein to transduce PON1 into cells and tissue. In this study, we examined the role of transduced PEP-1-PON1 protein in repressing oxidative stress-mediated inflammatory response in microglial BV2 cells after exposure to lipopolysaccharide (LPS). Moreover, we identified the functions of transduced PEP-1-PON1 proteins which include, mitigating mitochondrial damage, decreasing reactive oxidative species (ROS) production, matrix metalloproteinase-9 (MMP-9) expression and protecting against 1-methyl-4-phenylpyridinium (MPP(+))-induced neurotoxicity in SH-SY5Y cells. Furthermore, transduced PEP-1-PON1 protein reduced MMP-9 expression and protected against dopaminergic neuronal cell death in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mice model. Taken together, these results suggest a promising therapeutic application of PEP-1-PON1 proteins against PD and other inflammation and oxidative stress-related neuronal diseases. PMID:26117230

  12. Role of the Mitochondrial Calcium Uniporter in Rat Hippocampal Neuronal Death After Pilocarpine-Induced Status Epilepticus.

    PubMed

    Wang, Cui; Xie, Nanchang; Wang, Yunlong; Li, Yulin; Ge, Xinjie; Wang, Menglu

    2015-08-01

    The mitochondrial calcium uniporter (MCU) is reportedly involved in oxidative stress, apoptosis, and many neurological diseases. However, the role of the MCU in epilepsy remains unknown. In this study, we found that the MCU inhibitor Ru360 significantly attenuated neuronal death and exerted an anti-apoptotic effect on rat hippocampal neurons after pilocarpine-induced status epilepticus (SE), while the MCU activator spermine increased seizure-induced neuronal death and apoptosis. In addition, Ru360 decreased the level of seizure-induced reactive oxygen species (ROS) in mitochondria isolated from rat hippocampi. Moreover, Ru360 restored the altered mitochondrial membrane potential and cytochrome c (CytC) release in epileptic hippocampi. However, spermine treatment exerted an opposite effect on seizure-induced ROS production and mitochondrial membrane potential alteration and CytC release compared with Ru360 treatment. Altogether, the findings of this study suggest that MCU inhibition exerts a neuroprotective effect on seizure-induced brain injury possibly through the mitochondria/ROS/CytC pathway. PMID:26148531

  13. Sudden cardiac death after acute ST elevation myocardial infarction: insight from a developing country

    PubMed Central

    Rao, Hygriv B; Sastry, B K S; Korabathina, Radhika; Raju, Krishnam P

    2012-01-01

    Background There is no data concerning sudden cardiac death (SCD) following acute ST elevation myocardial infarction (STEMI) in India. We assessed the incidence and factors influencing SCD following STEMI. Methods Patients with STEMI admitted in our hospital from 2006 to 2009 were prospectively entered into a database. In the period 2010–2011, patients or their kin were periodically contacted and administered a questionnaire to ascertain their survival, and mode of death if applicable. Results Study population comprised of 929 patients with STEMI (mean age 55±17 years) having a mean follow-up of 41±16 months. The total number of deaths was 159, of which 78 were SCD (mean age 62.2±10 years). The cumulative incidence of total deaths and SCD at 1 month, 1, 2, 3 years and at conclusion of the study was 10.1%, 13.2%, 14.6%, 15.8%, 17.3% and 4.9%, 6.5%, 8.0%, 8.9% and 9.7%, respectively. The temporal distribution of SCD was 53.9% at first month, 19.2% at 1 month to 1 year, 15.4% in 1–2 years, 7.6% in 2–3 years and 3.8% beyond 3 years. Comparison between SCD and survivor cohorts by multivariate analysis showed five variables were found to be associated with SCD (age p=0.0163, female gender p=0.0042, severe LV dysfunction p=0.0292, absence of both reperfusion and revascularisation p=0.0373 and lack of compliance with medications p <0.0001). Conclusions SCD following STEMI accounts for about half of the total deaths. It involves younger population and most of these occur within the first month. This data has relevance in prioritising healthcare strategies in India. PMID:27326036

  14. Spontaneous coronary artery dissection: a neglected cause of acute myocardial ischaemia and sudden death.

    PubMed Central

    Basso, C.; Morgagni, G. L.; Thiene, G.

    1996-01-01

    Spontaneous coronary artery dissection is a rare cause of acute myocardial ischaemia. Eight consecutive fatal cases which occurred in women aged 34-54 years (mean 43) are described. The dissection involved the left anterior descending coronary artery in four, the left main trunk in two, the right coronary artery in one, and both left anterior descending and circumflex arteries in one. The clinical presentation was sudden death in six cases, and acute myocardial infarction in two. Diagnosis was made at necropsy in every case but one, in which coronary dissection was diagnosed during life by selective coronary angiography. The only ascertained risk factor was hypertension in one patient; none of the women was in the puerperium, and Marfan syndrome was excluded in all. Histology showed a haematoma between the coronary tunica media and adventitia, that flattened and occluded the lumen; a coronary intimal tear was detected in only two cases. Unusual histological findings were cystic medial necrosis in one case, eosinophilic inflammatory infiltrates in four, and angiomatosis of the tunica adventitia in one. Patients dying of spontaneous coronary dissection are usually middle aged women, with no coronary atherosclerosis and apparently no risk factors. Spontaneous coronary artery dissection is unpredictable, and sudden death is the usual mode of clinical presentation. Prompt diagnosis and life saving treatment is far from being achieved. Images PMID:8665336

  15. 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

  16. Dysregulation of the ALS-associated gene TDP-43 leads to neuronal death and degeneration in mice.

    PubMed

    Igaz, Lionel M; Kwong, Linda K; Lee, Edward B; Chen-Plotkin, Alice; Swanson, Eric; Unger, Travis; Malunda, Joe; Xu, Yan; Winton, Matthew J; Trojanowski, John Q; Lee, Virginia M-Y

    2011-02-01

    Amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) are characterized by cytoplasmic protein aggregates in the brain and spinal cord that include TAR-DNA binding protein 43 (TDP-43). TDP-43 is normally localized in the nucleus with roles in the regulation of gene expression, and pathological cytoplasmic aggregates are associated with depletion of nuclear protein. Here, we generated transgenic mice expressing human TDP-43 with a defective nuclear localization signal in the forebrain (hTDP-43-ΔNLS), and compared them with mice expressing WT hTDP-43 (hTDP-43-WT) to determine the effects of mislocalized cytoplasmic TDP-43 on neuronal viability. Expression of either hTDP-43-ΔNLS or hTDP-43-WT led to neuron loss in selectively vulnerable forebrain regions, corticospinal tract degeneration, and motor spasticity recapitulating key aspects of FTLD and primary lateral sclerosis. Only rare cytoplasmic phosphorylated and ubiquitinated TDP-43 inclusions were seen in hTDP-43-ΔNLS mice, suggesting that cytoplasmic inclusions were not required to induce neuronal death. Instead, neurodegeneration in hTDP-43 and hTDP-43-ΔNLS-expressing neurons was accompanied by a dramatic downregulation of the endogenous mouse TDP-43. Moreover, mice expressing hTDP-43-ΔNLS exhibited profound changes in gene expression in cortical neurons. Our data suggest that perturbation of endogenous nuclear TDP-43 results in loss of normal TDP-43 function(s) and gene regulatory pathways, culminating in degeneration of selectively vulnerable affected neurons. PMID:21206091

  17. Thioredoxin-2 Modulates Neuronal Programmed Cell Death in the Embryonic Chick Spinal Cord in Basal and Target-Deprived Conditions

    PubMed Central

    Pirson, Marc; Debrulle, Stéphanie; Clippe, André; Clotman, Frédéric; Knoops, Bernard

    2015-01-01

    Thioredoxin-2 (Trx2) is a mitochondrial protein using a dithiol active site to reduce protein disulfides. In addition to the cytoprotective function of this enzyme, several studies have highlighted the implication of Trx2 in cellular signaling events. In particular, growing evidence points to such roles of redox enzymes in developmental processes taking place in the central nervous system. Here, we investigate the potential implication of Trx2 in embryonic development of chick spinal cord. To this end, we first studied the distribution of the enzyme in this tissue and report strong expression of Trx2 in chick embryo post-mitotic neurons at E4.5 and in motor neurons at E6.5. Using in ovo electroporation, we go on to highlight a cytoprotective effect of Trx2 on the programmed cell death (PCD) of neurons during spinal cord development and in a novel cultured spinal cord explant model. These findings suggest an implication of Trx2 in the modulation of developmental PCD of neurons during embryonic development of the spinal cord, possibly through redox regulation mechanisms. PMID:26540198

  18. 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

  19. Lapatinib induces autophagic cell death and differentiation in acute myeloblastic leukemia.

    PubMed

    Chen, Yu-Jen; Fang, Li-Wen; Su, Wen-Chi; Hsu, Wen-Yi; Yang, Kai-Chien; Huang, Huey-Lan

    2016-01-01

    Lapatinib is an oral-form dual tyrosine kinase inhibitor of epidermal growth factor receptor (EGFR or ErbB/Her) superfamily members with anticancer activity. In this study, we examined the effects and mechanism of action of lapatinib on several human leukemia cells lines, including acute myeloid leukemia (AML), chronic myeloid leukemia (CML), and acute lymphoblastic leukemia (ALL) cells. We found that lapatinib inhibited the growth of human AML U937, HL-60, NB4, CML KU812, MEG-01, and ALL Jurkat T cells. Among these leukemia cell lines, lapatinib induced apoptosis in HL-60, NB4, and Jurkat cells, but induced nonapoptotic cell death in U937, K562, and MEG-01 cells. Moreover, lapatinib treatment caused autophagic cell death as shown by positive acridine orange staining, the massive formation of vacuoles as seen by electronic microscopy, and the upregulation of LC3-II, ATG5, and ATG7 in AML U937 cells. Furthermore, autophagy inhibitor 3-methyladenine and knockdown of ATG5, ATG7, and Beclin-1 using short hairpin RNA (shRNA) partially rescued lapatinib-induced cell death. In addition, the induction of phagocytosis and ROS production as well as the upregulation of surface markers CD14 and CD68 was detected in lapatinib-treated U937 cells, suggesting the induction of macrophagic differentiation in AML U937 cells by lapatinib. We also noted the synergistic effects of the use of lapatinib and cytotoxic drugs in U937 leukemia cells. These results indicate that lapatinib may have potential for development as a novel antileukemia agent. PMID:27499639

  20. Lapatinib induces autophagic cell death and differentiation in acute myeloblastic leukemia

    PubMed Central

    Chen, Yu-Jen; Fang, Li-Wen; Su, Wen-Chi; Hsu, Wen-Yi; Yang, Kai-Chien; Huang, Huey-Lan

    2016-01-01

    Lapatinib is an oral-form dual tyrosine kinase inhibitor of epidermal growth factor receptor (EGFR or ErbB/Her) superfamily members with anticancer activity. In this study, we examined the effects and mechanism of action of lapatinib on several human leukemia cells lines, including acute myeloid leukemia (AML), chronic myeloid leukemia (CML), and acute lymphoblastic leukemia (ALL) cells. We found that lapatinib inhibited the growth of human AML U937, HL-60, NB4, CML KU812, MEG-01, and ALL Jurkat T cells. Among these leukemia cell lines, lapatinib induced apoptosis in HL-60, NB4, and Jurkat cells, but induced nonapoptotic cell death in U937, K562, and MEG-01 cells. Moreover, lapatinib treatment caused autophagic cell death as shown by positive acridine orange staining, the massive formation of vacuoles as seen by electronic microscopy, and the upregulation of LC3-II, ATG5, and ATG7 in AML U937 cells. Furthermore, autophagy inhibitor 3-methyladenine and knockdown of ATG5, ATG7, and Beclin-1 using short hairpin RNA (shRNA) partially rescued lapatinib-induced cell death. In addition, the induction of phagocytosis and ROS production as well as the upregulation of surface markers CD14 and CD68 was detected in lapatinib-treated U937 cells, suggesting the induction of macrophagic differentiation in AML U937 cells by lapatinib. We also noted the synergistic effects of the use of lapatinib and cytotoxic drugs in U937 leukemia cells. These results indicate that lapatinib may have potential for development as a novel antileukemia agent. PMID:27499639

  1. Dasatinib accelerates valproic acid-induced acute myeloid leukemia cell death by regulation of differentiation capacity.

    PubMed

    Heo, Sook-Kyoung; Noh, Eui-Kyu; Yoon, Dong-Joon; Jo, Jae-Cheol; Park, Jae-Hoo; Kim, Hawk

    2014-01-01

    Dasatinib is a compound developed for chronic myeloid leukemia as a multi-targeted kinase inhibitor against wild-type BCR-ABL and SRC family kinases. Valproic acid (VPA) is an anti-epileptic drug that also acts as a class I histone deacetylase inhibitor. The aim of this research was to determine the anti-leukemic effects of dasatinib and VPA in combination and to identify their mechanism of action in acute myeloid leukemia (AML) cells. Dasatinib was found to exert potent synergistic inhibitory effects on VPA-treated AML cells in association with G1 phase cell cycle arrest and apoptosis induction involving the cleavage of poly (ADP-ribose) polymerase and caspase-3, -7 and -9. Dasatinib/VPA-induced cell death thus occurred via caspase-dependent apoptosis. Moreover, MEK/ERK and p38 MAPK inhibitors efficiently inhibited dasatinib/VPA-induced apoptosis. The combined effect of dasatinib and VPA on the differentiation capacity of AML cells was more powerful than the effect of each drug alone, being sufficiently strong to promote AML cell death through G1 cell cycle arrest and caspase-dependent apoptosis. MEK/ERK and p38 MAPK were found to control dasatinib/VPA-induced apoptosis as upstream regulators, and co-treatment with dasatinib and VPA to contribute to AML cell death through the regulation of differentiation capacity. Taken together, these results indicate that combined dasatinib and VPA treatment has a potential role in anti-leukemic therapy. PMID:24918603

  2. An orchestrated gene expression component of neuronal programmed cell death revealed by cDNA array analysis

    PubMed Central

    Chiang, Lillian W.; Grenier, Jill M.; Ettwiller, Laurence; Jenkins, Lorayne P.; Ficenec, Dave; Martin, John; Jin, Fenyu; DiStefano, Peter S.; Wood, Andrew

    2001-01-01

    Programmed cell death (PCD) during neuronal development and disease has been shown to require de novo RNA synthesis. However, the time course and regulation of target genes is poorly understood. By using a brain-biased array of over 7,500 cDNAs, we profiled this gene expression component of PCD in cerebellar granule neurons challenged separately by potassium withdrawal, combined potassium and serum withdrawal, and kainic acid administration. We found that hundreds of genes were significantly regulated in discreet waves including known genes whose protein products are involved in PCD. A restricted set of genes was regulated by all models, providing evidence that signals inducing PCD can regulate large assemblages of genes (of which a restricted subset may be shared in multiple pathways). PMID:11226323

  3. Protection of dichlorvos induced oxidative stress and nigrostriatal neuronal death by chronic Coenzyme Q{sub 10} pretreatment

    SciTech Connect

    Binukumar, BK; Gupta, Nidhi; Bal, Amanjit; Gill, Kiran Dip

    2011-10-01

    Numerous epidemiological studies have shown an association between pesticide exposure and increased risk of developing Parkinson's diseases. Oxidative stress generated as a result of mitochondrial dysfunction has been implicated as an important factor in the etiology of Parkinson's disease. Previously, we reported that chronic dichlorvos exposure causes mitochondrial impairments and nigrostriatal neuronal death in rats. The present study was designed to test whether Coenzyme Q{sub 10} (CoQ{sub 10}) administration has any neuroprotective effect against dichlorvos mediated nigrostriatal neuronal death, {alpha}-synuclein aggregation, and motor dysfunction. Male albino rats were administered dichlorvos by subcutaneous injection at a dose of 2.5 mg/kg body weight over a period of 12 weeks. Results obtained there after showed that dichlorvos exposure leads to enhanced mitochondrial ROS production, {alpha}-synuclein aggregation, decreased dopamine and its metabolite levels resulting in nigrostriatal neurodegeneration. Pretreatment by Coenzyme Q{sub 10} (4.5 mg/kg ip for 12 weeks) to dichlorvos treated animals significantly attenuated the extent of nigrostriatal neuronal damage, in terms of decreased ROS production, increased dopamine and its metabolite levels, and restoration of motor dysfunction when compared to dichlorvos treated animals. Thus, the present study shows that Coenzyme Q{sub 10} administration may attenuate dichlorvos induced nigrostriatal neurodegeneration, {alpha}-synuclein aggregation and motor dysfunction by virtue of its antioxidant action. - Highlights: > CoQ{sub 10} administration attenuates dichlorvos induced nigrostriatal neurodegenaration. > CoQ{sub 10} pre treatment leads to preservation of TH-IR neurons. > CoQ{sub 10} may decrease oxidative damage and {alpha}-synuclin aggregation. > CoQ{sub 10} treatment enhances motor function and protects rats from catalepsy.

  4. Amelioration of neuronal cell death in a spontaneous obese rat model by dietary restriction through modulation of ubiquitin proteasome system.

    PubMed

    Shruthi, Karnam; Reddy, S Sreenivasa; Reddy, P Yadagiri; Shivalingam, Potula; Harishankar, Nemani; Reddy, G Bhanuprakash

    2016-07-01

    Dietary restriction (DR) has been shown to increase longevity, delay onset of aging, reduce DNA damage and oxidative stress and prevent age-related decline of neuronal activity. We previously reported the role of altered ubiquitin proteasome system (UPS) in the neuronal cell death in a spontaneous obese rat model (WNIN/Ob rat). In this study, we investigated the effect of DR on obesity-induced neuronal cell death in a rat model. Two groups of 40-day-old WNIN/Ob rats were either fed ad libitum (Ob) or pair-fed with lean. The lean phenotype of WNIN/Ob rats served as ad libitum control. These animals were maintained for 6.5months on their respective diet regime. At the end of the study, cerebral cortex was collected and markers of UPS, endoplasmic reticulum (ER) stress and autophagy were analyzed by quantitative real-time polymerase chain reaction, immunoblotting and immunohistochemistry. Chymotrypsin-like activity of proteasome was assayed by the fluorimetric method. Apoptotic cells were analyzed by TUNEL assay. DR improved metabolic abnormalities in obese rats. Alterations in UPS (up-regulation of UCHL1, down-regulation of UCHL5, declined proteasomal activity), increased ER stress, declined autophagy and increased expression of α-synuclein, p53 and BAX were observed in obese rats and DR alleviated these changes in obese rats. Further, DR decreased TUNEL-positive cells. In conclusion, DR in obese rats could not only restore the metabolic abnormalities but also preserved neuronal health in the cerebral cortex by preventing alterations in the UPS. PMID:27260470

  5. Role of caspase-10 in the death of acute leukemia cells

    PubMed Central

    Guo, Wenjian; Dong, Aishu; Pan, Xiahui; Lin, Xiaoji; Lin, Ying; He, Muqing; Zhu, Baoling; Jin, Liming; Yao, Rongxing

    2016-01-01

    Autophagy can protect cells from stress, but can also induce cancer cell death. Caspase-10 is now considered to be a factor that is associated with autophagy in cancer. The present study therefore investigated whether caspase-10 affects autophagy in acute leukemia cells. The rates of survival vs. apoptosis in acute leukemia HL-60 and Jurkat cells treated with drugs were tested using cell viability assays and flow cytometry, and the levels of caspase-3 and −10 were tested by western blotting. In HL-60 cells that were treated with chemotherapy drugs combined with a caspase-10 inhibitor, the rate of survival decreased significantly compared with HL-60 cells treated with chemotherapy drugs alone. In contrast, the rate of survival of Jurkat cells treated with chemotherapy drugs combined with the caspase-10 inhibitor increased significantly compared with Jurkat cells treated with chemotherapy drugs alone. The results of the flow cytometry and western blotting showed that the changes in the survival rate may be caused by a change in the amount of apoptosis occurring in the Jurkat cells treated with chemotherapy drugs combined with the caspase-10 inhibitor. However, in HL-60 cells undergoing this combination treatment, the change in the survival rate was not caused by a change in the rate of apoptosis. When HL-60 cells were treated with the chemotherapy drugs combined with the caspase-10 inhibitor and the autophagy inhibitor 3-methyl adenine, the survival rate increased, whereas the rate of apoptosis did not change. These results show that caspase-10 may be associated with autophagy in acute myeloid leukemia cells, but not in acute lymphatic leukemia cells. PMID:27446483

  6. 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

  7. Carbon Monoxide Releasing Molecule-A1 (CORM-A1) Improves Neurogenesis: Increase of Neuronal Differentiation Yield by Preventing Cell Death

    PubMed Central

    Almeida, Ana S.; Soares, Nuno L.; Vieira, Melissa; Gramsbergen, Jan Bert

    2016-01-01

    Cerebral ischemia and neurodegenerative diseases lead to impairment or death of neurons in the central nervous system. Stem cell based therapies are promising strategies currently under investigation. Carbon monoxide (CO) is an endogenous product of heme degradation by heme oxygenase (HO) activity. Administration of CO at low concentrations produces several beneficial effects in distinct tissues, namely anti-apoptotic and anti-inflammatory. Herein the CO role on modulation of neuronal differentiation was assessed. Three different models with increasing complexity were used: human neuroblastoma SH-S5Y5 cell line, human teratocarcinoma NT2 cell line and organotypic hippocampal slice cultures (OHSC). Cell lines were differentiated into post-mitotic neurons by treatment with retinoic acid (RA) supplemented with CO-releasing molecule A1 (CORM-A1). CORM-A1 positively modulated neuronal differentiation, since it increased final neuronal production and enhanced the expression of specific neuronal genes: Nestin, Tuj1 and MAP2. Furthermore, during neuronal differentiation process, there was an increase in proliferative cell number (ki67 mRNA expressing cells) and a decrease in cell death (lower propidium iodide (PI) uptake, limitation of caspase-3 activation and higher Bcl-2 expressing cells). CO supplementation did not increase the expression of RA receptors. In the case of SH-S5Y5 model, small amounts of reactive oxygen species (ROS) generation emerges as important signaling molecules during CO-promoted neuronal differentiation. CO’s improvement of neuronal differentiation yield was validated using OHSC as ex vivo model. CORM-A1 treatment of OHSC promoted higher levels of cells expressing the neuronal marker Tuj1. Still, CORM-A1 increased cell proliferation assessed by ki67 expression and also prevented cell death, which was followed by increased Bcl-2 expression, decreased levels of active caspase-3 and PI uptake. Likewise, ROS signaling emerged as key factors in CO

  8. Absence of Early Neuronal Death in the Olivocochlear System Following Acoustic Overstimulation.

    PubMed

    Reuss, Stefan; Closhen, Christina; Riemann, Randolf; Jaumann, Mirko; Knipper, Marlies; Rüttiger, Lukas; Wolpert, Stephan

    2016-01-01

    This study was conducted to examine possible effects of noise trauma on olivocochlear (OC) neurons. Anesthetized rats were exposed to a continuous 10 kHz pure tone at 120 dB sound pressure level for 2 hrs. The effects of treatment were verified by recordings of auditory brainstem response and distortion product otoacoustic emission. Three or 8 days after acoustic trauma, rats received unilateral injections of an aqueous solution of the retrograde neuronal tracer Fluorogold (FG) into the scala tympani to identify OC neurons (OCN). Five days after FG injection, brains were perfusion-fixed, and brainstem sections were cut and analyzed with respect to FG-labeled neurons. We found that, in both groups, numbers of OCN were similar to that of controls. The incubation of a second set of sections with antibodies against choline-acetyltransferase (the enzyme responsible for acetylcholine synthesis) showed the cholinergic neurons of the brainstem, however, without suggesting differences between groups. Our study, the first to investigate noise trauma effects on identified OCN, revealed that no visible alterations occurred in 2 weeks following trauma, neither in identified OCN nor in choline-acetyltransferase-immunofluorescence. At this time, auditory brainstem response and distortion product otoacoustic emission measurements showed severe signs of hearing loss. The mechanisms leading to hearing loss upon noise trauma apparently do not involve degeneration of OCN. PMID:26452751

  9. Cause and Consequence: Mitochondrial Dysfunction Initiates and Propagates Neuronal Dysfunction, Neuronal Death and Behavioral Abnormalities in Age Associated Neurodegenerative Diseases

    PubMed Central

    Gibson, Gary E.; Starkov, Anatoly; Blass, John P.; Ratan, Rajiv R.; Beal, M. Flint

    2009-01-01

    SUMMARY Age-related neurodegenerative diseases are associated with mild impairment of oxidative metabolism and accumulation of abnormal proteins. Within the cell, the mitochondria appears to be a dominant site for initiation and propagation of disease processes. Shifts in metabolism in response to mild metabolic perturbations may decrease the threshold for irreversible injury in response to ordinarily sub lethal metabolic insults. Mild impairment of metabolism accrue from and lead to increased reactive oxygen species (ROS). Increased ROS change cell signaling via post transcriptional and transcriptional changes. The cause and consequences of mild impairment of mitochondrial metabolism is one focus of this review. Many experiments in tissues from humans support the notion that oxidative modification of the α-ketoglutarate dehydrogenase complex (KGDHC) compromises neuronal energy metabolism and enhance ROS production in Alzheimer’s Disease (AD). These data suggest that cognitive decline in AD derives from the selective tricarboxylic acid (TCA) cycle abnormalities. By contrast in Huntington’s Disease (HD), a movement disorder with cognitive features distinct form AD, complex II + III abnormalities may dominate. These distinct mitochondrial abnormalities culminate in oxidative stress, energy dysfunction, and aberrant homeostasis of cytosolic calcium. Cytosolic calcium, elevations even only transiently, leads to hyperactivity of a number of enzymes. One calcium activated enzyme with demonstrated pathophysiological import in HD and AD is transglutaminase (TGase). TGase is a cross linking enzymes that can modulate transcrption, inactivate metabolic enzymes, and cause aggregation of critical proteins. Recent data indicate that TGase can silence expression of genes involved in compensating for metabolic stress. Altogether, our results suggest that increasing KGDHC via inhibition of TGase or via a host of other strategies to be described would be effective therapeutic

  10. Acute liver failure-induced death of rats is delayed or prevented by blocking NMDA receptors in brain.

    PubMed

    Cauli, Omar; Rodrigo, Regina; Boix, Jordi; Piedrafita, Blanca; Agusti, Ana; Felipo, Vicente

    2008-09-01

    Developing procedures to delay the mechanisms of acute liver failure-induced death would increase patients' survival by allowing time for liver regeneration or to receive a liver for transplantation. Hyperammonemia is a main contributor to brain herniation and mortality in acute liver failure (ALF). Acute ammonia intoxication in rats leads to N-methyl-D-aspartate (NMDA) receptor activation in brain. Blocking these receptors prevents ammonia-induced death. Ammonia-induced activation of NMDA receptors could contribute to ALF-induced death. If this were the case, blocking NMDA receptors could prevent or delay ALF-induced death. The aim of this work was to assess 1) whether ALF leads to NMDA receptors activation in brain in vivo and 2) whether blocking NMDA receptors prevents or delays ALF-induced death of rats. It is shown, by in vivo brain microdialysis, that galactosamine-induced ALF leads to NMDA receptors activation in brain. Blocking NMDA receptors by continuous administration of MK-801 or memantine through miniosmotic pumps affords significant protection against ALF-induced death, increasing the survival time approximately twofold. Also, when liver injury is not 100% lethal (1.5 g/kg galactosamine), blocking NMDA receptors increases the survival rate from 23 to 62%. This supports that blocking NMDA receptors could have therapeutic utility to improve survival of patients with ALF. PMID:18599589

  11. Calpastatin inhibits motor neuron death and increases survival of hSOD1(G93A) mice.

    PubMed

    Rao, Mala V; Campbell, Jabbar; Palaniappan, Arti; Kumar, Asok; Nixon, Ralph A

    2016-04-01

    Amyotrophic lateral sclerosis (ALS) is a progressive motor neuron disease with a poorly understood cause and no effective treatment. Given that calpains mediate neurodegeneration in other pathological states and are abnormally activated in ALS, we investigated the possible ameliorative effects of inhibiting calpain over-activation in hSOD1(G93A) transgenic (Tg) mice in vivo by neuron-specific over-expression of calpastatin (CAST), the highly selective endogenous inhibitor of calpains. Our data indicate that over-expression of CAST in hSOD1(G93A) mice, which lowered calpain activation to levels comparable to wild-type mice, inhibited the abnormal breakdown of cytoskeletal proteins (spectrin, MAP2 and neurofilaments), and ameliorated motor axon loss. Disease onset in hSOD1(G93A) /CAST mice compared to littermate hSOD1(G93A) mice is delayed, which accounts for their longer time of survival. We also find that neuronal over-expression of CAST in hSOD1(G93A) transgenic mice inhibited production of putative neurotoxic caspase-cleaved tau and activation of Cdk5, which have been implicated in neurodegeneration in ALS models, and also reduced the formation of SOD1 oligomers. Our data indicate that inhibition of calpain with CAST is neuroprotective in an ALS mouse model. CAST (encoding calpastatin) inhibits hyperactivated calpain to prevent motor neuron disease operating through a cascade of events as indicated in the schematic, with relevance to amyotrophic lateral sclerosis (ALS). We propose that over-expression of CAST in motor neurons of hSOD1(G93A) mice inhibits activation of CDK5, breakdown of cytoskeletal proteins (NFs, MAP2 and Tau) and regulatory molecules (Cam Kinase IV, Calcineurin A), and disease-causing proteins (TDP-43, α-Synuclein and Huntingtin) to prevent neuronal loss and delay neurological deficits. In our experiments, CAST could also inhibit cleavage of Bid, Bax, AIF to prevent mitochondrial, ER and lysosome-mediated cell death mechanisms. Similarly

  12. Maneb-induced dopaminergic neuronal death is not affected by loss of mitochondrial complex I activity: Results from primary mesencephalic dopaminergic neurons cultured from individual Ndufs4+/+ and Ndufs4-/- mouse embryos

    PubMed Central

    Choi, Won-Seok; Xia, Zhengui

    2014-01-01

    Primary cultures from embryonic mouse ventral mesencephalon are widely used for investigating the mechanisms of dopaminergic neuronal death in Parkinson's disease models. Specifically, single mouse or embryo cultures from littermates can be very useful for comparative studies involving transgenic mice when the neuron cultures are to be prepared before genotyping. However, preparing single mouse embryo culture is technically challenging because of the small number of cells present in the mesencephalon of each embryo (150,000-300,000), of which only 0.5-5% are tyrosine hydroxylase (TH) -positive, dopaminergic neurons. In this study, we optimized the procedure for preparing primary mesencephalic neuron cultures from individual mouse embryos. Mesencephalic neurons that are dissociated delicately, plated on Aclar film coverslips, and incubated in DMEM supplemented with FBS for 5 days and then N2 supplement for 1 day resulted in the best survival of dopaminergic neurons from each embryo. Using this optimized method, we prepared mesencephalic neuron cultures from single Ndufs4+/+ or Ndufs4-/- embryos, and investigated the role of mitochondrial complex I in maneb-induced dopamine neuron death. Our results suggest that maneb toxicity to dopamine neurons is not affected by loss of mitochondrial complex I activity in Ndufs4-/- cultures. PMID:25275677

  13. Reduced neuronal cell death after experimental brain injury in mice lacking a functional alternative pathway of complement activation

    PubMed Central

    Leinhase, Iris; Holers, V Michael; Thurman, Joshua M; Harhausen, Denise; Schmidt, Oliver I; Pietzcker, Malte; Taha, Mohy E; Rittirsch, Daniel; Huber-Lang, Markus; Smith, Wade R; Ward, Peter A; Stahel, Philip F

    2006-01-01

    Background Neuroprotective strategies for prevention of the neuropathological sequelae of traumatic brain injury (TBI) have largely failed in translation to clinical treatment. Thus, there is a substantial need for further understanding the molecular mechanisms and pathways which lead to secondary neuronal cell death in the injured brain. The intracerebral activation of the complement cascade was shown to mediate inflammation and tissue destruction after TBI. However, the exact pathways of complement activation involved in the induction of posttraumatic neurodegeneration have not yet been assessed. In the present study, we investigated the role of the alternative complement activation pathway in contributing to neuronal cell death, based on a standardized TBI model in mice with targeted deletion of the factor B gene (fB-/-), a "key" component required for activation of the alternative complement pathway. Results After experimental TBI in wild-type (fB+/+) mice, there was a massive time-dependent systemic complement activation, as determined by enhanced C5a serum levels for up to 7 days. In contrast, the extent of systemic complement activation was significantly attenuated in fB-/- mice (P < 0.05,fB-/- vs. fB+/+; t = 4 h, 24 h, and 7 days after TBI). TUNEL histochemistry experiments revealed that posttraumatic neuronal cell death was clearly reduced for up to 7 days in the injured brain hemispheres of fB-/- mice, compared to fB+/+ littermates. Furthermore, a strong upregulation of the anti-apoptotic mediator Bcl-2 and downregulation of the pro-apoptotic Fas receptor was detected in brain homogenates of head-injured fB-/- vs. fB+/+ mice by Western blot analysis. Conclusion The alternative pathway of complement activation appears to play a more crucial role in the pathophysiology of TBI than previously appreciated. This notion is based on the findings of (a) the significant attenuation of overall complement activation in head-injured fB-/- mice, as determined by a

  14. 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

  15. 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

  16. 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

  17. Lanosterol induces mitochondrial uncoupling and protects dopaminergic neurons from cell death in a model for Parkinson's disease

    PubMed Central

    Lim, L; Jackson-Lewis, V; Wong, L C; Shui, G H; Goh, A X H; Kesavapany, S; Jenner, A M; Fivaz, M; Przedborski, S; Wenk, M R

    2012-01-01

    Parkinson's disease (PD) is a neurodegenerative disorder marked by the selective degeneration of dopaminergic neurons in the nigrostriatal pathway. Several lines of evidence indicate that mitochondrial dysfunction contributes to its etiology. Other studies have suggested that alterations in sterol homeostasis correlate with increased risk for PD. Whether these observations are functionally related is, however, unknown. In this study, we used a toxin-induced mouse model of PD and measured levels of nine sterol intermediates. We found that lanosterol is significantly (∼50%) and specifically reduced in the nigrostriatal regions of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated mice, indicative of altered lanosterol metabolism during PD pathogenesis. Remarkably, exogenous addition of lanosterol rescued dopaminergic neurons from 1-methyl-4-phenylpyridinium (MPP+)-induced cell death in culture. Furthermore, we observed a marked redistribution of lanosterol synthase from the endoplasmic reticulum to mitochondria in dopaminergic neurons exposed to MPP+, suggesting that lanosterol might exert its survival effect by regulating mitochondrial function. Consistent with this model, we find that lanosterol induces mild depolarization of mitochondria and promotes autophagy. Collectively, our results highlight a novel sterol-based neuroprotective mechanism with direct relevance to PD. PMID:21818119

  18. Ethanol Promotes Thiamine Deficiency-Induced Neuronal Death: Involvement of Double-Stranded RNA-activated Protein Kinase

    PubMed Central

    Ke, Zun-Ji; Wang, Xin; Fan, Zhiqin; Luo, Jia

    2011-01-01

    Background Heavy alcohol consumption causes cerebellar degeneration, and the underlying mechanism is unclear. Chronic alcoholism is usually associated with thiamine deficiency (TD) which is known to induce selective neurodegeneration in the brain. However, the role of TD in alcohol-induced cerebellar degeneration remains to be elucidated. The double-stranded RNA-activated protein kinase (PKR) is a potent antiviral protein. Viral infection or binding to dsRNA causes PKR autophosphorylation and subsequent phosphorylation of the α-subunit of eukaryotic translation factor-2α, leading to inhibition of translation or apoptosis. PKR can also be activated by cellular stresses. Methods In this study, we used an in vitro model, cultured cerebellar granule neurons (CGNs), to investigate the interaction between TD and ethanol and evaluate the contribution of their interaction to neuronal loss. TD was induced by treatment with amprolium in association with ethanol. Cell viability was determined by 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl tetrazolium bromide assay. PKR expression/phosphorylation and subcellular distribution was analyzed with immunoblotting and immunocytochemistry. Results Thiamine deficiency caused death of CGNs but ethanol did not. However, TD plus ethanol induced a much greater cell loss than TD alone. TD-induced PKR phosphorylation and ethanol exposure significantly promoted TD-induced PKR phosphorylation as well as its nuclear translocation. A selective PKR inhibitor not only protected CGNs against TD toxicity, but also abolished ethanol potentiation of TD-induced loss of CGNs. Conclusions Ethanol promoted TD-induced PKR activation and neuronal death. PKR may be a convergent protein that mediates the interaction between TD and ethanol. PMID:19382901

  19. Potentiation of Methylmercury-Induced Death in Rat Cerebellar Granular Neurons Occurs by Further Decrease of Total Intracellular GSH with BDNF via TrkB in Vitro.

    PubMed

    Sakaue, Motoharu; Maki, Takehiro; Kaneko, Takuya; Hemmi, Natsuko; Sekiguchi, Hitomi; Horio, Tomoyo; Kadowaki, Erina; Ozawa, Aisa; Yamamoto, Masako

    2016-01-01

    Brain-derived neurotrophic factor (BDNF) is a principal factor for neurogenesis, neurodevelopment and neural survival through a BDNF receptor, tropomyosin-related kinase (Trk) B, while BDNF can also cause a decrease in the intracellular glutathione (GSH) level. We investigated the exacerbation of methylmercury-induced death of rat cerebellar granular neurons (CGNs) by BDNF in vitro. Since methylmercury can decrease intracellular GSH levels, we hypothesized that a further decrease of the intracellular GSH level is involved in the process of the exacerbation of neuronal cell death. In the present study, we established that in CGN culture, a decrease of the intracellular GSH level was further potentiated with BDNF in the process of the methylmercury-induced neuronal death and also in GSH reducer-induced neuronal death. BDNF treatment promoted the decrease in GSH levels induced by methylmercury and also by L-buthionine sulfoximine (BSO) and diethyl maleate (DEM). The promoting effect of BDNF was observed in a TrkB-vector transformant of the rat neuroblastoma B35 cell line but not in the mock-vector transformant. These results indicate that the exacerbating effect of BDNF on methylmercury-induced neuronal death in cultures of CGNs includes a further decrease of intracellular GSH levels, for which TrkB is essential. PMID:27251509

  20. SIRT1 activating compounds reduce oxidative stress and prevent cell death in neuronal cells

    PubMed Central

    Khan, Reas S.; Fonseca-Kelly, Zoe; Callinan, Catherine; Zuo, Ling; Sachdeva, Mira M.; Shindler, Kenneth S.

    2012-01-01

    Activation of SIRT1, an NAD+-dependent deacetylase, prevents retinal ganglion cell (RGC) loss in optic neuritis, an inflammatory demyelinating optic nerve disease. While SIRT1 deacetylates numerous protein targets, downstream mechanisms of SIRT1 activation mediating this neuroprotective effect are unknown. SIRT1 increases mitochondrial function and reduces oxidative stress in muscle and other cells, and oxidative stress occurs in neuronal degeneration. We examined whether SIRT1 activators reduce oxidative stress and promote mitochondrial function in neuronal cells. Oxidative stress, marked by reactive oxygen species (ROS) accumulation, was induced in RGC-5 cells by serum deprivation, or addition of doxorubicin or hydrogen peroxide, and resulted in significant cell loss. SIRT1 activators resveratrol (RSV) and SRTAW04 reduced ROS levels and promoted cell survival in RGC-5 cells as well as primary RGC cultures. Effects were blocked by SIRT1 siRNA. SIRT1 activators also increased expression of succinate dehydrogenase (SDH), a mitochondrial enzyme, and promoted deacetylation of PGC-1α, a co-enzyme involved in mitochondrial function. Results show SIRT1 activators prevent cell loss by reducing oxidative stress and promoting mitochondrial function in a neuronal cell line. Results suggest SIRT1 activators can mediate neuroprotective effects during optic neuritis by these mechanisms, and they have the potential to preserve neurons in other neurodegenerative diseases that involve oxidative stress. PMID:23293585

  1. (WNK)ing at death: With-no-lysine (Wnk) kinases in neuropathies and neuronal survival.

    PubMed

    Tang, Bor Luen

    2016-07-01

    Members of With-no-lysine (WNK) family of serine-threonine kinase are key regulators of chloride ion transport in diverse cell types, controlling the activity and the surface expression of cation-chloride (Na(+)/K(+)-Cl(-)) co-transporters. Mutations in WNK1 and WNK4 are linked to a hereditary form of hypertension, and WNKs have been extensively investigated pertaining to their roles in renal epithelial ion homeostasis. However, some members of the WNK family and their splice isoforms are also expressed in the mammalian brain, and have been implicated in aspects of hereditary neuropathy as well as neuronal and glial survival. WNK2, which is exclusively enriched in neurons, is well known as an anti-proliferative tumor suppressor. WNK3, on the other hand, appears to promote cell survival as its inhibition enhances neuronal apoptosis. However, loss of WNK3 has been recently shown to reduce ischemia-associated brain damage. In this review, I surveyed the potentially context-dependent roles of WNKs in neurological disorders and neuronal survival. PMID:27131446

  2. Central nervous system haemorrhage causing early death in acute promyelocytic leukaemia

    PubMed Central

    Borowska, Anna; Stelmaszczyk-Emmel, Anna

    2016-01-01

    Acute promyelocytic leukaemia (APL) is a rare type of paediatric leukaemia characterised by a specific genetic mutation and life-threatening coagulopathy. The discovery of all-trans retinoic acid (ATRA), which acts directly on promyelocytic locus-retinoic acid receptor α (PML-RARα) gene product, brought a revolution to the therapy of this disorder. Unfortunately, despite an improvement in the complete remission rate, the early death (ED) rate has not changed significantly, and the haemorrhages remain a major problem. The most common bleeding site, which accounts for about 65-80% of haemorrhages, is the central nervous system. Second in line are pulmonary haemorrhages (32%), while gastrointestinal bleedings are relatively rare. Haemorrhages result from thrombocytopaenia, disseminated intravascular coagulopathy (DIC), and systemic fibrinolysis. Herein we present a boy aged one year and nine months with APL. The patient was not eligible for ATRA administration due to poor clinical condition. He developed bleeding diathesis that presented as disseminated intravascular coagulation (DIC) and led to intracranial haemorrhage, which resulted in the patient's death. PMID:26862315

  3. Kidney and lung injury in irradiated rats protected from acute death by partial-body shielding

    SciTech Connect

    Geraci, J.P.; Jackson, K.L.; Mariano, M.S.; Michieli, B.M. )

    1990-04-01

    Ninety-six CD-1 male rats were exposed to gamma-ray doses (0-25 Gy) in increments of 5 Gy. One femur, the surgically exteriorized GI tract, and the oral cavity were shielded during irradiation to protect against acute mortality from injury to the hematopoietic system, small intestine, and oral cavity. In addition, the thoraxes of half of the animals from each dose group were shielded. At approximately monthly intervals from 2 to 10 months after irradiation the hematocrit, plasma urea nitrogen (PUN), and {sup 51}Cr-EDTA clearance were measured. During the study 20 thorax-shielded and 19 thorax-irradiated animals died. All rats whose thoraxes received 25 Gy irradiation and three out of seven rats whose thoraxes received 20 Gy died 1 to 3 months postirradiation with massive pleural fluid accumulation. Shielding the thoraxes prevented this mode of death at these doses. Kidney injury was judged to be the primary cause of death of all thorax-shielded animals and 15- and 20-Gy thorax-irradiated animals. Animals with kidney damage had elevated PUN and reduced {sup 51}Cr-EDTA clearance and hematocrits. The relative merits of each of these end points in assessing radiation-induced kidney injury after total-body exposure are discussed.

  4. Wild chrysanthemum extract prevents UVB radiation-induced acute cell death and photoaging.

    PubMed

    Sun, Sujiao; Jiang, Ping; Su, Weiting; Xiang, Yang; Li, Jian; Zeng, Lin; Yang, Shuangjuan

    2016-03-01

    Wild chrysanthemum (Chrysanthemum indicum L.) is traditionally used in folk medicine as an anti-inflammatory agent. It is also used in the southwest plateau region of China to prevent ultraviolet-induced skin damage. However, the role and mechanism by which wild chrysanthemum prevents UV-induced skin damage and photoaging have never been investigated in vitro. In the present study, we found that aqueous extracts from wild chrysanthemum strongly reduced high-dose UVB-induced acute cell death of human immortalized keratinocytic HaCat cells. Wild chrysanthemum extract was also demonstrated to reduce low-dose UVB-induced expression of the photoaging-related matrix metalloproteinases MMP-2 and MMP-9. The ROS level elevated by UVB irradiation was strongly attenuated by wild chrysanthemum extract. Further study revealed that wild chrysanthemum extract reduced UVB-triggered ERK1/2 and p38 MAPK phosphorylation and their protective role, which is partially dependent on inhibiting p38 activation. These results suggest that wild chrysanthemum extract can protect the skin from UVB-induced acute skin damage and photoaging by reducing the intracellular reactive oxygen species (ROS) level and inhibiting p38 MAPK phosphorylation. The present study confirmed the protective role of wild chrysanthemum against UV-induced skin disorders in vitro and indicated the possible mechanism. Further study to identify the active components in wild chrysanthemum extract would be useful for developing new drugs for preventing and treating skin diseases, including skin cancer and photoaging, induced by UV irradiation. PMID:25052044

  5. Acute pulmonary emphysema in death by hanging: a morphometric digital study.

    PubMed

    Castiglioni, Claudia; Baumann, Pia; Fracasso, Tony

    2016-09-01

    Acute pulmonary emphysema (APE) has been described in cases of mechanical asphyxia such as ligature or manual strangulation but not in cases of hanging. In this study, we wanted to verify by morphometric digital analysis of lung tissue whether APE occurs in death by hanging.We investigated 16 cases of hanging (eight complete, eight incomplete), 10 cases of freshwater drowning (positive control group), and 10 cases of acute external bleeding (negative control group). Tissue sections were obtained from each pulmonary lobe. For each slide, five fields were randomly selected. The area of every alveolar space was measured by image analysis software. The mean alveolar area (MAA) was calculated for each group.In incomplete hanging, MAA was significantly higher than that observed in complete hanging and similar to the one observed in freshwater drowning.APE in cases of incomplete hanging can be considered as a sign of vitality. The high number of conditions that can cause alveolar distension (that were excluded in this study) limits the applicability of this vital sign in the routine forensic practice. PMID:27448112

  6. Methyl Vitamin B12 but not methylfolate rescues a motor neuron-like cell line from homocysteine-mediated cell death.

    PubMed

    Hemendinger, Richelle A; Armstrong, Edward J; Brooks, Benjamin Rix

    2011-03-15

    Homocysteine is an excitatory amino acid implicated in multiple diseases including amyotrophic lateral sclerosis (ALS). Information on the toxicity of homocysteine in motor neurons is limited and few studies have examined how this toxicity can be modulated. In NSC-34D cells (a hybrid cell line derived from motor neuron-neuroblastoma), homocysteine induces apoptotic cell death in the millimolar range with a TC₅₀ (toxic concentration at which 50% of maximal cell death is achieved) of 2.2 mM, confirmed by activation of caspase 3/7. Induction of apoptosis was independent of short-term reactive oxygen species (ROS) generation. Methyl Vitamin B12 (MeCbl) and methyl tetrahydrofolate (MTHF), used clinically to treat elevated homocysteine levels, were tested for their ability to reverse homocysteine-mediated motor neuron cell death. MeCbl in the micromolar range was able to provide neuroprotection (2 h pretreatment prior to homocysteine) and neurorescue (simultaneous exposure with homocysteine) against millimolar homocysteine with an IC₅₀ (concentration at which 50% of maximal cell death is inhibited) of 0.6 μM and 0.4 μM, respectively. In contrast, MTHF (up to 10 μM) had no effect on homocysteine-mediated cell death. MeCbl inhibited caspase 3/7 activation by homocysteine in a time- and dose-dependent manner, whereas MTHF had no effect. We conclude that MeCbl is effective against homocysteine-induced cell death in motor neurons in a ROS-independent manner, via a reduction in caspase activation and apoptosis. MeCbl decreases Hcy induced motor neuron death in vitro in a hybrid cell line derived from motor neuron-neuroblastoma and may play a role in the treatment of late stage ALS where HCy levels are increased in animal models of ALS. PMID:21237187

  7. Methyl Vitamin B12 but not methylfolate rescues a motor neuron-like cell line from homocysteine-mediated cell death

    SciTech Connect

    Hemendinger, Richelle A. Armstrong, Edward J.; Brooks, Benjamin Rix

    2011-03-15

    Homocysteine is an excitatory amino acid implicated in multiple diseases including amyotrophic lateral sclerosis (ALS). Information on the toxicity of homocysteine in motor neurons is limited and few studies have examined how this toxicity can be modulated. In NSC-34D cells (a hybrid cell line derived from motor neuron-neuroblastoma), homocysteine induces apoptotic cell death in the millimolar range with a TC{sub 50} (toxic concentration at which 50% of maximal cell death is achieved) of 2.2 mM, confirmed by activation of caspase 3/7. Induction of apoptosis was independent of short-term reactive oxygen species (ROS) generation. Methyl Vitamin B12 (MeCbl) and methyl tetrahydrofolate (MTHF), used clinically to treat elevated homocysteine levels, were tested for their ability to reverse homocysteine-mediated motor neuron cell death. MeCbl in the micromolar range was able to provide neuroprotection (2 h pretreatment prior to homocysteine) and neurorescue (simultaneous exposure with homocysteine) against millimolar homocysteine with an IC{sub 50} (concentration at which 50% of maximal cell death is inhibited) of 0.6 {mu}M and 0.4 {mu}M, respectively. In contrast, MTHF (up to 10 {mu}M) had no effect on homocysteine-mediated cell death. MeCbl inhibited caspase 3/7 activation by homocysteine in a time- and dose-dependent manner, whereas MTHF had no effect. We conclude that MeCbl is effective against homocysteine-induced cell death in motor neurons in a ROS-independent manner, via a reduction in caspase activation and apoptosis. MeCbl decreases Hcy induced motor neuron death in vitro in a hybrid cell line derived from motor neuron-neuroblastoma and may play a role in the treatment of late stage ALS where HCy levels are increased in animal models of ALS.

  8. Smac mimetic primes apoptosis-resistant acute myeloid leukaemia cells for cytarabine-induced cell death by triggering necroptosis.

    PubMed

    Chromik, Joerg; Safferthal, Charlotta; Serve, Hubert; Fulda, Simone

    2014-03-01

    The prognosis for patients with acute myeloid leukaemia (AML) is still poor, thus calling for novel treatment strategies. Here, we report that the small-molecule Smac mimetic BV6, which antagonizes Inhibitor of Apoptosis (IAP) proteins, acts in concert with cytarabine (AraC) to trigger cell death in AML cells in a highly synergistic manner (combination index 0.02-0.27). Similarly, BV6 cooperates with AraC to trigger cell death in primary AML samples, underscoring the clinical relevance of our findings. Molecular studies reveal that the TNFα-blocking antibody Enbrel significantly reduces BV6/AraC-induced cell death, demonstrating that an autocrine/paracrine TNFα loop mediates cell death. Furthermore, BV6 and AraC synergize to induce loss of mitochondrial membrane potential, caspase activation and DNA fragmentation, consistent with apoptotic cell death. Nevertheless, the caspase inhibitor zVAD.fmk fails to protect against BV6/AraC-induced cell death. Intriguingly, this cell death upon caspase inhibition is significantly reduced by pharmacological inhibition of two key components of necroptosis signaling, i.e. by RIP1 kinase inhibitor Necrostatin-1 or MLKL inhibitor NSA. Thus, BV6 sensitizes AML cells to AraC-induced cell death and overcomes apoptosis resistance by triggering necroptosis as alternative form of cell death. These findings have important implications for Smac mimetic-based strategies to bypass apoptosis resistance of AML. PMID:24184825

  9. 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

  10. 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

  11. Spiral wave death, breakup induced by ion channel poisoning on regular Hodgkin-Huxley neuronal networks

    NASA Astrophysics Data System (ADS)

    Ma, Jun; Huang, Long; Tang, Jun; Ying, He-Ping; Jin, Wu-Yin

    2012-11-01

    The electric activities of neurons are often affected by ion channel poisoning, in particularly, interrupting normal transduction of signals within the brain. This may be due to changes in conductance and the number of active channels. Tetraethylammonium, for example, is known to cause ion channel poisoning of potassium channels, while tetrodotoxin has similar detrimental effects on sodium channels. The occurrence of spiral waves in neuronal systems was observed frequently in the past, and it was argued that these waves of excitation may play an important role by the propagation of electric signals across the quiescent regions of the brain. In this work, the parameters xk and xNa determine the ratio, with regards to the total number of ion channels, of active potassium and sodium channels, respectively, and they are taken to be representative also for the degree of channel poisoning. In the numerical studies, a well developed stable rotating spiral wave is used as the initial state to be controlled by the ion channel poisoning. We show that, under noise-free conditions, spiral waves are terminated whenever xk and xNa are set lower than a given threshold. However, breakup of spiral wave occurs if the intensity of the channel noise increases. In order to quantify these observations, we use a simple but robust synchronization measure, which captures succinctly the transition from spiral waves to homogeneous neuronal activity and/or broken turbulent state. The critical thresholds can be inferred from the abrupt changes occurring in the corresponding dependencies of synchronization versus the xk and xNa ratios. Furthermore, the sampled membrane potentials of a single neuron are recorded to detect the periodical spiral wave in a feasible way and the results could be dependent of the position of node (or site) to be monitored. Notably, small synchronization factors can be tightly associated to states where the formation of spiral waves is robust to channel poisoning and

  12. Silencer of Death Domains Controls Cell Death through Tumour Necrosis Factor-Receptor 1 and Caspase-10 in Acute Lymphoblastic Leukemia

    PubMed Central

    Khan, Naveed I.; Welschinger, Robert; Basnett, Jordan; Fung, Carina; Rizos, Helen; Bradstock, Kenneth F.; Bendall, Linda J.

    2014-01-01

    Resistance to apoptosis remains a significant problem in drug resistance and treatment failure in malignant disease. NO-aspirin is a novel drug that has efficacy against a number of solid tumours, and can inhibit Wnt signaling, and although we have shown Wnt signaling to be important for acute lymphoblastic leukemia (ALL) cell proliferation and survival inhibition of Wnt signaling does not appear to be involved in the induction of ALL cell death. Treatment of B lineage ALL cell lines and patient ALL cells with NO-aspirin induced rapid apoptotic cell death mediated via the extrinsic death pathway. Apoptosis was dependent on caspase-10 in association with the formation of the death-inducing signaling complex (DISC) incorporating pro-caspase-10 and tumor necrosis factor receptor 1 (TNF-R1). There was no measurable increase in TNF-R1 or TNF-α in response to NO-aspirin, suggesting that the process was ligand-independent. Consistent with this, expression of silencer of death domain (SODD) was reduced following NO-aspirin exposure and lentiviral mediated shRNA knockdown of SODD suppressed expansion of transduced cells confirming the importance of SODD for ALL cell survival. Considering that SODD and caspase-10 are frequently over-expressed in ALL, interfering with these proteins may provide a new strategy for the treatment of this and potentially other cancers. PMID:25061812

  13. Melatonin alleviates hyperthyroidism induced oxidative stress and neuronal cell death in hippocampus of aged female golden hamster, Mesocricetus auratus.

    PubMed

    Rao, Geeta; Verma, Rakesh; Mukherjee, Arun; Haldar, Chandana; Agrawal, Neeraj Kumar

    2016-09-01

    Oxidative stress is a well known phenomenon under hyperthyroid condition that induces various physiological and neural problems with a higher prevalence in females. We, therefore investigated the antioxidant potential of melatonin (Mel) on hyperthyroidism-induced oxidative stress and neuronal cell death in the hippocampus region of brain (cognition and memory centre) of aged female golden hamster, Mesocricetus auratus. Aged female hamsters were randomly divided into four experimental groups (n=7); group-I: control, group-II: Melatonin (5mgkg(-1)day(-1), i.p., for one week), group-III: Hyperthyroid (100μg kg(-1)day(-1), i.p., for two weeks) and group-IV- Hyper+Mel. Hormonal profiles (thyroid and melatonin), activity of antioxidant enzymes (SOD, CAT and GPX), lipid peroxidation level (TBARS) and the specific apoptotic markers (Bax/Bcl-2 ratio and Caspase-3) expression were evaluated. A significant increase in the profile of total thyroid hormone (tT3 and tT4) in hyperthyroidic group as compared to control while tT3 significantly decreased in melatonin treated hyperthyroidic group. However, Mel level significantly decreased in hyperthyroidic group but increased in melatonin treated hyperthyroidic group. Further, the number of immune-positive cells for thyroid hormone receptor-alpha (TR-α) decreased in the hippocampus of hyperthyroidic group and increased in melatonin treated hyperthyroidic group. Profiles of antioxidant enzymes showed a significant decrease in hyperthyroidic group with a simultaneous increase in lipid peroxidation (TBARS). Melatonin treatment to hyperthyroidic group lead to decreased TBARS level with a concomitant increase in antioxidant enzyme activity. Moreover, increased expression of Bax/Bcl-2 ratio and Caspase-3, in hyperthyroidic group had elevated neuronal cell death in hippocampal area and melatonin treatment reduced its expression in hyperthyroidic group. Our findings thus indicate that melatonin reduced the hyperthyroidism

  14. Morphine Enhances HIV-1SF162-Mediated Neuron Death and Delays Recovery of Injured Neurites

    PubMed Central

    Masvekar, Ruturaj R.; El-Hage, Nazira; Hauser, Kurt F.; Knapp, Pamela E.

    2014-01-01

    HIV-1 enters the CNS soon after initial systemic infection; within the CNS parenchyma infected and/or activated perivascular macrophages, microglia and astrocytes release viral and cellular toxins that drive secondary toxicity in neurons and other cell types. Our previous work has largely modeled HIV-neuropathology using the individual viral proteins Tat or gp120, with murine striatal neurons as targets. To model disease processes more closely, the current study uses supernatant from HIV-1-infected cells. Supernatant from HIV-1SF162-infected differentiated-U937 cells (HIV+sup) was collected and p24 level was measured by ELISA to assess the infection. Injection drug abuse is a significant risk factor for HIV-infection, and opiate drug abusers show increased HIV-neuropathology, even with anti-retroviral treatments. We therefore assessed HIV+sup effects on neuronal survival and neurite growth/pruning with or without concurrent exposure to morphine, an opiate that preferentially acts through µ-opioid receptors. Effects of HIV+sup ± morphine were assessed on neuronal populations, and also by time-lapse imaging of individual cells. HIV+sup caused dose-dependent toxicity over a range of p24 levels (10–500 pg/ml). Significant interactions occurred with morphine at lower p24 levels (10 and 25 pg/ml), and GSK3β was implicated as a point of convergence. In the presence of glia, selective neurotoxic measures were significantly enhanced and interactions with morphine were also augmented, perhaps related to a decreased level of BDNF. Importantly, the arrest of neurite growth that occurred with exposure to HIV+sup was reversible unless neurons were continuously exposed to morphine. Thus, while reducing HIV-infection levels may be protective, ongoing exposure to opiates may limit recovery. Opiate interactions observed in this HIV-infective environment were similar, though not entirely concordant, with Tat/gp120 interactions reported previously, suggesting unique interactions

  15. 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)

  16. Rapid generation of mitochondrial superoxide induces mitochondrion-dependent but caspase-independent cell death in hippocampal neuronal cells that morphologically resembles necroptosis

    SciTech Connect

    Fukui, Masayuki; Choi, Hye Joung; Zhu, Bao Ting

    2012-07-15

    Studies in recent years have revealed that excess mitochondrial superoxide production is an important etiological factor in neurodegenerative diseases, resulting from oxidative modifications of cellular lipids, proteins, and nucleic acids. Hence, it is important to understand the mechanism by which mitochondrial oxidative stress causes neuronal death. In this study, the immortalized mouse hippocampal neuronal cells (HT22) in culture were used as a model and they were exposed to menadione (also known as vitamin K{sub 3}) to increase intracellular superoxide production. We found that menadione causes preferential accumulation of superoxide in the mitochondria of these cells, along with the rapid development of mitochondrial dysfunction and cellular ATP depletion. Neuronal death induced by menadione is independent of the activation of the MAPK signaling pathways and caspases. The lack of caspase activation is due to the rapid depletion of cellular ATP. It was observed that two ATP-independent mitochondrial nucleases, namely, AIF and Endo G, are released following menadione exposure. Silencing of their expression using specific siRNAs results in transient suppression (for ∼ 12 h) of mitochondrial superoxide-induced neuronal death. While suppression of the mitochondrial superoxide dismutase expression markedly sensitizes neuronal cells to mitochondrial superoxide-induced cytotoxicity, its over-expression confers strong protection. Collectively, these findings showed that many of the observed features associated with mitochondrial superoxide-induced cell death, including caspase independency, rapid depletion of ATP level, mitochondrial release of AIF and Endo G, and mitochondrial swelling, are distinctly different from those of apoptosis; instead they resemble some of the known features of necroptosis. -- Highlights: ► Menadione causes mitochondrial superoxide accumulation and injury. ► Menadione-induced cell death is caspase-independent, due to rapid depletion of

  17. X-ray-induced cell death in the developing hippocampal complex involved neurons and requires protein synthesis

    SciTech Connect

    Ferrer, I.; Serrano, T.; Alcantara, S.; Tortosa, A.; Graus, F.

    1993-07-01

    Sprague-Dawley rats aged 1 or 15 days were irradiated with a single dose of 200 cGy X-rays and killed at different intervals from 3 to 48 hours (h). Dying cells were recognized by their shrunken and often fragmented nuclei and less damaged cytoplasm in the early stages. On the basis of immunocytochemical markers, dying cells probably represented a heterogeneous population which included neurons and immature cells. In rats aged 1 day the number of dying cells rapidly increased in the hippocampal complex with peak values 6 h after irradiation. This was following by a gentle decrease to reach normal values 48 h after irradiation. The most severely affected regions were the subplate and the cellular layer of the subiculum, gyrus dentatus and hilus, and the stratum oriens and pyramidale of the hippocampus (CA1 more affected than CA2, and this more affected than CA3). X-ray-induced cell death was abolished with an injection of cycloheximide (2 [mu]g/g i.p.) given at the time of irradiation. X-ray-induced cell death was not changed after the intraventicular administration of nerve growth factor (NGF; 10 [mu]g in saline) at the time of irradiation. Cell death was not induced by X-irradiation in rats aged 15 days. These results indicate that X-ray-induced cell death in the hippocampal complex of the developing rat is subjected to determinate temporal and regional patterns of vulnerability; it is an active process mediated by protein synthesis but probably not dependent on NGF. 60 refs., 5 figs.

  18. Motor neuron cell death in wobbler mutant mice follows overexpression of the G-protein-coupled, protease-activated receptor for thrombin.

    PubMed Central

    Festoff, B. W.; D'Andrea, M. R.; Citron, B. A.; Salcedo, R. M.; Smirnova, I. V.; Andrade-Gordon, P.

    2000-01-01

    BACKGROUND: Mechanisms underlying neurodegeneration are actively sought for new therapeutic strategies. Transgenic, knockout and genetic mouse models greatly aid our understanding of the mechanisms for neuronal cell death. A naturally occurring, autosomal recessive mutant, known as wobbler, and mice transgenic for familial amyotrophic lateral sclerosis (FALS) superoxide dismutase (SOD)1 mutations are available, but the molecular mechanisms remain equally unknown. Both phenotypes are detectable after birth. Wobbler is detectable in the third week of life, when homozygotes (wr/wr) exhibit prominent gliosis and significant motor neuron loss in the cervical, but not in lumbar, spinal cord segments. To address molecular mechanisms, we evaluated "death signals" associated with the multifunctional serine protease, thrombin, which leads to apoptotic motor neuronal cell death in culture by cleavage of a G-protein coupled, protease-activated receptor 1 (PAR-1). MATERIALS AND METHODS: Thrombin activities were determined with chromogenic substrate assays, Western immunoblots and immunohistochemistry were performed with anti-PAR-1 to observe localizations of the receptor and anti-GFAP staining was used to monitor astrocytosis. PAR-1 mRNA levels and locations were determined by reverse transcription polymerase chain reaction (qRT-PCR) and in situ hybridizations. Cell death was monitored with in situ DNA fragmentation assays. RESULTS: In preliminary studies we found a 5-fold increase in PAR-1 mRNA in cervical spinal cords from wr/wr, compared with wild-type (wt) littermates. Our current studies suggested that reactive astrocytosis and motor neuron cell death were causally linked with alterations in thrombin signaling. PAR-1 protein expression was increased, as demonstrated by immunocytochemistry and confirmed with in situ hybridization, in phenotypic wr/wr motor neurons, compared with wt, but not in astrocytes. This increase was much greater in cervical, compared with lumbar

  19. 3,5,6,7,8,3',4'-Heptamethoxyflavone, a citrus flavonoid, on protection against memory impairment and neuronal cell death in a global cerebral ischemia mouse model.

    PubMed

    Okuyama, Satoshi; Morita, Mayu; Miyoshi, Kazuhiro; Nishigawa, Yuki; Kaji, Miki; Sawamoto, Atsushi; Terugo, Tsukasa; Toyoda, Nobuki; Makihata, Nahomi; Amakura, Yoshiaki; Yoshimura, Morio; Nakajima, Mitsunari; Furukawa, Yoshiko

    2014-05-01

    The present study evaluated the effects of treatment with the citrus flavonoid, 3,5,6,7,8,3',4'-heptamethoxyflavone (HMF) on protection against memory impairment and neuronal death in a global cerebral ischemia mouse model. The results showed that HMF, administrated for three days immediately after ischemic surgery, protected against ischemia-induced memory dysfunction, rescued neuronal cell death in the CA1 cell layer, increased the production of BDNF, stimulated the autophosphorylation of CaMK II and suppressed microglial activation in the hippocampus. These results suggest that HMF has a neuroprotective effect after brain ischemia by inducing BDNF production and anti-inflammatory effects. PMID:24657445

  20. Quantitative relationships between huntingtin levels, polyglutamine length, inclusion body formation, and neuronal death provide novel insight into Huntington’s disease molecular pathogenesis

    PubMed Central

    Miller, Jason; Arrasate, Montserrat; Shaby, Benjamin A.; Mitra, Siddhartha; Masliah, Eliezer; Finkbeiner, Steven

    2010-01-01

    An expanded polyglutamine (polyQ) stretch in the protein huntingtin (htt) induces self-aggregation into inclusion bodies (IBs) and causes Huntington’s disease (HD). Defining precise relationships between early observable variables and neuronal death at the molecular and cellular levels should improve our understanding of HD pathogenesis. Here, we utilized an automated microscope that can track thousands of neurons individually over their entire lifetime to quantify interconnected relationships between early variables, such as htt levels, polyQ length, and IB formation, and neuronal death in a primary striatal model of HD. The resulting model revealed that: mutant htt increases the risk of death by tonically interfering with homeostatic coping mechanisms rather than producing accumulated damage to the neuron; htt toxicity is saturable; the rate limiting steps for inclusion body formation and death can be traced to different conformational changes in monomeric htt; and IB formation reduces the impact of a neuron’s starting levels of htt on its risk of death. Finally, the model that emerges from our quantitative measurements places critical limits on the potential mechanisms by which mutant htt might induce neurodegeneration, which should help direct future research. PMID:20685997

  1. 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

  2. TESTIN Induces Rapid Death and Suppresses Proliferation in Childhood B Acute Lymphoblastic Leukaemia Cells

    PubMed Central

    Weeks, Robert J.; Ludgate, Jackie L.; LeMée, Gwenn; Morison, Ian M.

    2016-01-01

    Background Childhood acute lymphoblastic leukaemia (ALL) is the most common malignancy in children. Despite high cure rates, side effects and late consequences of the intensive treatments are common. Unquestionably, the identification of new therapeutic targets will lead to safer, more effective treatments. We identified TES promoter methylation and transcriptional silencing as a very common molecular abnormality in childhood ALL, irrespective of molecular subtype. The aims of the present study were to demonstrate that TES promoter methylation is aberrant, to determine the effects of TES re-expression in ALL, and to determine if those effects are mediated via TP53 activity. Methods Normal fetal and adult tissue DNA was isolated and TES promoter methylation determined by Sequenom MassARRAY. Quantitative RT-PCR and immunoblot were used to confirm re-expression of TES in ALL cell lines after 5’-aza-2’-deoxycytidine (decitabine) exposure or transfection with TES expression plasmids. The effects of TES re-expression on ALL cells were investigated using standard cell proliferation, cell death and cell cycle assays. Results In this study, we confirm that the TES promoter is unmethylated in normal adult and fetal tissues. We report that decitabine treatment of ALL cell lines results in demethylation of the TES promoter and attendant expression of TES mRNA. Re-expression of TESTIN protein in ALL cells using expression plasmid transfection results in rapid cell death or cell cycle arrest independent of TP53 activity. Conclusions These results suggest that TES is aberrantly methylated in ALL and that re-expression of TESTIN has anti-leukaemia effects which point to novel therapeutic opportunities for childhood ALL. PMID:26985820

  3. Mitochondrial Bioenergetic Alterations in Mouse Neuroblastoma Cells Infected with Sindbis Virus: Implications to Viral Replication and Neuronal Death

    PubMed Central

    Silva da Costa, Leandro; Pereira da Silva, Ana Paula; Da Poian, Andrea T.; El-Bacha, Tatiana

    2012-01-01

    The metabolic resources crucial for viral replication are provided by the host. Details of the mechanisms by which viruses interact with host metabolism, altering and recruiting high free-energy molecules for their own replication, remain unknown. Sindbis virus, the prototype of and most widespread alphavirus, causes outbreaks of arthritis in humans and serves as a model for the study of the pathogenesis of neurological diseases induced by alphaviruses in mice. In this work, respirometric analysis was used to evaluate the effects of Sindbis virus infection on mitochondrial bioenergetics of a mouse neuroblastoma cell lineage, Neuro 2a. The modulation of mitochondrial functions affected cellular ATP content and this was synchronous with Sindbis virus replication cycle and cell death. At 15 h, irrespective of effects on cell viability, viral replication induced a decrease in oxygen consumption uncoupled to ATP synthesis and a 36% decrease in maximum uncoupled respiration, which led to an increase of 30% in the fraction of oxygen consumption used for ATP synthesis. Decreased proton leak associated to complex I respiration contributed to the apparent improvement of mitochondrial function. Cellular ATP content was not affected by infection. After 24 h, mitochondria dysfunction was clearly observed as maximum uncoupled respiration reduced 65%, along with a decrease in the fraction of oxygen consumption used for ATP synthesis. Suppressed respiration driven by complexes I- and II-related substrates seemed to play a role in mitochondrial dysfunction. Despite the increase in glucose uptake and glycolytic flux, these changes were followed by a 30% decrease in ATP content and neuronal death. Taken together, mitochondrial bioenergetics is modulated during Sindbis virus infection in such a way as to favor ATP synthesis required to support active viral replication. These early changes in metabolism of Neuro 2a cells may form the molecular basis of neuronal dysfunction and Sindbis

  4. 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

  5. S-Nitrosylation—Mediated Redox Transcriptional Switch Modulates Neurogenesis and Neuronal Cell Death

    PubMed Central

    Okamoto, Shu-ichi; Nakamura, Tomohiro; Cieplak, Piotr; Chan, Shing Fai; Kalashnikova, Evgenia; Liao, Lujian; Saleem, Sofiyan; Han, Xuemei; Clemente, Arjay; Nutter, Anthony; Sances, Sam; Brechtel, Christopher; Haus, Daniel; Haun, Florian; Sanz-Blasco, Sara; Huang, Xiayu; Li, Hao; Zaremba, Jeffrey D.; Cui, Jiankun; Gu, Zezong; Nikzad, Rana; Harrop, Anne; McKercher, Scott R.; Godzik, Adam; Yates, John R.; Lipton, Stuart A.

    2014-01-01

    SUMMARY Redox-mediated posttranslational modifications represent a molecular switch that controls major mechanisms of cell function. Nitric oxide (NO) can mediate redox reactions via S-nitrosylation, representing transfer of an NO group to a critical protein thiol. NO is known to modulate neurogenesis and neuronal survival in various brain regions in disparate neurodegenerative conditions. However, a unifying molecular mechanism linking these phenomena remains unknown. Here we report that S-nitrosylation of myocyte enhancer factor 2 (MEF2) transcription factors acts as a redox switch to inhibit both neurogenesis and neuronal survival. Structure-based analysis reveals that MEF2 dimerization creates a pocket, facilitating S-nitrosylation at an evolutionally conserved cysteine residue in the DNA binding domain. S-Nitrosylation disrupts MEF2-DNA binding and transcriptional activity, leading to impaired neurogenesis and survival in vitro and in vivo. Our data define a novel molecular switch whereby redox-mediated posttranslational modification controls both neurogenesis and neurodegeneration via a single transcriptional signaling cascade. PMID:25001280

  6. Protective effects of onion-derived quercetin on glutamate-mediated hippocampal neuronal cell death

    PubMed Central

    Yang, Eun-Ju; Kim, Geum-Soog; Kim, Jeong Ah; Song, Kyung-Sik

    2013-01-01

    Background: Neurodegenerative diseases are characterized by progressive neuron degeneration in specific functional systems of the central or peripheral nervous system. This study investigated the protective effects of quercetin isolated from onion on neuronal cells and its protective mechanisms against glutamate-induced apoptosis in HT22 cells. Materials and Methods: HT22 cells were cultured to study the neuroprotective mechanism of quercetin against glutamate-mediated oxidative stress. The intracellular reactive oxygen species (ROS) level and mitochondrial membrane potential (ΔΨm) were measured. The protein expression of calpain, spectrin, Bcl-2, Bax, Bid, cytochrome c, and mitogen-activated protein kinases (MAPKs) was evaluated by Western blotting. Results: Quercetin had a protective effect by reducing both intracellular ROS overproduction and glutamate-mediated Ca2+ influx. These effects were due to the downregulation of several apoptosis-related biochemical markers. Calpain expression was reduced and spectrin cleavage was inhibited by quercetin in glutamate-exposed HT22 cells. Disruption of the mitochondrial membrane potential (ΔΨm), activation of the pro-apoptotic proteins Bid and Bax, and cytochrome c release in response to glutamate-induced oxidative stress were reduced. Quercetin also suppressed phosphorylation of MAPKs. Conclusion: This is the first report on the detailed mechanisms of the protective effect of quercetin on HT22 cells. Onion extract and quercetin may be useful for preventing or treating neurodegenerative disorders. PMID:24124281

  7. S-nitrosylation-mediated redox transcriptional switch modulates neurogenesis and neuronal cell death.

    PubMed

    Okamoto, Shu-Ichi; Nakamura, Tomohiro; Cieplak, Piotr; Chan, Shing Fai; Kalashnikova, Evgenia; Liao, Lujian; Saleem, Sofiyan; Han, Xuemei; Clemente, Arjay; Nutter, Anthony; Sances, Sam; Brechtel, Christopher; Haus, Daniel; Haun, Florian; Sanz-Blasco, Sara; Huang, Xiayu; Li, Hao; Zaremba, Jeffrey D; Cui, Jiankun; Gu, Zezong; Nikzad, Rana; Harrop, Anne; McKercher, Scott R; Godzik, Adam; Yates, John R; Lipton, Stuart A

    2014-07-10

    Redox-mediated posttranslational modifications represent a molecular switch that controls major mechanisms of cell function. Nitric oxide (NO) can mediate redox reactions via S-nitrosylation, representing transfer of an NO group to a critical protein thiol. NO is known to modulate neurogenesis and neuronal survival in various brain regions in disparate neurodegenerative conditions. However, a unifying molecular mechanism linking these phenomena remains unknown. Here, we report that S-nitrosylation of myocyte enhancer factor 2 (MEF2) transcription factors acts as a redox switch to inhibit both neurogenesis and neuronal survival. Structure-based analysis reveals that MEF2 dimerization creates a pocket, facilitating S-nitrosylation at an evolutionally conserved cysteine residue in the DNA binding domain. S-Nitrosylation disrupts MEF2-DNA binding and transcriptional activity, leading to impaired neurogenesis and survival in vitro and in vivo. Our data define a molecular switch whereby redox-mediated posttranslational modification controls both neurogenesis and neurodegeneration via a single transcriptional signaling cascade. PMID:25001280

  8. Role of Ca2+ channels in the ability of membrane depolarization to prevent neuronal death induced by trophic-factor deprivation: evidence that levels of internal Ca2+ determine nerve growth factor dependence of sympathetic ganglion cells.

    PubMed Central

    Koike, T; Martin, D P; Johnson, E M

    1989-01-01

    Sympathetic neurons depend on nerve growth factor (NGF) for their survival both in vivo and in vitro; these cells die upon acute deprivation of NGF. We studied the effects of agents that cause membrane depolarization on neuronal survival after NGF deprivation. High-K+ medium (greater than or equal to 33 mM) prevented cell death; the effect of K+ was dose-dependent (EC50 = 21 mM). The protection by high K+ was abolished either by withdrawal of extracellular Ca2+ or by preloading the cells with a Ca2+ chelator. The involvement of Ca2+ flux across membranes in high-K+ saving of NGF-deprived neurons was also supported by experiments using Ca2+-channel antagonists and agonists. The Ca2+ antagonists nimodipine and nifedipine effectively blocked the survival-promoting effect of high K+. The Ca2+ agonists Bay K 8644 and (S)-202-791 did not by themselves save neurons from NGF deprivation but did strongly augment the effect of high K+; EC50 was shifted from 21 mM to 13 mM. These data suggest that dihydropyridine-sensitive L-type Ca2+ channels play a major role in the high-K+ saving. The depolarizing agents choline (EC50 = 1 mM) and carbamoylcholine (EC50 = 1 microM), acting through nicotinic cholinergic receptors, also rescued NGF-deprived neurons. The saving effect of nicotinic agonists was not blocked by withdrawal of extracellular Ca2+ but was counteracted by a chelator of intracellular Ca2+, suggesting the possible involvement of Ca2+ release from internal stores. Based on these findings we propose a "Ca2+ set-point hypothesis" for the degree of trophic-factor dependence of sympathetic neurons in vitro. Images PMID:2548215

  9. Ginkgo biloba Prevents Transient Global Ischemia-Induced Delayed Hippocampal Neuronal Death Through Antioxidant and Anti-inflammatory Mechanism

    PubMed Central

    Tulsulkar, Jatin; Shah, Zahoor A.

    2012-01-01

    We have previously reported neuroprotective properties of Ginkgo biloba/EGb 761® (EGb 761) in transient and permanent mouse models of brain ischemia. In a quest to extend our studies on EGB 761 and its constituents further, we used a model of transient global ischemia induced delayed hippocampal neuronal death and inflammation. Mice pretreated with different test drugs for 7 days were subjected to eight-minute bilateral common carotid artery occlusion (tBCCAO) at day 8. After 7 days of reperfusion, mice brains were dissected out for TUNEL assay and immunohistochemistry. In-situ detection of fragmented DNA (TUNEL staining) showed that out of all test drugs, only EGb 761 (13.6% ± 3.2) pretreatment protected neurons in the hippocampus against global ischemia (vs. vehicle, 85.1% ± 9.9; p < 0.05). Immunofluorescence-based studies demonstrated that pretreatment with EGb 761 upregulated the expression levels of heme oxygenase 1 (HO1), nuclear factor erythroid 2-related factor 2 (Nrf2), and vascular endothelial growth factor (VEGF) as compared to the vehicle group. In addition, increased number of activated astrocytes and microglia in the vehicle group was observed to be significantly lower in the EGb 761 pretreated group. Together, these results suggest that EGb 761 is a multifunctional neuroprotective agent, and the protection is in part associated with activation of the HO1/Nrf2 pathway, upregulation of VEGF and downregulation of inflammatory mediators such as astrocytes and microglia. PMID:23228346

  10. Blockade of the Interaction of Calcineurin with FOXO in Astrocytes Protects Against Amyloid-β-Induced Neuronal Death.

    PubMed

    Fernandez, Ana M; Hervas, Ruben; Dominguez-Fraile, Manuel; Garrido, Victoria Navarro; Gomez-Gutierrez, Patricia; Vega, Miguel; Vitorica, Javier; Perez, Juan J; Torres Aleman, Ignacio

    2016-04-12

    Astrocytes actively participate in neuro-inflammatory processes associated to Alzheimer's disease (AD), and other brain pathologies. We recently showed that an astrocyte-specific intracellular signaling pathway involving an interaction of the phosphatase calcineurin with the transcription factor FOXO3 is a major driver in AD-associated pathological inflammation, suggesting a potential new druggable target for this devastating disease. We have now developed decoy molecules to interfere with calcineurin/FOXO3 interactions, and tested them in astrocytes and neuronal co-cultures exposed to amyloid-β (Aβ) toxicity. We observed that interference of calcineurin/FOXO3 interactions exerts a protective action against Aβ-induced neuronal death and favors the production of a set of growth factors that we hypothesize form part of a cytoprotective pathway to resolve inflammation. Furthermore, interference of the Aβ-induced interaction of calcineurin with FOXO3 by decoy compounds significantly decreased amyloid-β protein precursor (AβPP) synthesis, reduced the AβPP amyloidogenic pathway, resulting in lower Aβ levels, and blocked the expression of pro-inflammatory cytokines TNFα and IL-6 in astrocytes. Collectively, these data indicate that interrupting pro-inflammatory calcineurin/FOXO3 interactions in astrocytes triggered by Aβ accumulation in brain may constitute an effective new therapeutic approach in AD. Future studies with intranasal delivery, or brain barrier permeable decoy compounds, are warranted. PMID:27079728

  11. Decreased ribosomal DNA transcription in dorsal raphe nucleus neurons differentiates between suicidal and non-suicidal death.

    PubMed

    Krzyżanowska, Marta; Steiner, Johann; Karnecki, Karol; Kaliszan, Michał; Brisch, Ralf; Wiergowski, Marek; Braun, Katharina; Jankowski, Zbigniew; Gos, Tomasz

    2016-04-01

    An involvement of the central serotonergic system has been implicated in the pathogenesis of suicide. The dorsal raphe nucleus (DRN) is the main source of serotonergic innervation of forebrain limbic structures disturbed in suicidal behaviour. The study was carried out on paraffin-embedded brainstem blocks containing the DRN obtained from 27 suicide completers (predominantly violent) with unknown psychiatric diagnosis and 30 non-suicidal controls. The transcriptional activity of ribosomal DNA (rDNA) in DRN neurons as a surrogate marker of protein biosynthesis was evaluated by the AgNOR silver staining method. Significant decreases in AgNOR parameters suggestive of attenuated rDNA activity were found in the cumulative analysis of all DRN subnuclei in suicide victims versus controls (U test P values < 0.00001). Our findings suggest that the decreased activity of rDNA transcription in DRN neurons plays an important role in suicide pathogenesis. The method accuracy represented by the area under receiver operating characteristic curve (>80 %) suggests a diagnostic value of the observed effect. However, the possible application of the method in forensic differentiation diagnostics between suicidal and non-suicidal death needs further research. PMID:26590846

  12. 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

  13. 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

  14. TLR4-activated microglia require IFN-γ to induce severe neuronal dysfunction and death in situ.

    PubMed

    Papageorgiou, Ismini E; Lewen, Andrea; Galow, Lukas V; Cesetti, Tiziana; Scheffel, Jörg; Regen, Tommy; Hanisch, Uwe-Karsten; Kann, Oliver

    2016-01-01

    Microglia (tissue-resident macrophages) represent the main cell type of the innate immune system in the CNS; however, the mechanisms that control the activation of microglia are widely unknown. We systematically explored microglial activation and functional microglia-neuron interactions in organotypic hippocampal slice cultures, i.e., postnatal cortical tissue that lacks adaptive immunity. We applied electrophysiological recordings of local field potential and extracellular K(+) concentration, immunohistochemistry, design-based stereology, morphometry, Sholl analysis, and biochemical analyses. We show that chronic activation with either bacterial lipopolysaccharide through Toll-like receptor 4 (TLR4) or leukocyte cytokine IFN-γ induces reactive phenotypes in microglia associated with morphological changes, population expansion, CD11b and CD68 up-regulation, and proinflammatory cytokine (IL-1β, TNF-α, IL-6) and nitric oxide (NO) release. Notably, these reactive phenotypes only moderately alter intrinsic neuronal excitability and gamma oscillations (30-100 Hz), which emerge from precise synaptic communication of glutamatergic pyramidal cells and fast-spiking, parvalbumin-positive GABAergic interneurons, in local hippocampal networks. Short-term synaptic plasticity and extracellular potassium homeostasis during neural excitation, also reflecting astrocyte function, are unaffected. In contrast, the coactivation of TLR4 and IFN-γ receptors results in neuronal dysfunction and death, caused mainly by enhanced microglial inducible nitric oxide synthase (iNOS) expression and NO release, because iNOS inhibition is neuroprotective. Thus, activation of TLR4 in microglia in situ requires concomitant IFN-γ receptor signaling from peripheral immune cells, such as T helper type 1 and natural killer cells, to unleash neurotoxicity and inflammation-induced neurodegeneration. Our findings provide crucial mechanistic insight into the complex process of microglia activation, with

  15. Multiple domains in the C-terminus of NMDA receptor GluN2B subunit contribute to neuronal death following in vitro ischemia.

    PubMed

    Vieira, Marta M; Schmidt, Jeannette; Ferreira, Joana S; She, Kevin; Oku, Shinichiro; Mele, Miranda; Santos, Armanda E; Duarte, Carlos B; Craig, Ann Marie; Carvalho, Ana Luísa

    2016-05-01

    Global cerebral ischemia induces selective degeneration of specific subsets of neurons throughout the brain, particularly in the hippocampus and cortex. One of the major hallmarks of cerebral ischemia is excitotoxicity, characterized by overactivation of glutamate receptors leading to intracellular Ca(2+) overload and ultimately neuronal demise. N-methyl-d-aspartate receptors (NMDARs) are considered to be largely responsible for excitotoxic injury due to their high Ca(2+) permeability. In the hippocampus and cortex, these receptors are most prominently composed of combinations of two GluN1 subunits and two GluN2A and/or GluN2B subunits. Due to the controversy regarding the differential role of GluN2A and GluN2B subunits in excitotoxic cell death, we investigated the role of GluN2B in the activation of pro-death signaling following an in vitro model of global ischemia, oxygen and glucose deprivation (OGD). For this purpose, we used GluN2B(-/-) mouse cortical cultures and observed that OGD-induced damage was reduced in these neurons, and partially prevented in wild-type rat neurons by a selective GluN2B antagonist. Notably, we found a crucial role of the C-terminal domain of the GluN2B subunit in triggering excitotoxic signaling. Indeed, expression of YFP-GluN2B C-terminus mutants for the binding sites to post-synaptic density protein 95 (PSD95), Ca(2+)-calmodulin kinase IIα (CaMKIIα) or clathrin adaptor protein 2 (AP2) failed to mediate neuronal death in OGD conditions. We focused on the GluN2B-CaMKIIα interaction and found a determinant role of this interaction in OGD-induced death. Inhibition or knock-down of CaMKIIα exerted a neuroprotective effect against OGD-induced death, whereas overexpression of this kinase had a detrimental effect. Importantly, in comparison with neurons overexpressing wild-type CaMKIIα, neurons overexpressing a mutant form of the kinase (CaMKII-I205K), unable to interact with GluN2B, were partially protected against OGD-induced damage

  16. Acute alcohol intoxication and suicide: a gender-stratified analysis of the National Violent Death Reporting System

    PubMed Central

    Kaplan, Mark S; McFarland, Bentson H; Huguet, Nathalie; Conner, Kenneth; Caetano, Raul; Giesbrecht, Norman; Nolte, Kurt B

    2013-01-01

    Objectives Although it is well known that people with alcohol dependence are at a markedly elevated risk for suicide, much less is known about the role of acute alcohol use in suicidal behaviours. The primary aims of this epidemiological study were to assess the prevalence and factors associated with acute alcohol intoxication among 57 813 suicide decedents in 16 states. Methods Data from the restricted National Violent Death Reporting System 2003–2009 for male and female suicide decedents aged 18 years and older were analysed by multiple logistic regression to compare decedents with and without acute alcohol intoxication (defined as blood alcohol concentration (BAC) ≥0.08 g/dl). Results Among men, those who were younger, American Indian/Alaska Native, Hispanic, veterans, of lower educational attainment, deceased from a self-inflicted firearm injury or hanging/suffocation and residing in rural areas were more likely to have been intoxicated at the time of death. Among women, the factors associated with a BAC ≥0.08 g/dl were younger age, being American Indian/Alaska Native, and using a firearm, hanging/suffocation or falling as method of death. Conclusions In both men and women, alcohol intoxication was associated with violent methods of suicide and declined markedly with age, suggesting that addressing risks associated with acute alcohol use may be of the greatest aid in the prevention of violent suicides among young and middle age adults. PMID:22627777

  17. Acute death associated with Citrobacter freundii infection in an African elephant (Loxodonta africana).

    PubMed

    Ortega, Joaquín; Corpa, Juan M; Orden, José A; Blanco, Jorge; Carbonell, María D; Gerique, Amalia C; Latimer, Erin; Hayward, Gary S; Roemmelt, Andreas; Kraemer, Thomas; Romey, Aurore; Kassimi, Labib B; Casares, Miguel

    2015-09-01

    A 21-year-old male African elephant (Loxodonta africana) died suddenly with no previous medical history. Grossly, there were severe multifocal epicardial and endocardial hemorrhages of the atria and ventricles, hydropericardium, multifocal pleural hemorrhages, and severe pulmonary congestion and edema. Histologically, there was fibrinoid vasculitis and thrombosis in the heart and lung and myocardial necrosis. Citrobacter freundii was isolated in abundance in pure culture from liver and heart samples. Low levels of multiples types of elephant endotheliotropic herpesvirus (EEHV-6, EEHV-2B, and EEHV-3A) were detected in spleen samples, but not in heart samples. The levels of EEHV DNA found were much lower than those usually associated with acute EEHV hemorrhagic disease, and many other genomic loci that would normally be found in such cases were evidently below the level of detection. Therefore, these findings are unlikely to indicate lethal EEHV disease. Polymerase chain reaction for encephalomyocarditis virus (EMCV) and toxicology for oleander (Nerium oleander) were negative. Stress, resulting from recent transport, and antimicrobial therapy may have contributed to the death of this animal. PMID:26179092

  18. Delayed hippocampal neuronal death in young gerbil following transient global cerebral ischemia is related to higher and longer-term expression of p63 in the ischemic hippocampus

    PubMed Central

    Bae, Eun Joo; Chen, Bai Hui; Yan, Bing Chun; Shin, Bich Na; Cho, Jeong Hwi; Kim, In Hye; Ahn, Ji Hyeon; Lee, Jae Chul; Tae, Hyun-Jin; Hong, Seongkweon; Kim, Dong Won; Cho, Jun Hwi; Lee, Yun Lyul; Won, Moo-Ho; Park, Joon Ha

    2015-01-01

    The tumor suppressor p63 is one of p53 family members and plays a vital role as a regulator of neuronal apoptosis in the development of the nervous system. However, the role of p63 in mature neuronal death has not been addressed yet. In this study, we first compared ischemia-induced effects on p63 expression in the hippocampal regions (CA1–3) between the young and adult gerbils subjected to 5 minutes of transient global cerebral ischemia. Neuronal death in the hippocampal CA1 region of young gerbils was significantly slow compared with that in the adult gerbils after transient global cerebral ischemia. p63 immunoreactivity in the hippocampal CA1 pyramidal neurons in the sham-operated young group was significantly low compared with that in the sham-operated adult group. p63 immunoreactivity was apparently changed in ischemic hippocampal CA1 pyramidal neurons in both ischemia-operated young and adult groups. In the ischemia-operated adult groups, p63 immunoreactivity in the hippocampal CA1 pyramidal neurons was significantly decreased at 4 days post-ischemia; however, p63 immunoreactivity in the ischemia-operated young group was significantly higher than that in the ischemia-operated adult group. At 7 days post-ischemia, p63 immunoreactivity was decreased in the hippocampal CA1 pyramidal neurons in both ischemia-operated young and adult groups. Change patterns of p63 level in the hippocampal CA1 region of adult and young gerbils after ischemic damage were similar to those observed in the immunohistochemical results. These findings indicate that higher and longer-term expression of p63 in the hippocampal CA1 region of the young gerbils after ischemia/reperfusion may be related to more delayed neuronal death compared to that in the adults. PMID:26199612

  19. Impairment of antioxidant defense via glutathione depletion sensitizes acute lymphoblastic leukemia cells for Smac mimetic-induced cell death.

    PubMed

    Schoeneberger, H; Belz, K; Schenk, B; Fulda, S

    2015-07-30

    Evasion of apoptosis in pediatric acute lymphoblastic leukemia (ALL) is linked to aberrant expression of inhibitor of apoptosis (IAP) proteins and dysregulated redox homeostasis, rendering leukemic cells vulnerable to redox-targeting therapies. Here we discover that inhibition of antioxidant defenses via glutathione (GSH) depletion by buthionine sulfoximine (BSO) primes ALL cells for apoptosis induced by the Smac mimetic BV6 that antagonizes IAP proteins. Similarly, BSO cooperates with BV6 to induce cell death in patient-derived primary leukemic samples, underscoring the clinical relevance. In contrast, BSO does not sensitize non-malignant lymphohematopoietic cells from healthy donors toward BV6, pointing to some tumor selectivity. Mechanistically, both agents cooperate to stimulate reactive oxygen species (ROS) production, which is required for BSO/BV6-induced cell death, as ROS inhibitors (that is, N-acetylcysteine, MnTBAP, Trolox) significantly rescue cell death. Further, BSO and BV6 cooperate to trigger lipid peroxidation, which is necessary for cell death, as genetic or pharmacological blockage of lipid peroxidation by GSH peroxidase 4 (GPX4) overexpression or α-tocopherol significantly inhibits BSO/BV6-mediated cell death. Consistently, GPX4 knockdown or GPX4 inhibitor RSL3 enhances lipid peroxidation and cell death by BSO/BV6 cotreatment. The discovery of redox regulation of Smac mimetic-induced cell death has important implications for developing rational Smac mimetic-based combination therapies. PMID:25381820

  20. 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

  1. A role for 4-hydroxynonenal, an aldehydic product of lipid peroxidation, in disruption of ion homeostasis and neuronal death induced by amyloid beta-peptide.

    PubMed

    Mark, R J; Lovell, M A; Markesbery, W R; Uchida, K; Mattson, M P

    1997-01-01

    Peroxidation of membrane lipids results in release of the aldehyde 4-hydroxynonenal (HNE), which is known to conjugate to specific amino acids of proteins and may alter their function. Because accumulating data indicate that free radicals mediate injury and death of neurons in Alzheimer's disease (AD) and because amyloid beta-peptide (A beta) can promote free radical production, we tested the hypothesis that HNE mediates A beta 25-35-induced disruption of neuronal ion homeostasis and cell death. A beta induced large increases in levels of free and protein-bound HNE in cultured hippocampal cells. HNE was neurotoxic in a time- and concentration-dependent manner, and this toxicity was specific in that other aldehydic lipid peroxidation products were not neurotoxic. HNE impaired Na+, K(+)-ATPase activity and induced an increase of neuronal intracellular free Ca2+ concentration. HNE increased neuronal vulnerability to glutamate toxicity, and HNE toxicity was partially attenuated by NMDA receptor antagonists, suggesting an excitotoxic component to HNE neurotoxicity. Glutathione, which was previously shown to play a key role in HNE metabolism in nonneuronal cells, attenuated the neurotoxicities of both A beta and HNE. The antioxidant propyl gallate protected neurons against A beta toxicity but was less effective in protecting against HNE toxicity. Collectively, the data suggest that HNE mediates A beta-induced oxidative damage to neuronal membrane proteins, which, in turn, leads to disruption of ion homeostasis and cell degeneration. PMID:8978733

  2. Intracellular acidification by inhibition of the Na+/H+-exchanger leads to caspase-independent death of cerebellar granule neurons resembling paraptosis.

    PubMed

    Schneider, D; Gerhardt, E; Bock, J; Müller, M M; Wolburg, H; Lang, F; Schulz, J B

    2004-07-01

    Potassium withdrawal is commonly used to induce caspase-mediated apoptosis in cerebellar granule neurons in vitro. However, the underlying and cell death-initiating mechanisms are unknown. We firstly investigated potassium efflux through the outward delayed rectifier K+ current (Ik) as a potential mediator. However, tetraethylammoniumchloride, an inhibitor of Ik, was ineffective to block apoptosis after potassium withdrawal. Since potassium withdrawal reduced intracellular pH (pHi) from 7.4 to 7.2, we secondly investigated the effects of intracellular acidosis. To study intracellular acidosis in cerebellar granule neurons, we inhibited the Na+/H+ exchanger (NHE) with 4-isopropyl-3-methylsulfonylbenzoyl-guanidine methanesulfonate (HOE 642) and 5-(N-ethyl-N-isopropyl)-amiloride. Both inhibitors concentration-dependently induced cell death and potentiated cell death after potassium withdrawal. Although inhibition of the NHE induced cell death with morphological criteria of apoptosis in light and electron microscopy including chromatin condensation, positive TUNEL staining and cell shrinkage, no internucleosomal DNA cleavage or activation of caspases was detected. In contrast to potassium withdrawal-induced apoptosis, cell death induced by intracellular acidification was not prevented by insulin-like growth factor-1, cyclo-adenosine-monophosphate, caspase inhibitors and transfection with an adenovirus expressing Bcl-XL. However, cycloheximide protected cerebellar granule neurons from death induced by potassium withdrawal as well as from death after treatment with HOE 642. Therefore, the molecular mechanisms leading to cell death after acidification appear to be different from the mechanisms after potassium withdrawal and resemble the biochemical but not the morphological characteristics of paraptosis. PMID:15017383

  3. Morphological characteristics of eosinophilic neuronal death after transient unilateral forebrain ischemia in Mongolian gerbils.

    PubMed

    Shen, Yanling; Wang, Zongli; Li, Fuying; Sun, Liyuan

    2016-06-01

    Various types of eosinophilic neurons (ENs) are found in the post-ischemic brain. The aim of the present study was to elucidate the temporal and spatial profile of ENs, the expression of TUNEL staining and ultrastructural characteristics in the core and peripheral regions of the cortex post-ischemia. Unilateral forebrain ischemia was induced in Mongolian gerbils by transient common carotid artery occlusions, and the brains from 3 h to 2 weeks post-ischemia were prepared for morphometric, electron microscopy (EM) and TUNEL staining of the ENs. Light microscopy showed that ENs with minimally abnormal nuclei and swollen cell bodies appeared at 3 h in the ischemic core and at 12 h in the periphery. Thereafter, ENs with pyknosis and irregular atrophic cytoplasm peaked at 12 h, pyknosis with scant cytoplasm peaked at 4 days, and TUNEL-positive staining was observed in the ischemic core. In the ischemic periphery, ENs had slightly atrophic cytoplasm and sequentially developed pyknosis, karyorrhexis and karyolysis over 1 week. These cells were also positive for TUNEL. In EM, severe organelle dilation and vacuolization preceded chromatin fragmentation in the ischemic core, while chromatin fragmentation and homogenization were the vital characteristics in the ischemic periphery. There might be two region-dependent pathways for EN changes in the post-ischemic brain: pyknosis with cytoplasmic shrinkage in the core and nuclear disintegration with slightly atrophic cytoplasm in the periphery. These pathways were comparable to necrosis and proceeded from non-classical apoptosis to necrosis, respectively. PMID:26607557

  4. Vitamin B-6 nutrition, 3-hydroxykynurenine (3HK), and neuronal cell death

    SciTech Connect

    Eastman, C.L.; Guilarte, T.R. )

    1990-02-26

    Neonatal vitamin B-6 restriction results in CNS neurochemical and neuropathological impairment including ataxia, tremor, and seizures. Coincident with the onset of neurological signs, there is a dramatic increase in the CNS levels of 3HK, an endogenous tryptophan metabolite which has been reported to possess convulsant and cytotoxic properties. Previous studies have shown that H{sub 2}O{sub 2} plays a critical role in 3HK toxicity. In 3HK exposed cell cultures, toxic levels of H{sub 2}O{sub 2} may be produced intracellularly by the action of cellular oxidases or on either side of the cell membrane by iron-catalyzed autooxidation of 3HK. Alternatively, H{sub 2}O{sub 2} may be required as a cosubstrate for the peroxidative oxidation of 3HK to a toxic quinoneimine. In order to address the issue of the site and mode of action of 3HK toxicity, the authors have examined the effects of treatments administered before and after exposure to 3HK such that their effects must reflect actions confined within the intracellular compartment. The results show that the toxicity of 3HK was attenuated by post-treatment with catalase and by pre-treatment with desferrioxamine or horseradish peroxidase. These results support a direct role for H{sub 2}O{sub 2} in 3HK toxicity and suggest that cell death results from toxic levels of H{sub 2}O{sub 2} in the intracellular compartment.

  5. Topiramate attenuates early brain injury following subarachnoid haemorrhage in rats via duplex protection against inflammation and neuronal cell death.

    PubMed

    Tian, Yong; Guo, Song-Xue; Li, Jian-Ru; Du, Hang-Gen; Wang, Chao-Hui; Zhang, Jian-Min; Wu, Qun

    2015-10-01

    Early brain injury (EBI) following aneurysmal subarachnoid haemorrhage (SAH) insults contributes to the poor prognosis and high mortality observed in SAH patients. Topiramate (TPM) is a novel, broad-spectrum, antiepileptic drug with a reported protective effect against several brain injuries. The current study aimed to investigate the potential of TPM for neuroprotection against EBI after SAH and the possible dose-dependency of this effect. An endovascular perforation SAH model was established in rats, and TPM was administered by intraperitoneal injection after surgery at three different doses (20mg/kg, 40mg/kg, and 80mg/kg). The animals' neurological scores and brain water content were evaluated, and ELISA, Western blotting and immunostaining assays were conducted to assess the effect of TPM. The results revealed that TPM lowers the elevated levels of myeloperoxidase and proinflammatory mediators observed after SAH in a dose-related fashion, and the nuclear factor-kappa B (NF-κB) signalling pathway is the target of neuroinflammation regulation. In addition, TPM ameliorated SAH-induced cortical neuronal apoptosis by influencing Bax, Bcl-2 and cleaved caspase-3 protein expression, and the effect of TPM was enhanced in a dose-dependent manner. Various dosages of TPM also upregulated the protein expression of the γ-aminobutyric acid (GABA)-ergic signalling molecules, GABAA receptor (GABAAR) α1, GABAAR γ2, and K(+)-Cl(-) co-transporter 2 (KCC2) together and downregulated Na(+)-K(+)-Cl(-) co-transporter 1 (NKCC1) expression. Thus, TPM may be an effective neuroprotectant in EBI after SAH by regulating neuroinflammation and neuronal cell death. PMID:26086367

  6. Protective Effect of Spermidine Against Excitotoxic Neuronal Death Induced by Quinolinic Acid in Rats: Possible Neurotransmitters and Neuroinflammatory Mechanism.

    PubMed

    Jamwal, Sumit; Singh, Shamsher; Kaur, Navneet; Kumar, Puneet

    2015-08-01

    Huntington disease is hyperkinetic movement disorder characterized by selective and immense degradation of GABAergic medium spiny neurons in striatum. Quinolinic acid (QA)-induced neurotoxicity involves a cascade of events such as excitotoxicity, ATP depletion, oxidative stress, neuroinflammation, as well as selective GABAergic neuronal loss. Therefore, we investigated spermidine, an endogenous molecule with free radical scavenging, anti-inflammatory, and N-methyl-D-aspartate receptor antagonistic properties, for its beneficial potential if any, in QA-induced Huntington's like symptoms in rats. Rats were administered with QA (200 nmol/2 µl saline) bilaterally on 0 day. Spermidine (5 and 10 mg/kg, p.o.) was administered for 21 days once a day. Behavioral parameters (body weight, locomotor activity, grip strength, and narrow beam walk) observations were done on 1st, 7th, 14th, and 21st day after QA treatment. On 21st day, animals were sacrificed and rat striatum was isolated for biochemical (LPO, GSH, Nitrite), neuroinflammation (TNF-α, IL-1β, and IL-6), and neurochemical analysis (GABA, glutamate, dopamine, norepinephrine, serotonin, DOPAC, HVA, 5-HIAA, adenosine, adenine, hypoxanthine, and inosine). QA treatment significantly altered body weight, locomotor activity, motor coordination, oxidative defense (increased LPO, nitrite, and decreased GSH), pro-inflammatory levels (TNF-α, IL-6 and IL-1β), GABA, glutamate, catecholamines level (norepinephrine, dopamine, and serotonin and their metabolites), and purines level (adenosine, inosine, and hypoxanthine). Spermidine (5 and 10 mg/kg, p.o.) significantly attenuated these alterations in body weight, motor impairments, oxidative stress, neuroinflammatory markers, GABA, glutamate, catecholamines, adenosine, and their metabolites levels in striatum. The neuroprotective effect of spermidine against QA-induced excitotoxic cell death is attributed to its antioxidant, N-methyl-D-aspartate receptor antagonistic, anti

  7. 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

  8. Validity of the GRACE (Global Registry of Acute Coronary Events) acute coronary syndrome prediction model for six month post‐discharge death in an independent data set

    PubMed Central

    Bradshaw, P J; Ko, D T; Newman, A M; Donovan, L R

    2006-01-01

    Objective To determine the validity of the GRACE (Global Registry of Acute Coronary Events) prediction model for death six months after discharge in all forms of acute coronary syndrome in an independent dataset of a community based cohort of patients with acute myocardial infarction (AMI). Design Independent validation study based on clinical data collected retrospectively for a clinical trial in a community based population and record linkage to administrative databases. Setting Study conducted among patients from the EFFECT (enhanced feedback for effective cardiac treatment) study from Ontario, Canada. Patients Randomly selected men and women hospitalised for AMI between 1999 and 2001. Main outcome measure Discriminatory capacity and calibration of the GRACE prediction model for death within six months of hospital discharge in the contemporaneous EFFECT AMI study population. Results Post‐discharge crude mortality at six months for the EFFECT study patients with AMI was 7.0%. The discriminatory capacity of the GRACE model was good overall (C statistic 0.80) and for patients with ST segment elevation AMI (STEMI) (0.81) and non‐STEMI (0.78). Observed and predicted deaths corresponded well in each stratum of risk at six months, although the risk was underestimated by up to 30% in the higher range of scores among patients with non‐STEMI. Conclusions In an independent validation the GRACE risk model had good discriminatory capacity for predicting post‐discharge death at six months and was generally well calibrated, suggesting that it is suitable for clinical use in general populations. PMID:16387810

  9. Hsp27 binding to the 3′UTR of bim mRNA prevents neuronal death during oxidative stress–induced injury: a novel cytoprotective mechanism

    PubMed Central

    Dávila, David; Jiménez-Mateos, Eva M.; Mooney, Claire M.; Velasco, Guillermo; Henshall, David C.; Prehn, Jochen H. M.

    2014-01-01

    Neurons face a changeable microenvironment and therefore need mechanisms that allow rapid switch on/off of their cytoprotective and apoptosis-inducing signaling pathways. Cellular mechanisms that control apoptosis activation include the regulation of pro/antiapoptotic mRNAs through their 3′-untranslated region (UTR). This region holds binding elements for RNA-binding proteins, which can control mRNA translation. Here we demonstrate that heat shock protein 27 (Hsp27) prevents oxidative stress–induced cell death in cerebellar granule neurons by specific regulation of the mRNA for the proapoptotic BH3-only protein, Bim. Hsp27 depletion induced by oxidative stress using hydrogen peroxide (H2O2) correlated with bim gene activation and subsequent neuronal death, whereas enhanced Hsp27 expression prevented these. This effect could not be explained by proteasomal degradation of Bim or bim promoter inhibition; however, it was associated with a specific increase in the levels of bim mRNA and with its binding to Hsp27. Finally, we determined that enhanced Hsp27 expression in neurons exposed to H2O2 or glutamate prevented the translation of a reporter plasmid where bim-3′UTR mRNA sequence was cloned downstream of a luciferase gene. These results suggest that repression of bim mRNA translation through binding to the 3′UTR constitutes a novel cytoprotective mechanism of Hsp27 during stress in neurons. PMID:25187648

  10. Mitochondrial ubiquitin ligase MITOL blocks S-nitrosylated MAP1B-light chain 1-mediated mitochondrial dysfunction and neuronal cell death

    PubMed Central

    Yonashiro, Ryo; Kimijima, Yuya; Shimura, Takuya; Kawaguchi, Kohei; Fukuda, Toshifumi; Inatome, Ryoko; Yanagi, Shigeru

    2012-01-01

    Nitric oxide (NO) is implicated in neuronal cell survival. However, excessive NO production mediates neuronal cell death, in part via mitochondrial dysfunction. Here, we report that the mitochondrial ubiquitin ligase, MITOL, protects neuronal cells from mitochondrial damage caused by accumulation of S-nitrosylated microtubule-associated protein 1B-light chain 1 (LC1). S-nitrosylation of LC1 induces a conformational change that serves both to activate LC1 and to promote its ubiquination by MITOL, indicating that microtubule stabilization by LC1 is regulated through its interaction with MITOL. Excessive NO production can inhibit MITOL, and MITOL inhibition resulted in accumulation of S-nitrosylated LC1 following stimulation of NO production by calcimycin and N-methyl-D-aspartate. LC1 accumulation under these conditions resulted in mitochondrial dysfunction and neuronal cell death. Thus, the balance between LC1 activation by S-nitrosylation and down-regulation by MITOL is critical for neuronal cell survival. Our findings may contribute significantly to an understanding of the mechanisms of neurological diseases caused by nitrosative stress-mediated mitochondrial dysfunction. PMID:22308378

  11. 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

  12. Methylglyoxal produced by amyloid-β peptide-induced nitrotyrosination of triosephosphate isomerase triggers neuronal death in Alzheimer's disease.

    PubMed

    Tajes, Marta; Eraso-Pichot, Abel; Rubio-Moscardó, Fanny; Guivernau, Biuse; Ramos-Fernández, Eva; Bosch-Morató, Mònica; Guix, Francesc Xavier; Clarimón, Jordi; Miscione, Gian Pietro; Boada, Mercé; Gil-Gómez, Gabriel; Suzuki, Toshiharu; Molina, Henrik; Villà-Freixa, Jordi; Vicente, Rubén; Muñoz, Francisco J

    2014-01-01

    Amyloid-β peptide (Aβ) aggregates induce nitro-oxidative stress, contributing to the characteristic neurodegeneration found in Alzheimer's disease (AD). One of the most strongly nitrotyrosinated proteins in AD is the triosephosphate isomerase (TPI) enzyme which regulates glycolytic flow, and its efficiency decreased when it is nitrotyrosinated. The main aims of this study were to analyze the impact of TPI nitrotyrosination on cell viability and to identify the mechanism behind this effect. In human neuroblastoma cells (SH-SY5Y), we evaluated the effects of Aβ42 oligomers on TPI nitrotyrosination. We found an increased production of methylglyoxal (MG), a toxic byproduct of the inefficient nitro-TPI function. The proapoptotic effects of Aβ42 oligomers, such as decreasing the protective Bcl2 and increasing the proapoptotic caspase-3 and Bax, were prevented with a MG chelator. Moreover, we used a double mutant TPI (Y165F and Y209F) to mimic nitrosative modifications due to Aβ action. Neuroblastoma cells transfected with the double mutant TPI consistently triggered MG production and a decrease in cell viability due to apoptotic mechanisms. Our data show for the first time that MG is playing a key role in the neuronal death induced by Aβ oligomers. This occurs because of TPI nitrotyrosination, which affects both tyrosines associated with the catalytic center. PMID:24614897

  13. Crosstalk between 2 organelles: Lysosomal storage of heparan sulfate causes mitochondrial defects and neuronal death in mucopolysaccharidosis III type C

    PubMed Central

    Pshezhetsky, Alexey V

    2015-01-01

    More than 30% of all lysosomal diseases are mucopolysaccharidoses, disorders affecting the enzymes needed for the stepwise degradation of glycosaminoglycans (mucopolysaccharides). Mucopolysaccharidosis type IIIC (MPS IIIC) is a severe neurologic disease caused by genetic deficiency of heparan sulfate acetyl-CoA: α-glucosaminide N-acetyltransferase (HGSNAT). Through our studies, we have cloned the gene, identified molecular defects in MPS IIIC patients and most recently completed phenotypic characterization of the first animal model of the disease, a mouse with a germline inactivation of the Hgsnat gene.1 The obtained data have led us to propose that Hgsnat deficiency and lysosomal accumulation of heparan sulfate in microglial cells followed by their activation and cytokine release result in mitochondrial dysfunction in the neurons causing their death which explains why MPS IIIC manifests primarily as a neurodegenerative disease. The goal of this addendum is to summarize data yielding new insights into the mechanism of MPS IIIC and promising novel therapeutic solutions for this and similar disorders. PMID:26459666

  14. Deletion of a single allele of the Pex11β gene is sufficient to cause oxidative stress, delayed differentiation and neuronal death in mouse brain

    PubMed Central

    Ahlemeyer, Barbara; Gottwald, Magdalena; Baumgart-Vogt, Eveline

    2012-01-01

    SUMMARY Impaired neuronal migration and cell death are commonly observed in patients with peroxisomal biogenesis disorders (PBDs), and in mouse models of this diseases. In Pex11β-deficient mice, we observed that the deletion of a single allele of the Pex11β gene (Pex11β+/− heterozygous mice) caused cell death in primary neuronal cultures prepared from the neocortex and cerebellum, although to a lesser extent as compared with the homozygous-null animals (Pex11β−/− mice). In corresponding brain sections, cell death was rare, but differences between the genotypes were similar to those found in vitro. Because PEX11β has been implicated in peroxisomal proliferation, we searched for alterations in peroxisomal abundance in the brain of heterozygous and homozygous Pex11β-null mice compared with wild-type animals. Deletion of one allele of the Pex11β gene slightly increased the abundance of peroxisomes, whereas the deletion of both alleles caused a 30% reduction in peroxisome number. The size of the peroxisomal compartment did not correlate with neuronal death. Similar to cell death, neuronal development was delayed in Pex11β+/− mice, and to a further extent in Pex11β−/− mice, as measured by a reduced mRNA and protein level of synaptophysin and a reduced protein level of the mature isoform of MAP2. Moreover, a gradual increase in oxidative stress was found in brain sections and primary neuronal cultures from wild-type to heterozygous to homozygous Pex11β-deficient mice. SOD2 was upregulated in neurons from Pex11β+/− mice, but not from Pex11β−/− animals, whereas the level of catalase remained unchanged in neurons from Pex11β+/− mice and was reduced in those from Pex11β−/− mice, suggesting a partial compensation of oxidative stress in the heterozygotes, but a failure thereof in the homozygous Pex11β−/− brain. In conclusion, we report the alterations in the brain caused by the deletion of a single allele of the Pex11β gene. Our data

  15. Identification of a novel synergistic induction of cell death by Smac mimetic and HDAC inhibitors in acute myeloid leukemia cells.

    PubMed

    Steinwascher, Sofie; Nugues, Anne-Lucie; Schoeneberger, Hannah; Fulda, Simone

    2015-09-28

    Inhibitor of Apoptosis (IAP) proteins are expressed at high levels in acute myeloid leukemia (AML) and contribute to resistance to programmed cell death. Here, we report that inhibition of IAP proteins by the small-molecule Smac mimetic BV6 acts together with histone deacetylase (HDAC) inhibitors (HDACIs) such as MS275 or SAHA to trigger cell death in AML cell lines in a synergistic manner, as underscored by calculation of combination index (CI). Also, BV6 and HDACIs cooperate to trigger DNA fragmentation, a marker of apoptotic cell death, and to suppress long-term clonogenic survival of AML cells. In contrast, equimolar concentrations of BV6 and MS275 or SAHA do not synergize to elicit cell death in normal peripheral blood lymphocytes (PBLs), emphasizing some tumor cell selectivity of this combination treatment. Addition of the tumor necrosis factor (TNF)α-blocking antibody Enbrel significantly reduces BV6/MS275-induced cell death in the majority of AML cell lines, indicating that autocrine/paracrine TNFα signaling contributes to cell death. Remarkably, the broad-range caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (zVAD.fmk) fails to rescue MV4-11, Molm13 and OCI-AML3 cells and even enhances BV6/MS275-mediated cell death, whereas zVAD.fmk reduces BV6/MS275-induced cell death in NB4 cells. Annexin-V/propidium iodide (PI) double staining reveals that BV6/MS275 cotreatment predominately increases the percentage of double-positive cells. Of note, the Receptor-Interacting Protein (RIP)1 inhibitor necrostatin-1 (Nec-1) or the Mixed Lineage Kinase Domain-Like protein (MLKL) inhibitor necrosulfonamide (NSA) significantly reduce BV6/MS275-induced cell death in the presence of zVAD.fmk, suggesting that BV6/MS275 cotreatment triggers necroptosis when caspases are inhibited. Thus, BV6 acts in concert with HDACIs to induce cell death in AML cells and can bypass apoptosis resistance, at least in several AML cell lines, by engaging necroptosis as an

  16. Is a good death possible in Australian critical and acute settings?: physician experiences with end-of-life care

    PubMed Central

    2014-01-01

    Background In Australia approximately 70% of all deaths are institutionalised but over 15% of deaths occur in intensive care settings where the ability to provide a “good death” is particularly inhibited. Yet, there is a growing trend for death and dying to be managed in the ICU and physicians are increasingly challenged to meet the new expectations of their specialty. This study examined the unexplored interface between specialised Australian palliative and intensive care and the factors influencing a physician’s ability to manage deaths well. Method A qualitative investigation was focused on palliative and critical/acute settings. A thematic analysis was conducted on semi-structured in-depth interviews with 13 specialist physicians. Attention was given to eliciting meanings and experiences in Australian end-of-life care. Results Physicians negotiated multiple influences when managing dying patients and their families in the ICU. The way they understood and experienced end-of-life care practices was affected by cultural, institutional and professional considerations, and personal values and beliefs. Interpersonal and intrapsychic aspects highlighted the emotional and psychological relationship physicians have with patients and others. Many physicians were also unaware of what their cross-disciplinary colleagues could or could not do; poor professional recognition and collaboration, and ineffective care goal transition impaired their ability to assist good deaths. Experience was subject to the efficacy of physicians in negotiating complex bedside dynamics. Conclusions Regardless of specialty, all physicians identified the problematic nature of providing expert palliation in critical and acute settings. Strategies for integrating specialised palliative and intensive care were offered with corresponding directions for future research and clinical development. PMID:25147481

  17. 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

  18. Pro-inflammatory cytokines derived from West Nile virus (WNV)-infected SK-N-SH cells mediate neuroinflammatory markers and neuronal death

    PubMed Central

    2010-01-01

    Background WNV-associated encephalitis (WNVE) is characterized by increased production of pro-inflammatory mediators, glial cells activation and eventual loss of neurons. WNV infection of neurons is rapidly progressive and destructive whereas infection of non-neuronal brain cells is limited. However, the role of neurons and pathological consequences of pro-inflammatory cytokines released as a result of WNV infection is unclear. Therefore, the objective of this study was to examine the role of key cytokines secreted by WNV-infected neurons in mediating neuroinflammatory markers and neuronal death. Methods A transformed human neuroblastoma cell line, SK-N-SH, was infected with WNV at multiplicity of infection (MOI)-1 and -5, and WNV replication kinetics and expression profile of key pro-inflammatory cytokines were analyzed by plaque assay, qRT-PCR, and ELISA. Cell death was measured in SK-N-SH cell line in the presence and absence of neutralizing antibodies against key pro-inflammatory cytokines using cell viability assay, TUNEL and flow cytometry. Further, naïve primary astrocytes were treated with UV-inactivated supernatant from mock- and WNV-infected SK-N-SH cell line and the activation of astrocytes was measured using flow cytometry and ELISA. Results WNV-infected SK-N-SH cells induced the expression of IL-1β, -6, -8, and TNF-α in a dose- and time-dependent manner, which coincided with increase in virus-induced cell death. Treatment of cells with anti-IL-1β or -TNF-α resulted in significant reduction of the neurotoxic effects of WNV. Furthermore treatment of naïve astrocytes with UV-inactivated supernatant from WNV-infected SK-N-SH cell line increased expression of glial fibrillary acidic protein and key inflammatory cytokines. Conclusion Our results for the first time suggest that neurons are one of the potential sources of pro-inflammatory cytokines in WNV-infected brain and these neuron-derived cytokines contribute to WNV-induced neurotoxicity. Moreover

  19. The novel marker LTBP2 predicts all-cause and pulmonary death in patients with acute dyspnoea.

    PubMed

    Breidthardt, Tobias; Vanpoucke, Griet; Potocki, Mihael; Mosimann, Tamina; Ziller, Ronny; Thomas, Gregoire; Laroy, Wouter; Moerman, Piet; Socrates, Thenral; Drexler, Beatrice; Mebazaa, Alexandre; Kas, Koen; Mueller, Christian

    2012-11-01

    The risk stratification in patients presenting with acute dyspnoea remains a challenge. We therefore conducted a prospective, observational cohort study enrolling 292 patients presenting to the emergency department with acute dyspnoea. A proteomic approach for antibody-free targeted protein quantification based on high-end MS was used to measure LTBP2 [latent TGF (transforming growth factor)-binding protein 2] levels. Final diagnosis and death during follow-up were adjudicated blinded to LTBP2 levels. AHF (acute heart failure) was the final diagnosis in 54% of patients. In both AHF (P<0.001) and non-AHF (P=0.015) patients, LTBP2 levels at presentation were significantly higher in non-survivors compared with survivors with differences on median levels being 2.2- and 1.5-fold respectively. When assessing the cause of death, LTBP2 levels were significantly higher in patients dying from pulmonary causes (P=0.0005). Overall, LTBP2 powerfully predicted early pulmonary death {AUC (area under the curve), 0.95 [95% CI (confidence interval), 0.91-0.98]}. In ROC (receiver operating characteristic) curve analyses for the prediction of 1-year mortality LTBP2 achieved an AUC of 0.77 (95% CI, 0.71-0.84); comparable with the predictive potential of NT-proBNP [N-terminal pro-B-type natriuruetic peptide; 0.77 (95% CI, 0.72-0.82)]. Importantly, the predictive potential of LTBP2 persisted in patients with AHF as the cause of dypnea (AUC 0.78) and was independent of renal dysfunction (AUC 0.77). In a multivariate Cox regression analysis, LTBP2 was the strongest independent predictor of death [HR (hazard ratio), 3.76 (95% CI, 2.13-6.64); P<0.0001]. In conclusion, plasma levels of LTBP2 present a novel and powerful predictor of all-cause mortality, and particularly pulmonary death. Cause-specific prediction of death would enable targeted prevention, e.g. with pre-emptive antibiotic therapy. PMID:22587491

  20. REST alleviates neurotoxic prion peptide-induced synaptic abnormalities, neurofibrillary degeneration and neuronal death partially via LRP6-mediated Wnt-β-catenin signaling

    PubMed Central

    Song, Zhiqi; Zhu, Ting; Zhou, Xiangmei; Barrow, Paul; Yang, Wei; Cui, Yongyong; Yang, Lifeng; Zhao, Deming

    2016-01-01

    Prion diseases are a group of infectious neurodegenerative diseases characterized by multiple neuropathological hallmarks including synaptic damage, spongiform degeneration and neuronal death. The factors and mechanisms that maintain cellular morphological integrity and protect against neurodegeneration in prion diseases are still unclear. Here we report that after stimulation with the neurotoxic PrP106-126 fragment in primary cortical neurons, REST translocates from the cytoplasm to the nucleus and protects neurons from harmful effects of PrP106-126. Overexpression of REST reduces pathological damage and abnormal biochemical alterations of neurons induced by PrP106-126 and maintains neuronal viability by stabilizing the level of pro-survival protein FOXO1 and inhibiting the permeability of the mitochondrial outer membrane, release of cytochrome c from mitochondria to cytoplasm and the activation of Capase3. Conversely, knockdown of REST exacerbates morphological damage and inhibits the expression of FOXO1. Additionally, by overexpression or knockdown of LRP6, we further show that LRP6-mediated Wnt-β-catenin signaling partly regulates the expression of REST. Collectively, we demonstrate for the first time novel neuroprotective function of REST in prion diseases and hypothesise that the LRP6-Wnt-β-catenin/REST signaling plays critical and collaborative roles in neuroprotection. This signaling of neuronal survival regulation could be explored as a viable therapeutic target for prion diseases and associated neurodegenerative diseases. PMID:26919115

  1. 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

  2. Effect of tolbutamide, glyburide and glipizide administered supraspinally on CA3 hippocampal neuronal cell death and hyperglycemia induced by kainic acid in mice.

    PubMed

    Kim, Chea-Ha; Park, Soo-Hyun; Sim, Yun-Beom; Kim, Sung-Su; Kim, Su-Jin; Lim, Su-Min; Jung, Jun-Sub; Suh, Hong-Won

    2014-05-20

    Sulfonylureas are widely used oral drugs for the treatment of type II diabetes mellitus. In the present study, the effects of sulfonylureas administered supraspinally on kainic acid (KA)-induced hippocampal neuronal cell death and hyperglycemia were studied in ICR mice. Mice were pretreated intracerebroventricularly (i.c.v.) with 30μg of tolbutamide, glyburide or glipizide for 10min and then, mice were administered i.c.v. with KA (0.1μg). The neuronal cell death in the CA3 region in the hippocampus was assessed 24h after KA administration and the blood glucose level was measured 30, 60, and 120min after KA administration. We found that i.c.v. pretreatment with tolbutamide, glyburide or glipizide attenuated the KA-induced neuronal cell death in CA3 region of the hippocampus and hyperglycemia. In addition, KA administered i.c.v. caused an elevation of plasma corticosterone level and a reduction of the plasma insulin level. The i.c.v. pretreatment with tolbutamide, glyburide or glipizide attenuated KA-induced increase of plasma corticosterone level. Furthermore, i.c.v. pretreatment with tolbutamide, glyburide or glipizide causes an elevation of plasma insulin level. Glipizide, but not tolbutamide or glyburide, pretreated i.c.v. caused a reversal of KA-induced hypoinsulinemic effect. Our results suggest that supraspinally administered tolbutamide, glyburide and glipizide exert a protective effect against KA-induced neuronal cells death in CA3 region of the hippocampus. The neuroprotective effect of tolbutamide, glyburide and glipizide appears to be mediated by lowering the blood glucose level induced by KA. PMID:24713348

  3. Overexpression of hsp27 Rescued Neuronal Cell Death and Reduction in Life- and Health-Span in Drosophila melanogaster Against Prolonged Exposure to Dichlorvos.

    PubMed

    Pandey, Ashutosh; Saini, Sanjay; Khatoon, Rehana; Sharma, Divya; Narayan, Gopeshwar; Kar Chowdhuri, Debapratim

    2016-07-01

    Long-term exposure to dichlorvos (O,O-dimethyl-2,2-dichlorovinyl phosphate (DDVP), an organophosphate pesticide) is reported to exert neurotoxicity, i.e., generation of reactive oxygen species (ROS), oxidative damage, and neuronal cell death along with life- and health-span reduction in nontarget organisms including humans. However, studies on genetic modulation towards neuroprotection against prolonged DDVP exposure are elusive. Hsp27 (a small heat shock protein) is involved in various cellular processes and thus has attained emphasis as a therapeutic target. We aimed to examine the protective effect of hsp27 overexpression against prolonged DDVP exposure using an in vivo model Drosophila melanogaster. Flies were exposed to 15.0 ng/ml DDVP for a prolonged period to examine neuronal cell death, locomotor performance, and lifespan. After prolonged exposure, cell death, ROS level, glutathione depletion, nicotinamide adenine dinucleotide phosphate level (NADPH), glucose-6-phosphate dehydrogenase (G6PD), and thioredoxin reductase (TrxR) activities were examined in fly brain tissues at different days of age (days 10, 20, and 30). Flies with ubiquitous overexpression of hsp27 showed better resistance (improved lifespan and locomotor performance) in comparison to that targeted to motor neurons and nervous system. These flies also exhibited lesser intracellular ROS level and glutathione depletion by restoring G6PD activity, NADPH level, and TrxR activity in their brains thereby resisted neuronal cell death. Conversely, hsp27 knockdown flies exhibited reversal of the above endpoints. The study evidenced the neuroprotective efficacy of hsp27 overexpression against prolonged DDVP exposure and favored Hsp27 as a therapeutic target towards achieving better organismal (including human) health against long-term chemical exposure. PMID:26033218

  4. Lack of Neurotrophin-3 Results in Death of Spinal Sensory Neurons and Premature Differentiation of Their Precursors

    PubMed Central

    Fariñas, Isabel; Yoshida, Cathleen K.; Backus, Carey; Reichardt, Louis F.

    2009-01-01

    Summary To understand mechanisms resulting in the absence of two-thirds of spinal sensory neurons in mice lacking NT-3, we have compared dorsal root ganglia development in normal and mutant embryos. The reduction in neurons, achieved by E13, results from several deficits: first, elevated neuronal apoptosis significantly reduces neuronal numbers; second, elevated neurogenesis between E11 and E12, without changes in rates of precursor proliferation or apoptosis, depletes the precursor pool; consequently, the reduced precursor pool prevents increases in neuronal numbers between E12 and E13, when most neurons are born in normal animals. Although deficits occur before final target innervation, we show that NT-3 is expressed at all stages in regions accessible to these neurons or their axons and is only restricted to final targets after innervation. PMID:8982156

  5. 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

  6. Protection of hypoglycemia-induced neuronal death by β-hydroxybutyrate involves the preservation of energy levels and decreased production of reactive oxygen species.

    PubMed

    Julio-Amilpas, Alberto; Montiel, Teresa; Soto-Tinoco, Eva; Gerónimo-Olvera, Cristian; Massieu, Lourdes

    2015-05-01

    Glucose is the main energy substrate in brain but in certain circumstances such as prolonged fasting and the suckling period alternative substrates can be used such as the ketone bodies (KB), beta-hydroxybutyrate (BHB), and acetoacetate. It has been shown that KB prevent neuronal death induced during energy limiting conditions and excitotoxicity. The protective effect of KB has been mainly attributed to the improvement of mitochondrial function. In the present study, we have investigated the protective effect of D-BHB against neuronal death induced by severe noncoma hypoglycemia in the rat in vivo and by glucose deprivation (GD) in cortical cultures. Results show that systemic administration of D-BHB reduces reactive oxygen species (ROS) production in distinct cortical areas and subregions of the hippocampus and efficiently prevents neuronal death in the cortex of hypoglycemic animals. In vitro results show that D-BHB stimulates ATP production and reduces ROS levels, while the nonphysiologic isomer of BHB, L-BHB, has no effect on energy production but reduces ROS levels. Data suggest that protection by BHB, not only results from its metabolic action but is also related to its capability to reduce ROS, rendering this KB as a suitable candidate for the treatment of ischemic and traumatic injury. PMID:25649993

  7. Protection of hypoglycemia-induced neuronal death by β-hydroxybutyrate involves the preservation of energy levels and decreased production of reactive oxygen species

    PubMed Central

    Julio-Amilpas, Alberto; Montiel, Teresa; Soto-Tinoco, Eva; Gerónimo-Olvera, Cristian; Massieu, Lourdes

    2015-01-01

    Glucose is the main energy substrate in brain but in certain circumstances such as prolonged fasting and the suckling period alternative substrates can be used such as the ketone bodies (KB), beta-hydroxybutyrate (BHB), and acetoacetate. It has been shown that KB prevent neuronal death induced during energy limiting conditions and excitotoxicity. The protective effect of KB has been mainly attributed to the improvement of mitochondrial function. In the present study, we have investigated the protective effect of D-BHB against neuronal death induced by severe noncoma hypoglycemia in the rat in vivo and by glucose deprivation (GD) in cortical cultures. Results show that systemic administration of D-BHB reduces reactive oxygen species (ROS) production in distinct cortical areas and subregions of the hippocampus and efficiently prevents neuronal death in the cortex of hypoglycemic animals. In vitro results show that D-BHB stimulates ATP production and reduces ROS levels, while the nonphysiologic isomer of BHB, L-BHB, has no effect on energy production but reduces ROS levels. Data suggest that protection by BHB, not only results from its metabolic action but is also related to its capability to reduce ROS, rendering this KB as a suitable candidate for the treatment of ischemic and traumatic injury. PMID:25649993

  8. Cotreatment with Smac mimetics and demethylating agents induces both apoptotic and necroptotic cell death pathways in acute lymphoblastic leukemia cells.

    PubMed

    Gerges, Steve; Rohde, Katharina; Fulda, Simone

    2016-05-28

    Treatment resistance in acute lymphoblastic leukemia (ALL) is often caused by defects in programmed cell death, e.g. by overexpression of Inhibitor of Apoptosis (IAP) proteins. Here, we report that small-molecule Smac mimetics (i.e. BV6, LCL161, birinapant) that neutralize x-linked IAP (XIAP), cellular IAP (cIAP)1 and cIAP2 cooperate with demethylating agents (i.e. 5-azacytidine (5AC) or 5-aza-2'-deoxycytidine (DAC)) to induce cell death in ALL cells. Molecular studies reveal that induction of cell death is preceded by BV6-mediated depletion of cIAP1 protein and involves tumor necrosis factor (TNF)α autocrine/paracrine signaling, since the TNFα-blocking antibody Enbrel significantly reduces BV6/5AC-induced cell death. While BV6/5AC cotreatment induces caspase-3 activation, the broad-range caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (zVAD.fmk) only partly rescues ALL cells from BV6/5AC-induced cell death. This indicates that BV6/5AC cotreatment engages non-apoptotic cell death upon caspase inhibition. Indeed, genetic silencing of key components of necroptosis such as Receptor-Interacting Protein (RIP)3 or mixed lineage kinase domain-like (MLKL) in parallel with administration of zVAD.fmk provides a significantly better protection against BV6/5AC-induced cell death compared to the use of zVAD.fmk alone. Similarly, concomitant administration of pharmacological inhibitors of necroptosis (i.e. necrostatin-1s, GSK'872, dabrafenib, NSA) together with zVAD.fmk is superior in rescuing cells from BV6/5AC-induced cell death compared to the use of zVAD.fmk alone. These findings demonstrate that in ALL cells BV6/5AC-induced cell death is mediated via both apoptotic and necroptotic pathways. Importantly, BV6/5AC cotreatment triggers necroptosis in ALL cells that are resistant to apoptosis due to caspase inhibition. This opens new perspectives to overcome apoptosis resistance with important implications for the development of new treatment strategies

  9. Enhancing mitochondrial calcium buffering capacity reduces aggregation of misfolded SOD1 and motor neuron cell death without extending survival in mouse models of inherited amyotrophic lateral sclerosis.

    PubMed

    Parone, Philippe A; Da Cruz, Sandrine; Han, Joo Seok; McAlonis-Downes, Melissa; Vetto, Anne P; Lee, Sandra K; Tseng, Eva; Cleveland, Don W

    2013-03-13

    Mitochondria have been proposed as targets for toxicity in amyotrophic lateral sclerosis (ALS), a progressive, fatal adult-onset neurodegenerative disorder characterized by the selective loss of motor neurons. A decrease in the capacity of spinal cord mitochondria to buffer calcium (Ca(2+)) has been observed in mice expressing ALS-linked mutants of SOD1 that develop motor neuron disease with many of the key pathological hallmarks seen in ALS patients. In mice expressing three different ALS-causing SOD1 mutants, we now test the contribution of the loss of mitochondrial Ca(2+)-buffering capacity to disease mechanism(s) by eliminating ubiquitous expression of cyclophilin D, a critical regulator of Ca(2+)-mediated opening of the mitochondrial permeability transition pore that determines mitochondrial Ca(2+) content. A chronic increase in mitochondrial buffering of Ca(2+) in the absence of cyclophilin D was maintained throughout disease course and was associated with improved mitochondrial ATP synthesis, reduced mitochondrial swelling, and retention of normal morphology. This was accompanied by an attenuation of glial activation, reduction in levels of misfolded SOD1 aggregates in the spinal cord, and a significant suppression of motor neuron death throughout disease. Despite this, muscle denervation, motor axon degeneration, and disease progression and survival were unaffected, thereby eliminating mutant SOD1-mediated loss of mitochondrial Ca(2+) buffering capacity, altered mitochondrial morphology, motor neuron death, and misfolded SOD1 aggregates, as primary contributors to disease mechanism for fatal paralysis in these models of familial ALS. PMID:23486940

  10. Early and treatment-related deaths in childhood acute myeloid leukaemia in the Nordic countries: 1984-2003.

    PubMed

    Molgaard-Hansen, Lene; Möttönen, Merja; Glosli, Heidi; Jónmundsson, Guðmundur K; Abrahamsson, Jonas; Hasle, Henrik

    2010-12-01

    Despite major improvements in the cure rate of childhood acute myeloid leukaemia (AML), 5-15% of patients still die from treatment-related complications. In a historical prospective cohort study, we analysed the frequency, clinical features and risk factors for early deaths (ED) and treatment-related deaths (TRD) in 525 children included in the Nordic Society of Paediatric Haematology and Oncology (NOPHO)-AML-84, -88 and -93 trials. Seventy patients (13%) died before starting treatment or from treatment-related complications. The death rate rose from 11% in NOPHO-AML-84 to 29% in -88, but then fell to 8% in -93. Sixteen patients (3%) died within the first 2 weeks, mainly from bleeding or leucostasis. Hyperleucocytosis, age <2 or ≥10 years were risk factors. After day 15, 10% of patients died from treatment-related complications with infection as the main cause of death. Risk factors were age <2 or ≥10 years and treatment according to the NOPHO-AML-88 protocol. The number of EDs and TRDs in AML is high. Therefore optimal antifungal prophylaxis is essential, and studies on the benefit of antibacterial prophylaxis and individual risk factors for ED and TRD are needed. PMID:20955398

  11. A Case of Mushroom Poisoning with Russula subnigricans: Development of Rhabdomyolysis, Acute Kidney Injury, Cardiogenic Shock, and Death.

    PubMed

    Cho, Jong Tae; Han, Jin Hyung

    2016-07-01

    Mushroom exposures are increasing worldwide. The incidence and fatality of mushroom poisoning are reported to be increasing. Several new syndromes in mushroom poisoning have been described. Rhabdomyolytic mushroom poisoning is one of new syndromes. Russula subnigricans mushroom can cause delayed-onset rhabdomyolysis with acute kidney injury in the severely poisoned patient. There are few reports on the toxicity of R. subnigricans. This report represents the first record of R. subnigricans poisoning with rhabdomyolysis in Korea, describing a 51-year-old man who suffered from rhabdomyolysis, acute kidney injury, severe hypocalcemia, respiratory failure, ventricular tachycardia, cardiogenic shock, and death. Mushroom poisoning should be considered in the evaluation of rhabdomyolysis of unknown cause. Furthermore, R. subnigricans should be considered in the mushroom poisoning with rhabdomyolysis. PMID:27366018

  12. A Case of Mushroom Poisoning with Russula subnigricans: Development of Rhabdomyolysis, Acute Kidney Injury, Cardiogenic Shock, and Death

    PubMed Central

    2016-01-01

    Mushroom exposures are increasing worldwide. The incidence and fatality of mushroom poisoning are reported to be increasing. Several new syndromes in mushroom poisoning have been described. Rhabdomyolytic mushroom poisoning is one of new syndromes. Russula subnigricans mushroom can cause delayed-onset rhabdomyolysis with acute kidney injury in the severely poisoned patient. There are few reports on the toxicity of R. subnigricans. This report represents the first record of R. subnigricans poisoning with rhabdomyolysis in Korea, describing a 51-year-old man who suffered from rhabdomyolysis, acute kidney injury, severe hypocalcemia, respiratory failure, ventricular tachycardia, cardiogenic shock, and death. Mushroom poisoning should be considered in the evaluation of rhabdomyolysis of unknown cause. Furthermore, R. subnigricans should be considered in the mushroom poisoning with rhabdomyolysis. PMID:27366018

  13. Quinazoline-based tricyclic compounds that regulate programmed cell death, induce neuronal differentiation, and are curative in animal models for excitotoxicity and hereditary brain disease

    PubMed Central

    Vainshtein, A; Veenman, L; Shterenberg, A; Singh, S; Masarwa, A; Dutta, B; Island, B; Tsoglin, E; Levin, E; Leschiner, S; Maniv, I; Pe’er, L; Otradnov, I; Zubedat, S; Aga-Mizrachi, S; Weizman, A; Avital, A; Marek, I; Gavish, M

    2015-01-01

    Expanding on a quinazoline scaffold, we developed tricyclic compounds with biological activity. These compounds bind to the 18 kDa translocator protein (TSPO) and protect U118MG (glioblastoma cell line of glial origin) cells from glutamate-induced cell death. Fascinating, they can induce neuronal differentiation of PC12 cells (cell line of pheochromocytoma origin with neuronal characteristics) known to display neuronal characteristics, including outgrowth of neurites, tubulin expression, and NeuN (antigen known as ‘neuronal nuclei’, also known as Rbfox3) expression. As part of the neurodifferentiation process, they can amplify cell death induced by glutamate. Interestingly, the compound 2-phenylquinazolin-4-yl dimethylcarbamate (MGV-1) can induce expansive neurite sprouting on its own and also in synergy with nerve growth factor and with glutamate. Glycine is not required, indicating that N-methyl-D-aspartate receptors are not involved in this activity. These diverse effects on cells of glial origin and on cells with neuronal characteristics induced in culture by this one compound, MGV-1, as reported in this article, mimic the diverse events that take place during embryonic development of the brain (maintenance of glial integrity, differentiation of progenitor cells to mature neurons, and weeding out of non-differentiating progenitor cells). Such mechanisms are also important for protective, curative, and restorative processes that occur during and after brain injury and brain disease. Indeed, we found in a rat model of systemic kainic acid injection that MGV-1 can prevent seizures, counteract the process of ongoing brain damage, including edema, and restore behavior defects to normal patterns. Furthermore, in the R6-2 (transgenic mouse model for Huntington disease; Strain name: B6CBA-Tg(HDexon1)62Gpb/3J) transgenic mouse model for Huntington disease, derivatives of MGV-1 can increase lifespan by >20% and reduce incidence of abnormal movements. Also in vitro

  14. Radiation injury and acute death in Armadillidium vulgare (terrestrial isopod, Crustacea) subjected to ionizing radiation. [/sup 137/Cs

    SciTech Connect

    Nakatsuchi, Y.; Egami, N.

    1981-01-01

    From whole- and partial-body irradiation experiments with adult Armadillidium vulgare, the following conclusions were drawn: the LD/sub 50/-30 days for this animal when subjected to ..gamma.. radiation at 25 +- 2/sup 0/C was about 30 kR. Radiosensitivity of the animal changed during the molt cycle. Ionizing radiation increased mortality at ecdysis and during intermolt stages. Anatomical and histological observations indicated that (1) gastrointestinal injury as the major cause of acute death does not apply to this animal because the intestine is not a cell-proliferative organ: (2) the epidermis may be the critical target organ.

  15. [On the importance of a comprehensive study for diagnostics of death from acute ethanol poisoning and coronary heart disease].

    PubMed

    Porodenko, V A; Korkhmazov, V T

    2011-01-01

    Over 30 000 cases of acute poisoning with ethyl alcohol and its surrogates are recorded annually in this country. Differential diagnostics between fatal poisoning and death from coronary heart disease encounters serious difficulties. The authors report a comprehensive forensic chemical, morphometric, and pathomorphological study of the activity of ethanol-oxidizing enzyme systems in the internal organs. The results of histochemical examination provide a basis for the extension of diagnostic potential of the available methods and the enhancement of the objective value of expert reports. PMID:21866846

  16. The silk protein, sericin, protects against cell death caused by acute serum deprivation in insect cell culture.

    PubMed

    Takahashi, Masakazu; Tsujimoto, Kazuhisa; Yamada, Hideyuki; Takagi, Hiroshi; Nakamori, Shigeru

    2003-11-01

    Sericin is the silk protein that covers fibroin fibers and functions as a 'glue' in the cocoons of silkworms, and its most abundant component, Ser1, contains repeats of Ser- and Thr-rich 38 amino acid residues. The viability of Sf9 insect cells was 20, 57 and 49% on the fifth day and 41, 91 and 70% on the ninth day after serum deprivation in the presence of no additives, 3000 microg sericin hydrolysate and 350 microg SerD (the peptide containing the two repetitive units) ml(-1), respectively. Thus, the sericin samples were useful in preventing cell death and promoting cellular growth after acute serum deprivation. PMID:14677702

  17. Mechanisms of Indirect Acute Lung Injury: A Novel Role for the Co-Inhibitory Receptor, Programmed Death-1 (PD-1)

    PubMed Central

    Monaghan, Sean F.; Thakkar, Rajan K.; Heffernan, Daithi S.; Huang, Xin; Chung, Chun-Shiang; Lomas-Neira, Joanne; Cioffi, William G.; Ayala, Alfred

    2011-01-01

    Objective To determine the contribution of PD-1 in the morbidity and mortality associated with the development of indirect-acute lung injury Summary Background Data The immune cell interaction(s) leading to indirect-acute lung injury are not completely understood. In this respect, while we have recently shown that the murine cell surface co-inhibitory receptor, Programmed Cell death receptor (PD)-1, has a role in septic morbidity/mortality that is mediated in part through the effects on the innate immune arm. However, it is not know if PD-1 has a role in the development of indirect-acute lung injury and how this may be mediated at a cellular level. Methods PD-1 −/− mice were used in a murine model of indirect-acute lung injury (hemorrhagic shock followed 24 h after with cecal ligation & puncture-septic challenge) and compared to wild type controls. Groups were initially compared for survival and subsequently for markers of pulmonary inflammation, influx of lymphocytes and neutrophils, and expression of PD-1 and its ligand, PD-L1. In addition, peripheral blood leukocytes of patients with indirect-acute lung injury were examined to assess changes in cellular PD-1 expression relative to mortality. Results PD-1 −/− mice showed improved survival compared to wild type controls. In the mouse lung, CD4+, CD11c+ and Gr-1+ cells showed increased PD-1 expression in response to indirect-acute lung injury. However, while the rise in BAL fluid protein concentrations, lung IL-6, and lung MCP-1 were similar between PD-1 −/− and wild type animals subjected to indirect acute lung injury, the PD-1 −/− animals that were subjected to shock/septic challenge had reduced CD4:CD8 ratios, TNF-α levels, MPO activity, and caspase 3 levels in the lung. Comparatively, we observed that humans, who survived their acute lung injury, had significantly lower expression of PD-1 on T cells. Conclusions PD-1 expression contributes to mortality following the induction of indirect-acute

  18. 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

  19. Influence of pesticide regulation on acute poisoning deaths in Sri Lanka.

    PubMed Central

    Roberts, Darren M.; Karunarathna, Ayanthi; Buckley, Nick A.; Manuweera, Gamini; Sheriff, M. H. Rezvi; Eddleston, Michael

    2003-01-01

    OBJECTIVES: To assess in a developing Asian country the impact of pesticide regulation on the number of deaths from poisoning. These regulations, which were implemented in Sri Lanka from the 1970s, aimed to reduce the number of deaths - the majority from self-poisoning - by limiting the availability and use of highly toxic pesticides. METHODS: Information on legislative changes was obtained from the Ministry of Agriculture, national and district hospital admission data were obtained from the Sri Lanka Health Statistics Unit, and individual details of deaths by pesticide poisoning were obtained from a manual review of patients' notes and intensive care unit records in Anuradhapura. FINDINGS: Between 1986 and 2000, the total national number of admissions due to poisoning doubled, and admissions due to pesticide poisoning increased by more than 50%. At the same time, the case fatality proportion (CFP) fell for total poisonings and for poisonings due to pesticides. In 1991_92, 72% of pesticide-induced deaths in Anuradhapura were caused by organophosphorus (OP) and carbamate pesticides - in particular, the WHO class I OPs monocrotophos and methamidophos. From 1991, the import of these pesticides was reduced gradually until they were banned for routine use in January 1995, with a corresponding fall in deaths. Unfortunately, their place in agricultural practice was taken by the WHO class II organochlorine endosulfan, which led to a rise in deaths from status epilepticus - from one in 1994 to 50 in 1998. Endosulfan was banned in 1998, and over the following three years the number of endosulfan deaths fell to three. However, at the end of the decade, the number of deaths from pesticides was at a similar level to that of 1991, with WHO class II OPs causing the most deaths. Although these drugs are less toxic than class I OPs, the management of class II OPs remains difficult because they are, nevertheless, still highly toxic, and their toxicity is exacerbated by the paucity

  20. Neuronal death induced by misfolded prion protein is due to NAD+ depletion and can be relieved in vitro and in vivo by NAD+ replenishment

    PubMed Central

    Zhou, Minghai; Ottenberg, Gregory; Sferrazza, Gian Franco; Hubbs, Christopher; Fallahi, Mohammad; Rumbaugh, Gavin; Brantley, Alicia F.

    2015-01-01

    The mechanisms of neuronal death in protein misfolding neurodegenerative diseases such as Alzheimer’s, Parkinson’s and prion diseases are poorly understood. We used a highly toxic misfolded prion protein (TPrP) model to understand neurotoxicity induced by prion protein misfolding. We show that abnormal autophagy activation and neuronal demise is due to severe, neuron-specific, nicotinamide adenine dinucleotide (NAD+) depletion. Toxic prion protein-exposed neuronal cells exhibit dramatic reductions of intracellular NAD+ followed by decreased ATP production, and are completely rescued by treatment with NAD+ or its precursor nicotinamide because of restoration of physiological NAD+ levels. Toxic prion protein-induced NAD+ depletion results from PARP1-independent excessive protein ADP-ribosylations. In vivo, toxic prion protein-induced degeneration of hippocampal neurons is prevented dose-dependently by intracerebral injection of NAD+. Intranasal NAD+ treatment of prion-infected sick mice significantly improves activity and delays motor impairment. Our study reveals NAD+ starvation as a novel mechanism of autophagy activation and neurodegeneration induced by a misfolded amyloidogenic protein. We propose the development of NAD+ replenishment strategies for neuroprotection in prion diseases and possibly other protein misfolding neurodegenerative diseases. PMID:25678560

  1. 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.

  2. Kainic acid-induced neurodegeneration and activation of inflammatory processes in organotypic hippocampal slice cultures: treatment with cyclooxygenase-2 inhibitor does not prevent neuronal death.

    PubMed

    Järvelä, Juha T; Ruohonen, Saku; Kukko-Lukjanov, Tiina-Kaisa; Plysjuk, Anna; Lopez-Picon, Francisco R; Holopainen, Irma E

    2011-06-01

    In the postnatal rodent hippocampus status epilepticus (SE) leads to age- and region-specific excitotoxic neuronal damage, the precise mechanisms of which are still incompletely known. Recent studies suggest that the activation of inflammatory responses together with glial cell reactivity highly contribute to excitotoxic neuronal damage. However, pharmacological tools to attenuate their activation in the postnatal brain are still poorly elucidated. In this study, we investigated the role of inflammatory mediators in kainic acid (KA)-induced neuronal damage in organotypic hippocampal slice cultures (OHCs). A specific cyclooxygenase-2 (COX-2) inhibitor N-[2-(cyclohexyloxy)-4-nitrophenyl]-methanesulfonamide (NS-398) was used to study whether or not it could ameliorate neuronal death. Our results show that KA treatment (24 h) resulted in a dose-dependent degeneration of CA3a/b pyramidal neurons. Furthermore, COX-2 immunoreactivity was pronouncedly enhanced particularly in CA3c pyramidal neurons, microglial and astrocyte morphology changed from a resting to active appearance, the expression of the microglial specific protein, Iba1, increased, and prostaglandin E₂ (PGE₂) production increased. These indicated the activation of inflammatory processes. However, the expression of neither proinflammatory cytokines, i.e. tumour necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β), nor the anti-inflammatory cytokine IL-10 mRNA was significantly altered by KA treatment as studied by real-time PCR. Despite activation of an array of inflammatory processes, neuronal damage could not be rescued either with the combined pre- and co-treatment with a specific COX-2 inhibitor, NS-398. Our results suggest that KA induces activation of a repertoire of inflammatory processes in immature OHCs, and that the timing of anti-inflammatory treatment to achieve neuroprotection is a challenge due to developmental properties and the complexity of inflammatory processes activated by

  3. 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

  4. 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

  5. Cytotoxicity of synthetic cannabinoids on primary neuronal cells of the forebrain: the involvement of cannabinoid CB{sub 1} receptors and apoptotic cell death

    SciTech Connect

    Tomiyama, Ken-ichi; Funada, Masahiko

    2014-01-01

    The abuse of herbal products containing synthetic cannabinoids has become an issue of public concern. The purpose of this paper was to evaluate the acute cytotoxicity of synthetic cannabinoids on mouse brain neuronal cells. Cytotoxicity induced by synthetic cannabinoid (CP-55,940, CP-47,497, CP-47,497-C8, HU-210, JWH-018, JWH-210, AM-2201, and MAM-2201) was examined using forebrain neuronal cultures. These synthetic cannabinoids induced cytotoxicity in the forebrain cultures in a concentration-dependent manner. The cytotoxicity was suppressed by preincubation with the selective CB{sub 1} receptor antagonist AM251, but not with the selective CB{sub 2} receptor antagonist AM630. Furthermore, annexin-V-positive cells were found among the treated forebrain cells. Synthetic cannabinoid treatment induced the activation of caspase-3, and preincubation with a caspase-3 inhibitor significantly suppressed the cytotoxicity. These synthetic cannabinoids induced apoptosis through a caspase-3-dependent mechanism in the forebrain cultures. Our results indicate that the cytotoxicity of synthetic cannabinoids towards primary neuronal cells is mediated by the CB{sub 1} receptor, but not by the CB{sub 2} receptor, and further suggest that caspase cascades may play an important role in the apoptosis induced by these synthetic cannabinoids. In conclusion, excessive synthetic cannabinoid abuse may present a serious acute health concern due to neuronal damage or deficits in the brain. - Highlights: • Synthetic cannabinoids (classical cannabinoids, non-classical cannabinoids, and aminoalkylindole derivatives) induce cytotoxicity in mouse forebrain cultures. • Synthetic cannabinoid-induced cytotoxicity towards forebrain cultures is mediated by the CB{sub 1} receptor, but not by the CB{sub 2} receptor, and involves caspase-dependent apoptosis. • A high concentration of synthetic cannabinoids may be toxic to neuronal cells that express CB{sub 1} receptors.

  6. Progranulin protects against endotoxin-induced acute kidney injury by downregulating renal cell death and inflammatory responses in mice.

    PubMed

    Xu, Xiaoying; Gou, Linfeng; Zhou, Meng; Yang, Fusheng; Zhao, Yihan; Feng, Tingting; Shi, Peikun; Ghavamian, Armin; Zhao, Weiming; Yu, Yuan; Lu, Yi; Yi, Fan; Liu, Guangyi; Tang, Wei

    2016-09-01

    Progranulin (PGRN), a pluripotent secreted growth factor, is involved in various physiologic and disease processes. However, the role of PGRN in endotoxin-induced septic acute kidney injury (AKI) remains unknown. The objective of this study is to investigate the protective effects of PGRN on an endotoxin-induced AKI mouse model by using PGRN-deficient mice and recombinant PGRN (rPGRN) pretreatment. PGRN levels were increased in kidneys of wild-type (WT) mice at 6 and 24h after lipopolysaccharide (LPS) injection. Renal function detection, hematoxylin and eosin staining, immunohistochemical staining, ELISA and in situ terminal deoxynucleotidyl transferase-mediated uridine triphosphate nick-end labeling were used to reveal tissue injury, inflammatory cell infiltration, production of inflammatory mediators and cell death in mouse kidneys after LPS injection. PGRN deficiency resulted in severe kidney injury and increased apoptotic death, inflammatory cell infiltration, production of pro-inflammatory mediators and the expression and nucleus-to-cytoplasmic translocation of HMGB1 in the kidney. In addition, rPGRN administration before LPS treatment ameliorated the endotoxin-induced AKI in WT mice. PGRN may be a novel biologic agent with therapeutic potential for endotoxin-induced septic AKI possibly by inhibiting LPS-induced renal cell death and inflammatory responses in mice. PMID:27367257

  7. T315 Decreases Acute Myeloid Leukemia Cell Viability through a Combination of Apoptosis Induction and Autophagic Cell Death.

    PubMed

    Chiu, Chang-Fang; Weng, Jing-Ru; Jadhav, Appaso; Wu, Chia-Yung; Sargeant, Aaron M; Bai, Li-Yuan

    2016-01-01

    T315, an integrin-linked kinase (ILK) inhibitor, has been shown to suppress the proliferation of breast cancer, stomach cancer and chronic lymphocytic leukemia cells. Here we demonstrate that T315 decreases cell viability of acute myeloid leukemia (AML) cell lines (HL-60 and THP-1) and primary leukemia cells from AML patients in a dose-responsive manner. Normal human bone marrow cells are less sensitive than leukemia cells to T315. T315 down regulates protein kinase B (Akt) and p-Akt and induces caspase activation, poly-ADP-ribose polymerase (PARP) cleavage, apoptosis and autophagy through an ILK-independent manner. Interestingly, pretreatment with autophagy inhibitors rescues cells from apoptosis and concomitant PARP cleavage, which implicates a key role of autophagic cell death in T315-mediated cytotoxicity. T315 also demonstrates efficacy in vivo, suppressing the growth of THP-1 xenograft tumors in athymic nude mice when administered intraperitoneally. This study shows that autophagic cell death and apoptosis cooperatively contribute to the anticancer activity of T315 in AML cells. In conclusion, the complementary roles of apoptotic and autophagic cell death should be considered in the future assessment of the translational value of T315 in AML therapy. PMID:27537872

  8. T315 Decreases Acute Myeloid Leukemia Cell Viability through a Combination of Apoptosis Induction and Autophagic Cell Death

    PubMed Central

    Chiu, Chang-Fang; Weng, Jing-Ru; Jadhav, Appaso; Wu, Chia-Yung; Sargeant, Aaron M.; Bai, Li-Yuan

    2016-01-01

    T315, an integrin-linked kinase (ILK) inhibitor, has been shown to suppress the proliferation of breast cancer, stomach cancer and chronic lymphocytic leukemia cells. Here we demonstrate that T315 decreases cell viability of acute myeloid leukemia (AML) cell lines (HL-60 and THP-1) and primary leukemia cells from AML patients in a dose-responsive manner. Normal human bone marrow cells are less sensitive than leukemia cells to T315. T315 down regulates protein kinase B (Akt) and p-Akt and induces caspase activation, poly-ADP-ribose polymerase (PARP) cleavage, apoptosis and autophagy through an ILK-independent manner. Interestingly, pretreatment with autophagy inhibitors rescues cells from apoptosis and concomitant PARP cleavage, which implicates a key role of autophagic cell death in T315-mediated cytotoxicity. T315 also demonstrates efficacy in vivo, suppressing the growth of THP-1 xenograft tumors in athymic nude mice when administered intraperitoneally. This study shows that autophagic cell death and apoptosis cooperatively contribute to the anticancer activity of T315 in AML cells. In conclusion, the complementary roles of apoptotic and autophagic cell death should be considered in the future assessment of the translational value of T315 in AML therapy. PMID:27537872

  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. Temporal Resolution of Misfolded Prion Protein Transport, Accumulation, Glial Activation, and Neuronal Death in the Retinas of Mice Inoculated with Scrapie.

    PubMed

    West Greenlee, M Heather; Lind, Melissa; Kokemuller, Robyn; Mammadova, Najiba; Kondru, Naveen; Manne, Sireesha; Smith, Jodi; Kanthasamy, Anumantha; Greenlee, Justin

    2016-09-01

    Currently, there is a lack of pathological landmarks to describe the progression of prion disease in vivo. Our goal was to use an experimental model to determine the temporal relationship between the transport of misfolded prion protein (PrP(Sc)) from the brain to the retina, the accumulation of PrP(Sc) in the retina, the response of the surrounding retinal tissue, and loss of neurons. Retinal samples from mice inoculated with RML scrapie were collected at 30, 60, 90, 105, and 120 days post inoculation (dpi) or at the onset of clinical signs of disease (153 dpi). Retinal homogenates were tested for prion seeding activity. Antibody staining was used to assess accumulation of PrP(Sc) and the resulting response of retinal tissue. Loss of photoreceptors was used as a measure of neuronal death. PrP(Sc) seeding activity was first detected in all samples at 60 dpi. Accumulation of PrP(Sc) and coincident activation of retinal glia were first detected at 90 dpi. Activation of microglia was first detected at 105 dpi, but neuronal death was not detectable until 120 dpi. Our results demonstrate that by using the retina we can resolve the temporal separation between several key events in the pathogenesis of prion disease. PMID:27521336

  11. Loss of the transcription factor Meis1 prevents sympathetic neurons target-field innervation and increases susceptibility to sudden cardiac death

    PubMed Central

    Bouilloux, Fabrice; Thireau, Jérôme; Ventéo, Stéphanie; Farah, Charlotte; Karam, Sarah; Dauvilliers, Yves; Valmier, Jean; Copeland, Neal G; Jenkins, Nancy A; Richard, Sylvain; Marmigère, Frédéric

    2016-01-01

    Although cardio-vascular incidents and sudden cardiac death (SCD) are among the leading causes of premature death in the general population, the origins remain unidentified in many cases. Genome-wide association studies have identified Meis1 as a risk factor for SCD. We report that Meis1 inactivation in the mouse neural crest leads to an altered sympatho-vagal regulation of cardiac rhythmicity in adults characterized by a chronotropic incompetence and cardiac conduction defects, thus increasing the susceptibility to SCD. We demonstrated that Meis1 is a major regulator of sympathetic target-field innervation and that Meis1 deficient sympathetic neurons die by apoptosis from early embryonic stages to perinatal stages. In addition, we showed that Meis1 regulates the transcription of key molecules necessary for the endosomal machinery. Accordingly, the traffic of Rab5+ endosomes is severely altered in Meis1-inactivated sympathetic neurons. These results suggest that Meis1 interacts with various trophic factors signaling pathways during postmitotic neurons differentiation. DOI: http://dx.doi.org/10.7554/eLife.11627.001 PMID:26857994

  12. Akt attenuates apoptotic death through phosphorylation of H2A under hydrogen peroxide-induced oxidative stress in PC12 cells and hippocampal neurons

    PubMed Central

    Park, Ji Hye; Kim, Chung Kwon; Lee, Sang Bae; Lee, Kyung-Hoon; Cho, Sung-Woo; Ahn, Jee-Yin

    2016-01-01

    Although the essential role of protein kinase B (PKB)/Akt in cell survival signaling has been clearly established, the mechanism by which Akt mediates the cellular response to hydrogen peroxide (H2O2)-induced oxidative stress remains unclear. We demonstrated that Akt attenuated neuronal apoptosis through direct association with histone 2A (H2A) and phosphorylation of H2A at threonine 17. At early time points during H2O2 exposure of PC12 cells and primary hippocampal neurons, when the cells can tolerate the level of DNA damage, Akt was activated and phosphorylated H2A, leading to inhibition of apoptotic death. At later time points, Akt delivered the NAD+-dependent protein deacetylase Sirtuin 2 (Sirt 2) to the vicinity of phosphorylated H2A in response to irreversible DNA damage, thereby inducing H2A deacetylation and subsequently leading to apoptotic death. Ectopically expressed T17A-substituted H2A minimally interacted with Akt and failed to prevent apoptosis under oxidative stress. Thus Akt-mediated H2A phosphorylation has an anti-apoptotic function in conditions of H2O2-induced oxidative stress in neurons and PC12 cells. PMID:26899247

  13. Dexamethasone-induced acute excitotoxic cell death in the developing brain.

    PubMed

    Lanshakov, Dmitriy A; Sukhareva, Ekaterina V; Kalinina, Tatjana S; Dygalo, Nikolay N

    2016-07-01

    There is substantial evidence that the use of glucocorticoids in neonates is associated with an increased risk of neurodevelopmental disorders. However, it remains unclear how treatment with low doses of dexamethasone (DEX) may result in behavioral abnormalities without evident signs of immediate neurotoxicity in the neonatal brain. It is possible that cells vulnerable to the pro-apoptotic effects of low doses of DEX escaped detection due to their small number in the developing brain. In agreement with this suggestion, low-dose DEX treatment (0.2mg/kg) failed to induce apoptosis in the cortex or hippocampus proper of neonatal rats. However, this treatment was capable of inducing apoptosis specifically in the dorsal subiculum via a two-step mechanism that involves glutamate excitotoxicity. Application of DEX leads to increased activity of CA1/CA3 hippocampal MAP2-positive neurons, as determined by c-Fos expression at 0.5-1h after DEX injection. Five hours later, the apoptotic markers (fragmented nuclei, active caspase-3 and TUNEL labeling) increased in the dorsal subiculum, which receives massive glutamatergic input from CA1 neurons. Pretreatment with memantine, an antagonist of glutamate NMDA receptors, dose dependently blocked the DEX-induced expression of apoptotic markers in the subicular neurons and astrocytes. These findings provide new insights into the mechanisms of DEX-induced neurotoxicity as well as on the mechanism of therapeutic action of antagonists of NMDA receptors against neurobehavioral disorders caused by neonatal exposure to glucocorticoids. PMID:26873551

  14. S-Nitrosylation of parkin as a novel regulator of p53-mediated neuronal cell death in sporadic Parkinson’s disease

    PubMed Central

    2013-01-01

    Background Mutations in the gene encoding parkin, a neuroprotective protein with dual functions as an E3 ubiquitin ligase and transcriptional repressor of p53, are linked to familial forms of Parkinson’s disease (PD). We hypothesized that oxidative posttranslational modification of parkin by environmental toxins may contribute to sporadic PD. Results We first demonstrated that S-nitrosylation of parkin decreased its activity as a repressor of p53 gene expression, leading to upregulation of p53. Chromatin immunoprecipitation as well as gel-shift assays showed that parkin bound to the p53 promoter, and this binding was inhibited by S-nitrosylation of parkin. Additionally, nitrosative stress induced apoptosis in cells expressing parkin, and this death was, at least in part, dependent upon p53. In primary mesencephalic cultures, pesticide-induced apoptosis was prevented by inhibition of nitric oxide synthase (NOS). In a mouse model of pesticide-induced PD, both S-nitrosylated (SNO-)parkin and p53 protein levels were increased, while administration of a NOS inhibitor mitigated neuronal death in these mice. Moreover, the levels of SNO-parkin and p53 were simultaneously elevated in postmortem human PD brain compared to controls. Conclusions Taken together, our data indicate that S-nitrosylation of parkin, leading to p53-mediated neuronal cell death, contributes to the pathophysiology of sporadic PD. PMID:23985028

  15. Minocycline attenuates both OGD-induced HMGB1 release and HMGB1-induced cell death in ischemic neuronal injury in PC12 cells

    SciTech Connect

    Kikuchi, Kiyoshi; Kawahara, Ko-ichi; Biswas, Kamal Krishna; Ito, Takashi; Tancharoen, Salunya; Morimoto, Yoko; Matsuda, Fumiyo; Oyama, Yoko; Takenouchi, Kazunori; Miura, Naoki; Arimura, Noboru; Nawa, Yuko; Meng, Xiaojie; Shrestha, Binita; Arimura, Shinichiro; and others

    2009-07-24

    High mobility group box-1 (HMGB1), a non-histone DNA-binding protein, is massively released into the extracellular space from neuronal cells after ischemic insult and exacerbates brain tissue damage in rats. Minocycline is a semisynthetic second-generation tetracycline antibiotic which has recently been shown to be a promising neuroprotective agent. In this study, we found that minocycline inhibited HMGB1 release in oxygen-glucose deprivation (OGD)-treated PC12 cells and triggered the activation of p38mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinases (ERK1/2). The ERK kinase (MEK)1/2 inhibitor U-0126 and p38MAPK inhibitor SB203580 blocked HMGB1 release in response to OGD. Furthermore, HMGB1 triggered cell death in a dose-dependent fashion. Minocycline significantly rescued HMGB1-induced cell death in a dose-dependent manner. In light of recent observations as well as the good safety profile of minocycline in humans, we propose that minocycline might play a potent neuroprotective role through the inhibition of HMGB1-induced neuronal cell death in cerebral infarction.

  16. Levodopa Deactivates Enzymes that Regulate Thiol-Disulfide Homeostasis and Promotes Neuronal Cell Death - Implications for Therapy of Parkinson’s Disease

    PubMed Central

    Sabens, Elizabeth A.; Distler, Anne M.; Mieyal, John J.

    2011-01-01

    Parkinson’s disease (PD), characterized by dopaminergic neuronal loss, is attributed to oxidative stress, diminished glutathione (GSH), mitochondrial dysfunction, and protein aggregation. Treatment of PD involves chronic administration of Levodopa (L-DOPA) which is a pro-oxidant and may disrupt sulfhydryl homeostasis. The goal of current studies is to elucidate the effects of L-DOPA on thiol homeostasis in a model akin to PD, i.e., immortalized dopaminergic neurons (SHSY5Y cells) with diminished GSH content. These neurons exhibit hypersensitivity to L-DOPA-induced cell death, which is attributable to concomitant inhibition of the intracellular thiol disulfide oxidoreductase enzymes. Glutaredoxin (Grx) was deactivated in a dose-dependent fashion; but its content was unaffected. Glutathione disulfide (GSSG) reductase (GR) activity was not altered. Selective knockdown of Grx resulted in increased apoptosis, documenting the role of the Grx system in neuronal survival. L-DOPA treatments also led to decreased activities of thioredoxin (Trx) and thioredoxin reductase (TR), concomitant with diminution of their cellular contents. Selective chemical inhibition of TR activity led to increased apoptosis, documenting the Trx system’s contribution to neuronal viability. To investigate the mechanism of inhibition at the molecular level the isolated enzymes were each treated with oxidized L-DOPA. GR, Trx, and TR activities were little affected. However, Grx was inactivated in a time- and concentration-dependent fashion indicative of irreversible adduction of dopaquinone to its nucleophilic active site Cys-22, consistent with intracellular loss of Grx activity but not Grx protein content after L-DOPA treatment. Overall L-DOPA is shown to impair the collaborative contributions of the Grx and Trx systems to neuron survival. PMID:20141169

  17. CLINICAL CHARACTERISTICS, OUTCOMES AND RISK FACTORS FOR DEATH AMONG CRITICALLY ILL PATIENTS WITH HIV-RELATED ACUTE KIDNEY INJURY

    PubMed Central

    LUNA, Leonardo Duarte Sobreira; SOARES, Douglas de Sousa; JUNIOR, Geraldo Bezerra da SILVA; CAVALCANTE, Malena Gadelha; MALVEIRA, Lara Raissa Cavalcante; MENESES, Gdayllon Cavalcante; PEREIRA, Eanes Delgado Barros; DAHER, Elizabeth De Francesco

    2016-01-01

    SUMMARY Background: The aim of this study is to describe clinical characteristics, outcomes and risk factors for death among patients with HIV-related acute kidney injury (AKI) admitted to an intensive care unit (ICU). Methods: A retrospective study was conducted with HIV-infected AKI patients admitted to the ICU of an infectious diseases hospital in Fortaleza, Brazil. All the patients with confirmed diagnosis of HIV and AKI admitted from January 2004 to December 2011 were included. A comparison between survivors and non-survivors was performed. Risk factors for death were investigated. Results: Among 256 AKI patients admitted to the ICU in the study period, 73 were identified as HIV-infected, with a predominance of male patients (83.6%), and the mean age was 41.2 ± 10.4 years. Non-survivor patients presented higher APACHE II scores (61.4 ± 19 vs. 38.6 ± 18, p = 0.004), used more vasoconstrictors (70.9 vs. 37.5%, p = 0.02) and needed more mechanical ventilation - MV (81.1 vs. 35.3%, p = 0.001). There were 55 deaths (75.3%), most of them (53.4%) due to septic shock. Independent risk factors for mortality were septic shock (OR = 14.2, 95% CI = 2.0-96.9, p = 0.007) and respiratory insufficiency with need of MV (OR = 27.6, 95% CI = 5.0-153.0, p < 0.001). Conclusion: Non-survivor HIV-infected patients with AKI admitted to the ICU presented higher severity APACHE II scores, more respiratory damage and hemodynamic impairment than survivors. Septic shock and respiratory insufficiency were independently associated to death. PMID:27410912

  18. Marked changes in dendritic structure and spine density precede significant neuronal death in vulnerable cortical pyramidal neuron populations in the SOD1(G93A) mouse model of amyotrophic lateral sclerosis.

    PubMed

    Fogarty, Matthew J; Mu, Erica W H; Noakes, Peter G; Lavidis, Nickolas A; Bellingham, Mark C

    2016-01-01

    Amyotrophic lateral sclerosis (ALS) is characterised by the death of upper (corticospinal) and lower motor neurons (MNs) with progressive muscle weakness. This incurable disease is clinically heterogeneous and its aetiology remains unknown. Increased excitability of corticospinal MNs has been observed prior to symptoms in human and rodent studies. Increased excitability has been correlated with structural changes in neuronal dendritic arbors and spines for decades. Here, using a modified Golgi-Cox staining method, we have made the first longitudinal study examining the dendrites of pyramidal neurons from the motor cortex, medial pre-frontal cortex, somatosensory cortex and entorhinal cortex of hSOD1(G93A) (SOD1) mice compared to wild-type (WT) littermate controls at postnatal (P) days 8-15, 28-35, 65-75 and 120. Progressive decreases in dendritic length and spine density commencing at pre-symptomatic ages (P8-15 or P28-35) were observed in layer V pyramidal neurons within the motor cortex and medial pre-frontal cortex of SOD1 mice compared to WT mice. Spine loss without concurrent dendritic pathology was present in the pyramidal neurons of the somatosensory cortex from disease-onset (P65-75). Our results from the SOD1 model suggest that dendritic and dendritic spine changes foreshadow and underpin the neuromotor phenotypes present in ALS and may contribute to the varied cognitive, executive function and extra-motor symptoms commonly seen in ALS patients. Determining if these phenomena are compensatory or maladaptive may help explain differential susceptibility of neurons to degeneration in ALS. PMID:27488828

  19. 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

  20. Loss of C9ORF72 impairs autophagy and synergizes with polyQ Ataxin-2 to induce motor neuron dysfunction and cell death.

    PubMed

    Sellier, Chantal; Campanari, Maria-Letizia; Julie Corbier, Camille; Gaucherot, Angeline; Kolb-Cheynel, Isabelle; Oulad-Abdelghani, Mustapha; Ruffenach, Frank; Page, Adeline; Ciura, Sorana; Kabashi, Edor; Charlet-Berguerand, Nicolas

    2016-06-15

    An intronic expansion of GGGGCC repeats within the C9ORF72 gene is the most common genetic cause of amyotrophic lateral sclerosis and frontotemporal dementia (ALS-FTD). Ataxin-2 with intermediate length of polyglutamine expansions (Ataxin-2 Q30x) is a genetic modifier of the disease. Here, we found that C9ORF72 forms a complex with the WDR41 and SMCR8 proteins to act as a GDP/GTP exchange factor for RAB8a and RAB39b and to thereby control autophagic flux. Depletion of C9orf72 in neurons partly impairs autophagy and leads to accumulation of aggregates of TDP-43 and P62 proteins, which are histopathological hallmarks of ALS-FTD SMCR8 is phosphorylated by TBK1 and depletion of TBK1 can be rescued by phosphomimetic mutants of SMCR8 or by constitutively active RAB39b, suggesting that TBK1, SMCR8, C9ORF72, and RAB39b belong to a common pathway regulating autophagy. While depletion of C9ORF72 only has a partial deleterious effect on neuron survival, it synergizes with Ataxin-2 Q30x toxicity to induce motor neuron dysfunction and neuronal cell death. These results indicate that partial loss of function of C9ORF72 is not deleterious by itself but synergizes with Ataxin-2 toxicity, suggesting a double-hit pathological mechanism in ALS-FTD. PMID:27103069

  1. Genistein inhibition of OGD-induced brain neuron death correlates with its modulation of apoptosis, voltage-gated potassium and sodium currents and glutamate signal pathway.

    PubMed

    Ma, Xue-Ling; Zhang, Feng; Wang, Yu-Xiang; He, Cong-Cong; Tian, Kun; Wang, Hong-Gang; An, Di; Heng, Bin; Liu, Yan-Qiang

    2016-07-25

    In the present study, we established an in vitro model of hypoxic-ischemia via exposing primary neurons of newborn rats to oxygen-glucose deprivation (OGD) and observing the effects of genistein, a soybean isoflavone, on hypoxic-ischemic neuron viability, apoptosis, voltage-activated potassium (Kv) and sodium (Nav) currents, and glutamate receptor subunits. The results indicated that OGD exposure reduced the viability and increased the apoptosis of brain neurons. Meanwhile, OGD exposure caused changes in the current-voltage curves and current amplitude values of voltage-activated potassium and sodium currents; OGD exposure also decreased GluR2 expression and increased NR2 expression. However, genistein at least partially reversed the effects caused by OGD. The results suggest that hypoxic-ischemia-caused neuronal apoptosis/death is related to an increase in K(+) efflux, a decrease in Na(+) influx, a down-regulation of GluR2, and an up-regulation of NR2. Genistein may exert some neuroprotective effects via the modulation of Kv and Nav currents and the glutamate signal pathway, mediated by GluR2 and NR2. PMID:27238724

  2. Pancortin-2 interacts with WAVE1 and Bcl-xL in a mitochondria-associated protein complex that mediates ischemic neuronal death.

    PubMed

    Cheng, Aiwu; Arumugam, Thiruma V; Liu, Dong; Khatri, Rina G; Mustafa, Khadija; Kwak, Seung; Ling, Huai-Ping; Gonzales, Cathleen; Xin, Ouyang; Jo, Dong-Gyu; Guo, Zhihong; Mark, Robert J; Mattson, Mark P

    2007-02-14

    The actin-modulating protein Wiskott-Aldrich syndrome protein verprolin homologous-1 (WAVE1) and a novel CNS-specific protein, pancortin, are highly enriched in adult cerebral cortex, but their functions are unknown. Here we show that WAVE1 and pancortin-2 interact in a novel cell death cascade in adult, but not embryonic, cerebral cortical neurons. Focal ischemic stroke induces the formation of a protein complex that includes pancortin-2, WAVE1, and the anti-apoptotic protein Bcl-xL. The three-protein complex is associated with mitochondria resulting in increased association of Bax with mitochondria, cytochrome c release, and neuronal apoptosis. In pancortin null mice generated using a Cre-loxP system, ischemia-induced WAVE1-Bcl-xL interaction is diminished, and cortical neurons in these mice are protected against ischemic injury. Thus, pancortin-2 is a mediator of ischemia-induced apoptosis of neurons in the adult cerebral cortex and functions in a novel mitochondrial/actin-associated protein complex that sequesters Bcl-xL. PMID:17301160

  3. Mitochondria toxin-induced acute cochlear cell death indicates cellular activity-correlated energy consumption.

    PubMed

    Zou, Jing; Zhang, Ya; Zhang, Weikai; Poe, Dennis; Zhai, Suoqiang; Yang, Shiming; Pyykkö, Ilmari

    2013-09-01

    The different cell types within the cochlea may have a specific contribution to the pathological changes during metabolism failure, which may provide clues for developing novel strategies for inner ear therapy. In order to evaluate activity-correlated cell death during metabolism failure in the cochlea, 3-nitropropionic acid was used to irreversibly inhibit the respiratory chain. Dose-response of the cochlear cells to 3-nitropropionic acid was analyzed in vitro. 3-Nitropropionic acid was administered onto the round window of guinea pigs. Cell death was identified by terminal transferase labeling the free 3'OH breaks in the DNA strands in vivo and propidium iodide nuclear permeation in vitro. As a result, 23.6 and 96.3 % cell death were induced by 10 and 100 mM 3-nitropropionic acid, respectively, in vitro. In the guinea pigs, 500 mM 3-nitropropionic acid induced vestibular dysfunction and severe to profound hearing losses. The cells that are the most sensitive to 3-nitropropionic acid treatment include the stria marginal and intermediate cells, epithelial cells of the Reissner's membrane, and spiral ligament fibrocytes (types II and V). Moderate sensitive cells were satellite fibrocytes of the spiral limbic central zone, osteocytes of the cochlear shell, hair cells, and spiral ganglion cells. Reduction of neurofilament in the soma and periphery processes of spiral ganglion cells occurred after the exposure. These results may be relevant to the mechanisms of injury in sudden onset sensorineural hearing loss and hazardous substance exposure-induced hearing loss. PMID:23179932

  4. NQDI-1, an inhibitor of ASK1 attenuates acute perinatal hypoxic-ischemic cerebral injury by modulating cell death

    PubMed Central

    HAO, HU; LI, SITAO; TANG, HUI; LIU, BINGQING; CAI, YAO; SHI, CONGCONG; XIAO, XIN

    2016-01-01

    Apoptosis signal-regulating kinase 1 (ASK1) is a ubiquitously expressed protein kinase, which regulates cell fate in numerous injury conditions. Therefore, ASK1 may be a promising novel therapeutic target for injury. However, the expression and distribution of ASK1 in the perinatal brain following hypoxia-ischemia (HI) remains to be elucidated. In the present study, western blotting and immunofluorescence were used to determine the expression and distribution of ASK1 and any associated downstream targets in the perinatal rat brain following HI. NQDI-1, a specific inhibitor of ASK1 was intracerebroventricularly injected following neonatal rats brain insult for neuroprotection. The results revealed an increased expression of ASK1 and this expression was localized to the neurons and astrocytes, compared with the sham controls. Additionally, it was demonstrated that the ASK1/c-Jun N-terminal kinases (JNK) pathway was involved in the brain damage following HI in neonatal rats. Notably, NQDI-1 significantly inhibited the in vivo expression levels of ASK1, phosphorylated (p-)JNK, p-c-Jun, p53 and caspase 3. Reduced acute hypoxic-ischemic cerebral injury and cell apoptosis was observed following the injection of NQDI-1. Collectively, NQDI-1 attenuated acute perinatal hypoxic-ischemic cerebral injury by inhibiting the expression of ASK1 and cell apoptosis. This may be a promising novel neuroprotective inhibitor for perinatal cerebra injury. PMID:27081917

  5. Drinking to near death--acute water intoxication leading to neurogenic stunned myocardium.

    PubMed

    Losonczy, Lia I; Lovallo, Emily; Schnorr, C Daniel; Mantuani, Daniel

    2016-01-01

    Neurogenic stunned myocardium is a rare disease entity that has been typically described as a consequence of subarachnoid hemorrhage and, less commonly, seizures. Here we describe a case of a healthy young woman who drank excessive free water causing acute hyponatremia complicated by cerebral edema and seizure, leading to cardiogenic shock from neurogenic stunned myocardium. Two days later, she had complete return of her normal cardiac function. PMID:26238098

  6. N-acetyl-l-tryptophan, but not N-acetyl-d-tryptophan, rescues neuronal cell death in models of amyotrophic lateral sclerosis.

    PubMed

    Sirianni, Ana C; Jiang, Jiying; Zeng, Jiang; Mao, Lilly L; Zhou, Shuanhu; Sugarbaker, Peter; Zhang, Xinmu; Li, Wei; Friedlander, Robert M; Wang, Xin

    2015-09-01

    Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by progressive motor neuron loss. Evidence suggests that mitochondrial dysfunction, apoptosis, oxidative stress, inflammation, glutamate excitotoxicity, and proteasomal dysfunction are all responsible for ALS pathogenesis. N-acetyl-tryptophan has been identified as an inhibitor of mitochondrial cytochrome c release and therefore is a potential neuroprotective agent. By quantifying cell death, we demonstrate that N-acetyl-l-tryptophan (L-NAT) and N-acetyl-DL-tryptophan are neuroprotective in NSC-34 motor neuron-like cells and/or primary motor neurons, while their isomer N-acetyl-d-tryptophan has no protective effect. These findings are consistent with energy minimization and molecular modeling analysis, confirming that L-NAT generates the most stable complex with the neurokinin-1 receptor (NK-1R). L-NAT inhibits the secretion of Substance P and IL-1β (Enzyme-Linked Immunosorbent Assay and/or dot blots) and mitochondrial dysfunction by effectively inhibiting the release of cytochrome c/Smac/AIF from mitochondria into the cytoplasm and activation of apoptotic pathways, including the activation of caspase-1, -9, and -3, as well as proteasomal dysfunction through restoring chymotrypsin-like, trypsin-like, and caspase-like proteasome activity. These data provide insight into the molecular mechanisms by which L-NAT offers neuroprotection in models of ALS and suggest its potential as a novel therapeutic strategy for ALS. We demonstrate that L-NAT (N-acetyl-l-tryptophan), but not D-NAT, rescues NSC-34 cells and primary motor neurons from cell death. L-NAT inhibits the secretion of Substance P and IL-1β, and caspase-1 activation, the release of cytochrome c/Smac/AIF, and the activation of caspase -9, and -3, as well as proteasomal dysfunction. The data suggest the potential of L-NAT as a novel therapeutic strategy for amyotrophic lateral sclerosis (ALS). AIF, apoptosis-inducing factor. PMID

  7. Reciprocal modulation of C/EBP-α and C/EBP-β by IL-13 in activated microglia prevents neuronal death.

    PubMed

    Pan, Hung Chuan; Yang, Cheng Ning; Hung, Yi Wen; Lee, Wen Jane; Tien, Hsing Ru; Shen, Chin Chang; Sheehan, Jason; Chou, Chiang Ting; Sheu, Meei Ling

    2013-11-01

    In response to aggravation by activated microglia, IL-13 can significantly enhance ER stress induction, apoptosis, and death via reciprocal signaling through CCAAT/enhancer-binding protein alpha (C/EBP-α) and C/EBP-beta (C/EBP-β). This reciprocal signaling promotes neuronal survival. Since the induction of cyclooxygenase-2 (COX-2) and peroxisome proliferator-activated receptor gamma/heme oxygenase 1 (PPAR-γ/HO-1) by IL-13 plays a crucial role in the promotion of and protection from activated microglia, respectively; here, we investigated the role of IL-13 in regulating C/EBPs in activated microglia and determined its correlation with neuronal function. The results revealed that IL-13 significantly enhanced C/EBP-α/COX-2 expression and PGE2 production in LPS-treated microglial cells. Paradoxically, IL-13 abolished C/EBP-β/PPAR-γ/HO-1 expression. IL-13 also enhanced ER stress-evoked calpain activation by promoting the association of C/EBP-β and PPAR-γ. SiRNA-C/EBP-α effectively reversed the combined LPS-activated caspase-12 activation and IL-13-induced apoptosis. In contrast, siRNA-C/EBP-β partially increased microglial cell apoptosis. By NeuN immunochemistry and CD11b staining, there was improvement in the loss of CA3 neuronal cells after intrahippocampal injection of IL-13. This suggests that IL-13-enhanced PLA2 activity regulates COX-2/PGE2 expression through C/EBP-α activation. In parallel, ER stress-related calpain downregulates the PPAR-γ/HO-1 pathway via C/EBP-β and leads to aggravated death of activated microglia via IL-13, thereby preventing cerebral inflammation and neuronal injury. PMID:23881867

  8. Death from undetected acute myocardial infarction secondary to coronary artery dissection after blunt thoracic trauma.

    PubMed

    Puanglumyai, Supot; Thamtakerngkit, Somboon; Lekawanvijit, Suree

    2016-01-01

    Blunt thoracic trauma is a common occurrence in automobile accidents. Acute myocardial infarction (AMI) caused by coronary dissection following blunt thoracic trauma is rare. We report a case of healthy 24-year-old man with a history of blunt thoracic injury with subsequent undetected AMI who died of acute decompensated heart failure 4 days after the insult. The autopsy findings showed a 90% luminal narrowing of the left anterior descending coronary artery by dissecting hematoma, 3 cm in length. The myocardium revealed transmural myocardial infarction affecting apex, most part of left ventricular free wall, and interventricular septum. Both lungs were heavy, wet, and noncrepitant. Histological findings of the infarcted myocardium were consistent with 3-5 days post-AMI. Sections from both lungs revealed massive pulmonary edema, reflecting acute decompensated heart failure following a large AMI secondary to coronary dissection. Blunt thoracic trauma may obscure typical chest pain associated with cardiac ischemia especially in cases with a high tolerance for pain. PMID:26454807

  9. 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

  10. 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

  11. 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

  12. Infection-related mortality in children with acute lymphoblastic leukemia: an analysis of infectious deaths on UKALL2003.

    PubMed

    O'Connor, David; Bate, Jessica; Wade, Rachel; Clack, Rachel; Dhir, Sunita; Hough, Rachael; Vora, Ajay; Goulden, Nick; Samarasinghe, Sujith

    2014-08-14

    Although infection is the major cause of treatment-related mortality (TRM) in childhood acute lymphoblastic leukemia, factors associated with infection-related mortality (IRM) are poorly understood. To address this, we report an analysis of all 75 cases of IRM in the United Kingdom Childhood Acute Lymphoblastic Leukaemia Randomised Trial 2003 (UKALL 2003). The 5-year cumulative incidence of IRM was 2.4% (95% confidence interval [CI], 1.9%-3.0%), accounting for 75 (30%) of 249 trial deaths and 75 (64%) of 117 TRM deaths. Risk for IRM as a proportion of TRM was greater in induction than other phases (77% vs 56%; P = .02). Sixty-eight percent of cases were associated with bacterial infection (64% Gram-negative) and 20% with fungal infection. Down syndrome was the most significant risk factor for IRM (odds ratio [OR], 12.08; 95% CI, 6.54-22.32; P < .0001). In addition, there was a trend toward increased IRM in girls (OR, 1.63; 95% CI, 1.02-2.61; P = .04), as well as increasing treatment intensity (regimen B vs A: OR, 2.11 [95% CI, 1.24-3.60]; regimen C vs A: OR, 1.41 [95% CI, 0.76-2.62]; P = .02). Importantly, patients with Down syndrome were at significantly higher risk for IRM during maintenance (P = .048). Our results confirm Down syndrome as a major risk factor for IRM. Enhanced supportive care and prophylactic antibiotics should be considered in high-risk patient groups and during periods of increased risk. This study was registered at http://www.controlled-trials.com/ as #ISRCTN07355119. PMID:24904116

  13. Mechanisms of cell death in acute myocardial infarction: pathophysiological implications for treatment

    PubMed Central

    de Zwaan, C.; Daemen, M.J.A.P.; Hermens, W.Th.

    2001-01-01

    The purpose of this review is to draw attention to the growing list of pathophysiological phenomena occurring in blood, the vessel wall and cardiac tissue during myocardial infarction. A further aim is to point to the complexity of factors, contributing to cardiac dysfunction and the implications for therapy, aimed at limiting myocardial cell death. Not all pathophysiological mechanisms have been elucidated yet, indicating the necessity for further research in this area. In addition we describe interventions which have shown promise in animal studies, those which may show promise in humans, and those which are accepted as therapies of choice. PMID:25696691

  14. Poria cocos water extract (PCW) protects PC12 neuronal cells from beta-amyloid-induced cell death through antioxidant and antiapoptotic functions.

    PubMed

    Park, Yong-Hoon; Son, Il Hong; Kim, Bokyung; Lyu, Yeoung-Su; Moon, Hyung-In; Kang, Hyung-Won

    2009-11-01

    Beta-amyloid (Abeta)-induced neurotoxicity is considered to be mediated through the formation of reactive oxygen species (ROS). In this study, the protective effects of Poria cocos water extract (PCW) against Abeta1-42-induced cell death were investigated using rat pheochromocytoma (PC12) cells. Exposure of PC12 cells to the Abeta1-42 (20 microM) for 48h resulted in neuronal cell death, whereas pretreatment with PCW at the concentration range of 5-125 microg/ml reduced Abeta1-42-induced cell death. In addition, PC12 cells treated with Abeta1-42 exhibited increased accumulation of intracellular oxidative damages and underwent apoptotic death as determined by characteristic morphological alterations and positive in situ terminal end-labeling (TUNEL staining). However, PCW attenuated Abeta1-42-induced cytotoxicity, apoptotic features, and accumulation of intracellular oxidative damage. Moreover, PCW (5 to 125 microg/ml) decreased expression of apoptotic protein Bax and activity of caspase-3, but enhanced expression of anti-apoptotic protein Bcl-2. These results suggest that PCW may protect cells through suppressing the oxidative stress and the apoptosis induced by Abeta1-42, implying that PCW may be potential natural agents for Alzheimer's diseases. PMID:20099523

  15. Evidence for metal poisoning in acute deaths of large red drum (Scianeops ocellata)

    SciTech Connect

    Cardeihac, P.T.; Simpson, C.F.; White, F.H.; Thompson, N.P.; Carr, W.E.

    1981-12-01

    Two of the approximately 100 large, mature, red drum found dead or dying in Florida's Indian River and Mosquito Lagoon were examined. Determinations were made of serum electrolyte concentrations, total proteins, albumins, globulins, creatinine values, and enzyme activity. Concentrations of copper, zinc, arsenic, chromium, cadmium, mercury, lead, and selenium were determined by atomic aborption. The outstanding histological lesions were found in the gills of a moribund specimen. Results indicate that the acute episode was triggered by ingestion of copper, zinc, and arsenic. However, cadmium, mercury and chromium may have been contributory by binding with metallothionein and thus lowering tolerance to metal poisoning. (JMT)

  16. Glucocerebrosidase 1 deficient Danio rerio mirror key pathological aspects of human Gaucher disease and provide evidence of early microglial activation preceding alpha-synuclein-independent neuronal cell death

    PubMed Central

    Keatinge, Marcus; Bui, Hai; Menke, Aswin; Chen, Yu-Chia; Sokol, Anna M.; Bai, Qing; Ellett, Felix; Da Costa, Marc; Burke, Derek; Gegg, Matthew; Trollope, Lisa; Payne, Thomas; McTighe, Aimee; Mortiboys, Heather; de Jager, Sarah; Nuthall, Hugh; Kuo, Ming-Shang; Fleming, Angeleen; Schapira, Anthony H.V.; Renshaw, Stephen A.; Highley, J. Robin; Chacinska, Agnieszka; Panula, Pertti; Burton, Edward A.; O'Neill, Michael J.; Bandmann, Oliver

    2015-01-01

    Autosomal recessively inherited glucocerebrosidase 1 (GBA1) mutations cause the lysosomal storage disorder Gaucher's disease (GD). Heterozygous GBA1 mutations (GBA1+/−) are the most common risk factor for Parkinson's disease (PD). Previous studies typically focused on the interaction between the reduction of glucocerebrosidase (enzymatic) activity in GBA1+/− carriers and alpha-synuclein-mediated neurotoxicity. However, it is unclear whether other mechanisms also contribute to the increased risk of PD in GBA1+/− carriers. The zebrafish genome does not contain alpha-synuclein (SNCA), thus providing a unique opportunity to study pathogenic mechanisms unrelated to alpha-synuclein toxicity. Here we describe a mutant zebrafish line created by TALEN genome editing carrying a 23 bp deletion in gba1 (gba1c.1276_1298del), the zebrafish orthologue of human GBA1. Marked sphingolipid accumulation was already detected at 5 days post-fertilization with accompanying microglial activation and early, sustained up-regulation of miR-155, a master regulator of inflammation. gba1c.1276_1298del mutant zebrafish developed a rapidly worsening phenotype from 8 weeks onwards with striking reduction in motor activity by 12 weeks. Histopathologically, we observed marked Gaucher cell invasion of the brain and other organs. Dopaminergic neuronal cell count was normal through development but reduced by >30% at 12 weeks in the presence of ubiquitin-positive, intra-neuronal inclusions. This gba1c.1276_1298del zebrafish line is the first viable vertebrate model sharing key pathological features of GD in both neuronal and non-neuronal tissue. Our study also provides evidence for early microglial activation prior to alpha-synuclein-independent neuronal cell death in GBA1 deficiency and suggests upregulation of miR-155 as a common denominator across different neurodegenerative disorders. PMID:26376862

  17. N-methyl-N-nitrosourea-induced neuronal cell death in a large animal model of retinal degeneration in vitro.

    PubMed

    Taylor, Linnéa; Arnér, Karin; Ghosh, Fredrik

    2016-07-01

    N-methyl-N-nitrosourea (MNU) has been reported to induce photoreceptor-specific degeneration with minimal inner retinal impact in small animals in vivo. Pending its use within a retinal transplantation paradigm, we here explore the effects of MNU on outer and inner retinal neurons and glia in an in vitro large animal model of retinal degeneration. The previously described degenerative culture explant model of adult porcine retina was used and compared with explants receiving 10 or 100 μg/ml MNU (MNU10 and MNU100) supplementation. All explants were kept for 5 days in vitro, and examined for morphology as well as for glial and neuronal immunohistochemical markers. Rhodopsin-labeled photoreceptors were present in all explants. The number of cone photoreceptors (transducin), rod bipolar cells (PKC) and horizontal cells (calbindin) was significantly lower in MNU treated explants (p < 0.001). Gliosis was attenuated in MNU10 treated explants, with expression of vimentin, glial fibrillary protein (GFAP), glutamine synthetase (GS), and bFGF comparable to in vivo controls. In corresponding MNU100 counterparts, the expression of Müller cell proteins was almost extinguished. We here show that MNU causes degeneration of outer and inner retinal neurons and glia in the adult porcine retina in vitro. MNU10 explants display attenuation of gliosis, despite decreased neuronal survival compared with untreated controls. Our results have impact on the use of MNU as a large animal photoreceptor degeneration model, on tissue engineering related to retinal transplantation, and on our understanding of gliosis related neuronal degenerative cell death. PMID:27237409

  18. 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

  19. Blocking NMDA receptors delays death in rats with acute liver failure by dual protective mechanisms in kidney and brain.

    PubMed

    Cauli, Omar; González-Usano, Alba; Cabrera-Pastor, Andrea; Gimenez-Garzó, Carla; López-Larrubia, Pilar; Ruiz-Sauri, Amparo; Hernández-Rabaza, Vicente; Duszczyk, Malgorzata; Malek, Michal; Lazarewicz, Jerzy W; Carratalá, Arturo; Urios, Amparo; Miguel, Alfonso; Torregrosa, Isidro; Carda, Carmen; Montoliu, Carmina; Felipo, Vicente

    2014-06-01

    Treatment of patients with acute liver failure (ALF) is unsatisfactory and mortality remains unacceptably high. Blocking NMDA receptors delays or prevents death of rats with ALF. The underlying mechanisms remain unclear. Clarifying these mechanisms will help to design more efficient treatments to increase patient's survival. The aim of this work was to shed light on the mechanisms by which blocking NMDA receptors delays rat's death in ALF. ALF was induced by galactosamine injection. NMDA receptors were blocked by continuous MK-801 administration. Edema and cerebral blood flow were assessed by magnetic resonance. The time course of ammonia levels in brain, muscle, blood, and urine; of glutamine, lactate, and water content in brain; of glomerular filtration rate and kidney damage; and of hepatic encephalopathy (HE) and intracranial pressure was assessed. ALF reduces kidney glomerular filtration rate (GFR) as reflected by reduced inulin clearance. GFR reduction is due to both reduced renal perfusion and kidney tubular damage as reflected by increased Kim-1 in urine and histological analysis. Blocking NMDA receptors delays kidney damage, allowing transient increased GFR and ammonia elimination which delays hyperammonemia and associated changes in brain. Blocking NMDA receptors does not prevent cerebral edema or blood-brain barrier permeability but reduces or prevents changes in cerebral blood flow and brain lactate. The data show that dual protective effects of MK-801 in kidney and brain delay cerebral alterations, HE, intracranial pressure increase and death. NMDA receptors antagonists may increase survival of patients with ALF by providing additional time for liver transplantation or regeneration. PMID:24338618

  20. Prostate stem cell antigen is an endogenous lynx1-like prototoxin that antagonizes alpha7 containing nicotinic receptors and prevents programmed cell death of parasympathetic neurons

    PubMed Central

    Hruska, Martin; Keefe, Julie; Wert, David; Tekinay, Ayse Begum; Hulce, Jonathan J.; Ibanez-Tallon, Ines; Nishi, Rae

    2010-01-01

    Vertebrate α–bungarotoxin-like molecules of the Ly-6 super family have been implicated as balancers of activity and survival in the adult nervous system. To determine whether a member of this family could be involved in the development of the avian ciliary ganglion, we identified 6 Gallus genes by their homology in structure to mouse lynx1 and lynx2. One of these genes, an ortholog of prostate stem cell antigen (PSCA), is barely detectable at embryonic day 8, prior to neuronal cell loss in the ciliary ganglion, but increases over 100-fold as the number of neurons begins to decline between E9 and E14. PSCA is highly expressed in chicken and mouse telencephalon and peripheral ganglia and correlates with expression of α7-containing nicotinic acetylcholine receptors (α7-nAChRs). Misexpressing PSCA prior to cell death in the ciliary ganglion blocks α7-nAChR activation by nicotine and rescues the choroid subpopulation from dying. Thus, PSCA, a molecule previously identified as a marker of prostate cancer, is a member of the Ly-6 neurotoxin-like family in the nervous system, and is likely to play a role as a modulator of α7 signaling induced cell death during development. PMID:19940180

  1. Butanol extract of Ecklonia cava prevents production and aggregation of beta-amyloid, and reduces beta-amyloid mediated neuronal death.

    PubMed

    Kang, Il-Jun; Jeon, Young Eun; Yin, Xing Fu; Nam, Jin-Sik; You, Sang Guan; Hong, Myo Soon; Jang, Bong Geom; Kim, Min-Ju

    2011-09-01

    Beta-amyloid (Aβ) is a major pathogenic peptide for Alzheimer's disease (AD) and is generated by the processing of amyloid precursor protein (APP). The Aβ monomers aggregate into oligomeric and fibrillar forms which have been implicated as the toxic species inducing the neuronal dysfunction. Brown algae Ecklonia cava is known for its anti-oxidant and anti-inflammatory functions. Therefore, we tested the effect of E. cava extract on the production and aggregation of Aβ peptides. The butanol extract of E. cava reduced Aβ secretion from HEK293 cells expressing APP with Swedish mutation and increased soluble APPα and C-terminal fragment-α (CTFα), of which activity was similar to BACE (β-site of APP cleaving enzyme) inhibitors. Furthermore, the extract inhibited Aβ oligomerization, particularly mid-size oligomer formation, confirmed by the ultrastructural morphology. Congo red, thioflavin T assays, and electron microscopy showed that the extract inhibited Aβ fibril formation effectively. Finally, the extract protected primary cortical neurons from various Aβ-induced cell deaths, especially oligomer-induced death. Although further study is needed to test the effectiveness of the extract in vivo, our results demonstrate, for the first time, that the butanol extract of E. cava could be used as an anti-Aβ agent for AD therapeutics. PMID:21693162

  2. On involvement of transcription factors nuclear factor kappa-light-chain-enhancer of activated B cells, activator protein-1 and signal transducer and activator of transcription-3 in photodynamic therapy-induced death of crayfish neurons and satellite glial cells.

    PubMed

    Berezhnaya, Elena; Neginskaya, Marya; Kovaleva, Vera; Sharifulina, Svetlana; Ischenko, Irina; Komandirov, Maxim; Rudkovskii, Mikhail; Uzdensky, Anatoly B

    2015-07-01

    Photodynamic therapy (PDT) is currently used in the treatment of brain tumors. However, not only malignant cells but also neighboring normal neurons and glial cells are damaged during PDT. In order to study the potential role of transcription factors-nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), activator protein (AP-1), and signal transducer and activator of transcription-3 (STAT-3)-in photodynamic injury of normal neurons and glia, we photosensitized the isolated crayfish mechanoreceptor consisting of a single sensory neuron enveloped by glial cells. Application of different inhibitors and activators showed that transcription factors NF-κB (inhibitors caffeic acid phenethyl ester and parthenolide, activator betulinic acid), AP-1 (inhibitor SR11302), and STAT-3 (inhibitors stattic and cucurbitacine) influenced PDT-induced death and survival of neurons and glial cells in different ways. These experiments indicated involvement of NF-κB in PDT-induced necrosis of neurons and apoptosis of glial cells. However, in glial cells, it played the antinecrotic role. AP-1 was not involved in PDT-induced necrosis of neurons and glia, but mediated glial apoptosis. STAT-3 was involved in PDT-induced apoptosis of glial cells and necrosis of neurons and glia. Therefore, signaling pathways that regulate cell death and survival in neurons and glial cells are different. Using various inhibitors or activators of transcription factors, one can differently influence the sensitivity and resistance of neurons and glial cells to PDT. PMID:26160345

  3. On involvement of transcription factors nuclear factor kappa-light-chain-enhancer of activated B cells, activator protein-1 and signal transducer and activator of transcription-3 in photodynamic therapy-induced death of crayfish neurons and satellite glial cells

    NASA Astrophysics Data System (ADS)

    Berezhnaya, Elena; Neginskaya, Marya; Kovaleva, Vera; Sharifulina, Svetlana; Ischenko, Irina; Komandirov, Maxim; Rudkovskii, Mikhail; Uzdensky, Anatoly B.

    2015-07-01

    Photodynamic therapy (PDT) is currently used in the treatment of brain tumors. However, not only malignant cells but also neighboring normal neurons and glial cells are damaged during PDT. In order to study the potential role of transcription factors-nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), activator protein (AP-1), and signal transducer and activator of transcription-3 (STAT-3)-in photodynamic injury of normal neurons and glia, we photosensitized the isolated crayfish mechanoreceptor consisting of a single sensory neuron enveloped by glial cells. Application of different inhibitors and activators showed that transcription factors NF-κB (inhibitors caffeic acid phenethyl ester and parthenolide, activator betulinic acid), AP-1 (inhibitor SR11302), and STAT-3 (inhibitors stattic and cucurbitacine) influenced PDT-induced death and survival of neurons and glial cells in different ways. These experiments indicated involvement of NF-κB in PDT-induced necrosis of neurons and apoptosis of glial cells. However, in glial cells, it played the antinecrotic role. AP-1 was not involved in PDT-induced necrosis of neurons and glia, but mediated glial apoptosis. STAT-3 was involved in PDT-induced apoptosis of glial cells and necrosis of neurons and glia. Therefore, signaling pathways that regulate cell death and survival in neurons and glial cells are different. Using various inhibitors or activators of transcription factors, one can differently influence the sensitivity and resistance of neurons and glial cells to PDT.

  4. Prognostic indicators of adverse renal outcome and death in acute kidney injury hospital survivors

    PubMed Central

    Hamzić-Mehmedbašić, Aida; Rašić, Senija; Balavac, Merima; Rebić, Damir; Delić-Šarac, Marina; Durak-Nalbantić, Azra

    2016-01-01

    Introduction: Data regarding prognostic factors of post-discharge mortality and adverse renal function outcome in acute kidney injury (AKI) hospital survivors are scarce and controversial. Objectives: We aimed to identify predictors of post-discharge mortality and adverse renal function outcome in AKI hospital survivors. Patients and Methods: The study group consisted of 84 AKI hospital survivors admitted to the tertiary medical center during 2-year period. Baseline clinical parameters, with renal outcome 3 months after discharge and 6-month mortality were evaluated. According survival and renal function outcome, patients were divided into two groups. Results: Patients who did not recover renal function were statistically significantly older (P < 0.007) with higher Charlson comorbidity index (CCI) score (P < 0.000) and more likely to have anuria and oliguria (P = 0.008) compared to those with recovery. Deceased AKI patients were statistically significantly older (P < 0.000), with higher CCI score (P < 0.000), greater prevalence of sepsis (P =0.004), higher levels of C-reactive protein (CRP) (P < 0.017) and ferritin (P < 0.051) and lower concentrations of albumin (P<0.01) compared to survivors. By multivariate analysis, independent predictors of adverse renal outcome were female gender (P =0.033), increasing CCI (P =0.000), presence of pre-existing chronic kidney disease (P =0.000) and diabetes mellitus (P =0.019) as well as acute decompensated heart failure (ADHF) (P =0.032), while protective factor for renal function outcome was higher urine output (P =0.009). Independent predictors of post-discharge mortality were female gender (P =0.04), higher CCI score (P =0.001) and sepsis (P =0.034). Conclusion: Female AKI hospital survivors with increasing burden of comorbidities, diagnosis of sepsis and ADHF seem to be at high-risk for poor post-discharge outcome. PMID:27471736

  5. Disrupted axon-glia interactions at the paranode in myelinated nerves cause axonal degeneration and neuronal cell death in the aged Caspr mutant mouse shambling.

    PubMed

    Takagishi, Yoshiko; Katanosaka, Kimiaki; Mizoguchi, Hiroyuki; Murata, Yoshiharu

    2016-07-01

    Emerging evidence suggests that axonal degeneration is a disease mechanism in various neurodegenerative diseases and that the paranodes at the nodes of Ranvier may be the initial site of pathogenesis. We investigated the pathophysiology of the disease process in the central and peripheral nervous systems of a Caspr mutant mouse, shambling (shm), which is affected by disrupted paranodal structures and impaired nerve conduction of myelinated nerves. The shm mice manifest a progressive neurological phenotype as mice age. We found extensive axonal degeneration and a loss of neurons in the central nervous system and peripheral nervous system in aged shm mice. Axonal alteration of myelinated nerves was defined by abnormal distribution and expression of neurofilaments and derangements in the status of phosphorylated and non/de-phosphorylated neurofilaments. Autophagy-related structures were also accumulated in degenerated axons and neurons. In conclusion, our results suggest that disrupted axon-glia interactions at the paranode cause the cytoskeletal alteration in myelinated axons leading to neuronal cell death, and the process involves detrimental autophagy and aging as factors that promote the pathogenesis. PMID:27255813

  6. Protection against glucose-induced neuronal death by NAAG and GCP II inhibition is regulated by mGluR3.

    PubMed

    Berent-Spillson, Alison; Robinson, Amanda M; Golovoy, David; Slusher, Barbara; Rojas, Camilo; Russell, James W

    2004-04-01

    Glutamate carboxypeptidase II (GCP II) inhibition has previously been shown to be protective against long-term neuropathy in diabetic animals. In the current study, we have determined that the GCP II inhibitor 2-(phosphonomethyl) pentanedioic acid (2-PMPA) is protective against glucose-induced programmed cell death (PCD) and neurite degeneration in dorsal root ganglion (DRG) neurons in a cell culture model of diabetic neuropathy. In this model, inhibition of caspase activation is mediated through the group II metabotropic glutamate receptor, mGluR3. 2-PMPA neuroprotection is completely reversed by the mGluR3 antagonist (S)-alpha-ethylglutamic acid (EGLU). In contrast, group I and III mGluR inhibitors have no effect on 2-PMPA neuroprotection. Furthermore, we show that two mGluR3 agonists, the direct agonist (2R,4R)-4-aminopyrrolidine-2, 4-dicarboxylate (APDC) and N-acetyl-aspartyl-glutamate (NAAG) provide protection to neurons exposed to high glucose conditions, consistent with the concept that 2-PMPA neuroprotection is mediated by increased NAAG activity. Inhibition of GCP II or mGluR3 may represent a novel mechanism to treat neuronal degeneration under high-glucose conditions. PMID:15030392

  7. Methylmercury causes neuronal cell death through the suppression of the TrkA pathway: In vitro and in vivo effects of TrkA pathway activators

    SciTech Connect

    Fujimura, Masatake; Usuki, Fusako

    2015-02-01

    Methylmercury (MeHg) is an environmental toxin which induces cell death specific for the nervous systems. Here we show that MeHg causes neuronal cell death through the suppression of the tropomyosin receptor kinase A (TrkA) pathway, and that compounds activating the TrkA pathway prevent MeHg-induced nerve damage in vitro and in vivo. We first investigated the mechanism of MeHg-induced neurotoxicity in differentiating neurons using PC12 cells. Exposure to 100 nM MeHg for 1 day induced apoptosis in differentiating PC12 cells. Further, MeHg-induced apoptosis was preceded by inhibition of neurite extension, as determined by ELISA analyses of the neurite-specific protein neurofilament triplet H protein (NF-H). To determine the mechanism of MeHg-induced apoptosis, we evaluated the effects of MeHg on the TrkA pathway, which is known to regulate neuronal differentiation and viability. Western blot analysis demonstrated that, like the TrkA phosphorylation inhibitor K252a, MeHg inhibited phosphorylation of TrkA and its downstream effectors. Furthermore, GM1 ganglioside and its analog MCC-257, which enhance TrkA phosphorylation, overcame the effect of MeHg in neurons, supporting the involvement of the TrkA pathway in MeHg-induced nerve damage. Finally, we demonstrated that MCC-257 rescued the clinical sign and pathological changes in MeHg-exposed rats. These findings indicate that MeHg-induced apoptosis in neuron is triggered by inhibition of the TrkA pathway, and that GM1 ganglioside and MCC-257 effectively prevent MeHg-induced nerve damage. - Highlights: • Exposure to 100 nM MeHg for 1 day induced apoptosis in differentiating PC12 cells. • Inhibition of neurite extension was involved in MeHg-induced apoptosis. • Like the TrkA phosphorylation inhibitor, MeHg inhibited phosphorylation of TrkA. • GM1 ganglioside and its analog effectively prevented MeHg-induced nerve damage.

  8. Plasma ceramides predict cardiovascular death in patients with stable coronary artery disease and acute coronary syndromes beyond LDL-cholesterol

    PubMed Central

    Laaksonen, Reijo; Ekroos, Kim; Sysi-Aho, Marko; Hilvo, Mika; Vihervaara, Terhi; Kauhanen, Dimple; Suoniemi, Matti; Hurme, Reini; März, Winfried; Scharnagl, Hubert; Stojakovic, Tatjana; Vlachopoulou, Efthymia; Lokki, Marja-Liisa; Nieminen, Markku S.; Klingenberg, Roland; Matter, Christian M.; Hornemann, Thorsten; Jüni, Peter; Rodondi, Nicolas; Räber, Lorenz; Windecker, Stephan; Gencer, Baris; Pedersen, Eva Ringdal; Tell, Grethe S.; Nygård, Ottar; Mach, Francois; Sinisalo, Juha; Lüscher, Thomas F.

    2016-01-01

    Aims The aim was to study the prognostic value of plasma ceramides (Cer) as cardiovascular death (CV death) markers in three independent coronary artery disease (CAD) cohorts. Methods and results Corogene study is a prospective Finnish cohort including stable CAD patients (n = 160). Multiple lipid biomarkers and C-reactive protein were measured in addition to plasma Cer(d18:1/16:0), Cer(d18:1/18:0), Cer(d18:1/24:0), and Cer(d18:1/24:1). Subsequently, the association between high-risk ceramides and CV mortality was investigated in the prospective Special Program University Medicine—Inflammation in Acute Coronary Syndromes (SPUM-ACS) cohort (n = 1637), conducted in four Swiss university hospitals. Finally, the results were validated in Bergen Coronary Angiography Cohort (BECAC), a prospective Norwegian cohort study of stable CAD patients. Ceramides, especially when used in ratios, were significantly associated with CV death in all studies, independent of other lipid markers and C-reactive protein. Adjusted odds ratios per standard deviation for the Cer(d18:1/16:0)/Cer(d18:1/24:0) ratio were 4.49 (95% CI, 2.24–8.98), 1.64 (1.29–2.08), and 1.77 (1.41–2.23) in the Corogene, SPUM-ACS, and BECAC studies, respectively. The Cer(d18:1/16:0)/Cer(d18:1/24:0) ratio improved the predictive value of the GRACE score (net reclassification improvement, NRI = 0.17 and ΔAUC = 0.09) in ACS and the predictive value of the Marschner score in stable CAD (NRI = 0.15 and ΔAUC = 0.02). Conclusions Distinct plasma ceramide ratios are significant predictors of CV death both in patients with stable CAD and ACS, over and above currently used lipid markers. This may improve the identification of high-risk patients in need of more aggressive therapeutic interventions. PMID:27125947

  9. Induction of apoptotic death and retardation of neuronal differentiation of human neural stem cells by sodium arsenite treatment

    SciTech Connect

    Ivanov, Vladimir N.; Hei, Tom K.

    2013-04-01

    Chronic arsenic toxicity is a global health problem that affects more than 100 million people worldwide. Long-term health effects of inorganic sodium arsenite in drinking water may result in skin, lung and liver cancers and in severe neurological abnormalities. We investigated in the present study whether sodium arsenite affects signaling pathways that control cell survival, proliferation and neuronal differentiation of human neural stem cells (NSC). We demonstrated that the critical signaling pathway, which was suppressed by sodium arsenite in NSC, was the protective PI3K–AKT pathway. Sodium arsenite (2–4 μM) also caused down-regulation of Nanog, one of the key transcription factors that control pluripotency and self-renewal of stem cells. Mitochondrial damage and cytochrome-c release induced by sodium arsenite exposure was followed by initiation of the mitochondrial apoptotic pathway in NSC. Beside caspase-9 and caspase-3 inhibitors, suppression of JNK activity decreased levels of arsenite-induced apoptosis in NSC. Neuronal differentiation of NSC was substantially inhibited by sodium arsenite exposure. Overactivation of JNK1 and ERK1/2 and down-regulation of PI3K–AKT activity induced by sodium arsenite were critical factors that strongly affected neuronal differentiation. In conclusion, sodium arsenite exposure of human NSC induces the mitochondrial apoptotic pathway, which is substantially accelerated due to the simultaneous suppression of PI3K–AKT. Sodium arsenite also negatively affects neuronal differentiation of NSC through overactivation of MEK–ERK and suppression of PI3K–AKT. - Highlights: ► Arsenite induces the mitochondrial apoptotic pathway in human neural stem cells. ► Arsenite-induced apoptosis is strongly upregulated by suppression of PI3K–AKT. ► Arsenite-induced apoptosis is strongly down-regulated by inhibition of JNK–cJun. ► Arsenite negatively affects neuronal differentiation by inhibition of PI3K–AKT.

  10. Impairment of enzymatic antioxidant defenses is associated with bilirubin-induced neuronal cell death in the cerebellum of Ugt1 KO mice

    PubMed Central

    Bortolussi, G; Codarin, E; Antoniali, G; Vascotto, C; Vodret, S; Arena, S; Cesaratto, L; Scaloni, A; Tell, G; Muro, A F

    2015-01-01

    Severe hyperbilirubinemia is toxic during central nervous system development. Prolonged and uncontrolled high levels of unconjugated bilirubin lead to bilirubin-induced encephalopathy and eventually death by kernicterus. Despite extensive studies, the molecular and cellular mechanisms of bilirubin toxicity are still poorly defined. To fill this gap, we investigated the molecular processes underlying neuronal injury in a mouse model of severe neonatal jaundice, which develops hyperbilirubinemia as a consequence of a null mutation in the Ugt1 gene. These mutant mice show cerebellar abnormalities and hypoplasia, neuronal cell death and die shortly after birth because of bilirubin neurotoxicity. To identify protein changes associated with bilirubin-induced cell death, we performed proteomic analysis of cerebella from Ugt1 mutant and wild-type mice. Proteomic data pointed-out to oxidoreductase activities or antioxidant processes as important intracellular mechanisms altered during bilirubin-induced neurotoxicity. In particular, they revealed that down-representation of DJ-1, superoxide dismutase, peroxiredoxins 2 and 6 was associated with hyperbilirubinemia in the cerebellum of mutant mice. Interestingly, the reduction in protein levels seems to result from post-translational mechanisms because we did not detect significant quantitative differences in the corresponding mRNAs. We also observed an increase in neuro-specific enolase 2 both in the cerebellum and in the serum of mutant mice, supporting its potential use as a biomarker of bilirubin-induced neurological damage. In conclusion, our data show that different protective mechanisms fail to contrast oxidative burst in bilirubin-affected brain regions, ultimately leading to neurodegeneration. PMID:25950469

  11. Right ventricular dysfunction: an independent and incremental predictor of cardiac deaths late after acute myocardial infarction.

    PubMed

    Di Bella, Gianluca; Siciliano, Valeria; Aquaro, Giovanni D; De Marchi, Daniele; Rovai, Daniele; Carerj, Scipione; Molinaro, Sabrina; Lombardi, Massimo; Pingitore, Alessandro

    2015-02-01

    Prognostic implication of right ventricular dysfunction and infarction scar in the chronic phase of the myocardial infarction has been little analyzed. In 299 consecutive patients (age 63 ± 11 years) with >3 months old myocardial infarction, we quantified right and left ventricular volumes and ejection fractions by cine cardiac magnetic resonance, and right and left ventricular scar tissue by late gadolinium enhancement. During follow-up (median, 2.4 years) cardiac events (cardiac-related deaths or appropriate intra-cardiac defibrillator shocks) occurred in 21 patients. Right ventricular systolic dysfunction (ejection fraction lower the reference mean values-2 SD) was present in 67 patients (22 %), right ventricular late gadolinium enhancement was observed in 15 patients (5 %). After adjustment for left ventricular end-diastolic volume, wall motion score index, and global extent of late gadolinium enhancement, right ventricular dysfunction was an independent and incremental predictor of cardiac events (p = 0.0053), while right ventricular scar tissue extent was not. Right ventricular dysfunction is an independent and incremental predictor of cardiac events also in the chronic phase of the myocardial infarction. In these patients, right ventricular dysfunction does not necessarily mean right ventricular infarction scar, but likely reflects the effects of hemodynamic and biohumoral factors. PMID:25348657

  12. Liver-Specific Deletion of SRSF2 Caused Acute Liver Failure and Early Death in Mice.

    PubMed

    Cheng, Yuanming; Luo, Chunling; Wu, Wenwu; Xie, Zhiqin; Fu, Xiangdong; Feng, Ying

    2016-06-01

    The liver performs a variety of unique functions critical for metabolic homeostasis. Here, we show that mice lacking the splicing factor SRSF2 but not SRSF1 in hepatocytes have severe liver pathology and biochemical abnormalities. Histological analyses revealed generalized hepatitis with the presence of ballooned hepatocytes and evidence of fibrosis. Molecular analysis demonstrated that SRSF2 governs splicing of multiple genes involved in the stress-induced cell death pathway in the liver. More importantly, SRSF2 also functions as a potent transcription activator, required for efficient expression of transcription factors mainly responsible for energy homeostasis and bile acid metabolism in the liver. Consistent with the effects of SRSF2 in gene regulation, accumulation of total cholesterol and bile acids was prominently observed in the mutant liver, followed by enhanced generation of reactive oxygen species and increased endoplasmic reticulum stress, as revealed by biochemical and ultrastructural analyses. Taking these observations together, inactivation of SRSF2 in liver caused dysregulated splicing events and hepatic metabolic disorders, which trigger endoplasmic reticulum stress, oxidative stress, and finally liver failure. PMID:27022105

  13. 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

  14. 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

  15. Amyloid beta-peptide impairs ion-motive ATPase activities: evidence for a role in loss of neuronal Ca2+ homeostasis and cell death.

    PubMed

    Mark, R J; Hensley, K; Butterfield, D A; Mattson, M P

    1995-09-01

    The amyloid beta-peptide (A beta) that accumulates as insoluble plaques in the brain in Alzheimer's disease can be directly neurotoxic and can increase neuronal vulnerability to excitotoxic insults. The mechanism of A beta toxicity is unclear but is believed to involve generation of reactive oxygen species (ROS) and loss of calcium homeostasis. We now report that exposure of cultured rat hippocampal neurons to A beta 1-40 or A beta 25-35 causes a selective reduction in Na+/K(+)-ATPase activity which precedes loss of calcium homeostasis and cell degeneration. Na+/K(+)-ATPase activity was reduced within 30 min of exposure to A beta 25-35 and declined to less than 40% of basal level by 3 hr. A beta did not impair other Mg(2+)-dependent ATPase activities or Na+/Ca2+ exchange. Experiments with ouabain, a specific inhibitor of the Na+/K(+)-ATPase, demonstrated that impairment of this enzyme was sufficient to induce an elevation of [Ca2+]i and neuronal injury. Impairment of Na+/K(+)-ATPase activity appeared to be causally involved in the elevation of [Ca2+]i and neurotoxicity since suppression of Na+ influx significantly reduced A beta- and ouabain-induced [Ca2+]i elevation and neuronal death. Neuronal degeneration induced by ouabain appeared to be of an apoptotic form as indicated by nuclear condensation and DNA fragmentation. The antioxidant free radical scavengers vitamin E and propylgallate significantly attenuated A beta-induced impairment of Na+/K(+)-ATPase activity, elevation of [Ca2+]i and neurotoxicity, suggesting a role for ROS. Finally, exposure of synaptosomes from postmortem human hippocampus to A beta resulted in a significant and specific reduction in Na+/K(+)-ATPase and Ca(2+)-ATPase activities, without affecting other Mg(2+)-dependent ATPase activities or Na+/Ca2+ exchange. These data suggest that impairment of ion-motive ATPases may play a role in the pathogenesis of neuronal injury in Alzheimer's disease. PMID:7666206

  16. 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

  17. 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

  18. Matrix Metalloproteinase-9 Regulates Neuronal Circuit Development and Excitability.

    PubMed

    Murase, Sachiko; Lantz, Crystal L; Kim, Eunyoung; Gupta, Nitin; Higgins, Richard; Stopfer, Mark; Hoffman, Dax A; Quinlan, Elizabeth M

    2016-07-01

    In early postnatal development, naturally occurring cell death, dendritic outgrowth, and synaptogenesis sculpt neuronal ensembles into functional neuronal circuits. Here, we demonstrate that deletion of the extracellular proteinase matrix metalloproteinase-9 (MMP-9) affects each of these processes, resulting in maladapted neuronal circuitry. MMP-9 deletion increases the number of CA1 pyramidal neurons but decreases dendritic length and complexity. Parallel changes in neuronal morphology are observed in primary visual cortex and persist into adulthood. Individual CA1 neurons in MMP-9(-/-) mice have enhanced input resistance and a significant increase in the frequency, but not amplitude, of miniature excitatory postsynaptic currents (mEPSCs). Additionally, deletion of MMP-9 significantly increases spontaneous neuronal activity in awake MMP-9(-/-) mice and enhances response to acute challenge by the excitotoxin kainate. Our data document a novel role for MMP-9-dependent proteolysis: the regulation of several aspects of circuit maturation to constrain excitability throughout life. PMID:26093382

  19. Matrix Metalloproteinase-9 regulates neuronal circuit development and excitability

    PubMed Central

    Murase, Sachiko; Lantz, Crystal; Kim, Eunyoung; Gupta, Nitin; Higgins, Richard; Stopfer, Mark; Hoffman, Dax A.; Quinlan, Elizabeth M.

    2015-01-01

    In early postnatal development, naturally occurring cell death, dendritic outgrowth and synaptogenesis sculpt neuronal ensembles into functional neuronal circuits. Here we demonstrate that deletion of the extracellular proteinase MMP-9 affects each of these processes, resulting in maladapted neuronal circuitry. MMP-9 deletion increases the number of CA1 pyramidal neurons, but decreases dendritic length and complexity while dendritic spine density is unchanged. Parallel changes in neuronal morphology are observed in primary visual cortex, and persist into adulthood. Individual CA1 neurons in MMP-9−/− mice have enhanced input resistance and a significant increase in the frequency, but not amplitude, of miniature excitatory postsynaptic currents (mEPSCs). Additionally, deletion of MMP-9 significant increases spontaneous neuronal activity in awake MMP-9−/− mice and enhances response to acute challenge by the excitotoxin kainate. Thus MMP-9-dependent proteolysis regulates several aspects of circuit maturation to constrain excitability throughout life. PMID:26093382

  20. Involvement of the mitochondrial apoptotic pathway and nitric oxide synthase in dopaminergic neuronal death induced by 6-hydroxydopamine and lipopolysaccharide.

    PubMed

    Singh, Sarika; Kumar, Sachin; Dikshit, Madhu

    2010-01-01

    The primary pathology in Parkinson's disease patients is significant loss of dopaminergic neurons in the substantia nigra through multiple mechanisms. We previously have demonstrated the involvement of nitric oxide (NO) in the dopaminergic neurodegeneration induced by 6-hydroxydopamine (6-OHDA) and lipopolysaccharide (LPS) in rats. The present study was undertaken to investigate further the role of NO in the mitochondria-mediated apoptosis of dopaminergic neurons during the early time period after administration of 6-OHDA and LPS. Measurement of dopamine and its metabolites, TH immunolabeling, cytochrome-c release, mitochondrial complex-I and caspase-3 activity assessment was performed in both the 6-OHDA- and LPS-induced experimental models of Parkinson's disease. Significant decreases in dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), tyrosine hydroxylase (TH) immunolabeling and mitochondrial complex-I activity were observed, with increase in cytochrome-c release and caspase-3 activation. Dopmaine and its metabolite levels, mitochondrial complex-I activity and caspase-3 activity were significantly reversed with treatment of the NOS inhibitor, L-NAME. The reduction in the extent of cytochrome-c release responded variably to NOS inhibition in both the models. The results obtained suggest that NO contributes to mitochondria-mediated neuronal apoptosis in the dopaminergic neurodegeneration induced by 6-OHDA and LPS in rats. PMID:20594414

  1. 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

  2. Ablation of RIC8A function in mouse neurons leads to a severe neuromuscular phenotype and postnatal death.

    PubMed

    Ruisu, Katrin; Kask, Keiu; Meier, Riho; Saare, Merly; Raid, Raivo; Veraksitš, Alar; Karis, Alar; Tõnissoo, Tambet; Pooga, Margus

    2013-01-01

    Resistance to inhibitors of cholinesterase 8 (RIC8) is a guanine nucleotide exchange factor required for the intracellular regulation of G protein signalling. RIC8 activates different Gα subunits via non-canonical pathway, thereby amplifying and prolonging the G protein mediated signal. In order to circumvent the embryonic lethality associated with the absence of RIC8A and to study its role in the nervous system, we constructed Ric8a conditional knockout mice using Cre/loxP technology. Introduction of a synapsin I promoter driven Cre transgenic mouse strain (SynCre) into the floxed Ric8a (Ric8a (F/F) ) background ablated RIC8A function in most differentiated neuron populations. Mutant SynCre (+/-) Ric8 (lacZ/F) mice were born at expected Mendelian ratio, but they died in early postnatal age (P4-P6). The mutants exhibited major developmental defects, like growth retardation and muscular weakness, impaired coordination and balance, muscular spasms and abnormal heart beat. Histological analysis revealed that the deficiency of RIC8A in neurons caused skeletal muscle atrophy and heart muscle hypoplasia, in addition, the sinoatrial node was misplaced and its size reduced. However, we did not observe gross morphological changes in brains of SynCre (+/-) Ric8a (lacZ/F) mutants. Our results demonstrate that in mice the activity of RIC8A in neurons is essential for survival and its deficiency causes a severe neuromuscular phenotype. PMID:23977396

  3. Role of Na+-H+ and Na+-Ca2+ exchange in hypoxia-related acute astrocyte death.

    PubMed

    Bondarenko, Alexander; Svichar, Nataliya; Chesler, Mitchell

    2005-01-01

    Cultured astrocytes do not succumb to hypoxia/zero glucose for up to 24 h, yet astrocyte death following injury can occur within 1 h. It was previously demonstrated that astrocyte loss can occur quickly when the gaseous and interstitial ionic changes of transient brain ischemia are simulated: After a 20-40-min exposure to hypoxic, acidic, ion-shifted Ringer (HAIR), most cell