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Sample records for acute neuronal damage

  1. DNA Damage Induced Neuronal Death

    DTIC Science & Technology

    1999-10-01

    Experiments are proposed to examine the molecular mechanism by which mustard chemical warfare agents induce neuronal cell death . DNA damage is the...proposed underlying mechanism of mustard-induced neuronal cell death . We propose a novel research strategy to test this hypothesis by using mice with...perturbed DNA repair to explore the relationship between mustard-induced DNA damage and neuronal cell death . Initial in vitro studies (Years 1, 2 & 3

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

    PubMed

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

    2010-12-01

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

  3. Soman Increases Neuronal COX-2 Levels: Possible Link between Seizures and Protracted Neuronal Damage

    PubMed Central

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

    2010-01-01

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

  4. Target organ damage in acute heart failure.

    PubMed

    Casado Cerrada, J; Zabaleta Camino, J P; Fontecha Ortega, M

    2016-03-01

    Acute heart failure is a prognostic factor due to its high mortality during the acute phase and the increased frequency of medium to long-term adverse events. The pathophysiological mechanisms triggered during these exacerbations can persist after reaching clinical stability, remaining even after the acute episode has ended. A certain degree of neurohormonal activation, oxidative stress, apoptosis and inflammation (among other conditions) can therefore persist, resulting in organ damage, not just of the myocardium but likely the entire cardiovascular apparatus. This new insight into the persistence of harmful mechanisms that last beyond the exacerbations could be the start of a change in perspective for developing new therapeutic strategies that seek an overall control of hemodynamic and congestive changes that occur during acute decompensated heart failure and changes that remain after achieving clinical stability.

  5. 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.

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

    PubMed Central

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

    2014-01-01

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

  7. Antecedent glycemic control reduces severe hypoglycemia-induced neuronal damage in diabetic rats.

    PubMed

    Reno, Candace M; Tanoli, Tariq; Bree, Adam; Daphna-Iken, Dorit; Cui, Chen; Maloney, Susan E; Wozniak, David F; Fisher, Simon J

    2013-06-15

    Brain damage due to severe hypoglycemia occurs in insulin-treated people with diabetes. This study tests the hypothesis that chronic insulin therapy that normalizes elevated blood glucose in diabetic rats would be neuroprotective against brain damage induced by an acute episode of severe hypoglycemia. Male Sprague-Dawley rats were split into three groups: 1) control, non-diabetic; 2) STZ-diabetic; and 3) insulin-treated STZ-diabetic. After 3 wk of chronic treatment, unrestrained awake rats underwent acute hyperinsulinemic severe hypoglycemic (10-15 mg/dl) clamps for 1 h. Rats were subsequently analyzed for brain damage and cognitive function. Severe hypoglycemia induced 15-fold more neuronal damage in STZ-diabetic rats compared with nondiabetic rats. Chronic insulin treatment of diabetic rats, which nearly normalized glucose levels, markedly reduced neuronal damage induced by severe hypoglycemia. Fortunately, no cognitive defects associated with the hypoglycemia-induced brain damage were observed in any group. In conclusion, antecedent blood glucose control represents a major modifiable therapeutic intervention that can afford diabetic subjects neuroprotection against severe hypoglycemia-induced brain damage.

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

    PubMed Central

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

    2016-01-01

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

  9. DNA damage, neuronal and glial cell death and neurodegeneration.

    PubMed

    Barzilai, Ari

    2010-11-01

    The DNA damage response (DDR) is a key factor in the maintenance of genome stability. As such, it is a central axis in sustaining cellular homeostasis in a variety of contexts: development, growth, differentiation, and maintenance of the normal life cycle of the cell. It is now clear that diverse mechanisms encompassing cell cycle regulation, repair pathways, many aspects of cellular metabolism, and cell death are inter-linked and act in concert in response to DNA damage. Defects in the DDR in proliferating cells can lead to cancer, while DDR defects in neurons may result in neurodegeneration. Mature neurons are highly differentiated, post-mitotic cells that cannot be replenished after disease or trauma. Their high metabolic activity generates large amounts of reactive oxygen species with DNA damaging capacity. Moreover, their intense transcriptional activity increases the potential for genomic DNA damage. Respectively, neurons have elaborate mechanisms to defend the integrity of their genome, thus ensuring their longevity and functionality in the face of these threats. Over the course of the past two decades, there has been a substantial increase in our understanding of the role of glial cells in supporting the neuronal cell DDR and longevity. This review article focuses on the potential role of the DDR in the etiology and pathogenesis of neurodegenerative diseases, and in addition, it describes various aspects of glial cell functionality in two genomic instability disorders: ataxia telangiectasia (A-T) and Nijmegen breakage syndrome.

  10. Narratives and Neurons: Stories of Damaged Brains

    PubMed Central

    Mickley, G. Andrew; Hoyt, Daniel A.

    2010-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  12. Alphavirus Encephalomyelitis: Mechanisms and Approaches to Prevention of Neuronal Damage.

    PubMed

    Griffin, Diane E

    2016-07-01

    Mosquito-borne viruses are important causes of death and long-term neurologic disability due to encephalomyelitis. Studies of mice infected with the alphavirus Sindbis virus have shown that outcome is dependent on the age and genetic background of the mouse and virulence of the infecting virus. Age-dependent susceptibility reflects the acquisition by neurons of resistance to virus replication and virus-induced cell death with maturation. In mature mice, the populations of neurons most susceptible to infection are in the hippocampus and anterior horn of the spinal cord. Hippocampal infection leads to long-term memory deficits in mice that survive, while motor neuron infection can lead to paralysis and death. Neuronal death is immune-mediated, rather than a direct consequence of virus infection, and associated with entry and differentiation of pathogenic T helper 17 cells in the nervous system. To modulate glutamate excitotoxicity, mice were treated with an N-methyl-D-aspartate receptor antagonist, α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor antagonists or a glutamine antagonist. The N-methyl-D-aspartate receptor antagonist MK-801 protected hippocampal neurons but not motor neurons, and mice still became paralyzed and died. α-Amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor antagonists GYKI-52466 and talampanel protected both hippocampal and motor neurons and prevented paralysis and death. Glutamine antagonist 6-diazo-5-l-norleucine protected hippocampal neurons and improved memory generation in mice surviving infection with an avirulent virus. Surprisingly, in all cases protection was associated with inhibition of the antiviral immune response, reduced entry of inflammatory cells into the central nervous system, and delayed virus clearance, emphasizing the importance of treatment approaches that include prevention of immunopathologic damage.

  13. Damage of hippocampal neurons in rats with chronic alcoholism

    PubMed Central

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

    2014-01-01

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

  14. Entamoeba histolytica infection and secreted proteins proteolytically damage enteric neurons.

    PubMed

    Lourenssen, Sandra; Houpt, Eric R; Chadee, Kris; Blennerhassett, Michael G

    2010-12-01

    The enteric protozoan parasite Entamoeba histolytica causes amebic colitis through disruption of the mucus layer, followed by binding to and destruction of epithelial cells. However, it is not known whether ameba infections or ameba components can directly affect the enteric nervous system. Analysis of mucosal innervations in the mouse model of cecal amebiasis showed that axon density was diminished to less than 25% of control. To determine whether amebas directly contributed to axon loss, we tested the effect of either E. histolytica secreted products (Eh-SEC) or soluble components (Eh-SOL) to an established coculture model of myenteric neurons, glia, and smooth muscle cells. Neuronal survival and axonal degeneration were measured after 48 h of exposure to graded doses of Eh-SEC or Eh-SOL (10 to 80 μg/ml). The addition of 80 μg of either component/ml decreased the neuron number by 30%, whereas the axon number was decreased by 50%. Cytotoxicity was specific to the neuronal population, since the glial and smooth muscle cell number remained similar to that of the control, and was completely abrogated by prior heat denaturation. Neuronal damage was partially prevented by the cysteine protease inhibitor E-64, showing that a heat-labile protease was involved. E. histolytica lysates derived from amebas deficient in the major secreted protease EhCP5 caused a neurotoxicity similar to that of wild-type amebas. We conclude that E. histolytica infection and ameba protease activity can cause selective damage to enteric neurons.

  15. Rat MYH, a glycosylase for repair of oxidatively damaged DNA, has brain-specific isoforms that localize to neuronal mitochondria.

    PubMed

    Englander, Ella W; Hu, Zhaoyong; Sharma, Abha; Lee, Heung-Man; Wu, Zhao-Hui; Greeley, George H

    2002-12-01

    Mitochondrial genomes are exposed to a heavy load of reactive oxygen species (ROS) that damage DNA. Since in neurons, mitochondrial DNA integrity must be maintained over the entire mammalian life span, neuronal mitochondria most likely repair oxidatively damaged DNA. We show that the Escherichia coli MutY DNA glycosylase homolog (MYH) in rat (rMYH) involved in repair of oxidative damage is abundantly expressed in the rat brain, with isoforms that are exclusive to brain tissue. Confocal microscopy and western analyses reveal localization of rMYH in neuronal mitochondria. To assess involvement of MYH in the neuronal response to oxidative DNA damage, we used a rat model of respiratory hypoxia, in which acutely reduced blood oxygenation leads to generation of superoxide, and formation and subsequent removal of 8-hydroxy-2'-deoxyguanosine (8OHdG). Removal of 8OHdG is accompanied by a spatial increase in rMYH immunoreactivity in the brain and an increase in levels of one of the three mitochondrial MYH isoforms, suggesting that inducible and non-inducible MYH isoforms exist in the brain. The mitochondrial localization of oxidative DNA damage repair enzymes in neurons may represent a specialized neuronal mechanism that safeguards mitochondrial genomes in the face of routine and accidental exposures to heavy loads of injurious ROS.

  16. Myelin basic protein induces neuron-specific toxicity by directly damaging the neuronal plasma membrane.

    PubMed

    Zhang, Jie; Sun, Xin; Zheng, Sixin; Liu, Xiao; Jin, Jinghua; Ren, Yi; Luo, Jianhong

    2014-01-01

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

  17. A novel perspective on neuron study: damaging and promoting effects in different neurons induced by mechanical stress.

    PubMed

    Wang, Yazhou; Wang, Wei; Li, Zong; Hao, Shilei; Wang, Bochu

    2016-10-01

    A growing volume of experimental evidence demonstrates that mechanical stress plays a significant role in growth, proliferation, apoptosis, gene expression, electrophysiological properties and many other aspects of neurons. In this review, first, the mechanical microenvironment and properties of neurons under in vivo conditions are introduced and analyzed. Second, research works in recent decades on the effects of different mechanical forces, especially compression and tension, on various neurons, including dorsal root ganglion neurons, retinal ganglion cells, cerebral cortex neurons, hippocampus neurons, neural stem cells, and other neurons, are summarized. Previous research results demonstrate that mechanical stress can not only injure neurons by damaging their morphology, impacting their electrophysiological characteristics and gene expression, but also promote neuron self-repair. Finally, some future perspectives in neuron research are discussed.

  18. Reversible recovery of neuronal structures depends on the degree of neuronal damage after global cerebral ischemia in mice.

    PubMed

    Zhu, Lirui; Wang, Lei; Ju, Furong; Khan, Akbar; Cheng, Xiaofeng; Zhang, Shengxiang

    2017-03-01

    It has been observed by in vivo imaging that damaged neuronal structures can be reversibly restored after ischemic insults with the application of timely therapeutic interventions. However, what degree of neuronal damage can be restored and the time frame for reversible recovery of neuronal structures remain unclear. Here, transcranial two-photon imaging, histological staining and electron microscopy were used to investigate the reversible recovery of neuronal structures from dendrites to soma after different durations of global cerebral ischemia in mice. Intravital imaging revealed that the damage to dendritic structures was reversible when ischemia time was <1h, but they became difficult to restore after >3h of ischemia. Data from fixed YFP brain slice and Golgi staining indicated that the damage of dendritic structures progressively extended to deeper dendritic shafts with the extension of ischemia time. Furthermore, longer duration of ischemia caused an increasing number of degenerating neurons. Importantly, significant chromatin margination and karyopyknosis of neuron were observed after 6h of ischemia. These data suggested that neuronal structures could be reversibly restored when ischemia time was <1h, but irreversible and progressive damage to neurons occurred with longer duration of ischemia. Consistently, behavioral performance of post-ischemic animals experienced an ischemia time-dependent recovery. Taken together, our data suggested that recovery of neuronal structures following ischemia was dependent on the duration of ischemia, and prevention of neuronal loss is a key target for therapeutic interventions in ischemic stroke.

  19. 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

  20. Protective effects of curcumin on amyloid-β-induced neuronal oxidative damage.

    PubMed

    Huang, Han-Chang; Chang, Ping; Dai, Xue-Ling; Jiang, Zhao-Feng

    2012-07-01

    To investigate the protective effects of curcumin against amyloid-β (Aβ)-induced neuronal damage. Primary rat cortical neurons were cultured with different treatments of Aβ and curcumin. Neuronal morphologies, viability and damage were assessed. Neuronal oxidative stress was assessed, including extracellular hydrogen peroxide and intracellular reactive oxygen species. The abilities of curcumin to scavenge free radicals and to inhibit Aβ aggregation and β-sheeted formation are further assessed and discussed. Curcumin preserves cell viability, which is decreased by Aβ. The results of changed morphology, released Lactate dehydrogenases and cell viability assays indicate that curcumin protects Aβ-induced neuronal damage. Curcumin depresses Aβ-induced up-regulation of neuronal oxidative stress. The treatment sequence impacts the protective effect of curcumin on Aβ-induced neuronal damage. Curcumin shows a more protective effect on neuronal oxidative damage when curcumin was added into cultured neurons not later than Aβ, especially prior to Aβ. The abilities of curcumin to scavenge free radicals and to inhibit the formation of β-sheeted aggregation are both beneficial to depress Aβ-induced oxidative damage. Curcumin prevents neurons from Aβ-induced oxidative damage, implying the therapeutic usage for the treatment of Alzheimer's disease patients.

  1. 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

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

    SciTech Connect

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

    2007-03-15

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

  3. Mitochondrial DNA damage: molecular marker of vulnerable nigral neurons in Parkinson's disease.

    PubMed

    Sanders, Laurie H; McCoy, Jennifer; Hu, Xiaoping; Mastroberardino, Pier G; Dickinson, Bryan C; Chang, Christopher J; Chu, Charleen T; Van Houten, Bennett; Greenamyre, J T

    2014-10-01

    DNA damage can cause (and result from) oxidative stress and mitochondrial impairment, both of which are implicated in the pathogenesis of Parkinson's disease (PD). We therefore examined the role of mitochondrial DNA (mtDNA) damage in human postmortem brain tissue and in in vivo and in vitro models of PD, using a newly adapted histochemical assay for abasic sites and a quantitative polymerase chain reaction (QPCR)-based assay. We identified the molecular identity of mtDNA damage to be apurinic/apyrimidinic (abasic) sites in substantia nigra dopamine neurons, but not in cortical neurons from postmortem PD specimens. To model the systemic mitochondrial impairment of PD, rats were exposed to the pesticide rotenone. After rotenone treatment that does not cause neurodegeneration, abasic sites were visualized in nigral neurons, but not in cortex. Using a QPCR-based assay, a single rotenone dose induced mtDNA damage in midbrain neurons, but not in cortical neurons; similar results were obtained in vitro in cultured neurons. Importantly, these results indicate that mtDNA damage is detectable prior to any signs of degeneration - and is produced selectively in midbrain neurons under conditions of mitochondrial impairment. The selective vulnerability of midbrain neurons to mtDNA damage was not due to differential effects of rotenone on complex I since rotenone suppressed respiration equally in midbrain and cortical neurons. However, in response to complex I inhibition, midbrain neurons produced more mitochondrial H2O2 than cortical neurons. We report selective mtDNA damage as a molecular marker of vulnerable nigral neurons in PD and suggest that this may result from intrinsic differences in how these neurons respond to complex I defects. Further, the persistence of abasic sites suggests an ineffective base excision repair response in PD.

  4. Contribution of NMDA and non-NMDA receptors to in vivo glutamate-induced calpain activation in the rat striatum. Relation to neuronal damage.

    PubMed

    Del Río, Perla; Montiel, Teresa; Massieu, Lourdes

    2008-08-01

    Glutamate, the major excitatory neurotransmitter, can cause the death of neurons by a mechanism known as excitotoxicity. This is a calcium-dependent process and activation of the NMDA receptor subtype contributes mainly to neuronal damage, due to its high permeability to calcium. Activation of calpain, a calcium-dependent cysteine protease, has been implicated in necrotic excitotoxic neuronal death. We have investigated the contribution of NMDA and non-NMDA ionotropic receptors to calpain activation and neuronal death induced by the acute administration of glutamate into the rat striatum. Calpain activity was assessed by the cleavage of the cytoskeletal protein, alpha-spectrin. Caspase-3 activity was also studied because glutamate can also lead to apoptosis. Results show no caspase-3 activity, but a strong calpain activation involving both NMDA and non-NMDA receptors. Although neuronal damage is mediated mainly by the NMDA receptor subtype, it can not be attributed solely to calpain activity.

  5. A neuronal population in hypothalamus that dramatically resists acute ischemic injury compared to neocortex.

    PubMed

    Brisson, C Devin; Andrew, R David

    2012-07-01

    Pyramidal neurons (PyNs) of the cortex are highly susceptible to acute stroke damage, yet "lower" brain regions like hypothalamus and brain stem better survive global ischemia. Here we show for the first time that a "lower" neuron population intrinsically resists acute strokelike injury. In rat brain slices deprived of oxygen and glucose (OGD), we imaged anoxic depolarization (AD) as it propagated through neocortex or hypothalamus. AD, the initial electrophysiological event of stroke, is a front of depolarization that drains residual energy in compromised gray matter. The extent of AD reliably determines ensuing cortical damage, but do all CNS neurons generate a robust AD? During 10 min of OGD, PyNs depolarize without functional recovery. In contrast, magnocellular neuroendocrine cells (MNCs) in hypothalamus under identical stress generate a weak and delayed AD, resist complete depolarization, and rapidly repolarize when oxygen and glucose are restored. They recover their membrane potential, input resistance, and spike amplitude and can survive multiple OGD exposures. Two-photon microscopy in slices derived from a fluorescent mouse line confirms this protection, revealing PyN swelling and dendritic beading after OGD, whereas MNCs are not injured. Exposure to the Na(+)-K(+)-ATPase inhibitor ouabain (100 μM) induces AD similar to OGD in both cell types. Moreover, elevated extracellular K(+) concentration ([K(+)](o)) evokes spreading depression (SD), a milder version of AD, in PyNs but not MNCs. Therefore overriding the pump by OGD, ouabain, or elevated [K(+)](o) evokes a propagating depolarization in higher gray matter but not in MNCs. We suggest that variation in Na(+)-K(+)-ATPase pump efficiency during ischemia injury determines whether a neuronal type succumbs to or resists stroke.

  6. Acute ethanol suppresses glutamatergic neurotransmission through endocannabinoids in hippocampal neurons.

    PubMed

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

    2008-11-01

    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 post-synaptic current (mEPSC) frequencies without affecting their amplitude. This suggests that ethanol inhibits glutamate release. The CB1 receptors (CB1Rs) present on pre-synaptic 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 post-synaptic 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 post-synaptic 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.

  7. Myelin-associated glycoprotein (MAG) protects neurons from acute toxicity using a ganglioside-dependent mechanism.

    PubMed

    Mehta, Niraj R; Nguyen, Thien; Bullen, John W; Griffin, John W; Schnaar, Ronald L

    2010-03-17

    Myelin-associated glycoprotein (MAG), a protein expressed on the innermost wrap of myelin, contributes to long-term axon stability as evidenced by progressive axon degeneration in Mag-null mice. Recently, MAG was also found to protect axons from acute toxic insults. In the current study, rat dorsal root ganglion neurons were cultured on control substrata and substrata adsorbed with myelin proteins. Neurons on myelin-adsorbed surfaces were resistant to acute degeneration of neurites induced by vincristine, a cancer chemotherapeutic agent with neuropathic side effects. Myelin-mediated protection was reversed by anti-MAG antibody and was absent when cells were cultured on extracts from Mag-null mouse myelin, confirming the protective role of MAG. Gangliosides (sialylated glycosphingolipids) are one functional class of axonal receptors for MAG. In the current studies, a direct role for gangliosides in mediating the acute protective effects of MAG was established. Treatment of neurons with sialidase, an enzyme that cleaves the terminal sialic acids required for MAG binding, reversed MAG's protective effect, as did treatment with (1R,2R)-1-phenyl-2-hexadecanoylamino-3-pyrrolidino-1-propanol, an inhibitor of glycosphingolipid biosynthesis. In contrast, treatment with phosphatidylinositol-specific phospholipase C, an enzyme that cleaves Nogo receptors (NgR, another class of MAG receptor), or with a peptide inhibitor of an NgR-associated signaling molecule p75(NTR), failed to diminish MAG-mediated protection. Inhibiting the Rho-associated protein kinase ROCK reversed protection. We conclude that MAG protects neurites from acute toxic insult via a ganglioside-mediated signaling pathway that involves activation of RhoA. Understanding MAG-mediated protection may provide opportunities to reduce axonal damage and loss.

  8. Oxidative DNA Damage Mediated by Intranuclear MMP Activity Is Associated with Neuronal Apoptosis in Ischemic Stroke.

    PubMed

    Kimura-Ohba, Shihoko; Yang, Yi

    2016-01-01

    Evidence of the pathological roles of matrix metalloproteinases (MMPs) in various neurological disorders has made them attractive therapeutic targets. MMPs disrupt the blood-brain barrier and cause neuronal death and neuroinflammation in acute cerebral ischemia and are critical for angiogenesis during recovery. However, some challenges have to be overcome before MMPs can be further validated as drug targets in stroke injury. Identifying in vivo substrates of MMPs should greatly improve our understanding of the mechanisms of ischemic injury and is critical for providing more precise drug targets. Recent works have uncovered nontraditional roles for MMPs in the cytosol and nucleus. These have shed light on intracellular targets and biological actions of MMPs, adding additional layers of complexity for therapeutic MMP inhibition. In this review, we discussed the recent advances made in understanding nuclear location of MMPs, their regulation of intranuclear sorting, and their intranuclear proteolytic activity and substrates. In particular, we highlighted the roles of intranuclear MMPs in oxidative DNA damage, neuronal apoptosis, and neuroinflammation at an early stage of stroke insult. These novel data point to new putative MMP-mediated intranuclear actions in stroke-induced pathological processes and may lead to novel approaches to treatment of stroke and other neurological diseases.

  9. Efficacy and kinetics of opioid action on acutely dissociated neurons.

    PubMed

    Ingram, S; Wilding, T J; McCleskey, E W; Williams, J T

    1997-07-01

    Opioids have been shown to cause a potent inhibition of neurons in the locus ceruleus (LC) in vivo in brain slices and isolated neurons; however, the kinetics of opioid action have not been described. In this study, we used acutely isolated LC neurons to examine opioid and alpha2-adrenoceptor action on potassium and calcium currents. [Met]Enkephalin (ME), [D-Ser2,Leu5,Thr6]-enkephalin, etorphine, and [D-Ala2,N-Me-Phe4,Gly-ol5]enkephalin increased potassium conductance, whereas morphine and naloxone were antagonists. The time constant of potassium channel activation was approximately 0.7 sec and was the same for each agonist. The amplitude of the current and the time constant of decay were dependent on the agonist, suggesting that agonist efficacy and affinity, respectively, determined these parameters. The amplitude of potassium current induced by the alpha2-adrenoceptor agonist UK14304 was not significantly different from that induced by ME, but the time constant of current activation was half that of ME, and the decline was more rapid. When potassium conductances were blocked with the combination of internal cesium and external barium, opioid and alpha2 agonists had no effect at potentials more negative than -50 mV and decreased barium currents at potentials between -40 and +20 mV. Both morphine and clonidine caused a small inhibition of barium current. In dorsal root ganglion cells, morphine alone had small and inconsistent effects on the calcium current, but it always competitively antagonized the inhibition caused by [D-Ala2,N-Me-Phe4,Gly-ol5]enkephalin. The results in isolated LC neurons suggest 1) the amplitude and time course of the opioid-induced potassium current depend on agonist efficacy and affinity and 2) the coupling of both mu-opioid and alpha2-adrenoceptors to calcium channels seems to be more efficient than that to potassium channels.

  10. Intranasal Delivery of A Novel Amnion Cell Secretome Prevents Neuronal Damage and Preserves Function In A Mouse Multiple Sclerosis Model

    PubMed Central

    Khan, Reas S.; Dine, Kimberly; Bauman, Bailey; Lorentsen, Michael; Lin, Lisa; Brown, Helayna; Hanson, Leah R.; Svitak, Aleta L.; Wessel, Howard; Brown, Larry; Shindler, Kenneth S.

    2017-01-01

    The ability of a novel intranasally delivered amnion cell derived biologic to suppress inflammation, prevent neuronal damage and preserve neurologic function in the experimental autoimmune encephalomyelitis animal model of multiple sclerosis was assessed. Currently, there are no existing optic nerve treatment methods for disease or trauma that result in permanent vision loss. Demyelinating optic nerve inflammation, termed optic neuritis, induces permanent visual dysfunction due to retinal ganglion cell damage in multiple sclerosis and experimental autoimmune encephalomyelitis. ST266, the biological secretome of Amnion-derived Multipotent Progenitor cells, contains multiple anti-inflammatory cytokines and growth factors. Intranasally administered ST266 accumulated in rodent eyes and optic nerves, attenuated visual dysfunction, and prevented retinal ganglion cell loss in experimental optic neuritis, with reduced inflammation and demyelination. Additionally, ST266 reduced retinal ganglion cell death in vitro. Neuroprotective effects involved oxidative stress reduction, SIRT1-mediated mitochondrial function promotion, and pAKT signaling. Intranasal delivery of neuroprotective ST266 is a potential novel, noninvasive therapeutic modality for the eyes, optic nerves and brain. The unique combination of biologic molecules in ST266 provides an innovative approach with broad implications for suppressing inflammation in autoimmune diseases, and for preventing neuronal damage in acute neuronal injury and chronic neurodegenerative diseases such as multiple sclerosis. PMID:28139754

  11. Acute tinnitus and permanent audiovestibular damage after hepatitis B vaccination.

    PubMed

    DeJonckere, P H; de Surgères, G G

    2001-01-01

    Yeast-derived recombinant DNA hepatitis B vaccine usage has been widely accepted since the early 1990s, especially for high-risk patients. Severe adverse effects have been reported infrequently. Certain neurological complications raise concern for hepatitis B vaccine: central nervous system demyelination, acute myelitis, acute cerebellar ataxia, and various peripheral mononeuropathies. Case reports on tinnitus, hearing loss, and vestibular damage are extremely scarce. The case presented here concerns a professionally active nurse, born in 1953, with a medical history of progressive renal failure and hemodialysis. Eleven hours after a second injection of the hepatitis B vaccine Engerix B, an acute left-sided tinnitus occurred and, a few hours later, severe left hearing loss and intense vertigo. Tinnitus and the sensation of vertigo regressed fairly quickly, but the hearing loss and the vestibular paresis were permanent. Increased interpeak intervals on auditory brain responses and lack of recruitment suggested that the lesion probably is located at the level of cranial nerve VIII. From a medicolegal point of view, this audiovestibular damage had to be considered an accident at work and not as an occupational disease.

  12. Edaravone attenuates brain damage in rats after acute CO poisoning through inhibiting apoptosis and oxidative stress.

    PubMed

    Li, Qin; Bi, Ming Jun; Bi, Wei Kang; Kang, Hai; Yan, Le Jing; Guo, Yun-Liang

    2016-03-01

    Acute carbon monoxide (CO) poisoning is the most common cause of death from poisoning all over the world and may result in neuropathologic and neurophysiologic changes. Acute brain damage and delayed encephalopathy are the most serious complication, yet their pathogenesis is poorly understood. The present study aimed to evaluate the neuroprotective effects of Edaravone against apoptosis and oxidative stress after acute CO poisoning. The rat model of CO poisoning was established in a hyperbaric oxygen chamber by exposed to CO. Ultrastructure changes were observed by transmission electron microscopy (TEM). TUNEL stain was used to assess apoptosis. Immunohistochemistry and immunofluorescence double stain were used to evaluate the expression levels of heme oxygenase-1 (HO-1) and nuclear factor erythroid 2-related factor 2 (Nrf-2) protein and their relationship. By dynamically monitored the carboxyhemoglobin (HbCO) level in blood, we successfully established rat model of severe CO poisoning. Ultrastructure changes, including chromatin condensation, cytoplasm dissolution, vacuoles formation, nucleus membrane and cell organelles decomposition, could be observed after CO poisoning. Edaravone could improve the ultrastructure damage. CO poisoning could induce apoptosis. Apoptotic cells were widely distributed in cortex, striatum and hippocampus. Edaravone treatment attenuated neuronal apoptosis as compared with the poisoning group (P < 0.01). Basal expressions of HO-1 and Nrf-2 proteins were found in normal brain tissue. CO poisoning could activate HO-1/Nrf-2 pathway, start oxidative stress response. After the administration of Edaravone, the expression of HO-1 and Nrf-2 significantly increased (P < 0.01). These findings suggest that Edaravone may inhibit apoptosis, activate the Keapl-Nrf/ARE pathway, and thus improve the ultrastructure damage and neurophysiologic changes following acute CO poisoning.

  13. Damage to Arousal-Promoting Brainstem Neurons with Traumatic Brain Injury

    PubMed Central

    Valko, Philipp O.; Gavrilov, Yuri V.; Yamamoto, Mihoko; Noaín, Daniela; Reddy, Hasini; Haybaeck, Johannes; Weis, Serge; Baumann, Christian R.; Scammell, Thomas E.

    2016-01-01

    Study Objectives: Coma and chronic sleepiness are common after traumatic brain injury (TBI). Here, we explored whether injury to arousal-promoting brainstem neurons occurs in patients with fatal TBI. Methods: Postmortem examination of 8 TBI patients and 10 controls. Results: Compared to controls, TBI patients had 17% fewer serotonergic neurons in the dorsal raphe nucleus (effect size: 1.25), but the number of serotonergic neurons did not differ in the median raphe nucleus. TBI patients also had 29% fewer noradrenergic neurons in the locus coeruleus (effect size: 0.96). The number of cholinergic neurons in the pedunculopontine and laterodorsal tegmental nuclei (PPT/LDT) was similar in TBI patients and controls. Conclusions: TBI injures arousal-promoting neurons of the mesopontine tegmentum, but this injury is less severe than previously observed in hypothalamic arousal-promoting neurons. Most likely, posttraumatic arousal disturbances are not primarily caused by damage to these brainstem neurons, but arise from an aggregate of injuries, including damage to hypothalamic arousal nuclei and disruption of other arousal-related circuitries. Citation: Valko PO, Gavrilov YV, Yamamoto M, Noain D, Reddy H, Haybaeck J, Weis S, Baumann CR, Scammell TE. Damage to arousal-promoting brainstem neurons with traumatic brain injury. SLEEP 2016;39(6):1249–1252. PMID:27091531

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

    PubMed

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

    2015-07-01

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

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

    PubMed

    Casado Cerrada, Jesús; Pérez Calvo, Juan Ignacio

    2014-03-01

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

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

    PubMed

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

    2004-01-01

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

  17. APP as a Protective Factor in Acute Neuronal Insults

    PubMed Central

    Hefter, Dimitri; Draguhn, Andreas

    2017-01-01

    Despite its key role in the molecular pathology of Alzheimer’s disease (AD), the physiological function of amyloid precursor protein (APP) is unknown. Increasing evidence, however, points towards a neuroprotective role of this membrane protein in situations of metabolic stress. A key observation is the up-regulation of APP following acute (stroke, cardiac arrest) or chronic (cerebrovascular disease) hypoxic-ischemic conditions. While this mechanism may increase the risk or severity of AD, APP by itself or its soluble extracellular fragment APPsα can promote neuronal survival. Indeed, different animal models of acute hypoxia-ischemia, traumatic brain injury (TBI) and excitotoxicity have revealed protective effects of APP or APPsα. The underlying mechanisms involve APP-mediated regulation of calcium homeostasis via NMDA receptors (NMDAR), voltage-gated calcium channels (VGCC) or internal calcium stores. In addition, APP affects the expression of survival- or apoptosis-related genes as well as neurotrophic factors. In this review, we summarize the current understanding of the neuroprotective role of APP and APPsα and possible implications for future research and new therapeutic strategies. PMID:28210211

  18. Skeletal muscle DNA damage precedes spinal motor neuron DNA damage in a mouse model of Spinal Muscular Atrophy (SMA).

    PubMed

    Fayzullina, Saniya; Martin, Lee J

    2014-01-01

    Spinal Muscular Atrophy (SMA) is a hereditary childhood disease that causes paralysis by progressive degeneration of skeletal muscles and spinal motor neurons. SMA is associated with reduced levels of full-length Survival of Motor Neuron (SMN) protein, due to mutations in the Survival of Motor Neuron 1 gene. The mechanisms by which lack of SMN causes SMA pathology are not known, making it very difficult to develop effective therapies. We investigated whether DNA damage is a perinatal pathological event in SMA, and whether DNA damage and cell death first occur in skeletal muscle or spinal cord of SMA mice. We used a mouse model of severe SMA to ascertain the extent of cell death and DNA damage throughout the body of prenatal and newborn mice. SMA mice at birth (postnatal day 0) exhibited internucleosomal fragmentation in genomic DNA from hindlimb skeletal muscle, but not in genomic DNA from spinal cord. SMA mice at postnatal day 5, compared with littermate controls, exhibited increased apoptotic cell death profiles in skeletal muscle, by hematoxylin and eosin, terminal deoxynucleotidyl transferase dUTP nick end labeling, and electron microscopy. SMA mice had no increased cell death, no loss of choline acetyl transferase (ChAT)-positive motor neurons, and no overt pathology in the ventral horn of the spinal cord. At embryonic days 13 and 15.5, SMA mice did not exhibit statistically significant increases in cell death profiles in spinal cord or skeletal muscle. Motor neuron numbers in the ventral horn, as identified by ChAT immunoreactivity, were comparable in SMA mice and control littermates at embryonic day 15.5 and postnatal day 5. These observations demonstrate that in SMA, disease in skeletal muscle emerges before pathology in spinal cord, including loss of motor neurons. Overall, this work identifies DNA damage and cell death in skeletal muscle as therapeutic targets for SMA.

  19. 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

  20. [Responses of neurons of the associative parietal cortex during acute extinction restoration of a conditioned reflex].

    PubMed

    Prikhodchenko, N N

    1977-01-01

    The dynamics of spike neuronal activity in the parietal associative cortex was studied in the course of acute extinction and restoration of a conditioned reflex. Certain similarities have been found in neuronal firing during the reorganization of behavioral acts (transient processes in neuronal activity, general types of neuronal responses, etc.) The data obtained suggest the involvement of neurones of the parietal associative cortex in the processes related to the reorganization of behavioral acts, and the existence of common mechanisms of search for an optimal regime of neuronal assemblies functioning in different types of conditioned activity.

  1. Local opioid-sensitive afferent sensory neurones in the modulation of gastric damage induced by Paf.

    PubMed Central

    Esplugues, J. V.; Whittle, B. J.; Moncada, S.

    1989-01-01

    1. The role of local sensory neurones in modulating the extent of gastric mucosal damage induced by close-arterial infusion of platelet-activating factor (Paf 50 ng kg-1 min-1 for 10 min) has been investigated in the anaesthetized rat. 2. Local intra-arterial infusion of the neurotoxin, tetrodotoxin (TTX), substantially augmented the mucosal damage induced by Paf, as assessed by both macroscopic and histological techniques. 3. In rats pretreated with capsaicin 2 weeks prior to study, to induce a functional ablation of primary afferent neurones, gastric damage induced by Paf was significantly augmented. 4. Administration of morphine (0.75-3 mg kg-1 i.v.) or its peripherally acting quaternary analogue, N-methyl morphine (15 mg kg-1 i.v.), also significantly enhanced the gastric damage induced by Paf. 5. The potentiation by morphine of Paf-induced gastric damage was inhibited by administration of the opioid antagonists, naloxone (1 mg kg-1 i.v.) or the peripherally acting N-methyl nalorphine (3 mg kg-1 i.v.). 6. Administration of TTX or morphine alone, or pretreatment with capsaicin did not induce any detectable mucosal damage, suggesting that interference with local sensory neuronal activity itself does not directly induce mucosal disruption. 7. These results indicate that peripheral opiate-sensitive afferent sensory neurones play a physiological defensive role in the mucosa, attenuating the extent of gastric damage induced by Paf. PMID:2758231

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

    PubMed

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

    2014-01-01

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

  3. Fractal Dimension of EEG Activity Senses Neuronal Impairment in Acute Stroke

    PubMed Central

    Zappasodi, Filippo; Olejarczyk, Elzbieta; Marzetti, Laura; Assenza, Giovanni; Pizzella, Vittorio; Tecchio, Franca

    2014-01-01

    The brain is a self-organizing system which displays self-similarities at different spatial and temporal scales. Thus, the complexity of its dynamics, associated to efficient processing and functional advantages, is expected to be captured by a measure of its scale-free (fractal) properties. Under the hypothesis that the fractal dimension (FD) of the electroencephalographic signal (EEG) is optimally sensitive to the neuronal dysfunction secondary to a brain lesion, we tested the FD’s ability in assessing two key processes in acute stroke: the clinical impairment and the recovery prognosis. Resting EEG was collected in 36 patients 4–10 days after a unilateral ischemic stroke in the middle cerebral artery territory and 19 healthy controls. National Health Institute Stroke Scale (NIHss) was collected at T0 and 6 months later. Highuchi FD, its inter-hemispheric asymmetry (FDasy) and spectral band powers were calculated for EEG signals. FD was smaller in patients than in controls (1.447±0.092 vs 1.525±0.105) and its reduction was paired to a worse acute clinical status. FD decrease was associated to alpha increase and beta decrease of oscillatory activity power. Larger FDasy in acute phase was paired to a worse clinical recovery at six months. FD in our patients captured the loss of complexity reflecting the global system dysfunction resulting from the structural damage. This decrease seems to reveal the intimate nature of structure-function unity, where the regional neural multi-scale self-similar activity is impaired by the anatomical lesion. This picture is coherent with neuronal activity complexity decrease paired to a reduced repertoire of functional abilities. FDasy result highlights the functional relevance of the balance between homologous brain structures’ activities in stroke recovery. PMID:24967904

  4. Fractal dimension of EEG activity senses neuronal impairment in acute stroke.

    PubMed

    Zappasodi, Filippo; Olejarczyk, Elzbieta; Marzetti, Laura; Assenza, Giovanni; Pizzella, Vittorio; Tecchio, Franca

    2014-01-01

    The brain is a self-organizing system which displays self-similarities at different spatial and temporal scales. Thus, the complexity of its dynamics, associated to efficient processing and functional advantages, is expected to be captured by a measure of its scale-free (fractal) properties. Under the hypothesis that the fractal dimension (FD) of the electroencephalographic signal (EEG) is optimally sensitive to the neuronal dysfunction secondary to a brain lesion, we tested the FD's ability in assessing two key processes in acute stroke: the clinical impairment and the recovery prognosis. Resting EEG was collected in 36 patients 4-10 days after a unilateral ischemic stroke in the middle cerebral artery territory and 19 healthy controls. National Health Institute Stroke Scale (NIHss) was collected at T0 and 6 months later. Highuchi FD, its inter-hemispheric asymmetry (FDasy) and spectral band powers were calculated for EEG signals. FD was smaller in patients than in controls (1.447±0.092 vs 1.525±0.105) and its reduction was paired to a worse acute clinical status. FD decrease was associated to alpha increase and beta decrease of oscillatory activity power. Larger FDasy in acute phase was paired to a worse clinical recovery at six months. FD in our patients captured the loss of complexity reflecting the global system dysfunction resulting from the structural damage. This decrease seems to reveal the intimate nature of structure-function unity, where the regional neural multi-scale self-similar activity is impaired by the anatomical lesion. This picture is coherent with neuronal activity complexity decrease paired to a reduced repertoire of functional abilities. FDasy result highlights the functional relevance of the balance between homologous brain structures' activities in stroke recovery.

  5. CB2 Receptor Agonists Protect Human Dopaminergic Neurons against Damage from HIV-1 gp120

    PubMed Central

    Hu, Shuxian; Sheng, Wen S.; Rock, R. Bryan

    2013-01-01

    Despite the therapeutic impact of anti-retroviral therapy, HIV-1-associated neurocognitive disorder (HAND) remains a serious threat to AIDS patients, and there currently remains no specific therapy for the neurological manifestations of HIV-1. Recent work suggests that the nigrostriatal dopaminergic area is a critical brain region for the neuronal dysfunction and death seen in HAND and that human dopaminergic neurons have a particular sensitivity to gp120-induced damage, manifested as reduced function (decreased dopamine uptake), morphological changes, and reduced viability. Synthetic cannabinoids inhibit HIV-1 expression in human microglia, suppress production of inflammatory mediators in human astrocytes, and there is substantial literature demonstrating the neuroprotective properties of cannabinoids in other neuropathogenic processes. Based on these data, experiments were designed to test the hypothesis that synthetic cannabinoids will protect dopaminergic neurons against the toxic effects of the HIV-1 protein gp120. Using a human mesencephalic neuronal/glial culture model, which contains dopaminergic neurons, microglia, and astrocytes, we were able to show that the CB1/CB2 agonist WIN55,212-2 blunts gp120-induced neuronal damage as measured by dopamine transporter function, apoptosis and lipid peroxidation; these actions were mediated principally by the CB2 receptor. Adding supplementary human microglia to our cultures enhances gp120-induced damage; WIN55,212-2 is able to alleviate this enhanced damage. Additionally, WIN55,212-2 inhibits gp120-induced superoxide production by purified human microglial cells, inhibits migration of human microglia towards supernatants generated from gp120-stimulated human mesencephalic neuronal/glial cultures and reduces chemokine and cytokine production from the human mesencephalic neuronal/glial cultures. These data suggest that synthetic cannabinoids are capable of protecting human dopaminergic neurons from gp120 in a variety

  6. Protective effect of resveratrol against neuronal damage following transient global cerebral ischemia in mice.

    PubMed

    Hong, Jeong-Ho; Lee, Hyung; Lee, Seong-Ryong

    2016-01-01

    Resveratrol (3,5,4'-trihydroxystilbene) is a natural polyphenol which is rich in grape seeds and skin. Several studies have revealed that resveratrol possesses neuroprotective effects. In the case of global brain ischemia, there are few reports regarding the protective effect of resveratrol. Therefore, the influence of resveratrol on neuronal damage after transient global brain ischemia remains to be clarified. In the current study, C57BL/6 black mice were subjected to 20 min of transient global brain ischemia and followed by 72 h of reperfusion. Resveratrol (20 or 40 mg/kg, once daily, dissolved in 0.5% carboxymethylcellulose) was administered orally for 7 days before ischemia and daily until the mice were euthanized. The effect of lower or higher dose of resveratrol on neuronal damage, matrix metalloproteinase (MMP) activity and in situ DNA fragmentation (TUNEL) assay in the hippocampus after global ischemia was examined. Neuronal damages were remarkable in CA1 and CA2 pyramidal cell layers after global ischemia. In resveratrol-treated mice (40 mg/kg), neuronal damage was significantly reduced compared with vehicle-treated mice. Mice treated with resveratrol showed reduced MMP-9 activity. Resveratrol also inhibited TUNEL staining. These data suggest that resveratrol, a natural polyphenol, reduces hippocampal neuronal cell damage following transient global ischemia by reducing MMP-9 activity.

  7. 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

    2013-09-05

    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.

  8. Effect of Octreotide on Enteric Motor Neurons in Experimental Acute Necrotizing Pancreatitis

    PubMed Central

    Zou, Duowu; Wu, Wenbin; Li, Zhaoshen

    2012-01-01

    Background/Aims Amelioration of intestinal dysmotility and stasis during the early period of acute necrotizing pancreatitis (ANP) appears to be important to reduce the risks of secondary pancreatic infection. We aimed to characterize the association between the neuropathy of the enteric nervous system and gut dysfunction and to examine the effect of octreotide on motor innervation in the early stage of ANP. Methodology/Principal Findings The rats were randomly divided into eight groups: control+saline; control+octreotide; ANP+saline and ANP+octreotide (24 h, 48 h, 72 h). The spontaneous activity of ileal segments and the response to ACh, l-NNA were recorded. The alterations of myenteric neuronal nitric oxide synthase (nNOS), choline acetyltransferase (CHAT), PGP9.5 and somatostatin receptor 2 (SSTR2) immunoreactive cells were evaluated by immunofluorescence and the protein expression of nNOS and CHAT were evaluated by western blot. We found the amplitude of spontaneous contractions at 48 h and the response to ACh at 24 h declined in the ANP+saline rats. A higher contractile response to both ACh and to l-NNA was observed in the ANP+octreotide group, compared with the ANP+saline rats at 24 h. A significant reduction in the nNOS and cholinergic neurons was observed in ANP+saline rats at the three time points. However, this reduction was greatly ameliorated in the presence of octreotide at 24 h and 48 h. The protein expression of CHAT neurons at 24 h and the nNOS neurons at 48 h in the ANP+octreotide rats was much higher than the ANP+saline rats. Conclusion The pathogenesis of ileus in the early stage of ANP may be related to the neuropathy of the enteric nervous system. Octreotide may reduce the severity of ileus by lessening the damage to enteric motor innervation. PMID:23300603

  9. Acute renal damage in infants after first urinary tract infection.

    PubMed

    Cascio, Salvatore; Chertin, Boris; Yoneda, Akihiro; Rolle, Udo; Kelleher, Jeremiah; Puri, Prem

    2002-07-01

    Urinary tract infection (UTI) is one of the most common causes of unexplained fever in neonates. The aim of this study was to determine the incidence of urinary tract anomalies and acute renal damage in neonates who presented with first urinary tract infection in the first 8 weeks of life. We reviewed the records of 95 infants, who were hospitalised with UTI during a 6-year period (1994-1999). Patients with antenatally diagnosed hydronephrosis and incomplete radiological investigations were excluded from the study. Of the remaining 57 patients, 42 were boys and 15 girls. The mean age at diagnosis was 32 days (range 5-60 days). All patients underwent renal ultrasonography (US), voiding cystourethrogram (VCUG) and (99m)Tc-dimercaptosuccinic acid (DMSA) scan. Urinary tract abnormalities were detected in 20 (35%) patients. Vesicoureteral reflux (VUR) was found in 19 (33%) neonates, 7 girls and 12 boys. Acute cortical defects on DMSA scan were present in 19 kidneys of patients with VUR and in 25 of those without reflux. Only one-third of neonates after first symptomatic UTI had VUR. We recommend that US, VCUG, and DMSA scan should be routinely performed after the first UTI in infants younger than 8 weeks.

  10. Aberrant Synaptic Integration in Adult Lamina I Projection Neurons Following Neonatal Tissue Damage

    PubMed Central

    Li, Jie; Kritzer, Elizabeth; Craig, Paige E.

    2015-01-01

    Mounting evidence suggests that neonatal tissue damage evokes alterations in spinal pain reflexes which persist into adulthood. However, less is known about potential concomitant effects on the transmission of nociceptive information to the brain, as the degree to which early injury modulates synaptic integration and membrane excitability in mature spinal projection neurons remains unclear. Here we demonstrate that neonatal surgical injury leads to a significant shift in the balance between synaptic excitation and inhibition onto identified lamina I projection neurons of the adult mouse spinal cord. The strength of direct primary afferent input to mature spino-parabrachial neurons was enhanced following neonatal tissue damage, whereas the efficacy of both GABAergic and glycinergic inhibition onto the same population was compromised. This was accompanied by reorganization in the pattern of sensory input to adult projection neurons, which included a greater prevalence of monosynaptic input from low-threshold A-fibers when preceded by early tissue damage. In addition, neonatal incision resulted in greater primary afferent-evoked action potential discharge in mature projection neurons. Overall, these results demonstrate that tissue damage during early life causes a long-term increase in the gain of spinal nociceptive circuits, and suggest that the prolonged consequences of neonatal trauma may not be restricted to the spinal cord but rather include excessive ascending signaling to supraspinal pain centers. PMID:25673839

  11. Acute sun damage and photoprotective responses in whales.

    PubMed

    Martinez-Levasseur, Laura M; Gendron, Diane; Knell, Rob J; O'Toole, Edel A; Singh, Manuraj; Acevedo-Whitehouse, Karina

    2011-05-22

    Rising levels of ultraviolet radiation (UVR) secondary to ozone depletion are an issue of concern for public health. Skin cancers and intraepidermal dysplasia are increasingly observed in individuals that undergo chronic or excessive sun exposure. Such alterations of skin integrity and function are well established for humans and laboratory animals, but remain unexplored for mammalian wildlife. However, effects are unlikely to be negligible, particularly for species such as whales, whose anatomical or life-history traits force them to experience continuous sun exposure. We conducted photographic and histological surveys of three seasonally sympatric whale species to investigate sunburn and photoprotection. We find that lesions commonly associated with acute severe sun damage in humans are widespread and that individuals with fewer melanocytes have more lesions and less apoptotic cells. This suggests that the pathways used to limit and resolve UVR-induced damage in humans are shared by whales and that darker pigmentation is advantageous to them. Furthermore, lesions increased significantly in time, as would be expected under increasing UV irradiance. Apoptosis and melanocyte proliferation mirror this trend, suggesting that whales are capable of quick photoprotective responses. We conclude that the thinning ozone layer may pose a risk to the health of whales and other vulnerable wildlife.

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

    PubMed Central

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

    2016-01-01

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

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

    SciTech Connect

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

    1990-06-01

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

  14. [Pathogenic mechanisms of neuronal damage in multiple sclerosis].

    PubMed

    Flores-Alvarado, Luis Javier; Gabriel-Ortiz, Genaro; Pacheco-Mois, Fermín P; Bitzer-Quintero, K

    2015-06-01

    Multiple sclerosis is the most common cause of progressive neurological disability in young adults. This disease involves damage to the myelin sheath that normally insulates the electrical activity of nerve fibers. This leads to a wide range of symptoms as specific nerves become injured and lose their function. Epidemiological and experimental studies show that genetic alterations, antioxidant enzyme abnormalities and autoimmunity are risk factors for developing the disease. Recent evidence suggests that inflammation and oxidative stress within the central nervous system are major causes of ongoing tissue damage. Resident central nervous system cells and invading inflammatory cells release several reactive oxygen and nitrogen species which cause the histopathological features of multiple sclerosis: demyelization and axonal damage. The interplay between inflammatory and neurodegenerative processes results in an intermittent neurological disturbance followed by progressive accumulation of disability. Reductions in inflammation and oxidative stress status are important therapeutic strategies to slow or halt the disease processes. Therefore, several drugs are currently in trial in clinical practice to target this mechanism; particularly the use of supplements such as antioxidants and omega-3 polyunsaturated fatty acids, in order to improve the survival and quality of patients' lives.

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

    PubMed Central

    Bate, Clive; Rumbold, Louis; Williams, Alun

    2007-01-01

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

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

    PubMed

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

    2006-01-01

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

  17. Resveratrol suppresses calcium-mediated microglial activation and rescues hippocampal neurons of adult rats following acute bacterial meningitis.

    PubMed

    Sheu, Ji-Nan; Liao, Wen-Chieh; Wu, Un-In; Shyu, Ling-Yuh; Mai, Fu-Der; Chen, Li-You; Chen, Mei-Jung; Youn, Su-Chung; Chang, Hung-Ming

    2013-03-01

    Acute bacterial meningitis (ABM) is a serious disease with severe neurological sequelae. The intense calcium-mediated microglial activation and subsequently pro-inflammatory cytokine release plays an important role in eliciting ABM-related oxidative damage. Considering resveratrol possesses significant anti-inflammatory and anti-oxidative properties, the present study aims to determine whether resveratrol would exert beneficial effects on hippocampal neurons following ABM. ABM was induced by inoculating Klebsiella pneumoniae into adult rats intraventricularly. The time-of-flight secondary ion mass spectrometry (TOF-SIMS), Griffonia simplicifolia isolectin-B4 (GSA-IB4) and ionized calcium binding adaptor molecule 1 (Iba1) immunohistochemistry, enzyme-linked immunosorbent assay as well as malondialdehyde (MDA) measurement were used to examine the calcium expression, microglial activation, pro-inflammatory cytokine level, and extent of oxidative stress, respectively. In ABM rats, strong calcium signaling associated with enhanced microglial activation was observed in hippocampus. Increased microglial expression was coincided with intense production of pro-inflammatory cytokines and oxidative damage. However, in rats receiving resveratrol after ABM, the calcium intensity, microglial activation, pro-inflammatory cytokine and MDA levels were all significantly decreased. Quantitative data showed that much more hippocampal neurons were survived in resveratrol-treated rats following ABM. As resveratrol successfully rescues hippocampal neurons from ABM by suppressing the calcium-mediated microglial activation, therapeutic use of resveratrol may act as a promising strategy to counteract the ABM-induced neurological damage.

  18. Human prion protein-induced autophagy flux governs neuron cell damage in primary neuron cells.

    PubMed

    Moon, Ji-Hong; Lee, Ju-Hee; Nazim, Uddin Md; Lee, You-Jin; Seol, Jae-Won; Eo, Seong-Kug; Lee, John-Hwa; Park, Sang-Youel

    2016-05-24

    An unusual molecular structure of the prion protein, PrPsc is found only in mammals with transmissible prion diseases. Prion protein stands for either the infectious pathogen itself or a main component of it. Recent studies suggest that autophagy is one of the major functions that keep cells alive and has a protective effect against the neurodegeneration. In this study, we investigated that the effect of human prion protein on autophagy-lysosomal system of primary neuronal cells. The treatment of human prion protein induced primary neuron cell death and decreased both LC3-II and p62 protein amount indicating autophagy flux activation. Electron microscope pictures confirmed the autophagic flux activation in neuron cells treated with prion protein. Inhibition of autophagy flux using pharmacological and genetic tools prevented neuron cell death induced by human prion protein. Autophagy flux induced by prion protein is more activated in prpc expressing cells than in prpc silencing cells. These data demonstrated that prion protein-induced autophagy flux is involved in neuron cell death in prion disease and suggest that autophagy flux might play a critical role in neurodegenerative diseases including prion disease.

  19. MLKL inhibition attenuates hypoxia-ischemia induced neuronal damage in developing brain.

    PubMed

    Qu, Yi; Shi, Jing; Tang, Ying; Zhao, Fengyan; Li, Shiping; Meng, Junjie; Tang, Jun; Lin, Xuemei; Peng, Xiaodong; Mu, Dezhi

    2016-05-01

    Mixed lineage kinase domain-like protein (MLKL) is a critical molecule mediating cell necroptosis. However, its role in brain injury remains obscure. We first investigated the functions and mechanisms of MLKL in mediating neuronal damage in developing brain after hypoxia-ischemia. Neuronal necroptosis was induced by oxygen-glucose deprivation (OGD) plus caspase inhibitor zVAD treatment (OGD/zVAD). We found that two important necroptosis related proteins, receptor-interacting protein 1 and 3 (RIP1, RIP3) were upregulated. Furthermore, the interaction of RIP1-RIP3 with MLKL increased. Inhibition of MLKL through siRNA diminished RIP1-RIP3-MLKL interaction and attenuated neuronal death induced by OGD/zVAD. The translocation of oligomerized MLKL to the neuronal membrane leading to the injury of cellular membrane is the possible new mechanism of neuronal necroptosis. Animal experiment with neonatal rats further proved that MLKL inhibition attenuated brain damage induced by hypoxia-ischemia. These findings suggest that MLKL is a target to attenuate brain damage in developing brain.

  20. Indole-3-propionic acid attenuates neuronal damage and oxidative stress in the ischemic hippocampus.

    PubMed

    Hwang, In Koo; Yoo, Ki-Yeon; Li, Hua; Park, Ok Kyu; Lee, Choong Hyun; Choi, Jung Hoon; Jeong, Young-Gil; Lee, Yun Lyul; Kim, Young-Myeong; Kwon, Young-Guen; Won, Moo-Ho

    2009-07-01

    Tryptophan-derived indole compounds have been widely investigated as antioxidants and as free-radical scavengers. Indole-3-propionic acid (IPA), one of these compounds, is a deamination product of tryptophan. In the present study, we used Mongolian gerbils to investigate IPA's neuroprotective effects against ischemic damage and its antioxidative effects in the hippocampal CA1 region (CA1) after 5 min of transient forebrain ischemia. The repeated oral administration of IPA (10 mg/kg) for 15 days before ischemic surgery protected neurons from ischemic damage. In this group, the percentage of cresyl violet-positive neurons in the CA1 was 56.8% compared with that in the sham group. In the vehicle-treated group, glial fibrillary acidic protein (GFAP)-, S-100-, and vimentin-immunoreactive astrocytes and ionized calcium-binding adapter molecule 1 (Iba-1)- and isolectin B4 (IB4)-immunoreactive microglia were activated 4 days after ischemia/reperfusion, whereas in the IPA-treated ischemic group, GFAP, S-100, Iba-1, and IB4, but not vimentin, immunoreactivity was distinctly lower than that in the vehicle-treated ischemic groups. The administration of IPA significantly decreased the level of 4-hydroxy-2-nonenal, a marker of lipid peroxidation, in ischemic hippocampal homogenates compared with that in the vehicle-treated ischemic groups at various times after ischemia/reperfusion. In addition, immunostaining for 8-hydroxy-2'-deoxyguanosine showed DNA damage in pyramidal neurons in the ischemic CA1 was significantly lower in the IPA-treated ischemic groups than in the vehicle-treated ischemic groups. These results suggest that IPA protects neurons from ischemia-induced neuronal damage by reducing DNA damage and lipid peroxidation.

  1. A histopathological study of premature and mature infants with pontosubicular neuron necrosis: neuronal cell death in perinatal brain damage.

    PubMed

    Takizawa, Yuji; Takashima, Sachio; Itoh, Masayuki

    2006-06-20

    Perinatal hypoxic-ischemic brain damage is a major cause of neuronal and behavior deficits, in which the onset of injury can be before, at or after birth, and the effects may be delayed. Pontosubicular neuron necrosis (PSN) is one of perinatal hypoxic-ischemic brain injury and its pathological peculiarity is neuronal apoptosis. In this study, we investigated whether apoptotic cascade of PSN used a caspase-pathway or not, and whether hypoglycemia activated apoptosis or not. Sections of the pons of PSN with and without hypoglycemia were stained using terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) and immunohistochemistry for glial fibrillary acidic protein (GFAP), Bcl-2, Bcl-x and activated caspase 3. Additionally, we performed immunoblot analysis of Bcl-2, Bcl-x and activated caspase 3. TUNEL-positive cell was closely associated with the presence of karyorrhexis. Under combination of karyorrhectic and TUNEL-positive cells, number of apoptotic cells in premature brains was significantly more than in mature brains. Hypoxic-ischemic brain injury was considered to easily lead to apoptosis in premature infants. Moreover, as this pathophysiology, caspase-pathway activation contributed to neuronal death from caspase-immunoexpression analyses. PSN with hypoglycemia showed large number of apoptotic cells and higher expression of activated caspase 3. The result may be more severe with the background of hypoglycemia and prematurity complicated by hypoxia and/or ischemia.

  2. Estrogen inhibits tuberoinfundibular dopaminergic neurons but does not cause irreversible damage.

    PubMed

    Morel, Gustavo R; Carón, Rubén W; Cónsole, Gloria M; Soaje, Marta; Sosa, Yolanda E; Rodríguez, Silvia S; Jahn, Graciela A; Goya, Rodolfo G

    2009-12-16

    Dopaminergic neurons of the hypothalamic tuberoinfundibular dopaminergic (TIDA) system exert a tonic inhibitory control on prolactin (PRL) secretion whereas estrogen, known to inhibit TIDA neuron function, has been postulated to be toxic to TIDA neurons when it is chronically high. In order to determine whether estrogen in high doses can cause permanent damage to TIDA function, we submitted young female rats to continue high doses of estrogen administered, either centrally (intrahypothalamic estrogen implants) or peripherally (subcutaneous estrogen implants or weekly intramuscular (i.m.) injections for 7 weeks), subsequently withdrawing the steroid and observing the evolution of lactotrophes, serum PRL and TIDA neurons. Serum PRL was measured by radioimmunoassay whereas tyrosine hydroxylase positive (TH+) neurons and PRL cells were morphometrically assessed in sections of fixed hypothalami and pituitaries, respectively. After 30 days, hypothalamic estrogen implants induced a significant increase in serum PRL, whereas TH+ neurons were not detectable in the arcuate-periventricular hypothalamic (ARC) region of estrogen-implanted rats. Removal of implants on day 30 restored TH expression in the ARC and brought serum PRL back to basal levels 30 days after estrogen withdrawal. Subcutaneous or i.m. administration of estrogen for 7 weeks induced a marked hyperprolactinemia. However, 30 weeks after estrogen withdrawal, TH neuron numbers in the ARC were back to normal and serum PRL returned to basal levels. After peripheral but not central estrogen withdrawal, pituitary weight and lactotrophic cell numbers remained slightly increased. Our data suggest that estrogen even at high doses, does not cause permanent damage to TIDA neurons.

  3. Regulation of Müller Glial Dependent Neuronal Regeneration in the Damaged Adult Zebrafish Retina

    PubMed Central

    Gorsuch, Ryne A.; Hyde, David R.

    2013-01-01

    This article examines our current knowledge underlying the mechanisms involved in neuronal regeneration in the adult zebrafish retina. Zebrafish, which has the capacity to regenerate a wide variety of tissues and organs (including the fins, kidney, heart, brain, and spinal cord), has become the premier model system to study retinal regeneration due to the robustness and speed of the response and the variety of genetic tools that can be applied to study this question. It is now well documented that retinal damage induces the resident Müller glia to dedifferentiate and reenter the cell cycle to produce neuronal progenitor cells that continue to proliferate, migrate to the damaged retinal layer and differentiate into the missing neuronal cell types. Increasing our understanding of how these cellular events are regulated and occur in response to neuronal damage may provide critical information that can be applied to stimulating a regeneration response in the mammalian retina. In this review, we will focus on the genes/proteins that regulate zebrafish retinal regeneration and will attempt to critically evaluate how these factors may interact to correctly orchestrate the definitive cellular events that occur during regeneration. PMID:23880528

  4. Regulation of Müller glial dependent neuronal regeneration in the damaged adult zebrafish retina.

    PubMed

    Gorsuch, Ryne A; Hyde, David R

    2014-06-01

    This article examines our current knowledge underlying the mechanisms involved in neuronal regeneration in the adult zebrafish retina. Zebrafish, which has the capacity to regenerate a wide variety of tissues and organs (including the fins, kidney, heart, brain, and spinal cord), has become the premier model system to study retinal regeneration due to the robustness and speed of the response and the variety of genetic tools that can be applied to study this question. It is now well documented that retinal damage induces the resident Müller glia to dedifferentiate and reenter the cell cycle to produce neuronal progenitor cells that continue to proliferate, migrate to the damaged retinal layer and differentiate into the missing neuronal cell types. Increasing our understanding of how these cellular events are regulated and occur in response to neuronal damage may provide critical information that can be applied to stimulating a regeneration response in the mammalian retina. In this review, we will focus on the genes/proteins that regulate zebrafish retinal regeneration and will attempt to critically evaluate how these factors may interact to correctly orchestrate the definitive cellular events that occur during regeneration.

  5. Evaluation of the importance of astrocytes when screening for acute toxicity in neuronal cell systems.

    PubMed

    Woehrling, E K; Hill, E J; Coleman, M D

    2010-02-01

    Reliable, high throughput, in vitro preliminary screening batteries have the potential to greatly accelerate the rate at which regulatory neurotoxicity data is generated. This study evaluated the importance of astrocytes when predicting acute toxic potential using a neuronal screening battery of pure neuronal (NT2.N) and astrocytic (NT2.A) and integrated neuronal/astrocytic (NT2.N/A) cell systems derived from the human NT2.D1 cell line, using biochemical endpoints (mitochondrial membrane potential (MMP) depolarisation and ATP and GSH depletion). Following exposure for 72 h, the known acute human neurotoxicants trimethyltin-chloride, chloroquine and 6-hydroxydopamine were frequently capable of disrupting biochemical processes in all of the cell systems at non-cytotoxic concentrations. Astrocytes provide key metabolic and protective support to neurons during toxic challenge in vivo and generally the astrocyte containing cell systems showed increased tolerance to toxicant insult compared with the NT2.N mono-culture in vitro. Whilst there was no consistent relationship between MMP, ATP and GSH log IC(50) values for the NT2.N/A and NT2.A cell systems, these data did provide preliminary evidence of modulation of the acute neuronal toxic response by astrocytes. In conclusion, the suitability of NT2 neurons and astrocytes as cell systems for acute toxicity screening deserves further investigation.

  6. Prefrontal cortex gates acute morphine action on dopamine neurons in the ventral tegmental area.

    PubMed

    Liu, Changliang; Fang, Xing; Wu, Qianqian; Jin, Guozhang; Zhen, Xuechu

    2015-08-01

    Morphine excites dopamine (DA) neurons in the ventral tegmental area (VTA), an effect mediated by both local and systemic mechanisms. While the importance of the prefrontal cortex (PFC) - VTA circuit in opiate addiction is well established, little is known about how the PFC regulates the activity of VTA DA neurons upon morphine stimulation. One major challenge is that VTA DA neurons are highly heterogeneous in terms of projection and regulation, making their responses to PFC manipulations variable. Our previous work has identified a subgroup of VTA DA neurons exhibiting significant slow oscillation in their firing sequence, and demonstrated that most of these neurons are functionally connected with the PFC. In the present study, we focus our efforts only on VTA DA neurons expressing strong slow oscillation, and report that blocking the neuronal activity in the PFC remarkably attenuates the morphine-induced excitation of these neurons. Using in vivo microdialysis, we find that inactivation of the PFC also reduces the morphine-induced elevation of DA levels in the nucleus accumbens (NAc). Furthermore, 24 h after only single morphine exposure, PFC-inactivation failed to prevent subsequent morphine challenge from exciting VTA DA neurons, which is paralleled by altered response of PFC pyramidal neurons to morphine stimulation. Our results indicate that the PFC gates acute morphine action on a subset of VTA DA neurons, which is highly plastic and can be functionally remodeled by morphine exposure.

  7. Effect of acute lateral hemisection of the spinal cord on spinal neurons of postural networks.

    PubMed

    Zelenin, P V; Lyalka, V F; Orlovsky, G N; Deliagina, T G

    2016-12-17

    In quadrupeds, acute lateral hemisection of the spinal cord (LHS) severely impairs postural functions, which recover over time. Postural limb reflexes (PLRs) represent a substantial component of postural corrections in intact animals. The aim of the present study was to characterize the effects of acute LHS on two populations of spinal neurons (F and E) mediating PLRs. For this purpose, in decerebrate rabbits, responses of individual neurons from L5 to stimulation causing PLRs were recorded before and during reversible LHS (caused by temporal cold block of signal transmission in lateral spinal pathways at L1), as well as after acute surgical LHS at L1. Results obtained after Sur-LHS were compared to control data obtained in our previous study. We found that acute LHS caused disappearance of PLRs on the affected side. It also changed a proportion of different types of neurons on that side. A significant decrease and increase in the proportion of F- and non-modulated neurons, respectively, was found. LHS caused a significant decrease in most parameters of activity in F-neurons located in the ventral horn on the lesioned side and in E-neurons of the dorsal horn on both sides. These changes were caused by a significant decrease in the efficacy of posture-related sensory input from the ipsilateral limb to F-neurons, and from the contralateral limb to both F- and E-neurons. These distortions in operation of postural networks underlie the impairment of postural control after acute LHS, and represent a starting point for the subsequent recovery of postural functions.

  8. Exposure to 1800 MHz radiofrequency radiation induces oxidative damage to mitochondrial DNA in primary cultured neurons.

    PubMed

    Xu, Shangcheng; Zhou, Zhou; Zhang, Lei; Yu, Zhengping; Zhang, Wei; Wang, Yuan; Wang, Xubu; Li, Maoquan; Chen, Yang; Chen, Chunhai; He, Mindi; Zhang, Guangbin; Zhong, Min

    2010-01-22

    Increasing evidence indicates that oxidative stress may be involved in the adverse effects of radiofrequency (RF) radiation on the brain. Because mitochondrial DNA (mtDNA) defects are closely associated with various nervous system diseases and mtDNA is particularly susceptible to oxidative stress, the purpose of this study was to determine whether radiofrequency radiation can cause oxidative damage to mtDNA. In this study, we exposed primary cultured cortical neurons to pulsed RF electromagnetic fields at a frequency of 1800 MHz modulated by 217 Hz at an average special absorption rate (SAR) of 2 W/kg. At 24 h after exposure, we found that RF radiation induced a significant increase in the levels of 8-hydroxyguanine (8-OHdG), a common biomarker of DNA oxidative damage, in the mitochondria of neurons. Concomitant with this finding, the copy number of mtDNA and the levels of mitochondrial RNA (mtRNA) transcripts showed an obvious reduction after RF exposure. Each of these mtDNA disturbances could be reversed by pretreatment with melatonin, which is known to be an efficient antioxidant in the brain. Together, these results suggested that 1800 MHz RF radiation could cause oxidative damage to mtDNA in primary cultured neurons. Oxidative damage to mtDNA may account for the neurotoxicity of RF radiation in the brain.

  9. Acute damage threshold for infrared neural stimulation of the cochlea: functional and histological evaluation.

    PubMed

    Goyal, Vinay; Rajguru, Suhrud; Matic, Agnella I; Stock, Stuart R; Richter, Claus-Peter

    2012-11-01

    This article provides a mini review of the current state of infrared neural stimulation (INS), and new experimental results concerning INS damage thresholds. INS promises to be an attractive alternative for neural interfaces. With this method, one can attain spatially selective neural stimulation that is not possible with electrical stimulation. INS is based on the delivery of short laser pulses that result in a transient temperature increase in the tissue and depolarize the neurons. At a high stimulation rate and/or high pulse energy, the method bears the risk of thermal damage to the tissue from the instantaneous temperature increase or from potential accumulation of thermal energy. With the present study, we determined the injury thresholds in guinea pig cochleae for acute INS using functional measurements (compound action potentials) and histological evaluation. The selected laser parameters for INS were the wavelength (λ = 1,869 nm), the pulse duration (100 μs), the pulse repetition rate (250 Hz), and the radiant energy (0-127 μJ/pulse). For up to 5 hr of continuous irradiation at 250 Hz and at radiant energies up to 25 μJ/pulse, we did not observe any functional or histological damage in the cochlea. Functional loss was observed for energies above 25 μJ/pulse and the probability of injury to the target tissue resulting in functional loss increased with increasing radiant energy. Corresponding cochlear histology from control animals and animals exposed to 98 or 127 μJ/pulse at 250 Hz pulse repetition rate did not show a loss of spiral ganglion cells, hair cells, or other soft tissue structures of the organ of Corti. Light microscopy did not reveal any structural changes in the soft tissue either. Additionally, microcomputed tomography was used to visualize the placement of the optical fiber within the cochlea.

  10. Neuronal damage in chick and rat embryos following X-irradiation

    SciTech Connect

    Schneider, B.F.; Norton, S.

    1980-12-01

    Exposure of rat and chick embryos to X-irradiation at the time of development of neurons at the telencephalic-diencephalic border results in prolonged damage to neurons in this area as measured by neuronal nuclear size. A dose of 100 rads to the seven-day-old chick embryo has about the same effect as 125 rads to the 15-day-old rat fetus. The nuclear volume of large, multipolar neurons in the chick paleostriatum primitivum and the rat lateral preoptic area are reduced from 10 to 15%. Larger doses of X-irradiation to the chick (150 and 200 rads) cause progressively greater reductions in nuclear size. The large neurons which were measured in the rat and chick are morphologically similar in the two species. Both contain cytoplasmic acetylcholinesterase and have several branched, spiny dendritic processes. The similarity of response of chick and rat neurons to X-irradiation diminishes the significance of maternal factors as the cause of the effects of fetal irradiation in these experiments.

  11. Brain neuronal chromatin responses in acute soman intoxicated rats.

    PubMed

    Martin, L J; Doebler, J A; Wall, T J; Shih, T M; Anthony, A

    1986-08-01

    Male Sprague-Dawley rats (200 g) were injected subcutaneously with soman, a potent neuronal acetylcholinesterase (AChE) inhibitor, at doses of 0.5, 0.8 and 1.0 LD50 (1 LD50 = 135 micrograms/kg) before decapitation at 1 and 24 h post-exposure. Correlative data were obtained on the severity of brain AChE inactivation and physicochemical changes in nuclear chromatin of cerebrocortical (layer V) and striatal neurons using Feulgen-DNA (F-DNA) cytophotometry and ocular filar micrometry. Decreased lability of neurons to F-DNA acid hydrolysis (reduced F-DNA yield), nuclear shrinkage and chromatin aggregation (decreased chromophore area) were used as indices of suppression of genomic template activity; conversely, increases in F-DNA yield and chromophore area signify enhanced neuroexcitation. At 1 hr post-soman there was a dose-dependent inactivation of AChE with a moderate increase in chromatin activation, i.e., nuclear hypertrophy and chromatin dispersion. At 24 hr post-soman there was a partial restoration of AChE activity, notably in striatal neurons, with a suppression in chromatin template activity. These data indicate that actions of soman on neuronal functioning are time-dependent. The absence of any dose-related neuronal chromatin changes may signify existence of non-cholinergic mediated events.

  12. Mitochondrial division ensures the survival of postmitotic neurons by suppressing oxidative damage.

    PubMed

    Kageyama, Yusuke; Zhang, Zhongyan; Roda, Ricardo; Fukaya, Masahiro; Wakabayashi, Junko; Wakabayashi, Nobunao; Kensler, Thomas W; Reddy, P Hemachandra; Iijima, Miho; Sesaki, Hiromi

    2012-05-14

    Mitochondria divide and fuse continuously, and the balance between these two processes regulates mitochondrial shape. Alterations in mitochondrial dynamics are associated with neurodegenerative diseases. Here we investigate the physiological and cellular functions of mitochondrial division in postmitotic neurons using in vivo and in vitro gene knockout for the mitochondrial division protein Drp1. When mouse Drp1 was deleted in postmitotic Purkinje cells in the cerebellum, mitochondrial tubules elongated due to excess fusion, became large spheres due to oxidative damage, accumulated ubiquitin and mitophagy markers, and lost respiratory function, leading to neurodegeneration. Ubiquitination of mitochondria was independent of the E3 ubiquitin ligase parkin in Purkinje cells lacking Drp1. Treatment with antioxidants rescued mitochondrial swelling and cell death in Drp1KO Purkinje cells. Moreover, hydrogen peroxide converted elongated tubules into large spheres in Drp1KO fibroblasts. Our findings suggest that mitochondrial division serves as a quality control mechanism to suppress oxidative damage and thus promote neuronal survival.

  13. Acute interstitial pneumonia (AIP): relationship to Hamman-Rich syndrome, diffuse alveolar damage (DAD), and acute respiratory distress syndrome (ARDS).

    PubMed

    Mukhopadhyay, Sanjay; Parambil, Joseph G

    2012-10-01

    Acute interstitial pneumonia (AIP) is a term used for an idiopathic form of acute lung injury characterized clinically by acute respiratory failure with bilateral lung infiltrates and histologically by diffuse alveolar damage (DAD), a combination of findings previously known as the Hamman-Rich syndrome. This review aims to clarify the diagnostic criteria of AIP, its relationship with DAD and acute respiratory distress syndrome (ARDS), key etiologies that need to be excluded before making the diagnosis, and the salient clinical features. Cases that meet clinical and pathologic criteria for AIP overlap substantially with those that fulfill clinical criteria for ARDS. The main differences between AIP and ARDS are that AIP requires a histologic diagnosis of DAD and exclusion of known etiologies. AIP should also be distinguished from "acute exacerbation of IPF," a condition in which acute lung injury (usually DAD) supervenes on underlying usual interstitial pneumonia (UIP)/idiopathic pulmonary fibrosis (IPF).

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

    PubMed Central

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

    2015-01-01

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

  15. Protective effect of melatonin on myenteric neuron damage in experimental colitis in rats.

    PubMed

    Shang, Boxin; Shi, Haitao; Wang, Xiaoyan; Guo, Xiaoyan; Wang, Nan; Wang, Yan; Dong, Lei

    2016-04-01

    Inflammation of the colon in patients with ulcerative colitis (UC) causes pain and altered motility, at least in part through the damage of the myenteric neurons (MNs). Thus, it is important to evaluate new drugs for UC treatment that could also protect myenteric neurons efficiently. As a well-known neural protective and anti-inflammatory agent, melatonin could protect neurons from damage through the activation of the nuclear factor erythroid 2-related factor 2 and antioxidant responsive element (Nrf2-ARE) signaling pathway. Therefore, we investigated the potential protective effect of melatonin against MN damage during colitis induced by 2,4-dinitrobenzene sulfonic acid (DNBS) in rats. Colitis was induced by intracolonic (i.c.) instillation of DNBS and treated with melatonin at a dose of 2.5 mg/kg for 4 days. The damage of MN in the left colon was immunohistochemically evaluated in different groups. Ulcerations and inflammation in the colon were semiquantitatively observed. Myeloperoxidase (MPO), superoxide dismutase (SOD), and malondialdehyde (MDA) levels were detected to evaluate the inflammatory and oxidative stress status. The protein and mRNA expressions of Nrf2 and heme oxygenase-1 (HO-1) in the colon were detected by Western blot and quantitative polymerase chain reaction (qPCR), respectively. Melatonin partially prevented the loss of MN and alleviated the inflammation and oxidative stress induced by DNBS. In addition, melatonin markedly increased the Nrf2 and HO-1 level in the colitis. These results indicate that melatonin protects MN from damage by reducing inflammation and oxidative stress, effects that are partly mediated by the Nrf2-ARE pathway.

  16. Methamphetamine causes acute hyperthermia-dependent liver damage.

    PubMed

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

    2013-10-01

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

  17. Acute effect of exposure of mollusk single neuron to 900-MHz mobile phone radiation.

    PubMed

    Partsvania, B; Sulaberidze, T; Shoshiashvili, L; Modebadze, Z

    2011-09-01

    The goal of the present work was to explore the influence of commercially available cell phone irradiation on the single neuron excitability and memory processes. A Transverse Electromagnetic Cell (TEM Cell) was used to expose single neurons of mollusk to the electromagnetic field. Finite-Difference Time-Domain (FDTD) method was used for modeling the TEM Cell and the electromagnetic field interactions with living nerve ganglion and neurons. Neuron electrophysiology was investigated using standard microelectrode technique. The specific absorption rate (SAR) deposited into the single neuron was calculated to be 0.63 W/kg with a temperature increment of 0.1°C. After acute exposure, average firing threshold of the action potentials was not changed. However, the average latent period was significantly decreased. This indicates that together with latent period the threshold and the time of habituation might be altered during exposure. However, these alterations are transient and only latent period remains on the changed level.

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed Central

    Kazemi, Mohsen

    1998-01-01

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

  1. Activity-dependent modulation of gonadotrophin-releasing hormone neurone activity by acute oestradiol.

    PubMed

    Romanò, Nicola; Herbison, Allan E

    2012-10-01

    Oestradiol (E₂) exerts potent feedback actions upon gonadotrophin-releasing hormone (GnRH) neurones and part of this feedback action may occur through the rapid action of E₂. Using a transgenic GnRH-Pericam mouse line that allows real-time intracellular calcium concentrations ([Ca²⁺](i)) to be monitored in adult GnRH neurones in a brain slice preparation, we examined the acute effects of 100 pM-100 nM E₂ on [Ca²⁺](i) transients in spontaneously active GnRH neurones. Approximately 30% of GnRH neurones exhibit spontaneous [Ca²⁺](i) transients at a frequency greater than two transients/15 min in adult female mice. In these cells, treatment with an incremental 1, 10, 100 nM E₂ protocol or 100 pM E₂ alone resulted in the suppression or complete cessation of [Ca²⁺](i) transients in 15 of 18 (83%) GnRH neurones. This effect was mimicked by E₂ bound to albumin, suggesting a membrane site of action, and was maintained in oestrogen receptor β knockout mice, indicating that this receptor is not essential for the rapid suppression of [Ca²⁺](i) transients. These findings contrast with those GnRH neurones exhibiting very few or no [Ca²⁺](i) transients (< 2 transients/15 min) that exhibit the opposite response of being activated by acute E₂. A series of dual calcium-cell-attached electrical recordings showed that [Ca²⁺](i) transients were associated with GnRH neurone burst firing and that E₂ suppression or activation of [Ca²⁺](i) transients was mirrored by a depression or initiation of burst firing. Taken together, these studies demonstrate that the acute actions of E₂ on GnRH neurones are critically dependent upon their pattern of burst firing.

  2. Pulsed Electromagnetic Field Exposure Reduces Hypoxia and Inflammation Damage in Neuron-Like and Microglial Cells.

    PubMed

    Vincenzi, Fabrizio; Ravani, Annalisa; Pasquini, Silvia; Merighi, Stefania; Gessi, Stefania; Setti, Stefania; Cadossi, Ruggero; Borea, Pier Andrea; Varani, Katia

    2017-05-01

    In the present study, the effect of low-frequency, low-energy pulsed electromagnetic fields (PEMFs) has been investigated by using different cell lines derived from neuron-like cells and microglial cells. In particular, the primary aim was to evaluate the effect of PEMF exposure in inflammation- and hypoxia-induced injury in two different neuronal cell models, the human neuroblastoma-derived SH-SY5Y cells and rat pheochromocytoma PC12 cells and in N9 microglial cells. In neuron-like cells, live/dead and apoptosis assays were performed in hypoxia conditions from 2 to 48 h. Interestingly, PEMF exposure counteracted hypoxia damage significantly reducing cell death and apoptosis. In the same cell lines, PEMFs inhibited the activation of the hypoxia-inducible factor 1α (HIF-1α), the master transcriptional regulator of cellular response to hypoxia. The effect of PEMF exposure on reactive oxygen species (ROS) production in both neuron-like and microglial cells was investigated considering their key role in ischemic injury. PEMFs significantly decreased hypoxia-induced ROS generation in PC12, SH-SY5Y, and N9 cells after 24 or 48 h of incubation. Moreover, PEMFs were able to reduce some of the most well-known pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, and IL-8 release in N9 microglial cells stimulated with different concentrations of LPS for 24 or 48 h of incubation time. These results show a protective effect of PEMFs on hypoxia damage in neuron-like cells and an anti-inflammatory effect in microglial cells suggesting that PEMFs could represent a potential therapeutic approach in cerebral ischemic conditions. J. Cell. Physiol. 232: 1200-1208, 2017. © 2016 Wiley Periodicals, Inc.

  3. ATM-dependent phosphorylation of MEF2D promotes neuronal survival after DNA damage.

    PubMed

    Chan, Shing Fai; Sances, Sam; Brill, Laurence M; Okamoto, Shu-Ichi; Zaidi, Rameez; McKercher, Scott R; Akhtar, Mohd W; Nakanishi, Nobuki; Lipton, Stuart A

    2014-03-26

    Mutations in the ataxia telangiectasia mutated (ATM) gene, which encodes a kinase critical for the normal DNA damage response, cause the neurodegenerative disorder ataxia-telangiectasia (AT). The substrates of ATM in the brain are poorly understood. Here we demonstrate that ATM phosphorylates and activates the transcription factor myocyte enhancer factor 2D (MEF2D), which plays a critical role in promoting survival of cerebellar granule cells. ATM associates with MEF2D after DNA damage and phosphorylates the transcription factor at four ATM consensus sites. Knockdown of endogenous MEF2D with a short-hairpin RNA (shRNA) increases sensitivity to etoposide-induced DNA damage and neuronal cell death. Interestingly, substitution of endogenous MEF2D with an shRNA-resistant phosphomimetic MEF2D mutant protects cerebellar granule cells from cell death after DNA damage, whereas an shRNA-resistant nonphosphorylatable MEF2D mutant does not. In vivo, cerebella in Mef2d knock-out mice manifest increased susceptibility to DNA damage. Together, our results show that MEF2D is a substrate for phosphorylation by ATM, thus promoting survival in response to DNA damage. Moreover, dysregulation of the ATM-MEF2D pathway may contribute to neurodegeneration in AT.

  4. Mitochondrial stress-induced dopamine efflux and neuronal damage by malonate involves the dopamine transporter.

    PubMed

    Moy, Lily Y; Wang, Sheng-Ping; Sonsalla, Patricia K

    2007-02-01

    Endogenous striatal dopamine (DA) overflow has been associated with neuropathological conditions resulting from ischemia, psychostimulants, and metabolic inhibition. Malonate, a reversible inhibitor of succinate dehydrogenase, models the effects of energy impairment in neurodegenerative disorders. We have previously reported that the striatal DA efflux and damage to DA nerve terminals resulting from intrastriatal malonate infusions is prevented by prior DA depletion, suggesting that DA plays a role in the neuronal damage. We presently report that the malonate-induced DA efflux is partially mediated by reverse transport of DA from the cytosol to the extracellular space via the DA transporter (DAT). Pharmacological blockade of the DAT with a series of structurally different inhibitors [cocaine, mazindol, 1-(2-(bis(4-fluophenyl methoxy) ethyl)-4-(3-(4-fluorophenyl)-propyl)piperazine) dimethane sulfonate (GBR 13098) and methyl(-)-3beta-(p-fluorophenyl)-1alphaH,5alphaH-tropane-2beta-carboxylate1,5-naphthalene (Win 35,428)] attenuated malonate-induced DA overflow in vivo and protected mice against subsequent damage to DA nerve terminals. Consistent with these findings, the DAT inhibitors prevented malonate-induced damage to DA neurons in mesencephalic cultures and also protected against the loss of GABA neurons in this system. The DAT inhibitors did not modify malonate-induced formation of reactive oxygen species or lactate production, indicating that the DAT inhibitors neither exert antioxidant effects nor interfere with the actions of malonate. Taken together, these findings provide direct evidence that mitochondrial impairment and metabolic stress cause striatal DA efflux via the DAT and suggest that disruptions in DA homeostasis resulting from energy impairment may contribute to the pathogenesis of neurodegenerative diseases.

  5. Calpain inhibitor attenuated optic nerve damage in acute optic neuritis in rats

    PubMed Central

    Das, Arabinda; Guyton, M. Kelly; Smith, Amena; Wallace, Gerald; McDowell, Misty L.; Matzelle, Denise D.; Ray, Swapan K.; Banik, Naren L.

    2012-01-01

    Optic neuritis (ON), which is an acute inflammatory autoimmune demyelinating disease of the central nervous system (CNS), often occurs in multiple sclerosis (MS). ON is an early diagnostic sign in most MS patients caused by damage to the optic nerve leading to visual dysfunction. Various features of both MS and ON can be studied following induction of experimental autoimmune encephalomyelitis (EAE), an animal model of MS, in Lewis rats. Inflammation and cell death in the optic nerve, with subsequent damage to the retinal ganglion cells in the retina, are thought to correlate with visual dysfunction. Thus, characterizing the pathophysiological changes that lead to visual dysfunction in EAE animals may help develop novel targets for therapeutic intervention. We treated EAE animals with and without the calpain inhibitor calpeptin (CP). Our studies demonstrated that the Ca2+-activated neutral protease calpain was upregulated in the optic nerve following induction of EAE at the onset of clinical signs (OCS) of the disease and these changes were attenuated following treatment with CP. These reductions correlated with decreases in inflammation (cytokines, iNOS, COX-2, NF-κB), and microgliosis (i.e. activated microglia). We observed that calpain inhibition reduced astrogliosis (reactive astroglia) and expression of aquaporin 4 (AQP4). The balance of Th1/Th2 cytokine production and also expression of the Th1-related CCR5 and CXCR3 chemokine receptors influence many pathological processes and play both causative and protective roles in neuron damage. Our data indicated that CP suppressed cytokine imbalances. Also, Bax:Bcl-2 ratio, production of tBid, PARP-1, expression and activities of calpain and caspases, and internucleosomal DNA fragmentation were attenuated after treatment with CP. Our results demonstrated that CP decreased demyelination [loss of myelin basic protein (MBP)] and axonal damage [increase in dephosphorylated neurofilament protein (de-NFP), and also

  6. Acute stimulation of transplanted neurons improves motoneuron survival, axon growth, and muscle reinnervation.

    PubMed

    Grumbles, Robert M; Liu, Yang; Thomas, Christie M; Wood, Patrick M; Thomas, Christine K

    2013-06-15

    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.

  7. The acute phase of mild traumatic brain injury is characterized by a distance-dependent neuronal hypoactivity.

    PubMed

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

    2014-11-15

    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.

  8. 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

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

    PubMed

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

    2015-02-01

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

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

    PubMed Central

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

    2015-01-01

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

  11. Gene expression profile of activated microglia under conditions associated with dopamine neuronal damage.

    PubMed

    Thomas, David M; Francescutti-Verbeem, Dina M; Kuhn, Donald M

    2006-03-01

    Microglia are the resident antigen-presenting cells within the central nervous system (CNS), and they serve immune-like functions in protecting the brain against injury and invading pathogens. By contrast, activated microglia can secrete numerous reactants that damage neurons. The pathogenesis of various neurodegenerative diseases has been associated with microglial activation, but the signaling pathways that program a neuronally protective or destructive phenotype in microglia are not known. To increase the understanding of microglial activation, microarray analysis was used to profile the transcriptome of BV-2 microglial cells after activation. Microglia were activated by lipopolysaccharide, the HIV neurotoxic protein TAT, and dopamine quinone, each of which has been linked to dopamine neuronal damage. We identified 210 of 9882 genes whose expression was differentially regulated by all activators (116 increased and 94 decreased in expression). Gene ontology analysis assigned up-regulated genes to a number of specific biological processes and molecular functions, including immune response, inflammation, and cytokine/chemokine activity. Genes down-regulated in expression contribute to conditions that are permissive of microglial migration, lowered adhesion to matrix, lessened phagocytosis, and reduction in receptors that oppose chemotaxis and inflammation. These results elaborate a broad profile of microglial genes whose expression is altered by conditions associated with both neurodegenerative diseases and microglial activation.

  12. Preventive effect of Coriandrum sativum on neuronal damages in pentylentetrazole-induced seizure in rats

    PubMed Central

    Pourzaki, Mojtaba; Homayoun, Mansour; Sadeghi, Saeed; Seghatoleslam, Masoumeh; Hosseini, Mahmoud; Ebrahimzadeh Bideskan, Alireza

    2017-01-01

    Objective: Coriandrum sativum (C. sativum) as a medicinal plant has been pointed to have analgesic, hypnotic and anti-oxidant effects. In the current study, a possible preventive effect of the hydro-alcoholic extract of the plant on neuronal damages was examined in pentylenetetrazole (PTZ) rat model of seizure. Materials and Methods: Forty male rats were divided into five main groups and treated by (1) saline, (2) PTZ: 100 mg/kg PTZ (i.p) and (3-5) 50, 100 and 200 mg/kg of hydro-alcoholic extract of C. sativum during seven consecutive days before PTZ injection. After electrocorticography (ECoG), the brains were removed to use for histological examination. Results: All doses of the extract reduced duration, frequency and amplitude of the burst discharges while prolonged the latency of the seizure attacks (p<0.05, p<0.01, and p<0.001). Administration of all 3 doses of the extract significantly prevented from production of dark neurons (p<0.01, and p<0.001) and apoptotic cells (p<0.05, p<0.01, and p<0.001) in different areas of the hippocampus compared to PTZ group. Conclusion: The results of this study allow us to conclude that C. sativum, because of its antioxidant properties, prevents from neuronal damages in PTZ rat model of seizure. PMID:28348967

  13. Protective effects of C-phycocyanin against kainic acid-induced neuronal damage in rat hippocampus.

    PubMed

    Rimbau, V; Camins, A; Romay, C; González, R; Pallàs, M

    1999-12-03

    The neuroprotective role of C-phycocyanin was examined in kainate-injured brains of rats. The effect of three different treatments with C-phycocyanin was studied. The incidence of neurobehavioral changes was significantly lower in animals receiving C-phycocyanin. These animals also gained significantly more weight than the animals only receiving kainic acid, whereas their weight gain did not differed significantly from controls. Equivalent results were found when the neuronal damage in the hippocampus was evaluated through changes in peripheral benzodiazepine receptors (microglial marker) and heat shock protein 27 kD expression (astroglial marker). Our results are consistent with the oxygen radical scavenging properties of C-phycocyanin described elsewhere. Our findings and the virtual lack of toxicity of C-phycocyanin suggest this drug could be used to treat oxidative stress-induced neuronal injury in neurodegenerative diseases, such as Alzheimer's and Parkinson's.

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2013-04-01

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

  16. Acute treatment with 17beta-estradiol attenuates astrocyte-astrocyte and astrocyte-neuron communication.

    PubMed

    Rao, Shilpa P; Sikdar, Sujit Kumar

    2007-12-01

    Astrocytes are now recognized as dynamic signaling elements in the brain. Bidirectional communication between neurons and astrocytes involves integration of neuronal inputs by astrocytes and release of gliotransmitters that modulate neuronal excitability and synaptic transmission. The ovarian steroid hormone, 17beta-estradiol, in addition to its rapid actions on neuronal electrical activity can rapidly alter astrocyte intracellular calcium concentration ([Ca2+]i) through a membrane-associated estrogen receptor. Using calcium imaging and electrophysiological techniques, we investigated the functional consequences of acute treatment with estradiol on astrocyte-astrocyte and astrocyte-neuron communication in mixed hippocampal cultures. Mechanical stimulation of an astrocyte evoked a [Ca2+]i rise in the stimulated astrocyte, which propagated to the surrounding astrocytes as a [Ca2+]i wave. Following acute treatment with estradiol, the amplitude of the [Ca2+]i elevation in astrocytes around the stimulated astrocyte was attenuated. Further, estradiol inhibited the [Ca2+]i rise in individual astrocytes in response to the metabotropic glutamate receptor agonist, trans-(+/-)-1-amino-1,3-cyclopentanedicarboxylic acid. Mechanical stimulation of astrocytes induced [Ca2+]i elevations and electrophysiological responses in adjacent neurons. Estradiol rapidly attenuated the astrocyte-evoked glutamate-mediated [Ca2+]i rise and slow inward current in neurons. Also, the incidence of astrocyte-induced increase in spontaneous postsynaptic current frequency was reduced in the presence of estradiol. The effects of estradiol were stereo-specific and reversible following washout. These findings may indicate that the regulation of neuronal excitability and synaptic transmission by astrocytes is sensitive to rapid estradiol-mediated hormonal control.

  17. Proinflammatory cytokines provoke oxidative damage to actin in neuronal cells mediated by Rac1 and NADPH oxidase.

    PubMed

    Barth, Brian M; Stewart-Smeets, Shelli; Kuhn, Thomas B

    2009-06-01

    The proinflammatory cytokines TNFalpha and Il-1beta orchestrate the progression of CNS inflammation, which substantially contributes to neurodegeneration in many CNS pathologies. TNFalpha and Il-1beta stimulate actin filament reorganization in non-neuronal cells often accompanied by the formation of reactive oxygen species (ROS). Actin filament dynamics is vital for cellular plasticity, mitochondrial function, and gene expression despite being highly susceptible to oxidative damage. We demonstrated that, in neuronal cells, TNFalpha and Il-1beta stimulate a transient, redox-dependent reorganization of the actin cytoskeleton into lamellipodia under the regulation of Rac1 and a neuronal NADPH oxidase as the source of ROS. The persistent presence of intracellular ROS provoked oxidative damage (carbonylation) to actin coinciding with the loss of lamellipodia and arrest of cellular plasticity. Inhibition of NADPH oxidase activity or Rac1 abolished the adverse effects of cytokines. These findings suggest that oxidative damage to the neuronal actin cytoskeleton could represent a key step in CNS neurodegeneration.

  18. The membrane potential process of a single neuron seen as a cumulative damage process.

    PubMed

    Tejo, Mauricio; Niklitschek-Soto, Sebastián

    2016-12-01

    A simple integrate-and-fire mechanism of a single neuron can be compared with a cumulative damage process, where the spiking process is analogous to rupture sequences of a material under cycles of stress. Although in some cases lognormal-like patterns can be recognized in the inter-spike times under a simple integrate-and-fire mechanism, fatigue life models as the inverse Gaussian distribution and the Birnbaum-Saunders distribution (which was recently introduced in the neural activity framework) provide theoretical arguments that make them more suitable for the modeling of the resulting inter-spike times.

  19. Oxidative stress-induced CREB upregulation promotes DNA damage repair prior to neuronal cell death protection.

    PubMed

    Pregi, Nicolás; Belluscio, Laura María; Berardino, Bruno Gabriel; Castillo, Daniela Susana; Cánepa, Eduardo Tomás

    2017-01-01

    cAMP response element-binding (CREB) protein is a cellular transcription factor that mediates responses to different physiological and pathological signals. Using a model of human neuronal cells we demonstrate herein, that CREB is phosphorylated after oxidative stress induced by hydrogen peroxide. This phosphorylation is largely independent of PKA and of the canonical phosphoacceptor site at ser-133, and is accompanied by an upregulation of CREB expression at both mRNA and protein levels. In accordance with previous data, we show that CREB upregulation promotes cell survival and that its silencing results in an increment of apoptosis after oxidative stress. Interestingly, we also found that CREB promotes DNA repair after treatment with hydrogen peroxide. Using a cDNA microarray we found that CREB is responsible for the regulation of many genes involved in DNA repair and cell survival after oxidative injury. In summary, the neuroprotective effect mediated by CREB appears to follow three essential steps following oxidative injury. First, the upregulation of CREB expression that allows sufficient level of activated and phosphorylated protein is the primordial event that promotes the induction of genes of the DNA Damage Response. Then and when the DNA repair is effective, CREB induces detoxification and survival genes. This kinetics seems to be important to completely resolve oxidative-induced neuronal damages.

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

    PubMed

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

    2014-04-22

    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 10days 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 10mg/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 10.0mg/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 population 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 analyses 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 animal's behavior concomitantly with neuronal recordings.

  1. 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.

  2. Transcorneal alternating current stimulation after severe axon damage in rats results in "long-term silent survivor" neurons.

    PubMed

    Henrich-Noack, Petra; Lazik, Stefanie; Sergeeva, Elena; Wagner, Sebastian; Voigt, Nadine; Prilloff, Sylvia; Fedorov, Anton; Sabel, Bernhard A

    2013-06-01

    Transcorneal alternating current stimulation (tACS) was proposed to decrease acute death of retinal ganglion cells after optic nerve transection in rats, but it is not known if cell survival is long-term and associated with functional restoration. We therefore evaluated the effects of tACS in a rat model of optic nerve crush using anatomical, electrophysiological and behavioural measures. Rats were trained in a brightness discrimination visual task and the retinal ganglion cell number was quantified with in vivo confocal neuroimaging. Thereafter, severe optic nerve crush or sham crush was performed and rats were treated under anaesthesia either with tACS or sham stimulation immediately after the lesion and on day 3, 7, 11, 15, 19 and 23. Brightness discrimination was evaluated for 6 weeks and retinal ganglion cells were counted in vivo on post-crush days 7 and 28. In additional rats we studied the influence of tACS on bioelectrical activity. On post-lesion day 28, the tACS-treated group showed a neuronal survival of 28.2% which was significantly greater than in sham operates (8.6%). All animals with optic nerve crush were significantly impaired in brightness discrimination and did not recover performance, irrespective to which group they belonged. In accordance with this, there was no significant influence of the stimulation on EEG power spectra. In conclusion, tACS induced long-term neuronal protection from delayed retrograde cell death, but in this case of severe axonal damage tACS did not influence functional restoration and EEG signals recorded over the visual cortex.

  3. [Pharmacological correction of neuronal damage in sensomotor zone of frontal cortex under conditions of experimental cerebral blood flow pathology].

    PubMed

    Gorbacheva, S V; Belenichev, I F; Dunaev, V V; Bukhtiiarova, N V

    2007-01-01

    The administration of thiotriazoline, emoxypine and magnelong (a combined glycine-magnesium preparation) to animals with acute cerebral circulatory insufficiency showed significant neuroprotective effect in both acute and late ischemic periods, as indicated by the indices of cell density and number and the characteristics of apoptic and destructed neurons approaching those in the group of intact rats. Pyracetam showed cerebroprotective effect only in late ischemic period. Magnelong exhibited the most significant neuroprotective effect, maintaining cell density on the intact control level and reducing the number of apoptotic and destructed neurons.

  4. Role of platinum DNA damage-induced transcriptional inhibition in chemotherapy-induced neuronal atrophy and peripheral neurotoxicity.

    PubMed

    Yan, Fang; Liu, Johnson J; Ip, Virginia; Jamieson, Stephen M F; McKeage, Mark J

    2015-12-01

    Platinum-based anticancer drugs cause peripheral neurotoxicity by damaging sensory neurons within the dorsal root ganglia (DRG), but the mechanisms are incompletely understood. The roles of platinum DNA binding, transcription inhibition and altered cell size were investigated in primary cultures of rat DRG cells. Click chemistry quantitative fluorescence imaging of RNA-incorporated 5-ethynyluridine showed high, but wide ranging, global levels of transcription in individual neurons that correlated with their cell body size. Treatment with platinum drugs reduced neuronal transcription and cell body size to an extent that corresponded to the amount of preceding platinum DNA binding, but without any loss of neuronal cells. The effects of platinum drugs on neuronal transcription and cell body size were inhibited by blocking platinum DNA binding with sodium thiosulfate, and mimicked by treatment with a model transcriptional inhibitor, actinomycin D. In vivo oxaliplatin treatment depleted the total RNA content of DRG tissue concurrently with altering DRG neuronal size. These findings point to a mechanism of chemotherapy-induced peripheral neurotoxicity, whereby platinum DNA damage induces global transcriptional arrest leading in turn to neuronal atrophy. DRG neurons may be particularly vulnerable to this mechanism of toxicity because of their requirements for high basal levels of global transcriptional activity. Findings point to a new stepwise mechanism of chemotherapy-induced peripheral neurotoxicity, whereby platinum DNA damage induces global transcriptional arrest leading in turn to neuronal atrophy. Dorsal root ganglion neurons may be particularly vulnerable to this neurotoxicity because of their high global transcriptional outputs, demonstrated in this study by click chemistry quantitative fluorescence imaging.

  5. Caudate neuronal recording in freely behaving animals following acute and chronic dose response methylphenidate exposure.

    PubMed

    Claussen, Catherine M; Dafny, Nachum

    2015-09-01

    The misuse and abuse of the psychostimulant, methylphenidate (MPD) the drug of choice in the treatment of attention deficit hyperactivity disorder (ADHD) has seen a sharp uprising in recent years among both youth and adults for its cognitive enhancing effects and for recreational purposes. This uprise in illicit use has lead to many questions concerning the long-term consequences of MPD exposure. The objective of this study was to record animal behavior concomitantly with the caudate nucleus (CN) neuronal activity following acute and repetitive (chronic) dose response exposure to methylphenidate (MPD). A saline control and three MPD dose (0.6, 2.5, and 10.0mg/kg) groups were used. Behaviorally, the same MPD dose in some animals following chronic MPD exposure elicited behavioral sensitization and other animals elicited behavioral tolerance. Based on this finding, the CN neuronal population recorded from animals expressing behavioral sensitization was also evaluated separately from CN neurons recorded from animals expressing behavioral tolerance to chronic MPD exposure, respectively. Significant differences in CN neuronal population responses between the behaviorally sensitized and the behaviorally tolerant animals were observed for the 2.5 and 10.0mg/kg MPD exposed groups. For 2.5mg/kg MPD, behaviorally sensitized animals responded by decreasing their firing rates while behaviorally tolerant animals showed mainly an increase in their firing rates. The CN neuronal responses recorded from the behaviorally sensitized animals following 10.0mg/kg MPD responded by increasing their firing rates whereas the CN neuronal recordings from the behaviorally tolerant animals showed that approximately half decreased their firing rates in response to 10.0mg/kg MPD exposure. The comparison of percentage change in neuronal firing rates showed that the behaviorally tolerant animals trended to exhibit increases in their neuronal firing rates at ED1 following initial MPD exposure and

  6. 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

  7. Adaptations in responsiveness of brainstem pain-modulating neurons in acute compared with chronic inflammation.

    PubMed

    Cleary, Daniel R; Heinricher, Mary M

    2013-06-01

    Despite similar behavioral hypersensitivity, acute and chronic pain have distinct neural bases. We used intraplantar injection of complete Freund's adjuvant to directly compare activity of pain-modulating neurons in the rostral ventromedial medulla (RVM) in acute vs chronic inflammation. Heat-evoked and von Frey-evoked withdrawal reflexes and corresponding RVM neuronal activity were recorded in lightly anesthetized animals either during the first hour after complete Freund's adjuvant injection (acute) or 3 to 10 days later (chronic). Thermal and modest mechanical hyperalgesia during acute inflammation were associated with increases in the spontaneous activity of pain-facilitating ON-cells and suppression of pain-inhibiting OFF-cells. Acute hyperalgesia was reversed by RVM block, showing that the increased activity of RVM ON-cells is necessary for acute behavioral hypersensitivity. In chronic inflammation, thermal hyperalgesia had resolved but mechanical hyperalgesia had become pronounced. The spontaneous discharges of ON- and OFF-cells were not different from those in control subjects, but the mechanical response thresholds for both cell classes were reduced into the innocuous range. RVM block in the chronic condition worsened mechanical hyperalgesia. These studies identify distinct contributions of RVM ON- and OFF-cells to acute and chronic inflammatory hyperalgesia. During early immune-mediated inflammation, ON-cell spontaneous activity promotes hyperalgesia. After inflammation is established, the antinociceptive influence of OFF-cells is dominant, yet the lowered threshold for the OFF-cell pause allows behavioral responses to stimuli that would normally be considered innocuous. The efficacy of OFF-cells in counteracting sensitization of ascending transmission pathways could therefore be an important determining factor in development of chronic inflammatory pain.

  8. 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

  9. Neuroprotection of Ilex latifolia and caffeoylquinic acid derivatives against excitotoxic and hypoxic damage of cultured rat cortical neurons.

    PubMed

    Kim, Joo Youn; Lee, Hong Kyu; Hwang, Bang Yeon; Kim, SeungHwan; Yoo, Jae Kuk; Seong, Yeon Hee

    2012-06-01

    Ilex latifolia (Aquifoliaceae), one of the primary components of "Ku-ding-cha", has been used in Chinese folk medicine to treat headaches and various inflammatory diseases. A previous study demonstrated that the ethanol extract of I. latifolia could protect against ischemic apoptotic brain damage in rats. The present study investigated the protective activity of I. latifolia against glutamate-induced neurotoxicity using cultured rat cortical neurons in order to explain a possible mechanism related to its inhibitory effect on ischemic brain damage and identified potentially active compounds from it. Exposure of cultured cortical neurons to 500 μM glutamate for 12 h triggered neuronal cell death. I. latifolia (10-100 μg/mL) inhibited glutamate-induced neuronal death, elevation of intracellular calcium ([Ca(2+)](i)), generation of reactive oxygen species (ROS), the increase of a pro-apoptotic protein, BAX, and the decrease of an anti-apoptotic protein, BcL-2. Hypoxia-induced neuronal cell death was also inhibited by I. latifolia. 3,4-Dicaffeoylquinic acid (diCQA), 3,5-diCQA, and 3,5-diCQA methyl ester isolated from I. latifolia also inhibited the glutamate-induced increase in [Ca(2+)](i), generation of ROS, the change of apoptosis-related proteins, and neuronal cell death; and hypoxia-induced neuronal cell death. These results suggest that I. latifolia and its active compounds prevented glutamate-induced neuronal cell damage by inhibiting increase of [Ca(2+)](i), generation of ROS, and resultantly apoptotic pathway. In addition, the neuroprotective effects of I. latifolia on ischemia-induced brain damage might be associated with the anti-excitatory and anti-oxidative actions and could be attributable to these active compounds, CQAs.

  10. Mitochondrial division inhibitor 1 protects against mutant huntingtin-induced abnormal mitochondrial dynamics and neuronal damage in Huntington's disease.

    PubMed

    Manczak, Maria; Reddy, P Hemachandra

    2015-12-20

    The objective of this study was to determine the protective effects of the mitochondrial division inhibitor 1 (Mdivi1) in striatal neurons that stably express mutant Htt (STHDhQ111/Q111) and wild-type (WT) Htt (STHDhQ7/Q7). Using gene expression analysis, biochemical methods, transmission electron microscopy (TEM) and confocal microscopy methods, we studied (i) mitochondrial and synaptic activities by measuring mRNA and the protein levels of mitochondrial and synaptic genes, (ii) mitochondrial function and (iii) ultra-structural changes in mutant Htt neurons relative to WT Htt neurons. We also studied these parameters in Mdivil-treated and untreated WT and mutant Htt neurons. Increased expressions of mitochondrial fission genes, decreased expression of fusion genes and synaptic genes were found in the mutant Htt neurons relative to the WT Htt neurons. Electron microscopy of the mutant Htt neurons revealed a significantly increased number of mitochondria, indicating that mutant Htt fragments mitochondria. Biochemical analysis revealed defective mitochondrial functioning. In the Mdivil-treated mutant Htt neurons, fission genes were down-regulated, and fusion genes were up-regulated, suggesting that Mdivil decreases fission activity. Synaptic genes were up-regulated, and mitochondrial function was normal in the Mdivi1-treated mutant Htt neurons. Immunoblotting findings of mitochondrial and synaptic proteins agreed with mRNA findings. The TEM studies revealed that increased numbers of structurally intact mitochondria were present in Mdivi1-treated mutant Htt neurons. Increased synaptic and mitochondrial fusion genes and decreased fission genes were found in the Mdivi1-treated WT Htt neurons, indicating that Mdivi1 beneficially affects healthy neurons. Taken together, these findings suggest that Mdivi1 is protective against mutant Htt-induced mitochondrial and synaptic damage in HD neurons and that Mdivi1 may be a promising molecule for the treatment of HD patients.

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

    Kim, Da Jung; Kim, Yong Sik

    2016-03-01

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

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

    PubMed

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

    2016-08-25

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

  14. TDP-43 depletion induces neuronal cell damage through dysregulation of Rho family GTPases.

    PubMed

    Iguchi, Yohei; Katsuno, Masahisa; Niwa, Jun-ichi; Yamada, Shin-ichi; Sone, Jun; Waza, Masahiro; Adachi, Hiroaki; Tanaka, Fumiaki; Nagata, Koh-ichi; Arimura, Nariko; Watanabe, Takashi; Kaibuchi, Kozo; Sobue, Gen

    2009-08-14

    The 43-kDa TAR DNA-binding protein (TDP-43) is known to be a major component of the ubiquitinated inclusions characteristic of amyotrophic lateral sclerosis and frontotemporal lobar degeneration with ubiquitin-positive inclusions. Although TDP-43 is a nuclear protein, it disappears from the nucleus of affected neurons and glial cells, implicating TDP-43 loss of function in the pathogenesis of neurodegeneration. Here we show that the knockdown of TDP-43 in differentiated Neuro-2a cells inhibited neurite outgrowth and induced cell death. In knockdown cells, the Rho family members RhoA, Rac1, and Cdc42 GTPases were inactivated, and membrane localization of these molecules was reduced. In addition, TDP-43 depletion significantly suppressed protein geranylgeranylation, a key regulating factor of Rho family activity and intracellular localization. In contrast, overexpression of TDP-43 mitigated the cellular damage caused by pharmacological inhibition of geranylgeranylation. Furthermore administration of geranylgeranyl pyrophosphate partially restored cell viability and neurite outgrowth in TDP-43 knockdown cells. In summary, our data suggest that TDP-43 plays a key role in the maintenance of neuronal cell morphology and survival possibly through protein geranylgeranylation of Rho family GTPases.

  15. Effects of Acute Systemic Hypoxia and Hypercapnia on Brain Damage in a Rat Model of Hypoxia-Ischemia

    PubMed Central

    Zhang, Xuezhong; Wang, Nan; Tan, Jing; Fang, Xianhai; Wang, Qi; Tao, Tao; Li, Wenzhi

    2016-01-01

    Therapeutic hypercapnia has the potential for neuroprotection after global cerebral ischemia. Here we further investigated the effects of different degrees of acute systemic hypoxia in combination with hypercapnia on brain damage in a rat model of hypoxia and ischemia. Adult wistar rats underwent unilateral common carotid artery (CCA) ligation for 60 min followed by ventilation with normoxic or systemic hypoxic gas containing 11%O2,13%O2,15%O2 and 18%O2 (targeted to PaO2 30–39 mmHg, 40–49 mmHg, 50–59 mmHg, and 60–69 mmHg, respectively) or systemic hypoxic gas containing 8% carbon dioxide (targeted to PaCO2 60–80 mmHg) for 180 min. The mean artery pressure (MAP), blood gas, and cerebral blood flow (CBF) were evaluated. The cortical vascular permeability and brain edema were examined. The ipsilateral cortex damage and the percentage of hippocampal apoptotic neurons were evaluated by Nissl staining and terminal deoxynucleotidyl transferase-mediated 2′-deoxyuridine 5′-triphosphate-biotin nick end labeling (TUNEL) assay as well as flow cytometry, respectively. Immunofluorescence and western blotting were performed to determine aquaporin-4 (AQP4) expression. In rats treated with severe hypoxia (PaO2 < 50 mmHg), hypercapnia augmented the decline of MAP with cortical CBF and damaged blood–brain barrier permeability (p < 0.05). In contrast, in rats treated with mild to moderate hypoxia (PaO2 > 50 mmHg), hypercapnia protected against these pathophysiological changes. Moreover, hypercapnia treatment significantly reduced brain damage in the ischemic ipsilateral cortex and decreased the percentage of apoptotic neurons in the hippocampus after the CCA ligated rats were exposed to mild or moderate hypoxemia (PaO2 > 50 mmHg); especially under mild hypoxemia (PaO2 > 60 mmHg), hypercapnia significantly attenuated the expression of AQP4 protein with brain edema (p < 0.05). Hypercapnia exerts beneficial effects under mild to moderate hypoxemia and augments detrimental

  16. The mast cell stabilizer sodium cromoglycate reduces histamine release and status epilepticus-induced neuronal damage in the rat hippocampus.

    PubMed

    Valle-Dorado, María Guadalupe; Santana-Gómez, César Emmanuel; Orozco-Suárez, Sandra Adela; Rocha, Luisa

    2015-05-01

    Experiments were designed to evaluate changes in the histamine release, mast cell number and neuronal damage in hippocampus induced by status epilepticus. We also evaluated if sodium cromoglycate, a stabilizer of mast cells with a possible stabilizing effect on the membrane of neurons, was able to prevent the release of histamine, γ-aminobutyric acid (GABA) and glutamate during the status epilepticus. During microdialysis experiments, rats were treated with saline (SS-SE) or sodium cromoglycate (CG-SE) and 30 min later received the administration of pilocarpine to induce status epilepticus. Twenty-four hours after the status epilepticus, the brains were used to determine the neuronal damage and the number of mast cells in hippocampus. During the status epilepticus, SS-SE group showed an enhanced release of histamine (138.5%, p = 0.005), GABA (331 ± 91%, p ≤ 0.001) and glutamate (467%, p ≤ 0.001), even after diazepam administration. One day after the status epilepticus, SS-SE group demonstrated increased number of mast cells in Stratum pyramidale of CA1 (88%, p < 0.001) and neuronal damage in dentate gyrus, CA1 and CA3. In contrast to SS-SE group, rats from the CG-SE group showed increased latency to the establishment of the status epilepticus (p = 0.048), absence of wet-dog shakes, reduced histamine (but not GABA and glutamate) release, lower number of mast cells (p = 0.008) and reduced neuronal damage in hippocampus. Our data revealed that histamine, possibly from mast cells, is released in hippocampus during the status epilepticus. This effect may be involved in the subsequent neuronal damage and is diminished with sodium cromoglycate pretreatment.

  17. Preventive effect of Morinda citrifolia fruit juice on neuronal damage induced by focal ischemia.

    PubMed

    Harada, Shinichi; Hamabe, Wakako; Kamiya, Kohei; Satake, Toshiko; Yamamoto, Junichiro; Tokuyama, Shogo

    2009-03-01

    It is known that the fruit juice of Morinda citrifolia (M. citrifolia, Noni, Rubiaceae) has various pharmacological effects such as antioxidant or anti-inflammatory activities, which may help the inhibition of ischemic neuronal damage. Here, we examined the effect of the fruit juice of M. citrifolia (Noni juice) on the brain damage caused by ischemic stress in mice. Noni juice was obtained from the mature fruit grown in Okinawa (about 1.5 l/4 kg of fruit; 100% Okinawa Noni juice (ONJ). Male ddY mice were supplied with 3% or 10% juice in the drinking water for 7 d, and compared to the control group. On the 7th day, mice were subjected to 2 h of middle cerebral artery occlusion (MCAO). Interestingly, the intake of juice reduced the infarct volume as analyzed by 2,3,5-triphenyltetrazolium chloride (TTC) staining on the 3rd day of MCAO when compared to the control group. Furthermore, we found that the neurological deficit scores (NDS) were decreased after the reperfusion in the juice-supplied mice. On the other hand, the intake of juice did not affect the expression levels of antioxidant such as Cu/Zn superoxide dismutase. The present study suggests that Noni juice may have a preventive effect against cerebral ischemic stress, while further studies are needed to explain the detailed mechanism.

  18. Insulin inhibits AMPA-induced neuronal damage via stimulation of protein kinase B (Akt).

    PubMed

    Kim, S-J; Han, Y

    2005-02-01

    We designed a series of experiments to explore the neuroprotective effects of insulin. Insulin significantly inhibited the alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA)-induced neuronal cell damage as evidenced by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium-bromide (MTT) assay. However, insulin had little affect on the AMPA-induced glial cell damage. To determine whether insulin inhibits AMPA-induced excitotoxicity, we performed grease-gap recording assays using rat brain slices. In these experiments, insulin also significantly inhibited AMPA-induced depolarization. Flow cytometry and DNA fragmentation assays showed that insulin inhibits AMPA-induced apoptosis and DNA fragmentation, respectively. Insulin stimulated protein kinase B (Akt) activity, whereas AMPA pretreatment did not alter the insulin-stimulated Akt activity. On the contrary, insulin blocked induction of SAPK/JNK, which AMPA stimulated. Taken together, these results suggest that insulin exerts neuroprotective effects by inhibiting AMPA-induced excitotoxicity and apoptosis, possibly by activating Akt and blocking SAPK/JNK.

  19. Nicotinamide reduces acute cortical neuronal death and edema in the traumatically injured brain.

    PubMed

    Hoane, Michael R; Gilbert, David R; Holland, Michael A; Pierce, Jeremy L

    2006-11-06

    Previous studies have shown that administration of nicotinamide (Vitamin B(3)) in animal models of traumatic brain injury (TBI) and ischemia significantly reduced the size of infarction or injury and improved functional recovery. The present study evaluated the ability of nicotinamide to provide acute neuroprotection and edema reduction following TBI. Groups of rats were assigned to nicotinamide (500mg/kg) or saline (1.0ml/kg) treatment conditions and received contusion injuries or sham surgeries. Drug treatment was administered 15min following injury. Brains were harvested 24h later and either processed for histology or water content. Frozen sections were stained with the degenerating neuron stain (Fluoro-Jade B) (FJ) and cell counts were performed at the site of injury. Additional brains were processed for water content (a measure of injury-induced edema). Results of this study showed that administration of nicotinamide following TBI significantly reduced the number of FJ(+) neurons in the injured cortex compared to saline-treated animals. Examination of the water content of the brains also revealed that administration of nicotinamide significantly attenuated the amount of water compared to saline-treated animals in the injured cortex. These results indicate that nicotinamide administration significantly reduced neuronal death and attenuated cerebral edema following injury. The current findings suggest that nicotinamide significantly modulates acute pathophysiological processes following injury and that this may account for its beneficial effects on recovery of function following injury.

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

    PubMed

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

    2015-10-08

    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.

  1. Brain damage complicating septic shock: acute haemorrhagic leucoencephalitis as a complication of the generalised Shwartzman reaction.

    PubMed Central

    Graham, D I; Behan, P O; More, I A

    1979-01-01

    The neuropathological findings in six patients who developed neurological signs after the onset of "septic shock" caused by Gram-negative septicaemia are described. The changes in the brains were characteristic of acute haemorrhagic leucoencephalitis, and there was evidence, particularly in the kidneys, of disseminated intravascular coagulation with tubular necrosis and, in some, appearances indistinguishable from membrano-proliferative glomerulonephritis. It is agreed that acute haemorrhagic leucoencephalitis is another manifestation of a generalised Shwartzman reaction, and it is suggested that activation of complement is the final common pathway that produces tissue damage in the brain and kidney. Images PMID:762582

  2. Peroxisome proliferator-activated receptor α mediates acute effects of palmitoylethanolamide on sensory neurons.

    PubMed

    Khasabova, Iryna A; Xiong, Yee; Coicou, Lia G; Piomelli, Daniele; Seybold, Virginia

    2012-09-12

    The amplitude of the depolarization-evoked Ca2+ transient is larger in dorsal root ganglion (DRG) neurons from tumor-bearing mice compared with that of neurons from naive mice, and the change is mimicked by coculturing DRG neurons with the fibrosarcoma cells used to generate the tumors (Khasabova et al., 2007). The effect of palmitoylethanolamide (PEA), a ligand for the peroxisome proliferator-activated receptor α (PPARα), was determined on the evoked-Ca2+ transient in the coculture condition. The level of PEA was reduced in DRG cells from tumor-bearing mice as well as those cocultured with fibrosarcoma cells. Pretreatment with PEA, a synthetic PPARα agonist (GW7647), or ARN077, an inhibitor of the enzyme that hydrolyzes PEA, acutely decreased the amplitude of the evoked Ca2+ transient in small DRG neurons cocultured with fibrosarcoma cells. The PPARα antagonist GW6471 blocked the effect of each. In contrast, the PPARα agonist was without effect in the control condition, but the antagonist increased the amplitude of the Ca2+ transient, suggesting that PPARα receptors are saturated by endogenous ligand under basal conditions. Effects of drugs on mechanical sensitivity in vivo paralleled their effects on DRG neurons in vitro. Local injection of ARN077 decreased mechanical hyperalgesia in tumor-bearing mice, and the effect was blocked by GW6471. These data support the conclusion that the activity of DRG neurons is rapidly modulated by PEA through a PPARα-dependent mechanism. Moreover, agents that increase the activity of PPARα may provide a therapeutic strategy to reduce tumor-evoked pain.

  3. Cellular and molecular characterization of Ca2+ currents in acutely isolated, adult rat neostriatal neurons.

    PubMed

    Bargas, J; Howe, A; Eberwine, J; Cao, Y; Surmeier, D J

    1994-11-01

    Ca2+ currents in acutely isolated, adult rat neostriatal neurons were studied with whole-cell voltage-clamp techniques. In the vast majority of neurons (approximately 90%, n > 250), currents were exclusively of the high-voltage-activated (HVA) type. HVA currents activated near -40 mV and reached their maximum amplitude near 0 mV. Quasi-steady-state inactivation curves in many neurons were well fitted only with a sum of Boltzmann functions, suggesting that the HVA currents were heterogeneous. Although the block of whole-cell current by Cd2+ was well fitted with a single isotherm having an IC50 of near 1 microM, experiments with organic channel antagonists suggested that at least four types of HVA channels were expressed by most cells. On average, the L-channel antagonist nifedipine (5-10 microM) blocked 31 +/- 10% of the whole-cell current (n = 20), the N-channel antagonist omega-conotoxin GVIA (omega-CgTx) (2-5 microM) blocked 27 +/- 11% (n = 20), and the P-channel antagonist omega-agatoxin IVA (100-500 nM) blocked 21 +/- 10% (n = 18). In many neurons, the block by omega-CgTx was partially or completely reversible. In cells tested with a combination of these antagonists, 34 +/- 17% of the peak Ca2+ current remained unblocked (n = 13). Single-cell expression profiling of medium-sized neurons revealed the presence of rbA and rbB Ca2+ channel alpha 1 subunit mRNAs but low or undetectable levels of rbC mRNA (n = 12). These findings suggest that although adult neostriatal projection neurons do not express significant levels of LVA Ca2+ current, they do express a pharmacologically and structurally heterogeneous population of HVA currents.

  4. Overexpression of SOD1 in transgenic rats protects vulnerable neurons against ischemic damage after global cerebral ischemia and reperfusion.

    PubMed

    Chan, P H; Kawase, M; Murakami, K; Chen, S F; Li, Y; Calagui, B; Reola, L; Carlson, E; Epstein, C J

    1998-10-15

    Transient global cerebral ischemia resulting from cardiac arrest is known to cause selective death in vulnerable neurons, including hippocampal CA1 pyramidal neurons. It is postulated that oxygen radicals, superoxide in particular, are involved in cell death processes. To test this hypothesis, we first used in situ imaging of superoxide radical distribution by hydroethidine oxidation in vulnerable neurons. We then generated SOD1 transgenic (Tg) rats with a five-fold increase in copper zinc superoxide dismutase activity. The Tg rats and their non-Tg wild-type littermates were subjected to 10 min of global ischemia followed by 1 and 3 d of reperfusion. Neuronal damage, as assessed by cresyl violet staining and DNA fragmentation analysis, was significantly reduced in the hippocampal CA1 region, cortex, striatum, and thalamus in SOD1 Tg rats at 3 d, as compared with the non-Tg littermates. There were no changes in the hippocampal CA3 subregion and dentate gyrus, resistant areas in both SOD1 Tg and non-Tg rats. Quantitative analysis of the damaged CA1 subregion showed marked neuroprotection against transient global cerebral ischemia in SOD1 Tg rats. These results suggest that superoxide radicals play a role in the delayed ischemic death of hippocampal CA1 neurons. Our data also indicate that SOD1 Tg rats are useful tools for studying the role of oxygen radicals in the pathogenesis of neuronal death after transient global cerebral ischemia.

  5. Radiation treatment inhibits monocyte entry into the optic nerve head and prevents neuronal damage in a mouse model of glaucoma.

    PubMed

    Howell, Gareth R; Soto, Ileana; Zhu, Xianjun; Ryan, Margaret; Macalinao, Danilo G; Sousa, Gregory L; Caddle, Lura B; MacNicoll, Katharine H; Barbay, Jessica M; Porciatti, Vittorio; Anderson, Michael G; Smith, Richard S; Clark, Abbot F; Libby, Richard T; John, Simon W M

    2012-04-01

    Glaucoma is a common ocular disorder that is a leading cause of blindness worldwide. It is characterized by the dysfunction and loss of retinal ganglion cells (RGCs). Although many studies have implicated various molecules in glaucoma, no mechanism has been shown to be responsible for the earliest detectable damage to RGCs and their axons in the optic nerve. Here, we show that the leukocyte transendothelial migration pathway is activated in the optic nerve head at the earliest stages of disease in an inherited mouse model of glaucoma. This resulted in proinflammatory monocytes entering the optic nerve prior to detectable neuronal damage. A 1-time x-ray treatment prevented monocyte entry and subsequent glaucomatous damage. A single x-ray treatment of an individual eye in young mice provided that eye with long-term protection from glaucoma but had no effect on the contralateral eye. Localized radiation treatment prevented detectable neuronal damage and dysfunction in treated eyes, despite the continued presence of other glaucomatous stresses and signaling pathways. Injection of endothelin-2, a damaging mediator produced by the monocytes, into irradiated eyes, combined with the other glaucomatous stresses, restored neural damage with a topography characteristic of glaucoma. Together, these data support a model of glaucomatous damage involving monocyte entry into the optic nerve.

  6. The new P2Y-like receptor G protein-coupled receptor 17 mediates acute neuronal injury and late microgliosis after focal cerebral ischemia in rats.

    PubMed

    Zhao, B; Zhao, C Z; Zhang, X Y; Huang, X Q; Shi, W Z; Fang, S H; Lu, Y B; Zhang, W P; Xia, Q; Wei, E Q

    2012-01-27

    G protein-coupled receptor 17 (GPR17), the new P2Y-like receptor, is phylogenetically related to the P2Y and cysteinyl leukotriene receptors, and responds to both uracil nucleotides and cysteinyl leukotrienes. GPR17 has been proposed to be a damage sensor in ischemic stroke; however, its role in brain inflammation needs further detailed investigation. Here, we extended previous studies on the spatiotemporal profiles of GPR17 expression and localization, and their implications for brain injury after focal cerebral ischemia. We found that in the ischemic core, GPR17 mRNA and protein levels were upregulated at both 12-24 h and 7-14 days, but in the boundary zone the levels increased 7-14 days after reperfusion. The spatiotemporal pattern of GPR17 expression well matched the acute and late (subacute/chronic) responses in the ischemic brain. According to previous findings, in the acute phase, after ischemia (24 h), upregulated GPR17 was localized in injured neurons in the ischemic core and in a few microglia in the ischemic core and boundary zone. In the late phase (14 days), it was localized in microglia, especially in activated (ED1-positive) microglia in the ischemic core, but weakly in most microglia in the boundary zone. No GPR17 was detectable in astrocytes. GPR17 knockdown by a small interfering RNA attenuated the neurological dysfunction, infarction, and neuron loss at 24 h, and brain atrophy, neuron loss, and microglial activation at 14 days after reperfusion. Thus, GPR17 might mediate acute neuronal injury and late microgliosis after focal cerebral ischemia.

  7. Neuronal Over-expression of ACE2 Protects Brain from Ischemia-induced Damage

    PubMed Central

    Chen, Ji; Zhao, Yuhui; Chen, Shuzhen; Wang, Jinju; Xiao, Xiang; Ma, Xiaotang; Penchikala, Madhuri; Xia, Huijing; Lazartigues, Eric; Zhao, Bin; Chen, Yanfang

    2014-01-01

    Angiotensin (Ang) II exaggerates cerebral injury in ischemic damage. Angiotensin-converting enzyme type 2 (ACE2) converts Ang II into Ang (1–7) and thus, may protect against the effects of Ang II. We hypothesized that neuronal ACE2 over-expression decreases ischemic stroke in mice with Ang II overproduction. Human renin and angiotensinogen double transgenic (RA) mice and RA mice with neuronal over-expression of ACE2 (SARA) were used for the study. The mean arterial pressure (MAP) was calculated from telemetry-recorded blood pressure (BP). SARA mice were infused peripherally with Norepinephrine to “clamp” the BP, or intracerebroventricularly-infused with a Mas receptor antagonist (A-779). Middle cerebral artery occlusion (MCAO) surgery was performed to induce permanent focal ischemic stroke. Cerebral blood flow (CBF) and neurological function were determined. Two days after surgery, brain samples were collected for various analyses. Results showed: 1) When compared to chronically hypertensive RA mice, SARA mice had lower basal MAP, less MCAO-induced infarct volume, and increased CBF, neurological function and cerebral microvascular density in the peri-infarct area; 2) These changes in SARA mice were not altered after MAP “clamping”, but partially reversed by brain infusion of A-779; 3) Ang (1–7)/Ang II ratio, angiogenic factors, endothelial nitric oxide synthase (eNOS) expression and nitric oxide production were increased, whereas, NADPH oxidase subunits and reactive oxygen species were decreased in the brain of SARA mice. ACE2 protects brain from ischemic injury via the regulation of NADPH oxidase/eNOS pathways by changing Ang (1–7)/Ang II ratio, independently of MAP changes. PMID:24440367

  8. Evaluation of plasma von Willebrand factor as a biomarker for acute arterial damage in rats.

    PubMed

    Newsholme, S J; Thudium, D T; Gossett, K A; Watson, E S; Schwartz, L W

    2000-01-01

    Plasma von Willebrand factor (vWF) was evaluated as a potential biomarker of acute arterial damage in rats after a vasotoxic dose of the dopaminergic vasodilator, fenoldopam (FP). Male Sprague-Dawley rats were given FP or isotonic saline by subcutaneous injection, and plasma vWF was measured at 2, 6, and 24 hours after challenge. Mean plasma vWF values increased in FP-treated rats compared to controls at 2 hours (167 vs 122%; p < 0.05) and 6 hours postdose (172 vs 130%; p < 0.01) but were comparable to control values after 24 hours. Mesenteric arterial lesions were observed microscopically in all FP-treated rats 24 hours postdose but were not present in rats at 1, 2, 4, 6, or 8 hours after FP challenge. Further, plasma vWF concentrations increased in saline-treated rats after only the minimal perturbation of repeated venipuncture. These results indicate an early, minimal, and transient release of vWF that precedes the onset of morphologically evident vascular damage. The minimal increases in plasma vWF concentrations were of limited predictive value, may be more reflective of an acute-phase reactant response, and were not considered a reliable biomarker of acute FP-induced arterial damage in the rat.

  9. Pronase acutely modifies high voltage-activated calcium currents and cell properties of Lymnaea neurons.

    PubMed

    Hermann, P M; Lukowiak, K; Wildering, W C; Bulloch, A G

    1997-12-01

    Pronase E ('pronase') is one of the proteolytic enzymes that are used in preparative procedures such as cell isolation and to soften the sheath of invertebrate ganglia. Although several effects of proteolytic enzymes on the physiology of non-neuronal tissues have been described, the effects of these enzymes on central neurons have received little attention. We examined the effects of bath-applied pronase on neurons in the Lymnaea central nervous system and in vitro. Pronase caused action potential broadening in neurons that exhibit a shoulder on the repolarization phase of their action potentials. This effect of pronase was accompanied by, although unrelated to, a depolarization and decrease in action potential interval. Some, but not all, effects of pronase in the central nervous system were reversible. For example, the decreases in membrane potential and action potential interval were both reversed after approximately 1 h of washing with saline. However, the effect of pronase on the action potential duration was not reversed after a period of 90 min. The modulation of action potential width prompted us to examine Ca2+ currents. Exposure to pronase resulted in an increase in both peak and late high voltage-activated Ca2+ currents in isolated neurons. Pronase neither changed the inactivation rate nor caused a shift in the current-voltage relationship of the current. The changes in action potential duration could be prevented by application of 0.1 mM Cd2+, indicating that the action potential broadening caused by pronase depends on Ca2+ influx. This is the first systematic study of the acute and direct actions of pronase on Ca2+ currents and cell properties both in the CNS and in vitro.

  10. Quasimodo mediates daily and acute light effects on Drosophila clock neuron excitability.

    PubMed

    Buhl, Edgar; Bradlaugh, Adam; Ogueta, Maite; Chen, Ko-Fan; Stanewsky, Ralf; Hodge, James J L

    2016-11-22

    We have characterized a light-input pathway regulating Drosophila clock neuron excitability. The molecular clock drives rhythmic electrical excitability of clock neurons, and we show that the recently discovered light-input factor Quasimodo (Qsm) regulates this variation, presumably via an Na(+), K(+), Cl(-) cotransporter (NKCC) and the Shaw K(+) channel (dKV3.1). Because of light-dependent degradation of the clock protein Timeless (Tim), constant illumination (LL) leads to a breakdown of molecular and behavioral rhythms. Both overexpression ((OX)) and knockdown ((RNAi)) of qsm, NKCC, or Shaw led to robust LL rhythmicity. Whole-cell recordings of the large ventral lateral neurons (l-LNv) showed that altering Qsm levels reduced the daily variation in neuronal activity: qsm(OX) led to a constitutive less active, night-like state, and qsm(RNAi) led to a more active, day-like state. Qsm also affected daily changes in K(+) currents and the GABA reversal potential, suggesting a role in modifying membrane currents and GABA responses in a daily fashion, potentially modulating light arousal and input to the clock. When directly challenged with blue light, wild-type l-LNvs responded with increased firing at night and no net response during the day, whereas altering Qsm, NKKC, or Shaw levels abolished these day/night differences. Finally, coexpression of Shaw(OX) and NKCC(RNAi) in a qsm mutant background restored LL-induced behavioral arrhythmicity and wild-type neuronal activity patterns, suggesting that the three genes operate in the same pathway. We propose that Qsm affects both daily and acute light effects in l-LNvs probably acting on Shaw and NKCC.

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  13. DNA damage and activated caspase-3 expression in neurons and astrocytes: evidence for apoptosis in frontotemporal dementia.

    PubMed

    Su, J H; Nichol, K E; Sitch, T; Sheu, P; Chubb, C; Miller, B L; Tomaselli, K J; Kim, R C; Cotman, C W

    2000-05-01

    Frontotemporal dementia (FTD) is a neurodegenerative disease which affects mainly the frontal and anterior temporal cortex. It is associated with neuronal loss, gliosis, and microvacuolation of lamina I to III in these brain regions. In previous studies we have described neurons with DNA damage in the absence of tangle formation and suggested this may result in tangle-independent mechanisms of neurodegeneration in the AD brain. In the present study, we sought to examine DNA fragmentation and activated caspase-3 expression in FTD brain where tangle formation is largely absent. The results demonstrate that numerous nuclei were TdT positive in all FTD brains examined. Activated caspase-3 immunoreactivity was detected in both neurons and astrocytes and was elevated in FTD cases as compared to control cases. A subset of activated caspase-3-positive cells were also TdT positive. In addition, the cell bodies of a subset of astrocytes showed enlarged, irregular shapes, and vacuolation and their processes appeared fragmented. These degenerating astrocytes were positive for activated caspase-3 and colocalized with robust TdT-labeled nuclei. These findings suggest that a subset of astrocytes exhibit degeneration and that DNA damage and activated caspase-3 may contribute to neuronal cell death and astrocyte degeneration in the FTD brain. Our results suggest that apoptosis may be a mechanism of neuronal cell death in FTD as well as in AD (228).

  14. Modifications of excitatory and inhibitory transmission in rat hippocampal pyramidal neurons by acute lithium treatment.

    PubMed

    Wakita, Masahito; Nagami, Hideaki; Takase, Yuko; Nakanishi, Ryoji; Kotani, Naoki; Akaike, Norio

    2015-08-01

    The acute effects of high-dose Li(+) treatment on glutamatergic and GABAergic transmissions were studied in the "synaptic bouton" preparation of isolated rat hippocampal pyramidal neurons by using focal electrical stimulation. Both action potential-dependent glutamatergic excitatory and GABAergic inhibitory postsynaptic currents (eEPSC and eIPSC, respectively) were dose-dependently inhibited in the external media containing 30-150 mM Li(+), but the sensitivity for Li(+) was greater tendency for eEPSCs than for eIPSCs. When the effects of Li(+) on glutamate or GABAA receptor-mediated whole-cell responses (IGlu and IGABA) elicited by an exogenous application of glutamate or GABA were examined in the postsynaptic soma membrane of CA3 neurons, Li(+) slightly inhibited both IGlu and IGABA at the 150 mM Li(+) concentration. Present results suggest that acute treatment with high concentrations of Li(+) acts preferentially on presynaptic terminals, and that the Li(+)-induced inhibition may be greater for excitatory than for inhibitory transmission.

  15. Temporal relationship of serum markers and tissue damage during acute intestinal ischemia/reperfusion

    PubMed Central

    la Garza, Francisco Javier Guzmán-de; Ibarra-Hernández, Juan Manuel; Cordero-Pérez, Paula; Villegas-Quintero, Pablo; Villarreal-Ovalle, Claudia Ivette; Torres-González, Liliana; Oliva-Sosa, Norma Edith; Alarcón-Galván, Gabriela; Fernández-Garza, Nancy Esthela; Muñoz-Espinosa, Linda Elsa; Cámara-Lemarroy, Carlos Rodrigo; Carrillo-Arriaga, José Gerardo

    2013-01-01

    OBJECTIVE: It is essential to identify a serological marker of injury in order to study the pathophysiology of intestinal ischemia reperfusion. In this work, we studied the evolution of several serological markers after intestinal ischemia reperfusion injury in rats. The markers of non-specific cell damage were aspartate aminotransferase, alanine aminotransaminase, and lactic dehydrogenase, the markers of inflammation were tumor necrosis factor alpha, interleukin-6, and interleukin-1 beta, and the markers of intestinal mucosal damage were intestinal fatty acid binding protein and D-lactate. We used Chiús classification to grade the histopathological damage. METHODS: We studied 35 Wistar rats divided into groups according to reperfusion time. The superior mesenteric artery was clamped for 30 minutes, and blood and biopsies were collected at 1, 3, 6, 12, 24, and 48 hours after reperfusion. We plotted the mean ± standard deviation and compared the baseline and maximum values for each marker using Student's t-test. RESULTS: The maximum values of interleukin-1 beta and lactic dehydrogenase were present before the maximal histopathological damage. The maximum tumor necrosis factor alpha and D-lactate expressions coincided with histopathological damage. Alanine aminotransaminase and aspartate aminotransferase had a maximum expression level that increased following the histopathological damage. The maximum expressions of interluken-6 and intestinal fatty acid binding protein were not significantly different from the Sham treated group. CONCLUSION: For the evaluation of injury secondary to acute intestinal ischemia reperfusion with a 30 minute ischemia period, we recommend performing histopathological grading, quantification of D-lactate, which is synthesized by intestinal bacteria and is considered an indicator of mucosal injury, and quantification of tumor necrosis factor alpha as indicators of acute inflammation three hours after reperfusion. PMID:23917671

  16. Neuronal damage in hippocampal subregions induced by various durations of transient cerebral ischemia in gerbils using Fluoro-Jade B histofluorescence.

    PubMed

    Yu, Dong-Kun; Yoo, Ki-Yeon; Shin, Bich Na; Kim, In Hye; Park, Joon Ha; Lee, Choong Hyun; Choi, Jung Hoon; Cho, Yong-Jun; Kang, Il-Jun; Kim, Young-Myeong; Won, Moo-Ho

    2012-02-09

    Although there are many studies on ischemic brain damage in the gerbil, which is a good model of transient cerebral ischemia, studies on neuronal damage according to the duration of ischemia-reperfusion (I-R) time are limited. We carried out neuronal damage in the gerbil hippocampus after various durations of I-R (5, 10, 15 and 20 min) using Fluoro-Jade B (F-J B, a maker for neuronal degeneration) histofluorescence as well as cresyl violet (CV) staining. The changes of CV positive ((+)) neurons were well detected in the hippocampal CA1 region, not in the other regions. F-J B histofluorescence staining showed apparent neuronal damage in all the hippocampal subregions. In the CA1, most of the pyramidal neurons of the stratum pyramidale (SP) were stained with F-J B (about 100/mm(2) in a section), and F-J B(+) neurons in the other ischemia-groups were not changed. In the CA2, a few F-J B(+) neurons were detected in the SP of the 5 min ischemia-group, and F-J B(+) neurons were gradually increased with the longer time of ischemia: in the 20 min ischemia-group, the mean number of F-J B(+) neurons was about 85/mm(2) in a section. In the CA3, some F-J B(+) neurons were observed only in the SP of the 20 min ischemia-group. In the dentate gyrus, some F-J B positive neurons were detected only in the polymorphic layer (PL) of the 5 min ischemia-group, and the number of F-J B(+) neurons were gradually increased with the longer ischemic time. Our findings indicate that F-J B histofluorescence showed a very high quality of neuronal damage in all the hippocampal subregions.

  17. TRF2 dysfunction elicits DNA damage responses associated with senescence in proliferating neural cells and differentiation of neurons.

    PubMed

    Zhang, Peisu; Furukawa, Katsutoshi; Opresko, Patricia L; Xu, Xiangru; Bohr, Vilhelm A; Mattson, Mark P

    2006-04-01

    Telomeres are specialized structures at the ends of chromosomes that consist of tandem repeats of the DNA sequence TTAGGG and several proteins that protect the DNA and regulate the plasticity of the telomeres. The telomere-associated protein TRF2 (telomeric repeat binding factor 2) is critical for the control of telomere structure and function; TRF2 dysfunction results in the exposure of the telomere ends and activation of ATM (ataxia telangiectasin mutated)-mediated DNA damage response. Recent findings suggest that telomere attrition can cause senescence or apoptosis of mitotic cells, but the function of telomeres in differentiated neurons is unknown. Here, we examined the impact of telomere dysfunction via TRF2 inhibition in neurons (primary embryonic hippocampal neurons) and mitotic neural cells (astrocytes and neuroblastoma cells). We demonstrate that telomere dysfunction induced by adenovirus-mediated expression of dominant-negative TRF2 (DN-TRF2) triggers a DNA damage response involving the formation of nuclear foci containing phosphorylated histone H2AX and activated ATM in each cell type. In mitotic neural cells DN-TRF2 induced activation of both p53 and p21 and senescence (as indicated by an up-regulation of beta-galactosidase). In contrast, in neurons DN-TRF2 increased p21, but neither p53 nor beta-galactosidase was induced. In addition, TRF2 inhibition enhanced the morphological, molecular and biophysical differentiation of hippocampal neurons. These findings demonstrate divergent molecular and physiological responses to telomere dysfunction in mitotic neural cells and neurons, indicate a role for TRF2 in regulating neuronal differentiation, and suggest a potential therapeutic application of inhibition of TRF2 function in the treatment of neural tumors.

  18. The role of parkin in the differential susceptibility of tuberoinfundibular and nigrostriatal dopamine neurons to acute toxicant exposure.

    PubMed

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

    2015-01-01

    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 24h 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 24h 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 24h 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.

  19. alpha2-Adrenoceptor-mediated potassium currents in acutely dissociated rat locus coeruleus neurones.

    PubMed

    Arima, J; Kubo, C; Ishibashi, H; Akaike, N

    1998-04-01

    1. The noradrenaline (NA)-activated response was investigated in neurones acutely dissociated from the rat locus coeruleus (LC) using nystatin-perforated, conventional whole-cell and inside-out patch recording modes under current- and voltage-clamp conditions. 2. Under current-clamp conditions, NA hyperpolarized the LC neurones, abolishing the spontaneous action potentials. In voltage-clamp studies, NA induced an inwardly rectifying K+ current (INA) in a concentration-dependent manner with a half-maximum effective concentration of 2.2 x 10(-7) M. 3. INA was mimicked by the alpha2-agonist UK14304 but was inhibited by either the alpha2B/alpha2C antagonist ARC239 or the alpha1- and alpha2B/alpha2C antagonist prazosin, suggesting the contribution of alpha2B/alpha2C adrenoceptors. 4. INA was inhibited by the intracellular application of GDPbetaS but fully activated by intracellular perfusion of GTPgammaS. 5. In the inside-out recording mode, the application of GTP to the cytoplasmic side of the patch membrane markedly enhanced the open probability of the NA-activated single channels which represented the inwardly rectifying properties. 6. These results indicate that the activation of alpha2B/alpha2C adrenoceptors coupled with GTP-binding protein directly activates the inwardly rectifying K+ currents in rat LC neurones, thus resulting in a decrease in the spontaneous firing activities.

  20. Visually guided whole cell patch clamp of mouse supraoptic nucleus neurons in cultured and acute conditions.

    PubMed

    Stachniak, Tevye J E; Bourque, Charles W

    2006-07-01

    Recent advances in neuronal culturing techniques have supplied a new set of tools for studying neural tissue, providing effective means to study molecular aspects of regulatory elements in the supraoptic nucleus of the hypothalamus (SON). To combine molecular biology techniques with electrophysiological recording, we modified an organotypic culture protocol to permit transfection and whole cell patch-clamp recordings from SON cells. Neonatal mouse brain coronal sections containing the SON were dissected out, placed on a filter insert in culture medium, and incubated for at least 4 days to allow attachment to the insert. The SON was identifiable using gross anatomical landmarks, which remained intact throughout the culturing period. Immunohistochemical staining identified both vasopressinergic and oxytocinergic cells present in the cultures, typically appearing in well-defined clusters. Whole cell recordings from these cultures demonstrated that certain properties of the neonatal mouse SON were comparable to adult mouse magnocellular neurons. SON neurons in both neonatal cultures and acute adult slices showed similar sustained outward rectification above -60 mV and action potential broadening during evoked activity. Membrane potential, input resistance, and rapidly inactivating potassium current density (IA) were reduced in the cultures, whereas whole cell capacitance and spontaneous synaptic excitation were increased, perhaps reflecting developmental changes in cell physiology that warrant further study. The use of the outlined organotypic culturing procedures will allow the study of such electrophysiological properties of mouse SON using whole cell patch-clamp, in addition to various molecular, techniques that require longer incubation times.

  1. Blood Aggravates Histological and Functional Damage after Acute Subdural Hematoma in Rats.

    PubMed

    Jussen, Daniel; Krenzlin, Harald; Papaioannou, Chrysostomos; Ens, Swetlana; Kempski, Oliver; Alessandri, Beat

    2017-02-15

    Acute subdural hematoma (ASDH) is associated with high morbidity and mortality. Whether the volume effect of the hematoma and increase of intracranial pressure (ICP) or the local effect of blood are responsible for this severe pathophysiology is unclear. Therefore, we compared subdural infusion of autologous blood and paraffin oil in a rat model of ASDH. In a histological study, we investigated the effects on acute ICP, cerebral perfusion pressure (CPP), cerebral blood flow (CBF), tissue oxygen changes, and brain damage at 2, 24, and 96 h post-infusion. Inflammatory reaction was analyzed by immuno-staining for microglia (ionized calcium binding adaptor molecule 1 [Iba1]) and activated astrocytes (glial fibrillary acidic protein [GFAP]). Besides acute ICP and CBF changes, we investigated the development of behavior (neuroscore and beamwalk test) for up to 4 days after injury in a behavioral study. Despite comparably increased ICP, there was a more pronounced lesion growth in the blood infusion group during the first 96 h. Further, there was an increased peri-lesional immunoreactive area of Iba1 and GFAP 96 h post-infusion, primarily in the blood infusion group, whereas hippocampal damage was comparable in both infusion groups. In the behavioral evaluation, paraffin-infused animals showed a better recovery, compared with the blood infusion group. In conclusion, comparable acute time-course of ICP, CPP, and CBF clearly indicates that the differences in lesion size, inflammatory reaction, and behavioral deficits after blood- and paraffin oil-induced ASDH are partially due to blood constituents. Therefore, current data suggest that subdural hematomas should be completely removed as quickly as possible; decompression alone may not be sufficient to prevent secondary brain damage.

  2. Proteasome inhibition induces DNA damage and reorganizes nuclear architecture and protein synthesis machinery in sensory ganglion neurons.

    PubMed

    Palanca, Ana; Casafont, Iñigo; Berciano, María T; Lafarga, Miguel

    2014-05-01

    Bortezomib is a reversible proteasome inhibitor used as an anticancer drug. However, its clinical use is limited since it causes peripheral neurotoxicity. We have used Sprague-Dawley rats as an animal model to investigate the cellular mechanisms affected by both short-term and chronic bortezomib treatments in sensory ganglia neurons. Proteasome inhibition induces dose-dependent alterations in the architecture, positioning, shape and polarity of the neuronal nucleus. It also produces DNA damage without affecting neuronal survival, and severe disruption of the protein synthesis machinery at the central cytoplasm accompanied by decreased expression of the brain-derived neurotrophic factor. As a compensatory or adaptive survival response against proteotoxic stress caused by bortezomib treatment, sensory neurons preserve basal levels of transcriptional activity, up-regulate the expression of proteasome subunit genes, and generate a new cytoplasmic perinuclear domain for protein synthesis. We propose that proteasome activity is crucial for controlling nuclear architecture, DNA repair and the organization of the protein synthesis machinery in sensory neurons. These neurons are primary targets of bortezomib neurotoxicity, for which reason their dysfunction may contribute to the pathogenesis of the bortezomib-induced peripheral neuropathy in treated patients.

  3. 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

  4. GnRH neuron firing and response to GABA in vitro depend on acute brain slice thickness and orientation.

    PubMed

    Constantin, Stephanie; Piet, Richard; Iremonger, Karl; Hwa Yeo, Shel; Clarkson, Jenny; Porteous, Robert; Herbison, Allan E

    2012-08-01

    The GnRH neurons exhibit long dendrites and project to the median eminence. The aim of the present study was to generate an acute brain slice preparation that enabled recordings to be undertaken from GnRH neurons maintaining the full extent of their dendrites or axons. A thick, horizontal brain slice was developed, in which it was possible to record from the horizontally oriented GnRH neurons located in the anterior hypothalamic area (AHA). In vivo studies showed that the majority of AHA GnRH neurons projected outside the blood-brain barrier and expressed c-Fos at the time of the GnRH surge. On-cell recordings compared AHA GnRH neurons in the horizontal slice (AHAh) with AHA and preoptic area (POA) GnRH neurons in coronal slices [POA coronal (POAc) and AHA coronal (AHAc), respectively]. AHAh GnRH neurons exhibited tighter burst firing compared with other slice orientations. Although α-Amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) excited GnRH neurons in all preparations, γ-aminobutyric acid (GABA) was excitatory in AHAc and POAc but inhibitory in AHAh slices. GABA(A) receptor postsynaptic currents were the same in AHAh and AHAc slices. Intriguingly, direct activation of GABA(A) or GABA(B) receptors respectively stimulated and inhibited GnRH neurons regardless of slice orientation. Subsequent experiments indicated that net GABA effects were determined by differences in the ratio of GABA(A) and GABA(B) receptor-mediated effects in "long" and "short" dendrites of GnRH neurons in the different slice orientations. These studies document a new brain slice preparation for recording from GnRH neurons with their extensive dendrites/axons and highlight the importance of GnRH neuron orientation relative to the angle of brain slicing in studying these neurons in vitro.

  5. Kinin-B2 Receptor Exerted Neuroprotection After Diisopropylfluorophosphate-induced Neuronal Damage

    PubMed Central

    Torres-Rivera, Wilmarie; Pérez, Dinely; Park, Keon-Young; Carrasco, Marimée; Platt, Manu O.; Eterović, Vesna A.; Ferchmin, Pedro A.; Ulrich, Henning; Martins, Antonio H.

    2013-01-01

    The kinin-B2 receptor (B2BKR) activated by its endogenous ligand bradykinin participates in various metabolic processes including control of arterial pressure and inflammation. Recently, functions for this receptor in brain development and protection against glutamate-provoked excitotoxicity have been proposed. Here, we report neuroprotective properties for bradykinin against organophosphate poisoning using acute hippocampal slices as an in vitro model. Following slice perfusion for 10 min with diisopropylfluorophosphate (DFP) to initiate the noxious stimulus, responses of pyramidal neurons upon an electric impulse were reduced to less than 30 % of control amplitudes. Effects on synaptic-elicited population spikes were reverted when preparations had been exposed to bradykinin 30 min after challenging with DFP. Accordingly, bradykinin-induced population spike recovery was abolished by HOE-140, a B2BKR antagonist. However, the kinin-B1 receptor (B1BKR) agonist Lys-des-Arg9-bradykinin, inducing phosphorylation of MEK/MAPK and cell death, abolished bradykinin-mediated neuroprotection, an effect, which was reverted by the ERK inhibitor PD98059. In agreement with pivotal B1BKR functions in this process, antagonism of endogenous B1BKR activity alone was enough for restoring population spike activity. On the other hand pralidoxime, an oxime, reactivating AChE after organophosphate poisoning, induced population spike recovery after DFP exposure in the presence of bradykinin and Lys-des-Arg9-bradykinin. Lys-des-Arg9-bradykinin did not revert protection exerted by pralidoxime, however when instead bradykinin and Ly-des-Arg9-bradykinin were superfused together, recovery of population spikes diminished. These findings again confirm the neuroprotective feature of bradykinin, which is, diminished by its endogenous metabolites, stimulating the B1BKR, providing a novel understanding of physiological roles of these receptors. PMID:23735753

  6. Mechanism investigation of dioscin against CCl4-induced acute liver damage in mice.

    PubMed

    Lu, Binan; Xu, Yousong; Xu, Lina; Cong, Xiaonan; Yin, Lianhong; Li, Hua; Peng, Jinyong

    2012-09-01

    The mechanisms of the ameliorating effects of dioscin against CCl(4) induced acute liver damage are investigated in this study. Dioscin significantly inhibited (p<0.01) the increases of serum ALT and AST activities compared with the CCl(4)-treated animals. The hepatic lipid peroxidation formation and, concentrations of TNF-α and IL-6 were also decreased. Liver histopathologic studies and a DNA laddering assay indicated that dioscin protected hepatocytes against CCl(4)-induced apoptosis and necrosis. Furthermore, dioscin decreased the protein expressions of Fas/FasL, increased Bcl-2/Bax ratio, inhibited the release of cytochrome c from mitochondrion to cytosol and attenuated CCl(4)-induced caspase-3 and -8 activities. The expressions of ICAM-1, vimentin, prohibitin, HGF, c-MET and GSTA1 were also regulated by dioscin and iNOS was also involved in the effects of this agent. These protective effects against CCl(4) induced acute liver damage might be through inhibiting lipid peroxidation, inflammatory cytokines, necrosis and apoptosis, and dioscin shows promise for development toward the treatment of acute chemically mediated liver injury.

  7. Erythrocyte membrane fluidity and indices of plasmatic oxidative damage after acute physical exercise in humans.

    PubMed

    Berzosa, C; Gómez-Trullén, E M; Piedrafita, E; Cebrián, I; Martínez-Ballarín, E; Miana-Mena, F J; Fuentes-Broto, L; García, J J

    2011-06-01

    Optimal levels of membrane fluidity are essential for numerous cell functions including cell growth, solute transport and signal transduction. Since exercise enhances free radical production, our aim was to evaluate in healthy male subjects the effects of an acute bout of maximal and submaximal exercise on the erythrocyte membrane fluidity and its possible relation to the oxidative damage overproduction due to exercise. Subjects (n = 34) performed three cycloergometric tests: a continuous progressive exercise, a strenuous exercise until exhaustion and an acute bout of exercise at an intensity corresponding to 70% of maximal work capacity for 30 min. Venous blood samples were collected before and immediately after these exercises. Erythrocyte membrane fluidity was assessed by fluorescence spectroscopy. Plasma malondialdehyde (MDA) and 4-hydroxyalkenals (4-HDA) concentrations and carbonyl content of plasmatic proteins were used as an index of lipid and protein oxidation, respectively. Exercise produced a dramatic drop in the erythrocyte membrane fluidity as compared to resting time, but this was not accompanied by significant changes in the plasmatic MDA and 4-HDA concentrations. The highest erythrocyte membrane rigidity was detected immediately after strenuous exercise until exhaustion was performed. Protein carbonyl levels were higher after exhaustive exercises than at rest. Continuous progressive and strenuous exercises until exhaustion, but not submaximal workload, resulted in a significant enhanced accumulation of carbonylated proteins in the plasma. These findings are consistent with the idea that exercise exaggerates oxidative damage, which may contribute, at least partially, to explain the rigidity in the membrane of the erythrocytes due to acute exercise.

  8. Cannabidiol reduces brain damage and improves functional recovery after acute hypoxia-ischemia in newborn pigs.

    PubMed

    Lafuente, Hector; Alvarez, Francisco J; Pazos, M Ruth; Alvarez, Antonia; Rey-Santano, M Carmen; Mielgo, Victoria; Murgia-Esteve, Xabier; Hilario, Enrique; Martinez-Orgado, José

    2011-09-01

    Newborn piglets exposed to acute hypoxia-ischemia (HI) received i.v. cannabidiol (HI + CBD) or vehicle (HI + VEH). In HI + VEH, 72 h post-HI brain activity as assessed by amplitude-integrated EEG (aEEG) had only recovered to 42 ± 9% of baseline, near-infrared spectroscopy (NIRS) parameters remained lower than normal, and neurobehavioral performance was abnormal (27.8 ± 2.3 points, normal 36). In the brain, there were fewer normal and more pyknotic neurons, while astrocytes were less numerous and swollen. Cerebrospinal fluid concentration of neuronal-specific enolase (NSE) and S100β protein and brain tissue percentage of TNFα(+) cells were all higher. In contrast, in HI + CBD, aEEG had recovered to 86 ± 5%, NIRS parameters increased, and the neurobehavioral score normalized (34.3 ± 1.4 points). HI induced histological changes, and NSE and S100β concentration and TNFα(+) cell increases were suppressed by CBD. In conclusion, post-HI administration of CBD protects neurons and astrocytes, leading to histological, functional, biochemical, and neurobehavioral improvements.

  9. Orexin-A suppresses postischemic glucose intolerance and neuronal damage through hypothalamic brain-derived neurotrophic factor.

    PubMed

    Harada, Shinichi; Yamazaki, Yui; Tokuyama, Shogo

    2013-01-01

    Orexin-A (a glucose-sensing neuropeptide in the hypothalamus) and brain-derived neurotrophic factor (BDNF; a member of the neurotrophin family) play roles in many physiologic functions, including regulation of glucose metabolism. We previously showed that the development of postischemic glucose intolerance is one of the triggers of ischemic neuronal damage. The aim of this study was to determine whether there was an interaction between orexin-A and BDNF functions in the hypothalamus after cerebral ischemic stress. Male ddY mice were subjected to 2 hours of middle cerebral artery occlusion (MCAO). Neuronal damage was estimated by histologic and behavioral analyses. Expression of protein levels was analyzed by Western blot. Small interfering RNA directed BDNF, orexin-A, and SB334867 [N-(2-methyl-6-benzoxazolyl)-N'-1,5-naphthyridin-4-yl urea; a specific orexin-1 receptor antagonist] were administered directly into the hypothalamus. The level of hypothalamic orexin-A, detected by immunohistochemistry, was decreased on day 1 after MCAO. Intrahypothalamic administration of orexin-A (1 or 5 pmol/mouse) significantly and dose-dependently suppressed the development of postischemic glucose intolerance on day 1 and development of neuronal damage on day 3. The MCAO-induced decrease in insulin receptor levels in the liver and skeletal muscle on day 1 was recovered to control levels by orexin-A, and this effect of orexin-A was reversed by the administration of SB334867 as well as by hypothalamic BDNF knockdown. These results suggest that suppression of postischemic glucose intolerance by orexin-A assists in the prevention of cerebral ischemic neuronal damage. In addition, hypothalamic BDNF may play an important role in this effect of orexin-A.

  10. MMP-3 contributes to nigrostriatal dopaminergic neuronal loss, BBB damage, and neuroinflammation in an MPTP mouse model of Parkinson's disease.

    PubMed

    Chung, Young Cheul; Kim, Yoon-Seong; Bok, Eugene; Yune, Tae Young; Maeng, Sungho; Jin, Byung Kwan

    2013-01-01

    The present study examined whether matrix metalloproteinase-3 (MMP-3) participates in the loss of dopaminergic (DA) neurons in the nigrostriatal pathway in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of Parkinson's disease with blood brain barrier (BBB) damage and infiltration of peripheral immune cells. Tyrosine hydroxylase (TH) immunostaining of brain sections from MPTP-treated mice showed that MPTP induced significant degeneration of nigrostriatal DA neurons. Moreover, FITC-labeled albumin detection and immunostaining revealed that MPTP caused damage to the BBB and increased the number of ED-1- and CD-3-immunopositive cells in the substantia nigra (SN). Genetic ablation of MMP-3 reduced the nigrostriatal DA neuron loss and improved motor function. This neuroprotective effect afforded by MMP-3 deletion was associated with the suppression of BBB disruption and a decrease in the number of ED-1- and CD-3-immunopositive cells in the SN. These data suggest that MMP-3 could play a crucial role in neurodegenerative diseases such as PD in which BBB damage and neuroinflammation are implicated.

  11. 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)

  12. Postsynaptic Receptors for Amyloid-β Oligomers as Mediators of Neuronal Damage in Alzheimer's Disease.

    PubMed

    Dinamarca, Margarita C; Ríos, Juvenal A; Inestrosa, Nibaldo C

    2012-01-01

    The neurotoxic effect of amyloid-β peptide (Aβ) over the central synapses has been described and is reflected in the decrease of some postsynaptic excitatory proteins, the alteration in the number and morphology of the dendritic spines, and a decrease in long-term potentiation. Many studies has been carried out to identify the putative Aβ receptors in neurons, and is still no clear why the Aβ oligomers only affect the excitatory synapses. Aβ oligomers bind to neurite and preferentially to the postsynaptic region, where the postsynaptic protein-95 (PSD-95) is present in the glutamatergic synapse, and interacts directly with the N-methyl-D-aspartate receptor (NMDAR) and neuroligin (NL). NL is a postsynaptic protein which binds to the presynaptic protein, neurexin to form a heterophilic adhesion complex, the disruption of this interaction affects the integrity of the synaptic contact. Structurally, NL has an extracellular domain homolog to acetylcholinesterase, the first synaptic protein that was found to interact with Aβ. In the present review we will document the interaction between Aβ and the extracellular domain of NL-1 at the excitatory synapse, as well as the interaction with other postsynaptic components, including the glutamatergic receptors (NMDA and mGluR5), the prion protein, the neurotrophin receptor, and the α7-nicotinic acetylcholine receptor. We conclude that several Aβ oligomers receptors exist at the excitatory synapse, which could be the responsible for the neurotoxic effect described for the Aβ oligomers. The characterization of the interaction between Aβ receptors and Aβ oligomers could help to understand the source of the neurologic damage observed in the brain of the Alzheimer's disease patients.

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

    PubMed Central

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

    2016-01-01

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

  14. Neuroprotective evaluation of Tilia americana and Annona diversifolia in the neuronal damage induced by intestinal ischemia.

    PubMed

    Angeles-López, Guadalupe E; González-Trujano, María Eva; Déciga-Campos, Myrna; Ventura-Martínez, Rosa

    2013-08-01

    Tilia americana and Annona diversifolia are plants widely distributed in Mexico and sold in markets for their medicinal properties on the central nervous system (CNS) including possible neuroprotection. Pharmacological studies have corroborated CNS activities due to flavonoid constituents, but evidence of their neuroprotector effects are lacking. This study was conducted to test aqueous and organic extracts of these two plants for neuroprotective effects in a novel experimental model of intestinal ischemia in situ. T. americana and A. diversifolia aqueous and organic extracts were administrated to guinea pigs at an oral dose of 100 and 300 mg/kg for 15 days. Twenty four hours after the last administration, the animals were anesthetized and intestinal ischemia in situ was induced by clamping for 80 min selected branches of the superior mesenteric artery. Ischemic segments placed in an in vitro organ bath were stimulated electrically (0.3 Hz frequency, 3.0 ms duration, 14 V intensity) and chemically (ACh; 1 × 10(-9) to 1×10(-5) M). Neuroprotection was considered present when the depressed contractile response of the ischemic tissue to electrical stimulation was normalized in the treated animals. Results showed that pretreatment with the T. americana hexane and aqueous extracts, but not with those from A. diversifolia, significantly improved responses of the ischemic tissue. These results suggest that T. americana possesses neuroprotective effects against neuronal damage induced by ischemia, and that flavonoids as well as non-polar constituents are involved. Our study supports the use of this plant in folk medicine and suggests its possible effectiveness for stroke prevention.

  15. Mitochondrial DNA damage and a hypoxic response are induced by CoCl2 in rat neuronal PC12 cells

    PubMed Central

    Wang, Guichun; Hazra, Tapas K.; Mitra, Sankar; Lee, Heung-Man; Englander, Ella W.

    2000-01-01

    Generation of reactive oxygen species (ROS) and activation of a transcriptional program that mimics the hypoxic response have been documented in cultured cells in the presence of cobalt chloride. We found that in the presence of hypoxia-mimicking concentrations of CoCl2, mitochondrial but not nuclear DNA damage is induced in rat neuronal, PC12 cells. To our knowledge, this is the first documentation of induction of mitochondrial DNA (mtDNA) damage under these conditions. Likewise, we provide the first evidence for elevation of MYH, the mammalian homolog of the Escherichia coli MutY DNA glycosylase, in mammalian cells. Recently, the human MYH was implicated in repair of oxidative DNA damage and shown to carry a mitochondrial localization sequence. Here, an induction of mtDNA damage and a time-dependent increase in the MYH level were detected with exposure of cells to 100 µM CoCl2. In addition, the levels of proteins involved in cellular responses to hypoxia, ROS and nuclear DNA damage; hypoxia-inducible factor 1α (HIF-1α), p53, p21 and PCNA were also modulated temporally. Earlier studies suggested that the mtDNA is a primary target for oxidative damage. Our findings extend these observations and suggest that activation of DNA repair processes is associated with the presence of mtDNA damage. PMID:10773083

  16. Mitochondrial DNA damage and a hypoxic response are induced by CoCl(2) in rat neuronal PC12 cells.

    PubMed

    Wang, G; Hazra, T K; Mitra, S; Lee, H M; Englander, E W

    2000-05-15

    Generation of reactive oxygen species (ROS) and activation of a transcriptional program that mimics the hypoxic response have been documented in cultured cells in the presence of cobalt chloride. We found that in the presence of hypoxia-mimicking concentrations of CoCl(2), mitochondrial but not nuclear DNA damage is induced in rat neuronal, PC12 cells. To our knowledge, this is the first documentation of induction of mitochondrial DNA (mtDNA) damage under these conditions. Likewise, we provide the first evidence for elevation of MYH, the mammalian homolog of the Escherichia coli MutY DNA glycosylase, in mammalian cells. Recently, the human MYH was implicated in repair of oxidative DNA damage and shown to carry a mitochondrial localization sequence. Here, an induction of mtDNA damage and a time-dependent increase in the MYH level were detected with exposure of cells to 100 microM CoCl(2). In addition, the levels of proteins involved in cellular responses to hypoxia, ROS and nuclear DNA damage; hypoxia-inducible factor 1alpha(HIF-1alpha), p53, p21 and PCNA were also modulated temporally. Earlier studies suggested that the mtDNA is a primary target for oxidative damage. Our findings extend these observations and suggest that activation of DNA repair processes is associated with the presence of mtDNA damage.

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2014-01-01

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

  19. Torsade de pointes indicates early neurologic damage in acute ischemic stroke.

    PubMed

    Huang, Li-Yen; Lin, Wei-Shiang; Lin, Wen-Yu; Cheng, Cheng-Chung; Cheng, Shu-Meng; Tsai, Tsung-Neng

    2013-12-01

    Torsade de pointes (TdP) is a life-threatening polymorphic ventricular tachycardia that is related to QT prolongation. Although QT prolongation is commonly seen in acute stroke, TdP is rare. We report the case of a 78-year-old woman with ischemic stroke who presented with TdP as the initial manifestation of early neurologic deterioration. We hypothesized that an increase in intracranial pressure may result in neurohormonal activation, QT prolongation, and then myocardial damage, leading to TdP. We highlight that new onset of TdP in a patient with stroke may reflect neurologic deterioration, requiring further evaluation and specific intervention.

  20. 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

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

    SciTech Connect

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

    2011-11-15

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

  2. 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

    2016-08-02

    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.

  3. Electrophysiological profile of the new atypical neuroleptic, sertindole, on midbrain dopamine neurones in rats: acute and repeated treatment.

    PubMed

    Skarsfeldt, T

    1992-01-01

    Sertindole (Lundbeck code No. Lu 23-174) (1-[2-[4-[5-chloro-1-(4-fluorophenyl)-1H-indol-3-yl]-1-piperidinyl] ethyl]-2-imidazolidinone) is a new potential neuroleptic compound. After 3 weeks of treatment sertindole shows an extreme selectivity to inhibit the number of spontaneously active dopaminergic (DA) neurones in ventral tegmental area (VTA) while leaving the number of active DA neurones in substantia nigra pars compacta (SNC) unaffected. Acute injection of apomorphine or baclofen reverse the inhibition of activity seen after repeated treatment with sertindole. This suggests that sertindole induces a depolarization inactivation of the DA neurones. The depolarization inactivation is reversible since normal activity of DA neurones is found in both SNC and VTA after two weeks withdrawal from repeated treatment with a low dose with sertindole. One or two weeks administration of a high dose of sertindole induced only minor effects on the DA neurones in VTA; i.e., in order to obtain the depolarization inactivation sertindole requires 3 weeks of treatment as has also been reported for other neuroleptics. Three weeks of treatment with clozapine induces a selective inhibition of the active DA neurones in VTA but at much higher doses than seen with sertindole, while haloperidol induces a non-selective decrease of spontaneously active DA neurones in both areas. In acute electrophysiological experiments intravenous (i.v.) administration of sertindole--in contrast to both clozapine and haloperidol--neither reverse d-amphetamine- nor apomorphine-induced inhibition of the firing frequencies of DA neurones in SNC or in VTA. In addition, sertindole does not--even in high doses--increase the firing frequency of DA neurones in SNC or VTA.(ABSTRACT TRUNCATED AT 250 WORDS)

  4. Characterization of strychnine-sensitive glycine receptors in acutely isolated adult rat basolateral amygdala neurons.

    PubMed

    McCool, B A; Botting, S K

    2000-03-24

    Large concentrations of the beta-amino acid, taurine, can be found in many forebrain areas such as the basolateral amygdala, a portion of the limbic forebrain intimately associated with the regulation of fear/anxiety-like behaviors. In addition to its cytoprotective and osmoregulatory roles, taurine may also serve as an agonist at GABA(A)- and strychnine-sensitive glycine receptors. In this latter context, the present study demonstrates that application of taurine to acutely isolated neurons from the basolateral amygdala of adult rats causes significant alterations in resting membrane current, as measured by whole-cell patch clamp electrophysiology. Using standard pharmacological approaches, we find that currents gated by concentrations of taurine neurons, these two chloride channels are functionally expressed at comparable levels. Given that a number of clinically relevant compounds are associated with the regulation of GABA(A) receptors in this brain region, the presence of both strychnine-sensitive glycine receptors and their agonist, taurine, in the basolateral amygdala may suggest an important role for these receptors in the limbic forebrain of adult rats.

  5. Potential Adverse Effects of Prolonged Sevoflurane Exposure on Developing Monkey Brain: From Abnormal Lipid Metabolism to Neuronal Damage

    PubMed Central

    Liu, Fang; Rainosek, Shuo W.; Frisch-Daiello, Jessica L.; Patterson, Tucker A.; Paule, Merle G.; Slikker, William; Wang, Cheng; Han, Xianlin

    2015-01-01

    Sevoflurane is a volatile anesthetic that has been widely used in general anesthesia, yet its safety in pediatric use is a public concern. This study sought to evaluate whether prolonged exposure of infant monkeys to a clinically relevant concentration of sevoflurane is associated with any adverse effects on the developing brain. Infant monkeys were exposed to 2.5% sevoflurane for 9 h, and frontal cortical tissues were harvested for DNA microarray, lipidomics, Luminex protein, and histological assays. DNA microarray analysis showed that sevoflurane exposure resulted in a broad identification of differentially expressed genes (DEGs) in the monkey brain. In general, these genes were associated with nervous system development, function, and neural cell viability. Notably, a number of DEGs were closely related to lipid metabolism. Lipidomic analysis demonstrated that critical lipid components, (eg, phosphatidylethanolamine, phosphatidylserine, and phosphatidylglycerol) were significantly downregulated by prolonged exposure of sevoflurane. Luminex protein analysis indicated abnormal levels of cytokines in sevoflurane-exposed brains. Consistently, Fluoro-Jade C staining revealed more degenerating neurons after sevoflurane exposure. These data demonstrate that a clinically relevant concentration of sevoflurane (2.5%) is capable of inducing and maintaining an effective surgical plane of anesthesia in the developing nonhuman primate and that a prolonged exposure of 9 h resulted in profound changes in gene expression, cytokine levels, lipid metabolism, and subsequently, neuronal damage. Generally, sevoflurane-induced neuronal damage was also associated with changes in lipid content, composition, or both; and specific lipid changes could provide insights into the molecular mechanism(s) underlying anesthetic-induced neurotoxicity and may be sensitive biomarkers for the early detection of anesthetic-induced neuronal damage. PMID:26206149

  6. Potential Adverse Effects of Prolonged Sevoflurane Exposure on Developing Monkey Brain: From Abnormal Lipid Metabolism to Neuronal Damage.

    PubMed

    Liu, Fang; Rainosek, Shuo W; Frisch-Daiello, Jessica L; Patterson, Tucker A; Paule, Merle G; Slikker, William; Wang, Cheng; Han, Xianlin

    2015-10-01

    Sevoflurane is a volatile anesthetic that has been widely used in general anesthesia, yet its safety in pediatric use is a public concern. This study sought to evaluate whether prolonged exposure of infant monkeys to a clinically relevant concentration of sevoflurane is associated with any adverse effects on the developing brain. Infant monkeys were exposed to 2.5% sevoflurane for 9 h, and frontal cortical tissues were harvested for DNA microarray, lipidomics, Luminex protein, and histological assays. DNA microarray analysis showed that sevoflurane exposure resulted in a broad identification of differentially expressed genes (DEGs) in the monkey brain. In general, these genes were associated with nervous system development, function, and neural cell viability. Notably, a number of DEGs were closely related to lipid metabolism. Lipidomic analysis demonstrated that critical lipid components, (eg, phosphatidylethanolamine, phosphatidylserine, and phosphatidylglycerol) were significantly downregulated by prolonged exposure of sevoflurane. Luminex protein analysis indicated abnormal levels of cytokines in sevoflurane-exposed brains. Consistently, Fluoro-Jade C staining revealed more degenerating neurons after sevoflurane exposure. These data demonstrate that a clinically relevant concentration of sevoflurane (2.5%) is capable of inducing and maintaining an effective surgical plane of anesthesia in the developing nonhuman primate and that a prolonged exposure of 9 h resulted in profound changes in gene expression, cytokine levels, lipid metabolism, and subsequently, neuronal damage. Generally, sevoflurane-induced neuronal damage was also associated with changes in lipid content, composition, or both; and specific lipid changes could provide insights into the molecular mechanism(s) underlying anesthetic-induced neurotoxicity and may be sensitive biomarkers for the early detection of anesthetic-induced neuronal damage.

  7. Phosphorylated tau potentiates Aβ-induced mitochondrial damage in mature neurons.

    PubMed

    Quintanilla, Rodrigo A; von Bernhardi, Rommy; Godoy, Juan A; Inestrosa, Nibaldo C; Johnson, Gail V W

    2014-11-01

    Tau phosphorylated at the PHF-1 epitope (S396/S404) is likely involved in the pathogenesis of Alzheimer's disease (AD). However, the molecular mechanisms by which tau phosphorylated at these sites negatively impacts neuronal functions are still under scrutiny. Previously, we showed that expression of tau truncated at D421 enhances mitochondrial dysfunction induced by Aβ in cortical neurons. To extend these findings, we expressed tau pseudo-phosphorylated at S396/404 (T42EC) in mature and young cortical neurons and evaluated different aspects of mitochondrial function in response to Aβ. Expression of T42EC did not induce significant changes in mitochondrial morphology, mitochondrial length, or mitochondrial transport, compared to GFP and full-length tau. However, T42EC expression enhanced Aβ-induced mitochondrial membrane potential loss and increased superoxide levels compared to what was observed in mature neurons expressing full-length tau. The same effect was observed in mature neurons that expressed both pseudo-phosphorylated and truncated tau when they were treated with Aβ. Interestingly, the mitochondrial failure induced by Aβ in mature neurons that expressed T42EC, was not observed in young neurons expressing T42EC. These novel findings suggest that phosphorylated tau (PHF-1 epitope) enhances Aβ-induced mitochondrial injury, which contributes to neuronal dysfunction and to the pathogenesis of AD.

  8. Tauroursodeoxycholic acid reduces endoplasmic reticulum stress, acinar cell damage, and systemic inflammation in acute pancreatitis.

    PubMed

    Seyhun, Ersin; Malo, Antje; Schäfer, Claus; Moskaluk, Christopher A; Hoffmann, Ralf-Thorsten; Göke, Burkhard; Kubisch, Constanze H

    2011-11-01

    In acute pancreatitis, endoplasmic reticulum (ER) stress prompts an accumulation of malfolded proteins inside the ER, initiating the unfolded protein response (UPR). Because the ER chaperone tauroursodeoxycholic acid (TUDCA) is known to inhibit the UPR in vitro, this study examined the in vivo effects of TUDCA in an acute experimental pancreatitis model. Acute pancreatitis was induced in Wistar rats using caerulein, with or without prior TUDCA treatment. UPR components were analyzed, including chaperone binding protein (BiP), phosphorylated protein kinase-like ER kinase (pPERK), X-box binding protein (XBP)-1, phosphorylated c-Jun NH(2)-terminal kinase (pJNK), CCAAT/enhancer binding protein homologues protein, and caspase 12 and 3 activation. In addition, pancreatitis biomarkers were measured, such as serum amylase, trypsin activation, edema formation, histology, and the inflammatory reaction in pancreatic and lung tissue. TUDCA treatment reduced intracellular trypsin activation, edema formation, and cell damage, while leaving amylase levels unaltered. The activation of myeloperoxidase was clearly reduced in pancreas and lung. Furthermore, TUDCA prevented caerulein-induced BiP upregulation, reduced XBP-1 splicing, and caspase 12 and 3 activation. It accelerated the downregulation of pJNK. In controls without pancreatitis, TUDCA showed cytoprotective effects including pPERK signaling and activation of downstream targets. We concluded that ER stress responses activated in acute pancreatitis are grossly attenuated by TUDCA. The chaperone reduced the UPR and inhibited ER stress-associated proapoptotic pathways. TUDCA has a cytoprotective potential in the exocrine pancreas. These data hint at new perspectives for an employment of chemical chaperones, such as TUDCA, in prevention of acute pancreatitis.

  9. Acute canine distemper encephalitis is associated with rapid neuronal loss and local immune activation.

    PubMed

    Rudd, Penny A; Bastien-Hamel, Louis-Etienne; von Messling, Veronika

    2010-04-01

    For most virus infections of the central nervous system (CNS), immune-mediated damage, the route of inoculation and death of infected cells all contribute to the pathology observed. To investigate the role of these factors in early canine distemper neuropathogenesis, we infected ferrets either intranasally or intraperitoneally with the neurovirulent canine distemper virus strain Snyder Hill. Regardless of the route of inoculation, the virus primarily targeted the olfactory bulb, brainstem, hippocampus and cerebellum, whereas only occasional foci were detected in the cortex. The infection led to widespread neuronal loss, which correlated with the clinical signs observed. Increased numbers of activated microglia, reactive gliosis and different pro-inflammatory cytokines were detected in the infected areas, suggesting that the presence and ultimate death of infected cells at early times after infection trigger strong local immune activation, despite the observed systemic immunosuppression.

  10. 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

  11. Single administration of soluble epoxide hydrolase inhibitor suppresses neuroinflammation and improves neuronal damage after cardiac arrest in mice.

    PubMed

    Taguchi, Noriko; Nakayama, Shin; Tanaka, Makoto

    2016-10-01

    Cardiac arrest (CA) causes ischemia-reperfusion injury in the whole body among victims. Especially in the brain, inflammation and neuronal cell death can lead to irreversible dysfunction. Our goal was to determine whether a single administration of soluble epoxide hydrolase inhibitor (AS2586144-CL) has a neuroprotective effect and decreases the inflammatory response after CA and cardiopulmonary resuscitation (CPR). Global cerebral ischemia was induced in male C57BL/6 mice with 8min of CA. Thirty minutes after recovery of spontaneous circulation, the mice were randomly assigned to three groups and administered AS2586144-CL: 1mg/kg (n=25), 10mg/kg (n=25), or 0mg/kg (vehicle, n=25). At 6 and 7 days after CA/CPR, behavioral tests were conducted and brains were removed for histological evaluation. Analysis of histological damage 7 days after CA/CPR revealed that 10mg/kg of AS2586144-CL protected neurons, and suppressed cytokine production and microglial migration into the hippocampus. Two hours after CA/CPR, 10mg/kg of AS2586144-CL suppressed serum tumor necrosis factor-α and hippocampal nuclear factor κB expression. Our data show that 10mg/kg of AS2586144-CL administered following CA/CPR suppresses inflammation and decreases neuronal damage.

  12. Indomethacin ameliorates trimethyltin-induced neuronal damage in vivo by attenuating oxidative stress in the dentate gyrus of mice.

    PubMed

    Huong, Nguyen Quynh; Nakamura, Yukary; Kuramoto, Nobuyuki; Yoneyama, Masanori; Nagashima, Reiko; Shiba, Tatsuo; Yamaguchi, Taro; Hasebe, Shigeru; Ogita, Kiyokazu

    2011-01-01

    The organotin trimethyltin (TMT) is well known to cause neuronal degeneration in the hippocampal dentate gyrus of mice. The first purpose of the present study was to examine whether the cyclooxygenase (COX) inhibitor indomethacin could ameliorate neuronal degeneration in the dentate gyrus of mice following TMT treatment in vivo. The systemic injection into mice of TMT at 2.8 mg/kg produced activation of endogenous caspase-3 and calpain, enhanced the gene expression of COX-1 and COX-2, activated microglial cells, and caused the formation of the lipid peroxidation product 4-hydroxynonenal in the hippocampus. Given at 12-h post-TMT treatment, the systemic injection of indomethacin (5 or 10 mg/kg, subcutaneously) significantly decreased the TMT-induced damage to neurons having active caspase-3 and single-stranded DNA in the dentate granule cell layer of the hippocampus. The results of the α-Fodrin degradation test revealed that the post-treatment with indomethacin was effective in attenuating TMT-induced activation of endogenous caspases and calpain in the hippocampus. In TMT-treated animals, interestingly, the post-treatment with indomethacin produced not only activation of microglial cells in the dentate gyrus but also the formation of 4-hydroxynonenal in the dentate granule cell layer. Taken together, our data suggest that COX inhibition by indomethacin ameliorated TMT-induced neuronal degeneration in the dentate gyrus by attenuating intensive oxidative stress.

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

    PubMed

    Miao, Ming-San; Guo, Lin; Li, Rui-Qi; Zhang, Xiao-Lei

    2016-03-01

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

  14. Protection from neuronal damage induced by combined oxygen and glucose deprivation in organotypic hippocampal cultures by glutamate receptor antagonists.

    PubMed

    Strasser, U; Fischer, G

    1995-07-31

    Organotypic hippocampal cultures were exposed to defined periods (30 and 60 min) of combined oxygen and glucose deprivation, mimicking transient ischemic conditions. The involvement of different glutamate receptors in individual hippocampal subfields (CA1, CA3 and dentate gyrus) was studied using antagonists of NMDA (dizocilpine) and AMPA/kainate receptors (CNQX and GYKI 52466). Staining with the fluorescent dye propidium iodide (PI) allowed detection of damaged cells. For quantitative determination of neuronal damage, fluorescence intensity was measured after a 22 h recovery period and was related to maximal fluorescence intensity measured after fixation and PI restaining of the cultures at the end of the experiment. Dizocilpine (10 microM), CNQX (100 microM) and GYKI 52466 (100 microM) provided complete protection in CA1, CA3 and dentate gyrus following the moderate ischemic insult, when the antagonists were present permanently. This indicates that none of the ionotropic glutamate receptor subtypes dominated toxicity in the most sensitive subpopulation of neurons. When applied only during the recovery period protection with dizocilpine (10 microM) or CNQX (100 microM) was drastically reduced by about 60% in the most sensitive area (CA1), but only slightly by 15% in CA3. Therefore the onset of irreversible damage seems to occur earlier in CA1 than in CA3. Blockade of AMPA/kainate receptors by GYKI 52466 (100 microM) offered no neuroprotection if the compound was applied only during the recovery period.(ABSTRACT TRUNCATED AT 250 WORDS)

  15. Electrophysiological and Morphological Characterization of Neuronal Microcircuits in Acute Brain Slices Using Paired Patch-Clamp Recordings

    PubMed Central

    Qi, Guanxiao; Radnikow, Gabriele; Feldmeyer, Dirk

    2015-01-01

    The combination of patch clamp recordings from two (or more) synaptically coupled neurons (paired recordings) in acute brain slice preparations with simultaneous intracellular biocytin filling allows a correlated analysis of their structural and functional properties. With this method it is possible to identify and characterize both pre- and postsynaptic neurons by their morphology and electrophysiological response pattern. Paired recordings allow studying the connectivity patterns between these neurons as well as the properties of both chemical and electrical synaptic transmission. Here, we give a step-by-step description of the procedures required to obtain reliable paired recordings together with an optimal recovery of the neuron morphology. We will describe how pairs of neurons connected via chemical synapses or gap junctions are identified in brain slice preparations. We will outline how neurons are reconstructed to obtain their 3D morphology of the dendritic and axonal domain and how synaptic contacts are identified and localized. We will also discuss the caveats and limitations of the paired recording technique, in particular those associated with dendritic and axonal truncations during the preparation of brain slices because these strongly affect connectivity estimates. However, because of the versatility of the paired recording approach it will remain a valuable tool in characterizing different aspects of synaptic transmission at identified neuronal microcircuits in the brain. PMID:25650985

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

    SciTech Connect

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

    1994-05-01

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

  17. Ovarian hormone deficiency reduces intrinsic excitability and abolishes acute estrogen sensitivity in hippocampal CA1 pyramidal neurons

    PubMed Central

    Wu, Wendy W.; Adelman, John P.; Maylie, James

    2011-01-01

    Premature and uncompensated loss of ovarian hormones following ovariectomy (OVX) elevates the risks of cognitive impairment and dementia. These risks are prevented with estrogen (E2)-containing hormone replacement therapy initiated shortly following OVX but not after substantial delay. Currently the cellular bases underlying these clinical findings are unknown. At the cellular level, intrinsic membrane properties regulate the efficiency of synaptic inputs to initiate output action potentials (APs), thereby affecting neuronal communication hence cognitive processing. This study tested the hypothesis that in CA1 pyramidal neurons, intrinsic membrane properties and their acute regulation by E2 require ovarian hormones for maintenance. Whole-cell current clamp recordings were performed on neurons from ~7 months old OVX rats that experienced either short-term (10 days, control OVX) or long-term (5 months, OVXLT) ovarian hormone deficiency. The results reveal that long-term hormone deficiency reduced intrinsic membrane excitability (IE) as measured by the number of evoked action potentials (APs) and firing duration for a given current injection. This was accompanied by AP broadening, an increased slow afterhyperpolarization (sAHP), and faster accumulation of NaV channel inactivation during repetitive firing. In the control OVX neurons, E2 acutely increased IE and reduced the sAHP. In contrast, acute regulation of IE by E2 was absent in the OVXLT neurons. Since the degree of IE of hippocampal pyramidal neurons is positively related with hippocampus-dependent learning ability, and modulation of IE is observed following successful learning, these findings provide a framework for understanding hormone deficiency-related cognitive impairment and the critical window for therapy initiation. PMID:21325532

  18. Genome-Wide Expression Analysis Reveals Diverse Effects of Acute Nicotine Exposure on Neuronal Function-Related Genes and Pathways

    PubMed Central

    Wang, Ju; Cui, Wenyan; Wei, Jinxue; Sun, Dongxiao; Gutala, Ramana; Gu, Jun; Li, Ming D.

    2011-01-01

    Previous human and animal studies demonstrate that acute nicotine exposure has complicated influences on the function of the nervous system, which may lead to long-lasting effects on the behavior and physiology of the subject. To determine the genes and pathways that might account for long-term changes after acute nicotine exposure, a pathway-focused oligoarray specifically designed for drug addiction research was used to assess acute nicotine effect on gene expression in the neuron-like SH-SY5Y cells. Our results showed that 295 genes involved in various biological functions were differentially regulated by 1 h of nicotine treatment. Among these genes, the expression changes of 221 were blocked by mecamylamine, indicating that the majority of nicotine-modulated genes were altered through the nicotinic acetylcholine receptors (nAChRs)-mediated signaling process. We further identified 14 biochemical pathways enriched among the nicotine-modulated genes, among which were those involved in neural development/synaptic plasticity, neuronal survival/death, immune response, or cellular metabolism. In the genes significantly regulated by nicotine but blocked by mecamylamine, 13 enriched pathways were detected. Nine of these pathways were shared with those enriched in the genes regulated by nicotine, including neuronal function-related pathways such as glucocorticoid receptor signaling, p38 MAPK signaling, PI3K/AKT signaling, and PTEN signaling, implying that nAChRs play important roles in the regulation of these biological processes. Together, our results not only provide insights into the mechanism underlying the acute response of neuronal cells to nicotine but also provide clues to how acute nicotine exposure exerts long-term effects on the nervous system. PMID:21556275

  19. Interleukin-1beta but not tumor necrosis factor-alpha potentiates neuronal damage by quinolinic acid: protection by an adenosine A2A receptor antagonist.

    PubMed

    Stone, Trevor W; Behan, Wilhelmina M H

    2007-04-01

    Quinolinic acid is an agonist at glutamate receptors sensitive to N-methyl-D-aspartate (NMDA). It has been implicated in neural dysfunction associated with infections, trauma, and ischemia, although its neurotoxic potency is relatively low. This study was designed to examine the effects of a combination of quinolinic acid and the proinflammatory cytokines interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha). Compounds were administered to the hippocampus of anesthetized male rats, animals being allowed to recover for 7 days before histological analysis of the hippocampus for neuronal damage estimated by counting of intact, healthy neurons. A low dose of quinolinic acid or IL-1beta produced no damage by itself, but the two together induced a significant loss of pyramidal neurons in the hippocampus. Higher doses produced almost total loss of pyramidal cells. Intrahippocampal TNF-alpha produced no effect alone but significantly reduced the neuronal loss produced by quinolinic acid. The adenosine A(2A) receptor antagonist ZM241385 reduced neuronal loss produced by the combinations of quinolinic acid and IL-1beta. The results suggest that simultaneous quinolinic acid and IL-1beta, both being induced by cerebral infection or injury, are synergistic in the production of neuronal damage and could together contribute substantially to traumatic, infective, or ischemic cerebral damage. Antagonism of adenosine A(2A) receptors protects neurons against the combination of quinolinic acid and IL-1beta.

  20. Astrocyte-conditioned medium protecting hippocampal neurons in primary cultures against corticosterone-induced damages via PI3-K/Akt signal pathway.

    PubMed

    Zhu, Ze-Hua; Yang, Ru; Fu, Xin; Wang, Yan-Qing; Wu, Gen-Cheng

    2006-10-09

    Prolonged or excessive exposure to corticosterone leads to neuronal damages in the brain regions, including hippocampus. We reported that astrocyte-conditioned medium (ACM) protected the neurons of the primary hippocampal cultures against the corticosterone-induced damages. Corticosterone added to the cultures resulted in a significant number of TUNEL-positive cells. However, corticosterone-induced TUNEL labeling was suppressed as for ACM-cultured neurons. To delineate the molecular basis underlying the neuroprotection of ACM, we assessed the activation of ERK1/2 and (PI3-K)/Akt signal pathways in response to corticosterone-induced neuronal damages. Western blot test revealed that corticosterone increased the phosphorylation of ERK1/2 and PI3-K/Akt in hippocampal neurons grown in Neurobasal medium supplemented with B27 and 500 microm L-glutamine (NBM+). Interestingly, the increase of phospho-ERK1/2 and Akt levels was much pronounced and the time course of phosphorylation was altered in ACM, suggesting that both signaling pathways might participate in ACM protection. Furthermore, the selective inhibitor of Akt, rather than ERK1/2, blocked the neuroprotective activity against corticosterone in ACM-cultured neurons. In summary, our data showed that ACM had a potent neuroprotective effect in cultured neurons. PI3-K/Akt signal pathway, but not ERK1/2, was involved in the protective activity against the corticosterone-induced damages.

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

    PubMed Central

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

    2016-01-01

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

  2. Abnormal mitochondrial dynamics, mitochondrial loss and mutant huntingtin oligomers in Huntington's disease: implications for selective neuronal damage

    PubMed Central

    Shirendeb, Ulziibat; Reddy, Arubala P.; Manczak, Maria; Calkins, Marcus J.; Mao, Peizhong; Tagle, Danilo A.; Hemachandra Reddy, P.

    2011-01-01

    The purpose of our study was to determine the relationship between mutant huntingtin (Htt) and mitochondrial dynamics in the progression of Huntington's disease (HD). We measured the mRNA levels of electron transport chain genes, and mitochondrial structural genes, Drp1 (dynamin-related protein 1), Fis1 (fission 1), Mfn1 (mitofusin 1), Mfn2 (mitofusin 2), Opa1 (optric atrophy 1), Tomm40 (translocase of outermembrane 40) and CypD (cyclophilin D) in grade III and grade IV HD patients and controls. The mutant Htt oligomers and the mitochondrial structural proteins were quantified in the striatum and frontal cortex of HD patients. Changes in expressions of the electron transport chain genes were found in HD patients and may represent a compensatory response to mitochondrial damage caused by mutant Htt. Increased expression of Drp1 and Fis1 and decreased expression of Mfn1, Mfn2, Opa1 and Tomm40 were found in HD patients relative to the controls. CypD was upregulated in HD patients, and this upregulation increased as HD progressed. Significantly increased immunoreactivity of 8-hydroxy-guanosine was found in the cortical specimens from stage III and IV HD patients relative to controls, suggesting increased oxidative DNA damage in HD patients. In contrast, significantly decreased immunoreactivities of cytochrome oxidase 1 and cytochrome b were found in HD patients relative to controls, indicating a loss of mitochondrial function in HD patients. Immunoblotting analysis revealed 15, 25 and 50 kDa mutant Htt oligomers in the brain specimens of HD patients. All oligomeric forms of mutant Htt were significantly increased in the cortical tissues of HD patients, and mutant Htt oligomers were found in the nucleus and in mitochondria. The increase in Drp1, Fis1 and CypD and the decrease in Mfn1 and Mfn2 may be responsible for abnormal mitochondrial dynamics that we found in the cortex of HD patients, and may contribute to neuronal damage in HD patients. The presence of mutant Htt

  3. Abnormal mitochondrial dynamics, mitochondrial loss and mutant huntingtin oligomers in Huntington's disease: implications for selective neuronal damage.

    PubMed

    Shirendeb, Ulziibat; Reddy, Arubala P; Manczak, Maria; Calkins, Marcus J; Mao, Peizhong; Tagle, Danilo A; Reddy, P Hemachandra

    2011-04-01

    The purpose of our study was to determine the relationship between mutant huntingtin (Htt) and mitochondrial dynamics in the progression of Huntington's disease (HD). We measured the mRNA levels of electron transport chain genes, and mitochondrial structural genes, Drp1 (dynamin-related protein 1), Fis1 (fission 1), Mfn1 (mitofusin 1), Mfn2 (mitofusin 2), Opa1 (optric atrophy 1), Tomm40 (translocase of outermembrane 40) and CypD (cyclophilin D) in grade III and grade IV HD patients and controls. The mutant Htt oligomers and the mitochondrial structural proteins were quantified in the striatum and frontal cortex of HD patients. Changes in expressions of the electron transport chain genes were found in HD patients and may represent a compensatory response to mitochondrial damage caused by mutant Htt. Increased expression of Drp1 and Fis1 and decreased expression of Mfn1, Mfn2, Opa1 and Tomm40 were found in HD patients relative to the controls. CypD was upregulated in HD patients, and this upregulation increased as HD progressed. Significantly increased immunoreactivity of 8-hydroxy-guanosine was found in the cortical specimens from stage III and IV HD patients relative to controls, suggesting increased oxidative DNA damage in HD patients. In contrast, significantly decreased immunoreactivities of cytochrome oxidase 1 and cytochrome b were found in HD patients relative to controls, indicating a loss of mitochondrial function in HD patients. Immunoblotting analysis revealed 15, 25 and 50 kDa mutant Htt oligomers in the brain specimens of HD patients. All oligomeric forms of mutant Htt were significantly increased in the cortical tissues of HD patients, and mutant Htt oligomers were found in the nucleus and in mitochondria. The increase in Drp1, Fis1 and CypD and the decrease in Mfn1 and Mfn2 may be responsible for abnormal mitochondrial dynamics that we found in the cortex of HD patients, and may contribute to neuronal damage in HD patients. The presence of mutant Htt

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-11-15

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

  6. Acute neurotoxic effects of mancozeb and maneb in mesencephalic neuronal cultures are associated with mitochondrial dysfunction.

    PubMed

    Domico, Lisa M; Zeevalk, Gail D; Bernard, Laura P; Cooper, Keith R

    2006-09-01

    Recent studies suggest that exposure to agrochemicals may contribute to the development of idiopathic Parkinson's disease. Maneb (MB), a widely used Mn-containing ethylene-bis-dithiocarbamate (EBDC) fungicide, has been implicated in selective dopaminergic neurotoxicity. In this study, we examine the potential neurotoxicity of mancozeb (MZ), a widely used EBDC fungicide that is structurally similar to MB, but contains both Zn and Mn. Primary mesencephalic cells isolated from Sprague-Dawley embryonic day 15 rat embryos were exposed in vitro to either MZ or MB to compare their cytotoxic potential. Exposure to 10-120 microM MZ or MB for 24h resulted in a dose-dependent toxicity in both the dopamine (DA) and GABA mesencephalic populations as assessed by a functional assay for high affinity transporter activity. Consistent with this, cell viability as well as tyrosine hydroxylase-positive neurons decreased with increasing doses of MZ or MB. Toxic potencies for MZ and MB were similar and no difference in sensitivity between the DA and GABA populations was observed with the fungicides. Exposure to ethylene thiourea, the major metabolite of either MZ or MB, was not toxic, implicating the parent compound in toxicity. Both the organic and Mn metal components of the fungicides were found to contribute to toxicity. Non-toxic exposures to the fungicides decreased ATP levels in a dose-dependent manner suggesting impairment of energy metabolism. In whole mitochondrial preparations isolated from adult rat brains, MZ and MB inhibited NADH-linked state 3 respiration. Mild to moderate mitochondrial uncoupling was also observed in response to the fungicides. In conclusion, our findings indicate that acute exposure to high doses of MZ and MB produce equipotent toxic effects in both DA and GABA neurons that may be associated with perturbations in mitochondrial respiration.

  7. Striatal Dysfunctions Associated with Mitochondrial DNA Damage in Dopaminergic Neurons in a Mouse Model of Parkinson’s Disease

    PubMed Central

    Pickrell, Alicia M.; Pinto, Milena; Hida, Aline; Moraes, Carlos T.

    2012-01-01

    Parkinson’s disease (PD) is one of the most common progressive neurodegenerative disorders, characterized by resting tremor, rigidity, bradykinesia, and postural instability. These symptoms are associated with massive loss of tyrosine hydroxylase-positive neurons in the substantia nigra (SN) causing an estimated 70–80% depletion of dopamine (DA) in the striatum, where their projections are located. Although the etiology of PD is unknown, mitochondrial dysfunctions have been associated with the disease pathophysiology. We used a mouse model expressing a mitochondria-targeted restriction enzyme, PstI or mito-PstI, to damage mitochondrial DNA (mtDNA) in dopaminergic neurons. The expression of mito-PstI induces double-strand breaks in the mtDNA, leading to an oxidative phosphorylation deficiency, mostly due to mtDNA depletion. Taking advantage of a dopamine transporter (DAT) promoter-driven tetracycline transactivator protein (tTA), we expressed mito-PstI exclusively in dopaminergic neurons, creating a novel PD transgenic mouse model (PD-mito-PstI mouse). These mice recapitulate most of the major features of PD: they have a motor phenotype that is reversible with l-DOPA treatment, a progressive neurodegeneration of the SN dopaminergic population, and striatal DA depletion. Our results also showed that behavioral phenotypes in PD-mito-PstI mice were associated with striatal dysfunctions preceding SN loss of tyrosine hydroxylase-positive neurons and that other neurotransmitter systems [noradrenaline (NE) and serotonin (5-HT)] were increased after the disruption of DA neurons, potentially as a compensatory mechanism. This transgenic mouse model provides a novel model to study the role of mitochondrial defects in the axonal projections of the striatum in the pathophysiology of PD. PMID:22131425

  8. Acute O 3 damage on first year coppice sprouts of aspen and maple sprouts in an open-air experiment.

    PubMed

    Darbah, Joseph N T; Jones, Wendy S; Burton, Andrew J; Nagy, John; Kubiske, Mark E

    2011-09-01

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

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

    SciTech Connect

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

    2011-10-01

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

  10. Induction of neuronal damage in guinea pig brain by intratracheal infusion of 2-chloroethyl ethyl sulfide, a mustard gas analog.

    PubMed

    Gadsden-Gray, Jessica; Mukherjee, Shyamali; Ogunkua, Olugbemiga; Das, Salil K

    2012-01-01

    Intratracheal infusion of 2-chloroethyl ethyl sulfide (CEES), a mustard gas analog and a chemical warfare agent is known to cause massive damage to lung. The purpose of this study was to determine whether intratracheal CEES infusion causes neuronal damage. Histological, immunohistochemical, and Western blot studies indicated that CEES treatment caused dose-dependent increases in blood cell aggregation, microglial cell number, microglial activation, and brain inflammation. In addition, an increased expression of α-synuclein and a decreased expression of the dopamine transporter were observed. The results indicate that intratracheal CEES infusion is associated with changes in brain morphology mediated by an increase in α-synuclein expression, leading to neurotoxicity in a guinea pig model. These changes may be mediated by oxidative stress. Furthermore, the present study indicates for the first time that intratracheal infusion of a single dose of CEES can cause neuroinflammation, which may lead to neurological disorders in later part of life.

  11. Examination of the influence of leptin and acute metabolic challenge on RFRP-3 neurons of mice in development and adulthood

    PubMed Central

    Poling, Matthew C.; Shieh, Morris P.; Munaganuru, Nagambika; Luo, Elena; Kauffman, Alexander S.

    2014-01-01

    Background The neuropeptide RFamide-related peptide-3 (RFRP-3; mammalian ortholog to GnIH) can inhibit LH release and increases feeding, but the regulation and development of RFRP-3 neurons remains poorly characterized, especially in mice. Methods and Results We first confirmed that peripheral injections of murine RFRP-3 peptide could markedly suppress luteinizing hormone secretion in adult mice, as in other species. Second, given RFRP-3′s reported orexigenic properties, we performed double-label in situ hybridization for metabolic genes in Rfrp neurons of mice. While Rfrp neurons did not readily co-express NPY, TRH, or MC4R, a small subset of Rfrp neurons did express leptin receptor in both sexes. Surprisingly, we identified no changes in Rfrp expression or neuronal activation in adult mice after acute fasting. However, we determined that Rfrp mRNA levels in the DMN were significantly reduced in adult Obese (Ob) mice of both sexes. Given the lower Rfrp levels observed in adult Ob mice, we asked whether leptin might also regulate RFRP-3 neuron development. Rfrp gene expression changed markedly over juvenile development, correlating with the timing of the juvenile “leptin surge” known to govern hypothalamic feeding circuit development. However, the dramatic developmental changes in juvenile Rfrp expression did not appear to be leptin-driven, as the pattern and timing of Rfrp neuron development were unaltered in Ob juveniles. Conclusion Leptin status modulates RFRP-3 expression in adulthood, but is not required for normal development of the RFRP-3 system. Leptin's regulation of adult RFRP-3 neurons likely occurs via primarily indirect signaling, and may be secondary to obesity, as only a small subset of RFRP-3 neurons express LepRb. PMID:25378037

  12. Influences of nanoparticle zinc oxide on acutely isolated rat hippocampal CA3 pyramidal neurons.

    PubMed

    Zhao, Jingxia; Xu, Lanju; Zhang, Tao; Ren, Guogang; Yang, Zhuo

    2009-03-01

    The effects of zinc oxide nanoparticles (nano-ZnO) on the properties of voltage-dependent sodium, potassium currents and evoked action potentials were studied in acutely isolated rat hippocampal CA3 pyramidal neurons at postnatal ages of 10-14 days rats using the whole-cell patch-clamp technique. The results indicated that: (1) in the present of final concentration of 10(-4)g/ml nano-ZnO, the current-voltage curve of sodium current (I(Na)) was decreased, and the peak amplitudes of I(Na) were increased considerably from -50 to +20mV (p<0.05). Meanwhile, the inactivation and the recovery from inactivation of I(Na) were also promoted by the nano-ZnO solution (10(-4)g/ml) (p<0.01). However, the steady-state activation curve of I(Na) was not shifted by the nano-ZnO. (2) The amplitudes of transient outward potassium current (I(A)) were increased by the nano-ZnO solution (10(-4)g/ml), while the current-voltage curve of delayed rectifier potassium current (I(K)) was significantly increased from +20 to +90mV (p<0.05). However, it is apparent that the nano-ZnO solution did not shift the steady-state activation curve of I(A) and I(K), and neither had significant effects on the inactivation and the recovery from inactivation of I(A). (3) Peak amplitude and overshoot of the evoked single action potential were increased and half-width was diminished in the presence of the 10(-4)g/ml nano-ZnO solution (p<0.05). Simultaneously, a prolonged depolarizing current injection enhanced (p<0.05) repetitive firing evoked firing rate. These results suggested that 10(-4)g/ml nano-ZnO solution can lead to an enhancement in the current amplitudes of I(Na) and I(K) by increasing the opening number of sodium channels, delaying rectifier potassium channels, and enhancing the excitability of neurons, which lead to Na(+) influx and the accumulation of intracellular Na(+), as well as K(+) efflux plus the loss of cytoplasmic K(+). These may disturb the ionic homeostasis and the physiological

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

    PubMed Central

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

    2015-01-01

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

  14. Acute DNA damage activates the tumour suppressor p53 to promote radiation-induced lymphoma

    PubMed Central

    Lee, Chang-Lung; Castle, Katherine D.; Moding, Everett J.; Blum, Jordan M.; Williams, Nerissa; Luo, Lixia; Ma, Yan; Borst, Luke B.; Kim, Yongbaek; Kirsch, David G.

    2015-01-01

    Genotoxic cancer therapies, such as chemoradiation, cause haematological toxicity primarily by activating the tumour suppressor p53. While inhibiting p53-mediated cell death during cancer therapy ameliorates haematologic toxicity, whether it also impacts carcinogenesis remains unclear. Here we utilize a mouse model of inducible p53 short hairpin RNA (shRNA) to show that temporarily blocking p53 during total-body irradiation (TBI) not only ameliorates acute toxicity, but also improves long-term survival by preventing lymphoma development. Using KrasLA1 mice, we show that TBI promotes the expansion of a rare population of thymocytes that express oncogenic KrasG12D. However, blocking p53 during TBI significantly suppresses the expansion of KrasG12D-expressing thymocytes. Mechanistically, bone marrow transplant experiments demonstrate that TBI activates p53 to decrease the ability of bone marrow cells to suppress lymphoma development through a non-cell-autonomous mechanism. Together, our results demonstrate that the p53 response to acute DNA damage promotes the development of radiation-induced lymphoma. PMID:26399548

  15. Exploring psychotic symptoms: a comparison of motor related neuronal activation during and after acute psychosis

    PubMed Central

    2012-01-01

    Background Delusions and hallucinations are classic positive symptoms of schizophrenia. A contemporary cognitive theory called the ‘forward output model’ suggests that the misattribution of self-generated actions may underlie some of these types of symptoms, such as delusions of control – the experience of self-generated action being controlled by an external agency. In order to examine the validity of this suggestion, we performed a longitudinal functional magnetic resonance imaging (fMRI) study examining neuronal activation associated with motor movement during acute psychosis. Methods We studied brain activation using fMRI during a motor task in 11 patients with schizophrenia and 9 healthy controls. The patient group was tested at two time points separated by 6–8 weeks. Results At initial testing, the patient group had a mean Positive and Negative Syndrome Scale score of 56.3, and showed significantly increased activation within the left inferior parietal lobe (IPL) compared to controls. Patients reported significantly decreased positive symptoms at 6–8 week followup and IPL activation had returned to normal. Our results demonstrate that first-rank positive symptoms are associated with hyperactivation in the secondary somatosensory cortex (IPL). Conclusions These findings lend further credence to the theory that a dysfunction in the sensory feedback system located in the IPL, and which is thought to underlie our sense of agency, may contribute to the aetiology of delusions of control. PMID:22871335

  16. Acute intravenous administration of dietary constituent theanine suppresses noxious neuronal transmission of trigeminal spinal nucleus caudalis in rats.

    PubMed

    Takehana, Shiori; Kubota, Yoshiko; Uotsu, Nobuo; Yui, Kei; Shimazu, Yoshihito; Takeda, Mamoru

    2017-03-15

    Theanine is a non-dietary amino acid linked to the modulation of synaptic transmission in the central nervous system, although the acute effects of theanine in vivo, particularly on nociceptive transmission in the trigeminal system, remain to be determined. The present study investigated whether acute intravenous theanine administration to rats attenuates the excitability of wide dynamic range (WDR) spinal trigeminal nucleus caudalis (SpVc) neurons in response to nociceptive and non-nociceptive mechanical stimulation in vivo. Extracellular single unit recordings were made from 15 SpVc neurons in response to orofacial mechanical stimulation of pentobarbital-anesthetized rats, and responses to non-noxious and noxious mechanical stimuli were analyzed. The mean firing frequency of SpVc WDR neurons in response to all mechanical stimuli was dose-dependently inhibited by theanine (10, 50, and 100mM, i.v.) with the maximum inhibition of discharge frequency reached within 5min. These inhibitory effects were reversed after approximately 10min. The relative magnitude of theanine's inhibition of SpVc WDR neuronal discharge frequency was significantly greater for noxious than non-noxious stimulation. Iontophoretic application of l-glutamate induced the mean firing frequency of SpVc WDR neuron responding to noxious mechanical stimulation was also inhibited by intravenous administration of 100mM theanine. These results suggest that acute intravenous theanine administration suppresses glutaminergic noxious synaptic transmission in the SpVc, implicating theanine as a potential complementary and alternative therapeutic agent for the treatment of trigeminal nociceptive pain.

  17. Morinda citrifolia fruit juice prevents ischemic neuronal damage through suppression of the development of post-ischemic glucose intolerance.

    PubMed

    Harada, Shinichi; Fujita-Hamabe, Wakako; Kamiya, Kohei; Mizushina, Yoshiyuki; Satake, Toshiko; Tokuyama, Shogo

    2010-10-01

    Fruit juice of Morinda citrifolia (Noni juice) is a well-known health drink and has various pharmacological properties including antioxidant and anti-inflammatory effects. We have hitherto found the protective effect of Noni juice on brain damage caused by ischemic stress in mice. In addition, we also recently reported that regulation of post-ischemic glucose intolerance might be important for good prognosis. Here, we focused on the effect of Noni juice on the development of the post-ischemic glucose intolerance as a cerebral protective mechanism. Noni juice was obtained from the mature fruit grown in Okinawa (about 1.5 L/4 kg of fruit; 100% ONJ). Male ddY mice were given 10% ONJ in drinking water for 7 days. Then, mice were subjected to 2 h of middle cerebral artery occlusion (MCAO). Ingestion of 10% ONJ suppressed the development of neuronal damage after MCAO. Interestingly, glucose intolerance observed on the 1st day after MCAO completely disappeared after 10% ONJ administration. Furthermore, ONJ treatment significantly increased serum insulin levels much further than the control group on the 1st day, while serum adiponectin levels were not affected at all. These results suggest that ONJ could facilitate insulin secretion after ischemic stress and may attenuate the development of glucose intolerance. These mechanisms may contribute to the neuronal protective effect of ONJ against ischemic stress.

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-07-12

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

  20. Are mirror neurons the basis of speech perception? Evidence from five cases with damage to the purported human mirror system

    PubMed Central

    Rogalsky, Corianne; Love, Tracy; Driscoll, David; Anderson, Steven W.; Hickok, Gregory

    2013-01-01

    The discovery of mirror neurons in macaque has led to a resurrection of motor theories of speech perception. Although the majority of lesion and functional imaging studies have associated perception with the temporal lobes, it has also been proposed that the ‘human mirror system’, which prominently includes Broca’s area, is the neurophysiological substrate of speech perception. Although numerous studies have demonstrated a tight link between sensory and motor speech processes, few have directly assessed the critical prediction of mirror neuron theories of speech perception, namely that damage to the human mirror system should cause severe deficits in speech perception. The present study measured speech perception abilities of patients with lesions involving motor regions in the left posterior frontal lobe and/or inferior parietal lobule (i.e., the proposed human ‘mirror system’). Performance was at or near ceiling in patients with fronto-parietal lesions. It is only when the lesion encroaches on auditory regions in the temporal lobe that perceptual deficits are evident. This suggests that ‘mirror system’ damage does not disrupt speech perception, but rather that auditory systems are the primary substrate for speech perception. PMID:21207313

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed Central

    Maléth, József; Hegyi, Péter

    2016-01-01

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

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

    EPA Science Inventory

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

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

    PubMed

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

    2016-01-01

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

  5. Gastroprotective Effects of PMK-S005 against Ethanol-Induced Acute Gastric Damage in Rats

    PubMed Central

    Choi, Yoon Jeong; Kim, Nayoung; Lee, Ju Yup; Nam, Ryoung Hee; Seo, Ji Hyung; Lee, Seonmin; Kim, Hee Jin; Choi, Yoon Jin; Lee, Hye Seung; Lee, Dong Ho

    2016-01-01

    Background/Aims This study aimed to examine the gastroprotective effects of PMK-S005, which is a synthetic S-allyl-l-cysteine (SAC; a sulfur-containing amino acid), against acute ethanol-induced gastric damage in rats. Methods Sprague-Dawley rats were divided into six groups, including a nonethanol group, groups treated with absolute ethanol 1 hour after pretreatment with various doses of PMK-S005 (1, 5, and 10 mg/kg) or rebamipide (50 mg/kg), and an absolute ethanol-only group. Ethanol-induced gross ulcer and mucus levels were measured. Myeloperoxidase, tumor necrosis factor α, interleukin 1β, PGE2, LTB4, cPLA2, COX-1, and COX-2 levels were estimated by enzyme-linked immunosorbent assay or Western blot analysis. Furthermore, the protein expression levels of antioxidant enzymes, including heme oxygenase-1 (HO-1), NAD(P)H:quinine oxidoreductase 1 (NQO-1), GCLC, and GCLM, were assessed. Results PMK-S005 significantly attenuated the ethanol-induced gastric damage; it reduced mucosal inflammatory cytokine production and increased mucus levels. The expression levels of cPLA2, COX-1, and COX-2 were decreased by PMK-S005. PMK-S005 did not affect PGE2 synthesis, but LTB4 production was significantly suppressed. In addition, long-term administration of PMK-S005 significantly increased the expression of HO-1, NQO-1, GCLC, and GCLM. Conclusions These results strongly suggest that PMK-S005 prevents gastric mucosal damage and that these gastroprotective activities are due to anti-inflammatory effects and enhancement of the gastric defense system, including antioxidant enzymes. PMID:26347516

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

    PubMed

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

    2012-03-01

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

  7. PEP-1-GSTpi protein enhanced hippocampal neuronal cell survival after oxidative damage

    PubMed Central

    Sohn, Eun Jeong; Shin, Min Jea; Kim, Dae Won; Son, Ora; Jo, Hyo Sang; Cho, Su Bin; Park, Jung Hwan; Lee, Chi Hern; Yeo, Eun Ji; Choi, Yeon Joo; Yu, Yeon Hee; Kim, Duk-Soo; Cho, Sung-Woo; Kwon, Oh Shin; Cho, Yong-Jun; Park, Jinseu; Eum, Won Sik; Choi, Soo Young

    2016-01-01

    Reactive oxygen species generated under oxidative stress are involved in neuronal diseases, including ischemia. Glutathione S-transferase pi (GSTpi) is a member of the GST family and is known to play important roles in cell survival. We investigated the effect of GSTpi against oxidative stress-induced hippocampal HT-22 cell death, and its effects in an animal model of ischemic injury, using a cell-permeable PEP-1-GSTpi protein. PEP-1-GSTpi was transduced into HT-22 cells and significantly protected against H2O2-treated cell death by reducing the intracellular toxicity and regulating the signal pathways, including MAPK, Akt, Bax, and Bcl-2. PEP-1-GSTpi transduced into the hippocampus in animal brains, and markedly protected against neuronal cell death in an ischemic injury animal model. These results indicate that PEP-1-GSTpi acts as a regulator or an antioxidant to protect against oxidative stress-induced cell death. Our study suggests that PEP-1-GSTpi may have potential as a therapeutic agent for the treatment of ischemia and a variety of oxidative stress-related neuronal diseases. [BMB Reports 2016; 49(7): 382-387] PMID:27049109

  8. Suberoylanilide hydroxamic acid, a histone deacetylase inhibitor, protects dopaminergic neurons from neurotoxin-induced damage

    PubMed Central

    Chen, SH; Wu, HM; Ossola, B; Schendzielorz, N; Wilson, BC; Chu, CH; Chen, SL; Wang, Q; Zhang, D; Qian, L; Li, X; Hong, JS; Lu, RB

    2012-01-01

    BACKGROUND AND PURPOSE Prevention or disease-modifying therapies are critical for the treatment of neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease and Huntington's disease. However, no such intervention is currently available. Growing evidence has demonstrated that administration of histone deacetylase (HDAC) inhibitors ameliorates a wide range of neurologic and psychiatric disorders in experimental models. Suberoylanilide hydroxamic acid (SAHA) was the first HDAC inhibitor approved by the Food and Drug Administration for the sole use of cancer therapy. The purpose of this study was to explore the potential new indications of SAHA for therapy of neurodegenerative diseases in in vitro Parkinson's disease models. EXPERIMENTAL APPROACH Mesencephalic neuron–glia cultures and reconstituted cultures were used to investigate neurotrophic and neuroprotective effects of SAHA. We measured toxicity in dopaminergic neurons, using dopamine uptake assay and morphological analysis and expression of neurotrophic substances by enzyme-linked immunosorbent assay and real-time RT PCR. KEY RESULTS In mesencephalic neuron–glia cultures, SAHA displayed dose- and time-dependent prolongation of the survival and protection against neurotoxin-induced neuronal death of dopaminergic neurons. Mechanistic studies revealed that the neuroprotective effects of SAHA were mediated in part by promoting release of neurotrophic factors from astroglia through inhibition of histone deacetylation. CONCLUSION AND IMPLICATIONS The novel neurotrophic and neuroprotective effects of SAHA demonstrated in this study suggest that further study of this HDAC inhibitor could provide a new therapeutic approach to the treatment of neurodegenerative diseases. PMID:21726209

  9. 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

  10. The Neuroprotective Effects of Brazilian Green Propolis on Neurodegenerative Damage in Human Neuronal SH-SY5Y Cells.

    PubMed

    Ni, Junjun; Wu, Zhou; Meng, Jie; Zhu, Aiqin; Zhong, Xin; Wu, Shizheng; Nakanishi, Hiroshi

    2017-01-01

    Oxidative stress and synapse dysfunction are the major neurodegenerative damage correlated to cognitive impairment in Alzheimer's disease (AD). We have found that Brazilian green propolis (propolis) improves the cognitive functions of mild cognitive impairment patients living at high altitude; however, mechanism underlying the effects of propolis is unknown. In the present study, we investigated the effects of propolis on oxidative stress, expression of brain-derived neurotrophic factor (BDNF), and activity-regulated cytoskeleton-associated protein (Arc), the critical factors of synapse efficacy, using human neuroblastoma SH-SY5Y cells. Pretreatment with propolis significantly ameliorated the hydrogen peroxide- (H2O2-) induced cytotoxicity in SH-SY5Y cells. Furthermore, propolis significantly reduced the H2O2-generated reactive oxygen species (ROS) derived from mitochondria and 8-oxo-2'-deoxyguanosine (8-oxo-dG, the DNA oxidative damage marker) but significantly reversed the fibrillar β-amyloid and IL-1β-impaired BDNF-induced Arc expression in SH-SY5Y cells. Furthermore, propolis significantly upregulated BDNF mRNA expression in time- and dose-dependent manners. In addition, propolis induced Arc mRNA and protein expression via phosphoinositide-3 kinase (PI3K). These observations strongly suggest that propolis protects from the neurodegenerative damage in neurons through the properties of various antioxidants. The present study provides a potential molecular mechanism of Brazilian green propolis in prevention of cognitive impairment in AD as well as aging.

  11. The Neuroprotective Effects of Brazilian Green Propolis on Neurodegenerative Damage in Human Neuronal SH-SY5Y Cells

    PubMed Central

    Ni, Junjun; Meng, Jie; Zhu, Aiqin; Zhong, Xin; Wu, Shizheng; Nakanishi, Hiroshi

    2017-01-01

    Oxidative stress and synapse dysfunction are the major neurodegenerative damage correlated to cognitive impairment in Alzheimer's disease (AD). We have found that Brazilian green propolis (propolis) improves the cognitive functions of mild cognitive impairment patients living at high altitude; however, mechanism underlying the effects of propolis is unknown. In the present study, we investigated the effects of propolis on oxidative stress, expression of brain-derived neurotrophic factor (BDNF), and activity-regulated cytoskeleton-associated protein (Arc), the critical factors of synapse efficacy, using human neuroblastoma SH-SY5Y cells. Pretreatment with propolis significantly ameliorated the hydrogen peroxide- (H2O2-) induced cytotoxicity in SH-SY5Y cells. Furthermore, propolis significantly reduced the H2O2-generated reactive oxygen species (ROS) derived from mitochondria and 8-oxo-2′-deoxyguanosine (8-oxo-dG, the DNA oxidative damage marker) but significantly reversed the fibrillar β-amyloid and IL-1β-impaired BDNF-induced Arc expression in SH-SY5Y cells. Furthermore, propolis significantly upregulated BDNF mRNA expression in time- and dose-dependent manners. In addition, propolis induced Arc mRNA and protein expression via phosphoinositide-3 kinase (PI3K). These observations strongly suggest that propolis protects from the neurodegenerative damage in neurons through the properties of various antioxidants. The present study provides a potential molecular mechanism of Brazilian green propolis in prevention of cognitive impairment in AD as well as aging. PMID:28265338

  12. Contributions of Bcl-xL to acute and long term changes in bioenergetics during neuronal plasticity.

    PubMed

    Jonas, Elizabeth A

    2014-08-01

    Mitochondria manufacture and release metabolites and manage calcium during neuronal activity and synaptic transmission, but whether long term alterations in mitochondrial function contribute to the neuronal plasticity underlying changes in organism behavior patterns is still poorly understood. Although normal neuronal plasticity may determine learning, in contrast a persistent decline in synaptic strength or neuronal excitability may portend neurite retraction and eventual somatic death. Anti-death proteins such as Bcl-xL not only provide neuroprotection at the neuronal soma during cell death stimuli, but also appear to enhance neurotransmitter release and synaptic growth and development. It is proposed that Bcl-xL performs these functions through its ability to regulate mitochondrial release of bioenergetic metabolites and calcium, and through its ability to rapidly alter mitochondrial positioning and morphology. Bcl-xL also interacts with proteins that directly alter synaptic vesicle recycling. Bcl-xL translocates acutely to sub-cellular membranes during neuronal activity to achieve changes in synaptic efficacy. After stressful stimuli, pro-apoptotic cleaved delta N Bcl-xL (ΔN Bcl-xL) induces mitochondrial ion channel activity leading to synaptic depression and this is regulated by caspase activation. During physiological states of decreased synaptic stimulation, loss of mitochondrial Bcl-xL and low level caspase activation occur prior to the onset of long term decline in synaptic efficacy. The degree to which Bcl-xL changes mitochondrial membrane permeability may control the direction of change in synaptic strength. The small molecule Bcl-xL inhibitor ABT-737 has been useful in defining the role of Bcl-xL in synaptic processes. Bcl-xL is crucial to the normal health of neurons and synapses and its malfunction may contribute to neurodegenerative disease.

  13. Neuronal DNA damage response‐associated dysregulation of signalling pathways and cholesterol metabolism at the earliest stages of Alzheimer‐type pathology

    PubMed Central

    Simpson, Julie E.; Ince, Paul G.; Minett, Thais; Matthews, Fiona E.; Heath, Paul R.; Shaw, Pamela J.; Goodall, Emily; Garwood, Claire J.; Ratcliffe, Laura E.; Brayne, Carol; Rattray, Magnus

    2015-01-01

    Aims Oxidative damage and an associated DNA damage response (DDR) are evident in mild cognitive impairment and early Alzheimer's disease, suggesting that neuronal dysfunction resulting from oxidative DNA damage may account for some of the cognitive impairment not fully explained by Alzheimer‐type pathology. Methods Frontal cortex (Braak stage 0–II) was obtained from the Medical Research Council's Cognitive Function and Ageing Study cohort. Neurones were isolated from eight cases (four high and four low DDR) by laser capture microdissection and changes in the transcriptome identified by microarray analysis. Results Two thousand three hundred seventy‐eight genes were significantly differentially expressed (1690 up‐regulated, 688 down‐regulated, P < 0.001) in cases with a high neuronal DDR. Functional grouping identified dysregulation of cholesterol biosynthesis, insulin and Wnt signalling, and up‐regulation of glycogen synthase kinase 3β. Candidate genes were validated by quantitative real‐time polymerase chain reaction. Cerebrospinal fluid levels of 24(S)‐hydroxycholesterol associated with neuronal DDR across all Braak stages (r s = 0.30, P = 0.03). Conclusions A persistent neuronal DDR may result in increased cholesterol biosynthesis, impaired insulin and Wnt signalling, and increased GSK3β, thereby contributing to neuronal dysfunction independent of Alzheimer‐type pathology in the ageing brain. PMID:26095650

  14. Neuronal damage using fluoro-Jade B histofluorescence and gliosis in the gerbil septum submitted to various durations of cerebral ischemia.

    PubMed

    Park, Chan Woo; Lee, Jae-Chul; Ahn, Ji Hyeon; Lee, Dae Hwan; Cho, Geum-Sil; Yan, Bing Chun; Park, Joon Ha; Kim, In Hye; Lee, Hui Young; Won, Moo-Ho; Cho, Jun Hwi

    2013-10-01

    The extent of neuronal damage/death in some brain regions is highly correlated to duration time of transient ischemia. In the present study, we carried out neuronal degeneration/death and glial changes in the septum 4 days after 5, 10, 15, and 20 min of transient cerebral ischemia using gerbils. To examine neuronal damage, Fluoro-Jade B (F-J B, a marker for neuronal degeneration) histofluorescence staining was used. F-J B positive ((+)) cells were detected in the septo-hippocampal nucleus (SHN) of the septum only in the 20 min ischemia-group; the mean number of F-J B(+) neurons was 14.9 ± 2.5/400 μm(2) in a section. Gliosis of astrocytes and microglia was examined using anti-glial fibrillary acidic protein (GFAP) and anti-ionized calcium-binding adapter molecule 1 (Iba-1), respectively. In all the ischemia-groups, GFAP- and Iba-1-immunoreactive astrocytes and microglia, respectively, were increased in number, and apparently tended to be increased in their immunoreactivity. Especially, in the 20 min ischemia-group, the number and immunoreactivity of Iba-immunoreactive microglia was highest and strongest in the ischemic SHN 4 days after ischemia-reperfusion. In brief, our findings showed that neuronal damage/death in the SHN occurred and gliosis was apparently increased in the 20 min ischemia-group at 4 days after ischemia-reperfusion.

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

    PubMed

    Kirilly, Eszter

    2010-09-01

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

  16. Neonatal Tissue Damage Promotes Spike Timing-Dependent Synaptic Long-Term Potentiation in Adult Spinal Projection Neurons

    PubMed Central

    Li, Jie

    2016-01-01

    Mounting evidence from both humans and rodents suggests that tissue damage during the neonatal period can “prime” developing nociceptive pathways such that a subsequent injury during adulthood causes an exacerbated degree of pain hypersensitivity. However, the cellular and molecular mechanisms that underlie this priming effect remain poorly understood. Here, we demonstrate that neonatal surgical injury relaxes the timing rules governing long-term potentiation (LTP) at mouse primary afferent synapses onto mature lamina I projection neurons, which serve as a major output of the spinal nociceptive network and are essential for pain perception. In addition, whereas LTP in naive mice was only observed if the presynaptic input preceded postsynaptic firing, early tissue injury removed this temporal requirement and LTP was observed regardless of the order in which the inputs were activated. Neonatal tissue damage also reduced the dependence of spike-timing-dependent LTP on NMDAR activation and unmasked a novel contribution of Ca2+-permeable AMPARs. These results suggest for the first time that transient tissue damage during early life creates a more permissive environment for the production of LTP within adult spinal nociceptive circuits. This persistent metaplasticity may promote the excessive amplification of ascending nociceptive transmission to the mature brain and thereby facilitate the generation of chronic pain after injury, thus representing a novel potential mechanism by which early trauma can prime adult pain pathways in the CNS. SIGNIFICANCE STATEMENT Tissue damage during early life can “prime” developing nociceptive pathways in the CNS, leading to greater pain severity after repeat injury via mechanisms that remain poorly understood. Here, we demonstrate that neonatal surgical injury widens the timing window during which correlated presynaptic and postsynaptic activity can evoke long-term potentiation (LTP) at sensory synapses onto adult lamina I

  17. Repair of oxidative DNA damage, cell-cycle regulation and neuronal death may influence the clinical manifestation of Alzheimer's disease.

    PubMed

    Silva, Aderbal R T; Santos, Ana Cecília Feio; Farfel, Jose M; Grinberg, Lea T; Ferretti, Renata E L; Campos, Antonio Hugo Jose Froes Marques; Cunha, Isabela Werneck; Begnami, Maria Dirlei; Rocha, Rafael M; Carraro, Dirce M; de Bragança Pereira, Carlos Alberto; Jacob-Filho, Wilson; Brentani, Helena

    2014-01-01

    Alzheimer's disease (AD) is characterized by progressive cognitive decline associated with a featured neuropathology (neuritic plaques and neurofibrillary tangles). Several studies have implicated oxidative damage to DNA, DNA repair, and altered cell-cycle regulation in addition to cell death in AD post-mitotic neurons. However, there is a lack of studies that systematically assess those biological processes in patients with AD neuropathology but with no evidence of cognitive impairment. We evaluated markers of oxidative DNA damage (8-OHdG, H2AX), DNA repair (p53, BRCA1, PTEN), and cell-cycle (Cdk1, Cdk4, Cdk5, Cyclin B1, Cyclin D1, p27Kip1, phospho-Rb and E2F1) through immunohistochemistry and cell death through TUNEL in autopsy hippocampal tissue samples arrayed in a tissue microarray (TMA) composed of three groups: I) "clinical-pathological AD" (CP-AD)--subjects with neuropathological AD (Braak ≥ IV and CERAD = B or C) and clinical dementia (CDR ≥ 2, IQCODE>3.8); II) "pathological AD" (P-AD)--subjects with neuropathological AD (Braak ≥ IV and CERAD = B or C) and without cognitive impairment (CDR 0, IQCODE<3.2); and III) "normal aging" (N)--subjects without neuropathological AD (Braak ≤ II and CERAD 0 or A) and with normal cognitive function (CDR 0, IQCODE<3.2). Our results show that high levels of oxidative DNA damage are present in all groups. However, significant reductions in DNA repair and cell-cycle inhibition markers and increases in cell-cycle progression and cell death markers in subjects with CP-AD were detected when compared to both P-AD and N groups, whereas there were no significant differences in the studied markers between P-AD individuals and N subjects. This study indicates that, even in the setting of pathological AD, healthy cognition may be associated with a preserved repair to DNA damage, cell-cycle regulation, and cell death in post-mitotic neurons.

  18. 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

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

    PubMed

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

    2013-01-28

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

  20. 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.

  1. Juliprosopine and juliprosine from prosopis juliflora leaves induce mitochondrial damage and cytoplasmic vacuolation on cocultured glial cells and neurons.

    PubMed

    Silva, Victor Diogenes A; Pitanga, Bruno P S; Nascimento, Ravena P; Souza, Cleide S; Coelho, Paulo Lucas C; Menezes-Filho, Noélio; Silva, André Mário M; Costa, Maria de Fátima D; El-Bachá, Ramon S; Velozo, Eudes S; Costa, Silvia L

    2013-12-16

    Prosopis juliflora is a shrub largely used for animal and human consumption. However, ingestion has been shown to induce intoxication in animals, which is characterized by neuromuscular alterations induced by mechanisms that are not yet well understood. In this study, we investigated the cytotoxicity of a total alkaloid extract (TAE) and one alkaloid fraction (F32) obtained from P. juliflora leaves to rat cortical neurons and glial cells. Nuclear magnetic resonance characterization of F32 showed that this fraction is composed of a mixture of two piperidine alkaloids, juliprosopine (majority constituent) and juliprosine. TAE and F32 at concentrations between 0.3 and 45 μg/mL were tested for 24 h on neuron/glial cell primary cocultures. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test revealed that TAE and F32 were cytotoxic to cocultures, and their IC50 values were 31.07 and 7.362 μg/mL, respectively. Exposure to a subtoxic concentration of TAE or F32 (0.3-3 μg/mL) induced vacuolation and disruption of the astrocyte monolayer and neurite network, ultrastructural changes, characterized by formation of double-membrane vacuoles, and mitochondrial damage, associated with changes in β-tubulin III and glial fibrillary acidic protein expression. Microglial proliferation was also observed in cultures exposed to TAE or F32, with increasing levels of OX-42-positive cells. Considering that F32 was more cytotoxic than TAE and that F32 reproduced in vitro the main morphologic and ultrastructural changes of "cara torta" disease, we can also suggest that piperidine alkaloids juliprosopine and juliprosine are primarily responsible for the neurotoxic damage observed in animals after they have consumed the plant.

  2. Neuroprotective effects of α-iso-cubebene against glutamate-induced damage in the HT22 hippocampal neuronal cell line.

    PubMed

    Park, Sun Young; Jung, Won Jung; Kang, Jum Soon; Kim, Cheol-Min; Park, Geuntae; Choi, Young-Whan

    2015-02-01

    Since oxidative stress is critically involved in excitotoxic damage, we sought to determine whether the activation of the transcription factors, cAMP-responsive element binding protein (CREB) and nuclear factor (erythroid-derived 2)-like 2 (Nrf2, also known as NFE2L2), by α-iso-cubebene is involved in its protective effects against glutamate-induced neuronal cell death. Pre-treatment with α-iso-cubebene significantly attenuated glutamate-induced cytotoxicity in mouse hippocampus-derived neuronal cells. α-iso-cubebene also reduced the glutamate-induced generation of reactive oxygen species and calcium influx, thus preventing apoptotic cell death. α-iso-cubebene inhibited glutamate-induced mitochondrial membrane depolarization and, consequently, inhibited the release of the apoptosis-inducing factor from the mitochondria. Immunoblot anlaysis revealed that the phosphorylation of extracellular signal-regulated kinase (ERK) by glutamate was reduced in the presence of α-iso-cubebene. α-iso-cubebene activated protein kinase A (PKA), CREB and Nrf2, which mediate the expression of the antioxidant enzymes, heme oxygenase-1 (HO-1) and NAD(P)H dehydrogenase [quinone] 1 (NQO1), involved in neuroprotection. In addition, α-iso-cubebene induced the expression of antioxidant responsive element and CRE transcriptional activity, thus conferring neuroprotection against glutamate-induced oxidative injury. α-iso-cubebene also induced the expression of Nrf2-dependent genes encoding HO-1 and NQO1. Furthermore, the knockdown of CREB and Nrf2 by small interfering RNA attenuated the neuroprotective effects of α-iso-cubebene. Taken together, our results indicate that α-iso-cubebene protects HT22 cells from glutamate-induced oxidative damage through the activation of Nrf2/HO-1/NQO-1, as well as through the PKA and CREB signaling pathways.

  3. Blood brain barrier impairment is associated with cerebrospinal fluid markers of neuronal damage in HIV-positive patients.

    PubMed

    Calcagno, A; Atzori, C; Romito, A; Vai, D; Audagnotto, S; Stella, M L; Montrucchio, C; Imperiale, D; Di Perri, G; Bonora, S

    2016-02-01

    Blood brain barrier impairment occurs early in the course of infection by HIV and it may persist in a subset of patients despite effective antiretroviral treatment. We tested the hypothesis that HIV-positive patients with dysfunctional blood brain barrier may have altered biomarkers of neuronal damage. In adult HIV-positive highly active antiretroviral treatment (HAART)-treated patients (without central nervous system infections and undergoing lumbar punctures for clinical reasons) cerebrospinal fluid albumin to serum ratios (CSAR), total tau, phosphorylated tau, 1-42 beta amyloid, and neopterin were measured. In 101 adult patients, cerebrospinal fluid-to-serum albumin ratios were 4.8 (3.7-6.1) with 12 patients (11.9%) presenting age-defined impaired blood brain barrier. A significant correlation was observed between CSAR and total tau (p = 0.005), phosphorylated tau (p = 0.008), and 1-42 beta amyloid (p = 0.040). Patients with impaired blood brain barrier showed significantly higher total tau (201.6 vs. 87.3 pg/mL, p = 0.010), phosphorylated tau (35.3 vs. 32.1 ng/mL, p = 0.035), and 1-42 beta amyloid (1134 vs. 830 pg/mL, p = 0.045). Despite effective antiretroviral treatment, blood brain barrier impairment persists in some HIV-positive patients: it is associated with markers of neuronal damage and it was not associated with CSF neopterin concentrations.

  4. Neuronal damage biomarkers in the identification of patients at risk of long-term postoperative cognitive dysfunction after cardiac surgery.

    PubMed

    Kok, W F; Koerts, J; Tucha, O; Scheeren, T W L; Absalom, A R

    2017-03-01

    Biomarkers of neurological injury can potentially predict postoperative cognitive dysfunction. We aimed to identify whether classical neuronal damage-specific biomarkers, including brain fatty acid-binding protein, neuron-specific enolase and S100 calcium-binding protein β, as well as plasma-free haemoglobin concentration as a measure of haemolysis, could be used to predict the risk of long-term cognitive decline after coronary artery bypass grafting with or without cardiopulmonary bypass. We assessed cognitive function using the CogState brief computerised cognitive test battery at 3 months and at 15 months after surgery. Blood samples were obtained pre-operatively, after sternal closure, and at 6 h and 24 h postoperatively. We found signs of cognitive decline at 3 months in 15 of 57 patients (26%), and in 13 of 48 patients (27%) at 15 months. Brain fatty acid-binding protein was already significantly higher before surgery in patients with postoperative cognitive dysfunction at 15 months, with pre-operative plasma levels of 22.8 (8.3-33.0 [0-44.6]) pg.ml(-1) compared with 9.7 (3.9-17.3 [0-49.0]) pg.ml(-1) in patients without cognitive dysfunction. This biomarker remained significantly higher in patients with cognitive decline throughout the entire postoperative period. At 3 months after surgery, high levels of plasma-free haemoglobin at sternal closure were associated with a negative influence on cognitive performance, as were high baseline scores on neuropsychological tests, whereas a higher level of education proved to beneficially influence cognitive outcome. We found that postoperative cognitive dysfunction at 3 months was associated with cognitive decline at 15 months after surgery, and served as a valuable prognostic factor for declines in individual cognitive performance one year later. Classical neuronal injury-related biomarkers were of no clear prognostic value.

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

    NASA Astrophysics Data System (ADS)

    Franck, Christian; Estrada, Jonathan

    2015-11-01

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

  6. Obatoclax potentiates the cytotoxic effect of cytarabine on acute myeloid leukemia cells by enhancing DNA damage.

    PubMed

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

    2015-02-01

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

  7. Inhibition of Ras signalling reduces neutrophil infiltration and tissue damage in severe acute pancreatitis.

    PubMed

    Yu, Changhui; Merza, Mohammed; Luo, Lingtao; Thorlacius, Henrik

    2015-01-05

    Neutrophil recruitment is known to be a rate-limiting step in mediating tissue injury in severe acute pancreatitis (AP). However, the signalling mechanisms controlling inflammation and organ damage in AP remain elusive. Herein, we examined the role of Ras signalling in AP. Male C57BL/6 mice were treated with a Ras inhibitor (farnesylthiosalicylic acid, FTS) before infusion of taurocholate into the pancreatic duct. Pancreatic and lung tissues as well as blood were collected 24 h after pancreatitis induction. Pretreatment with FTS decreased serum amylase levels by 82% and significantly attenuated acinar cell necrosis, tissue haemorrhage and oedema formation in taurocholate-induced pancreatitis. Inhibition of Ras signalling reduced myeloperoxidase (MPO) levels in the inflamed pancreas by 42%. In addition, administration of FTS decreased pancreatic levels of CXC chemokines as well as circulating levels of interleukin-6 and high-mobility group box 1 in animals exposed to taurocholate. Moreover, treatment with FTS reduced taurocholate-induced MPO levels in the lung. Inhibition of Ras signalling had no effect on neutrophil expression of Mac-1 in mice with pancreatitis. Moreover, FTS had no direct impact on trypsin activation in isolated pancreatic acinar cells. These results indicate that Ras signalling controls CXC chemokine formation, neutrophil recruitment and tissue injury in severe AP. Thus, our findings highlight a new signalling mechanism regulating neutrophil recruitment in the pancreas and suggest that inhibition of Ras signalling might be a useful strategy to attenuate local and systemic inflammation in severe AP.

  8. Effect of intestinal microbiota alteration on hepatic damage in rats with acute rejection after liver transplantation.

    PubMed

    Xie, Yirui; Chen, Huazhong; Zhu, Biao; Qin, Nan; Chen, Yunbo; Li, Zhengfeng; Deng, Min; Jiang, Haiyin; Xu, Xiangfei; Yang, Jiezuan; Ruan, Bing; Li, Lanjuan

    2014-11-01

    The previous studies all focus on the effect of probiotics and antibiotics on infection after liver transplantation. Here, we focus on the effect of gut microbiota alteration caused by probiotics and antibiotics on hepatic damage after allograft liver transplantation. Brown-Norway rats received saline, probiotics, or antibiotics via daily gavage for 3 weeks. Orthotopic liver transplantation (OLT) was carried out after 1 week of gavage. Alteration of the intestinal microbiota, liver function and histopathology, serum and liver cytokines, and T cells in peripheral blood and Peyer's patch were evaluated. Distinct segregation of fecal bacterial diversity was observed in the probiotic group and antibiotic group when compared with the allograft group. As for diversity of intestinal mucosal microbiota and pathology of intestine at 2 weeks after OLT, antibiotics and probiotics had a significant effect on ileum and colon. The population of Lactobacillus and Bifidobacterium in the probiotic group was significantly greater than the antibiotic group and the allograft group. The liver injury was significantly reduced in the antibiotic group and the probiotic group compared with the allograft group. The CD4/CD8 and Treg cells in Peyer's patch were decreased in the antibiotic group. The intestinal Treg cell and serum and liver TGF-β were increased markedly while CD4/CD8 ratio was significantly decreased in the probiotic group. It suggested that probiotics mediate their beneficial effects through increase of Treg cells and TGF-β and deduction of CD4/CD8 in rats with acute rejection (AR) after OLT.

  9. 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.

  10. Cellular NAD depletion and decline of SIRT1 activity play critical roles in PARP-1-mediated acute epileptic neuronal death in vitro.

    PubMed

    Wang, Shengjun; Yang, Xue; Lin, Youting; Qiu, Xiaoxue; Li, Hui; Zhao, Xiuhe; Cao, Lili; Liu, Xuewu; Pang, Yuejiu; Wang, Xuping; Chi, Zhaofu

    2013-10-16

    Intense poly(ADP-ribose) polymerase-1 (PARP-1) activation was implicated as a major cause of caspase-independent cell death in the hippocampal neuronal culture (HNC) model of acute acquired epilepsy (AE). The molecular mechanisms are quite complicated. The linkage among neuronal death, cellular nicotinamide adenine dinucleotide (NAD) levels, apoptosis-inducing factor (AIF) translocation, SIRT1 expression and activity were investigated here. The results showed that PARP-1 over-activation caused by Mg²⁺-free stimuli led to cellular NAD depletion which could block AIF translocation from mitochondria to nucleus and attenuate neuronal death. Also, SIRT1 deacetylase activity was reduced by Mg²⁺-free treatment, accompanied by elevated ratio of neuronal death, which could be rescued by NAD repletion. These data demonstrated that cellular NAD depletion and decline of SIRT1 activity play critical roles in PARP-1-mediated epileptic neuronal death in the HNC model of acute AE.

  11. Chronic organic manganese administration in the rat does not damage dopaminergic nigrostriatal neurons.

    PubMed

    Yong, V W; Perry, T L; Godolphin, W J; Jones, K A; Clavier, R M; Ito, M; Foulks, J G

    1986-01-01

    In an attempt to produce an animal model of Parkinson's disease, we injected rats repeatedly with high doses of methylcyclopentadienyl manganese tricarbonyl (MMT), a compound which has been reported to lower striatal dopamine content in mice. Chronic MMT administration for up to 5 months, even though it produced a substantial elevation in brain manganese content during the period of exposure, did not destroy dopaminergic nigrostriatal neurons. This was assessed by measurements of tyrosine hydroxylase activity and contents of dopamine and its metabolites in the striatum, and by histological examination of the substantia nigra. Our results differ from those of others who administered manganese chloride in drinking water to rats. This discrepancy is unlikely to be a consequence of differences in duration of exposure or route of administration. It could be due to our having used an organic rather than an inorganic manganese compound, or to a species difference in vulnerability to organic manganese between rats and mice.

  12. Neuroprotection by Brazilian Green Propolis against In vitro and In vivo Ischemic Neuronal Damage

    PubMed Central

    2005-01-01

    We examined whether Brazilian green propolis, a widely used folk medicine, has a neuroprotective function in vitro and/or in vivo. In vitro, propolis significantly inhibited neurotoxicity induced in neuronally differentiated PC12 cell cultures by either 24 h hydrogen peroxide (H2O2) exposure or 48 h serum deprivation. Regarding the possible underlying mechanism, propolis protected against oxidative stress (lipid peroxidation) in mouse forebrain homogenates and scavenged free radicals [induced by diphenyl-p-picrylhydrazyl (DPPH). In mice in vivo, propolis [30 or 100 mg/kg; intraperitoneally administered four times (at 2 days, 1 day and 60 min before, and at 4 h after induction of focal cerebral ischemia by permanent middle cerebral artery occlusion)] reduced brain infarction at 24 h after the occlusion. Thus, a propolis-induced inhibition of oxidative stress may be partly responsible for its neuroprotective function against in vitro cell death and in vivo focal cerebral ischemia. PMID:15937561

  13. 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

  14. Brain temperature, body core temperature, and intracranial pressure in acute cerebral damage

    PubMed Central

    Rossi, S; Zanier, E; Mauri, I; Columbo, A; Stocchetti, N

    2001-01-01

    OBJECTIVES—To assess the frequency of hyperthermia in a population of acute neurosurgical patients; to assess the relation between brain temperature (ICT) and core temperature (Tc); to investigate the effect of changes in brain temperature on intracranial pressure (ICP).
METHODS—The study involved 20 patients (10 severe head injury, eight subarachnoid haemorrhage, two neoplasms) with median Glasgow coma score (GCS) 6. ICP and ICT were monitored by an intraventricular catheter coupled with a thermistor. Internal Tc was measured in the pulmonary artery by a Swan-Ganz catheter.
RESULTS—Mean ICT was 38.4 (SD 0.8) and mean Tc 38.1 (SD 0.8)°C; 73% of ICT and 57.5% of Tc measurements were ⩾38°C. The mean difference between ICT and Tc was 0.3 (SD 0.3)°C (range −0.7 to 2.3°C) (p=0. 0001). Only in 12% of patients was Tc higher than ICT. The main reason for the differences between ICT and Tc was body core temperature: the difference between ICT and Tc increased significantly with body core temperature and fell significantly when this was lowered. The mean gradient between ICT and Tc was 0.16 (SD 0.31)°C before febrile episodes (ICT being higher than Tc), and 0.41 (SD 0.38)°C at the febrile peak (p<0.05). When changes in temperature were considered, ICT had a profound influence on ICP. Increases in ICT were associated with a significant rise in ICP, from 14.9(SD 7.9) to 22 (SD 10.4) mm Hg (p<0.05). As the fever ebbed there was a significant decrease in ICP, from 17.5 (SD 8.62) to 16 (SD 7.76) mm Hg (p=0.02).
CONCLUSIONS—Fever is extremely frequent during acute cerebral damage and ICT is significantly higher than Tc. Moreover, Tc may underestimate ICT during the phases when temperature has the most impact on the intracranial system because of the close association between increases in ICT and ICP.

 PMID:11561026

  15. Planning for selective amygdalohippocampectomy involving less neuronal fiber damage based on brain connectivity using tractography

    PubMed Central

    Lee, Seung-Hak; Kim, Mansu; Park, Hyunjin

    2015-01-01

    Temporal lobe resection is an important treatment option for epilepsy that involves removal of potentially essential brain regions. Selective amygdalohippocampectomy is a widely performed temporal lobe surgery. We suggest starting the incision for selective amygdalohippocampectomy at the inferior temporal gyrus based on diffusion magnetic resonance imaging (MRI) tractography. Diffusion MRI data from 20 normal participants were obtained from Parkinson's Progression Markers Initiative (PPMI) database (www.ppmi-info.org). A tractography algorithm was applied to extract neuronal fiber information for the temporal lobe, hippocampus, and amygdala. Fiber information was analyzed in terms of the number of fibers and betweenness centrality. Distances between starting incisions and surgical target regions were also considered to explore the length of the surgical path. Middle temporal and superior temporal gyrus regions have higher connectivity values than the inferior temporal gyrus and thus are not good candidates for starting the incision. The distances between inferior temporal gyrus and surgical target regions were shorter than those between middle temporal gyrus and target regions. Thus, the inferior temporal gyrus is a good candidate for starting the incision. Starting the incision from the inferior temporal gyrus would spare the important (in terms of betweenness centrality values) middle region and shorten the distance to the target regions of the hippocampus and amygdala. PMID:26330834

  16. Imipramine enhances neuroprotective effect of PEP-1-Catalase against ischemic neuronal damage.

    PubMed

    Kim, Dae Won; Kim, Duk-Soo; Kim, Mi Jin; Kwon, Soon Won; Ahn, Eun Hee; Jeong, Hoon Jae; Sohn, Eun Jeong; Dutta, Suman; Lim, Soon Sung; Cho, Sung-Woo; Lee, Kil Soo; Park, Jinseu; Eum, Won Sik; Hwang, Hyun Sook; Choi, Soo Young

    2011-10-01

    The protein transduction domains have been reported to have potential to deliver the exogenous molecules, including proteins, to living cells. However, poor transduction of proteins limits therapeutic application. In this study, we examined whether imipramine could stimulate the transduction efficiency of PEP-1 fused proteins into astrocytes. PEP-1-catalase (PEP-1- CAT) was transduced into astrocytes in a time- and dose-dependent manner, reducing cellular toxicity induced by H(2)O(2). Additionally, the group of PEP-1-CAT (+) imipramine showed enhancement of transduction efficiency and therefore increased cellular viability than that of PEP-1-CAT alone. In the gerbil ischemia models, PEP-1-CAT displayed significant neuroprotection in the CA1 region of the hippocampus. Interestingly, PEP-1-CAT (+) imipramine prevented neuronal cell death and lipid peroxidation more markedly than PEP-1-CAT alone. Therefore, our results suggest that imipramine can be used as a drug to enhance the transduction of PEP-1 fusion proteins to cells or animals and their efficacies against various disorders.

  17. Zonisamide suppresses endoplasmic reticulum stress-induced neuronal cell damage in vitro and in vivo.

    PubMed

    Tsujii, Saori; Ishisaka, Mitsue; Shimazawa, Masamitsu; Hashizume, Takanori; Hara, Hideaki

    2015-01-05

    Zonisamide has been reported to have protective effects on epilepsy and Parkinson׳s disease and to work via various mechanisms of action, such as inhibition of monoamine oxidase-B and enhancement of tyrosine hydroxylase. Recently, it has been suggested that zonisamide itself shows neuroprotective actions. Therefore, in the present study we investigated the neuroprotective effects of zonisamide against endoplasmic reticulum (ER) stress. We used human neuroblastoma (SH-SY5Y) cells and investigated the protective effects of zonisamide against tunicamycin- and thapsigargin-induced neuronal cell death. In addition, we investigated the effect of zonisamide against 1-methyl-4-phenylpyridinium (MPP⁺)-induced cell death and the mechanism of protection against ER stress. In vivo, we investigated the effect of zonisamide (20 mg/kg, p.o.) in the 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP)-induced mouse model of Parkinson׳s disease. Zonisamide not only suppressed MPP⁺-induced cell death, but also inhibited ER stress-induced cell death and suppressed the expression of ER stress-related factors such as C/EBO homologous protein (CHOP) in vivo. Furthermore, zonisamide inhibited the activation of caspase-3 in vitro. These results suggest that zonisamide affected ER stress via caspase-3. We think that ER stress, particularly the mechanism via caspase-3, is involved in part of the neuroprotective effect of zonisamide against the experimental models of Parkinson׳s disease.

  18. Gaps Between Aims and Achievements in Therapeutic Modification of Neuronal Damage ("Neuroprotection").

    PubMed

    Wiendl, Heinz; Elger, Christian; Förstl, Hans; Hartung, Hans-Peter; Oertel, Wolfgang; Reichmann, Heinz; Schwab, Stefan

    2015-04-01

    The term "neuroprotection" is often misused, overused, or misunderstood. A reasonable definition of neuroprotection refers to the preservation of "neuronal structure and/or function." Although our knowledge about the cellular and molecular mechanisms of neurodegeneration has expanded, experimental systems and animal models that mimic the process or allow translation into clinical success remain limited. This editorial discusses reasons for this gap and strategies to close it. Experimental models can only mirror certain aspects of disease mechanisms in humans. Therefore, findings in these models need to be linked with patient data to improve real-life relevance. Successful neuroprotection depends on finding the right "window of opportunity" which varies from very short (stroke) to very long (Alzheimer's disease), necessitating the need to focus on strategies for very early disease recognition. This need challenges the strategies to be chosen, trial approaches and methodologies, and the allocation of resources. Additionally, outcome measures are often not well suited to assess neuroprotection. To this end, surrogate measures, including biomarkers, are useful endpoints to demonstrate evidence of target directed therapeutic utility. Finally, studies have shown that neuroprotection is not likely to succeed when targeting only one pathway. These obstacles have reduced the level of enthusiasm for neuroprotection in certain disease areas (e.g., stroke). Academia, industry, regulatory authorities, funding agencies and patient organizations have to cooperate to a greater extent in order to overcome these impediments and to encourage nonclassical concepts. These concepts will be interdisciplinary in order to achieve meaningful disease modification.

  19. Effects of neuron-specific estrogen receptor (ER) α and ERβ deletion on the acute estrogen negative feedback mechanism in adult female mice.

    PubMed

    Cheong, Rachel Y; Porteous, Robert; Chambon, Pierre; Abrahám, István; Herbison, Allan E

    2014-04-01

    The negative feedback mechanism through which 17β-estradiol (E2) acts to suppress the activity of the GnRH neurons remains unclear. Using inducible and cell-specific genetic mouse models, we examined the estrogen receptor (ER) isoforms expressed by neurons that mediate acute estrogen negative feedback. Adult female mutant mice in which ERα was deleted from all neurons in the neonatal period failed to exhibit estrous cycles or negative feedback. Adult mutant female mice with neonatal neuronal ERβ deletion exhibited normal estrous cycles, but a failure of E2 to suppress LH secretion was seen in ovariectomized mice. Mutant mice with a GnRH neuron-selective deletion of ERβ exhibited normal cycles and negative feedback, suggesting no critical role for ERβ in GnRH neurons in acute negative feedback. To examine the adult roles of neurons expressing ERα, an inducible tamoxifen-based Cre-LoxP approach was used to ablate ERα from neurons that express calmodulin kinase IIα in adults. This resulted in mice with no estrous cycles, a normal increase in LH after ovariectomy, but an inability of E2 to suppress LH secretion. Finally, acute administration of ERα- and ERβ-selective agonists to adult ovariectomized wild-type mice revealed that activation of ERα suppressed LH secretion, whereas ERβ agonists had no effect. This study highlights the differences in adult reproductive phenotypes that result from neonatal vs adult ablation of ERα in the brain. Together, these experiments expand previous global knockout studies by demonstrating that neurons expressing ERα are essential and probably sufficient for the acute estrogen negative feedback mechanism in female mice.

  20. Vitamin D deficiency contributes to vascular damage in sustained ischemic acute kidney injury.

    PubMed

    de Bragança, Ana C; Volpini, Rildo A; Mehrotra, Purvi; Andrade, Lúcia; Basile, David P

    2016-07-01

    Reductions in renal microvasculature density and increased lymphocyte activity may play critical roles in the progression of chronic kidney disease (CKD) following acute kidney injury (AKI) induced by ischemia/reperfusion injury (IRI). Vitamin D deficiency is associated with tubulointerstitial damage and fibrosis progression following IRI-AKI We evaluated the effect of vitamin D deficiency in sustained IRI-AKI, hypothesizing that such deficiency contributes to the early reduction in renal capillary density or alters the lymphocyte response to IRI Wistar rats were fed vitamin D-free or standard diets for 35 days. On day 28, rats were randomized into four groups: control, vitamin D deficient (VDD), bilateral IRI, and VDD+IRI Indices of renal injury and recovery were evaluated for up to 7 days following the surgical procedures. VDD rats showed reduced capillary density (by cablin staining), even in the absence of renal I/R. In comparison with VDD and IRI rats, VDD+IRI rats manifested a significant exacerbation of capillary rarefaction as well as higher urinary volume, kidney weight/body weight ratio, tissue injury scores, fibroblast-specific protein-1, and alpha-smooth muscle actin. VDD+IRI rats also had higher numbers of infiltrating activated CD4(+) and CD8(+) cells staining for interferon gamma and interleukin-17, with a significant elevation in the Th17/T-regulatory cell ratio. These data suggest that vitamin D deficiency impairs renal repair responses to I/R injury, exacerbates changes in renal capillary density, as well as promoting fibrosis and inflammation, which may contribute to the transition from AKI to CKD.

  1. Korean red ginseng ameliorates acute 3-nitropropionic acid-induced cochlear damage in mice.

    PubMed

    Tian, Chunjie; Kim, Young Ho; Kim, Young Chul; Park, Kyung Tae; Kim, Seung Won; Kim, Youn Ju; Lim, Hye Jin; Choung, Yun-Hoon

    2013-01-01

    3-Nitropropionic acid (3-NP), a mitochondrial toxin, has been reported to induce an acute cochlear damage. Korean red ginseng (KRG) is known to have protective effects from some types of hearing loss. This study aimed to observe the protective effect of KRG in an ototoxic animal model using 3-NP intratympanic injection. BALB/c mice were classified into 5 groups (n=15) and dose-dependent toxic effects after intratympanic injection with 3-NP (300-5000 mM) on the left ear were investigated to determine the appropriate toxicity level of 3-NP. For observation of the protective effects of KRG, 23 mice were grouped into 3-NP (500 mM, n=12) and KRG+3-NP groups (300 mg/kg KRG for 7 days before 500 mM 3-NP administration, n=11). Auditory brain response (ABR) and cochlear morphological evaluations were performed before and after drug administration. The ABR thresholds in the 800-5000 mM groups exceeded the maximum recording limit at 16 and 32 kHz 1 day after 3-NP administration. The ABR threshold in the 500 mM 3-NP+KRG group was significantly lower than that in the 500 mM 3-NP group from post 1 week to 1 month. The mean type II fibrocyte counts significantly differed between the control and 3-NP groups and between the 3-NP and 3-NP+KRG groups. Spiral ganglion cell degeneration in the 3-NP group was more severe than that in the 3-NP+KRG group. This animal model exhibited a dose-dependent hearing loss with histological changes. KRG administration ameliorated the deterioration of hearing by 3-NP.

  2. The acute toxicity of iron and copper: biomolecule oxidation and oxidative damage in rat liver.

    PubMed

    Boveris, Alberto; Musacco-Sebio, Rosario; Ferrarotti, Nidia; Saporito-Magriñá, Christian; Torti, Horacio; Massot, Francisco; Repetto, Marisa G

    2012-11-01

    The transition metals iron (Fe) and copper (Cu) are needed at low levels for normal health and at higher levels they become toxic for humans and animals. The acute liver toxicity of Fe and Cu was studied in Sprague Dawley male rats (200 g) that received ip 0-60 mg/kg FeCl(2) or 0-30 mg/kg CuSO(4). Dose and time-responses were determined for spontaneous in situ liver chemiluminescence, phospholipid lipoperoxidation, protein oxidation and lipid soluble antioxidants. The doses linearly defined the tissue content of both metals. Liver chemiluminescence increased 4 times and 2 times after Fe and Cu overloads, with half maximal responses at contents (C(50%)) of 110 μgFe/g and 42 μgCu/g liver, and with half maximal time responses (t(1/2)) of 4h for both metals. Phospholipid peroxidation increased 4 and 1.8 times with C(50%) of 118 μg Fe/g and 45 μg Cu/g and with t(1/2) of 7h and 8h. Protein oxidation increased 1.6 times for Fe with C(50%) at 113 μg Fe/g and 1.2 times for Cu with 50 μg Cu/g and t(1/2) of 4h and 5h respectively. The accumulation of Fe and Cu in liver enhanced the rate of free radical reactions and produced oxidative damage. A similar free radical-mediated process, through the formation HO(•) and RO(•) by a Fenton-like homolytic scission of H(2)O(2) and ROOH, seems to operate as the chemical mechanism for the liver toxicity of both metals.

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

    SciTech Connect

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

    2015-02-13

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

  4. Hippocampal neurons in organotypic slice culture are highly resistant to damage by endogenous and exogenous nitric oxide.

    PubMed

    Keynes, Robert G; Duport, Sophie; Garthwaite, John

    2004-03-01

    Nitric oxide (NO) has been proposed to mediate neurodegeneration arising from NMDA receptor activity, but the issue remains controversial. The hypothesis was re-examined using organotypic slice cultures of rat hippocampus, with steps being taken to avoid known artefacts. The NO-cGMP signalling pathway was well preserved in such cultures. Brief exposure to NMDA resulted in a concentration-dependent delayed neuronal death that could be nullified by administration of the NMDA antagonist MK801 (10 microm) given postexposure. Two inhibitors of NO synthesis failed to protect the slices, despite fully blocking NMDA-induced cGMP accumulation. By comparing NMDA-induced cGMP accumulation with that produced by an NO donor, toxic NMDA concentrations were estimated to produce only physiological NO concentrations (2 nm). In studies of the vulnerability of the slices to exogenous NO, it was found that continuous exposure to up to 4.5 microm NO failed to affect ATP levels (measured after 6 h) or cause damage during 24 h, whereas treatment with the respiratory inhibitors myxothiazol or cyanide caused ATP depletion and complete cell death within 24 h. An NO concentration of 10 microm was required for ATP depletion and cell death, presumably through respiratory inhibition. It is concluded that sustained activity of neuronal NO synthase in intact hippocampal tissue can generate only low nanomolar NO concentrations, which are unlikely to be toxic. At the same time, the tissue is remarkably resistant to exogenous NO at up to 1000-fold higher concentrations. Together, the results seriously question the proposed role of NO in NMDA receptor-mediated excitotoxicity.

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

    PubMed Central

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

    2015-01-01

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

  6. 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

  7. 5-HT1A receptor activation counteracted the effect of acute immobilization of noradrenergic neurons in the rat locus coeruleus.

    PubMed

    Rioja, José; Santín, Luis J; López-Barroso, Diana; Doña, Alicia; Ulzurrun, Eugenia; Aguirre, José A

    2007-01-22

    The aim of our study was to evaluate the effect of acute stress and the 5-HT(1A) receptor involvement in both, the hippocampus noradrenaline (NA) tissue levels and the c-Fos immunoreactivity (c-Fos-IR) in the catecholaminergic neurons of the locus coeruleus (LC). Double immunocytochemical staining of tyrosine hydroxilase (TH) and c-Fos protein combined with stereological techniques were used to study the specific cell activation in the LC neurons in five experimental groups (control group, immobilization (1h) group, 8-OH-DPAT group (8-OH-DPAT 0.3mg/kg, s.c.), DPAT+IMMO group (8-OH-DPAT 0.3mg/kg, s.c., 30' prior acute immobilization) and WAY+DPAT+IMMO group (WAY-100635 0.3mg/kg, s.c. and 8-OH-DPAT 0.3mg/kg, s.c., 45'and 30', respectively, before immobilization). The results showed that hippocampal NA tissue levels and c-Fos-IR in the TH positive neurons of the LC were significantly increased immediately and after 90', respectively, after the immobilization period. Pre-treatment with 8-OH-DPAT counteracted the effects induced by immobilization, but pre-treatment with WAY-100635 did not block the effects induced by 8-OH-DPAT. These results suggest that noradrenaline system is associated in a significant way with immobilization stress. The role of 5-HT(1A) receptor activation in this stress response is also discussed.

  8. Cardiac Arrest Alters Regional Ubiquitin Levels in Association with the Blood-Brain Barrier Breakdown and Neuronal Damages in the Porcine Brain.

    PubMed

    Sharma, Hari S; Patnaik, Ranjana; Sharma, Aruna; Lafuente, José Vicente; Miclescu, Adriana; Wiklund, Lars

    2015-10-01

    The possibility that ubiquitin expression is altered in cardiac arrest-associated neuropathology was examined in a porcine model using immunohistochemical and biochemical methods. Our observations show that cardiac arrest induces progressive increase in ubiquitin expression in the cortex and hippocampus in a selective and specific manner as compared to corresponding control brains using enzyme-linked immunoassay technique (enzyme-linked immunosorbent assay (ELISA)). Furthermore, immunohistochemical studies showed ubiquitin expression in the neurons exhibiting immunoreaction in the cytoplasm and karyoplasm of distorted or damaged cells. Separate Nissl and ubiquitin staining showed damaged and distorted neurons and in the same cortical region ubiquitin expression indicating that ubiquitin expression after cardiac arrest represents dying neurons. The finding that methylene blue treatment markedly induced neuroprotection following identical cardiac arrest and reduced ubiquitin expression strengthens this view. Taken together, our observations are the first to show that cardiac arrest enhanced ubiquitin expression in the brain that is related to the magnitude of neuronal injury and the finding that methylene blue reduced ubiquitin expression points to its role in cell damage, not reported earlier.

  9. Characteristics of multiple Ca(2+)-activated K+ channels in acutely dissociated chick ciliary-ganglion neurones.

    PubMed Central

    Dryer, S E; Dourado, M M; Wisgirda, M E

    1991-01-01

    1. Whole-cell and single-channel recordings were used to characterize Ca(2+)-activated K+ channels (IK(Ca)) in acutely dissociated chick-ganglion neurones. 2. Application of depolarizing voltage steps resulted in outward currents that could be separated according to their dependence on external Ca2+ and/or holding potential. IK(Ca) was the only outward current that could be evoked from holding potentials of -50 mV or less. IK(Ca) was eliminated by bath application of Ca(2+)-free salines. A voltage-dependent outward current (IK(V)) could be evoked from more negative holding potentials in Ca(2+)-free salines. IK(V) was only partially blocked by as much as 30 mM-tetraethylammonium (TEA). 3. Tail currents associated with IK(Ca) reversed close to the K+ equilibrium potential (EK). IK(Ca) tail currents appeared sigmoidal, but the falling phase of the tail currents could be fitted with exponential curves that decayed faster at more negative membrane potentials. 4. IK(Ca) was blocked completely and reversibly by 10 mM-TEA. IK(Ca) was substantially reduced (80-90%) by as little as 1 mM-TEA. 5. Total IK(Ca) was reduced but not eliminated by saturating concentrations of apamin (200 nM). This blockade was not reversible with up to 30 min of washing. Application of 100 microM-d-tubocurare (dTC) also produced a partial blockade of total IK(Ca). 6. Whole-cell current-clamp recordings showed that IK(Ca) contributed to the late phases of spike repolarization and was the dominant current flowing during the spike after-hyperpolarization (AHP). Application of 200 nM-apamin caused a reduction in the duration of the AHP. This reduction was best seen when multiple spikes were evoked by prolonged (20-50 ms) injections of depolarizing current. 7. Three distinct types of IK(Ca) channels could be observed in inside-out patches in the presence of free Ca2+ concentrations of 2 x 10(-7) M, but not in the presence of free Ca2+ at concentrations of less than 10(-9) M. These had unitary chord

  10. Damage of GABAergic neurons in the medial septum impairs spatial working memory and extinction of active avoidance: effects on proactive interference.

    PubMed

    Pang, Kevin C H; Jiao, Xilu; Sinha, Swamini; Beck, Kevin D; Servatius, Richard J

    2011-08-01

    The medial septum and diagonal band (MSDB) are important in spatial learning and memory. On the basis of the excitotoxic damage of GABAergic MSDB neurons, we have recently suggested a role for these neurons in controlling proactive interference. Our study sought to test this hypothesis in different behavioral procedures using a new GABAergic immunotoxin. GABA-transporter-saporin (GAT1-SAP) was administered into the MSDB of male Sprague-Dawley rats. Following surgery, rats were trained in a reference memory water maze procedure for 5 days, followed by a working memory (delayed match to position) water maze procedure. Other rats were trained in a lever-press avoidance procedure after intraseptal GAT1-SAP or sham surgery. Intraseptal GAT1-SAP extensively damaged GABAergic neurons while sparing most cholinergic MSDB neurons. Rats treated with GAT1-SAP were not impaired in acquiring a spatial reference memory, learning the location of the escape platform as rapidly as sham rats. In contrast, GAT1-SAP rats were slower than sham rats to learn the platform location in a delayed match to position procedure, in which the platform location was changed every day. Moreover, GAT1-SAP rats returned to previous platform locations more often than sham rats. In the active avoidance procedure, intraseptal GAT1-SAP impaired extinction but not acquisition of the avoidance response. Using a different neurotoxin and behavioral procedures than previous studies, the results of this study paint a similar picture that GABAergic MSDB neurons are important for controlling proactive interference.

  11. Chemically induced neuronal damage and gliosis: enhanced expression of the proinflammatory chemokine, monocyte chemoattractant protein (MCP)-1, without a corresponding increase in proinflammatory cytokines(1).

    PubMed

    Little, A R; Benkovic, S A; Miller, D B; O'Callaghan, J P

    2002-01-01

    Enhanced expression of proinflammatory cytokines and chemokines has long been linked to neuronal and glial responses to brain injury. Indeed, inflammation in the brain has been associated with damage that stems from conditions as diverse as infection, multiple sclerosis, trauma, and excitotoxicity. In many of these brain injuries, disruption of the blood-brain barrier (BBB) may allow entry of blood-borne factors that contribute to, or serve as the basis of, brain inflammatory responses. Administration of trimethyltin (TMT) to the rat results in loss of hippocampal neurons and an ensuing gliosis without BBB compromise. We used the TMT damage model to discover the proinflammatory cytokines and chemokines that are expressed in response to neuronal injury. TMT caused pyramidal cell damage within 3 days and a substantial loss of these neurons by 21 days post dosing. Marked microglial activation and astrogliosis were evident over the same time period. The BBB remained intact despite the presence of multiple indicators of TMT-induced neuropathology. TMT caused large increases in whole hippocampal-derived monocyte chemoattractant protein (MCP)-1 mRNA (1,000%) by day 3 and in MCP-1 (300%) by day 7. The mRNA levels for tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta and IL-6, cytokines normally expressed during the earliest stage of inflammation, were not increased up to 21 days post dosing. Lipopolysaccharide, used as a positive control, caused large inductions of cytokine mRNA in liver, as well as an increase in IL-1beta in hippocampus, but it did not result in the induction of astrogliosis. The data suggest that enhanced expression of the proinflammatory cytokines, TNF-alpha, IL-1beta and IL-6, is not required for neuronal and glial responses to injury and that MCP-1 may serve a signaling function in the damaged CNS that is distinct from its role in proinflammatory events.

  12. Mutant SOD1 microglia-generated nitroxidative stress promotes toxicity to human fetal neural stem cell-derived motor neurons through direct damage and noxious interactions with astrocytes

    PubMed Central

    Thonhoff, Jason R; Gao, Junling; Dunn, Tiffany J; Ojeda, Luis; Wu, Ping

    2012-01-01

    Amyotrophic lateral sclerosis (ALS) is a devastating motor neuron disease. Human neural stem cells (hNSCs) may have the potential to replace lost motor neurons. The therapeutic efficacy of stem cell therapy depends greatly on the survival of grafted stem cell-derived motor neurons in the microenvironment of the spinal cord in ALS. After transplantation of hNSCs into the spinal cords of transgenic ALS rats, morphological analysis reveals that grafted hNSCs differentiate into motor neurons. However, hNSCs degenerate and show signs of nitroxidative damage at the disease end-stage. Using an in vitro coculture system, we systematically assess interactions between microglia and astroglia derived from both nontransgenic rats and transgenic rats expressing human mutant SOD1G93A before and after symptomatic disease onset, and determine the effects of such microglia-astroglia interactions on the survival of hNSC-derived motor neurons. We found that ALS microglia, specifically isolated after symptomatic disease onset, are directly toxic to hNSC-derived motor neurons. Furthermore, nontransgenic astrocytes not only lose their protective role in hNSC-derived motor neuron survival in vitro, but also exhibit toxic features when cocultured with mutant SOD1G93A microglia. Using inhibitors of inducible nitric oxide synthase and NADPH oxidase, we show that microglia-generated nitric oxide and superoxide partially contribute to motor neuron loss and astrocyte dysfunction in this coculture paradigm. In summary, reactive oxygen/nitrogen species released from overactivated microglia in ALS directly eliminate human neural stem cell-derived motor neurons and reduce the neuroprotective capacities of astrocytes PMID:23671793

  13. 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.

  14. Suppression of the DNA damage response in acute myeloid leukemia versus myelodysplastic syndrome.

    PubMed

    Boehrer, S; Adès, L; Tajeddine, N; Hofmann, W K; Kriener, S; Bug, G; Ottmann, O G; Ruthardt, M; Galluzzi, L; Fouassier, C; Tailler, M; Olaussen, K A; Gardin, C; Eclache, V; de Botton, S; Thepot, S; Fenaux, P; Kroemer, G

    2009-06-04

    The molecular mechanisms responsible for the evolution from the preleukemic entities of low-risk myelodysplastic syndrome (MDS) to the less favorable forms of high-risk MDS, as well as those enabling transformation to acute myeloid leukemia (AML), are still incompletely understood. Abundant evidence from solid tumors demonstrates that preneoplastic lesions activate signaling pathways of a DNA damage response (DDR), which functions as an 'anticancer barrier' hindering tumorigenesis. Testing the hypothesis that subgroups of MDS and AML differ with respect to DDR, we first assessed markers of DDR (phosphorylation of ATM, Chk-1, Chk-2 and H2AX) in cell lines representing different entities of MDS (P39, MOLM-13) and AML (MV4-11, KG-1) before and after gamma-irradiation. Although gamma-irradiation induced apoptosis and G(2)/M arrest and a concomitant increase in the phosphorylation of ATM, Chk-1 and H2AX in MDS-derived cell lines, this radiation response was attenuated in the AML-derived cell lines. It is noteworthy that KG-1, but not P39 cells exhibit signs of an endogenous activation of the DDR. Similarly, we found that the frequency of P-ATM(+) cells detectable in bone marrow (BM) biopsies increased in samples from patients with AML as compared with high-risk MDS samples and significantly correlated with the percentage of BM blasts. In contrast, the frequency of gamma-H2AX(+) cells was heterogeneous in all subgroups of AML and MDS. Whereas intermediate-1 MDS samples contained as little P-Chk-1 and P-Chk-2 as healthy controls, staining for both checkpoint kinases increased in intermediate-2 and high-risk MDS, yet declined to near-to-background levels in AML samples. Thus the activation of Chk-1 and Chk-2 behaves in accord with the paradigm established for solid tumors, whereas ATM is activated during and beyond transformation. In conclusion, we demonstrate the heterogeneity of the DDR response in MDS and AML and provide evidence for its selective suppression in AML

  15. Prolonged high fat diet ingestion, obesity, and type 2 diabetes symptoms correlate with phenotypic plasticity in myenteric neurons and nerve damage in the mouse duodenum.

    PubMed

    Stenkamp-Strahm, Chloe M; Nyavor, Yvonne E A; Kappmeyer, Adam J; Horton, Sarah; Gericke, Martin; Balemba, Onesmo B

    2015-08-01

    Symptoms of diabetic gastrointestinal dysmotility indicate neuropathy of the enteric nervous system. Long-standing diabetic enteric neuropathy has not been fully characterized, however. We used prolonged high fat diet ingestion (20 weeks) in a mouse model to mimic human obese and type 2 diabetic conditions, and analyzed changes seen in neurons of the duodenal myenteric plexus. Ganglionic and neuronal size, number of neurons per ganglionic area, density indices of neuronal phenotypes (immunoreactive nerve cell bodies and varicosities per ganglion or tissue area) and nerve injury were measured. Findings were compared with results previously seen in mice fed the same diet for 8 weeks. Compared to mice fed standard chow, those on a prolonged high fat diet had smaller ganglionic and cell soma areas. Myenteric VIP- and ChAT-immunoreactive density indices were also reduced. Myenteric nerve fibers were markedly swollen and cytoskeletal protein networks were disrupted. The number of nNOS nerve cell bodies per ganglia was increased, contrary to the reduction previously seen after 8 weeks, but the density index of nNOS varicosities was reduced. Mice fed high fat and standard chow diets experienced an age-related reduction in total neurons, with bias towards neurons of sensory phenotype. Meanwhile, ageing was associated with an increase in excitatory neuronal markers. Collectively, these results support a notion that nerve damage underlies diabetic symptoms of dysmotility, and reveals adaptive ENS responses to the prolonged ingestion of a high fat diet. This highlights a need to mechanistically study long-term diet-induced nerve damage and age-related impacts on the ENS.

  16. Antioxidant and hepatoprotective effects of Schisandra chinensis pollen extract on CCl4-induced acute liver damage in mice.

    PubMed

    Cheng, Ni; Ren, Naiyan; Gao, Hui; Lei, Xingsheng; Zheng, Jianbin; Cao, Wei

    2013-05-01

    The aim of the present study was to investigate the antioxidant and hepatotective effects of Schisandra chinensis pollen extract (SCPE) on CCl4-induced acute liver damage in mice. Total phenolic content, total flavonoid content, individual phenolic compounds and antioxidant activities (1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, chelating activity, and reducing power assay) were determined. In vivo study, SCPE (10, 20 and 40g/kg) administered daily orally for 42days prior to CCl4-intoxicated. Our results showed that SCPE had high total phenolic content (53.74±1.21mg GAE/g), total flavonoid content (38.29±0.91mg Rutin/g), quercetin and hesperetin may be the major contributor to strong antioxidant activities. Moreover, SCPE significantly prevented the increase in serum ALT and AST level in acute liver damage induced by CCl4, decreased the extent of malondialdehyde (MDA) formation in liver and elevated the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in liver. The results indicated that SCPE has strong antioxidant activities and significant protective effect against acute hepatotoxicity induced by CCl4, and have been supported by the evaluation of liver histopathology in mice. The hepatoprotective effect may be related to its free radical scavenging effect, increasing antioxidant activity and inhibiting lipid peroxidation.

  17. Effect of sesame oil against acetaminophen-induced acute oxidative hepatic damage in rats.

    PubMed

    Chandrasekaran, Victor Raj Mohan; Wan, Chang-Hsin; Liu, Li-Lian; Hsu, Dur-Zong; Liu, Ming-Yie

    2008-08-01

    Acetaminophen (APAP) overdose causes acute liver injury or even death in both humans and experimental animals. We investigated the effect of sesame oil on APAP-induced acute liver injury. Male Wistar rats were given APAP (1,000 mg/kg; orally) to induce acute liver injury. Acetaminophen significantly increased aspartate transaminase, alanine transaminase, lipid peroxidation, and superoxide anion and hydroxyl radical generation levels; it also induced glutathione depletion. Sesame oil (8 mL/kg; orally) did not alter the gastric absorption of APAP, but it inhibited all the parameters altered by APAP and protected the rats against APAP-induced acute liver injury. We hypothesize that sesame oil maintained the intracellular glutathione levels, reduced reactive oxygen species levels, and inhibited lipid peroxidation in rats with APAP-induced acute liver injury.

  18. Cerium Oxide Nanoparticles in Lung Acutely Induce Oxidative Stress, Inflammation, and DNA Damage in Various Organs of Mice

    PubMed Central

    Yuvaraju, Priya; Beegam, Sumaya; Fahim, Mohamed A.; Ali, Badreldin H.

    2017-01-01

    CeO2 nanoparticles (CeO2 NPs) which are used as a diesel fuel additive are emitted in the particulate phase in the exhaust, posing a health concern. However, limited information exists regarding the in vivo acute toxicity of CeO2 NPs on multiple organs. Presently, we investigated the acute (24 h) effects of intratracheally instilled CeO2 NPs in mice (0.5 mg/kg) on oxidative stress, inflammation, and DNA damage in major organs including lung, heart, liver, kidneys, spleen, and brain. Lipid peroxidation measured by malondialdehyde production was increased in the lungs only, and reactive oxygen species were increased in the lung, heart, kidney, and brain. Superoxide dismutase activity was decreased in the lung, liver, and kidney, whereas glutathione increased in lung but it decreased in the kidney. Total nitric oxide was increased in the lung and spleen but it decreased in the heart. Tumour necrosis factor-α increased in all organs studied. Interleukin- (IL-) 6 increased in the lung, heart, liver, kidney, and spleen. IL-1β augmented in the lung, heart, kidney, and spleen. Moreover, CeO2 NPs induced DNA damage, assessed by COMET assay, in all organs studied. Collectively, these findings indicate that pulmonary exposure to CeO2 NPs causes oxidative stress, inflammation, and DNA damage in multiple organs. PMID:28392888

  19. Formation of a fibrin based gelatinous coat over repairing rat gastric epithelium after acute ethanol damage: interaction with adherent mucus.

    PubMed Central

    Sellers, L A; Allen, A; Bennett, M K

    1987-01-01

    A gelatinous coat, heterogeneous in appearance, was formed over damaged rat gastric mucosa recovering from acute ethanol injury. This coat, in places 1.6 mm thick (median thickness 680 microns), was 10 times thicker than the translucent layer of adherent mucus (median thickness 70 microns) covering the undamaged mucosa. Immunohistochemistry and periodic acid Schiff staining showed this gelatinous coat to be predominantly a fibrin gel with an exterior layer rich in mucus and necrotic cells. The plasma clotting time was significantly decreased in vitro by pig gastric mucus gel and soluble mucus glycoprotein (90% and 13% respectively) suggesting that in vivo the mucus layer remaining after epithelial damage could act as a template for fibrinogen-fibrin conversion. These results show that a fibrin based gelatinous coat, quite distinct from the adherent mucus layer and with considerable protective potential could be formed over the repairing rat gastric mucosa after acute ethanol damage. Images Fig. 1 Fig. 2 Fig. 4 Fig. 5 Fig. 6 Fig. 7 PMID:3653751

  20. Fingolimod Limits Acute Aβ Neurotoxicity and Promotes Synaptic Versus Extrasynaptic NMDA Receptor Functionality in Hippocampal Neurons

    PubMed Central

    Joshi, Pooja; Gabrielli, Martina; Ponzoni, Luisa; Pelucchi, Silvia; Stravalaci, Matteo; Beeg, Marten; Mazzitelli, Sonia; Braida, Daniela; Sala, Mariaelvina; Boda, Enrica; Buffo, Annalisa; Gobbi, Marco; Gardoni, Fabrizio; Matteoli, Michela; Marcello, Elena; Verderio, Claudia

    2017-01-01

    Fingolimod, also known as FTY720, is an analogue of the sphingolipid sphingosine, which has been proved to be neuroprotective in rodent models of Alzheimer’s disease (AD). Several cellular and molecular targets underlying the neuroprotective effects of FTY720 have been recently identified. However, whether the drug directly protects neurons from toxicity of amyloid-beta (Aβ) still remains poorly defined. Using a combination of biochemical assays, live imaging and electrophysiology we demonstrate that FTY720 induces a rapid increase in GLUN2A-containing neuroprotective NMDARs on the surface of dendritic spines in cultured hippocampal neurons. In addition, the drug mobilizes extrasynaptic GLUN2B-containing NMDARs, which are coupled to cell death, to the synapses. Altered ratio of synaptic/extrasynaptic NMDARs decreases calcium responsiveness of neurons to neurotoxic soluble Aβ 1–42 and renders neurons resistant to early alteration of calcium homeostasis. The fast defensive response of FTY720 occurs through a Sphingosine-1-phosphate receptor (S1P-R) -dependent mechanism, as it is lost in the presence of S1P-R1 and S1P-R3 antagonists. We propose that rapid synaptic relocation of NMDARs might have direct impact on amelioration of cognitive performance in transgenic APPswe/PS1dE9 AD mice upon sub-chronic treatment with FTY720. PMID:28134307

  1. Association of epithelial damage and signs of neutrophil mobilization in the airways during acute exacerbations of paediatric asthma

    PubMed Central

    Yoshihara, S; Yamada, Y; Abe, T; Lindén, A; Arisaka, O

    2006-01-01

    We examined whether epithelial damage is associated with mobilization of neutrophils or eosinophils in the airway lumen during acute exacerbations of paediatric asthma. Aspirated sputum samples were harvested from 65 paediatric patients (mean age 3·4 ± 0·4 years) during acute exacerbations of asthma. Patients with signs of infection were excluded. The presence of conglomerates of epithelial cells (i.e. ‘Creola bodies) in the aspirated sputum was utilized as a marker of epithelial damage. Among the paediatric asthma patients, 60% displayed Creola bodies (CrB+: n = 39) in their sputum samples whereas the remaining patients did not (CrB–: n = 26). CrB+ patients displayed more than a 20-fold increase in the concentration of the neutrophil-mobilizing cytokine interleukin (IL)-8 (pg/ml) and of the neutrophil product neutrophil elastase (NE, g/l), respectively, compared with CrB– patients (IL-8: 7468·2 ± 1953·6 versus 347·9 ± 72·6, P < 0·01; NE: 2072·4 ± 419·0 versus 438·5 ± 125·7, P < 0·01). Even though not statistically significant, a corresponding trend was observed for the relative number of sputum neutrophils. In contrast, the concentration of the eosinophil-mobilizing cytokine IL-5 and the esoinophil product ECP tended to be lower in CrB+ than in CrB– patients (P > 0·05). In conclusion, as indicated by the analysis of aspirated sputum, epithelial damage is associated with a locally enhanced chemotactic signal for and activity of neutrophils, but not eosinophils, during acute exacerbations of paediatric asthma. It remains to be determined whether these indirect signs of neutrophil mobilization in the airway lumen mirror an increased number of neutrophils in the surrounding airway tissue. PMID:16634793

  2. Triphasic multinutrient supplementation during acute resistance exercise improves session volume load and reduces muscle damage in strength-trained athletes.

    PubMed

    Bird, Stephen P; Mabon, Tom; Pryde, Mitchell; Feebrey, Sarah; Cannon, Jack

    2013-05-01

    We hypothesized that triphasic multinutrient supplementation during acute resistance exercise would enhance muscular performance, produce a more favorable anabolic profile, and reduce biochemical markers of muscle damage in strength-trained athletes. Fifteen male strength-trained athletes completed two acute lower-body resistance exercise sessions to fatigue 7 days apart. After a 4-hour fast, participants consumed either a multinutrient supplement (Musashi 1-2-3 Step System, Notting Hill, Australia) (SUPP) or placebo (PLA) beverage preexercise (PRE), during (DUR), and immediately postexercise (IP). Session volume loads were calculated as kilograms × repetitions. Lower-body peak power was measured using unloaded repeated countermovement jumps, and blood samples were collected to assess biochemistry, serum hormones, and muscle damage markers at PRE, DUR, IP, 30 minutes postexercise (P30), and 24 hours postexercise (P24h). The SUPP demonstrated increased glucose concentrations at DUR and IP compared with at PRE (P < .01), whereas PLA demonstrated higher glucose at P30 compared with at PRE (P < .001). Session volume load was higher for SUPP compared with PLA (P < .05). Cortisol increased at DUR, IP, and P30 compared with at PRE in both treatments (P < .05); however, SUPP also displayed lower cortisol at P24h compared with at PRE and PLA (P < .01). The total testosterone response to exercise was higher for PLA compared with SUPP (P < .01); however, total creatine kinase and C-reactive protein responses to exercise were lower for SUPP compared with PLA (P < .05). These data indicate that although triphasic multinutrient supplementation did not produce a more favorable anabolic profile, it improved acute resistance exercise performance while attenuating muscle damage in strength-trained athletes.

  3. Acute Cocaine Induces Fast Activation of D1R and Progressive Deactivation of D2R Striatal Neurons: In vivo Optical MicroProbe [Ca2+]i Imaging

    PubMed Central

    Luo, Zhongchi; Volkow, Nora D.; Heintz, Nathaniel; Pan, Yingtian; Du, Congwu

    2011-01-01

    Cocaine induces fast dopamine increases in brain striatal regions, which are recognized to underlie its rewarding effects. Both dopamine D1 and D2 receptors are involved in cocaine’s reward but the dynamic downstream consequences of cocaine effects in striatum are not fully understood. Here we used transgenic mice expressing EGFP under the control of either the D1 receptor (D1R) or the D2 receptor (D2R) gene and microprobe optical imaging to assess the dynamic changes in intracellular calcium ([Ca2+]i) responses (used as marker of neuronal activation) to acute cocaine in vivo separately for D1R versus D2R expressing neurons in striatum. Acute cocaine (8 mg/kg ip) rapidly increased [Ca2+]i in D1R expressing neurons (10.6±3.2%) in striatum within 8.3±2.3min after cocaine administration after which the increases plateaued; these fast [Ca2+]i increases were blocked by pretreatment with a D1R antagonist (SCH 23390). In contrast cocaine induced progressive decreases in [Ca2+]i in D2R expressing neurons (10.4±5.8%) continuously throughout the 30min that followed cocaine administration; these slower [Ca2+]i decreases were blocked by pretreatment with a D2R antagonist (raclopride). Since activation of striatal D1R expressing neurons (direct-pathway) enhances cocaine reward whereas activation of D2R expressing neurons suppresses it (indirect-pathway) (Lobo et al., 2010), this suggests that cocaine’s rewarding effects entail both its fast stimulation of D1R (resulting in abrupt activation of direct-pathway neurons) and a slower stimulation of D2R (resulting in longer lasting deactivation of indirect-pathway neurons). We also provide direct in-vivo evidence of D2R and D1R interactions in the striatal responses to acute cocaine administration. PMID:21917801

  4. Impact of hyperthermia before and during ischemia-reperfusion on neuronal damage and gliosis in the gerbil hippocampus induced by transient cerebral ischemia.

    PubMed

    Kim, Min Joung; Cho, Jun Hwi; Cho, Jeong-Hwi; Park, Joon Ha; Ahn, Ji Hyeon; Tae, Hyun-Jin; Cho, Geum-Sil; Yan, Bing Chun; Hwang, In Koo; Lee, Choong Hyun; Bae, Eun Joo; Won, Moo-Ho; Lee, Jae-Chul

    2015-01-15

    Hyperthermia can exacerbate the brain damage produced by ischemia. In the present study, we investigated the effects of hyperthermia before and during ischemia-reperfusion on neuronal damage and glial changes in the gerbil hippocampus following transient cerebral ischemia using cresyl violet staining, NeuN immunohistochemistry and Fluoro-Jade B histofluorescence staining. The animals were randomly assigned to 4 groups: (1) sham-operated animals with normothermia (normothermia + sham group); (2) ischemia-operated animals with normothermia (normothermia + ischemia group); (3) sham-operated animals with hyperthermia (hyperthermia + sham group); and (4) ischemia-operated animals with hyperthermia (hyperthermia + ischemia group). Hyperthermia (39.5 ± 0.2°C) was induced by exposing the gerbils to a heating pad connected to a rectal thermistor for 30 min before and during ischemia-reperfusion. In the normothermia+ischemia groups, a significant delayed neuronal death was observed in the stratum pyramidale (SP) of the hippocampal CA1 region (CA1) 5 days after ischemia-reperfusion. In the hyperthermia+ischemia groups, neuronal death in the SP of the CA1 occurred at 1 day post-ischemia, and neuronal death was observed in the SP of the CA2/3 region at 2 days post-ischemia. In addition, we examined activations of astrocytes and microglia using immunohistochemistry for anti-glial fibrillary acidic protein (GFAP) and anti-ionized calcium-binding adapter molecule 1 (Iba-1). GFAP-positive astrocytes and Iba-1-positive microglia in the ischemic hippocampus were activated much earlier and much more accelerated in the hyperthermia+ischemia groups than those in the normothermia+ischemia groups. Based on our findings, we suggest that an experimentally hyperthermic pre-condition before cerebral ischemic insult produces more extensive neuronal damage and glial activation in the ischemic hippocampus.

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

    PubMed Central

    Akintunde, Jacob K.; Irechukwu, C. Abigail

    2016-01-01

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

  6. Focal neuronal damage in patients with neuropsychological impairment after diffuse traumatic brain injury: evaluation using ¹¹C-flumazenil positron emission tomography with statistical image analysis.

    PubMed

    Kawai, Nobuyuki; Maeda, Yukito; Kudomi, Nobuyuki; Yamamoto, Yuka; Nishiyama, Yoshihiro; Tamiya, Takashi

    2010-12-01

    This study was conducted to identify the regional neuronal damage occurring in patients with neuropsychological impairment following diffuse traumatic brain injury (TBI) compared with normal control subjects. In addition, measures of the neuropsychological tests were correlated with regional ¹¹C-flumazenil (FMZ) binding potential (BP) reductions to clarify the relationship between cognitive impairment and regional neuronal damage. We performed ¹¹C-flumazenil positron emission tomography (FMZ-PET) studies using three-dimensional stereotactic surface projection (3D-SSP) statistical image analysis in eight diffuse axonal injury (DAI) patients (mean age 29.1 ± 11.1 years, range 19-46 years). All patients underwent assessment with the Wechsler Adult Intellectual Scale-Third Edition (WAIS-III) to evaluate general intelligence. Twenty healthy control subjects (mean age 24.4 ± 2.8 years, range 22-30 years) were also studied to obtain a normal database for 3D-SSP. Group comparisons showed significant regional low FMZ uptake in the bilateral medial frontal gyri, the anterior cingulate gyri, and the thalamus. Individual analysis also showed decreased FMZ uptake in these regions; however, the distribution and extent of low FMZ uptake were different in each individual patient. Full-scale IQ (FIQ) and performance IQ (PIQ) negatively correlated with the degree of FMZ BP reduction (BZR index) in the right thalamus. FIQ, verbal IQ (VIQ), and PIQ also negatively correlated with the BZR index in the left medial frontal gyrus. DAI uniformly induced neuronal damage in the medial frontal cortex and the thalamus, which may be related to underlying cognitive impairments in diffuse TBI patients. Future studies to confirm a common area of focal neuronal damage and a direct correlation with neuropsychological testing may validate the use of FMZ-PET for the functional diagnosis of neuropsychological impairments after TBI.

  7. Systematic analysis of axonal damage and inflammatory response in different white matter tracts of acutely injured rat spinal cord.

    PubMed

    Gomes-Leal, W; Corkill, D J; Picanço-Diniz, C W

    2005-12-20

    The mechanisms of white matter (WM) damage during secondary degeneration are a fundamental issue in the pathophysiology of central nervous system (CNS) diseases. Our main goal was to describe the pattern of an acute inflammatory response and secondary damage to axons in different WM tracts of acutely injured rat spinal cord. Adult rats were deeply anesthetized and injected with 20 nmol of NMDA into the spinal cord ventral horn on T7. Animals were perfused after survival times of 1 day, 3 days and 7 days. Ten micrometer sections were submitted to immunocytochemical analysis for activated macrophages/microglia, neutrophils and damaged axons. There were inflammatory response and progressive tissue destruction of ventral WM (VWM) with formation of microcysts in both VWM and lateral WM (LWM). In the VWM, the number of beta-amyloid precursor protein (beta-APP) end-bulbs increased from 1 day with a peak at 3 days, decreasing by 7 days following the injection. APP end-bulbs were present in the dorsal WM (DWM) at 3 days survival time but were not in the LWM. Electron microscopic analysis revealed different degrees of myelin disruption and axonal pathology in the vacuolated WM up to 14 mm along the rostrocaudal axis. Quantitative analysis revealed a significant loss of medium and large axons (P < 0.05), but not of small axons (P > 0.05). Our results suggest that bystander axonal damage and myelin vacuolation are important secondary component of the pathology of WM tracts following rat SCI. Further studies are needed to understand the mechanisms of these pathological events.

  8. Disruption of IP₃R2-mediated Ca²⁺ signaling pathway in astrocytes ameliorates neuronal death and brain damage while reducing behavioral deficits after focal ischemic stroke.

    PubMed

    Li, Hailong; Xie, Yicheng; Zhang, Nannan; Yu, Yang; Zhang, Qiao; Ding, Shinghua

    2015-12-01

    Inositol trisphosphate receptor (IP3R)-mediated intracellular Ca(2+) increase is the major Ca(2+) signaling pathway in astrocytes in the central nervous system (CNS). Ca(2+) increases in astrocytes have been found to modulate neuronal function through gliotransmitter release. We previously demonstrated that astrocytes exhibit enhanced Ca(2+) signaling in vivo after photothrombosis (PT)-induced ischemia, which is largely due to the activation of G-protein coupled receptors (GPCRs). The aim of this study is to investigate the role of astrocytic IP3R-mediated Ca(2+) signaling in neuronal death, brain damage and behavior outcomes after PT. For this purpose, we conducted experiments using homozygous type 2 IP3R (IP3R2) knockout (KO) mice. Histological and immunostaining studies showed that IP3R2 KO mice were indeed deficient in IP3R2 in astrocytes and exhibited normal brain cytoarchitecture. IP3R2 KO mice also had the same densities of S100β+ astrocytes and NeuN+ neurons in the cortices, and exhibited the same glial fibrillary acidic protein (GFAP) and glial glutamate transporter (GLT-1) levels in the cortices and hippocampi as compared with wild type (WT) mice. Two-photon (2-P) imaging showed that IP3R2 KO mice did not exhibit ATP-induced Ca(2+) waves in vivo in the astrocytic network, which verified the disruption of IP3R-mediated Ca(2+) signaling in astrocytes of these mice. When subject to PT, IP3R2 KO mice had smaller infarction than WT mice in acute and chronic phases of ischemia. IP3R2 KO mice also exhibited less neuronal apoptosis, reactive astrogliosis, and tissue loss than WT mice. Behavioral tests, including cylinder, hanging wire, pole and adhesive tests, showed that IP3R2 KO mice exhibited reduced functional deficits after PT. Collectively, our study demonstrates that disruption of astrocytic Ca(2+) signaling by deleting IP3R2s has beneficial effects on neuronal and brain protection and functional deficits after stroke. These findings reveal a novel non

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

    PubMed Central

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

    2015-01-01

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

  10. P2Y1R-initiated, IP3R-dependent stimulation of astrocyte mitochondrial metabolism reduces and partially reverses ischemic neuronal damage in mouse

    PubMed Central

    Zheng, Wei; Talley Watts, Lora; Holstein, Deborah M; Wewer, Jimmy; Lechleiter, James D

    2013-01-01

    Glia-based neuroprotection strategies are emerging as promising new avenues to treat brain damage. We previously reported that activation of the glial-specific purinergic receptor, P2Y1R, reduces both astrocyte swelling and brain infarcts in a photothrombotic mouse model of stroke. These restorative effects were dependent on astrocyte mitochondrial metabolism. Here, we extend these findings and report that P2Y1R stimulation with the purinergic ligand 2-methylthioladenosine 5′ diphosphate (2MeSADP) reduces and partially reverses neuronal damage induced by photothrombosis. In vivo neuronal morphology was confocally imaged in transgenic mice expressing yellow fluorescent protein under the control of the Thy1 promoter. Astrocyte mitochondrial membrane potentials, monitored with the potential sensitive dye tetra-methyl rhodamine methyl ester, were depolarized after photothrombosis and subsequently repolarized when P2Y1Rs were stimulated. Mice deficient in the astrocyte-specific type 2 inositol 1,4,5 trisphosphate (IP3) receptor exhibited aggravated ischemic dendritic damage after photothrombosis. Treatment of these mice with 2MeSADP did not invoke an intracellular Ca2+ response, did not repolarize astrocyte mitochondria, and did not reduce or partially reverse neuronal lesions induced by photothrombotic stroke. These results demonstrate that IP3-Ca2+ signaling in astrocytes is not only critical for P2Y1R-enhanced protection, but suggest that IP3-Ca2+ signaling is also a key component of endogenous neuroprotection. PMID:23321785

  11. 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.

  12. Peptidylarginine deiminases: novel drug targets for prevention of neuronal damage following hypoxic ischemic insult (HI) in neonates.

    PubMed

    Lange, Sigrun; Rocha-Ferreira, Eridan; Thei, Laura; Mawjee, Priyanka; Bennett, Kate; Thompson, Paul R; Subramanian, Venkataraman; Nicholas, Anthony P; Peebles, Donald; Hristova, Mariya; Raivich, Gennadij

    2014-08-01

    Neonatal hypoxic ischaemic (HI) injury frequently causes neural impairment in surviving infants. Our knowledge of the underlying molecular mechanisms is still limited. Protein deimination is a post-translational modification caused by Ca(+2) -regulated peptidylarginine deiminases (PADs), a group of five isozymes that display tissue-specific expression and different preference for target proteins. Protein deimination results in altered protein conformation and function of target proteins, and is associated with neurodegenerative diseases, gene regulation and autoimmunity. In this study, we used the neonatal HI and HI/infection [lipopolysaccharide (LPS) stimulation] murine models to investigate changes in protein deimination. Brains showed increases in deiminated proteins, cell death, activated microglia and neuronal loss in affected brain areas at 48 h after hypoxic ischaemic insult. Upon treatment with the pan-PAD inhibitor Cl-amidine, a significant reduction was seen in microglial activation, cell death and infarct size compared with control saline or LPS-treated animals. Deimination of histone 3, a target protein of the PAD4 isozyme, was increased in hippocampus and cortex specifically upon LPS stimulation and markedly reduced following Cl-amidine treatment. Here, we demonstrate a novel role for PAD enzymes in neural impairment in neonatal HI Encephalopathy, highlighting their role as promising new candidates for drug-directed intervention in neurotrauma. Hypoxic Ischaemic Insult (HI) results in activation of peptidylarginine deiminases (PADs) because of calcium dysregulation. Target proteins undergo irreversible changes of protein bound arginine to citrulline, resulting in protein misfolding. Infection in synergy with HI causes up-regulation of TNFα, nuclear translocation of PAD4 and change in gene regulation as a result of histone deimination. Pharmacological PAD inhibition significantly reduced HI brain damage.

  13. Postsynaptic Receptors for Amyloid-β Oligomers as Mediators of Neuronal Damage in Alzheimer’s Disease

    PubMed Central

    Dinamarca, Margarita C.; Ríos, Juvenal A.; Inestrosa, Nibaldo C.

    2012-01-01

    The neurotoxic effect of amyloid-β peptide (Aβ) over the central synapses has been described and is reflected in the decrease of some postsynaptic excitatory proteins, the alteration in the number and morphology of the dendritic spines, and a decrease in long-term potentiation. Many studies has been carried out to identify the putative Aβ receptors in neurons, and is still no clear why the Aβ oligomers only affect the excitatory synapses. Aβ oligomers bind to neurite and preferentially to the postsynaptic region, where the postsynaptic protein-95 (PSD-95) is present in the glutamatergic synapse, and interacts directly with the N-methyl-D-aspartate receptor (NMDAR) and neuroligin (NL). NL is a postsynaptic protein which binds to the presynaptic protein, neurexin to form a heterophilic adhesion complex, the disruption of this interaction affects the integrity of the synaptic contact. Structurally, NL has an extracellular domain homolog to acetylcholinesterase, the first synaptic protein that was found to interact with Aβ. In the present review we will document the interaction between Aβ and the extracellular domain of NL-1 at the excitatory synapse, as well as the interaction with other postsynaptic components, including the glutamatergic receptors (NMDA and mGluR5), the prion protein, the neurotrophin receptor, and the α7-nicotinic acetylcholine receptor. We conclude that several Aβ oligomers receptors exist at the excitatory synapse, which could be the responsible for the neurotoxic effect described for the Aβ oligomers. The characterization of the interaction between Aβ receptors and Aβ oligomers could help to understand the source of the neurologic damage observed in the brain of the Alzheimer’s disease patients. PMID:23267328

  14. Contribution of inducible and neuronal nitric oxide synthases to mitochondrial damage and melatonin rescue in LPS-treated mice.

    PubMed

    García, José Antonio; Ortiz, Francisco; Miana, Javier; Doerrier, Carolina; Fernández-Ortiz, Marisol; Rusanova, Iryna; Escames, Germaine; García, José Joaquín; Acuña-Castroviejo, Darío

    2017-01-21

    NOS isoform activation is related to liver failure during sepsis, but the mechanisms driving mitochondrial impairment remain unclear. We induced sepsis by LPS administration to inducible nitric oxide synthase (iNOS(-/-)) and neuronal nitric oxide synthase (nNOS(-/-)) mice and their respective wild-type controls to examine the contribution of iNOS to mitochondrial failure in the absence of nNOS. To achieve this goal, the determination of messenger RNA (mRNA) expression and protein content of iNOS in cytosol and mitochondria, the mitochondrial respiratory complex content, and the levels of nitrosative and oxidative stress (by measuring 3-nitrotyrosine residues and carbonyl groups, respectively) were examined in the liver of control and septic mice. We detected strongly elevated iNOS mRNA expression and protein levels in liver cytosol and mitochondria of septic mice, which were related to enhanced oxidative and nitrosative stress, and with fewer changes in respiratory complexes. The absence of the iNOS, but not nNOS, gene absolutely prevented mitochondrial impairment during sepsis. Moreover, the nNOS gene did not modify the expression and the effects of iNOS here shown. Melatonin administration counteracted iNOS activation and mitochondrial damage and enhanced the expression of the respiratory complexes above the control values. These effects were unrelated to the presence or absence of nNOS. iNOS is a main target to prevent liver mitochondrial impairment during sepsis, and melatonin represents an efficient antagonist of these iNOS-dependent effects whereas it may boost mitochondrial respiration to enhance liver survival.

  15. Poly(GR) in C9ORF72-Related ALS/FTD Compromises Mitochondrial Function and Increases Oxidative Stress and DNA Damage in iPSC-Derived Motor Neurons.

    PubMed

    Lopez-Gonzalez, Rodrigo; Lu, Yubing; Gendron, Tania F; Karydas, Anna; Tran, Helene; Yang, Dejun; Petrucelli, Leonard; Miller, Bruce L; Almeida, Sandra; Gao, Fen-Biao

    2016-10-19

    GGGGCC repeat expansions in C9ORF72 are the most common genetic cause of both ALS and FTD. To uncover underlying pathogenic mechanisms, we found that DNA damage was greater, in an age-dependent manner, in motor neurons differentiated from iPSCs of multiple C9ORF72 patients than control neurons. Ectopic expression of the dipeptide repeat (DPR) protein (GR)80 in iPSC-derived control neurons increased DNA damage, suggesting poly(GR) contributes to DNA damage in aged C9ORF72 neurons. Oxidative stress was also increased in C9ORF72 neurons in an age-dependent manner. Pharmacological or genetic reduction of oxidative stress partially rescued DNA damage in C9ORF72 neurons and control neurons expressing (GR)80 or (GR)80-induced cellular toxicity in flies. Moreover, interactome analysis revealed that (GR)80 preferentially bound to mitochondrial ribosomal proteins and caused mitochondrial dysfunction. Thus, poly(GR) in C9ORF72 neurons compromises mitochondrial function and causes DNA damage in part by increasing oxidative stress, revealing another pathogenic mechanism in C9ORF72-related ALS and FTD.

  16. Comparison of the acute inhibitory effects of Tetrodotoxin (TTX) in rat and human neuronal networks for risk assessment purposes.

    PubMed

    Kasteel, Emma E J; Westerink, Remco H S

    2017-03-15

    Tetrodotoxin (TTX) is an extremely toxic marine neurotoxin. TTX inhibits voltage-gated sodium channels, resulting in a potentially lethal inhibition of neurotransmission. Despite numerous intoxications in Asia and Europe, limited (human) toxicological data are available for TTX. Additionally, the degree of interspecies differences for TTX is not well established, hampering the use of available (animal) data for human risk assessment and establishing regulatory limits for TTX concentrations in (shell)fish. We therefore used micro-electrode array (MEA) recordings as an integrated measure of neurotransmission to demonstrate that TTX inhibits neuronal electrical activity in both primary rat cortical cultures and human-induced pluripotent stem cell (hIPSC)-derived iCell(®) neurons in co-culture with hIPSC-derived iCell(®) astrocytes, with IC50 values of 7 and 10nM, respectively. From these data combined with LD50 values and IC50 concentrations of voltage-gated sodium channels derived from literature it can be concluded that interspecies differences are limited for TTX. Consequently, we used experimental animal data to derive a human acute reference dose of 1.33μg/kg body weight, which corresponds to maximum concentration of TTX in shellfish of 200μg/kg.

  17. [Cutaneous damage after acute exposure to ionizing radiation: decisive for the prognosis of radiation accident victims].

    PubMed

    Dörr, H; Baier, T; Meineke, V

    2013-12-01

    The cutaneous radiation syndrome includes all deterministic effects on the skin and visible parts of the mucosa from ionizing radiation. The Intensity and duration of radiation-induced skin symptoms depend on the kind and quality of ionizing radiation. The aim of this study was the investigation of the importance of the time of the development of radiation induced-skin effects on the prognosis of radiation accident victims. Clinical data about radiation accident victims from the database SEARCH were used. 211 cases with good documentation regarding radiation-induced skin effects were selected. From these 211 patients, 166 survived the acute phase of the acute radiation syndrome, while 45 died during the acute phase. Among those patients who did not survive the acute phase, 82.2 % showed their first documented radiation-induced skin symptoms during the first 3 days after radiation exposure. Of those patients whose first documented radiation-induced skin symptoms appeared on or after day four, 94.2 % survived the acute phase. The time to the occurrence of the first radiation-induced skin effects is diagnostically significant. The skin plays an important role in the clinical course of radiation syndromes and in the development of radiation-induced multi-organ failure. In a retrospective data analysis like this, the quality of data might be a limitation.

  18. Mesenchymal stem cell transplantation attenuates blood brain barrier damage and neuroinflammation and protects dopaminergic neurons against MPTP toxicity in the substantia nigra in a model of Parkinson's disease.

    PubMed

    Chao, Yin Xia; He, Bei Ping; Tay, Samuel Sam Wah

    2009-11-30

    Immunomodulatory effects of transplanted mesenchymal stem cells (MSCs) in the treatment of Parkinson's disease were studied in the MPTP-induced mouse model. MPTP treatment induced a significant loss of dopaminergic neurons, decreased expressions of claudin 1, claudin 5 and occludin in the substantia nigra compacta (SNc), and functional damage of the blood brain barrier (BBB). Our study further discovered that infiltration of MBLs into the brain to bind with microglia was detected in the SNc of MPTP-treated mice, suggesting that the BBB compromise and MBL infiltration might be involved in the pathogenesis of MPTP-induced PD. In addition, MPTP treatment also increased the expression of mannose-binding lectins (MBLs) in the liver tissue. Intravenous transplantation of MSCs into MPTP-treated mice led to recovery of BBB integrity, suppression of MBL infiltration at SNc and MBL expression in the liver, suppression of microglial activation and prevention of dopaminergic neuron death. No transplanted MSCs were observed to differentiate into dopaminergic neurons, while the MSCs migrated into the SNc and released TGF-beta1 there. Therefore, intravenous transplantation of MSCs which protect dopaminergic neurons from MPTP toxicity may be engaged in anyone or a combination of these mechanisms: repair of the BBB, reduction of MBL in the brain, inhibition of microglial cytotoxicity, and direct protection of dopaminergic neurons.

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-03-14

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

  1. Basic presynaptic functions in hippocampal neurons are not affected by acute or chronic lithium treatment.

    PubMed

    Lueke, Katharina; Kaiser, Tobias; Svetlitchny, Alexei; Welzel, Oliver; Wenzel, Eva M; Tyagarajan, Shiva; Kornhuber, Johannes; Groemer, Teja W

    2014-02-01

    Lithium is an effective mood-stabilizer in the treatment of bipolar affective disorder. While glycogen synthase kinase 3-mediated and inositol depletion-dependent effects of lithium have been described extensively in literature, there is very little knowledge about the consequences of lithium treatment on vesicle recycling and neurotransmitter availability. In the present study we have examined acute and chronic effects of lithium on synaptic vesicle recycling using primary hippocampal neurons. We found that exocytosis of readily releasable pool vesicles as well as recycling pool vesicles was unaffected by acute and chronic treatment within the therapeutic range or at higher lithium concentrations. Consistent with this observation, we also noticed that the network activity and number of active synapses within the network were also not significantly altered after lithium treatment. Taken together, as lithium treatment does not affect synaptic vesicle release at even high concentrations, our data suggest that therapeutic effects of lithium in bipolar affective disorder are not directly related to presynaptic function.

  2. [Clinical and immunological features of acute hepatitis B in patients with concomitant chronic toxic liver damage].

    PubMed

    Furyk, E; Ryabokon, E

    2013-02-01

    The article presents information obtained during the survey in 64 patients with acute hepatitis B. We show that acute hepatitis B in patients with concomitant chronic toxic liver characterized by a marked imbalance of cytokine status due to a lower level of interleukin-2 and a higher content of interleukin-8, the highest levels of nitrite content, spontaneous oxidative modifications of blood proteins and the lowest content of L -arginine in the blood serum in the dynamics of disease compared with patients without this concomitant factor. In the period of convalescence these changes in patients with acute hepatitis B with concomitant chronic toxic liver characterized combined with higher cytolysis of liver cells, often circulating in the blood of HBsAg seroconversion and less frequently with the advent of anti-HBeAg.

  3. SPARC (secreted protein acidic and rich in cysteine) knockdown protects mice from acute liver injury by reducing vascular endothelial cell damage

    PubMed Central

    Peixoto, E; Atorrasagasti, C; Aquino, JB; Militello, R; Bayo, J; Fiore, E; Piccioni, F; Salvatierra, E; Alaniz, L; García, MG; Bataller, R; Corrales, F; Gidekel, M; Podhajcer, O; Colombo, MI; Mazzolini, G

    2015-01-01

    Secreted protein, acidic and rich in cysteine (SPARC) is involved in many biological process including liver fibrogenesis, but its role in acute liver damage is unknown. To examine the role of SPARC in acute liver injury, we used SPARC knock-out (SPARC−/−) mice. Two models of acute liver damage were used: concanavalin A (Con A) and the agonistic anti-CD95 antibody Jo2. SPARC expression levels were analyzed in liver samples from patients with acute-on-chronic alcoholic hepatitis (AH). SPARC expression is increased on acute-on-chronic AH patients. Knockdown of SPARC decreased hepatic damage in the two models of liver injury. SPARC−/− mice showed a marked reduction in Con A-induced necroinflammation. Infiltration by CD4+ T cells, expression of tumor necrosis factor-α and interleukin-6 and apoptosis were attenuated in SPARC−/− mice. Sinusoidal endothelial cell monolayer was preserved and was less activated in Con A-treated SPARC−/− mice. SPARC knockdown reduced Con A-induced autophagy of cultured human microvascular endothelial cells (HMEC-1). Hepatic transcriptome analysis revealed several gene networks that may have a role in the attenuated liver damaged found in Con A-treated SPARC−/− mice. SPARC has a significant role in the development of Con A-induced severe liver injury. These results suggest that SPARC could represent a therapeutic target in acute liver injury. PMID:25410742

  4. SUMOylation of NaV1.2 channels mediates the early response to acute hypoxia in central neurons

    PubMed Central

    Plant, Leigh D; Marks, Jeremy D; Goldstein, Steve AN

    2016-01-01

    The mechanism for the earliest response of central neurons to hypoxia—an increase in voltage-gated sodium current (INa)—has been unknown. Here, we show that hypoxia activates the Small Ubiquitin-like Modifier (SUMO) pathway in rat cerebellar granule neurons (CGN) and that SUMOylation of NaV1.2 channels increases INa. The time-course for SUMOylation of single NaV1.2 channels at the cell surface and changes in INa coincide, and both are prevented by mutation of NaV1.2-Lys38 or application of a deSUMOylating enzyme. Within 40 s, hypoxia-induced linkage of SUMO1 to the channels is complete, shifting the voltage-dependence of channel activation so that depolarizing steps evoke larger sodium currents. Given the recognized role of INa in hypoxic brain damage, the SUMO pathway and NaV1.2 are identified as potential targets for neuroprotective interventions. DOI: http://dx.doi.org/10.7554/eLife.20054.001 PMID:28029095

  5. Nerve growth factor acts through the TrkA receptor to protect sensory neurons from the damaging effects of the HIV-1 viral protein, Vpr.

    PubMed

    Webber, C A; Salame, J; Luu, G-L S; Acharjee, S; Ruangkittisakul, A; Martinez, J A; Jalali, H; Watts, R; Ballanyi, K; Guo, G F; Zochodne, D W; Power, C

    2013-11-12

    Distal sensory polyneuropathy (DSP) with associated neuropathic pain is the most common neurological disorder affecting patients with human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS). Viral protein R (Vpr) is a neurotoxic protein encoded by HIV-1 and secreted by infected macrophages. Vpr reduces neuronal viability, increases cytosolic calcium and membrane excitability of cultured dorsal root ganglion (DRG) sensory neurons, and is associated with mechanical allodynia in vivo. A clinical trial with HIV/AIDS patients demonstrated that nerve growth factor (NGF) reduced the severity of DSP-associated neuropathic pain, a problem linked to damage to small diameter, potentially NGF-responsive fibers. Herein, the actions of NGF were investigated in our Vpr model of DSP and we demonstrated that NGF significantly protected sensory neurons from the effects of Vpr. Footpads of immunodeficient Vpr transgenic (vpr/RAG1(-/-)) mice displayed allodynia (p<0.05), diminished epidermalinnervation (p<0.01) and reduced NGF mRNA expression (p<0.001) compared to immunodeficient (wildtype/RAG1(-/-)) littermate control mice. Compartmented cultures confirmed recombinant Vpr exposure to the DRG neuronal perikarya decreased distal neurite extension (p<0.01), whereas NGF exposure at these distal axons protected the DRG neurons from the Vpr-induced effect on their cell bodies. NGF prevented Vpr-induced attenuation of the phosphorylated glycogen synthase-3 axon extension pathway and tropomyosin-related kinase A (TrkA) receptor expression in DRG neurons (p<0.05) and it directly counteracted the cytosolic calcium burst caused by Vpr exposure to DRG neurons (p<0.01). TrkA receptor agonist indicated that NGFacted through the TrkA receptor to block the Vpr-mediated decrease in axon outgrowth in neonatal and adult rat and fetal human DRG neurons (p<0.05). Similarly, inhibiting the lower affinity NGF receptor, p75, blocked Vpr's effect on DRG neurons. Overall, NGF/TrkA signaling

  6. Nerve growth factor acts through the TrkA receptor to protect sensory neurons from the damaging effects of the HIV-1 viral protein, Vpr

    PubMed Central

    Webber, Christine A.; Salame, Jihan; Luu, Gia-Linh S.; Acharjee, Shaona; Ruangkittisakul, Araya; Martinez, Jose A.; Jalali, Hanieh; Watts, Russell; Ballanyi, Klaus; Guo, Gui Fang; Zochodne, Douglas W.; Power, Christopher

    2013-01-01

    Distal sensory polyneuropathy (DSP) with associated neuropathic pain is the most common neurological disorder affecting patients with human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS). Viral protein R (Vpr) is a neurotoxic protein encoded by HIV-1 and secreted by infected macrophages. Vpr reduces neuronal viability, increases cytosolic calcium and membrane excitability of cultured dorsal root ganglion (DRG) sensory neurons, and is associated with mechanical allodynia in vivo. A clinical trial with HIV/AIDS patients demonstrated that nerve growth factor (NGF) reduced the severity of DSP-associated neuropathic pain, a problem linked to damage to small diameter, potentially NGF responsive fibers. Herein, the actions of NGF were investigated in our Vpr model of DSP and we demonstrated that NGF significantly protected sensory neurons from the effects of Vpr. Footpads of immunodeficient Vpr transgenic (vpr/RAG1−/−) mice displayed allodynia (p<0.05), diminished epidermal innervation (p<0.01) and reduced NGF mRNA expression (p<0.001) compared to immunodeficient (wildtype/RAG1−/−) littermate control mice. Compartmented cultures confirmed recombinant Vpr exposure to the DRG neuronal perikarya decreased distal neurite extension (p<0.01), whereas NGF exposure at these distal axons protected the DRG neurons from the Vpr-induced effect on their cell bodies. NGF prevented Vpr-induced attenuation of the phosphorylated glycogen synthase-3 axon extension pathway and tropomyosin related kinase A (TrkA) receptor expression in DRG neurons (p<0.05) and it directly counteracted the cytosolic calcium burst caused by Vpr exposure to DRG neurons (p<0.01). TrkA receptor antagonists indicated that NGF acted through the TrkA receptor to block the Vpr-mediated decrease in axon outgrowth in neonatal and adult rat and fetal human DRG neurons (p<0.05). Similarly, inhibiting the lower affinity NGF receptor, p75, blocked Vpr’s effect on DRG neurons. Overall, NGF

  7. Neuronal damage using fluoro-jade B histofluorescence and gliosis in the striatum after various durations of transient cerebral ischemia in gerbils.

    PubMed

    Ohk, Taek Geun; Yoo, Ki-Yeon; Park, Seung Min; Shin, Bich Na; Kim, In Hye; Park, Joon Ha; Ahn, Hee Cheol; Lee, Young Joo; Kim, Myong Jo; Kim, Tae Young; Won, Moo-Ho; Cho, Jun Hwi

    2012-04-01

    Ischemic damage occurs well in vulnerable regions of the brain, including the hippocampus and striatum. In the present study, we examined neuronal damage/death and glial changes in the striatum 4 days after 5, 10, 15 and 20 min of transient cerebral ischemia using the gerbil. Spontaneous motor activity was increased with the duration time of ischemia-reperfusion (I-R). To examine neuronal damage, we used Fluoro-Jade B (F-J B, a marker for neuronal degeneration) histofluorescence staining. F-J B positive cells were detected only in the 20 min ischemia-group, not in the other groups. In addition, we examined gliosis of astrocytes and microglia using anti-glial fibrillary acidic protein (GFAP) and anti- ionized calcium-binding adapter molecule 1 (Iba-1), respectively. In the 5 min ischemia-group, GFAP-immunoreactive astrocytes were distinctively increased in number, and the immunoreactivity was stronger than that in the sham-group. In the 10, 15 and 20 min ischemia-groups, GFAP-immunoreactivity was more increased with the duration of I-R. On the other hand, the immunoreactivity and the number of Iba-1-immunoreactive microglia were distinctively increased in the 5 and 10 min ischemia-groups. In the 15 min ischemia-group, cell bodies of microglia were largest, and the immunoreactivity was highest; however, in the 20 min ischemia-group, the immunoreactivity was low compared to the 15 min ischemia-group. The results of western blotting for GFAP and Iba-1 were similar to the immunohistochemical data. In brief, these findings showed that neuronal death could be detected only in the 20 min ischemia-group 4 days after I-R, and the change pattern of astrocytes and microglia were apparently different according to the duration time of I-R.

  8. Caspase-dependent degradation of MDMx/MDM4 cell cycle regulatory protein in amyloid β-induced neuronal damage.

    PubMed

    Colacurcio, Daniel J; Zyskind, Jacob W; Jordan-Sciutto, Kelly L; Espinoza, Cagla Akay

    2015-11-16

    MDMx/MDM4 is a negative regulator of the p53 tumor suppressor protein and is necessary for survival in dividing cells. MDMx is also expressed in postmitotic neurons, with prosurvival roles that are independent of its extensively described roles in carcinogenesis. We and others have shown a role for MDMx loss in neuronal death in vitro and in vivo in several neurodegenerative diseases. Further, we have recently shown that MDMx is targeted for proteolytic degradation by calcium-dependent proteases, calpains, in neurons in vitro, and that MDMx overexpression provided partial neuroprotection in a model of HIV-associated neurodegeneration. Here, we assessed whether amyloid β (Aβ)-induced MDMx degradation occurred in Alzheimer's Disease (AD) models. Our data shows an age-dependent reduction in MDMx levels in cholinergic neurons within the cortex of adult mice expressing the swedish mutant of the amyloid precursor protein, APP in the Tg2576 murine model of AD. In vitro, Aβ treatment of primary cortical neurons led to the caspase-dependent MDMx degradation. Our findings suggest that MDMx degradation associated with neuronal death occurs via caspase activation in neurons, and that the progressive loss of MDMx protein represents a potential mechanism of Aβ-induced neuronal death during disease progression in AD.

  9. Biological Signatures of Brain Damage Associated with High Serum Ferritin Levels in Patients with Acute Ischemic Stroke and Thrombolytic Treatment

    PubMed Central

    Millán, Mónica; Sobrino, Tomás; Arenillas, Juan Francisco; Rodríguez-Yáñez, Manuel; García, María; Nombela, Florentino; Castellanos, Mar; de la Ossa, Natalia Pérez; Cuadras, Patricia; Serena, Joaquín; Castillo, José; Dávalos, Antoni

    2008-01-01

    Background and purpose: Increased body iron stores have been related to greater oxidative stress and brain injury in clinical and experimental cerebral ischemia and reperfusion. We aimed to investigate the biological signatures of excitotoxicity, inflammation and blood brain barrier disruption potentially associated with high serum ferritin levels-related damage in acute stroke patients treated with i.v. t-PA. Methods: Serum levels of ferritin (as index of increased cellular iron stores), glutamate, interleukin-6, matrix metalloproteinase-9 and cellular fibronectin were determined in 134 patients treated with i.v. t-PA within 3 hours from stroke onset in blood samples obtained before t-PA treatment, at 24 and 72 hours. Results: Serum ferritin levels before t-PA infusion correlated to glutamate (r = 0.59, p < 0.001) and interleukin-6 (r = 0.55, p <0.001) levels at baseline, and with glutamate (r = 0.57,p <0.001), interleukin-6 (r = 0.49,p <0.001), metalloproteinase-9 (r = 0.23, p = 0.007) and cellular fibronectin (r = 0.27, p = 0.002) levels measured at 24 hours and glutamate (r = 0.415, p < 0.001), interleukin-6 (r = 0.359, p < 0.001) and metalloproteinase-9 (r = 0.261, p = 0.004) at 72 hours. The association between ferritin and glutamate levels remained after adjustment for confounding factors in generalized linear models. Conclusions: Brain damage associated with increased iron stores in acute ischemic stroke patients treated with iv. tPA may be mediated by mechanisms linked to excitotoxic damage. The role of inflammation, blood brain barrier disruption and oxidative stress in this condition needs further research. PMID:19096131

  10. Effects of extracellular delta-aminolaevulinic acid on sodium currents in acutely isolated rat hippocampal CA1 neurons.

    PubMed

    Wang, Lang; Yan, Dan; Gu, Yan; Sun, Li-Guang; Ruan, Di-Yun

    2005-12-01

    The effects of delta-aminolaevulinic acid (ALA) on voltage-gated sodium channel (VGSC) currents (I(Na)) in acutely isolated hippocampal CA1 neurons from 10- to 12-day-old Wistar rats were examined by using the whole-cell patch-clamp technique under voltage-clamp conditions. ALA from 0.01 microm to 20 microm was applied to the recorded neurons. Low concentrations of ALA (0.01-1.0 microM) increased I(Na) amplitude, whereas high concentrations of ALA (5.0-20.0 microM) decreased it. The average I(Na) amplitude reached a maximum of 117.4 +/- 3.9% (n = 9, P < 0.05) with 0.1 microM ALA, and decreased to 78.1 +/- 3.8% (n = 13, P < 0.05) with 10 microm ALA. ALA shifted the steady-state activation and inactivation curves of I(Na) in the hyperpolarizing direction with different V0.5, suggesting that ALA could depress the opening threshold of the voltage-gated sodium channel (VGSC) and thus increase the excitability of neurons through facilitating the opening of VGSC. The time course of recovery from inactivation was significantly prolonged at both low and high concentrations of ALA, whereas either low or high concentrations of ALA had no significant effect on the attenuation of I(Na) during stimulation at 5 Hz, indicating that the effect of ALA on VGSC is state-independent. Furthermore, we found that application of ascorbic acid, which blocks pro-oxidative effects in neurons, could prevent the increase of I(Na) amplitude at low concentrations of ALA. Baclofen, an agonist of GABAb receptors, induced some similar effects to ALA on VGSC, whereas bicuculline, an antagonist of GABAa receptors, could not prevent ALA-induced effects on VGSC. These results suggested that ALA regulated VGSC mainly through its pro-oxidative effects and GABAb receptor-mediated effects.

  11. Neuronal damage by secretory phospholipase A2: modulation by cytosolic phospholipase A2, platelet-activating factor, and cyclooxygenase-2 in neuronal cells in culture.

    PubMed

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

    2003-02-27

    Activation of cytosolic phospholipase A(2) (cPLA(2)) is an early event in brain injury, which leads to the formation and accumulation of bioactive lipids: platelet-activating factor (PAF), free arachidonic acid, and eicosanoids. A cross-talk between secretory PLA(2) (sPLA(2)) and cPLA(2) in neural signal transduction has previously been suggested (J Biol Chem 271:32722; 1996). Here we show, using neuronal cell cultures, an up-regulation of cPLA(2) expression and an inhibition by the selective cPLA(2) inhibitor AACOCF3 after exposure to neurotoxic concentrations of sPLA(2)-OS2. Pretreatment of neuronal cultures with recombinant PAF acetylhydrolase (rPAF-AH) or the presynaptic PAF receptor antagonist, BN52021, partially blocked neuronal cell death induced by sPLA(2)-OS2. Furthermore, selective COX-2 inhibitors ameliorated sPLA(2)-OS2-induced neurotoxicity. We conclude that sPLA(2)-OS2 activates a neuronal signaling cascade that includes activation of cPLA(2), arachidonic acid release, PAF production, and induction of COX-2.

  12. Acute hyperglycemia worsens ischemic stroke-induced brain damage via high mobility group box-1 in rats.

    PubMed

    Huang, Jingyang; Liu, Baoyi; Yang, Chenghui; Chen, Haili; Eunice, Dzivor; Yuan, Zhongrui

    2013-10-16

    Hyperglycemia adversely affects the outcome of ischemic stroke. Extracellular HMGB1 plays a role in aggravating brain damage in the postischemic brain. The aim of this study was to determine whether the extracellular HMGB1 is involved in the worsened ischemic damage during hyperglycemic stroke. Male Wistar rats underwent middle cerebral artery occlusion (MCAO) for 90 min with reperfusion. Acute hyperglycemia was induced by an injection of 50% dextrose. Rats received glycyrrhizin, a specific HMGB1 inhibitor, or vehicle. HMGB-1 in cerebrospinal fluid and in brain parenchyma was detected at 2 or 4 h post-reperfusion. Neurological deficits, infarct volume and cerebral edema were assessed 24 h post-MCAO the disruption of blood-brain barrier (BBB) and the expression of tight junction protein Occludin were measured at 4 h post-reperfusion. Hyperglycemia enhanced the early release of HMGB1 from ischemic brain tissue, which was accompanied by increased infarct volume, neurological deficit, cerebral edema and BBB disruption. Glycyrrhizin alleviated the aggravation of infarct volume, neurological deficit, cerebral edema and BBB disruption by decreasing the degradation of tight junction protein Occludin in the ischemic hemisphere of hyperglycemic rats. In conclusion, enhanced early extracellular release of HMGB1 might represent an important mechanism for worsened ischemic damage, particularly early BBB disruption, during hyperglycemic stroke. An HMGB1 inhibitor glycyrrhizin is a potential therapeutic option for hyperglycemic stroke.

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

    PubMed

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

    2014-11-15

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

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

    PubMed Central

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

    2015-01-01

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

  15. Acute changes of serum markers for tissue damage after ESWL of kidney stones.

    PubMed

    Apostolov, I; Minkov, N; Koycheva, M; Isterkov, M; Abadjyev, M; Ondeva, V; Trendafilova, T

    1991-01-01

    Seventeen serum markers (including 9 enzyme activities) for eventual tissue damage were studied after ESWL in 40 patients with unilateral kidney calculosis. No changes were established in the 8 non-enzymic parameters and the activities of amylase, lipase, AST (GOT), ALT (GPT) and CK-MB. A statistically significant increase was found in LDH, alpha-HBDH, CK (twice) and glutamate dehydrogenase (3 times). The slight elevation of LDH and alpha-HBDH could be due to haemolysis caused by the shock waves. Increased activity of CK suggested myolysis and that of GlDH a hepatocellular damage.

  16. Early activation of nSMase2/ceramide pathway in astrocytes is involved in ischemia-associated neuronal damage via inflammation in rat hippocampi

    PubMed Central

    2013-01-01

    Background Ceramide accumulation is considered a contributing factor to neuronal dysfunction and damage. However, the underlying mechanisms that occur following ischemic insult are still unclear. Methods In the present study, we established cerebral ischemia models using four-vessel occlusion and oxygen-glucose deprivation methods. The hippocampus neural cells were subjected to immunohistochemistry and immunofluorescence staining for ceramide and neutral sphingomyelinase 2 (nSMase2) levels; immunoprecipitation and immunoblot analysis for nSMase2, receptor for activated C kinase 1 (RACK1), embryonic ectoderm development (EED), p38 mitogen-activated protein kinase (p38MAPK) and phosphorylated p38MAPK expression; SMase assay for nSMase and acid sphingomyelinase (aSMase) activity; real-time reverse transcription polymerase chain reaction for cytokine expression; and Nissl, microtubule-associated protein 2 and terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick-end labeling staining. Results We found considerable production of ceramide in astrocytes, but not in neurons, during early cerebral ischemia. This was accompanied by the induction of nSMase (but not aSMase) activity in the rat hippocampi. The inhibition of nSMase2 activity effectively reduced ceramide accumulation in astrocytes and alleviated neuronal damage to some extent. Meanwhile, the expression levels of proinflammatory cytokines, including tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β) and IL-6, were found to be upregulated, which may have played an import role in neuronal damage mediated by the nSMase2/ceramide pathway. Although enhanced binding of nSMase2 with RACK1 and EED were also observed after cerebral ischemia, nSMase2 activity was not blocked by the TNF-α receptor inhibitor through RACK1/EED signaling. p38MAPK, but not protein kinase Cζ or protein phosphatase 2B, was able to induce nSMase2 activation after ischemia. p38MAPK can be induced by A2B adenosine

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2015-11-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-07-21

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

  1. Neuroprotective effects of Cyperus rotundus on SIN-1 induced nitric oxide generation and protein nitration: ameliorative effect against apoptosis mediated neuronal cell damage.

    PubMed

    Hemanth Kumar, Kandikattu; Tamatam, Anand; Pal, Ajay; Khanum, Farhath

    2013-01-01

    Nitrosylation of tyrosine (3-nitro tyrosine, 3-NT) has been implicated in the pathophysiology of various disorders particularly neurodegenerative conditions and aging. Cyperus rotundus rhizome is being used as a traditional folk medicine to alleviate a variety of disorders including neuronal stress. The herb has recently found applications in food and confectionary industries also. In current study, we have explored the protective effects of C. rotundus rhizome extract (CRE) through its oxido-nitrosative and anti apoptotic mechanism to attenuate peroxynitrite (ONOO(-)) induced neurotoxicity using human neuroblastoma SH-SY5Y cells. Our results elucidate that pre-treatment of neurons with CRE ameliorates the mitochondrial and plasma membrane damage induced by 500 μM SIN-1 to 80% and 24% as evidenced by MTT and LDH assays. CRE inhibited NO generation by downregulating i-NOS expression. SIN-1 induced depletion of antioxidant enzyme status was also replenished by CRE which was confirmed by immunoblot analysis of SOD and CAT. The CRE pre-treatment efficiently potentiated the SIN-1 induced apoptotic biomarkers such as bcl-2 and caspase-3 which orchestrate the proteolytic damage of the cell. The ONOO(-) induced damage to cellular, nuclear and mitochondrial integrity was also restored by CRE. Furthermore, CRE pre-treatment also regulated the 3-NT formation which shows the potential of plant extract against tyrosine nitration. Taken together, our findings suggest that CRE might be developed as a preventive agent against ONOO(-) induced apoptosis.

  2. PBDE-209 exposure damages learning and memory ability in rats potentially through increased autophagy and apoptosis in the hippocampus neuron.

    PubMed

    Sun, Wen; Du, Lili; Tang, Wenting; Kuang, Liyun; Du, Peili; Chen, Jingsi; Chen, Dunjin

    2017-03-01

    This study is to investigate the neurotoxicity of PBDE-209 during pregnancy through autophagy and apoptosis in the fetal hippocampus neuron. The autophagy protein levels of LC3-II and Beclin-1 were significantly higher in hippocampus tissue and neuron, while P62 protein were lower. Apoptosis protein Cleaved Caspase-3 and Cleaved PARP was significantly higher in PBDE dose groups and BCL-2 levels in high PBDE dose groups were significantly lower. During the Morris water maze task, the escape latency times of high PBDE dose groups were significantly longer. PBDE-209-induced autophagy leads to neurons death and inhibition of autophagy reduce PBDE-209-induced apoptotic cell death. These results suggest that exposure of the PBDE-209 during pregnancy increases hippocampal autophagy, decrease neuron viability, and it partly effect apoptosis induced by PBDE-209. All that may contribute to the decline of learning and memory ability in the offspring.

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

    PubMed

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

    2015-11-01

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

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

    SciTech Connect

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

    2012-06-15

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

  5. 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

    2015-08-07

    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.

  6. Hepatoprotective effect of Vitis vinifera L. leaves on carbon tetrachloride-induced acute liver damage in rats.

    PubMed

    Orhan, Didem Deliorman; Orhan, Nilüfer; Ergun, Ender; Ergun, Fatma

    2007-05-30

    The hepatoprotective effect of ethanolic extract and its four different fractions (CHCl(3), EtOAc, n-BuOH, and remaining water fraction) of Vitis vinifera L. leaves was investigated against carbon tetrachloride (CCl(4))-induced acute hepatotoxicity in rats. The ethanolic extract was found active at 125mg/kg dose (per os). The ethanolic extract was fractionated through successive solvent-solvent extractions and the n-BuOH fraction in 83mg/kg dose possessed remarkable antioxidant and hepatoprotective activities. Liver damage was assessed by using biochemical parameters (plasma and liver tissue MDA [malondialdehyde], transaminase enzyme levels in plasma [AST-aspartate transaminase, ALT-alanine transferase] and liver GSH [glutathione] levels). Additionally, the pathological changes in liver were evaluated by histopathological studies. Legalon 70 Protect was used as standard natural originated drug.

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

    PubMed Central

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

    2015-01-01

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

  8. Brief anoxia preconditioning and HIF prolyl-hydroxylase inhibition enhances neuronal resistance in organotypic hippocampal slices on model of ischemic damage.

    PubMed

    Lushnikova, Iryna; Orlovsky, Maxim; Dosenko, Victor; Maistrenko, Anastasiia; Skibo, Galina

    2011-04-22

    It is well known that a brief anoxia or hypoxia episodes can render brain resistant to a subsequent ischemia. Recent investigations indicate that mechanisms of such stimulated endogenous neuroprotection are related to the family of hypoxia-inducible factors (HIF), however there are still little data available on the role of HIF family members in hippocampus-a brain structure, highly sensitive to oxygen deficiency. We have used the model of cultured hippocampal slices and single-cell quantitative RT-PCR to study HIF-1α and HIF-3α mRNA expression following triple 5-min mild anoxia, 30-min oxygen-glucose deprivation and their combination. We also tested the effects of HIF prolyl-hydroxylase inhibition with 2,4-pyridinedicarboxylic acid diethyl ester pre-treatment followed by a 30-min oxygen-glucose deprivation. It was found that neuronal damage induced by oxygen-glucose deprivation was accompanied by a significant decrease in both HIF-1α and HIF-3α mRNA levels in CA1 but not CA3 neurons. Anoxia preconditioning did not affect cell viability and HIF mRNA levels but applied before oxygen-glucose deprivation prevented neuronal damage and suppression of HIF-1α and HIF-3α mRNA expression. It was also found that effects of the prolyl-hydroxylase inhibitor were similar to anoxia preconditioning. These results suggest that anoxia preconditioning increases anti-ischemic neuronal resistance which to a certain extent correlates with the changes of HIF-1α and HIF-3α expression.

  9. Prostaglandin E(2) inhibits calcium current in two sub-populations of acutely isolated mouse trigeminal sensory neurons.

    PubMed

    Borgland, Stephanie L; Connor, Mark; Ryan, Renae M; Ball, Helen J; Christie, MacDonald J

    2002-03-01

    Prostaglandins are important mediators of pain and inflammation. We have examined the effects of prostanoids on voltage-activated calcium currents (I(Ca)) in acutely isolated mouse trigeminal sensory neurons, using standard whole cell voltage clamp techniques. Trigeminal neurons were divided into two populations based on the presence (Type 2) or absence (Type 1) of low voltage-activated T-type I(Ca). The absence of T-type I(Ca) is highly correlated with sensitivity to mu-opioid agonists and the VR1 agonist capsaicin. In both populations of cells, high voltage-activated I(Ca) was inhibited by PGE(2) with an EC(50) of about 35 nM, to a maximum of 30 %. T-type I(Ca) was not inhibited by PGE(2). Pertussis toxin pre-treatment abolished the effects of PGE(2) in Type 2 cells, but not in Type 1 cells, whereas treatment with cholera toxin prevented the effects of PGE(2) in Type 1 cells, but not in Type 2 cells. Inhibition of I(Ca) by PGE(2) was associated with slowing of current activation and could be relieved with a large positive pre-pulse, consistent with inhibition of I(Ca) by G protein betagamma subunits. Reverse transcription-polymerase chain reaction of mRNA from trigeminal ganglia indicated that all four EP prostanoid receptors were present. However, in both Type 1 and Type 2 cells the effects of PGE(2) were only mimicked by the selective EP(3) receptor agonist ONO-AE-248, and not by selective agonists for EP(1) (ONO-DI-004), EP(2) (ONO-AE1-259) and EP(4) (ONO-AE1-329) receptors. These data indicate that two populations of neurons in trigeminal ganglia differing in their calcium channel expression, sensitivity to mu-opioids and capsaicin also have divergent mechanisms of PGE(2)-mediated inhibition of calcium channels, with Gi/Go type G proteins involved in one population, and Gs type G proteins in the other.

  10. Coagulopathy in patients with acute pulmonary embolism: a pilot study of whole blood coagulation and markers of endothelial damage.

    PubMed

    Lehnert, Per; Johansson, Pär I; Ostrowski, Sisse R; Møller, Christian H; Bang, Lia E; Olsen, Peter Skov; Carlsen, Jørn

    2017-02-01

    Whole blood coagulation and markers of endothelial damage were studied in patients with acute pulmonary embolism (PE), and evaluated in relation to PE severity. Twenty-five patients were enrolled prospectively each having viscoelastical analysis of whole blood done using thrombelastography (TEG) and Multiplate aggregometry. Fourteen of these patients were investigated for endothelial damage by ELISA measurements of Syndecan-1 (endothelial glycocalyx degradation), soluble endothelial Selectin (endothelial cell activation), soluble Thrombomodulin (endothelial cell injury) and Histone Complexed DNA fragments (endothelial cytotoxic histones). The mean values of TEG and Multiplate parameters were all within the reference levels, but a significant difference between patients with high and intermediate risk PE was observed for Ly30 (lytic activity) 1.5% [0-10] vs. 0.2% [0-2.2] p = .04, and ADP (platelet reactivity) 92 U [20-145] vs. 59 U [20-111] p = .03. A similar difference was indicated for functional fibrinogen 21 mm [17-29] vs. 18 mm [3-23] p = .05. Analysis of endothelial markers identified a significant difference in circulating levels between high and intermediate risk PE patients for Syndecan-1 118.6 ng/mL [76-133] vs. 36.3 ng/mL [11.8-102.9] p = .008. In conclusion, patients with acute PE had normal whole blood coagulation, but high risk PE patients had signs of increased activity of the haemostatic system and significantly increased level of endothelial glycocalyx degradation.

  11. Evaluating Radioprotective Effect of Hesperidin on Acute Radiation Damage in the Lung Tissue of Rats

    PubMed Central

    Rezaeyan, A.; Fardid, R.; Haddadi, G.H.; Takhshid, M.A.; Hosseinzadeh, M.; Najafi, M.; Salajegheh, A.

    2016-01-01

    Background: Oxidative stress plays an important role in the pathogenesis and progression of γ-irradiation-induced cellular damage, Lung is a radiosensitive organ and its damage is a dose-limiting factor in radiotherapy. The administration of dietary antioxidants has been suggested to protect against the succeeding tissue damage. The present study aimed to evaluate the radioprotective efficacy of Hesperidin (HES) against γ-irradiation-induced tissue damage in the lung of male rats. Materials and Methods: Thirty two rats were divided into four groups. Rats in Group 1 received PBS and underwent sham irradiation. Rats in Group 2 received HES and underwent sham irradiation. Rats in Group 3 received PBS and underwent γ-irradiation. Rats in Group 4 received HES and underwent γ-irradiation. These rats were exposed to γ-radiation 18 Gy using a single fraction cobalt-60 unit, and were administered HES (100 mg/kg/d, b.w, orally) for 7 days prior to irradiation. Rats in each group were sacrificed 24 hours after radiotherapy (RT) for the determination of superoxide dismutase (SOD), glutathione (GSH), malondialdehyde (MDA) and histopathological evaluations. Results: Compared to group 1, the level of SOD and GSH significantly decreased and MDA level significantly increased in group 3 at 24 h following irradiation, (p=0.001, p<0.001, p=0.001), respectively. A statistically significant difference in all parameters was observed for rats in group 4 as compared to group 3 (p<0.05). Histopathological results 24 hours after RT showed that radiation has increased inflammation, lymphocyte, macrophage and neutrophil compared to group 1 ( p<0.0125). Oral administration of HES before RT significantly decreased macrophage and neutrophil when compared to group 3 (p<0.0125), but partly there was inflammation and lymphocyte that indicated there was no significant difference when compared to group 3 (p>0.0125). Conclusion: Oral administration of HES was found to offer protection against

  12. A Growth Factor Attenuates HIV-1 Tat and Morphine Induced Damage to Human Neurons: Implication in HIV/AIDS-Drug Abuse Cases

    PubMed Central

    Malik, Shaily; Khalique, Hena; Buch, Shilpa; Seth, Pankaj

    2011-01-01

    The neuropathological abnormalities of human immunodeficiency virus (HIV)-1 patients abusing illicit drugs suggest extensive interactions between the two agents, thereby leading to increased rate of progression to neurodegeneration. The role of HIV-1 transactivating protein, Tat has been elucidated in mediating neuronal damage via apoptosis, a hallmark of HIV-associated dementia (HAD), however the underlying mechanisms involved in enhanced neurodegeneration by illicit drugs remain elusive. In this study, we demonstrated that morphine enhances HIV-Tat induced toxicity in human neurons and neuroblastoma cells. Enhanced toxicity by Tat and morphine was accompanied by increased numbers of TUNEL positive apoptotic neurons, elevated caspase-3 levels and decreased ratio of anti- and pro-apoptotic proteins, Bcl2/Bax. Tat and morphine together elicited high levels of reactive oxygen species that were NADPH dependent. Significant alterations in mitochondrial membrane homeostasis were also observed with co-exposure of these agents. Extensive studies of mitogen activated protein kinase (MAPK) signaling pathways revealed the involvement of c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase-1/2 (ERK1/2) pathways in enhanced toxicity of Tat and morphine. In addition to this, we found that pre-treatment of cells with platelet derived growth factor (PDGF-BB) protected neurons from HIV-Tat and morphine induced damage. PDGF-BB alleviated ROS production, maintained mitochondrial membrane potential, decreased caspase-3 activation and hence protected the cells from undergoing apoptosis. PDGF-BB mediated protection against Tat and morphine involved the phosphatidylinositol–3 kinase (PI3K) pathway, as specific inhibitor of PI3K abrogated the protection conferred by PDGF-BB. This study demonstrates the mechanism of enhanced toxicity in human neurons subjected to co-exposure of HIV protein Tat and morphine, thus implying its importance in HIV positive drug abusers

  13. Acute reduction of neuronal RNA binding Elavl2 protein and Gap43 mRNA in mouse hippocampus after kainic acid treatment.

    PubMed

    Ohtsuka, Takafumi; Yano, Masato; Okano, Hideyuki

    2015-10-09

    Activity-dependent gene regulation in neurons has been hypothesized to be under transcriptional control and to include dramatic increases in immediate early genes (IEGs) after neuronal activity. In addition, several reports have focused on post-transcriptional regulation, which could be mediated by neuronal post-transcriptional regulators, including RNA binding proteins (RNABPs). One such protein family is the neuronal Elavls (nElavls; Elavl2, Elavl3, and Elavl4), whose members are widely expressed in peripheral and central nervous system. Previous reports showed that Elavl3 and 4 are up-regulated following repeated stimulation such as during cocaine administration, a seizure, or a spatial discrimination task. In this study, we focused on Elavl2, a candidate gene for schizophrenia and studied its role in neuronal activity. First we found that Elavl2 has a cell-type specific expression pattern that is highly expressed in hippocampal CA3 pyramidal neurons and hilar interneurons using Elavl2 specific antibody. Second, unexpectedly, we discovered that the Elavl2 protein level in the hippocampus was acutely down-regulated for 3 h after a kainic acid (KA)-induced seizure in the hippocampal CA3 region. In addition, level of Gap43 mRNA, a target mRNA of Elavl2 is decreased 12 h after KA treatment, thus suggesting the involvement of Elavl2 in activity-dependent RNA regulation.

  14. Acute Oxidative Effect and Muscle Damage after a Maximum 4 Min Test in High Performance Athletes.

    PubMed

    Ferreira, Heros Ribeiro; Ferreira, Pamela Gill; Loures, João Paulo; Fernandes Filho, José; Fernandes, Luiz Cláudio; Buck, Hudson Sousa; Montor, Wagner Ricardo

    2016-01-01

    The purpose of this investigation was to determine lipid peroxidation markers, physiological stress and muscle damage in elite kayakers in response to a maximum 4-min kayak ergometer test (KE test), and possible correlations with individual 1000m kayaking performances. The sample consisted of twenty-three adult male and nine adult female elite kayakers, with more than three years' experience in international events, who voluntarily took part in this study. The subjects performed a 10-min warm-up, followed by a 2-min passive interval, before starting the test itself, which consisted of a maximum 4-min work paddling on an ergometer; right after the end of the test, an 8 ml blood sample was collected for analysis. 72 hours after the test, all athletes took part in an official race, when then it was possible to check their performance in the on site K1 1000m test (P1000m). The results showed that all lipoproteins and hematological parameters tested presented a significant difference (p≤0.05) after exercise for both genders. In addition, parameters related to muscle damage such as lactate dehydrogenase (LDH) and creatine kinase (CK) presented significant differences after stress. Uric acid presented an inverse correlation with the performance (r = -0.76), while CK presented a positive correlation (r = 0.46) with it. Based on these results, it was possible to verify muscle damage and the level of oxidative stress caused by indoor training with specific ergometers for speed kayaking, highlighting the importance of analyzing and getting to know the physiological responses to this type of training, in order to provide information to coaches and optimize athletic performance.

  15. Acute Oxidative Effect and Muscle Damage after a Maximum 4 Min Test in High Performance Athletes

    PubMed Central

    Fernandes Filho, José; Fernandes, Luiz Cláudio

    2016-01-01

    The purpose of this investigation was to determine lipid peroxidation markers, physiological stress and muscle damage in elite kayakers in response to a maximum 4-min kayak ergometer test (KE test), and possible correlations with individual 1000m kayaking performances. The sample consisted of twenty-three adult male and nine adult female elite kayakers, with more than three years’ experience in international events, who voluntarily took part in this study. The subjects performed a 10-min warm-up, followed by a 2-min passive interval, before starting the test itself, which consisted of a maximum 4-min work paddling on an ergometer; right after the end of the test, an 8 ml blood sample was collected for analysis. 72 hours after the test, all athletes took part in an official race, when then it was possible to check their performance in the on site K1 1000m test (P1000m). The results showed that all lipoproteins and hematological parameters tested presented a significant difference (p≤0.05) after exercise for both genders. In addition, parameters related to muscle damage such as lactate dehydrogenase (LDH) and creatine kinase (CK) presented significant differences after stress. Uric acid presented an inverse correlation with the performance (r = -0.76), while CK presented a positive correlation (r = 0.46) with it. Based on these results, it was possible to verify muscle damage and the level of oxidative stress caused by indoor training with specific ergometers for speed kayaking, highlighting the importance of analyzing and getting to know the physiological responses to this type of training, in order to provide information to coaches and optimize athletic performance. PMID:27111088

  16. Local application of L- threo-hydroxyaspartate and malonate in rats in vivo induces rigidity and damages neurons of the substantia nigra, pars compacta.

    PubMed

    Loopuijt, L D

    2002-10-01

    In order to study neuronal death in Parkinson's disease, neurons of the substantia nigra, pars compacta in rats were exposed to elevated levels of glutamate and decreased levels of energy in vivo and consequences for behavior and neuronal morphology were studied. Thus, repeated local injections (9x) of the glutamate uptake inhibitor L- threo-hydroxyaspartate (L-THA; 833 microM in 0.3 microl) in the presence or absence of the succinate dehydrogenase inhibitor malonate (25 mM in 0.3 microl) were applied during three weeks. 24 h after injection, rigidity and catalepsy were measured, as well as, at the end of the three week period, locomotion, rearing and exploratory behavior. Thereafter, the cytoarchitecture of the substantia nigra, pars compacta of the brains of these rats was described. The L-THA plus malonate injected rats did not differ in their behavior from carrier injected rats, except for rigidity: their scores were higher than that of carrier and L-THA injected rats (P < 0.05), while L-THA injected rats did not differ from carrier injected controls. Observations on cresyl violet sections revealed, that, although many neurons with a shrunken nucleolus and faintly stained cytoplasm were present in both L-THA and L-THA plus malonate treated rats, the ventral edge of the substantia nigra, pars compacta containing modified cells was longer in L-THA plus malonate than in L-THA injected rats (P < 0.05). This indicates, that a minimum amount of damage to neurons in the ventral part of the substantia nigra, pars compacta might be required for the expression of rigidity.

  17. Acetylcholinesterase-independent protective effects of huperzine A against iron overload-induced oxidative damage and aberrant iron metabolism signaling in rat cortical neurons

    PubMed Central

    Tao, Ling-xue; Huang, Xiao-tian; Chen, Yu-ting; Tang, Xi-can; Zhang, Hai-yan

    2016-01-01

    Aim: Iron dyshomeostasis is one of the primary causes of neuronal death in Alzheimer's disease (AD). Huperzine A (HupA), a natural inhibitor of acetylcholinesterase (AChE), is a licensed anti-AD drug in China and a nutraceutical in the United Sates. Here, we investigated the protective effects of HupA against iron overload-induced injury in neurons. Methods: Rat cortical neurons were treated with ferric ammonium citrate (FAC), and cell viability was assessed with MTT assays. Reactive oxygen species (ROS) assays and adenosine triphosphate (ATP) assays were performed to assess mitochondrial function. The labile iron pool (LIP) level, cytosolic-aconitase (c-aconitase) activity and iron uptake protein expression were measured to determine iron metabolism changes. The modified Ellman's method was used to evaluate AChE activity. Results: HupA significantly attenuated the iron overload-induced decrease in neuronal cell viability. This neuroprotective effect of HupA occurred concurrently with a decrease in ROS and an increase in ATP. Moreover, HupA treatment significantly blocked the upregulation of the LIP level and other aberrant iron metabolism changes induced by iron overload. Additionally, another specific AChE inhibitor, donepezil (Don), at a concentration that caused AChE inhibition equivalent to that of HupA negatively, influenced the aberrant changes in ROS, ATP or LIP that were induced by excessive iron. Conclusion: We provide the first demonstration of the protective effects of HupA against iron overload-induced neuronal damage. This beneficial role of HupA may be attributed to its attenuation of oxidative stress and mitochondrial dysfunction and elevation of LIP, and these effects are not associated with its AChE-inhibiting effect. PMID:27498774

  18. Myocardial changes in acute Trypanosoma cruzi infection. Ultrastructural evidence of immune damage and the role of microangiopathy.

    PubMed Central

    Andrade, Z. A.; Andrade, S. G.; Correa, R.; Sadigursky, M.; Ferrans, V. J.

    1994-01-01

    Histological and ultrastructural studies of the hearts of dogs sacrificed 18 to 26 days after intraperitoneal inoculation with 4 x 10(5) blood forms of the 12 SF strain of Trypanosoma cruzi/kg of body weight disclosed myocarditis characterized by parasitic invasion of some myocytes, damage and necrosis of nonparasitized myocytes, and interstitial infiltration by mononuclear cells. Nonparasitized myocytes showed alterations ranging from mild edema to severe myocytolysis. These changes often were accompanied by contacts of myocytes with lymphocytes (both granular and agranular) and macrophages. These contacts were characterized by focal loss of the myocyte basement membrane and close approximation of the plasma membranes of the two cells. Contacts between lymphocytes and capillary endothelial cells were also frequent. Platelet aggregates and fibrin microthrombi were observed in some capillaries. Our findings suggest that immune effector cells play a major role in the pathogenesis of the myocyte damage and the microangiopathy in acute Chagas' disease. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 PMID:8203476

  19. Serum neuron-specific enolase levels are upregulated in patients with acute lymphoblastic leukemia and are predictive of prognosis

    PubMed Central

    Wang, Liang; Geng, Qi-rong; Chen, Xiao-qin; Lu, Yue

    2016-01-01

    We explored the relationship between neuron-specific enolase (NSE) levels and the clinical features of acute lymphoblastic leukemia (ALL). Seventy ALL patients and forty-two healthy controls were enrolled in this study, and their serum NSE levels were measured using an electrochemiluminescence assay. The serum NSE concentration was higher in ALL patients than in healthy controls. In ALL patients, the mean serum NSE level declined after complete remission (CR) but increased with relapse. In addition, the mean serum NSE level was lower in the CR group than in the non-CR group. High NSE levels were associated with poorer progression-free and overall survival than low NSE levels. Serum NSE levels closely correlated with several clinical features, including the immunophenotype, risk stratification and serum lactate dehydrogenase levels. Multivariate analysis revealed that high NSE expression was an independent prognostic factor in adult ALL patients. NSE mRNA levels were also higher in ALL cell lines and bone marrow mononuclear cells from ALL patients than in control cells. These results suggested that NSE could be a clinical prognostic factor and a potential therapeutic target in ALL. PMID:27409171

  20. Indicators of Acute and Persistent Renal Damage in Adult Thrombotic Microangiopathy

    PubMed Central

    Sucker, Christoph; Kuhr, Kathrin; Hollenbeck, Markus; Hetzel, Gerd R.; Burst, Volker; Teschner, Sven; Rump, Lars C.; Benzing, Thomas; Grabensee, Bernd; Kurschat, Christine E.

    2012-01-01

    Background Thrombotic microangiopathies (TMA) in adults such as thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS) are life-threatening disorders if untreated. Clinical presentation is highly variable and prognostic factors for clinical course and outcome are not well established. Methods We performed a retrospective observational study of 62 patients with TMA, 22 males and 40 females aged 16 to 76 years, treated with plasma exchange at one center to identify clinical risk factors for the development of renal insufficiency. Results On admission, 39 of 62 patients (63%) had acute renal failure (ARF) with 32 patients (52%) requiring dialysis treatment. High systolic arterial pressure (SAP, p = 0.009) or mean arterial pressure (MAP, p = 0.027) on admission was associated with acute renal failure. Patients with SAP>140 mmHg on admission had a sevenfold increased risk of severe kidney disease (OR 7.464, CI 2.097–26.565). MAP>100 mmHg indicated a fourfold increased risk for acute renal failure (OR 4.261, CI 1.400–12.972). High SAP, diastolic arterial pressure (DAP), and MAP on admission were also independent risk factors for persistent renal insufficiency with the strongest correlation for high MAP. Moreover, a high C-reactive protein (CRP) level on admission correlated with renal failure in the course of the disease (p = 0.003). At discharge, renal function in 11 of 39 patients (28%) had fully recovered, 14 patients (23%) remained on dialysis, and 14 patients (23%) had non-dialysis-dependent chronic kidney disease. Seven patients (11%) died. We identified an older age as risk factor for death. Conclusions High blood pressure as well as high CRP serum levels on admission are associated with renal insufficiency in TMA. High blood pressure on admission is also a strong predictor of sustained renal insufficiency. Thus, adult TMA patients with high blood pressure may require special attention to prevent persistent renal failure

  1. Metabotropic glutamate response in acutely dissociated hippocampal CA1 pyramidal neurones of the rat.

    PubMed Central

    Shirasaki, T; Harata, N; Akaike, N

    1994-01-01

    1. The metabotropic glutamate (mGlu) response was investigated in dissociated rat hippocampal CA1 pyramidal neurones using conventional and nystatin-perforated whole-cell modes of the patch recording configuration. 2. In the perforated patch recording configuration, the application of glutamate (Glu), quisqualate (QA), aspartate (Asp) and N-methyl-D-aspartate (NMDA) induced a slow outward current superimposed on a fast ionotropic inward current, whereas alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) and kainate (KA) induced only an ionotropic inward current at a holding potential (VH) of -20 mV. A specific agonist of the mGlu receptor (mGluR), trans-1-aminocyclopentane-1,3-dicarboxylate (tACPD), induced an outward current in approximately 80% of the neurones tested. Asp- and NMDA-induced outward currents were antagonized by D-2-amino-5-phosphonopentanoate (D-AP5) whereas Glu-, QA- and tACPD-induced outward currents were not antagonized by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), 6,7-dinitroquinoxaline-2,3-dione (DNQX) and D-AP5, indicating that the mGlu response is an outward current component. 3. L-2-Amino-3-phosphonopropionate (L-AP3) and DL-2-amino-4-phosphonobutyrate (AP4) did not block the mGlu response. 4. The relative potencies of mGlu agonists were QA > Glu > tACPD. The threshold and EC50 values of metabotropic outward currents were 10-100 times lower than those of the ionotropic inward current (iGlu response). 5. The reversal potential of the mGlu response (EmGlu) was close to EK (K+ equilibrium potential), and it shifted 59.5 mV for a tenfold change in extracellular K+ concentration. 6. In Ca(2+)-free external solution, the mGlu response was elicited by an initial application of Glu, but subsequent applications failed to induce the response. There was also an increase in the intracellular free Ca2+ concentration ([Ca2+]i) during the application of Glu and QA but not of AMPA, indicating Ca2+ release from an intracellular Ca2+ store. 7

  2. Time courses of post-injury mitochondrial oxidative damage and respiratory dysfunction and neuronal cytoskeletal degradation in a rat model of focal traumatic brain injury.

    PubMed

    Hill, Rachel L; Singh, Indrapal N; Wang, Juan A; Hall, Edward D

    2017-03-23

    Traumatic brain injury (TBI) results in rapid reactive oxygen species (ROS) production and oxidative damage to essential brain cellular components leading to neuronal dysfunction and cell death. It is increasingly appreciated that a major player in TBI-induced oxidative damage is the reactive nitrogen species (RNS) peroxynitrite (PN) which is produced in large part in injured brain mitochondria. Once formed, PN decomposes into highly reactive free radicals that trigger membrane lipid peroxidation (LP) of polyunsaturated fatty acids (e.g. arachidonic acid) and protein nitration (3-nitrotyrosine, 3-NT) in mitochondria and other cellular membranes causing various functional impairments to mitochondrial oxidative phosphorylation and calcium (Ca(2+)) buffering capacity. The LP also results in the formation of neurotoxic reactive aldehyde byproducts including 4-hydroxynonenal (4-HNE) and propenal (acrolein) which exacerbates ROS/RNS production and oxidative protein damage in the injured brain. Ultimately, this results in intracellular Ca(2+) overload that activates proteolytic degradation of α-spectrin, a neuronal cytoskeletal protein. Therefore, the aim of this study was to establish the temporal evolution of mitochondrial dysfunction, oxidative damage and cytoskeletal degradation in the brain following a severe controlled cortical impact (CCI) TBI in young male adult rats. In mitochondria isolated from an 8 mm diameter cortical punch including the 5 mm wide impact site and their respiratory function studied ex vivo, we observed an initial decrease in complex I and II mitochondrial bioenergetics within 3 h (h). For complex I bioenergetics, this partially recovered by 12-16 h, whereas for complex II respiration the recovery was complete by 12 h. During the first 24 h, there was no evidence of an injury-induced increase in LP or protein nitration in mitochondrial or cellular homogenates. However, beginning at 24 h, there was a gradual secondary decline in complex

  3. Alpers progressive infantile neuronal poliodystrophy: an acute neonatal form with findings of the fetal akinesia syndrome.

    PubMed

    Frydman, M; Jager-Roman, E; de Vries, L; Stoltenburg-Didinger, G; Nussinovitch, M; Sirota, L

    1993-08-01

    We report on 8 patients from two families with Alpers syndrome. The onset in one family was prenatal and in the 4 patients who were examined, severe microcephaly, intrauterine growth retardation, and typical manifestations of fetal akinesia, including retrognathia, joint limitations, and chest deformity were found. The second family presented with an early infantile form. All the affected offspring had micrognathia and one had findings of fetal akinesia, comparable to those seen in the other family. Microcephaly was mild at birth and progressed with age. Refractory neonatal convulsions, swallowing difficulties, and pneumonia complicated the clinical course of patients in both families, and all the patients died before age 20 months. Results of comprehensive biochemical and metabolic studies in both families were normal and the diagnosis was supported by demonstration of extensive progressive brain atrophy on CT and typical histological findings. Patients without a detectable defect in energy metabolism and normal liver histology comprise a distinct subset of Alpers syndrome. Until the metabolic defect(s) is defined, we suggest naming the acute neonatal form of this subset of Alpers syndrome "type 1."

  4. A novel high channel-count system for acute multisite neuronal recordings.

    PubMed

    Hofmann, Ulrich G; Folkers, Andre; Mösch, Florian; Malina, Thomas; Menne, Kerstin M L; Biella, Gerardo; Fagerstedt, Patriq; De Schutter, Erik; Jensen, Winnie; Yoshida, Ken; Hoehl, Dirk; Thomas, Uwe; Kindlundh, Maria G; Norlin, Peter; de Curtis, Marco

    2006-08-01

    Multisite recording represents a suitable condition to study microphysiology and network interactions in the central nervous system and, therefore, to understand brain functions. Several different materials and array configurations have been proposed for the development of new probes utilized to record brain activity from experimental animal models. We describe new multisite silicon probes that broaden the currently available application base for neuroscientists. The array arrangement of the probes recording sites was extended to increase their spatial resolution. Probes were integrated with a newly developed electronic hardware and novel software for advanced real-time processing and analysis. The new system, based on 32- and 64-electrode silicon probes, proved very valuable to record field potentials and single unit activity from the olfactory-limbic cortex of the in vitro isolated guinea-pig brain preparation and to acutely record unit activity at multiple sites from the cerebellar cortex in vivo. The potential advantages of the new system in comparison to the currently available technology are discussed.

  5. Spores of Aspergillus versicolor isolated from indoor air of a moisture-damaged building provoke acute inflammation in mouse lungs.

    PubMed

    Jussila, Juha; Komulainen, Hannu; Kosma, Veli-Matti; Nevalainen, Aino; Pelkonen, Jukka; Hirvonen, Maija-Riitta

    2002-12-01

    Microbial growth in moisture-damaged buildings has been associated with respiratory health effects, and the spores of the mycotoxin producing fungus Aspergillus versicolor are frequently present in the indoor air. To characterize the potential of these spores to cause harmful respiratory effects, mice were exposed via intratracheal instillation to a single dose of the spores of A. versicolor (1 x 10(5), 1 x 10(6), 5 x 10(6), 1 x 10(7), or 1 x 10(8) spores), isolated from the indoor air of a moisture-damaged building. Inflammation and toxicity in lungs were evaluated 24 h later by assessment of biochemical markers and histopathology. The time course of the effects was investigated with the dose of 5 x 10(6) spores for up to 28 days. The exposure to the spores increased transiently proinflammatory cytokine levels (tumor necrosis factor [TNF] alpha and interleukin [IL]-6) in bronchoalveolar lavage fluid (BALF). The cytokine responses were dose and time dependent. The highest cytokine concentrations were measured at 6 h after the dose, and they returned to the control level by 3 days. Moreover, the spores of A. versicolor recruited inflammatory cells into airways: Neutrophils peaked transiently at 24 h, macrophages at 3 days, and lymphocytes at 7 days after the dosing. The inflammatory cell response did not completely disappear during the subsequent 28 days, though no histopathological changes were seen at that time point. The spores did not induce expression of inducible nitric oxide synthase in lavaged cells. Only the highest spore dose (1 x 10(8)) markedly increased serum IL-6, increased vascular leakage, and caused cytotoxicity (i.e., increased levels of albumin, total protein, lactate dehydrogenase [LDH], and hemoglobin in BALF) in the airways. In summary, the spores of A. versicolor caused acute inflammation in mouse lungs. This indicates that they have potential to provoke adverse health effects in the occupants of moisture-damaged buildings.

  6. The acute response of pericytes to muscle-damaging eccentric contraction and protein supplementation in human skeletal muscle.

    PubMed

    De Lisio, Michael; Farup, Jean; Sukiennik, Richard A; Clevenger, Nicole; Nallabelli, Julian; Nelson, Brett; Ryan, Kelly; Rahbek, Stine K; de Paoli, Frank; Vissing, Kristian; Boppart, Marni D

    2015-10-15

    Skeletal muscle pericytes increase in quantity following eccentric exercise (ECC) and contribute to myofiber repair and adaptation in mice. The purpose of the present investigation was to examine pericyte quantity in response to muscle-damaging ECC and protein supplementation in human skeletal muscle. Male subjects were divided into protein supplement (WHY; n = 12) or isocaloric placebo (CHO; n = 12) groups and completed ECC using an isokinetic dynamometer. Supplements were consumed 3 times/day throughout the experimental time course. Biopsies were collected prior to (PRE) and 3, 24, 48, and 168 h following ECC. Reflective of the damaging protocol, integrin subunits, including α7, β1A, and β1D, increased (3.8-fold, 3.6-fold and 3.9-fold, respectively, P < 0.01) 24 h post-ECC with no difference between supplements. Pericyte quantity did not change post-ECC. WHY resulted in a small, but significant, decrease in ALP(+) pericytes when expressed as a percentage of myonuclei (CHO 6.8 ± 0.3% vs. WHY 5.8 ± 0.3%, P < 0.05) or per myofiber (CHO 0.119 ± 0.01 vs. WHY 0.098 ± 0.01, P < 0.05). The quantity of myonuclei expressing serum response factor and the number of pericytes expressing serum response factor, did not differ as a function of time post-ECC or supplement. These data demonstrate that acute muscle-damaging ECC increases α7β1 integrin content in human muscle, yet pericyte quantity is largely unaltered. Future studies should focus on the capacity for ECC to influence pericyte function, specifically paracrine factor release as a mechanism toward pericyte contribution to repair and adaptation postexercise.

  7. Triptolide, a Chinese herbal extract, protects dopaminergic neurons from inflammation-mediated damage through inhibition of microglial activation.

    PubMed

    Li, Feng-Qiao; Lu, Xiu-Zhi; Liang, Xi-Bin; Zhou, Hui-Fang; Xue, Bing; Liu, Xian-Yu; Niu, Dong-Bin; Han, Ji-Sheng; Wang, Xiao-Min

    2004-03-01

    Mounting lines of evidence have suggested that brain inflammation participates in the pathogenesis of Parkinson's disease. Triptolide is one of the major active components of Chinese herb Tripterygium wilfordii Hook F, which possesses potent anti-inflammatory and immunosuppressive properties. We found that triptolide concentration-dependently attenuated the lipopolysaccharide (LPS)-induced decrease in [3H]dopamine uptake and loss of tyrosine hydroxylase-immunoreactive neurons in primary mesencephalic neuron/glia mixed culture. Triptolide also blocked LPS-induced activation of microglia and excessive production of TNFalpha and NO. Our data suggests that triptolide may protect dopaminergic neurons from LPS-induced injury and its efficiency in inhibiting microglia activation may underlie the mechanism.

  8. Changes in compressed neurons from dogs with acute and severe cauda equina constrictions following intrathecal injection of brain-derived neurotrophic factor-conjugated polymer nanoparticles☆

    PubMed Central

    Tan, Junming; Shi, Jiangang; Shi, Guodong; Liu, Yanling; Liu, Xiaohong; Wang, Chaoyang; Chen, Dechun; Xing, Shunming; Shen, Lianbing; Jia, Lianshun; Ye, Xiaojian; He, Hailong; Li, Jiashun

    2013-01-01

    This study established a dog model of acute multiple cauda equina constriction by experimental constriction injury (48 hours) of the lumbosacral central processes in dorsal root ganglia neurons. The repair effect of intrathecal injection of brain-derived neurotrophic factor with 15 mg encapsulated biodegradable poly(lactide-co-glycolide) nanoparticles on this injury was then analyzed. Dorsal root ganglion cells (L7) of all experimental dogs were analyzed using hematoxylin-eosin staining and immunohistochemistry at 1, 2 and 4 weeks following model induction. Intrathecal injection of brain-derived neurotrophic factor can relieve degeneration and inflammation, and elevate the expression of brain-derived neurotrophic factor in sensory neurons of compressed dorsal root ganglion. Simultaneously, intrathecal injection of brain-derived neurotrophic factor obviously improved neurological function in the dog model of acute multiple cauda equina constriction. Results verified that sustained intraspinal delivery of brain-derived neurotrophic factor encapsulated in biodegradable nanoparticles promoted the repair of histomorphology and function of neurons within the dorsal root ganglia in dogs with acute and severe cauda equina syndrome. PMID:25206593

  9. Time-Dependent Increases in Protease Activities for Neuronal Apoptosis in Spinal Cords of Lewis Rats During Development of Acute Experimental Autoimmune Encephalomyelitis

    PubMed Central

    Das, Arabinda; Guyton, M. Kelly; Matzelle, Denise D.; Ray, Swapan K.; Banik, Naren L.

    2008-01-01

    Multiple sclerosis (MS) is characterized by axonal demyelination and neurodegeneration, the latter having been inadequately explored in the MS animal model experimental autoimmune encephalomyelitis (EAE). The purpose of this study was to examine the time-dependent correlation between increased calpain and caspase activities and neurodegeneration in spinal cord tissues from Lewis rats with acute EAE. An increase in TUNEL-positive neurons and internucleosomal DNA fragmentation in EAE spinal cords suggested that neuronal death was a result of apoptosis on days 8–10 following induction of EAE. Increases in calpain expression in EAE correlated with activation of pro-apoptotic proteases, leading to apoptotic cell death beginning on day 8 of EAE, which occurred before the appearance of visible clinical symptoms. Increases in calcineurin expression and decreases in phospho-Bad (p-Bad) suggested Bad activation in apoptosis during acute EAE. Increases in the Bax:Bcl-2 ratio and activation of caspase-9 showed the involvement of mitochondria in apoptosis. Further, caspase-8 activation suggested induction of the death receptor–mediated pathway for apoptosis. Endoplasmic reticulum stress leading to caspase-3 activation was also observed, indicating that multiple apoptotic pathways were activated following EAE induction. In contrast, cell death was mostly a result of necrosis on the later day (day 11), when EAE entered a severe stage. From these findings, we conclude that increases in calpain and caspase activities play crucial roles in neuronal apoptosis during the development of acute EAE. PMID:18521931

  10. Chronic stress alters the dendritic morphology of callosal neurons and the acute glutamate stress response in the rat medial prefrontal cortex.

    PubMed

    Luczynski, Pauline; Moquin, Luc; Gratton, Alain

    2015-01-01

    We have previously reported that interhemispheric regulation of medial prefrontal cortex (PFC)-mediated stress responses is subserved by glutamate (GLU)- containing callosal neurons. Evidence of chronic stress-induced dendritic and spine atrophy among PFC pyramidal neurons led us to examine how chronic restraint stress (CRS) might alter the apical dendritic morphology of callosal neurons and the acute GLU stress responses in the left versus right PFC. Morphometric analyses of retrogradely labeled, dye-filled PFC callosal neurons revealed hemisphere-specific CRS-induced dendritic retraction; whereas significant dendritic atrophy occurred primarily within the distal arbor of left PFC neurons, it was observed within both the proximal and distal arbor of right PFC neurons. Overall, CRS also significantly reduced spine densities in both hemispheres with the greatest loss occurring among left PFC neurons, mostly at the distal extent of the arbor. While much of the overall decrease in dendritic spine density was accounted by the loss of thin spines, the density of mushroom-shaped spines, despite being fewer in number, was halved. Using microdialysis we found that, compared to controls, basal PFC GLU levels were significantly reduced in both hemispheres of CRS animals and that their GLU response to 30 min of tail-pinch stress was significantly prolonged in the left, but not the right PFC. Together, these findings show that a history of chronic stress alters the dendritic morphology and spine density of PFC callosal neurons and suggest a mechanism by which this might disrupt the interhemispheric regulation of PFC-mediated responses to subsequent stressors.

  11. Acute estradiol protects CA1 neurons from ischemia-induced apoptotic cell death via the PI3K/Akt pathway

    PubMed Central

    Jover-Mengual, Teresa; Miyawaki, Takahiro; Latuszek, Adrianna; Alborch, Enrique; Zukin, R. Suzanne; Etgen, Anne M.

    2010-01-01

    Global ischemia arising during cardiac arrest or cardiac surgery causes highly selective, delayed death of hippocampal CA1 neurons. Exogenous estradiol ameliorates global ischemia-induced neuronal death and cognitive impairment in male and female rodents. However, the molecular mechanisms by which a single acute injection of estradiol administered after the ischemic event intervenes in global ischemia-induced apoptotic cell death are unclear. Here we show that acute estradiol acts via the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling cascade to protect CA1 neurons in ovariectomized female rats. We demonstrate that global ischemia promotes early activation of glycogen synthase kinase-3β (GSK3β) and forkhead transcription factor of the O class (FOXO)3A, known Akt targets that are related to cell survival, and activation of caspase-3. Estradiol prevents ischemia-induced dephosphorylation and activation of GSK3β and FOXO3A, and the caspase death cascade. These findings support a model whereby estradiol acts by activation of PI3K/Akt signaling to promote neuronal survival in the face of global ischemia. PMID:20114038

  12. Study of DNA damage via the comet assay and base excision repair activities in rat brain neurons and astrocytes during aging.

    PubMed

    Swain, Umakanta; Subba Rao, Kalluri

    2011-08-01

    Earlier we have used biochemical approach to assess the number of single (SSBs) and double (DSBs) strand breaks in brain cellular DNA. However, a quick method to obtain a reliable measure of DNA damage in cells was in need for population studies. Therefore, single cell gel electrophoresis technique (popularly known as "comet" assay) has been standardized using the Trevigen protocol. DNA damage was assessed in isolated neurons and astrocytes from the cortex of young (7 days), adult (6 months) and old (2 years). Marked increase is seen in DNA damage in terms SSBs and DSBs in both types of cells by 6 months of age, which increased further by 2 years of age. The number of 8-oxoguanine DNA glycosylase (OGG1) and uracil DNA glycosylase (UDG) sensitive sites also increased in DNA with age with the simultaneous decrease in OGG1, UDG and AP endonuclease (APE1) activities. Thus the comet assay adapted to our lab conditions has proven to be useful for a quick assessment of DNA damage in a large number of samples that constitute our future studies.

  13. Pre- and post-treatments with escitalopram protect against experimental ischemic neuronal damage via regulation of BDNF expression and oxidative stress.

    PubMed

    Lee, Choong Hyun; Park, Joon Ha; Yoo, Ki-Yeon; Choi, Jung Hoon; Hwang, In Koo; Ryu, Pan Dong; Kim, Do-Hoon; Kwon, Young-Guen; Kim, Young-Myeong; Won, Moo-Ho

    2011-06-01

    Selective serotonin re-uptake inhibitors (SSRI) have been widely used in treatment of major depression because of their efficacy, safety, and tolerability. Escitalopram, an SSRI, is known to decrease oxidative stress in chronic stress animal models. In the present study, we examined the neuroprotective effects of pre- and post-treatments with 20 mg/kg and 30 mg/kg escitalopram in the gerbil hippocampal CA1 region (CA1) after transient cerebral ischemia. Pre-treatment with escitalopram protected against ischemia-induced neuronal death in the CA1 after ischemia/reperfusion (I/R). Post-treatment with 30 mg/kg, not 20 mg/kg, escitalopram had a neuroprotective effect against ischemic damage. In addition, 20 mg/kg pre- and 30 mg/kg post-treatments with escitalopram increased brain-derived neurotrophic factor (BDNF) protein levels in the ischemic CA1 compared to vehicle-treated ischemia animals. In addition, 20 mg/kg pre- and 30 mg/kg post-treatments with escitalopram reduced microglia activation and decreased 4-hydroxy-2-nonenal and Cu,Zn-superoxide dismutase immunoreactivity and their levels in the ischemic CA1 compared to vehicle-treated ischemia animals after transient cerebral ischemia. In conclusion, these results indicated that pre- and post-treatments with escitalopram can protect against ischemia-induced neuronal death in the CA1 induced by transient cerebral ischemic damage by increase of BDNF as well as decrease of microglia activation and oxidative stress.

  14. Ameliorating effects of traditional Chinese medicine preparation, Chinese materia medica and active compounds on ischemia/reperfusion-induced cerebral microcirculatory disturbances and neuron damage.

    PubMed

    Sun, Kai; Fan, Jingyu; Han, Jingyan

    2015-01-01

    Ischemic stroke and ischemia/reperfusion (I/R) injury induced by thrombolytic therapy are conditions with high mortality and serious long-term physical and cognitive disabilities. They have a major impact on global public health. These disorders are associated with multiple insults to the cerebral microcirculation, including reactive oxygen species (ROS) overproduction, leukocyte adhesion and infiltration, brain blood barrier (BBB) disruption, and capillary hypoperfusion, ultimately resulting in tissue edema, hemorrhage, brain injury and delayed neuron damage. Traditional Chinese medicine (TCM) has been used in China, Korea, Japan and other Asian countries for treatment of a wide range of diseases. In China, the usage of compound TCM preparation to treat cerebrovascular diseases dates back to the Han Dynasty. Even thousands of years earlier, the medical formulary recorded many classical prescriptions for treating cerebral I/R-related diseases. This review summarizes current information and underlying mechanisms regarding the ameliorating effects of compound TCM preparation, Chinese materia medica, and active components on I/R-induced cerebral microcirculatory disturbances, brain injury and neuron damage.

  15. Neuroprotection of Alpinia katsumadai Seed Extract against Neuronal Damage in the Ischemic Gerbil Hippocampus is Linked to Altered Brain-Derived Neurotrophic Factor.

    PubMed

    Li, Hua; Park, Joon Ha; Yan, Bingchun; Yoo, Ki-Yeon; Lee, Choong Hyun; Choi, Jung Hoon; Hwang, In Koo; Won, Moo-Ho

    2011-03-01

    The extract of Alpinia katsumadai, a member of the family Zingiberaceae, shows anti-inflammatory effects and antioxidant activity. We observed the neuroprotective effects of the extract from Alpinia katsumadai seed (EAKS) against ischemic damage in gerbils administered oral EAKS (25, and 50 mg/kg) once a day for 7 days before transient cerebral ischemia. In the 50 mg/kg EAKS-treated ischemia group, about 67% of neurons in the hippocampal CA1 region (CA1) survived after ischemia/reperfusion (I/R) based on cresyl violet staining. We observed that EAKS treatment significantly maintained brain-derived neurotrophic factor (BDNF) immunoreactivity in the ischemic CA1 region after I/R. In addition, protein levels of BDNF in the 50 mg/kg EAKS-treated ischemia group were much higher than those in the vehicle-treated ischemia group after I/R. These findings indicate that repeated supplementation of EAKS protects neurons from ischemic damage, such that BDNF is distinctively maintained in ischemic areas.

  16. Ameliorating effects of traditional Chinese medicine preparation, Chinese materia medica and active compounds on ischemia/reperfusion-induced cerebral microcirculatory disturbances and neuron damage

    PubMed Central

    Sun, Kai; Fan, Jingyu; Han, Jingyan

    2015-01-01

    Ischemic stroke and ischemia/reperfusion (I/R) injury induced by thrombolytic therapy are conditions with high mortality and serious long-term physical and cognitive disabilities. They have a major impact on global public health. These disorders are associated with multiple insults to the cerebral microcirculation, including reactive oxygen species (ROS) overproduction, leukocyte adhesion and infiltration, brain blood barrier (BBB) disruption, and capillary hypoperfusion, ultimately resulting in tissue edema, hemorrhage, brain injury and delayed neuron damage. Traditional Chinese medicine (TCM) has been used in China, Korea, Japan and other Asian countries for treatment of a wide range of diseases. In China, the usage of compound TCM preparation to treat cerebrovascular diseases dates back to the Han Dynasty. Even thousands of years earlier, the medical formulary recorded many classical prescriptions for treating cerebral I/R-related diseases. This review summarizes current information and underlying mechanisms regarding the ameliorating effects of compound TCM preparation, Chinese materia medica, and active components on I/R-induced cerebral microcirculatory disturbances, brain injury and neuron damage. PMID:26579420

  17. Absence of acute ocular damage in humans after prolonged exposure to intense RF EMF

    NASA Astrophysics Data System (ADS)

    Adibzadeh, F.; van Rhoon, G. C.; Verduijn, G. M.; Naus-Postema, N. C.; Paulides, M. M.

    2016-01-01

    The eye is considered to be a critical organ when determining safety standards for radio frequency (RF) radiation. Experimental data obtained using animals showed that RF heating of the eye, particularly over a specific threshold, can induce cataracts. During the treatment of cancer in the head and neck by hyperthermia, the eyes receive a considerable dose of RF radiation due to stray radiation from the prolonged (60 min) and intense exposure at 434 MHz of this region. In the current study, we verified the exposure guidelines for humans by determining the association between the electromagnetic and thermal dose in the eyes with the reported ocular effects. We performed a simulation study to retrospectively assess the specific absorption rate (SAR) and temperature increase in the eyes of 16 selected patients (encompassing a total of 74 treatment sessions) whose treatment involved high power delivery as well as a minimal distance between the tumor site and the eye. Our results show that the basic restrictions on the peak 10 g spatial-averaged SAR (10 W kg-1) and peak tissue temperature increase (1 °C) are exceeded by up to 10.4 and 4.6 times, on average, and by at least 6.2 and 1.8 times when considering the lower limit of the 95% confidence interval. Evaluation of the acute effects according to patients’ feedback (all patients), the common toxicity criteria scores (all patients) and an ophthalmology investigation (one patient with the highest exposure) revealed no indication of any serious acute ocular effect, even though the eyes were exposed to high electromagnetic fields, leading to a high thermal dose. We also found that, although there is a strong correlation (R 2  =  0.88) between the predicted induced SAR and temperature in the eye, there are large uncertainties regarding the temperature-SAR relationship. Given this large uncertainty (129%) compared with the uncertainty of 3D temperature simulations (61%), we recommend using temperature

  18. Absence of acute ocular damage in humans after prolonged exposure to intense RF EMF.

    PubMed

    Adibzadeh, F; van Rhoon, G C; Verduijn, G M; Naus-Postema, N C; Paulides, M M

    2016-01-21

    The eye is considered to be a critical organ when determining safety standards for radio frequency (RF) radiation. Experimental data obtained using animals showed that RF heating of the eye, particularly over a specific threshold, can induce cataracts. During the treatment of cancer in the head and neck by hyperthermia, the eyes receive a considerable dose of RF radiation due to stray radiation from the prolonged (60 min) and intense exposure at 434 MHz of this region. In the current study, we verified the exposure guidelines for humans by determining the association between the electromagnetic and thermal dose in the eyes with the reported ocular effects. We performed a simulation study to retrospectively assess the specific absorption rate (SAR) and temperature increase in the eyes of 16 selected patients (encompassing a total of 74 treatment sessions) whose treatment involved high power delivery as well as a minimal distance between the tumor site and the eye. Our results show that the basic restrictions on the peak 10 g spatial-averaged SAR (10 W kg(-1)) and peak tissue temperature increase (1 °C) are exceeded by up to 10.4 and 4.6 times, on average, and by at least 6.2 and 1.8 times when considering the lower limit of the 95% confidence interval. Evaluation of the acute effects according to patients' feedback (all patients), the common toxicity criteria scores (all patients) and an ophthalmology investigation (one patient with the highest exposure) revealed no indication of any serious acute ocular effect, even though the eyes were exposed to high electromagnetic fields, leading to a high thermal dose. We also found that, although there is a strong correlation (R (2) =  0.88) between the predicted induced SAR and temperature in the eye, there are large uncertainties regarding the temperature-SAR relationship. Given this large uncertainty (129%) compared with the uncertainty of 3D temperature simulations (61%), we recommend using temperature simulations as a

  19. MRI-based monitoring of inflammation and tissue damage in acute and chronic relapsing EAE.

    PubMed

    Rausch, M; Hiestand, P; Baumann, D; Cannet, C; Rudin, M

    2003-08-01

    Experimental autoimmune encephalomyelitis (EAE) is a commonly used animal model that in several respects mimics human multiple sclerosis (MS), and can be used to design or validate new strategies for treatment of this disease. In the present study, different MRI techniques (macrophage tracking based on labeling cells in vivo by ultrasmall particles of iron oxide (USPIO), blood-brain barrier (BBB) breakdown, and magnetization transfer imaging (MTI)), as well as immunohistological staining were used to study the burden of disease in Lewis rats immunized by guinea pig myelin. The resulting imaging data was compared with behavioral readouts. Animals were studied during the acute phase and the first relapse. Activated monocytes were detected during both episodes in the brain stem or cortex. These areas coincided in part with areas of BBB breakdown. Significant changes of the magnetization transfer ratios (MTRs) of up to 35% were observed in areas of USPIO accumulation. This suggests that infiltrating monocytes are the major source of demyelination in EAE, but monocyte infiltration and breakdown of the BBB are temporally or spatially independent inflammatory processes.

  20. Hepatoprotective Effect of Opuntia robusta and Opuntia streptacantha Fruits against Acetaminophen-Induced Acute Liver Damage

    PubMed Central

    González-Ponce, Herson Antonio; Martínez-Saldaña, María Consolación; Rincón-Sánchez, Ana Rosa; Sumaya-Martínez, María Teresa; Buist-Homan, Manon; Faber, Klaas Nico; Moshage, Han; Jaramillo-Juárez, Fernando

    2016-01-01

    Acetaminophen (APAP)-induced acute liver failure (ALF) is a serious health problem in developed countries. N-acetyl-l-cysteine (NAC), the current therapy for APAP-induced ALF, is not always effective, and liver transplantation is often needed. Opuntia spp. fruits are an important source of nutrients and contain high levels of bioactive compounds, including antioxidants. The aim of this study was to evaluate the hepatoprotective effect of Opuntia robusta and Opuntia streptacantha extracts against APAP-induced ALF. In addition, we analyzed the antioxidant activities of these extracts. Fruit extracts (800 mg/kg/day, orally) were given prophylactically to male Wistar rats before intoxication with APAP (500 mg/kg, intraperitoneally). Rat hepatocyte cultures were exposed to 20 mmol/L APAP, and necrosis was assessed by LDH leakage. Opuntia robusta had significantly higher levels of antioxidants than Opuntia streptacantha. Both extracts significantly attenuated APAP-induced injury markers AST, ALT and ALP and improved liver histology. The Opuntia extracts reversed APAP-induced depletion of liver GSH and glycogen stores. In cultured hepatocytes, Opuntia extracts significantly reduced leakage of LDH and cell necrosis, both prophylactically and therapeutically. Both extracts appeared to be superior to NAC when used therapeutically. We conclude that Opuntia extracts are hepatoprotective and can be used as a nutraceutical to prevent ALF. PMID:27782042

  1. Hepatoprotective Effect of Opuntia robusta and Opuntia streptacantha Fruits against Acetaminophen-Induced Acute Liver Damage.

    PubMed

    González-Ponce, Herson Antonio; Martínez-Saldaña, María Consolación; Rincón-Sánchez, Ana Rosa; Sumaya-Martínez, María Teresa; Buist-Homan, Manon; Faber, Klaas Nico; Moshage, Han; Jaramillo-Juárez, Fernando

    2016-10-04

    Acetaminophen (APAP)-induced acute liver failure (ALF) is a serious health problem in developed countries. N-acetyl-L-cysteine (NAC), the current therapy for APAP-induced ALF, is not always effective, and liver transplantation is often needed. Opuntia spp. fruits are an important source of nutrients and contain high levels of bioactive compounds, including antioxidants. The aim of this study was to evaluate the hepatoprotective effect of Opuntia robusta and Opuntia streptacantha extracts against APAP-induced ALF. In addition, we analyzed the antioxidant activities of these extracts. Fruit extracts (800mg/kg/day, orally) were given prophylactically to male Wistar rats before intoxication with APAP (500 mg/kg, intraperitoneally). Rat hepatocyte cultures were exposed to 20mmol/LAPAP, and necrosis was assessed by LDH leakage. Opuntia robusta had significantly higher levels of antioxidants than Opuntia streptacantha. Both extracts significantly attenuated APAP-induced injury markers AST, ALT and ALP and improved liver histology. The Opuntia extracts reversed APAP-induced depletion of liver GSH and glycogen stores. In cultured hepatocytes, Opuntia extracts significantly reduced leakage of LDH and cell necrosis, both prophylactically and therapeutically. Both extracts appeared to be superior to NAC when used therapeutically. We conclude that Opuntia extracts are hepatoprotective and can be used as a nutraceutical to prevent ALF.

  2. Kidney damage biomarkers detect acute kidney injury but only functional markers predict mortality after paraquat ingestion.

    PubMed

    Mohamed, Fahim; Buckley, Nicholas A; Jayamanne, Shaluka; Pickering, John W; Peake, Philip; Palangasinghe, Chathura; Wijerathna, Thilini; Ratnayake, Indira; Shihana, Fathima; Endre, Zoltan H

    2015-09-02

    Acute kidney injury (AKI) is common following paraquat ingestion. The diagnostic performance of injury biomarkers was investigated in serial blood and urine samples from patients from 5 Sri Lankan hospitals. Functional AKI was diagnosed using serum creatinine (sCr) or serum cystatin C (sCysC). The 95th centile in healthy subjects defined the urinary biomarker cutoffs for diagnosing structural AKI. 50 poisoned patients provided 2 or more specimens, 76% developed functional AKI [AKIN stage 1 (n=12), 2 (n=7) or 3 (n=19)]; 19/26 patients with AKIN stage 2/3 also had functional AKI by sCysC criteria (≥50% increase). Urinary cystatin C (uCysC), clusterin (uClu) and NGAL (uNGAL) increased within 24h of ingestion compared with NoAKI patients and healthy controls. Each biomarker demonstrated moderate diagnostic utility [AUC-ROC: uCysC 0.79, uNGAL 0.79, uClu 0.68] for diagnosis of functional AKI at 16h. Death occurred only in subjects with functional AKI. Structural biomarker-based definitions detected more AKI than did sCr or sCysC, but did not independently predict death. Renal injury biomarkers did not add clinical value to patients who died rapidly due to multi-organ failure. Use of injury biomarkers within 16-24h may guide early intervention for reno-protection in less severe paraquat poisoning.

  3. Long-Term Treatment with Losartan Attenuates Seizure Activity and Neuronal Damage Without Affecting Behavioral Changes in a Model of Co-morbid Hypertension and Epilepsy.

    PubMed

    Tchekalarova, Jana D; Ivanova, Natasha; Atanasova, Dimitrina; Pechlivanova, Daniela M; Lazarov, Nikolai; Kortenska, Lidia; Mitreva, Rumiana; Lozanov, Valentin; Stoynev, Alexander

    2016-08-01

    Over the last 10 years, accumulated experimental and clinical evidence has supported the idea that AT1 receptor subtype is involved in epilepsy. Recently, we have shown that the selective AT1 receptor antagonist losartan attenuates epileptogenesis and exerts neuroprotection in the CA1 area of the hippocampus in epileptic Wistar rats. This study aimed to verify the efficacy of long-term treatment with losartan (10 mg/kg) after kainate-induced status epilepticus (SE) on seizure activity, behavioral and biochemical changes, and neuronal damage in a model of co-morbid hypertension and epilepsy. Spontaneous seizures were video- and EEG-monitored in spontaneously hypertensive rats (SHRs) for a 16-week period after SE. The behavior was analyzed by open field, elevated plus maze, sugar preference test, and forced swim test. The levels of serotonin in the hippocampus and neuronal loss were estimated by HPLC and hematoxylin and eosin staining, respectively. The AT1 receptor antagonism delayed the onset of seizures and alleviated their frequency and duration during and after discontinuation of treatment. Losartan showed neuroprotection mostly in the CA3 area of the hippocampus and the septo-temporal hilus of the dentate gyrus in SHRs. However, the AT1 receptor antagonist did not exert a substantial influence on concomitant with epilepsy behavioral changes and decreased 5-HT levels in the hippocampus. Our results suggest that the antihypertensive therapy with an AT1 receptor blocker might be effective against seizure activity and neuronal damage in a co-morbid hypertension and epilepsy.

  4. Run-down of the GABAA response under experimental ischaemia in acutely dissociated CA1 pyramidal neurones of the rat.

    PubMed Central

    Harata, N; Wu, J; Ishibashi, H; Ono, K; Akaike, N

    1997-01-01

    1. The effect of experimental ischaemia on the response to gamma-aminobutyric acid (GABA) was assessed in acutely dissociated CA1 pyramidal neurones of rats, using the patch-clamp technique. 2. Rapid application of 3 x 10(-5) M GABA induced a bicuculline-sensitive inward Cl- current (IGABA) at a holding potential (Vh) of -44 mV. The peak amplitude of IGABA showed a time-dependent decrease (run-down) when it was recorded with the conventional whole-cell mode without internal ATP. The run-down was not observed when the intracellular ATP concentration ([ATP]i) was maintained by the nystatin-perforated recording with an intracellular Na+ concentration ([Na+]i) of 0 mM. 3. When [Na+]i was increased to more than 30 mM, the IGABA run-down was observed even with the nystatin-perforated recording. 4. The IGABA run-down observed at 60 mM [Na+]i with the nystatin method was further enhanced under experimental ischaemia without changes in the reversal potential of IGABA. The enhanced run-down was suppressed by application of the Na+,K(+)-ATPase inhibitors, ouabain and SPAI-1. 5. IGABA run-down during ischaemia was also accompanied by an outward holding current and a concomitant increase in intracellular free Ca2+ concentration ([Ca2+]i) in 48.5% of the neurones. The outward current was a Ca(2+)-activated K+ current, which was blocked by 3 x 10(-7) M charybdotoxin. 6. In the inside-out mode of the single-channel analysis, GABA activated three subconductance states with conductances of 33.4, 22.7 and 15.2 pS. Reduction of ATP concentration from 2 to 0 mM on the intracellular side suppressed the channel activities, while an increase in Ca2+ concentration from 0.7 x 10(-9) to 1.1 x 10(-6) M had no effect. 7. These results suggest that ischaemia induces the run-down of the postsynaptic GABA response at the GABAA receptor level, and that this run-down is triggered by a decrease in [ATP]i. Images Figure 3 Figure 4 Figure 5 Figure 6 PMID:9161985

  5. Metallothionein blocks oxidative DNA damage induced by acute inorganic arsenic exposure

    SciTech Connect

    Qu, Wei Waalkes, Michael P.

    2015-02-01

    We studied how protein metallothionein (MT) impacts arsenic-induced oxidative DNA damage (ODD) using cells that poorly express MT (MT-I/II double knockout embryonic cells; called MT-null cells) and wild-type (WT) MT competent cells. Arsenic (as NaAsO{sub 2}) was less cytolethal over 24 h in WT cells (LC{sub 50} = 11.0 ± 1.3 μM; mean ± SEM) than in MT-null cells (LC{sub 50} = 5.6 ± 1.2 μM). ODD was measured by the immuno-spin trapping method. Arsenic (1 or 5 μM; 24 h) induced much less ODD in WT cells (121% and 141% of control, respectively) than in MT-null cells (202% and 260%). In WT cells arsenic caused concentration-dependent increases in MT expression (transcript and protein), and in the metal-responsive transcription factor-1 (MTF-1), which is required to induce the MT gene. In contrast, basal MT levels were not detectable in MT-null cells and unaltered by arsenic exposure. Transfection of MT-I gene into the MT-null cells markedly reduced arsenic-induced ODD levels. The transport genes, Abcc1 and Abcc2 were increased by arsenic in WT cells but either showed no or very limited increases in MT-null cells. Arsenic caused increases in oxidant stress defense genes HO-1 and GSTα2 in both WT and MT-null cells, but to much higher levels in WT cells. WT cells appear more adept at activating metal transport systems and oxidant response genes, although the role of MT in these responses is unclear. Overall, MT protects against arsenic-induced ODD in MT competent cells by potential sequestration of scavenging oxidant radicals and/or arsenic. - Highlights: • Metallothionein blocks arsenic toxicity. • Metallothionein reduces arsenic-induced DNA damage. • Metallothionein may bind arsenic or radicals produced by arsenic.

  6. Acute effects of superimposed electromyostimulation during cycling on myokines and markers of muscle damage

    PubMed Central

    Wahl, P.; Hein, M.; Achtzehn, S.; Bloch, W.; Mester, J.

    2015-01-01

    Objectives: The purpose of the present study was to evaluate the effects of superimposed electromyostimulation (E) during cycling on myokines and markers of muscle damage, as E might be a useful tool to induce a high local stimulus to skeletal muscle during endurance training without performing high external workloads. Methods: 13 subjects participated in three experimental trials each lasting 60 min in a randomized order. 1) Cycling (C), 2) Cycling with superimposed E (C+E) and 3) E. Interleukin-6 (IL-6), brain-derived neurotrophic factor (BDNF), creatine kinase (CK) and myoglobin were determined before (pre) and 0’, 30’, 60’, 240’ and 24h after each intervention. Results: Only C+E caused significant increases in levels of CK and myoglobin. BDNF and IL-6 significantly increased after C and C+E, however increases for IL-6 were significantly higher after C+E compared to C. Conclusion: The present study showed that superimposed E during cycling might be a useful tool to induce a high local stimulus to skeletal muscle even when performing low to moderate external workloads. This effect might be due the activation of additional muscle fibers and mild eccentric work due to the concomitant activation of agonist and antagonist. However the higher load to skeletal muscle has to be taken into account. PMID:25730652

  7. Assessment of brainstem damage by the auditory brainstem response in acute severe head injury.

    PubMed Central

    Tsubokawa, T; Nishimoto, H; Yamamoto, T; Kitamura, M; Katayama, Y; Moriyasu, N

    1980-01-01

    In 64 cases suffering from severe head injury (Glasgow coma scale: less than seven- the auditory brainstem responses (FARs) recorded at the vertex, which are thought to be volumet conducted far-field potentials reflecting the sequential electrical activities of the auditory afferen) system in the brainstem, were recorded in the neurosurgical intensive care room immediately after admission. The alterations in the responses were compared with the types of primary injury, neurological signs., CT findings and outcome following treatment. Based on the results obtained, it is concluded that the FAR is a useful indicator for predicting the effects of treatment on brainstem damage in patients with severe head injury, and that it provides more reliable information about the function of the brainstem than the neurological signs or CT findings. Moreover, it also offers a diagnostic method for primary brainstem injury. Three cases or primary brainstem injury without lesions in the supratentorial region were diagnosed by means of combined CT and FAR recording. Images PMID:7441277

  8. Neuronal damage and functional deficits are ameliorated by inhibition of aquaporin and HIF1α after traumatic brain injury (TBI).

    PubMed

    Shenaq, Mohammed; Kassem, Hassan; Peng, Changya; Schafer, Steven; Ding, Jamie Y; Fredrickson, Vance; Guthikonda, Murali; Kreipke, Christian W; Rafols, José A; Ding, Yuchuan

    2012-12-15

    The present study, using a rodent model of closed-head diffuse traumatic brain injury (TBI), investigated the role of dysregulated aquaporins (AQP) 4 and 9, as well as hypoxia inducible factor -1α(HIF-1α) on brain edema formation, neuronal injury, and functional deficits. TBI was induced in adult (400-425 g), male Sprague-Dawley rats using a modified Marmarou's head impact-acceleration device (450 g weight dropped from 2m height). Animals in each treatment group were administered intravenous anti-AQP4 or -AQP9 antibodies or 2-Methoxyestradiol (2ME2, an inhibitor of HIF-1α) 30 min after injury. At 24h post-TBI, animals (n=6 each group) were sacrificed to examine the extent of brain edema by water content, as well as protein expression of AQP and HIF-1α by Western immune-blotting. At 48-hours post-TBI, neuronal injury (n=8 each group) was assessed by FluoroJade (FJ) histochemistry. Spatial learning and memory deficits were evaluated by radial arm maze (n=8 each group) up to 21 days post-TBI. Compared to non-injured controls, significant (p<0.05) increases in the expression of AQP4 and -9 were detected in the brains of injured animals. In addition, significant (p<0.05) brain edema after TBI was associated with increases (p <0.05) both in neuronal injury (FJ labeling) and neurobehavioral deficits. Selective inhibition of either AQP4 or -9, or HIF-1α significantly (p<0.05) decreased the expression of the proteins. In addition, inhibition of the AQPs and HIF-1α significantly (p<0.05) ameliorated brain edema, as well as the number of injured neurons in cortical layers II/III and V/VI, striatum and hippocampal regions CA1/CA3. Finally, compared to the non-treated TBI animals, AQP or HIF-1α inhibition significantly (p<0.01) improved neurobehavioral outcomes after TBI. Taken together, the present data supports a causal relation between HIF-AQP mediated cerebral edema, secondary neuronal injury, and tertiary behavioral deficits post-TBI. The data further suggests that

  9. Effects of glycerol on human skin damaged by acute sodium lauryl sulphate treatment.

    PubMed

    Atrux-Tallau, Nicolas; Romagny, Céline; Padois, Karine; Denis, Alain; Haftek, Marek; Falson, Françoise; Pirot, Fabrice; Maibach, Howard I

    2010-08-01

    Glycerol, widely used as humectant, is known to protect against irritants and to accelerate recovery of irritated skin. However, most studies were done with topical formulations (i.e. emulsions) containing glycerol in relatively high amounts, preventing drawing conclusions from direct effects. In this study, acute chemical irritations were performed on the forearm with application of a 10% sodium lauryl sulphate (SLS) aqueous solution under occlusion for 3 h. Then, glycerol aqueous solutions from 1 to 10% were applied under occlusion for 3 h. After elimination of moist excess consecutive to occlusive condition, in ambient air for 15 and 30 min, skin barrier function was investigated by dual measurement of skin hydration and transepidermal water loss (TEWL). Treatments with SLS solution under occlusion significantly increased TEWL and decreased skin hydration as assessed by capacitance measurements. The SLS irritant property was raised by the occlusion and the water barrier function as well as water content appeared impaired. Recovery with glycerol at low doses was remarkable through a mechanism that implies its hygroscopic properties and which is saturable. This precocious effect acts through skin rehydration by enhancing water-holding capacity of stratum corneum that would facilitate the late physiological repair of impaired skin barrier. Thus, glycerol appears to substitute for natural moisturizing factors that have been washed out by the detergent action of SLS, enhancing skin hydration but without restoring skin barrier function as depicted by TEWL values that remained high. Thus, irritant contact dermatitis treated with glycerol application compensate for skin dehydration, favouring physiological process to restore water barrier function of the impaired skin. Empirical use of glycerol added topical formulations onto detergent altered skin was substantiated in the present physicochemical approach.

  10. Is plasma urotensin II concentration an indicator of myocardial damage in patients with acute coronary syndrome?

    PubMed Central

    Babińska, Magdalena; Holecki, Michał; Prochaczek, Fryderyk; Owczarek, Aleksander; Kokocińska, Danuta; Więcek, Andrzej

    2012-01-01

    Introduction Urotensin II (UII) is a vasoactive peptide secreted by endothelial cells. Increased plasma UII concentration was observed in patients with heart failure, liver cirrhosis, diabetic nephropathy and renal insufficiency. In patients with myocardial infarction both increased and decreased plasma UII concentrations were demonstrated. The aim of this study was to analyze whether plasma UII concentration reflects the severity of acute coronary syndrome (ACS). Material and methods One hundred and forty-nine consecutive patients with ACS, without age limit, were enrolled in the study. In all patients plasma concentration of creatinine, creatine kinase isoenzyme MB (CK-MB), troponin C, N-terminal prohormone of brain natriuretic peptide (NT-pro BNP), and UII were assessed, and echocardiography was performed in order to assess the degree of left ventricular hypertrophy, ejection fraction (EF) and mass (LVM). Results In patients with the highest risk (TIMI 5-7) plasma UII concentration was significantly lower than in those with low risk (TIMI 1-2): 2.61±1.47 ng/ml vs. 3.60±2.20 ng/ml. Significantly lower plasma UII concentration was found in patients with increased concentration of troponin C (2.60±1.52 ng/ml vs. 3.41±2.09 ng/ml). There was a significant negative correlation between plasma UII concentration and TIMI score or concentration of troponin C, but not CK-MB. Borderline correlation between plasma UII and ejection fraction (R = 0.157; p=0.063) or NT-proBNP (R = − 0.156; p=0.058) was found. Conclusions Decreased plasma urotensin II concentration in patients with ACS could be associated with more severe injury of myocardium. PMID:22851999

  11. Effect of endurance training on seizure susceptibility, behavioral changes and neuronal damage after kainate-induced status epilepticus in spontaneously hypertensive rats.

    PubMed

    Tchekalarova, J; Shishmanova, M; Atanasova, D; Stefanova, M; Alova, L; Lazarov, N; Georgieva, K

    2015-11-02

    The therapeutic efficacy of regular physical exercises in an animal model of epilepsy and depression comorbidity has been confirmed previously. In the present study, we examined the effects of endurance training on susceptibility to kainate (KA)-induced status epilepticus (SE), behavioral changes and neuronal damage in spontaneously hypertensive rats (SHRs). Male SHRs were randomly divided into two groups. One group was exercised on a treadmill with submaximal loading for four weeks and the other group was sedentary. Immediately after the training period, SE was evoked in half of the sedentary and trained rats by KA, while the other half of the two groups received saline. Basal systolic (SP), diastolic (DP) and mean arterial pressure (MAP) of all rats were measured at the beginning and at the end of the training period. Anxiety, memory and depression-like behaviour were evaluated a month after SE. The release of 5-HT in the hippocampus was measured using a liquid scintillation method and neuronal damage was analyzed by hematoxylin and eosin staining. SP and MAP of exercised SHRs decreased in comparison with the initial values. The increased resistance of SHRs to KA-induced SE was accompanied by an elongated latent seizure-free period, improved object recognition memory and antidepressant effect after the training program. While the anticonvulsant and positive behavioral effects of endurance training were accompanied by an increase of 5-HT release in the hippocampus, it did not exert neuroprotective activity. Our results indicate that prior exercise is an effective means to attenuate KA-induced seizures and comorbid behavioral changes in a model of hypertension and epilepsy suggesting a potential influence of hippocampal 5-HT on a comorbid depression. However, this beneficial impact does not prevent the development of epilepsy and concomitant brain damage.

  12. Insulin-Like Growth Factor-I–Forkhead Box O Transcription Factor 3a Counteracts High Glucose/Tumor Necrosis Factor-α-Mediated Neuronal Damage: Implications for Human Immunodeficiency Virus Encephalitis

    PubMed Central

    Wilk, Anna; Urbanska, Katarzyna; Yang, Shuo; Wang, Jin Ying; Amini, Shohreh; Del Valle, Luis; Peruzzi, Francesca; Meggs, Leonard; Reiss, Krzysztof

    2012-01-01

    In HIV patients, antiretroviral medications trigger metabolic abnormalities, including insulin resistance. In addition, the inflammatory cytokine tumor necrosis factor-α (TNFα), which is elevated in human immunodeficiency virus encephalitis (HIVE), also induces insulin resistance and inflicts neuronal damage in vitro. In differentiated PC12 cells and rat cortical neurons, high glucose (HG; 25 mM) triggers reactive oxygen species (ROS) accumulation, contributing to the retraction of neuronal processes, with only a minimal involvement of neuronal apoptosis. In the presence of TNFα, HG-treated neurons undergo massive apoptosis. Because mammalian homolog of the Forkhead family of transcription factors, Forkhead box O transcription factor 3a (FOXO3a), controls ROS metabolism, we asked whether FOXO3a could affect the fate of differentiated neurons in the paradigm of HIVE. We observed FOXO3a nuclear translocation in HG-treated neuronal cultures, accompanied by partial loss of mitochondrial potential and gradual retraction of neuronal processes. Addition of TNFα to HG-treated neurons increased expression of the FOXO-dependent proapoptotic gene Bim, which resulted in extensive apoptotic death. Insulin-like growth factor-I (IGF-I) significantly lowered intracellular ROS, which was accompanied by IGF-I-mediated FOXO3a nuclear export and decrease in its transcriptional activity. The clinical relevance of these findings is supported by detection of nuclear FOXO3a in TUNEL-positive cortical neurons from HIVE, especially in brain areas characterized by elevated TNFα. PMID:21162126

  13. Mechanisms of action of DNA-damaging anticancer drugs in treatment of carcinomas: is acute apoptosis an "off-target" effect?

    PubMed

    Havelka, Aleksandra Mandic; Berndtsson, Maria; Olofsson, Maria Hägg; Shoshan, Maria C; Linder, Stig

    2007-10-01

    DNA damage induces apoptosis of cells of hematological origin. Apoptosis is also widely believed to be the major antiproliferative mechanism of DNA damaging anticancer drugs in other cell types, and a large number of laboratories have studied drug-induced acute apoptosis (within 24 hours) of carcinoma cells. It is, however, often overlooked that induction of apoptosis of carcinoma cells generally requires drug concentrations that are at least one order of magnitude higher than those required for loss of clonogenicity. This is true for different DNA damaging drugs such as cisplatin, doxorubicin and camptothecin. We here discuss apoptosis induction by DNA damaging agents using cisplatin as an example. Recent studies have shown that cisplatin induces caspase activation in enucleated cells (cytoplasts lacking a cell nucleus). Cisplatin-induced apoptosis in both cells and cytoplasts is associated with rapid induction of cellular reactive oxygen species and increases in [Ca(2+)](i). Cisplatin has also been reported to induce clustering of Fas/CD95 in the plasma membrane. Available data suggest that the primary responses to cisplatin-induced DNA damage are induction of long-term growth arrest ("premature cell senescence") and mitotic catastrophe, whereas acute apoptosis may be due to "off-target effects" not necessarily involving DNA damage.

  14. Global sensitivity analysis of a mathematical model of acute inflammation identifies nonlinear dependence of cumulative tissue damage on host interleukin-6 responses.

    PubMed

    Mathew, Shibin; Bartels, John; Banerjee, Ipsita; Vodovotz, Yoram

    2014-10-07

    The precise inflammatory role of the cytokine interleukin (IL)-6 and its utility as a biomarker or therapeutic target have been the source of much debate, presumably due to the complex pro- and anti-inflammatory effects of this cytokine. We previously developed a nonlinear ordinary differential equation (ODE) model to explain the dynamics of endotoxin (lipopolysaccharide; LPS)-induced acute inflammation and associated whole-animal damage/dysfunction (a proxy for the health of the organism), along with the inflammatory mediators tumor necrosis factor (TNF)-α, IL-6, IL-10, and nitric oxide (NO). The model was partially calibrated using data from endotoxemic C57Bl/6 mice. Herein, we investigated the sensitivity of the area under the damage curve (AUCD) to the 51 rate parameters of the ODE model for different levels of simulated LPS challenges using a global sensitivity approach called Random Sampling High Dimensional Model Representation (RS-HDMR). We explored sufficient parametric Monte Carlo samples to generate the variance-based Sobol' global sensitivity indices, and found that inflammatory damage was highly sensitive to the parameters affecting the activity of IL-6 during the different stages of acute inflammation. The AUCIL6 showed a bimodal distribution, with the lower peak representing healthy response and the higher peak representing sustained inflammation. Damage was minimal at low AUCIL6, giving rise to a healthy response. In contrast, intermediate levels of AUCIL6 resulted in high damage, and this was due to the insufficiency of damage recovery driven by anti-inflammatory responses from IL-10 and the activation of positive feedback sustained by IL-6. At high AUCIL6, damage recovery was interestingly restored in some population of simulated animals due to the NO-mediated anti-inflammatory responses. These observations suggest that the host's health status during acute inflammation depends in a nonlinear fashion on the magnitude of the inflammatory stimulus

  15. Long-term hematopoietic stem cell damage in a murine model of the hematopoietic syndrome of the acute radiation syndrome.

    PubMed

    Chua, Hui Lin; Plett, P Artur; Sampson, Carol H; Joshi, Mandar; Tabbey, Rebeka; Katz, Barry P; MacVittie, Thomas J; Orschell, Christie M

    2012-10-01

    Residual bone marrow damage (RBMD) persists for years following exposure to radiation and is believed to be due to decreased self-renewal potential of radiation-damaged hematopoietic stem cells (HSC). Current literature has examined primarily sublethal doses of radiation and time points within a few months of exposure. In this study, the authors examined RBMD in mice surviving lethal doses of total body ionizing irradiation (TBI) in a murine model of the Hematopoietic Syndrome of the Acute Radiation Syndrome (H-ARS). Survivors were analyzed at various time points up to 19 mo post-TBI for hematopoietic function. The competitive bone marrow (BM) repopulating potential of 150 purified c-Kit+ Sca-1+ lineage- CD150+ cells (KSLCD150+) remained severely deficient throughout the study compared to KSLCD150+ cells from non-TBI age-matched controls. The minimal engraftment from these TBI HSCs is predominantly myeloid, with minimal production of lymphocytes both in vitro and in vivo. All classes of blood cells as well as BM cellularity were significantly decreased in TBI mice, especially at later time points as mice aged. Primitive BM hematopoietic cells (KSLCD150+) displayed significantly increased cell cycling in TBI mice at all time points, which may be a physiological attempt to maintain HSC numbers in the post-irradiation state. Taken together, these data suggest that the increased cycling among primitive hematopoietic cells in survivors of lethal radiation may contribute to long-term HSC exhaustion and subsequent RBMD, exacerbated by the added insult of aging at later time points.

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

    PubMed

    Maeng, Lisa Y; Shors, Tracey J

    2013-01-01

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

  17. Association between neuroserpin and molecular markers of brain damage in patients with acute ischemic stroke

    PubMed Central

    2011-01-01

    Background Neuroserpin has shown neuroprotective effects in animal models of cerebral ischemia and has been associated with functional outcome after ischemic stroke. Our aim was to study whether neuroserpin serum levels could be associated to biomarkers of excitotoxicity, inflammation and blood brain barrier disruption. Methods We prospectively included 129 patients with ischemic stroke (58.1% male; mean age, 72.4 ± 9.6 years) not treated with tPA within 12 hours (h) of symptoms onset (mean time, 4.7 ± 2.1 h). Poor functional outcome at 3 months was considered as a modified Rankin scale score >2. Serum levels of neuroserpin, Interleukin 6 (IL-6), Intercellular adhesion molecule-1 (ICAM-1), active Matrix metalloproteinase 9 (MMP-9), and cellular fibronectin (cFn) (determined by ELISA) and glutamate (determined by HPLC) were measured on admission, 24 and 72 h. The main variable was considered the decrease of neuroserpin levels within the first 24 h. ROC analysis was used to select the best predictive value for neuroserpin to predict poor functional outcome due to a lack of linearity. Results The decrease of neuroserpin levels within the first 24 h was negatively correlated with serum levels at 24 hours of glutamate (r = -0.642), IL-6 (r = -0.678), ICAM-1 (r = -0.345), MMP-9 (r = -0.554) and cFn (r = -0.703) (all P < 0.0001). In the multivariate analysis, serum levels of glutamate (OR, 1.04; CI95%, 1.01-1.06, p = 0.001); IL-6 (OR, 1.4; CI95%, 1.1-1.7, p = 0.001); and cFn (OR, 1.3; CI95%, 1.1-1.6, p = 0.002) were independently associated with a decrease of neuroserpin levels <70 ng/mL at 24 h after adjusting for confounding factors. Conclusions These findings suggest that neuroprotective properties of neuroserpin may be related to the inhibition of excitotoxicity, inflammation, as well as blood brain barrier disruption that occur after acute ischemic stroke. PMID:21569344

  18. Recovery of hypothalamic tuberoinfundibular dopamine neurons from acute toxicant exposure is dependent upon protein synthesis and associated with an increase in parkin and ubiquitin carboxy-terminal hydrolase-L1 expression.

    PubMed

    Benskey, Matthew; Behrouz, Bahareh; Sunryd, Johan; Pappas, Samuel S; Baek, Seung-Hoon; Huebner, Marianne; Lookingland, Keith J; Goudreau, John L

    2012-06-01

    Hypothalamic tuberoinfundibular dopamine (TIDA) neurons remain unaffected in Parkinson disease (PD) while there is significant degeneration of midbrain nigrostriatal dopamine (NSDA) neurons. A similar pattern of susceptibility is observed in acute and chronic 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse and rotenone rat models of degeneration. It is not known if the resistance of TIDA neurons is a constitutive or induced cell-autonomous phenotype for this unique subset of DA neurons. In the present study, treatment with a single injection of MPTP (20 mg/kg; s.c.) was employed to examine the response of TIDA versus NSDA neurons to acute injury. An acute single dose of MPTP caused an initial loss of DA from axon terminals of both TIDA and NSDA neurons, with recovery occurring solely in TIDA neurons by 16 h post-treatment. Initial loss of DA from axon terminals was dependent on a functional dopamine transporter (DAT) in NSDA neurons but DAT-independent in TIDA neurons. The active metabolite of MPTP, 1-methyl, 4-phenylpyradinium (MPP+), reached higher concentration and was eliminated slower in TIDA compared to NSDA neurons, which indicates that impaired toxicant bioactivation or distribution is an unlikely explanation for the observed resistance of TIDA neurons to MPTP exposure. Inhibition of protein synthesis prevented TIDA neuron recovery, suggesting that the ability to recover from injury was dependent on an induced, rather than a constitutive cellular mechanism. Further, there were no changes in total tyrosine hydroxylase (TH) expression following MPTP, indicating that up-regulation of the rate-limiting enzyme in DA synthesis does not account for TIDA neuronal recovery. Differential candidate gene expression analysis revealed a time-dependent increase in parkin and ubiquitin carboxyl-terminal hydrolase-L1 (UCH-L1) expression (mRNA and protein) in TIDA neurons during recovery from injury. Parkin expression was also found to increase with incremental

  19. [Neuronal ageing].

    PubMed

    Piechota, Małgorzata; Sunderland, Piotr

    2014-01-01

    Ageing leads to irreversible alterations in the nervous system, which to various extent impair its functions such as capacity to learn and memory. In old neurons and brain, similarly to what may take place in other cells, there is increased oxidative stress, disturbed energetic homeostasis and metabolism, accumulation of damage in proteins and nucleic acids. Characteristic of old neurons are alterations in plasticity, synaptic transmission, sensitivity to neurotrophic factors and cytoskeletal changes. Some markers of senescence, whose one of them is SA-beta-galactosidase were used to show the process of neuronal ageing both in vitro, and in vivo. Some research suggest that, despite the fact that neurons are postmitotic cells, it is cell cycle proteins which play a certain role in their biology, e.g. differentiation. However, their role in neuronal ageing is not known or explained. Ageing is the serious factor of development of neurodegenerative diseases among others Alzheimer disease.

  20. Flaxseed Mitigates Acute Oxidative Lung Damage in a Mouse Model of Repeated Radiation and Hyperoxia Exposure Associated with Space Exploration

    PubMed Central

    Pietrofesa, Ralph A.; Solomides, Charalambos C.; Christofidou-Solomidou, Melpo

    2015-01-01

    Background Spaceflight missions may require crewmembers to conduct extravehicular activities (EVA). Pre-breathe protocols in preparation for an EVA entail 100% hyperoxia exposure that may last for a few hours and be repeated 2-3 times weekly. Each EVA is associated with additional challenges such as low levels of total body cosmic/galactic radiation exposure that may present a threat to crewmember health. We have developed a mouse model of total body radiation and hyperoxia exposure and identified acute damage of lung tissues. In the current study we evaluated the usefulness of dietary flaxseed (FS) as a countermeasure agent for such double-hit exposures. Methods We evaluated lung tissue changes 2 weeks post-initiation of exposure challenges. Mouse cohorts (n=5/group) were pre-fed diets containing either 0% FS or 10% FS for 3 weeks and exposed to: a) normoxia (Untreated); b) >95% O2 (O2); c) 0.25Gy single fraction gamma radiation (IR); or d) a combination of O2 and IR (O2+IR) 3 times per week for 2 consecutive weeks, where 8-hour hyperoxia treatments were spanned by normoxic intervals. Results At 2 weeks post challenge, while control-diet fed mice developed significant lung injury and inflammation across all challenges, FS protected lung tissues by decreasing bronchoalveolar lavage fluid (BALF) neutrophils (p<0.003) and protein levels, oxidative tissue damage, as determined by levels of malondialdehyde (MDA) (p<0.008) and nitrosative stress as determined by nitrite levels. Lung hydroxyproline levels, a measure of lung fibrosis, were significantly elevated in mice fed 0% FS (p<0.01) and exposed to hyperoxia/radiation or the combination treatment, but not in FS-fed mice. FS also decreased levels of a pro-inflammatory, pro-fibrogenic cytokine (TGF-β1) gene expression levels in lung. Conclusion Flaxseed mitigated adverse effects in lung of repeat exposures to radiation/hyperoxia. This data will provide useful information in the design of countermeasures to early

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

    PubMed Central

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

    2016-01-01

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

  2. Acute morphine induces matrix metalloproteinase-9 up-regulation in primary sensory neurons to mask opioid-induced analgesia in mice

    PubMed Central

    2012-01-01

    Background Despite decades of intense research efforts, actions of acute opioids are not fully understood. Increasing evidence suggests that in addition to well-documented antinociceptive effects opioids also produce paradoxical hyperalgesic and excitatory effects on neurons. However, most studies focus on the pronociceptive actions of chronic opioid exposure. Matrix metalloproteinase 9 (MMP-9) plays an important role in neuroinflammation and neuropathic pain development. We examined MMP-9 expression and localization in dorsal root ganglia (DRGs) after acute morphine treatment and, furthermore, the role of MMP-9 in modulating acute morphine-induced analgesia and hyperalgesia in mice. Results Subcutaneous morphine induced a marked up-regulation of MMP-9 protein in DRGs but not spinal cords. Morphine also increased MMP-9 activity and mRNA expression in DRGs. MMP-9 up-regulation peaked at 2 h but returned to the baseline after 24 h. In DRG tissue sections, MMP-9 is expressed in small and medium-sized neurons that co-express mu opioid receptors (MOR). In DRG cultures, MOR agonists morphine, DAMGO, and remifentanil each increased MMP-9 expression in neurons, whereas the opioid receptor antagonist naloxone and the MOR-selective antagonist D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH2 (CTAP) suppressed morphine-induced MMP-9 expression. Notably, subcutaneous morphine-induced analgesia was enhanced and prolonged in Mmp9 knockout mice and also potentiated in wild-type mice receiving intrathecal injection of MMP-9 inhibitors. Consistently, intrathecal injection of specific siRNA targeting MMP-9 reduced MMP-9 expression in DRGs and enhanced and prolonged morphine analgesia. Subcutaneous morphine also produced heat hyperalgesia at 24 h, but this opioid-induced hyperalgesia was not enhanced after MMP-9 deletion or inhibition. Conclusions Transient MMP-9 up-regulation in DRG neurons can mask opioid analgesia, without modulating opioid-induced hyperalgesia. Distinct molecular

  3. Lycopene treatment prevents hematological, reproductive and histopathological damage induced by acute zearalenone administration in male Swiss mice.

    PubMed

    Boeira, Silvana Peterini; Filho, Carlos Borges; Del'Fabbro, Lucian; Roman, Silvane Souza; Royes, Luiz Fernando Freire; Fighera, Michele Rechia; Jessé, Cristiano Ricardo; Oliveira, Mauro Schneider; Furian, Ana Flávia

    2014-07-01

    Zearalenone (ZEA) is a mycotoxin commonly found as a contaminant in cereals. ZEA toxicity targets mainly the reproductive system, and oxidative stress plays an etiological role in its toxic effects. Therefore, the present study aimed to investigate the effect of lycopene, a potent carotenoid antioxidant, on markers of oxidative stress in liver, kidney and testes, and on reproductive, hematological and histopathological parameters after ZEA administration. Adult Swiss albino male mice received lycopene (20mg/kg, p.o.) for ten days before a single oral administration of ZEA (40mg/kg, p.o.), and 48h thereafter tissues (liver, kidney, testes and blood) were collected for biochemical, hematological and histological analyses. Lycopene prevented ZEA-induced changes in hematological parameters (increased number of leukocytes, segmented neutrophils, sticks, eosinophils and monocytes and decreased number of red blood cells (RBC), number of lymphocytes and platelets). Moreover, lycopene prevented the reduction in the number and motility of spermatozoa and the testicular tissue damage induced by ZEA. In addition, lycopene prevented the decrease in glutathione-S-transferase activity in kidney and testes and increased glutathione-S-transferase activity per se in the liver, kidneys and testes as well as superoxide dismutase activity in the liver. In summary, lycopene was able to prevent ZEA-induced acute toxic effects in male mice, suggesting that this antioxidant carotenoid may represent a promising prophylactic strategy against ZEA toxicity.

  4. α2δ-1 Gene Deletion Affects Somatosensory Neuron Function and Delays Mechanical Hypersensitivity in Response to Peripheral Nerve Damage

    PubMed Central

    Patel, Ryan; Bauer, Claudia S.; Nieto-Rostro, Manuela; Margas, Wojciech; Ferron, Laurent; Chaggar, Kanchan; Crews, Kasumi; Ramirez, Juan D.; Bennett, David L. H.; Schwartz, Arnold; Dickenson, Anthony H.

    2013-01-01

    The α2δ-1 subunit of voltage-gated calcium channels is upregulated after sensory nerve injury and is also the therapeutic target of gabapentinoid drugs. It is therefore likely to play a key role in the development of neuropathic pain. In this study, we have examined mice in which α2δ-1 gene expression is disrupted, to determine whether α2δ-1 is involved in various modalities of nociception, and for the development of behavioral hypersensitivity after partial sciatic nerve ligation (PSNL). We find that naive α2δ-1−/− mice show a marked behavioral deficit in mechanical and cold sensitivity, but no change in thermal nociception threshold. The lower mechanical sensitivity is mirrored by a reduced in vivo electrophysiological response of dorsal horn wide dynamic range neurons. The CaV2.2 level is reduced in brain and spinal cord synaptosomes from α2δ-1−/− mice, and α2δ-1−/− DRG neurons exhibit lower calcium channel current density. Furthermore, a significantly smaller number of DRG neurons respond to the TRPM8 agonist menthol. After PSNL, α2δ-1−/− mice show delayed mechanical hypersensitivity, which only develops at 11 d after surgery, whereas in wild-type littermates it is maximal at the earliest time point measured (3 d). There is no compensatory upregulation of α2δ-2 or α2δ-3 after PSNL in α2δ-1−/− mice, and other transcripts, including neuropeptide Y and activating transcription factor-3, are upregulated normally. Furthermore, the ability of pregabalin to alleviate mechanical hypersensitivity is lost in PSNL α2δ-1−/− mice. Thus, α2δ-1 is essential for rapid development of mechanical hypersensitivity in a nerve injury model of neuropathic pain. PMID:24133248

  5. α2δ-1 gene deletion affects somatosensory neuron function and delays mechanical hypersensitivity in response to peripheral nerve damage.

    PubMed

    Patel, Ryan; Bauer, Claudia S; Nieto-Rostro, Manuela; Margas, Wojciech; Ferron, Laurent; Chaggar, Kanchan; Crews, Kasumi; Ramirez, Juan D; Bennett, David L H; Schwartz, Arnold; Dickenson, Anthony H; Dolphin, Annette C

    2013-10-16

    The α2δ-1 subunit of voltage-gated calcium channels is upregulated after sensory nerve injury and is also the therapeutic target of gabapentinoid drugs. It is therefore likely to play a key role in the development of neuropathic pain. In this study, we have examined mice in which α2δ-1 gene expression is disrupted, to determine whether α2δ-1 is involved in various modalities of nociception, and for the development of behavioral hypersensitivity after partial sciatic nerve ligation (PSNL). We find that naive α2δ-1(-/-) mice show a marked behavioral deficit in mechanical and cold sensitivity, but no change in thermal nociception threshold. The lower mechanical sensitivity is mirrored by a reduced in vivo electrophysiological response of dorsal horn wide dynamic range neurons. The CaV2.2 level is reduced in brain and spinal cord synaptosomes from α2δ-1(-/-) mice, and α2δ-1(-/-) DRG neurons exhibit lower calcium channel current density. Furthermore, a significantly smaller number of DRG neurons respond to the TRPM8 agonist menthol. After PSNL, α2δ-1(-/-) mice show delayed mechanical hypersensitivity, which only develops at 11 d after surgery, whereas in wild-type littermates it is maximal at the earliest time point measured (3 d). There is no compensatory upregulation of α2δ-2 or α2δ-3 after PSNL in α2δ-1(-/-) mice, and other transcripts, including neuropeptide Y and activating transcription factor-3, are upregulated normally. Furthermore, the ability of pregabalin to alleviate mechanical hypersensitivity is lost in PSNL α2δ-1(-/-) mice. Thus, α2δ-1 is essential for rapid development of mechanical hypersensitivity in a nerve injury model of neuropathic pain.

  6. Rho kinase inhibition following traumatic brain injury in mice promotes functional improvement and acute neuron survival but has little effect on neurogenesis, glial responses or neuroinflammation.

    PubMed

    Bye, Nicole; Christie, Kimberly J; Turbic, Alisa; Basrai, Harleen S; Turnley, Ann M

    2016-05-01

    Inhibition of the Rho/Rho kinase pathway has been shown to be beneficial in a variety of neural injuries and diseases. In this manuscript we investigate the role of Rho kinase inhibition in recovery from traumatic brain injury using a controlled cortical impact model in mice. Mice subjected to a moderately severe TBI were treated for 1 or 4 weeks with the Rho kinase inhibitor Y27632, and functional outcomes and neuronal and glial cell responses were analysed at 1, 7 and 35 days post-injury. We hypothesised that Y27632-treated mice would show functional improvement, with augmented recruitment of neuroblasts from the SVZ and enhanced survival of newborn neurons in the pericontusional cortex, with protection against neuronal degeneration, neuroinflammation and modulation of astrocyte reactivity and blood-brain-barrier permeability. While Rho kinase inhibition enhanced recovery of motor function after trauma, there were no substantial increases in the recruitment of DCX(+) neuroblasts or the number of BrdU(+) or EdU(+) labelled newborn neurons in the pericontusional cortex of Y27632-treated mice. Inhibition of Rho kinase significantly reduced the number of degenerating cortical neurons at 1day post-injury compared to saline controls but had no longer term effect on neuronal degeneration, with only modest effects on astrocytic reactivity and macrophage/microglial responses. Overall, this study showed that Rho kinase contributes to acute neurodegenerative processes in the injured cortex but does not play a significant role in SVZ neural precursor cell-derived adult neurogenesis, glial responses or blood-brain barrier permeability following a moderately severe brain injury.

  7. Preventing neuronal damage and inflammation in vivo during cortical microelectrode implantation through the use of Poloxamer P-188

    NASA Astrophysics Data System (ADS)

    Misra, A.; Kondaveeti, P.; Nissanov, J.; Barbee, K.; Shewokis, P.; Rioux, L.; Moxon, K. A.

    2013-02-01

    Objective. The aim of this study was to test the efficacy of Poloxamer P188 to reduce cell death and immune response associated with mechanical trauma to cells during implantation of a chronic recording electrode. Approach. Ceramic multi-site recording electrodes were implanted bilaterally into 15 adult male Long-Evans rats. One of each pair was randomly assigned to receive a coating of Poloxamer while the other was treated with saline. The extent of neuron loss, and glial cell recruitment were characterized at 2, 4 and 6 weeks post-implantation by stereologic analysis. Main results. At 2 and 4 weeks post-implantation, Poloxamer-coated implants showed significantly fewer glial cells and more neurons in the peri-electrode space than controls; however, this significance was lost by 6 weeks. Significance. These findings are the first to suggest that Poloxamer has neuroprotective effects in vivo; however, at a fixed loading dose, these effects are limited to approximately 1 month post-implantation.

  8. Optical electrocorticogram (OECoG) using wide-field calcium imaging reveals the divergence of neuronal and glial activity during acute rodent seizures.

    PubMed

    Daniel, Andy G S; Laffont, Philippe; Zhao, Mingrui; Ma, Hongtao; Schwartz, Theodore H

    2015-08-01

    The role of glia in epilepsy has been widely debated. Using in vivo bulk loading of calcium dyes, we imaged neuronal and glial activity in an acute pharmacologic rodent model of neocortical seizures. Optical calcium-based ECoG maps revealed that neuronal waves propagated rapidly and remained mostly confined to the seizure focus. Glial waves were triggered by ictal onset but propagated slowly in a stereotypical fashion far beyond the seizure focus. Although related at their onset, the divergence of these two phenomena during seizure evolution calls into question their interdependence and the criticality of the role of glia in seizure onset and neurovascular coupling. This article is part of a Special Issue entitled "Status Epilepticus".

  9. Attenuation of acute and chronic effects of morphine by the imidazoline receptor ligand 2-(2-benzofuranyl)-2-imidazoline in rat locus coeruleus neurons

    PubMed Central

    Ruiz-Durántez, Eduardo; Torrecilla, María; Pineda, Joseba; Ugedo, Luisa

    2003-01-01

    The aim of this study was to determine if 2-(2-benzofuranyl)-2-imidazoline (2-BFI) interacts with the opioid system in the rat locus coeruleus, using single-unit extracellular recordings. In morphine-dependent rats, acute administration of the selective imidazoline receptor ligands 2-BFI (10 and 40 mg kg−1, i.p. and 100 μg, i.c.v.) or valldemossine (10 mg kg−1, i.p.) did not modify the naloxone-induced hyperactivity of locus coeruleus neurons compared with that observed in the morphine-dependent control group. After chronic administration of 2-BFI (10 mg kg−1, i.p., three times daily, for 5 days) and morphine, naloxone-induced hyperactivity and tolerance to morphine were attenuated. This effect was not observed when a lower dose of 2-BFI (1 mg kg−1, i.p.) or valldemossine (10 mg kg−1, i.p.) were used. Acute administration of 2-BFI (10 and 40 mg kg−1, i.p. and 100 μg, i.c.v.) but not valldemossine (40 mg kg−1, i.p.) diminished the potency of morphine to inhibit locus coeruleus neuron activity in vivo (ED50 values increased by 2.3, 2.9; and 3.1 fold respectively). Similarly, the potency of Met5-enkephalin to inhibit locus coeruleus neurons was decreased when 2-BFI (100 μM) was applied to rat brain slices (EC50 increased by 5.6; P<0.05). The present data demonstrate that there is an interaction between 2-BFI and the opioid system in the locus coeruleus. This interaction leads to an attenuation of both the hyperactivity of locus coeruleus neurons during opiate withdrawal and the development of tolerance to morphine when 2-BFI is chronically administered. These results suggest that imidazoline drugs may prove to be useful agents for the management of opioid dependence and tolerance. PMID:12569074

  10. Damage to pancreatic acinar cells and preservation of islets of Langerhans in a rat model of acute pancreatitis induced by Karwinskia humboldtiana (buckthorn).

    PubMed

    Carcano-Diaz, Katya; Garcia-Garcia, Aracely; Segoviano-Ramirez, Juan Carlos; Rodriguez-Rocha, Humberto; Loera-Arias, Maria de Jesus; Garcia-Juarez, Jaime

    2016-09-01

    Karwinskia humboldtiana (Kh) is a poisonous plant that grows in some regions of the American continent. Consuming large amounts of Kh fruit results in acute intoxication leading to respiratory failure, culminating in death within days. There is evidence of histological damage to the lungs, liver, and kidneys following accidental and experimental Kh intoxication. To date, the microscopic effect of Kh consumption on the pancreas has not been described. We examined the early effects of Kh fruit on pancreatic tissue at different stages of acute intoxication in the Wistar rat. We found progressive damage confined to the exocrine pancreas, starting with a reduction in the number of zymogen granules, loss of acinar architecture, the presence of autophagy-like vesicles, apoptosis and inflammatory infiltrate. The pancreatic pathology culminated in damaged acini characterized by necrosis and edema, with a complete loss of lobular architecture. Interestingly, the morphology of the islets of Langerhans was conserved throughout our evaluations. Taken together, our results indicate the damage induced by a high dose of Kh fruit in the Wistar rat is consistent with an early acute necrotizing pancreatitis that exclusively affects the exocrine pancreas. Therefore, this system might be useful as an animal model to study the treatment of pancreatic diseases. More importantly, as the islets of Langerhans were preserved, the active compounds of Kh fruit could be utilized for the treatment of acinar pancreatic cancer. Further studies might provide insight into the severity of acute Kh intoxication in humans and influence the design of treatments for pancreatic diseases and acinar pancreatic cancer.

  11. Effects of Cannabidiol and Hypothermia on Short-Term Brain Damage in New-Born Piglets after Acute Hypoxia-Ischemia.

    PubMed

    Lafuente, Hector; Pazos, Maria R; Alvarez, Antonia; Mohammed, Nagat; Santos, Martín; Arizti, Maialen; Alvarez, Francisco J; Martinez-Orgado, Jose A

    2016-01-01

    Hypothermia is a standard treatment for neonatal encephalopathy, but nearly 50% of treated infants have adverse outcomes. Pharmacological therapies can act through complementary mechanisms with hypothermia improving neuroprotection. Cannabidiol could be a good candidate. Our aim was to test whether immediate treatment with cannabidiol and hypothermia act through complementary brain pathways in hypoxic-ischemic newborn piglets. Hypoxic-ischemic animals were randomly divided into four groups receiving 30 min after the insult: (1) normothermia and vehicle administration; (2) normothermia and cannabidiol administration; (3) hypothermia and vehicle administration; and (4) hypothermia and cannabidiol administration. Six hours after treatment, brains were processed to quantify the number of damaged neurons by Nissl staining. Proton nuclear magnetic resonance spectra were obtained and analyzed for lactate, N-acetyl-aspartate and glutamate. Metabolite ratios were calculated to assess neuronal damage (lactate/N-acetyl-aspartate) and excitotoxicity (glutamate/Nacetyl-aspartate). Western blot studies were performed to quantify protein nitrosylation (oxidative stress), content of caspase-3 (apoptosis) and TNFα (inflammation). Individually, the hypothermia and the cannabidiol treatments reduced the glutamate/Nacetyl-aspartate ratio, as well as TNFα and oxidized protein levels in newborn piglets subjected to hypoxic-ischemic insult. Also, both therapies reduced the number of necrotic neurons and prevented an increase in lactate/N-acetyl-aspartate ratio. The combined effect of hypothermia and cannabidiol on excitotoxicity, inflammation and oxidative stress, and on cell damage, was greater than either hypothermia or cannabidiol alone. The present study demonstrated that cannabidiol and hypothermia act complementarily and show additive effects on the main factors leading to hypoxic-ischemic brain damage if applied shortly after the insult.

  12. Effects of Cannabidiol and Hypothermia on Short-Term Brain Damage in New-Born Piglets after Acute Hypoxia-Ischemia

    PubMed Central

    Lafuente, Hector; Pazos, Maria R.; Alvarez, Antonia; Mohammed, Nagat; Santos, Martín; Arizti, Maialen; Alvarez, Francisco J.; Martinez-Orgado, Jose A.

    2016-01-01

    Hypothermia is a standard treatment for neonatal encephalopathy, but nearly 50% of treated infants have adverse outcomes. Pharmacological therapies can act through complementary mechanisms with hypothermia improving neuroprotection. Cannabidiol could be a good candidate. Our aim was to test whether immediate treatment with cannabidiol and hypothermia act through complementary brain pathways in hypoxic-ischemic newborn piglets. Hypoxic-ischemic animals were randomly divided into four groups receiving 30 min after the insult: (1) normothermia and vehicle administration; (2) normothermia and cannabidiol administration; (3) hypothermia and vehicle administration; and (4) hypothermia and cannabidiol administration. Six hours after treatment, brains were processed to quantify the number of damaged neurons by Nissl staining. Proton nuclear magnetic resonance spectra were obtained and analyzed for lactate, N-acetyl-aspartate and glutamate. Metabolite ratios were calculated to assess neuronal damage (lactate/N-acetyl-aspartate) and excitotoxicity (glutamate/Nacetyl-aspartate). Western blot studies were performed to quantify protein nitrosylation (oxidative stress), content of caspase-3 (apoptosis) and TNFα (inflammation). Individually, the hypothermia and the cannabidiol treatments reduced the glutamate/Nacetyl-aspartate ratio, as well as TNFα and oxidized protein levels in newborn piglets subjected to hypoxic-ischemic insult. Also, both therapies reduced the number of necrotic neurons and prevented an increase in lactate/N-acetyl-aspartate ratio. The combined effect of hypothermia and cannabidiol on excitotoxicity, inflammation and oxidative stress, and on cell damage, was greater than either hypothermia or cannabidiol alone. The present study demonstrated that cannabidiol and hypothermia act complementarily and show additive effects on the main factors leading to hypoxic-ischemic brain damage if applied shortly after the insult. PMID:27462203

  13. 17β-Estradiol protects against acetaminophen-overdose-induced acute oxidative hepatic damage and increases the survival rate in mice.

    PubMed

    Chandrasekaran, Victor Raj Mohan; Periasamy, Srinivasan; Liu, Li-Lian; Liu, Ming-Yie

    2011-01-01

    Acetaminophen overdose causes acute liver injury or even death in both humans and experimental animals. We investigated the effect of 17β-estradiol against acetaminophen-induced acute liver injury and mortality in mice. Male mice were given acetaminophen (p-acetamidophenol; 300 mg/kg; orally) to induce acute liver injury. Acetaminophen significantly increased the levels of aspartate transaminase, alanine transaminase, myeloperoxidase, lipid peroxidation, and glutathione reductase, but it decreased superoxide dismutase, catalase, and glutathione. In addition, acetaminophen-induced mortality began 4h post-treatment, and all mice died within 9h. 17β-Estradiol (200 μg/kg; i.p.) protected against acetaminophen-induced oxidative hepatic damage by inhibiting neutrophil infiltration and stimulating the antioxidant defense system. However, 17β-estradiol did not affect acetaminophen-induced glutathione depletion or increased glutathione reductase activity. We conclude that 17β-estradiol specifically attenuates acute hepatic damage and decreases mortality in acetaminophen-overdosed male mice.

  14. Hippocampal damage and cytoskeletal disruption resulting from impaired energy metabolism. Implications for Alzheimer disease.

    PubMed

    Geddes, J W; Pang, Z; Wiley, D H

    1996-01-01

    To determine if impaired energy metabolism might contribute to some aspects of Alzheimer disease (AD), including the vulnerability of the CA1 region of the hippocampal formation and the altered cytoskeleton evident in neurofibrillary tangles, we examined the effects of metabolic poisons on neuronal damage and cytoskeletal disruption in the hippocampal formation. Intrahippocampal injection of 3-nitropropionic acid (3-NP) and malonic acid resulted in neuronal death, particularly in CA1. Cytoskeletal disruption included loss of dendritic MAP2, but sparing of axonal gamma. MK-801 (a noncompetitive NMDA receptor antagonist) did not atentuate the lesions produced by intrahippocampal injection of malonate. MK-801, however, was effective against intrastriatal malonate. Acute systemic 3-NP resulted in neuronal damage and cytoskeletal disruption in the CA1 region of the hippocampal formation, including an extensive loss of MAP2 immuno-reactivity, but sparing of gamma. The neuronal loss in CA1 was delayed as compared to striatum. Chronic intraventricular infusion of 3-NP produced a different pattern of neuronal damage. Loss of gamma-1 immuno-reactivity was observed in CA3 and CA1 s. orients, whereas MAP2 immunostaining was preserved. These results demonstrate that chronic and acute administration of metabolic inhibitors produce distinct patterns of neuronal damage and cytoskeletal disruption. The results further suggest a differential involvement of the NMDA receptor in malonate-induced neuronal damage in striatum as compared to the hippocampus. The pattern of neuronal damage and cytoskeletal disruption observed following acute metabolic impairment resembled some aspects of neurofibrillary pathology in AD, but did not result in gamma hyperphosphorylation.

  15. Tumor suppressor p53 induces miR-15a processing to inhibit neuronal apoptosis inhibitory protein (NAIP) in the apoptotic response DNA damage in breast cancer cell

    PubMed Central

    Yang, Li; Zhao, Wei; Wei, Ping; Zuo, Wenshu; Zhu, Shouhui

    2017-01-01

    This study was aimed to investigate the functional role of miR-15a in breast cancer cells in response to DNA damage and to illustrate the possible potential underlying molecular mechanism(s). Human breast cancer cell lines MCF-7 cells and/or MDA-MB-231 cells were pre-treated with or without bleomycin. Cells were transfected with corresponding vectors. qRT-PCR was used to detect the expression of mRNA or miRNA, and immunoprecipitation and immunoblot analysis were performed to explore the status of protein association. Cell apoptosis was analyzed with flow cytometry. The results showed that neuronal apoptosis inhibitory protein (NAIP) was negatively regulated by p53 in MCF-7 cells, and NAIP expression was still high in bleomycin-treated MCF-7 cells. In addition, we observed that miR-15a expression was regulated by p53, and the effects of miR-15a on DNA damage was also mediated by p53. Furthermore, the results revealed that the cell apoptosis was mediated by miR-15a. Taken together, this study reveals that p53 negatively regulates NAIP expression by targeting miR-15a processing from primary into precursor miRNA in breast cancer. PMID:28337296

  16. Oxidative DNA damage after acute exposure to arsenite and monomethylarsonous acid in biomethylation-deficient human cells.

    PubMed

    Orihuela, Ruben; Kojima, Chikara; Tokar, Erik J; Person, Rachel J; Xu, Yuanyuan; Qu, Wei; Waalkes, Michael P

    2013-07-01

    The carcinogen inorganic arsenic (iAs) undergoes biomethylation (BMT) in some cells. The methylated metabolite, monomethylarsonous (MMA(3+)), may cause oxidative DNA damage (ODD). With chronic iAs exposure, BMT-competent cells show ODD while BMT-deficient do not. To further define these events, we studied ODD produced by acute iAs or MMA(3+) in the BMT-deficient human prostate cell line, RWPE-1. ODD, measured by the immuno-spin trapping method, was assessed after exposure to iAs or MMA(3+) alone, with the arsenic BMT inhibitor selenite or after glutathione (GSH) depletion. The expression of oxidative stress-related genes (HO-1, SOD-1, SOD-2, Nrf2 and Keap-1) was also assessed. Exposure to iAs at 24 h (0-20 µM), stimulated ODD only at levels above the LC50 of a 48 h exposure (17 µM). If iAs induced ODD, it also activated oxidative stress-related genes. Selenium did not alter iAs-induced ODD. MMA(3+) at 24 h (0-0.5 µM) caused ODD at levels below the LC50 of a 48 h exposure (1.5 µM), which were greatly increased by GSH depletion but not selenite. MMA(3+) induced ODD at levels not activating oxidant stress response genes. Overall, iAs induced ODD in BMT-deficient cells only at toxic levels. MMA(3+) caused ODD at non-toxic levels, independently of cellular BMT capacity and in a fashion not requiring further BMT.

  17. Brainstem Neurons Survive the Identical Ischemic Stress That Kills Higher Neurons: Insight to the Persistent Vegetative State

    PubMed Central

    Brisson, C. Devin; Hsieh, Yi-Ting; Kim, Danielle; Jin, Albert Y.; Andrew, R. David

    2014-01-01

    Global ischemia caused by heart attack, pulmonary failure, near-drowning or traumatic brain injury often damages the higher brain but not the brainstem, leading to a ‘persistent vegetative state’ where the patient is awake but not aware. Approximately 30,000 U.S. patients are held captive in this condition but not a single research study has addressed how the lower brain is preferentially protected in these people. In the higher brain, ischemia elicits a profound anoxic depolarization (AD) causing neuronal dysfunction and vasoconstriction within minutes. Might brainstem nuclei generate less damaging AD and so be more resilient? Here we compared resistance to acute injury induced from simulated ischemia by ‘higher’ hippocampal and striatal neurons versus brainstem neurons in live slices from rat and mouse. Light transmittance (LT) imaging in response to 10 minutes of oxygen/glucose deprivation (OGD) revealed immediate and acutely damaging AD propagating through gray matter of neocortex, hippocampus, striatum, thalamus and cerebellar cortex. In adjacent brainstem nuclei, OGD-evoked AD caused little tissue injury. Whole-cell patch recordings from hippocampal and striatal neurons under OGD revealed sudden membrane potential loss that did not recover. In contrast brainstem neurons from locus ceruleus and mesencephalic nucleus as well as from sensory and motor nuclei only slowly depolarized and then repolarized post-OGD. Two-photon microscopy confirmed non-recoverable swelling and dendritic beading of hippocampal neurons during OGD, while mesencephalic neurons in midbrain appeared uninjured. All of the above responses were mimicked by bath exposure to 100 µM ouabain which inhibits the Na+/K+ pump or to 1–10 nM palytoxin which converts the pump into an open cationic channel. Therefore during ischemia the Na+/K+ pump of higher neurons fails quickly and extensively compared to naturally resilient hypothalamic and brainstem neurons. The selective survival of lower

  18. Four types of inorganic nanoparticles stimulate the inflammatory reaction in brain microglia and damage neurons in vitro.

    PubMed

    Xue, Yang; Wu, Jie; Sun, Jiao

    2012-10-17

    Once nanoparticles enter the central nervous system (CNS), they immediately encounter a complex environment of resident microglial immune cell and neurons. In the present study, NPs of 20-60nm in diameter (SiO(2)-NPs, TiO(2)-NPs, HAP-NPs and Fe(3)O(4)-NPs) were evaluated for their ability to induce microglia-mediated neurodegeneration. The microglia were directly exposed to NPs. The results showed that both TiO(2)-NPs and HAP-NPs induced significant iNOS expression, resulting in NO release from the microglia. The expression levels of MCP-1 and MIP-1α were also upregulated. These activation effects were accompanied by the activation of the transcription factor NF-κB. In addition, the secretion levels of TNF-α, IL-1β and IL-6 were variably increased by all four NPs. Subsequently, the cell-free supernatants from microglia monocultures were harvested and tested for their ability to stimulate PC12 cells. The results demonstrated that microglia-derived soluble factors induced by TiO(2)-NPs suppressed Th gene expression, and those by TiO(2)-NPs and HAP-NPs caused cytotoxicity in PC12 cells. Taken together, these results suggest that the NPs induced microglial activation and subsequently caused the release of proinflammatory factors that contributed to the dysfunction and cytotoxicity in PC12 cells.

  19. The ameliorative potential of ethanolic extract of propolis on hematotoxicity and structural neuronal damage in hyperthermia-exposed rats

    PubMed Central

    Mohamed, Wafaa Abdou Mohamed; Ismail, Tamer; Farouk, Sameh

    2016-01-01

    Objective(s): Hyperthermia is one of the most common environmental stressors that affect multi-biological systems in the body including the central nervous system as well as the hematopoietic organs. The objective of the present study was to investigate the protective role of ethanolic extract of propolis (EEP) on some selective stress markers, hematological, biochemical, and histopathological changes in rats subjected to hyperthermia (40 °C/12 hr). Materials and Methods: The experimental groups (10 rats each) were classified as follows; Group A; control, (C), was kept at a controlled room temperature (25±5 °C). Group B; ethanolic extract of propolis, (EEP), was fed a basal diet supplemented with 3 g EEP/kg diet for 10 days. Group C; heat stress, (HS), was fed a basal diet for 10 days, and then exposed to high temperature (40±1 °C) for 12 hr. Group D; co-exposed, (EEP+HS) was fed a basal diet supplemented with 3 g EEP/kg diet for 10 days, and then subjected to high temperature (40±1 °C) for 12 hr. At the end of the experimental period, animals were decapitated; blood and tissue samples (brain and spleen) were collected for hematological, biochemical, and histopathological examination. Results: EEP at a dose of 3 g/kg diet has a potent protective effect against hematotoxicity and brain damage as well as oxidative stress induced by heat stress in rats. Conclusion: The present study indicates that pre-treatment with EEP protects from hematotoxicity and neurological damage induced by high environmental temperature. PMID:27746870

  20. Loss of extracellular superoxide dismutase leads to acute lung damage in the presence of ambient air: a potential mechanism underlying adult respiratory distress syndrome.

    PubMed

    Gongora, Maria Carolina; Lob, Heinrich E; Landmesser, Ulf; Guzik, Tomasz J; Martin, W David; Ozumi, Kiyoski; Wall, Susan M; Wilson, David Scott; Murthy, Niren; Gravanis, Michael; Fukai, Tohru; Harrison, David G

    2008-10-01

    The extracellular superoxide dismutase 3 (SOD3) is highly expressed in both blood vessels and lungs. In different models of pulmonary injury, SOD3 is reduced; however, it is unclear whether this contributes to lung injury. To study the role of acute SOD3 reduction in lung injury, the SOD3 gene was deleted in adult mice by using the Cre-Lox technology. Acute reduction of SOD3 led to a fivefold increase in lung superoxide, marked inflammatory cell infiltration, a threefold increase in the arterial-alveolar gradient, respiratory acidosis, histological changes similar to those observed in adult respiratory distress syndrome, and 85% mortality. Treatment with the SOD mimetic MnTBAP and intranasal administration of SOD-containing polyketal microparticles reduced mortality, prevented the histological alterations, and reduced lung superoxide levels. To understand how mice with the SOD3 embryonic deletion survived without lung injury, gene array analysis was performed. These data demonstrated the up-regulation of 37 genes and down-regulation of nine genes, including those involved in cell signaling, inflammation, and gene transcription in SOD3-/- mice compared with either mice with acute SOD3 reduction or wild-type controls. These studies show that SOD3 is essential for survival in the presence of ambient oxygen and that acute loss of this enzyme can lead to severe lung damage. Strategies either to prevent SOD3 inactivation or to augment its levels might prove useful in the treatment of acute lung injury.

  1. Acute p38-mediated inhibition of NMDA-induced outward currents in hippocampal CA1 neurons by interleukin-1beta.

    PubMed

    Zhang, Ruoyu; Sun, Li; Hayashi, Yoshinori; Liu, Xia; Koyama, Susumu; Wu, Zhou; Nakanishi, Hiroshi

    2010-04-01

    Interleukin-1beta (IL-1beta) is a potent pro-inflammatory cytokine that is primarily produced by microglia in the brain. IL-1beta inhibits N-methyl-d-aspartate (NMDA)-induced outward currents (I(NMDA-OUT)) through IL-1 type I receptor (IL-1RI) in hippocampal CA1 neurons (Zhang, R., Yamada, J., Hayashi, Y., Wu, Z, Koyama, S., Nakanishi, H., 2008. Inhibition of NMDA-induced outward currents by interleukin-1beta in hippocampal neurons, Biochem. Biophys. Res. Commun. 372, 816-820). Although IL-1RI is associated with mitogen-activated protein kinases, their involvement in the effect of IL-1beta on I(NMDA-OUT) remains unclear. In the present study, we demonstrate that IL-1beta caused activation of p38 mitogen-activated protein kinase and that the p38 inhibitor SB203580 significantly blocked the effect of IL-1beta on I(NMDA-OUT) in hippocampal CA1 neurons. Furthermore, the intracellular perfusion of active recombinant p38alpha significantly decreased the mean amplitude of I(NMDA-OUT). In neurons prepared from inflamed hippocampus, the mean amplitude of I(NMDA-OUT) was significantly reduced. In the inflamed hippocampus, IL-1beta and IL-1RI were expressed mainly in microglia and neurons, respectively. These results suggest that IL-1beta increases the excitability of hippocampal CA1 neurons in the p38-dependent inhibition of I(NMDA-OUT).

  2. Intrathecal infusion of BMAA induces selective motor neuron damage and astrogliosis in the ventral horn of the spinal cord

    PubMed Central

    Yin, Hong Z.; Yu, Stephen; Hsu, Cheng-I; Liu, Joe; Acab, Allan; Wu, Richard; Tao, Anna; Chiang, Benjamin J.; Weiss, John H.

    2014-01-01

    The neurotoxin beta-N-methylamino-L-alanine (BMAA) was first identified as a “toxin of interest” in regard to the amyotrophic lateral sclerosis–Parkinsonism Dementia Complex of Guam (ALS/PDC); studies in recent years highlighting widespread environmental sources of BMAA exposure and providing new clues to toxic mechanisms have suggested possible relevance to sporadic ALS as well. However, despite clear evidence of uptake into tissues and a range of toxic effects in cells and animals, an animal model in which BMAA induces a neurodegenerative picture resembling ALS is lacking, possibly in part reflecting limited understanding of critical factors pertaining to its absorption, biodistribution and metabolism. To bypass some of these issues and ensure delivery to a key site of disease pathology, we examined effects of prolonged (30 day) intrathecal infusion in wild type (WT) rats, and rats harboring the familial ALS associated G93A SOD1 mutation, over an age range (80±2 to 110±2 days) during which the G93A rats are developing disease pathology yet remain asymptomatic. The BMAA exposures induced changes that in many ways resembles those seen in the G93A rats, with degenerative changes in ventral horn motor neurons (MNs) with relatively little dorsal horn pathology, marked ventral horn astrogliosis and increased 3-nitrotyrosine labeling in and surrounding MNs, a loss of labeling for the astrocytic glutamate transporter, GLT-1, surrounding MNs, and mild accumulation and aggregation of TDP-43 in the cytosol of some injured and degenerating MNs. Thus, prolonged intrathecal infusion of BMAA can reproduce a picture in spinal cord incorporating many of the pathological hallmarks of diverse forms of human ALS, including substantial restriction of overt pathological changes to the ventral horn, consistent with the possibility that environmental BMAA exposure could be a risk factor and/or contributor to some human disease. PMID:24918341

  3. Intrathecal infusion of BMAA induces selective motor neuron damage and astrogliosis in the ventral horn of the spinal cord.

    PubMed

    Yin, Hong Z; Yu, Stephen; Hsu, Cheng-I; Liu, Joe; Acab, Allan; Wu, Richard; Tao, Anna; Chiang, Benjamin J; Weiss, John H

    2014-11-01

    The neurotoxin beta-N-methylamino-l-alanine (BMAA) was first identified as a "toxin of interest" in regard to the amyotrophic lateral sclerosis-Parkinsonism Dementia Complex of Guam (ALS/PDC); studies in recent years highlighting widespread environmental sources of BMAA exposure and providing new clues to toxic mechanisms have suggested possible relevance to sporadic ALS as well. However, despite clear evidence of uptake into tissues and a range of toxic effects in cells and animals, an animal model in which BMAA induces a neurodegenerative picture resembling ALS is lacking, possibly in part reflecting limited understanding of critical factors pertaining to its absorption, biodistribution and metabolism. To bypass some of these issues and ensure delivery to a key site of disease pathology, we examined effects of prolonged (30day) intrathecal infusion in wild type (WT) rats, and rats harboring the familial ALS associated G93A SOD1 mutation, over an age range (80±2 to 110±2days) during which the G93A rats are developing disease pathology yet remain asymptomatic. The BMAA exposures induced changes that in many ways resemble those seen in the G93A rats, with degenerative changes in ventral horn motor neurons (MNs) with relatively little dorsal horn pathology, marked ventral horn astrogliosis and increased 3-nitrotyrosine labeling in and surrounding MNs, a loss of labeling for the astrocytic glutamate transporter, GLT-1, surrounding MNs, and mild accumulation and aggregation of TDP-43 in the cytosol of some injured and degenerating MNs. Thus, prolonged intrathecal infusion of BMAA can reproduce a picture in spinal cord incorporating many of the pathological hallmarks of diverse forms of human ALS, including substantial restriction of overt pathological changes to the ventral horn, consistent with the possibility that environmental BMAA exposure could be a risk factor and/or contributor to some human disease.

  4. ApoB100/LDLR-/- Hypercholesterolaemic Mice as a Model for Mild Cognitive Impairment and Neuronal Damage

    PubMed Central

    Ramírez, Carlos; Sierra, Saleta; Tercero, Inmaculada; Vázquez, Jose Antonio; Pineda, Antonia; Manrique, Tatiana; Burgos, Javier S.

    2011-01-01

    Recent clinical findings support the notion that the progressive deterioration of cholesterol homeostasis is a central player in Alzheimer's disease (AD). Epidemiological studies suggest that high midlife plasma total cholesterol levels are associated with an increased risk of AD. This paper reports the plasma cholesterol concentrations, cognitive performance, locomotor activity and neuropathological signs in a murine model (transgenic mice expressing apoB100 but knockout for the LDL receptor [LDLR]) of human familial hypercholesterolaemia (FH). From birth, these animals have markedly elevated LDL-cholesterol and apolipoprotein B100 (apoB100) levels. These transgenic mice were confirmed to have higher plasma cholesterol concentrations than wild-type mice, an effect potentiated by aging. Further, 3-month-old transgenic mice showed cholesterol (total and fractions) concentrations considerably higher than those of 18-month-old wild-type mice. The hypercholesterolaemia of the transgenic mice was associated with a clear locomotor deficit (as determined by rotarod, grip strength and open field testing) and impairment of the episodic-like memory (determined by the integrated memory test). This decline in locomotor activity and cognitive status was associated with neuritic dystrophy and/or the disorganization of the neuronal microtubule network, plus an increase in astrogliosis and lipid peroxidation in the brain regions associated with AD, such as the motor and lateral entorhinal cortex, the amygdaloid basal nucleus, and the hippocampus. Aortic atherosclerotic lesions were positively correlated with age, although potentiated by the transgenic genotype, while cerebral β-amyloidosis was positively correlated with genetic background rather than with age. These findings confirm hypercholesterolaemia as a key biomarker for monitoring mild cognitive impairment, and shows these transgenic mice can be used as a model for cognitive and psycho-motor decline. PMID:21829488

  5. Glycine Administration Alters MAPK Signaling Pathways and Causes Neuronal Damage in Rat Brain: Putative Mechanisms Involved in the Neurological Dysfunction in Nonketotic Hyperglycinemia.

    PubMed

    Moura, Alana Pimentel; Parmeggiani, Belisa; Gasparotto, Juciano; Grings, Mateus; Fernandez Cardoso, Gabriela Miranda; Seminotti, Bianca; Moreira, José Cláudio Fonseca; Gelain, Daniel Pens; Wajner, Moacir; Leipnitz, Guilhian

    2017-01-03

    High glycine (GLY) levels have been suggested to induce neurotoxic effects in the central nervous system of patients with nonketotic hyperglycinemia (NKH). Since the mechanisms involved in the neuropathophysiology of NKH are not totally established, we evaluated the effect of a single intracerebroventricular administration of GLY on the content of proteins involved in neuronal damage and inflammatory response, as well as on the phosphorylation of the MAPK p38, ERK1/2, and JNK in rat striatum and cerebral cortex. We also examined glial fibrillary acidic protein (GFAP) staining, a marker of glial reactivity. The parameters were analyzed 30 min or 24 h after GLY administration. GLY decreased Tau phosphorylation in striatum and cerebral cortex 30 min and 24 h after its administration. On the other hand, synaptophysin levels were decreased in striatum at 30 min and in cerebral cortex at 24 h after GLY injection. GLY also decreased the phosphorylation of p38, ERK1/2, and JNK 30 min after its administration in both brain structures. Moreover, GLY-induced decrease of p38 phosphorylation in striatum was attenuated by N-methyl-D-aspartate receptor antagonist MK-801. In contrast, synuclein, NF-κB, iκB, inducible nitric oxide synthase and nitrotyrosine content, and GFAP immunostaining were not altered by GLY infusion. It may be presumed that the decreased phosphorylation of MAPK associated with alterations of markers of neuronal injury induced by GLY may contribute to the neurological dysfunction observed in NKH.

  6. Sublethal Total Body Irradiation Leads to Early Cerebellar Damage and Oxidative Stress

    DTIC Science & Technology

    2010-01-01

    and myogenic differentiation of hematopoietic progenitor cells in inflammatory myopathies . J Neuropathol Exp Neurol 2008; 67(7): 711-19. [26] Porto...following sublethal TBI. Oxidative stress, inflammatory response and calcium neurotoxicity-associated mechanisms are involved in radiation-induced...neuronal damage. Keyword: Calcium, cerebellum, inflammatory response, oxidative stress, Purkinje cell, sublethal radiation. INTRODUCTION Acute radiation

  7. Neurokinin B Causes Acute GnRH Secretion and Repression of GnRH Transcription in GT1–7 GnRH Neurons

    PubMed Central

    Glidewell-Kenney, Christine A.; Shao, Paul P.; Iyer, Anita K.; Grove, Anna M. H.; Meadows, Jason D.

    2013-01-01

    Genetic studies in human patients with idiopathic hypogonadotropic hypogonadism (IHH) identified mutations in the genes that encode neurokinin B (NKB) and the neurokinin 3 receptor (NK3R). However, determining the mechanism whereby NKB regulates gonadotropin secretion has been difficult because of conflicting results from in vivo studies investigating the luteinizing hormone (LH) response to senktide, a NK3R agonist. NK3R is expressed in a subset of GnRH neurons and in kisspeptin neurons that are known to regulate GnRH secretion. Thus, one potential source of inconsistency is that NKB could produce opposing direct and indirect effects on GnRH secretion. Here, we employ the GT1-7 cell model to elucidate the direct effects of NKB on GnRH neuron function. We find that GT1-7 cells express NK3R and respond to acute senktide treatment with c-Fos induction and increased GnRH secretion. In contrast, long-term senktide treatment decreased GnRH secretion. Next, we focus on the examination of the mechanism underlying the long-term decrease in secretion and determine that senktide treatment represses transcription of GnRH. We further show that this repression of GnRH transcription may involve enhanced c-Fos protein binding at novel activator protein-1 (AP-1) half-sites identified in enhancer 1 and the promoter, as well as chromatin remodeling at the promoter of the GnRH gene. These data indicate that NKB could directly regulate secretion from NK3R-expressing GnRH neurons. Furthermore, whether the response is inhibitory or stimulatory toward GnRH secretion could depend on the history or length of exposure to NKB because of a repressive effect on GnRH transcription. PMID:23393128

  8. Sex differences in skin carotenoid deposition and acute UVB-induced skin damage in SKH-1 hairless mice after consumption of tangerine tomatoes

    PubMed Central

    Kopec, Rachel E.; Schick, Jonathan; Tober, Kathleen L.; Riedl, Ken M.; Francis, David M.; Young, Gregory S.; Schwartz, Steven J.; Oberyszyn, Tatiana M.

    2015-01-01

    Scope UVB exposure, a major factor in the development of skin cancer, has differential sex effects. Tomato product consumption reduces the intensity of UVB-induced erythema in humans, but the mechanisms are unknown. Methods and results Four week old SKH-1 hairless mice (40 females, 40 males) were divided into two feeding groups (control or with 10% tangerine tomatoes naturally rich in UV-absorbing phytoene and phytofluene) and two UV exposure groups (with or without UV). After 10 weeks of feeding, the UV group was exposed to a single UV dose and sacrificed 48 hours later. Blood and dorsal skin samples were taken for carotenoid analysis. Dorsal skin was harvested to assess sex and UV effects on carotenoid deposition, inflammation (skinfold thickness, myeloperoxidase levels) and DNA damage (cyclobutane pyrimidine dimers, p53). Females had significantly higher levels of both skin and blood carotenoids relative to males. UV exposure significantly reduced skin carotenoid levels in females but not males. Tomato consumption attenuated acute UV-induced increases in CPD in both sexes, and reduced myeloperoxidase activity and % p53 positive epidermal cells in males. Conclusion Tangerine tomatoes mediate acute UV-induced skin damage in SKH-1 mice via reduced DNA damage in both sexes, and through reduced inflammation in males. PMID:26394800

  9. Extracellular histones are essential effectors of C5aR- and C5L2-mediated tissue damage and inflammation in acute lung injury.

    PubMed

    Bosmann, Markus; Grailer, Jamison J; Ruemmler, Robert; Russkamp, Norman F; Zetoune, Firas S; Sarma, J Vidya; Standiford, Theodore J; Ward, Peter A

    2013-12-01

    We investigated how complement activation promotes tissue injury and organ dysfunction during acute inflammation. Three models of acute lung injury (ALI) induced by LPS, IgG immune complexes, or C5a were used in C57BL/6 mice, all models requiring availability of both C5a receptors (C5aR and C5L2) for full development of ALI. Ligation of C5aR and C5L2 with C5a triggered the appearance of histones (H3 and H4) in bronchoalveolar lavage fluid (BALF). BALF from humans with ALI contained H4 histone. Histones were absent in control BALF from healthy volunteers. In mice with ALI, in vivo neutralization of H4 with IgG antibody reduced the intensity of ALI. Neutrophil depletion in mice with ALI markedly reduced H4 presence in BALF and was highly protective. The direct lung damaging effects of extracellular histones were demonstrated by airway administration of histones into mice and rats (Sprague-Dawley), which resulted in ALI that was C5a receptor-independent, and associated with intense inflammation, PMN accumulation, damage/destruction of alveolar epithelial cells, together with release into lung of cytokines/chemokines. High-resolution magnetic resonance imaging demonstrated lung damage, edema and consolidation in histone-injured lungs. These studies confirm the destructive C5a-dependent effects in lung linked to appearance of extracellular histones.

  10. Orally Administrated Ascorbic Acid Suppresses Neuronal Damage and Modifies Expression of SVCT2 and GLUT1 in the Brain of Diabetic Rats with Cerebral Ischemia-Reperfusion

    PubMed Central

    Iwata, Naohiro; Okazaki, Mari; Xuan, Meiyan; Kamiuchi, Shinya; Matsuzaki, Hirokazu; Hibino, Yasuhide

    2014-01-01

    Diabetes mellitus is known to exacerbate cerebral ischemic injury. In the present study, we investigated antiapoptotic and anti-inflammatory effects of oral supplementation of ascorbic acid (AA) on cerebral injury caused by middle cerebral artery occlusion and reperfusion (MCAO/Re) in rats with streptozotocin-induced diabetes. We also evaluated the effects of AA on expression of sodium-dependent vitamin C transporter 2 (SVCT2) and glucose transporter 1 (GLUT1) after MCAO/Re in the brain. The diabetic state markedly aggravated MCAO/Re-induced cerebral damage, as assessed by infarct volume and edema. Pretreatment with AA (100 mg/kg, p.o.) for two weeks significantly suppressed the exacerbation of damage in the brain of diabetic rats. AA also suppressed the production of superoxide radical, activation of caspase-3, and expression of proinflammatory cytokines (tumor necrosis factor-α and interleukin-1β) in the ischemic penumbra. Immunohistochemical staining revealed that expression of SVCT2 was upregulated primarily in neurons and capillary endothelial cells after MCAO/Re in the nondiabetic cortex, accompanied by an increase in total AA (AA + dehydroascorbic acid) in the tissue, and that these responses were suppressed in the diabetic rats. AA supplementation to the diabetic rats restored these responses to the levels of the nondiabetic rats. Furthermore, AA markedly upregulated the basal expression of GLUT1 in endothelial cells of nondiabetic and diabetic cortex, which did not affect total AA levels in the cortex. These results suggest that daily intake of AA attenuates the exacerbation of cerebral ischemic injury in a diabetic state, which may be attributed to anti-apoptotic and anti-inflammatory effects via the improvement of augmented oxidative stress in the brain. AA supplementation may protect endothelial function against the exacerbated ischemic oxidative injury in the diabetic state and improve AA transport through SVCT2 in the cortex. PMID:24739976

  11. Cortical excitatory neurons become protected from cell division during neurogenesis in an Rb family-dependent manner.

    PubMed

    Oshikawa, Mio; Okada, Kei; Nakajima, Kazunori; Ajioka, Itsuki

    2013-06-01

    Cell cycle dysregulation leads to abnormal proliferation and cell death in a context-specific manner. Cell cycle progression driven via the Rb pathway forces neurons to undergo S-phase, resulting in cell death associated with the progression of neuronal degeneration. Nevertheless, some Rb- and Rb family (Rb, p107 and p130)-deficient differentiating neurons can proliferate and form tumors. Here, we found in mouse that differentiating cerebral cortical excitatory neurons underwent S-phase progression but not cell division after acute Rb family inactivation in differentiating neurons. However, the differentiating neurons underwent cell division and proliferated when Rb family members were inactivated in cortical progenitors. Differentiating neurons generated from Rb(-/-); p107(-/-); p130(-/-) (Rb-TKO) progenitors, but not acutely inactivated Rb-TKO differentiating neurons, activated the DNA double-strand break (DSB) repair pathway without increasing trimethylation at lysine 20 of histone H4 (H4K20), which has a role in protection against DNA damage. The activation of the DSB repair pathway was essential for the cell division of Rb-TKO differentiating neurons. These results suggest that newly born cortical neurons from progenitors become epigenetically protected from DNA damage and cell division in an Rb family-dependent manner.

  12. Biochemical modifications and neuronal damage in brain of young and adult rats after long-term exposure to mobile phone radiations.

    PubMed

    Motawi, Tarek K; Darwish, Hebatallah A; Moustafa, Yasser M; Labib, Mohammed M

    2014-11-01

    This study investigated the effect of exposure to mobile phone radiations on oxidative stress and apoptosis in brain of rats. Rats were allocated into six groups (three young and three adult). Groups 1 and 4 were not subjected to the radiation source and served as control groups. In groups 2 and 5, the mobile phones were only connected to the global system for mobile communication, while in groups 3 and 6, the option of calling was in use. Microwaves were generated by a mobile test phone (SAR = 1.13 W/kg) during 60 days (2 h/day). Significant increments in conjugated dienes, protein carbonyls, total oxidant status, and oxidative stress index along with a significant reduction of total antioxidant capacity levels were evident after exposure. Bax/Bcl-2 ratio, caspase-3 activity, and tumor necrosis factor-alpha level were enhanced, whereas no DNA fragmentation was detected. The relative brain weight of young rats was greatly affected, and histopathological examination reinforced the neuronal damage. The study highlights the detrimental effects of mobile phone radiations on brain during young and adult ages. The interaction of these radiations with brain is via dissipating its antioxidant status and/or triggering apoptotic cell death.

  13. The Mammalian Brain in the Electromagnetic Fields Designed by Man with Special Reference to Blood-Brain Barrier Function, Neuronal Damage and Possible Physical Mechanisms

    NASA Astrophysics Data System (ADS)

    Salford, L. G.; Nittby, H.; Brun, A.; Grafström, G.; Malmgren, L.; Sommarin, M.; Eberhardt, J.; Widegren, B.; Persson, B. R.

    Life on earth was formed during billions of years, exposed to,and shaped by the original physical forces such as gravitation, cosmic irradiation, atmospheric electric fields and the terrestrial magnetism. The Schumann resonances at 7.4 Hz are an example of oscillations possibly important for life. The existing organisms are created to function in harmony with these forces. However, in the late 19th century mankind introduced the use of electricity, in the early 20th century long-wave radio and in the 1940-ies short-wave radio. High frequency RF was introduced in the 50-ies as FM and television and during the very last decades, microwaves of the modern communication society spread around the world. Today, however, one third of the world's population is owner of the microwave-producing mobile phones and an even larger number is exposed to the cordless RF emitting systems. To what extent are all living organisms affected by these, almost everywhere present radio freque ncy fields? And what will be the effects of many years of continuing exposure? Since 1988 our group has studied the effects upon the mammalian blood-brain barrier (BBB) in rats by non-thermal radio frequency electromagnetic fields (RF-EMF). These have been shown to cause significantly increased leakage of the rats' own blood albumin through the BBB of exposed rats, at energy levels of 1W/kg and below, as compared to non-exposed animals in a total series of about two thousand animals.-6)} One remarkable observation is the fact that the lowest energy levels, with whole-body average power densities below 10mW/kg, give rise to the most pronounced albumin leakage. If mobile communication, even at extremely low energy levels, causes the users' own albumin to leak out through the BBB, also other unwanted and toxic molecules in the blood, may leak into the brain tissue and concentrate in and damage the neurons and glial cells of the brain. In later studies we have shown that a 2-h exposure to GSM 915 MHz, at

  14. Patch-clamp recordings of rat neurons from acute brain slices of the somatosensory cortex during magnetic stimulation

    PubMed Central

    Pashut, Tamar; Magidov, Dafna; Ben-Porat, Hana; Wolfus, Shuki; Friedman, Alex; Perel, Eli; Lavidor, Michal; Bar-Gad, Izhar; Yeshurun, Yosef; Korngreen, Alon

    2014-01-01

    Although transcranial magnetic stimulation (TMS) is a popular tool for both basic research and clinical applications, its actions on nerve cells are only partially understood. We have previously predicted, using compartmental modeling, that magnetic stimulation of central nervous system neurons depolarized the soma followed by initiation of an action potential in the initial segment of the axon. The simulations also predict that neurons with low current threshold are more susceptible to magnetic stimulation. Here we tested these theoretical predictions by combining in vitro patch-clamp recordings from rat brain slices with magnetic stimulation and compartmental modeling. In agreement with the modeling, our recordings demonstrate the dependence of magnetic stimulation-triggered action potentials on the type and state of the neuron and its orientation within the magnetic field. Our results suggest that the observed effects of TMS are deeply rooted in the biophysical properties of single neurons in the central nervous system and provide a framework both for interpreting existing TMS data and developing new simulation-based tools and therapies. PMID:24917788

  15. Effects of grape seed polyphenols on oxidative damage in liver tissue of acutely and chronically exercised rats.

    PubMed

    Belviranlı, Muaz; Gökbel, Hakkı; Okudan, Nilsel; Büyükbaş, Sadık

    2013-05-01

    The objective of the present study was to investigate the effects of grape seed extract (GSE) supplementation on oxidative stress and antioxidant defense markers in liver tissue of acutely and chronically exercised rats. Rats were randomly assigned to six groups: Control (C), Control Chronic Exercise (CE), Control Acute Exercise (AE), GSE-supplemented Control (GC), GSE-supplemented Chronic Exercise(GCE) and GSE-supplemented Acute Exercise (GAE). Rats in the chronic exercise groups were subjected to a six-week treadmill running and in the acute exercise groups performed an exhaustive running. Rats in the GSE supplemented groups received GSE (100 mg.kg(-1) .day(-1) ) in drinking water for 6 weeks. Liver tissues of the rats were taken for the analysis of malondialdehyde (MDA), nitric oxide (NO) levels and total antioxidant activity (AOA) and xanthine oxidase (XO) activities. MDA levels decreased with GSE supplementation in control groups but increased in acute and chronic exercise groups compared to their non-supplemented control. NO levels increased with GSE supplementation. XO activities were higher in AE group compared to the CE group. AOA decreased with GSE supplementation. In conclusion, while acute exercise triggers oxidative stress, chronic exercise has protective role against oxidative stress. GSE has a limited antioxidant effect on exercise-induced oxidative stress in liver tissue.

  16. Dopamine Modulates Spike Timing-Dependent Plasticity and Action Potential Properties in CA1 Pyramidal Neurons of Acute Rat Hippocampal Slices

    PubMed Central

    Edelmann, Elke; Lessmann, Volkmar

    2011-01-01

    Spike timing-dependent plasticity (STDP) is a cellular model of Hebbian synaptic plasticity which is believed to underlie memory formation. In an attempt to establish a STDP paradigm in CA1 of acute hippocampal slices from juvenile rats (P15–20), we found that changes in excitability resulting from different slice preparation protocols correlate with the success of STDP induction. Slice preparation with sucrose containing ACSF prolonged rise time, reduced frequency adaptation, and decreased latency of action potentials in CA1 pyramidal neurons compared to preparation in conventional ASCF, while other basal electrophysiological parameters remained unaffected. Whereas we observed prominent timing-dependent long-term potentiation (t-LTP) to 171 ± 10% of controls in conventional ACSF, STDP was absent in sucrose prepared slices. This sucrose-induced STDP deficit could not be rescued by stronger STDP paradigms, applying either more pre- and/or postsynaptic stimuli, or by a higher stimulation frequency. Importantly, slice preparation with sucrose containing ACSF did not eliminate theta-burst stimulation induced LTP in CA1 in field potential recordings in our rat hippocampal slices. Application of dopamine (for 10–20 min) to sucrose prepared slices completely rescued t-LTP and recovered action potential properties back to levels observed in ACSF prepared slices. Conversely, acute inhibition of D1 receptor signaling impaired t-LTP in ACSF prepared slices. No similar restoring effect for STDP as seen with dopamine was observed in response to the β-adrenergic agonist isoproterenol. ELISA measurements demonstrated a significant reduction of endogenous dopamine levels (to 61.9 ± 6.9% of ACSF values) in sucrose prepared slices. These results suggest that dopamine signaling is involved in regulating the efficiency to elicit STDP in CA1 pyramidal neurons. PMID:22065958

  17. Electroacupuncture Reduces the Effects of Acute Noxious Stimulation on the Electrical Activity of Pain-Related Neurons in the Hippocampus of Control and Neuropathic Pain Rats

    PubMed Central

    Wang, Jun-Ying; Chen, Renbo; Feng, Xiu-Mei; Yan, Yaxia; Lippe, Irmgard Th.

    2016-01-01

    To study the effects of acupuncture analgesia on the hippocampus, we observed the effects of electroacupuncture (EA) and mitogen-activated protein kinase (MEK) inhibitor on pain-excited neurons (PENs) and pain-inhibited neurons (PINs) in the hippocampal area CA1 of sham or chronic constrictive injury (CCI) rats. The animals were randomly divided into a control, a CCI, and a U0126 (MEK1/2 inhibitor) group. In all experiments, we briefly (10-second duration) stimulated the sciatic nerve electrically and recorded the firing rates of PENs and PINs. The results showed that in both sham and CCI rats brief sciatic nerve stimulation significantly increased the electrical activity of PENs and markedly decreased the electrical activity of PINs. These effects were significantly greater in CCI rats compared to sham rats. EA treatment reduced the effects of the noxious stimulus on PENs and PINs in both sham and CCI rats. The effects of EA treatment could be inhibited by U0126 in sham-operated rats. The results suggest that EA reduces effects of acute sciatic nerve stimulation on PENs and PINs in the CA1 region of the hippocampus of both sham and CCI rats and that the ERK (extracellular regulated kinase) signaling pathway is involved in the modulation of EA analgesia. PMID:27833763

  18. Effect of interaction between acute administration of morphine and cannabinoid compounds on spontaneous excitatory and inhibitory postsynaptic currents of magnocellular neurons of supraoptic nucleus

    PubMed Central

    Yousefpour, Mitra; Naderi, Nima; Motamedi, Fereshteh

    2016-01-01

    Objective(s): Opioids and cannabinoids are two important compounds that have been shown to influence the activity of magnocellular neurons (MCNs) of supraoptic nucleus (SON). The interaction between opioidergic and cannabinoidergic systems in various structures of the brain and spinal cord is now well established, but not in the MCNs of SON. Materials and methods: In this study, whole cell patch clamp recording of neurons in rat brain slice was used to investigate the effect of acute morphine and cannabinoid administration on spontaneous inhibitory and excitatory spostsynaptic currents (sIPSCs and sEPSCs) in MCNs. Results: Bath application of morphine produced an increase in sEPSCs frequency and a decrease in sIPSCs frequency. In contrast, bath application of URB597 (fatty acid amide hydrolase (FAAH) inhibitor) produced a decrease in sEPSCs frequency but an increase in sIPSCs frequency. WIN55212-2 (cannabinoid receptor agonist) decreased both sIPSCs and sEPSCs frequencies of MCNs. Co-application of morphine and URB597 attenuated the effect of morphine on MCNs. Conclusion: Taken together, these data indicated that at the cellular level, pharmacological augmentation of endocannabinoids could attenuate morphine effects on MCNs. PMID:27482350

  19. Adult Bone Marrow Neural Crest Stem Cells and Mesenchymal Stem Cells Are Not Able to Replace Lost Neurons in Acute MPTP-Lesioned Mice

    PubMed Central

    Neirinckx, Virginie; Marquet, Alice; Coste, Cécile

    2013-01-01

    Adult bone marrow stroma contains multipotent stem cells (BMSC) that are a mixed population of mesenchymal and neural-crest derived stem cells. Both cells are endowed with in vitro multi-lineage differentiation abilities, then constituting an attractive and easy-available source of material for cell therapy in neurological disorders. Whereas the in vivo integration and differentiation of BMSC in neurons into the central nervous system is currently matter of debate, we report here that once injected into the striatum of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice, pure populations of either bone marrow neural crest stem cells (NCSC) or mesenchymal stem cells (MSC) survived only transiently into the lesioned brain. Moreover, they do not migrate through the brain tissue, neither modify their initial phenotype, while no recovery of the dopaminergic system integrity was observed. Consequently, we tend to conclude that MSC/NCSC are not able to replace lost neurons in acute MPTP-lesioned dopaminergic system through a suitable integration and/or differentiation process. Altogether with recent data, it appears that neuroprotective, neurotrophic and anti-inflammatory features characterizing BMSC are of greater interest as regards CNS lesions management. PMID:23741377

  20. Acute tianeptine treatment selectively modulates neuronal activation in the central nucleus of the amygdala and attenuates fear extinction.

    PubMed

    Godsil, B P; Bontempi, B; Mailliet, F; Delagrange, P; Spedding, M; Jay, T M

    2015-11-01

    Antidepressant drugs are commonly prescribed treatments for anxiety disorders, and there is growing interest in understanding how these drugs impact fear extinction because extinction learning is pivotal to successful exposure-based therapy (EBT). A key objective within this domain is understanding how antidepressants alter the activation of specific elements of the limbic-based network that governs such fear processing. Chronic treatment with the antidepressant tianeptine has been shown to reduce the acquisition of extinction learning in rats, yet the drug's acute influence on activation in prefrontal and amygdalar regions, and on extinction learning are not well understood. To assess its influence on cellular activation, rats were injected with tianeptine and Fos immunoreactivity was measured in these regions. Acute tianeptine treatment selectively altered Fos expression within subdivisions of the central nucleus of the amygdala (CEA) in a bidirectional manner that varied in relation to ongoing activation within the capsular subdivision and its prefrontal and intra-amygdalar inputs. This pattern of results suggests that the drug can conditionally modulate the activation of CEA subdivisions, which contain microcircuits strongly implicated in fear processing. The effect of acute tianeptine was also examined with respect to the acquisition, consolidation and expression of fear extinction in rats. Acute tianeptine attenuated extinction learning as well as the recall of extinction memory, which underscores that acute dosing with the drug could alter learning during EBT. Together these findings provide a new perspective for understanding the mechanism supporting tianeptine's clinical efficacy, as well as its potential influence on CEA-based learning mechanisms.

  1. Astroglial U87 Cells Protect Neuronal SH-SY5Y Cells from Indirect Effect of Radiation by Reducing DNA Damage and Inhibiting Fas Mediated Apoptotic Pathway in Coculture System.

    PubMed

    Saeed, Yasmeen; Rehman, Abdul; Xie, Bingjie; Xu, Jin; Hong, Ma; Hong, Qing; Deng, Yulin

    2015-08-01

    Recent studies provide the evidence that indirect effects of radiation could lead to neuronal cells death but underlying mechanism is not completely understood. On the other hand astroglial cells are known to protect neuronal cells against stress conditions in vivo and invitro. Yet, the fate of neuronal cells and the neuroprotective effect of coculture system (with glial cells) in response to indirect radiation exposure remain rarely discussed. Here, we purpose that the indirect effect of radiation may induce DNA damage by cell cycle arrest and receptor mediated apoptotic cascade which lead to apoptotic death of neuronal SH-SY5Y cells. We also hypothesized that coculture (with glial U87) may relieved the neuronal SH-SY5Y cells from toxicity of indirect effects radiation by reducing DNA damage and expression of apoptotic proteins in vitro. In the present study irradiated cell conditioned medium (ICCM) was used as source of indirect effect of radiation. Neuronal SH-SY5Y cells were exposed to ICCM with and without coculture with (glial U87) in transwell coculture system respectively. Various endpoints such as, cell survival number assay, Annexin V/PI assay, cell cycle analysis by flow cytometer, mRNA level of Fas receptor by q RT-PCR, expression of key apoptotic proteins by western blot and estimation of neurotrophic factors by ELISA method were analyzed into neuronal SH-SY5Y cells with and without co culture after ICCM exposure respectively. We found that ICCM induced DNA damage in neuronal SH-SY5Y cells by significant increase in cell cycle arrest at S-phase (***P < 0.001) which was further supported by over expression of P53 protein (**P < 0.01). While coculture (with glial U87), significantly reduced the ICCM induced cell cycle arrest and expression of P53 ((###) P < 0.001) neuronal SH-SY5Y cells. Further investigation of the underlying apoptotic mechanism revealed that in coculture system; ICCM induced elevated level of FAS mRNA level was significantly reduced

  2. The Effect of Acute Microgravity on Mechanically-Induced Membrane Damage and Membrane-Membrane Fusion Events

    NASA Technical Reports Server (NTRS)

    Clarke, Mark, S. F.; Vanderburg, Charles R.; Feedback, Daniel L.

    2001-01-01

    Although it is unclear how a living cell senses gravitational forces there is no doubt that perturbation of the gravitational environment results in profound alterations in cellular function. In the present study, we have focused our attention on how acute microgravity exposure during parabolic flight affects the skeletal muscle cell plasma membrane (i.e. sarcolemma), with specific reference to a mechanically-reactive signaling mechanism known as mechanically-induced membrane disruption or "wounding". This response is characterized by both membrane rupture and membrane resealing events mediated by membrane-membrane fusion. We here present experimental evidence that acute microgravity exposure can inhibit membrane-membrane fusion events essential for the resealing of sarcolemmal wounds in individual human myoblasts. Additional evidence to support this contention comes from experimental studies that demonstrate acute microgravity exposure also inhibits secretagogue-stimulated intracellular vesicle fusion with the plasma membrane in HL-60 cells. Based on our own observations and those of other investigators in a variety of ground-based models of membrane wounding and membrane-membrane fusion, we suggest that the disruption in the membrane resealing process observed during acute microgravity is consistent with a microgravity-induced decrease in membrane order.

  3. The effect of acute microgravity on mechanically-induced membrane damage and membrane-membrane fusion events

    NASA Technical Reports Server (NTRS)

    Clarke, M. S.; Vanderburg, C. R.; Feeback, D. L.; McIntire, L. V. (Principal Investigator)

    2001-01-01

    Although it is unclear how a living cell senses gravitational forces there is no doubt that perturbation of the gravitational environment results in profound alterations in cellular function. In the present study, we have focused our attention on how acute microgravity exposure during parabolic flight affects the skeletal muscle cell plasma membrane (i.e. sarcolemma), with specific reference to a mechanically-reactive signaling mechanism known as mechanically-induced membrane disruption or "wounding". Both membrane rupture and membrane resealing events mediated by membrane-membrane fusion characterize this response. We here present experimental evidence that acute microgravity exposure can inhibit membrane-membrane fusion events essential for the resealing of sarcolemmal wounds in individual human myoblasts. Additional evidence to support this contention comes from experimental studies that demonstrate acute microgravity exposure also inhibits secretagogue-stimulated intracellular vesicle fusion with the plasma membrane in HL-60 cells. Based on our own observations and those of other investigators in a variety of ground-based models of membrane wounding and membrane-membrane fusion, we suggest that the disruption in the membrane resealing process observed during acute microgravity is consistent with a microgravity-induced decrease in membrane order.

  4. The Different Effects of BMI and WC on Organ Damage in Patients from a Cardiac Rehabilitation Program after Acute Coronary Syndrome

    PubMed Central

    Xu, Lin; Zhao, Hui; Qiu, Jian; Zhu, Wei; Lei, Hongqiang; Cai, Zekun; Lin, Wan-Hua; Huang, Wenhua; Zhang, Heye; Zhang, Yuan-Ting

    2015-01-01

    One of the purposes of cardiac rehabilitation (CR) after acute coronary syndrome (ACS) is to monitor and control weight of the patient. Our study is to compare the different obesity indexes, body mass index (BMI), and waist circumference (WC), through one well-designed CR program (CRP) with ACS in Guangzhou city of Guangdong Province, China, in order to identify different effects of BMI and WC on organ damage. In our work, sixty-one patients between October 2013 and January 2014 fulfilled our study. We collected the vital signs by medical records, the clinical variables of body-metabolic status by fasting blood test, and the organ damage variables by submaximal exercise treadmill test (ETT) and ultrasonic cardiogram (UCG) both on our inpatient and four-to-five weeks of outpatient part of CRP after ACS. We mainly used two-tailed Pearson's test and liner regression to evaluate the relationship of BMI/WC and organ damage. Our results confirmed that WC could be more accurate than BMI to evaluate the cardiac function through the changes of left ventricular structure on the CRP after ACS cases. It makes sense of early diagnosis, valid evaluation, and proper adjustment to ACS in CRP of the obesity individuals in the future. PMID:26247035

  5. N-Acetylaspartate, a marker of both cellular dysfunction and neuronal loss: its relevance to studies of acute brain injury.

    PubMed

    Demougeot, C; Garnier, P; Mossiat, C; Bertrand, N; Giroud, M; Beley, A; Marie, C

    2001-04-01

    To evaluate the contribution of cellular dysfunction and neuronal loss to brain N-acetylaspartate (NAA) depletion, NAA was measured in brain tissue by HPLC and UV detection in rats subjected to cerebral injury, associated or not with cell death. When lesion was induced by intracarotid injection of microspheres, the fall in NAA was related to the degree of embolization and to the severity of brain oedema. When striatal lesion was induced by local injection of malonate, the larger the lesion volume, the higher the NAA depletion. However, reduction of brain oedema and striatal lesion by treatment with the lipophilic iron chelator dipyridyl (20 mg/kg, 1 h before and every 8 h after embolization) and the inducible nitric oxide synthase inhibitor aminoguanidine (100 mg/kg given 1 h before malonate and then every 9 h), respectively, failed to ameliorate the fall in NAA. Moreover, after systemic administration of 3-nitropropionic acid, a marked reversible fall in NAA striatal content was observed despite the lack of tissue necrosis. Overall results show that cellular dysfunction can cause higher reductions in NAA level than neuronal loss, thus making of NAA quantification a potential tool for visualizing the penumbra area in stroke patients.

  6. Crystal amphetamine smoking-induced acute eosinophilic pneumonia and diffuse alveolar damage: a case report and literature review.

    PubMed

    Lin, Shih-Sen; Chen, Yu-Ching; Chang, Yih-Leong; Yeh, Diana Yu-Wung; Lin, Chen-Chun

    2014-10-31

    Eosinophilic pneumonia (EP) is a disease characterized by prominent infiltration of lung structures by eosinophils. The lung interstitium is infiltrated by eosinophils, and essentially the alveolar spaces are filled with eosinophils and a fibrinous exudate, with conservation of the global architecture of the lung. Diagnosis of EP relies on pathological demonstration of alveolar eosinophilia along with characteristic clinical manifestations of nonproductive cough, dyspnea, chest pain and/or unique imaging features. EP may be categorized according to the origin: EP of undetermined origin may overlap with well-individualized syndromes, while EP with a definite cause are mainly due to infections or drug abuse. Here, we report a case of an amphetamine abuser who developed acute EP and acute respiratory distress syndrome after amphetamine inhalation. Related studies on the pathogenesis of stimulant-related lung injury and treatment strategies are also discussed.

  7. Heme Oxygenase-1 Protects Neurons from Ischemic Damage by Upregulating Expression of Cu,Zn-Superoxide Dismutase, Catalase, and Brain-Derived Neurotrophic Factor in the Rabbit Spinal Cord.

    PubMed

    Jung, Hyo Young; Kim, Dae Won; Yim, Hee Sun; Yoo, Dae Young; Kim, Jong Whi; Won, Moo-Ho; Yoon, Yeo Sung; Choi, Soo Young; Hwang, In Koo

    2016-04-01

    In the present study, we investigated the protective effects of heme oxygenase (HO-1) against ischemic damage in motor neurons of the rabbit spinal cord. A PEP-1-HO-1 fusion protein was made to and confirmed the effective the penetration of HO-1 into spinal cord neurons at 8 h after treatment. Transient spinal cord ischemia was induced by occlusion of the abdominal aorta for 15 min. Vehicle (glycerol) or 0.375 mg/kg PEP-1-HO-1 was administered intraperitoneally to rabbits immediately after ischemia/reperfusion. Animals were sacrificed 15 min after reperfusion to measure lactate levels; 24 h after reperfusion to measure caspase 3 and myeloperoxidase levels, lipid peroxidation, and the activity of Cu,Zn-superoxide dismutase (SOD1) and catalase (CAT); or 72 h after reperfusion to assess neuronal survival and measure the levels of brain-derived neurotrophic factor (BDNF) in spinal cord homogenates. Administration of PEP-1-HO-1 did not significantly alter arterial blood gases (PaCO2 and PaO2), pH, or blood glucose levels before ischemia, 10 min after occlusion, or 10 min after reperfusion. Mean arterial pressure was selectively reduced 10 min after occlusion. Administration of PEP-1-HO-1 improved the rabbit Tarlov scores, and increased neuronal survival, as assessed by NeuN immunohistochemical staining 72 h after ischemia/reperfusion. In addition, administration of PEP-1-HO-1 significantly ameliorated lactate accumulation 15 min after reperfusion, and the increases in caspase 3, myeloperoxidase, and lipid peroxidation 24 h after reperfusion. PEP-1-HO-1 administration significantly mitigated the decrease in SOD1 and CAT 24 h after reperfusion, and reversed the decrease in BDNF levels in spinal cord homogenates 72 h after ischemia/reperfusion. These results suggest that PEP-1-HO-1 can protect against neuronal damage after transient spinal cord ischemia by limiting early lactic acidosis and increasing SOD1, CAT, and BDNF levels.

  8. Processing of cdk5 activator p35 to its truncated form (p25) by calpain in acutely injured neuronal cells.

    PubMed

    Nath, R; Davis, M; Probert, A W; Kupina, N C; Ren, X; Schielke, G P; Wang, K K

    2000-07-21

    Recently, it was shown that conversion of cdk5 activator protein p35 to a C-terminal fragment p25 promotes a deregulation of cdk5 activity, which may contribute to neurodegeneration in Alzheimer's disease. In this study, we present evidence that calpain is a protease involved in the conversion of p35 to p25. To activate calpain, rat cerebellar granule neurons were treated with maitotoxin (MTX). A C-terminus-directed anti-p35 antibody detected that p35 conversion to p25 paralleled the formation of calpain-generated alpha-spectrin (alpha-fodrin) breakdown products (SBDP's) in a maitotoxin-dose-dependent manner. Two calpain inhibitors (MDl28170 and SJA6017) reduced p35 processing but were unchanged when exposed to the caspase inhibitor carbobenzoxy-Asp-CH(2)OC(=O)-2, 6-dichlorobenzene or the proteasome inhibitors (lactacystin and Z-Ile-Glu(OtBu)Ala-Leu-CHO). p35 protein was also degraded to p25 when rat brain lysate was subjected to in vitro digestion with purified mu- and m-calpains. Additionally, in a rat temporary middle cerebral artery occlusion model, p35 processing to p25 again paralleled SBDP formation in the ischemic core. Lastly, in malonate-injured rat brains, the ipsilateral side showed a striking correlation of SBDP formation with p35 to p25 conversion and tau phosphorylation (at Ser202 and Thr205) increase. These data suggest that calpain is a major neuronal protease capable of converting p35 to p25 and might play a pathological role of activating cdk5 and its phosphorylation of tau in Alzheimer's disease.