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Meyers KT, Damphousse CC, Ozols AB, Campbell JM, Newbern JM, Hu C, Marrone DF, Gallitano AL. Serial electroconvulsive Seizure alters dendritic complexity and promotes cellular proliferation in the mouse dentate gyrus; a role for Egr3. Brain Stimul 2023; 16:889-900. [PMID: 37146791 PMCID: PMC10776161 DOI: 10.1016/j.brs.2023.04.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 04/19/2023] [Accepted: 04/25/2023] [Indexed: 05/07/2023] Open
Abstract
BACKGROUND Despite being one of the safest, most effective treatments for severe mood disorders, the therapeutic mechanisms of electroconvulsive therapy remain unknown. Electroconvulsive seizure (ECS) induces rapid, high-level expression of immediate early genes (IEGs) and brain-derived neurotrophic factor (BDNF), in addition to stimulation of neurogenesis and dendritic remodeling of dentate gyrus (DG) neurons. We have previously shown that this upregulation of BDNF fails to occur in the hippocampus of mice lacking the IEG Egr3. Since BDNF influences neurogenesis and dendritic remodeling, we hypothesized that Egr3-/- mice will exhibit deficits in neurogenesis and dendritic remodeling in response to ECS. OBJECTIVE To test this hypothesis, we examined dendritic remodeling and cellular proliferation in the DG of Egr3-/- and wild-type mice following repeated ECS. METHODS Mice received 10 daily ECSs. Dendritic morphology was examined in Golgi-Cox-stained tissue and cellular proliferation was analyzed through bromodeoxyuridine (BrdU) immunohistochemistry and confocal imaging. RESULTS Serial ECS in mice results in dendritic remodeling, increased spine density, and cellular proliferation in the DG. Loss of Egr3 alters the dendritic remodeling induced by serial ECS but does not change the number of dendritic spines or cellular proliferation consequences of ECS. CONCLUSION Egr3 influences the dendritic remodeling induced by ECS but is not required for ECS-induced proliferation of hippocampal DG cells.
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Affiliation(s)
- K T Meyers
- Interdisciplinary Graduate Program in Neuroscience, Arizona State University, Tempe, AZ, 85281, USA; Basic Medical Sciences, University of Arizona College of Medicine - Phoenix, Phoenix, AZ, 85004, USA
| | - C C Damphousse
- Psychology, Wilfrid Laurier University, Waterloo, ON, N2L 3C5, Canada
| | - A B Ozols
- Basic Medical Sciences, University of Arizona College of Medicine - Phoenix, Phoenix, AZ, 85004, USA
| | - J M Campbell
- Basic Medical Sciences, University of Arizona College of Medicine - Phoenix, Phoenix, AZ, 85004, USA
| | - J M Newbern
- School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA
| | - C Hu
- Epidemiology and Biostatistics, University of Arizona Mel and Enid Zuckerman College of Public Health - Phoenix, 714 E Van Buren St #119, Phoenix, AZ, 85006, USA
| | - D F Marrone
- Psychology, Wilfrid Laurier University, Waterloo, ON, N2L 3C5, Canada.
| | - A L Gallitano
- Basic Medical Sciences, University of Arizona College of Medicine - Phoenix, Phoenix, AZ, 85004, USA.
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Both physiology and epidemiology support zero tolerable blood lead levels. Toxicol Lett 2017; 280:232-237. [DOI: 10.1016/j.toxlet.2017.08.015] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2017] [Revised: 07/17/2017] [Accepted: 08/14/2017] [Indexed: 11/24/2022]
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3
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Song Y, Cheng X, Yang X, Zhao R, Wang P, Han Y, Luo Z, Cao Y, Zhu C, Xiong Y, Liu Y, Wu K, Wu J. Early growth response-1 facilitates enterovirus 71 replication by direct binding to the viral genome RNA. Int J Biochem Cell Biol 2015; 62:36-46. [PMID: 25724735 DOI: 10.1016/j.biocel.2015.02.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 02/05/2015] [Accepted: 02/17/2015] [Indexed: 01/14/2023]
Abstract
Enterovirus 71 (EV71) infections can cause hand, foot and mouth disease (HFMD), meningoencephalitis, neonatal sepsis, and even fatal encephalitis in children. Unfortunately, there is currently no effective treatment for EV71 infection due to the lack of understanding of viral replication and infection; and viral infections have emerged as an imperative global hazard. Thus, it is extremely important to understand the mechanism of EV71 replication in order to prevent and control the diseases associated with EV71 infections. Early growth response-1 (EGR1) is a multifunctional transcription factor that regulates diverse biological functions, including inflammation, apoptosis, differentiation, tumorigenesis, and even viral infection. Here, we provide new insight into the role of EV71 infection in regulating EGR1 production; and reveal a novel mechanism by which EGR1 facilitates EV71 replication. We demonstrate that EV71 activates EGR1 expression during infection by stimulating the protein kinase A/protein kinase Cɛ/phosphoinositide 3-kinase/Akt (PKA/PKCɛ/PI3K/Akt) cascade. We further reveal that EV71-activated EGR1, in turn, regulates the internal ribosomal entry site (IRES) of EV71 to enhance viral replication. In addition, EGR1 facilitates EV71 replication by binding directly to stem-loops I and IV of EV71 5'-untranslated region (5'UTR) with its first two zinc fingers. Moreover, EGR1 protein co-localizes with EV71 RNA in the cytoplasm of infected cells to facilitate viral replication. Our results reveal an important new role of EGR1 in viral infection, provide new insight into the novel mechanism underlying the regulation of EV71 replication, and suggest a potential application of EGR1 in the control of EV71 infection.
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Affiliation(s)
- Yu Song
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Xin Cheng
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Xiaoxia Yang
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Rong Zhao
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Peili Wang
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Yang Han
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Zhen Luo
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Yanhua Cao
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Chengliang Zhu
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Ying Xiong
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Yingle Liu
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Kailang Wu
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Jianguo Wu
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan 430072, China.
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Abstract
Human exposure to neurotoxic metals is a global public health problem. Metals which cause neurological toxicity, such as lead (Pb) and manganese (Mn), are of particular concern due to the long-lasting and possibly irreversible nature of their effects. Pb exposure in childhood can result in cognitive and behavioural deficits in children. These effects are long-lasting and persist into adulthood even after Pb exposure has been reduced or eliminated. While Mn is an essential element of the human diet and serves many cellular functions in the human body, elevated Mn levels can result in a Parkinson's disease (PD)-like syndrome and developmental Mn exposure can adversely affect childhood neurological development. Due to the ubiquitous presence of both metals, reducing human exposure to toxic levels of Mn and Pb remains a world-wide public health challenge. In this review we summarize the toxicokinetics of Pb and Mn, describe their neurotoxic mechanisms, and discuss common themes in their neurotoxicity.
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Affiliation(s)
| | - Tomas R Guilarte
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY 10032, USA.
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Importance of associative learning processes for one-trial behavioral sensitization of preweanling rats. Behav Pharmacol 2012; 22:693-702. [PMID: 21897205 DOI: 10.1097/fbp.0b013e32834affb2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
During adulthood, associative learning is necessary for the expression of one-trial behavioral sensitization; however, it is uncertain whether the same associative processes are operative during the preweanling period. Two strategies were used to assess the importance of associative learning for one-trial behavioral sensitization of preweanling rats. In the initial experiments, we varied both the sequence and time interval between presentation of the conditioned stimulus (CS, novel environment) and unconditioned stimulus (US, cocaine). In the final experiment, we determined whether electroconvulsive shock-induced retrograde amnesia would disrupt one-trial behavioral sensitization. Results showed that robust-sensitized responding was apparent regardless of the sequence in which cocaine and the novel environment (the presumptive CS) were presented. Varying the time between CS and US presentation (0, 3, or 6 h) was also without effect. Results from experiment 3 showed that single or multiple electroconvulsive shock treatments did not alter the expression of the sensitized response. Therefore, these data indicated that one-trial behavioral sensitization of preweanling rats was exclusively mediated by nonassociative mechanisms and that associative processes did not modulate sensitized responding. These findings are in contrast to what is observed during adulthood, as adult rats exhibit one-trial behavioral sensitization only when associative processes are operative.
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Molecular neurobiology of lead (Pb(2+)): effects on synaptic function. Mol Neurobiol 2010; 42:151-60. [PMID: 21042954 DOI: 10.1007/s12035-010-8146-0] [Citation(s) in RCA: 137] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Accepted: 10/13/2010] [Indexed: 12/16/2022]
Abstract
Lead (Pb(2+)) is a ubiquitous environmental neurotoxicant that continues to threaten public health on a global scale. Epidemiological studies have demonstrated detrimental effects of Pb(2+) on childhood IQ at very low levels of exposure. Recently, a mechanistic understanding of how Pb(2+) affects brain development has begun to emerge. The cognitive effects of Pb(2+) exposure are believed to be mediated through its selective inhibition of the N-methyl-D: -aspartate receptor (NMDAR). Studies in animal models of developmental Pb(2+) exposure exhibit altered NMDAR subunit ontogeny and disruption of NMDAR-dependent intracellular signaling. Additional studies have reported that Pb(2+) exposure inhibits presynaptic calcium (Ca(2+)) channels and affects presynaptic neurotransmission, but a mechanistic link between presynaptic and postsynaptic effects has been missing. Recent work has suggested that the presynaptic and postsynaptic effects of Pb(2+) exposure are both due to inhibition of the NMDAR by Pb(2+), and that the presynaptic effects of Pb(2+) may be mediated by disruption of NMDAR activity-dependent signaling of brain-derived neurotrophic factor (BDNF). These findings provide the basis for the first working model to describe the effects of Pb(2+) exposure on synaptic function. Here, we review the neurotoxic effects of Pb(2+) exposure and discuss the known effects of Pb(2+) exposure in light of these recent findings.
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Kim SH, Kim MK, Yu HS, Kim HS, Park IS, Park HG, Kang UG, Kim YS. Electroconvulsive seizure increases phosphorylation of PKC substrates, including GAP-43, MARCKS, and neurogranin, in rat brain. Prog Neuropsychopharmacol Biol Psychiatry 2010; 34:115-21. [PMID: 19837121 DOI: 10.1016/j.pnpbp.2009.10.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2009] [Revised: 10/08/2009] [Accepted: 10/08/2009] [Indexed: 01/06/2023]
Abstract
Protein kinase C (PKC) has been suggested as a molecular target related to the pathogenetic and therapeutic mechanisms of mood disorders in which electroconvulsive seizure (ECS) is effective. However, the reports concerning the effects of ECS on PKC are anecdotal and need further clarification. In this study, we examined the effects of ECS treatment on the phosphorylation of PKC substrates, including GAP-43, MARCKS, and neurogranin. Immunoblot using anti-p-PKC substrate antibodies revealed that a single ECS treatment induced temporal changes in the phosphorylation level of PKC substrates in rat brain, reflecting the effects on PKC activity. Phosphorylation of GAP-43 and MARCKS, representative PKC substrates related to synaptic remodeling, increased from 5 to 30 min, after a transient decrease at 0 min immediately after ECS, and returned to basal levels at 60 min in rat frontal cortex, hippocampus, and cerebellum. Phosphorylation of neurogranin, another PKC substrate, showed a similar pattern of temporal changes in the frontal cortex and hippocampus. Immunohistochemical analysis revealed that p-GAP-43 and p-MARCKS were densely stained throughout the neuronal cells of the prefrontal cortex and hippocampus, and the Purkinje cells of cerebellum, after ECS treatment. Brief and transient activation of PKC may be translated into long-term biochemical changes, resulting in synaptic plasticity. Taken together, the acute effects of ECS on PKC activity, which could be an underpinning of long-term biochemical changes induced by ECS, may contribute to understand the molecular mechanism of ECS.
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Affiliation(s)
- Se Hyun Kim
- Department of Psychiatry and Behavioral Science and Institute of Human Behavioral Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
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Verstraeten SV, Aimo L, Oteiza PI. Aluminium and lead: molecular mechanisms of brain toxicity. Arch Toxicol 2008; 82:789-802. [DOI: 10.1007/s00204-008-0345-3] [Citation(s) in RCA: 333] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2008] [Accepted: 07/15/2008] [Indexed: 10/21/2022]
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Huang Y, Man HY, Sekine-Aizawa Y, Han Y, Juluri K, Luo H, Cheah J, Lowenstein C, Huganir RL, Snyder SH. S-nitrosylation of N-ethylmaleimide sensitive factor mediates surface expression of AMPA receptors. Neuron 2005; 46:533-40. [PMID: 15944123 DOI: 10.1016/j.neuron.2005.03.028] [Citation(s) in RCA: 139] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2004] [Revised: 01/12/2005] [Accepted: 03/24/2005] [Indexed: 10/25/2022]
Abstract
Postsynaptic AMPA receptor (AMPAR) trafficking mediates some forms of synaptic plasticity that are modulated by NMDA receptor (NMDAR) activation and N-ethylmaleimide sensitive factor (NSF). We report that NSF is physiologically S-nitrosylated by endogenous, neuronally derived nitric oxide (NO). S-nitrosylation of NSF augments its binding to the AMPAR GluR2 subunit. Surface insertion of GluR2 in response to activation of synaptic NMDARs requires endogenous NO, acting selectively upon the binding of NSF to GluR2. Thus, AMPAR recycling elicited by NMDA neurotransmission is mediated by a cascade involving NMDA activation of neuronal NO synthase to form NO, leading to S-nitrosylation of NSF which is thereby activated, enabling it to bind to GluR2 and promote the receptor's surface expression.
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Affiliation(s)
- Yunfei Huang
- Department of Neuroscience, Johns Hopkins University, School of Medicine, 725 North Wolfe Street, Baltimore, Maryland 21205, USA
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Abstract
Clinical disorders of brain plasticity are common in the practice of child neurology. Children have an enhanced capacity for brain plasticity compared to adults as demonstrated by their superior ability to learn a second language or their capacity to recover from brain injuries or radical surgery such as hemispherectomy for epilepsy. Basic mechanisms that support plasticity during development include persistence of neurogenesis in some parts of the brain, elimination of neurons through apoptosis or programmed cell death, postnatal proliferation and pruning of synapses, and activity-dependent refinement of neuronal connections. Brain plasticity in children can be divided into four types: adaptive plasticity that enhances skill development or recovery from brain injury; impaired plasticity associated with cognitive impairment; excessive plasticity leading to maladaptive brain circuits; and plasticity that becomes the brain's 'Achilles' Heel' because makes it vulnerable to injury. A broad group of pediatric neurologic disorders can be understood in terms of their impact on fundamental mechanisms for brain plasticity. These include neurofibromatosis, tuberous sclerosis, Fragile X syndrome, other inherited forms of mental retardation, cretinism, Coffin-Lowry syndrome, lead poisoning, Rett syndrome, epilepsy, hypoxic-ischemic encephalopathy and cerebral palsy.
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Affiliation(s)
- Michael V Johnston
- Department of Neurology and Developmental Medicine, Kennedy Krieger Institute, Johns Hopkins University School of Medicine, 707 North Broadway, Baltimore, MD 21205, USA.
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11
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Olivi L, Sisk J, Bressler J. The involvement of lipid activators of protein kinase C in the induction of ZIF268 in PC12 cells exposed to lead. Neurochem Res 2003; 28:65-71. [PMID: 12587664 DOI: 10.1023/a:1021696011920] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Lead (Pb) induces the expression of immediate early genes (IEG) in PC12 cells by a mechanism that involves protein kinase C (PKC). To define the mechanisms, the involvement of two commonly observed lipid activators of PKC, diacylglycerols, and phosphatidylinositols, were examined. A dose-dependent increase in the expression of the IEG zif268 was observed in PC12 cells exposed to Pb. The PKC inhibitor Ro-31-8220 blocked the induction. An increase in levels of diacylglycerols was observed in PC12 cells exposed to Pb, but the increase was inhibited by Ro-31-8220. The phosphatidylinositol 3-kinase inhibitor Wortmannin, but not the inhibitor LY 294002, blocked the induction zif268 in Pb-exposed cells. Small increases in phosphatidylinositol 3-kinase activity were observed after exposure to Pb. In summary, diacylglycerols are elevated in PC12 cells exposed to Pb by a mechanism that requires PKC. It is possible that diacylglycerols contribute to the induction of zif268 by Pb by sustaining PKC activation.
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Affiliation(s)
- Luisa Olivi
- Kennedy Krieger Research Institute, Baltimore, Maryland 21205, USA
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12
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Abstract
Plasticity includes the brain's capacity to be shaped or moulded by experience, the capacity to learn and remember, and the ability to reorganize and recover after injury. Mechanisms for plasticity include activity-dependent refinement of neuronal connections and synaptic plasticity as a substrate for learning and memory. The molecular mechanisms for these processes utilize signalling cascades that relay messages from synaptic receptors to the nucleus and the cytoskeleton to control the structure of axons and dendrites. Several paediatric neurological disorders such as neurofibromatosis-1, Fragile X syndrome, Rett syndrome, and other syndromic and non-specific forms of mental retardation involve lesions in these signalling pathways. Acquired disorders such as hypoxic-ischaemic encephalopathy, lead poisoning and epilepsy also involve signalling pathways including excitatory glutamate receptors. Information about these 'plasticity pathways' is useful for understanding their pathophysiology and potential therapy.
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Affiliation(s)
- Michael V Johnston
- Department of Neurology and Developmental Medicine, Kennedy Krieger Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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13
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Abstract
The detrimental effects of lead poisoning have been well known since ancient times, but some of the most severe consequences of exposure to this metal have only been described recently. Lead [Pb(II)] affects the higher functions of the central nervous system and undermines brain growth, preventing the correct development of cognitive and behavioral functions. As an established neurotoxin, Pb(II) crosses the blood-brain barrier rapidly and concentrates in the brain. The mechanisms of lead neurotoxicity are complex and still not fully understood, but recent findings recognized that both Ca(II) dependent proteins and neurotransmitters receptors represent significant targets for Pb(II). In particular, acute and chronic exposure to lead would predominantly affect two specific protein complexes: protein kinase C and the N-methyl-D-aspartate subtype of glutamate receptor. These protein complexes are deeply involved in learning and cognitive functions and are also thought to interact significantly with each other to mediate these functions. This review outlines the most recent hypotheses and evidences that link lead poisoning to impairment of these protein functions, as well as the in vitro experimental approaches that are most likely to provide information on basic mechanicistic processes.
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Affiliation(s)
- Carla Marchetti
- Istituto di Biofisica, Sezione di Genova, Consiglio Nazionale delle Ricerche, via De Marini, 6 - 16149 Genova, Italy.
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