scholarly journals Experimental Pneumococcal Meningitis: Impaired Clearance of Bacteria from the Blood Due to Increased Apoptosis in the Spleen in Bcl-2-Deficient Mice

2004 ◽  
Vol 72 (6) ◽  
pp. 3113-3119 ◽  
Author(s):  
Andreas Wellmer ◽  
Matthias von Mering ◽  
Annette Spreer ◽  
Ricarda Diem ◽  
Helmut Eiffert ◽  
...  
Keyword(s):  
Pneumococcal Meningitis ◽  
Neuronal Damage ◽  
Hippocampal Formation ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Clinical Score ◽  
Tight Rope ◽  
Induced Apoptosis ◽  
The Brain ◽  
Deficient Mice

ABSTRACT Necrotic and apoptotic neuronal cell death can be found in pneumococcal meningitis. We investigated the role of Bcl-2 as an antiapoptotic gene product in pneumococcal meningitis using Bcl-2 knockout (Bcl-2−/−) mice. By using a model of pneumococcal meningitis induced by intracerebral infection, Bcl-2-deficient mice and control littermates were assessed by clinical score and a tight rope test at 0, 12, 24, 32, and 36 h after infection. Then mice were sacrificed, the bacterial titers in blood, spleen, and cerebellar homogenates were determined, and the brain and spleen were evaluated histologically. The Bcl-2-deficient mice developed more severe clinical illness, and there were significant differences in the clinical score at 24, 32, and 36 h and in the tight rope test at 12 and 32 h. The bacterial titers in the blood were greater in Bcl-2-deficient mice than in the controls (7.46 ± 1.93 log CFU/ml versus 5.16 ± 0.96 log CFU/ml [mean ± standard deviation]; P < 0.01). Neuronal damage was most prominent in the hippocampal formation, but there were no significant differences between groups. In situ tailing revealed only a few apoptotic neurons in the brain. In the spleen, however, there were significantly more apoptotic leukocytes in Bcl-2-deficient mice than in controls (5,148 ± 3,406 leukocytes/mm2 versus 1,070 ± 395 leukocytes/mm2; P < 0.005). Bcl-2 appears to counteract sepsis-induced apoptosis of splenic lymphocytes, thereby enhancing clearance of bacteria from the blood.

scholarly journals Peroxiredoxin II Maintains the Mitochondrial Membrane Potential against Alcohol-Induced Apoptosis in HT22 Cells

Antioxidants ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 1
Author(s):  
Mei-Hua Jin ◽  
Jia-Bin Yu ◽  
Hu-Nan Sun ◽  
Ying-Hua Jin ◽  
Gui-Nan Shen ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Ht22 Cells ◽  
Apoptotic Protein ◽  
Intracellular Ros ◽  
Induced Apoptosis ◽  
The Brain

Excessive alcohol intake can significantly reduce cognitive function and cause irreversible learning and memory disorders. The brain is particularly vulnerable to alcohol-induced ROS damage; the hippocampus is one of the most sensitive areas of the brain for alcohol neurotoxicity. In the present study, we observed significant increasing of intracellular ROS accumulations in Peroxiredoxin II (Prx II) knockdown HT22 cells, which were induced by alcohol treatments. We also found that the level of ROS in mitochondrial was also increased, resulting in a decrease in the mitochondrial membrane potential. The phosphorylation of GSK3β (Ser9) and anti-apoptotic protein Bcl2 expression levels were significantly downregulated in Prx II knockdown HT22 cells, which suggests that Prx II knockdown HT22 cells were more susceptible to alcohol-induced apoptosis. Scavenging the alcohol-induced ROS with NAC significantly decreased the intracellular ROS levels, as well as the phosphorylation level of GSK3β in Prx II knockdown HT22 cells. Moreover, NAC treatment also dramatically restored the mitochondrial membrane potential and the cellular apoptosis in Prx II knockdown HT22 cells. Our findings suggest that Prx II plays a crucial role in alcohol-induced neuronal cell apoptosis by regulating the cellular ROS levels, especially through regulating the ROS-dependent mitochondrial membrane potential. Consequently, Prx II may be a therapeutic target molecule for alcohol-induced neuronal cell death, which is closely related to ROS-dependent mitochondria dysfunction.

scholarly journals Neuroprotective Effect of Antioxidants in the Brain

2020 ◽  
Vol 21 (19) ◽  
pp. 7152 ◽  
Author(s):  
Kyung Hee Lee ◽  
Myeounghoon Cha ◽  
Bae Hwan Lee
Keyword(s):  
Oxidative Stress ◽  
Neurodegenerative Diseases ◽  
Intracellular Signaling ◽  
Neuronal Damage ◽  
Neuroprotective Effect ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
High Energy ◽  
Antioxidant Compounds ◽  
The Brain

The brain is vulnerable to excessive oxidative insults because of its abundant lipid content, high energy requirements, and weak antioxidant capacity. Reactive oxygen species (ROS) increase susceptibility to neuronal damage and functional deficits, via oxidative changes in the brain in neurodegenerative diseases. Overabundance and abnormal levels of ROS and/or overload of metals are regulated by cellular defense mechanisms, intracellular signaling, and physiological functions of antioxidants in the brain. Single and/or complex antioxidant compounds targeting oxidative stress, redox metals, and neuronal cell death have been evaluated in multiple preclinical and clinical trials as a complementary therapeutic strategy for combating oxidative stress associated with neurodegenerative diseases. Herein, we present a general analysis and overview of various antioxidants and suggest potential courses of antioxidant treatments for the neuroprotection of the brain from oxidative injury. This review focuses on enzymatic and non-enzymatic antioxidant mechanisms in the brain and examines the relative advantages and methodological concerns when assessing antioxidant compounds for the treatment of neurodegenerative disorders.

scholarly journals Neuronal Damage and Neuroinflammation, a Bridge Between Bacterial Meningitis and Neurodegenerative Diseases

2021 ◽  
Vol 15 ◽  
Author(s):  
Kristine Farmen ◽  
Miguel Tofiño-Vian ◽  
Federico Iovino
Keyword(s):  
Bacterial Meningitis ◽  
Neurodegenerative Diseases ◽  
Neuronal Damage ◽  
Bacterial Pathogens ◽  
Neuronal Cell Death ◽  
Bacterial Pathogen ◽  
Neuronal Cell ◽  
Brain Parenchyma ◽  
Bacterial Interaction ◽  
The Brain

Bacterial meningitis is an inflammation of the meninges which covers and protects the brain and the spinal cord. Such inflammation is mostly caused by blood-borne bacteria that cross the blood-brain barrier (BBB) and finally invade the brain parenchyma. Pathogens such as Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae are the main etiological causes of bacterial meningitis. After trafficking across the BBB, bacterial pathogens in the brain interact with neurons, the fundamental units of Central Nervous System, and other types of glial cells. Although the specific molecular mechanism behind the interaction between such pathogens with neurons is still under investigation, it is clear that bacterial interaction with neurons and neuroinflammatory responses within the brain leads to neuronal cell death. Furthermore, clinical studies have shown indications of meningitis-caused dementia; and a variety of neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease and Huntington’s disease are characterized by the loss of neurons, which, unlike many other eukaryotic cells, once dead or damaged, they are seldom replaced. The aim of this review article is to provide an overview of the knowledge on how bacterial pathogens in the brain damage neurons through direct and indirect interactions, and how the neuronal damage caused by bacterial pathogen can, in the long-term, influence the onset of neurodegenerative disorders.

scholarly journals The formyl peptide receptor agonist Ac2-26 alleviates neuroinflammation in a mouse model of pneumococcal meningitis

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Marvin Rüger ◽  
Eugenia Kipp ◽  
Nadine Schubert ◽  
Nicole Schröder ◽  
Thomas Pufe ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Bacterial Meningitis ◽  
Mouse Model ◽  
Post Infection ◽  
Pneumococcal Meningitis ◽  
Hippocampal Formation ◽  
Formyl Peptide Receptor ◽  
Formyl Peptide ◽  
Anti Inflammatory ◽  
Deficient Mice

Abstract Background Bacterial meningitis is still a cause of severe neurological disability. The brain is protected from penetrating pathogens by the blood-brain barrier and the innate immune system. The invading pathogens are recognized by pattern recognition receptors including the G-protein-coupled formyl peptide receptors (FPRs), which are expressed by immune cells of the central nervous system. FPRs show a broad spectrum of ligands, including pro- and anti-inflammatory ones. Here, we investigated the effects of the annexin A1 mimetic peptide Ac2-26 in a mouse model of pneumococcal meningitis. Methods Wildtype (WT) and Fpr1- and Fpr2-deficient mice were intrathecally infected with Streptococcus pneumoniae D39 (type 2). Subsequently, the different mice groups were treated by intraperitoneal injections of Ac2-26 (1 mg/kg body weight) 2, 8, and 24 h post-infection. The extent of inflammation was analyzed in various brain regions by means of immunohistochemistry and real-time reverse transcription polymerase chain reaction (RT-PCR) 30 h post-infection. Results Ac2-26-treated WT mice showed less severe neutrophil infiltration, paralleled by a reduced induction of pro-inflammatory glial cell responses in the hippocampal formation and cortex. While meningitis was ameliorated in Ac2-26-treated Fpr1-deficient mice, this protective effect was not observed in Fpr2-deficient mice. Irrespective of Ac2-26 treatment, inflammation was more severe in Fpr2-deficient compared to Fpr1-deficient mice. Conclusions In summary, this study demonstrates anti-inflammatory properties of Ac2-26 in a model of bacterial meningitis, which are mediated via FPR2, but not FPR1. Ac2-26 and other FPR2 modulators might be promising targets for the development of novel therapies for Streptococcus pneumoniae-induced meningitis.

scholarly journals TNFα-induced AMPA-receptor trafficking in CNS neurons; relevance to excitotoxicity?

2004 ◽  
Vol 1 (3) ◽  
pp. 263-273 ◽  
Author(s):  
DMITRI LEONOUDAKIS ◽  
STEVEN P. BRAITHWAITE ◽  
MICHAEL S. BEATTIE ◽  
ERIC C. BEATTIE
Keyword(s):  
Cell Death ◽  
Inflammatory Response ◽  
Hippocampal Neurons ◽  
Neuronal Damage ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Cell Types ◽  
Synaptic Function ◽  
Ampar Trafficking ◽  
Novel Target

Injury and disease in the CNS increases the amount of tumor necrosis factor α (TNFα) that neurons are exposed to. This cytokine is central to the inflammatory response that occurs after injury and during prolonged CNS disease, and contributes to the process of neuronal cell death. Previous studies have addressed how long-term apoptotic-signaling pathways that are initiated by TNFα might influence these processes, but the effects of inflammation on neurons and synaptic function in the timescale of minutes after exposure are largely unexplored. Our published studies examining the effect of TNFα on trafficking of AMPA-type glutamate receptors (AMPARs) in hippocampal neurons demonstrate that glial-derived TNFα causes a rapid (<15 minute) increase in the number of neuronal, surface-localized, synaptic AMPARs leading to an increase in synaptic strength. This indicates that TNFα-signal transduction acts to facilitate increased surface localization of AMPARs from internal postsynaptic stores. Importantly, an excess of surface localized AMPARs might predispose the neuron to glutamate-mediated excitotoxicity and excessive intracellular calcium concentrations, leading to cell death. This suggests a new mechanism for excitotoxic TNFα-induced neuronal death that is initiated minutes after neurons are exposed to the products of the inflammatory response.Here we review the importance of AMPAR trafficking in normal neuronal function and how abnormalities that are mediated by glial-derived cytokines such as TNFα can be central in causing neuronal disorders. We have further investigated the effects of TNFα on different neuronal cell types and present new data from cortical and hippocampal neurons in culture. Finally, we have expanded our investigation of the temporal profile of the action of this cytokine relevant to neuronal damage. We conclude that TNFα-mediated effects on AMPAR trafficking are common in diverse neuronal cell types and very rapid in their onset. The abnormal AMPAR trafficking elicited by TNFα might present a novel target to aid the development of new neuroprotective drugs.

scholarly journals Induction of the Nrf2 Pathway by Sulforaphane Is Neuroprotective in a Rat Temporal Lobe Epilepsy Model

Antioxidants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1702
Author(s):  
Sereen Sandouka ◽  
Tawfeeq Shekh-Ahmad
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Status Epilepticus ◽  
Temporal Lobe Epilepsy ◽  
Antioxidant Capacity ◽  
Temporal Lobe ◽  
Epileptiform Activity ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
The Brain

Epilepsy is a chronic disease of the brain that affects over 65 million people worldwide. Acquired epilepsy is initiated by neurological insults, such as status epilepticus, which can result in the generation of ROS and induction of oxidative stress. Suppressing oxidative stress by upregulation of the transcription factor, nuclear factor erythroid 2-related factor 2 (Nrf2) has been shown to be an effective strategy to increase endogenous antioxidant defences, including in brain diseases, and can ameliorate neuronal damage and seizure occurrence in epilepsy. Here, we aim to test the neuroprotective potential of a naturally occurring Nrf2 activator sulforaphane, in in vitro epileptiform activity model and a temporal lobe epilepsy rat model. Sulforaphane significantly decreased ROS generation during epileptiform activity, restored glutathione levels, and prevented seizure-like activity-induced neuronal cell death. When given to rats after 2 h of kainic acid-induced status epilepticus, sulforaphane significantly increased the expression of Nrf2 and related antioxidant genes, improved oxidative stress markers, and increased the total antioxidant capacity in both the plasma and hippocampus. In addition, sulforaphane significantly decreased status epilepticus-induced neuronal cell death. Our results demonstrate that Nrf2 activation following an insult to the brain exerts a neuroprotective effect by reducing neuronal death, increasing the antioxidant capacity, and thus may also modify epilepsy development.

scholarly journals Neurotoxic Effect of Ethanolic Extract of Propolis in the Presence of Copper Ions is Mediated through Enhanced Production of ROS and Stimulation of Caspase-3/7 Activity

Toxins ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 273 ◽  
Author(s):  
Vedrana Radovanović ◽  
Josipa Vlainić ◽  
Nikolina Hanžić ◽  
Petra Ukić ◽  
Nada Oršolić ◽  
...  
Keyword(s):  
Cell Death ◽  
Caspase 3 ◽  
Neuronal Damage ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Ethanolic Extract ◽  
Mitogen Activated Protein Kinase ◽  
Enhanced Production ◽  
Toxicological Studies ◽  
Ethanolic Extract Of Propolis

Elevated amounts of copper are considered to be contributing factor in the progression of neurodegenerative diseases as they promote oxidative stress conditions. The aim of our study was to examine the effects of ethanolic extract of propolis (EEP) against copper-induced neuronal damage. In cultured P19 neuronal cells, EEP exacerbated copper-provoked neuronal cell death by increasing the generation of reactive oxygen species (ROS) and through the activation of caspase-3/7 activity. EEP augmented copper-induced up-regulation of p53 and Bax mRNA expressions. Neurotoxic effects of EEP were accompanied by a strong induction of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) expression and decrease in the expression of c-fos mRNA. SB203580, an inhibitor of p38 mitogen-activated protein kinase (MAPK) prevented detrimental effects of EEP, whereas SP600125, an inhibitor of c-Jun N-terminal kinase (JNK), exacerbated EEP-induced neuronal cell death. Quercetin, a polyphenolic nutraceutical, which is usually present in propolis, was also able to exacerbate copper-induced neuronal death. Our data indicates a pro-oxidative and apoptotic mode of EEP action in the presence of excess copper, wherein ROS/p53/p38 interactions play an important role in death cascades. Our study also pointed out that detailed pharmacological and toxicological studies must be carried out for propolis and other dietary supplements in order to fully recognize the potential adverse effects in specific conditions.

Alterations in τ Immunostaining in the Rat Hippocampus following Transient Cerebral Ischemia

1994 ◽  
Vol 14 (4) ◽  
pp. 554-564 ◽  
Author(s):  
James W. Geddes ◽  
Claudia Schwab ◽  
Susan Craddock ◽  
Janice L. Wilson ◽  
L. Creed Pettigrew
Keyword(s):  
Neuronal Damage ◽  
Hippocampal Formation ◽  
Molecular Layer ◽  
Neuronal Cell ◽  
Direct Result ◽  
Ischemic Insult ◽  
Vessel Occlusion ◽  
Neuronal Populations ◽  
Neuronal Cell Bodies ◽  
Hilar Neurons

Previous studies in gerbils have shown that cytoskeletal disruption and a loss of the dendritic microtubule-associated protein, MAP2, may occur after short periods of transient global ischemia. τ, a predominantly axonal microtubule-associated protein, has not been examined following ischemia. We compared neuronal damage with alterations in MAP2, τ, and 72-kD heat shock protein (HSP72) immunostaining at various reperfusion times following 20 min of ischemia in the rat four-vessel occlusion model. τ accumulated in neuronal cell bodies throughout the hippocampal formation 30 min to 2 h after the ischemic insult. Perikaryal τ immunostaining was transient in most regions, but persisted in polymorphic hilar neurons. This was accompanied by a loss of immunostaining in the target of many hilar neurons, the inner molecular layer of the dentate gyrus. The same neuronal populations that exhibited increased τ immunostaining of perikarya later displayed an induction of HSP72 immunoreactivity. In contrast, loss of MAP2 immunostaining was not consistently observed before neuronal death and did not correspond to HSP72 induction. The altered τ immunostaining is not the direct result of excitotoxic insult, as intrahippocampal injection of kainic acid did not cause the somal accumulation of τ, but did cause disruption of MAP2 immunostaining. Taken together, the results suggest that the somal accumulation of τ is an early, sensitive, and selective marker of ischemic insult.

scholarly journals Microglial TonEBP mediates LPS-induced inflammation and memory loss as transcriptional cofactor for NF-κB and AP-1

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Gyu Won Jeong ◽  
Hwan Hee Lee ◽  
Whaseon Lee-Kwon ◽  
Hyug Moo Kwon
Keyword(s):  
Microglial Activation ◽  
Neuronal Damage ◽  
Neuronal Cell Death ◽  
Myeloid Cells ◽  
Memory Loss ◽  
Neuronal Cell ◽  
Microglial Cell Line ◽  
Bv2 Cells ◽  
Pro Inflammatory Cytokines

Abstract Background Microglia are brain-resident myeloid cells involved in the innate immune response and a variety of neurodegenerative diseases. In macrophages, TonEBP is a transcriptional cofactor of NF-κB which stimulates the transcription of pro-inflammatory genes in response to LPS. Here, we examined the role of microglial TonEBP. Methods We used microglial cell line, BV2 cells. TonEBP was knocked down using lentiviral transduction of shRNA. In animals, TonEBP was deleted from myeloid cells using a line of mouse with floxed TonEBP. Cerulenin was used to block the NF-κB cofactor function of TonEBP. Results TonEBP deficiency blocked the LPS-induced expression of pro-inflammatory cytokines and enzymes in association with decreased activity of NF-κB in BV2 cells. We found that there was also a decreased activity of AP-1 and that TonEBP was a transcriptional cofactor of AP-1 as well as NF-κB. Interestingly, we found that myeloid-specific TonEBP deletion blocked the LPS-induced microglia activation and subsequent neuronal cell death and memory loss. Cerulenin disrupted the assembly of the TonEBP/NF-κB/AP-1/p300 complex and suppressed the LPS-induced microglial activation and the neuronal damages in animals. Conclusions TonEBP is a key mediator of microglial activation and neuroinflammation relevant to neuronal damage. Cerulenin is an effective blocker of the TonEBP actions.

scholarly journals Inhibition of Oxidative Neurotoxicity and Scopolamine-Induced Memory Impairment by γ-Mangostin: In Vitro and In Vivo Evidence

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Youngmun Lee ◽  
Sunyoung Kim ◽  
Yeonsoo Oh ◽  
Young-Mi Kim ◽  
Young-Won Chin ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Memory Impairment ◽  
Neuronal Damage ◽  
Biological Activities ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Ros Generation ◽  
Garcinia Mangostana

Among a series of xanthones identified from mangosteen, the fruit of Garcinia mangostana L. (Guttifereae), α- and γ-mangostins are known to be major constituents exhibiting diverse biological activities. However, the effects of γ-mangostin on oxidative neurotoxicity and impaired memory are yet to be elucidated. In the present study, the protective effect of γ-mangostin on oxidative stress-induced neuronal cell death and its underlying action mechanism(s) were investigated and compared to that of α-mangostin using primary cultured rat cortical cells. In addition, the effect of orally administered γ-mangostin on scopolamine-induced memory impairment was evaluated in mice. We found that γ-mangostin exhibited prominent protection against H2O2- or xanthine/xanthine oxidase-induced oxidative neuronal death and inhibited reactive oxygen species (ROS) generation triggered by these oxidative insults. In contrast, α-mangostin had no effects on the oxidative neuronal damage or associated ROS production. We also found that γ-mangostin, not α-mangostin, significantly inhibited H2O2-induced DNA fragmentation and activation of caspases 3 and 9, demonstrating its antiapoptotic action. In addition, only γ-mangostin was found to effectively inhibit lipid peroxidation and DPPH radical formation, while both mangostins inhibited β-secretase activity. Furthermore, we observed that the oral administration of γ-mangostin at dosages of 10 and 30 mg/kg markedly improved scopolamine-induced memory impairment in mice. Collectively, these results provide both in vitro and in vivo evidences for the neuroprotective and memory enhancing effects of γ-mangostin. Multiple mechanisms underlying this neuroprotective action were suggested in this study. Based on our findings, γ-mangostin could serve as a potentially preferable candidate over α-mangostin in combatting oxidative stress-associated neurodegenerative diseases including Alzheimer’s disease.

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