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Khoshkroodian B, Javid H, Pourbadie HG, Sayyah M. Toll-Like Receptor 1/2 Postconditioning by the Ligand Pam3cys Tempers Posttraumatic Hyperexcitability, Neuroinflammation, and Microglial Response: A Potential Candidate for Posttraumatic Epilepsy. Inflammation 2024:10.1007/s10753-024-02109-z. [PMID: 39044002 DOI: 10.1007/s10753-024-02109-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2024] [Revised: 07/16/2024] [Accepted: 07/16/2024] [Indexed: 07/25/2024]
Abstract
Toll-like receptors (TLRs) are activated by endogenous molecules released from damaged cells and contribute to neuroinflammation following traumatic brain injury (TBI) and epilepsy. TLR1/2 agonist tri-palmitoyl-S-glyceryl-cysteine (Pam3cys) is a vaccine adjuvant with confirmed safety in humans. We assessed impact of TLR1/2 postconditioning by Pam3cys on epileptogenesis and neuroinflammation in male rats, 6, 24, and 48 h after mild-to-moderate TBI. Pam3cys was injected into cerebral ventricles 30 min after controlled cortical impact (CCI) injury. After 24 h, rats underwent chemical kindling by once every other day injections of pentylenetetrazole (PTZ) 35 mg/kg until development of generalized seizures. Number of intact neurons, brain expression of proinflammatory cytokine TNF-α, anti-inflammatory cytokine IL-10, and marker of anti-inflammatory microglia arginase1 (Arg1) were determined by immunoblotting. Astrocytes and macrophage/microglia activation/polarization at the contused area was assessed by double immunostaining with Iba1/Arg1, Iba1/iNOS and GFAP/iNOS, specific antibodies. The CCI-injured rats became kindled by less number of PTZ injections than sham-operated rats (9 versus 14 injections, p < 0.0001). Pam3cys treatment returned the accelerated rate of epileptogenesis in TBI state to the sham level. Pam3cys decreased neural death 48 h after TBI. It decreased TNF-α (6 h post-TBI, p < 0.01), and up-regulated IL-10 (p < 0.01) and Arg1 (p < 0.05) 48 h after TBI. The iNOS-positive cells decreased (p < 0.001) whereas Iba1/Arg1-positive cells enhanced (p < 0.01) after Pam3cys treatment. Pam3cys inhibits TBI-accelerated acquisition of seizures. Pam3cys reprograms microglia and up-regulates anti-inflammatory cytokines during the first few days after TBI. This capacity along with the clinical safety, makes Pam3cys a potential candidate for development of effective medications against posttraumatic epilepsy.
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Affiliation(s)
- Bahar Khoshkroodian
- Department of Physiology and Pharmacology, Pasteur Institute of Iran, Pasteur Street, Tehran, 13169455, Iran
| | - Hanieh Javid
- Department of Physiology and Pharmacology, Pasteur Institute of Iran, Pasteur Street, Tehran, 13169455, Iran
- Department of Neuroscience and Addition, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Hamid Gholami Pourbadie
- Department of Physiology and Pharmacology, Pasteur Institute of Iran, Pasteur Street, Tehran, 13169455, Iran
| | - Mohammad Sayyah
- Department of Physiology and Pharmacology, Pasteur Institute of Iran, Pasteur Street, Tehran, 13169455, Iran.
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Yu C, Deng XJ, Xu D. Microglia in epilepsy. Neurobiol Dis 2023; 185:106249. [PMID: 37536386 DOI: 10.1016/j.nbd.2023.106249] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 07/07/2023] [Accepted: 07/31/2023] [Indexed: 08/05/2023] Open
Abstract
Epilepsy is one of most common chronic neurological disorders, and the antiseizure medications developed by targeting neurocentric mechanisms have not effectively reduced the proportion of patients with drug-resistant epilepsy. Further exploration of the cellular or molecular mechanism of epilepsy is expected to provide new options for treatment. Recently, more and more researches focus on brain network components other than neurons, among which microglia have attracted much attention for their diverse biological functions. As the resident immune cells of the central nervous system, microglia have highly plastic transcription, morphology and functional characteristics, which can change dynamically in a context-dependent manner during the progression of epilepsy. In the pathogenesis of epilepsy, highly reactive microglia interact with other components in the epileptogenic network by performing crucial functions such as secretion of soluble factors and phagocytosis, thus continuously reshaping the landscape of the epileptic brain microenvironment. Indeed, microglia appear to be both pro-epileptic and anti-epileptic under the different spatiotemporal contexts of disease, rendering interventions targeting microglia biologically complex and challenging. This comprehensive review critically summarizes the pathophysiological role of microglia in epileptic brain homeostasis alterations and explores potential therapeutic or modulatory targets for epilepsy targeting microglia.
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Affiliation(s)
- Cheng Yu
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan, Hubei Province 430022, China
| | - Xue-Jun Deng
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan, Hubei Province 430022, China
| | - Da Xu
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan, Hubei Province 430022, China.
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CSF1R inhibitors induce a sex-specific resilient microglial phenotype and functional rescue in a tauopathy mouse model. Nat Commun 2023; 14:118. [PMID: 36624100 PMCID: PMC9829908 DOI: 10.1038/s41467-022-35753-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Accepted: 12/23/2022] [Indexed: 01/10/2023] Open
Abstract
Microglia are central to pathogenesis in many neurological conditions. Drugs targeting colony-stimulating factor-1 receptor (CSF1R) to block microglial proliferation in preclinical disease models have shown mixed outcomes, thus the therapeutic potential of this approach remains unclear. Here, we show that CSF1R inhibitors given by multiple dosing paradigms in the Tg2541 tauopathy mouse model cause a sex-independent reduction in pathogenic tau and reversion of non-microglial gene expression patterns toward a normal wild type signature. Despite greater drug exposure in male mice, only female mice have functional rescue and extended survival. A dose-dependent upregulation of immediate early genes and neurotransmitter dysregulation are observed in the brains of male mice only, indicating that excitotoxicity may preclude functional benefits. Drug-resilient microglia in male mice exhibit morphological and gene expression patterns consistent with increased neuroinflammatory signaling, suggesting a mechanistic basis for sex-specific excitotoxicity. Complete microglial ablation is neither required nor desirable for neuroprotection and therapeutics targeting microglia must consider sex-dependent effects.
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Choi JH, Kwon TW, Jo HS, Ha Y, Cho IH. Gintonin, a Panax ginseng-derived LPA receptor ligand, attenuates kainic acid-induced seizures and neuronal cell death in the hippocampus via anti-inflammatory and anti-oxidant activities. J Ginseng Res 2022; 47:390-399. [DOI: 10.1016/j.jgr.2022.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 10/11/2022] [Accepted: 11/03/2022] [Indexed: 11/15/2022] Open
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Lu CW, Huang YC, Chiu KM, Lee MY, Lin TY, Wang SJ. Enmein Decreases Synaptic Glutamate Release and Protects against Kainic Acid-Induced Brain Injury in Rats. Int J Mol Sci 2021; 22:ijms222312966. [PMID: 34884781 PMCID: PMC8657722 DOI: 10.3390/ijms222312966] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 11/29/2021] [Accepted: 11/29/2021] [Indexed: 12/15/2022] Open
Abstract
This study investigated the effects of enmein, an active constituent of Isodon japonicus Hara, on glutamate release in rat cerebrocortical nerve terminals (synaptosomes) and evaluated its neuroprotective potential in a rat model of kainic acid (KA)-induced glutamate excitotoxicity. Enmein inhibited depolarization-induced glutamate release, FM1-43 release, and Ca2+ elevation in cortical nerve terminals but had no effect on the membrane potential. Removing extracellular Ca2+ and blocking vesicular glutamate transporters, N- and P/Q-type Ca2+ channels, or protein kinase C (PKC) prevented the inhibition of glutamate release by enmein. Enmein also decreased the phosphorylation of PKC, PKC-α, and myristoylated alanine-rich C kinase substrates in synaptosomes. In the KA rat model, intraperitoneal administration of enmein 30 min before intraperitoneal injection of KA reduced neuronal cell death, glial cell activation, and glutamate elevation in the hippocampus. Furthermore, in the hippocampi of KA rats, enmein increased the expression of synaptic markers (synaptophysin and postsynaptic density protein 95) and excitatory amino acid transporters 2 and 3, which are responsible for glutamate clearance, whereas enmein decreased the expression of glial fibrillary acidic protein (GFAP) and CD11b. These results indicate that enmein not only inhibited glutamate release from cortical synaptosomes by suppressing Ca2+ influx and PKC but also increased KA-induced hippocampal neuronal death by suppressing gliosis and decreasing glutamate levels by increasing glutamate uptake.
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Affiliation(s)
- Cheng-Wei Lu
- Department of Anesthesiology, Far-Eastern Memorial Hospital, New Taipei City 22060, Taiwan; (C.-W.L.); (Y.-C.H.)
- Department of Mechanical Engineering, Yuan Ze University, Taoyuan 32003, Taiwan
| | - Yu-Chen Huang
- Department of Anesthesiology, Far-Eastern Memorial Hospital, New Taipei City 22060, Taiwan; (C.-W.L.); (Y.-C.H.)
| | - Kuan-Ming Chiu
- Division of Cardiovascular Surgery, Cardiovascular Center, Far-Eastern Memorial Hospital, New Taipei 22060, Taiwan; (K.-M.C.); (M.-Y.L.)
- Department of Nursing, Asia Eastern University of Science and Technology, New Taipei City 22060, Taiwan
- Department of Photonics Engineering, Yuan Ze University, Taoyuan 32003, Taiwan
| | - Ming-Yi Lee
- Division of Cardiovascular Surgery, Cardiovascular Center, Far-Eastern Memorial Hospital, New Taipei 22060, Taiwan; (K.-M.C.); (M.-Y.L.)
| | - Tzu-Yu Lin
- Department of Anesthesiology, Far-Eastern Memorial Hospital, New Taipei City 22060, Taiwan; (C.-W.L.); (Y.-C.H.)
- Department of Mechanical Engineering, Yuan Ze University, Taoyuan 32003, Taiwan
- Correspondence: (T.-Y.L.); (S.-J.W.)
| | - Su-Jane Wang
- Research Center for Chinese Herbal Medicine, College of Human Ecology, Chang Gung University of Science and Technology, Taoyuan 33303, Taiwan
- School of Medicine, Fu Jen Catholic University, New Taipei City 24205, Taiwan
- Correspondence: (T.-Y.L.); (S.-J.W.)
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Welcome MO, Mastorakis NE. The taste of neuroinflammation: Molecular mechanisms linking taste sensing to neuroinflammatory responses. Pharmacol Res 2021; 167:105557. [PMID: 33737243 DOI: 10.1016/j.phrs.2021.105557] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 03/10/2021] [Accepted: 03/10/2021] [Indexed: 02/07/2023]
Abstract
Evidence indicates a critical role of neuroinflammatory response as an underlying pathophysiological process in several central nervous system disorders, including neurodegenerative diseases. However, the molecular mechanisms that trigger neuroinflammatory processes are not fully known. The discovery of bitter taste receptors in regions other than the oral cavity substantially increased research interests on their functional roles in extra-oral tissues. It is now widely accepted that bitter taste receptors, for instance, in the respiratory, intestinal, reproductive and urinary tracts, are crucial not only for sensing poisonous substances, but also, act as immune sentinels, mobilizing defense mechanisms against pathogenic aggression. The relatively recent discovery of bitter taste receptors in the brain has intensified research investigation on the functional implication of cerebral bitter taste receptor expression. Very recent data suggest that responses of bitter taste receptors to neurotoxins and microbial molecules, under normal condition, are necessary to prevent neuroinflammatory reactions. Furthermore, emerging data have revealed that downregulation of key components of the taste receptor signaling cascade leads to increased oxidative stress and inflammasome signaling in neurons that ultimately culminate in neuroinflammation. Nevertheless, the mechanisms that link taste receptor mediated surveillance of the extracellular milieu to neuroinflammatory responses are not completely understood. This review integrates new data on the molecular mechanisms that link bitter taste receptor sensing to neuroinflammatory responses. The role of bitter taste receptor-mediated sensing of toxigenic substances in brain disorders is also discussed. The therapeutic significance of targeting these receptors for potential treatment of neurodegenerative diseases is also highlighted.
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Affiliation(s)
- Menizibeya O Welcome
- Department of Physiology, Faculty of Basic Medical Sciences, College of Health Sciences, Nile University of Nigeria, Abuja, Nigeria.
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Willner MJ, Xiao Y, Kim HS, Chen X, Xu B, Leong KW. Modeling SARS-CoV-2 infection in individuals with opioid use disorder with brain organoids. J Tissue Eng 2021; 12:2041731420985299. [PMID: 33738089 PMCID: PMC7934045 DOI: 10.1177/2041731420985299] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 12/13/2020] [Indexed: 01/10/2023] Open
Abstract
The COVID-19 pandemic has aggravated a preexisting epidemic: the opioid crisis. Much literature has shown that the circumstances imposed by COVID-19, such as social distancing regulations, medical and financial instability, and increased mental health issues, have been detrimental to those with opioid use disorder (OUD). In addition, unexpected neurological sequelae in COVID-19 patients suggest that COVID-19 compromises neuroimmunity, induces hypoxia, and causes respiratory depression, provoking similar effects as those caused by opioid exposure. Combined conditions of COVID-19 and OUD could lead to exacerbated complications. With limited human in vivo options to study these complications, we suggest that iPSC-derived brain organoid models may serve as a useful platform to investigate the physiological connection between COVID-19 and OUD. This mini-review highlights the advances of brain organoids in other neuropsychiatric and infectious diseases and suggests their potential utility for investigating OUD and COVID-19, respectively.
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Affiliation(s)
- Moshe J Willner
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
| | - Yang Xiao
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
| | - Hye Sung Kim
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
- Institute of Tissue Regeneration Engineering, Dankook University, Cheonan, Republic of Korea
- Department of Regenerative Dental Medicine, College of Dentistry, Dankook University, Cheonan, Republic of Korea
- Cell & Matter Institute, Dankook University, Cheonan, Republic of Korea
| | - Xuejing Chen
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
- Department of Physics, Tsinghua University, Beijing, China
| | - Bin Xu
- Department of Psychiatry, Columbia University Medical Center, New York, NY, USA
| | - Kam W Leong
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
- Department of Systems Biology, Columbia University Irving Medical Center, New York, NY, USA
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8
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Reyes-Mendoza J, Morales T. Prolactin treatment reduces kainic acid-induced gliosis in the hippocampus of ovariectomized female rats. Brain Res 2020; 1746:147014. [DOI: 10.1016/j.brainres.2020.147014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 06/27/2020] [Accepted: 07/06/2020] [Indexed: 12/20/2022]
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9
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Negr1 controls adult hippocampal neurogenesis and affective behaviors. Mol Psychiatry 2019; 24:1189-1205. [PMID: 30651602 DOI: 10.1038/s41380-018-0347-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 12/03/2018] [Accepted: 12/10/2018] [Indexed: 01/08/2023]
Abstract
Recent genome-wide association studies on major depressive disorder have implicated neuronal growth regulator 1 (Negr1), a GPI-anchored cell adhesion molecule in the immunoglobulin LON family. Although Negr1 has been shown to regulate neurite outgrowth and synapse formation, the mechanism through which this protein affects mood disorders is still largely unknown. In this research, we characterized Negr1-deficient (negr1-/-) mice to elucidate the function of Negr1 in anxiety and depression. We found that anxiety- and depression-like behaviors increased in negr1-/- mice compared with wild-type mice. In addition, negr1-/- mice had decreased adult hippocampal neurogenesis compared to wild-type mice. Concurrently, both LTP and mEPSC in the dentate gyrus (DG) region were severely compromised in negr1-/- mice. In our effort to elucidate the underlying molecular mechanisms, we found that lipocalin-2 (Lcn2) expression was decreased in the hippocampus of negr1-/- mice compared to wild-type mice. Heterologous Lcn2 expression in the hippocampal DG of negr1-/- mice rescued anxiety- and depression-like behaviors and restored neurogenesis and mEPSC frequency to their normal levels in these mice. Furthermore, we discovered that Negr1 interacts with leukemia inhibitory factor receptor (LIFR) and modulates LIF-induced Lcn2 expression. Taken together, our data uncovered a novel mechanism of mood regulation by Negr1 involving an interaction between Negr1 and LIFR along with Lcn2 expression.
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10
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Characterization of novel kainic acid analogs as inhibitors of select microglial functions. Eur J Pharmacol 2019; 851:25-35. [DOI: 10.1016/j.ejphar.2019.02.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 02/13/2019] [Accepted: 02/14/2019] [Indexed: 11/21/2022]
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11
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Feng L, Murugan M, Bosco DB, Liu Y, Peng J, Worrell GA, Wang HL, Ta LE, Richardson JR, Shen Y, Wu LJ. Microglial proliferation and monocyte infiltration contribute to microgliosis following status epilepticus. Glia 2019; 67:1434-1448. [PMID: 31179602 DOI: 10.1002/glia.23616] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 03/18/2019] [Accepted: 03/19/2019] [Indexed: 12/15/2022]
Abstract
Microglial activation has been recognized as a major contributor to inflammation of the epileptic brain. Seizures are commonly accompanied by remarkable microgliosis and loss of neurons. In this study, we utilize the CX3CR1GFP/+ CCR2RFP/+ genetic mouse model, in which CX3CR1+ resident microglia and CCR2+ monocytes are labeled with GFP and RFP, respectively. Using a combination of time-lapse two-photon imaging and whole-cell patch clamp recording, we determined the distinct morphological, dynamic, and electrophysiological characteristics of infiltrated monocytes and resident microglia, and the evolution of their behavior at different time points following kainic acid-induced seizures. Seizure activated microglia presented enlarged somas with less ramified processes, whereas, infiltrated monocytes were smaller, highly motile cells that lacked processes. Moreover, resident microglia, but not infiltrated monocytes, proliferate locally in the hippocampus after seizure. Microglial proliferation was dependent on the colony-stimulating factor 1 receptor (CSF-1R) pathway. Pharmacological inhibition of CSF-1R reduced seizure-induced microglial proliferation, which correlated with attenuation of neuronal death without altering acute seizure behaviors. Taken together, we demonstrated that proliferation of activated resident microglia contributes to neuronal death in the hippocampus via CSF-1R after status epilepticus, providing potential therapeutic targets for neuroprotection in epilepsy.
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Affiliation(s)
- Lijie Feng
- School of Basic Medical Sciences, Anhui Medical University, Hefei, Anhui, China.,Department of Cell Biology and Neuroscience, School of Arts and Sciences, Rutgers University, Piscataway, New Jersey
| | - Madhuvika Murugan
- Department of Cell Biology and Neuroscience, School of Arts and Sciences, Rutgers University, Piscataway, New Jersey.,Department of Neurology, Mayo Clinic, Rochester, Minnesota
| | - Dale B Bosco
- Department of Neurology, Mayo Clinic, Rochester, Minnesota
| | - Yong Liu
- Department of Neurology, Mayo Clinic, Rochester, Minnesota
| | - Jiyun Peng
- Department of Cell Biology and Neuroscience, School of Arts and Sciences, Rutgers University, Piscataway, New Jersey.,Department of Neurology, Mayo Clinic, Rochester, Minnesota
| | | | - Hai-Long Wang
- Department of Neurology, Mayo Clinic, Rochester, Minnesota
| | - Lauren E Ta
- Department of Neurology, Mayo Clinic, Rochester, Minnesota
| | - Jason R Richardson
- Department of Environmental Health Sciences, Robert Stempel School of Public Health and Social Work, Florida International University, Miami, Florida
| | - Yuxian Shen
- School of Basic Medical Sciences, Anhui Medical University, Hefei, Anhui, China
| | - Long-Jun Wu
- Department of Cell Biology and Neuroscience, School of Arts and Sciences, Rutgers University, Piscataway, New Jersey.,Department of Neurology, Mayo Clinic, Rochester, Minnesota.,Department of Neuroscience, Mayo Clinic, Jacksonville, Florida.,Department of Immunology, Mayo Clinic, Rochester, Minnesota
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12
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Lee EJ, Park JS, Lee YY, Kim DY, Kang JL, Kim HS. Anti-inflammatory and anti-oxidant mechanisms of an MMP-8 inhibitor in lipoteichoic acid-stimulated rat primary astrocytes: involvement of NF-κB, Nrf2, and PPAR-γ signaling pathways. J Neuroinflammation 2018; 15:326. [PMID: 30470240 PMCID: PMC6260848 DOI: 10.1186/s12974-018-1363-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Accepted: 11/07/2018] [Indexed: 01/06/2023] Open
Abstract
Background Recent evidence suggests that reactive astrocytes play an important role in neuroinflammation and neurodegenerative diseases. Thus, controlling astrocyte reactivity has been suggested as a promising strategy for treating neurodegenerative diseases. In the present study, we investigated whether a matrix metalloproteinase (MMP)-8 inhibitor, M8I, could control neuroinflammation in lipoteichoic acid (LTA)-stimulated rat primary astrocytes. Methods The effects of M8I on the expression of inducible nitric oxide synthase, cytokines, and MMPs were examined in LTA-stimulated rat primary astrocytes by ELISA, RT-PCR, and Western blot analysis. The effects of M8I on reactive oxygen species (ROS) generation and phase II antioxidant enzyme expression were examined by the DCF-DA assay, RT-PCR, and Western blot analysis. The detailed molecular mechanisms underlying the anti-inflammatory and antioxidant effects of M8I were analyzed by the electrophoretic mobility shift assay, the reporter gene assay, Western blot, and RT-PCR analysis. Results Treatment with LTA, a major cell wall component of Gram-positive bacteria, led to astrocyte activation and induced the expression of inflammatory molecules such as iNOS, COX-2, and pro-inflammatory cytokines. In addition, LTA induced the expression of MMPs such as MMP-1, MMP-3, MMP-8, MMP-9, and MMP-13 in rat primary astrocytes. Based on previous reports showing that MMP-8 plays a role as a proinflammatory mediator in microglia, we investigated whether MMP-8 is also involved in inflammatory reactions of reactive astrocytes. We found that treatment of astrocytes with M8I significantly inhibited LTA-induced expression of iNOS, TNF-α, IL-1β, IL-6, and TLR-2. In addition, M8I inhibited LTA-induced NF-κB, MAP kinase, and Akt activities, while it increased the anti-inflammatory PPAR-γ activities. Moreover, M8I showed antioxidant effects by suppressing ROS production in LTA- or H2O2-stimulated astrocytes. Interestingly, M8I increased the expression of phase II antioxidant enzymes such as hemeoxygenase-1, NQO1, catalase, and MnSOD by modulating the Nrf2/ARE signaling pathway. Conclusions The data collectively suggest the therapeutic potential of an MMP-8 inhibitor in neuroinflammatory disorders that are associated with astrocyte reactivity. Electronic supplementary material The online version of this article (10.1186/s12974-018-1363-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Eun-Jung Lee
- Department of Molecular Medicine, Tissue Injury Defense Research Center, School of Medicine, Ewha Womans University, Mok-6-dong 911-1, Yangchun-Ku, Seoul, 158-710, South Korea
| | - Jin-Sun Park
- Department of Molecular Medicine, Tissue Injury Defense Research Center, School of Medicine, Ewha Womans University, Mok-6-dong 911-1, Yangchun-Ku, Seoul, 158-710, South Korea
| | - Yu-Young Lee
- Department of Molecular Medicine, Tissue Injury Defense Research Center, School of Medicine, Ewha Womans University, Mok-6-dong 911-1, Yangchun-Ku, Seoul, 158-710, South Korea
| | - Do-Yeon Kim
- Department of Molecular Medicine, Tissue Injury Defense Research Center, School of Medicine, Ewha Womans University, Mok-6-dong 911-1, Yangchun-Ku, Seoul, 158-710, South Korea
| | - Jihee Lee Kang
- Department of Physiology, Tissue Injury Defense Research Center, School of Medicine, Ewha Womans University, Seoul, South Korea
| | - Hee-Sun Kim
- Department of Molecular Medicine, Tissue Injury Defense Research Center, School of Medicine, Ewha Womans University, Mok-6-dong 911-1, Yangchun-Ku, Seoul, 158-710, South Korea.
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13
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Wu X, Xie S, Wang L, Fan P, Ge S, Xie XQ, Wu W. A computational strategy for finding novel targets and therapeutic compounds for opioid dependence. PLoS One 2018; 13:e0207027. [PMID: 30403753 PMCID: PMC6221321 DOI: 10.1371/journal.pone.0207027] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 10/22/2018] [Indexed: 12/13/2022] Open
Abstract
Opioids are widely used for treating different types of pains, but overuse and abuse of prescription opioids have led to opioid epidemic in the United States. Besides analgesic effects, chronic use of opioid can also cause tolerance, dependence, and even addiction. Effective treatment of opioid addiction remains a big challenge today. Studies on addictive effects of opioids focus on striatum, a main component in the brain responsible for drug dependence and addiction. Some transcription regulators have been associated with opioid addiction, but relationship between analgesic effects of opioids and dependence behaviors mediated by them at the molecular level has not been thoroughly investigated. In this paper, we developed a new computational strategy that identifies novel targets and potential therapeutic molecular compounds for opioid dependence and addiction. We employed several statistical and machine learning techniques and identified differentially expressed genes over time which were associated with dependence-related behaviors after exposure to either morphine or heroin, as well as potential transcription regulators that regulate these genes, using time course gene expression data from mouse striatum. Moreover, our findings revealed that some of these dependence-associated genes and transcription regulators are known to play key roles in opioid-mediated analgesia and tolerance, suggesting that an intricate relationship between opioid-induce pain-related pathways and dependence may develop at an early stage during opioid exposure. Finally, we determined small compounds that can potentially target the dependence-associated genes and transcription regulators. These compounds may facilitate development of effective therapy for opioid dependence and addiction. We also built a database (http://daportals.org) for all opioid-induced dependence-associated genes and transcription regulators that we discovered, as well as the small compounds that target those genes and transcription regulators.
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Affiliation(s)
- Xiaojun Wu
- Computational Biology Department, School of Computer Science, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Siwei Xie
- Computational Biology Department, School of Computer Science, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Lirong Wang
- Department of Pharmaceutical Sciences and Computational Chemical Genomics Screening Center, School of Pharmacy, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Drug Discovery Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Peihao Fan
- Department of Pharmaceutical Sciences and Computational Chemical Genomics Screening Center, School of Pharmacy, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Songwei Ge
- School of Information, Renmin University of China, Beijing, China
| | - Xiang-Qun Xie
- Department of Pharmaceutical Sciences and Computational Chemical Genomics Screening Center, School of Pharmacy, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Drug Discovery Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Computational and Systems Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Structural Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Wei Wu
- Computational Biology Department, School of Computer Science, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
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14
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Semlali A, Almutairi M, Rouabhia M, Reddy Parine N, Al Amri A, S. Al-Numair N, M. Hawsawi Y, Saud Alanazi M. Novel sequence variants in the TLR6 gene associated with advanced breast cancer risk in the Saudi Arabian population. PLoS One 2018; 13:e0203376. [PMID: 30388713 PMCID: PMC6214682 DOI: 10.1371/journal.pone.0203376] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 08/21/2018] [Indexed: 02/07/2023] Open
Abstract
Herein, we evaluated the association of the Toll-like receptor 6 (TLR6) single nucleotide polymorphisms (SNPs) rs3796508 (Val327Met) and rs5743810 (Ser249Pro) with breast cancer (BC) susceptibility in Saudi Arabian women, using in silico analysis. We found no significant differences in genotypic and allelic frequencies for rs3796508 between the BC patients (n = 127) and healthy individuals (n = 116). However, 86% of the BC patients, versus 98% of the healthy controls, carried the rs5743810 Pro allele (OR = 0.103, CI = 0.036–0.293, P = 0.00001). Advanced analysis based on the comparison of the estrogen receptor (ER)-positive and -negative patients with the healthy controls indicated a significant association between rs5743810 allelic frequency and BC risk protection (OR = 0.100, CI = 0.034–0.297, P = 0.00001 for ER+ BC cases; OR = 0.102, CI = 0.033–0.318, P = 0.00001 for ER−BC cases). Furthermore, rs5743810 was associated with BC risk protection at either above or below 48 years of age at diagnosis (OR = 0.101, CI = 0.022–0.455, P = 0.00037 for age ≤48 years; OR = 0.120, CI = 0.028–0.519, P = 0.00087 for age >48 years). Such associations were not found for rs3796508. In silico analysis indicated that these SNPs had neutral effects within the TLR6 structure, confirming the protective role of rs5743810. Our findings therefore suggest a strong association between rs5743810 and protection against BC risk in Saudi Arabian women. Importantly, the rs5743810 Pro allele could be a potential BC diagnostic biomarker in this ethnic population.
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Affiliation(s)
- Abdelhabib Semlali
- Groupe de Recherche en Écologie Buccale, Département de stomatologie, Faculté de Médecine Dentaire, Université Laval, Québec, Qc, Canada
- Genome Research Chair, Department of Biochemistry, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia
- * E-mail: ,
| | - Mikhlid Almutairi
- Zoology Department, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Mahmoud Rouabhia
- Groupe de Recherche en Écologie Buccale, Département de stomatologie, Faculté de Médecine Dentaire, Université Laval, Québec, Qc, Canada
| | - Narasimha Reddy Parine
- Genome Research Chair, Department of Biochemistry, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Abdullah Al Amri
- Groupe de Recherche en Écologie Buccale, Département de stomatologie, Faculté de Médecine Dentaire, Université Laval, Québec, Qc, Canada
| | - Nouf S. Al-Numair
- Department of Genetics, Research Center, King Faisal Specialist Hospital and Research Center, Riyadh, Kingdom of Saudi Arabia
- College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Yousef M. Hawsawi
- Department of Genetics, Research Center, King Faisal Specialist Hospital and Research Center, Riyadh, Kingdom of Saudi Arabia
| | - Mohammad Saud Alanazi
- Genome Research Chair, Department of Biochemistry, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia
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15
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Gangoso E, Talaverón R, Jaraíz-Rodríguez M, Domínguez-Prieto M, Ezan P, Koulakoff A, Medina JM, Giaume C, Tabernero A. A c-Src Inhibitor Peptide Based on Connexin43 Exerts Neuroprotective Effects through the Inhibition of Glial Hemichannel Activity. Front Mol Neurosci 2017; 10:418. [PMID: 29326548 PMCID: PMC5737028 DOI: 10.3389/fnmol.2017.00418] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Accepted: 12/01/2017] [Indexed: 12/29/2022] Open
Abstract
The non-receptor tyrosine kinase c-Src is an important mediator in several signaling pathways related to neuroinflammation. Our previous study showed that cortical injection of kainic acid (KA) promoted a transient increase in c-Src activity in reactive astrocytes surrounding the neuronal lesion. As a cell-penetrating peptide based on connexin43 (Cx43), specifically TAT-Cx43266–283, inhibits Src activity, we investigated the effect of TAT-Cx43266–283 on neuronal death promoted by cortical KA injections in adult mice. As expected, KA promoted neuronal death, estimated by the reduction in NeuN-positive cells and reactive gliosis, characterized by the increase in glial fibrillary acidic protein (GFAP) expression. Interestingly, TAT-Cx43266–283 injected with KA diminished neuronal death and reactive gliosis compared to KA or KA+TAT injections. In order to gain insight into the neuroprotective mechanism, we used in vitro models. In primary cultured neurons, TAT-Cx43266–283 did not prevent neuronal death promoted by KA, but when neurons were grown on top of astrocytes, TAT-Cx43266–283 prevented neuronal death promoted by KA. These observations demonstrate the participation of astrocytes in the neuroprotective effect of TAT-Cx43266–283. Furthermore, the neuroprotective effect was also present in non-contact co-cultures, suggesting the contribution of soluble factors released by astrocytes. As glial hemichannel activity is associated with the release of several factors, such as ATP and glutamate, that cause neuronal death, we explored the participation of these channels on the neuroprotective effect of TAT-Cx43266–283. Our results confirmed that inhibitors of ATP and NMDA receptors prevented neuronal death in co-cultures treated with KA, suggesting the participation of astrocyte hemichannels in neurotoxicity. Furthermore, TAT-Cx43266–283 reduced hemichannel activity promoted by KA in neuron-astrocyte co-cultures as assessed by ethidium bromide (EtBr) uptake assay. In fact, TAT-Cx43266–283 and dasatinib, a potent c-Src inhibitor, strongly reduced the activation of astrocyte hemichannels. In conclusion, our results suggest that TAT-Cx43266–283 exerts a neuroprotective effect through the reduction of hemichannel activity likely mediated by c-Src in astrocytes. These data unveil a new role of c-Src in the regulation of Cx43-hemichannel activity that could be part of the mechanism by which astroglial c-Src participates in neuroinflammation.
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Affiliation(s)
- Ester Gangoso
- MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Collège de France, Université Pierre et Marie Curie, Paris, France
| | - Rocío Talaverón
- Departamento de Bioquímica y Biología Molecular, Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Salamanca, Spain
| | - Myriam Jaraíz-Rodríguez
- Departamento de Bioquímica y Biología Molecular, Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Salamanca, Spain
| | - Marta Domínguez-Prieto
- Departamento de Bioquímica y Biología Molecular, Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Salamanca, Spain
| | - Pascal Ezan
- MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Collège de France, Université Pierre et Marie Curie, Paris, France
| | - Annette Koulakoff
- MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Collège de France, Université Pierre et Marie Curie, Paris, France
| | - José M Medina
- Departamento de Bioquímica y Biología Molecular, Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Salamanca, Spain
| | - Christian Giaume
- MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Collège de France, Université Pierre et Marie Curie, Paris, France
| | - Arantxa Tabernero
- Departamento de Bioquímica y Biología Molecular, Instituto de Neurociencias de Castilla y León (INCYL), Universidad de Salamanca, Salamanca, Spain
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16
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Medel-Matus JS, Reynolds A, Shin D, Sankar R, Mazarati A. Regulation of kindling epileptogenesis by hippocampal Toll-like receptors 2. Epilepsia 2017; 58:e122-e126. [PMID: 28632301 PMCID: PMC5554076 DOI: 10.1111/epi.13826] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/24/2017] [Indexed: 11/29/2022]
Abstract
This study examined whether Toll-like receptors 2 (TLR2) contribute to rapid kindling epileptogenesis. A TLR2 agonist, lipoteichoic acid (LTA), LTA antibody (LTA-A), or normal saline (control) was administered daily over 3 consecutive days, unilaterally into ventral hippocampus of adult male Wistar rats. Thirty minutes after the last injection, the animals were subjected to a rapid kindling procedure. The ictogenesis was gauged by comparing afterdischarge threshold (ADT) and afterdischarge duration (ADD) before the treatments, after the treatments prior to kindling, and 24 h after kindling. Kindling progression and retention were analyzed using video recording. The results showed that before kindling, LTA produced an ADT reduction. Neither LTA nor LTA-A affected baseline ADD. On kindling progression, LTA accelerated occurrence of generalized seizures, whereas LTA-A delayed this effect. Treatment with LTA-A reduced the number of secondary generalized complex partial seizures. Twenty-four hours after kindling, the rats of both the saline and LTA groups showed increased hippocampal excitability as compared with prekindling parameters. Administration of LTA-A prevented kindling-induced increase of hippocampal excitability. Immunostaining revealed that LTA-A attenuated the inflammatory response produced by seizures. These findings suggest that the activation of TLR2 in the hippocampus may facilitate limbic epileptogenesis.
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Affiliation(s)
| | - Ashley Reynolds
- Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, California, U.S.A
| | - Don Shin
- Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, California, U.S.A
| | - Raman Sankar
- Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, California, U.S.A
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, California, U.S.A
- UCLA Children’s Discovery and Innovation Institute, Los Angeles, California, U.S.A
| | - Andrey Mazarati
- Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, California, U.S.A
- UCLA Children’s Discovery and Innovation Institute, Los Angeles, California, U.S.A
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17
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Wang FX, Xiong XY, Zhong Q, Meng ZY, Yang H, Yang QW. Foxp3 exhibits antiepileptic effects in ictogenesis involved in TLR4 signaling. FASEB J 2017; 31:2948-2962. [PMID: 28386044 DOI: 10.1096/fj.201600989r] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 03/13/2017] [Indexed: 11/11/2022]
Abstract
Inflammatory processes play critical roles in epileptogenesis, but the exact mechanisms that underlie these processes are still not completely understood. In this study, we investigated the role of forkhead transcription factor 3 (Foxp3), a transcription factor that is involved in T-cell differentiation, in epileptogenesis. In both human epileptic tissues and experimental seizure models, we found significant up-regulation of Foxp3 in neurons and glial cells. Of importance, Foxp3-/- mice were susceptible to kainic acid-induced seizures, whereas overexpression of Foxp3 reduced acute seizure occurrence and decreased chronic seizure recurrence. In addition, in vitro experiments revealed that Foxp3 inhibited neuronal excitability via glial cells and not neurons. The protective effects of Foxp3 were manifested as a reduction in glial cell activation and proinflammatory cytokine production and increased neuronal survival. Moreover, we showed that beneficial effects of Foxp3 involved the attenuation of TLR4 signaling and inflammation, which led to the inactivation of NR2B-containing NMDA receptors. These results suggest that Foxp3 in glial cells may play an antiepileptic role in epileptogenesis and may act as a modulator of TLR4. Taken together, our results indicate that Foxp3 may represent a novel therapeutic target for achieving anticonvulsant effects in patients with epilepsy that is currently resistant to drugs.-Wang, F.-X., Xiong, X.-Y., Zhong, Q., Meng, Z.-Y., Yang, H., Yang, Q.-W. Foxp3 exhibits antiepileptic effects in ictogenesis involved in TLR4 signaling.
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Affiliation(s)
- Fa-Xiang Wang
- Department of Neurology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Xiao-Yi Xiong
- Department of Neurology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Qi Zhong
- Department of Neurology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Zhao-You Meng
- Department of Neurology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Hui Yang
- Department of Neurosurgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Qing-Wu Yang
- Department of Neurology, Xinqiao Hospital, Third Military Medical University, Chongqing, China;
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18
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Involvement of Toll Like Receptor 2 Signaling in Secondary Injury during Experimental Diffuse Axonal Injury in Rats. Mediators Inflamm 2017; 2017:1570917. [PMID: 28293064 PMCID: PMC5331293 DOI: 10.1155/2017/1570917] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 12/17/2016] [Accepted: 01/04/2017] [Indexed: 12/16/2022] Open
Abstract
Treatment of diffuse axonal injury (DAI) remains challenging in clinical practice due to the unclear pathophysiological mechanism. Uncontrolled, excessive inflammation is one of the most recognized mechanisms that contribute to the secondary injury after DAI. Toll like receptor 2 (TLR2) is highlighted for the initiation of a vicious self-propagating inflammatory circle. However, the role and detailed mechanism of TLR2 in secondary injury is yet mostly unknown. In this study, we demonstrated the expression of TLR2 levels in cortex, corpus callosum, and internal capsule and the localization of TLR2 in neurons and glial cells in rat DAI models. Intracerebral knockdown of TLR2 significantly downregulated TLR2 expression, attenuated cortical apoptosis, lessened glial response, and reduced the secondary axonal and neuronal injury in the cortex by inhibiting phosphorylation of mitogen-activated protein kinases (MAPK) including Erk, JNK, and p38, translocation of NF-κB p65 from the cytoplasm to the nucleus, and decreasing levels of proinflammatory cytokines including interleukin-6, interleukin-1β, and tumor necrosis factor-α. On the contrary, administration of TLR2 agonist to DAI rats achieved an opposite effect. Collectively, we demonstrated that TLR2 was involved in mediating secondary injury after DAI by inducing inflammation via the MAPK and NF-κB pathways.
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19
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Abstract
Lidocaine, the most commonly used local anesthetic, inhibits glutamate release from nerve terminals. Given the involvement of glutamate neurotoxicity in the pathogenesis of various neurological disorders, this study investigated the role of lidocaine in hippocampal neuronal death and inflammatory events induced by an i.p. injection of kainic acid (KA) (15 mg/kg), a glutamate analog. The results showed that KA significantly led to neuronal death in the CA3 pyramidal layers of the hippocampus and this effect was attenuated by the systemic administration of lidocaine (0.8 or 4 mg/kg, i.p.) 30 min before KA injection. Moreover, KA-induced microglia activation and gene expression of proinflammatory cytokines, namely, interleukin-1β, interleukin-6, and tumor necrosis factor-α, in the hippocampus were reduced by the lidocaine pretreatment. Altogether, the results suggest that lidocaine can effectively treat glutamate excitotoxicity-related brain disorders.
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20
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Pérez-Juárez A, Chamorro G, Alva-Sánchez C, Paniagua-Castro N, Pacheco-Rosado J. Neuroprotective effect of Arthrospira (Spirulina) platensis against kainic acid-neuronal death. PHARMACEUTICAL BIOLOGY 2016; 54:1408-1412. [PMID: 26799655 DOI: 10.3109/13880209.2015.1103756] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Context Arthrospira (Spirulina) platensis (SP) is a cyanobacterium which has attracted attention because of its nutritional value and pharmacological properties. It was previously reported that SP reduces oxidative stress in the hippocampus and protects against damaging neurobehavioural effects of systemic kainic acid (KA). It is widely known that the systemic administration of KA induces neuronal damage, specifically in the CA3 hippocampal region. Objective The present study determines if the SP sub-chronic treatment has neuroprotective properties against KA. Materials and methods Male SW mice were treated with SP during 24 d, at doses of 0, 200, and 800 mg/kg, once daily, and with KA (35 mg/kg, ip) as a single dose on day 14. After the treatment, a histological analysis was performed and the number of atrophic neuronal cells in CA3 hippocampal region was quantified. Results Pretreatment with SP does not protect against seizures induced by KA. However, mortality in the SP 200 and the SP 800 groups was of 20%, while for the KA group, it was of 60%. A single KA ip administration produced a considerable neuronal damage, whereas both doses of SP sub-chronic treatment reduced the number of atrophic neurons in CA3 hippocampal region with respect to the KA group. Discussion The SP neurobehaviour improvement after KA systemic administration correlates with the capacity of SP to reduce KA-neuronal death in CA3 hippocampal cells. This neuroprotection may be related to the antioxidant properties of SP. Conclusion SP reduces KA-neuronal death in CA3 hippocampal cells.
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Affiliation(s)
- Angélica Pérez-Juárez
- a Department of Pharmacy
- c Department of Physiology, Escuela Superior De Medicina , Instituto Politécnico Nacional , México , DF , México
| | | | - Claudia Alva-Sánchez
- b Department of Physiology , Escuela Nacional De Ciencias Biológicas, Instituto Politécnico Nacional, Unidad Profesional Adolfo López Mateos , México , DF , México
| | - Norma Paniagua-Castro
- b Department of Physiology , Escuela Nacional De Ciencias Biológicas, Instituto Politécnico Nacional, Unidad Profesional Adolfo López Mateos , México , DF , México
| | - Jorge Pacheco-Rosado
- b Department of Physiology , Escuela Nacional De Ciencias Biológicas, Instituto Politécnico Nacional, Unidad Profesional Adolfo López Mateos , México , DF , México
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21
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Lee MJ, Bing SJ, Choi J, Jang M, Lee G, Lee H, Chang BS, Jee Y, Lee SJ, Cho IH. IKKβ-mediated inflammatory myeloid cell activation exacerbates experimental autoimmune encephalomyelitis by potentiating Th1/Th17 cell activation and compromising blood brain barrier. Mol Neurodegener 2016; 11:54. [PMID: 27450563 PMCID: PMC4957872 DOI: 10.1186/s13024-016-0116-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 07/02/2016] [Indexed: 01/31/2023] Open
Abstract
Background The inflammatory myeloid cell activation is one of the hallmarks of experimental autoimmune encephalomyelitis (EAE), yet the in vivo role of the inflammatory myeloid cell activation in EAE has not been clearly resolved. It is well-known that IKK/NF-κB is a key signaling pathway that regulates inflammatory myeloid activation. Methods We investigated the in vivo role of inflammatory myeloid cell activation in myelin oligodendrocyte glycoprotein (MOG) peptides-induced EAE using myeloid cell type-specific ikkβ gene conditional knockout-mice (LysM-Cre/IkkβF/F). Results In our study, LysM-Cre/IkkβF/F mice had alleviated clinical signs of EAE corresponding to the decreased spinal demyelination, microglial activation, and immune cell infiltration in the spinal cord, compared to the wild-type mice (WT, IkkβF/F). Myeloid ikkβ gene deletion significantly reduced the percentage of CD4+/IFN-γ+ (Th1) and CD4+/IL-17+ (Th17) cells but increased the percentages of CD4+/CD25+/Foxp3+ (Treg) cells in the spinal cord and lymph nodes, corresponding to the altered mRNA expression of IFN-γ, IL-17, IL-23, and Foxp3 in the spinal cords of LysM-Cre/IkkβF/F EAE mice. Also, the beneficial effect of myeloid IKKβ deletion in EAE corresponded to the decreased permeability of the blood brain barrier (BBB). Conclusions Our findings strongly suggest that IKK/NF-kB-induced myeloid cell activation exacerbates EAE by activating Th1 and Th17 responses and compromising the BBB. The development of NF-κB inhibitory agents with high efficacy through specific targeting of IKKβ in myeloid cells might be of therapeutic potential in MS and other autoimmune disorders. Electronic supplementary material The online version of this article (doi:10.1186/s13024-016-0116-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Min Jung Lee
- Department of Convergence Medical Science, College of Korean Medicine, Kyung Hee University, Seoul, 02447, Republic of Korea.,Brain Korea 21 Plus Program, College of Korean Medicine, Kyung Hee University, Seoul, 02447, Republic of Korea
| | - So Jin Bing
- Department of Veterinary Medicine, Jeju National University, Jeju, 63243, Republic of Korea
| | - Jonghee Choi
- Department of Convergence Medical Science, College of Korean Medicine, Kyung Hee University, Seoul, 02447, Republic of Korea.,Brain Korea 21 Plus Program, College of Korean Medicine, Kyung Hee University, Seoul, 02447, Republic of Korea
| | - Minhee Jang
- Department of Convergence Medical Science, College of Korean Medicine, Kyung Hee University, Seoul, 02447, Republic of Korea
| | - Gihyun Lee
- Department of Physiology, College of Korean Medicine, Kyung Hee University, Seoul, 02447, Republic of Korea
| | - Hyunkyoung Lee
- Department of Neuroscience and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, 08826, Republic of Korea
| | - Byung Soo Chang
- Department of Cosmetology, Hanseo University, Seosan, 31962, Republic of Korea
| | - Youngheun Jee
- Department of Veterinary Medicine, Jeju National University, Jeju, 63243, Republic of Korea
| | - Sung Joong Lee
- Department of Neuroscience and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, 08826, Republic of Korea.
| | - Ik-Hyun Cho
- Department of Convergence Medical Science, College of Korean Medicine, Kyung Hee University, Seoul, 02447, Republic of Korea. .,Brain Korea 21 Plus Program, College of Korean Medicine, Kyung Hee University, Seoul, 02447, Republic of Korea. .,Institute of Korean Medicine, College of Korean Medicine, Kyung Hee University, Seoul, 02447, Republic of Korea.
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22
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Jin S, Kim JG, Park JW, Koch M, Horvath TL, Lee BJ. Hypothalamic TLR2 triggers sickness behavior via a microglia-neuronal axis. Sci Rep 2016; 6:29424. [PMID: 27405276 PMCID: PMC4942617 DOI: 10.1038/srep29424] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 06/17/2016] [Indexed: 12/16/2022] Open
Abstract
Various pathophysiologic mechanisms leading to sickness behaviors have been proposed. For example, an inflammatory process in the hypothalamus has been implicated, but the signaling modalities that involve inflammatory mechanisms and neuronal circuit functions are ill-defined. Here, we show that toll-like receptor 2 (TLR2) activation by intracerebroventricular injection of its ligand, Pam3CSK4, triggered hypothalamic inflammation and activation of arcuate nucleus microglia, resulting in altered input organization and increased activity of proopiomelanocortin (POMC) neurons. These animals developed sickness behavior symptoms, including anorexia, hypoactivity, and hyperthermia. Antagonists of nuclear factor kappa B (NF-κB), cyclooxygenase pathway and melanocortin receptors 3/4 reversed the anorexia and body weight loss induced by TLR2 activation. These results unmask an important role of TLR2 in the development of sickness behaviors via stimulation of hypothalamic microglia to promote POMC neuronal activation in association with hypothalamic inflammation.
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Affiliation(s)
- Sungho Jin
- Department of Biological Sciences, University of Ulsan, Ulsan, 680-749, Republic of Korea
| | - Jae Geun Kim
- Division of Life Sciences, College of Life Sciences and Bioengineering, Incheon National University, Incheon, 406-772, Republic of Korea.,Program in Integrative Cell Signaling and Neurobiology of Metabolism, Section of Comparative Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Jeong Woo Park
- Department of Biological Sciences, University of Ulsan, Ulsan, 680-749, Republic of Korea
| | - Marco Koch
- Program in Integrative Cell Signaling and Neurobiology of Metabolism, Section of Comparative Medicine, Yale University School of Medicine, New Haven, CT 06520, USA.,Institute of Anatomy, University of Leipzig, 04103 Leipzig, Germany
| | - Tamas L Horvath
- Program in Integrative Cell Signaling and Neurobiology of Metabolism, Section of Comparative Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Byung Ju Lee
- Department of Biological Sciences, University of Ulsan, Ulsan, 680-749, Republic of Korea
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23
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Wieck A, Grassi-Oliveira R, do Prado CH, Viola TW, Petersen LE, Porto B, Teixeira AL, Bauer ME. Toll-like receptor expression and function in type I bipolar disorder. Brain Behav Immun 2016; 54:110-121. [PMID: 26795430 DOI: 10.1016/j.bbi.2016.01.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 01/08/2016] [Accepted: 01/13/2016] [Indexed: 12/12/2022] Open
Abstract
Bipolar disorder (BD) has been associated with immune imbalance and low-grade inflammation. The underlying mechanisms remain largely obscure but may involve changes in cell signaling. Toll-like receptors (TLRs) are widely expressed by immune cells. Specific binding of TLRs to pathogen- or danger-associated signals leads to inflammatory responses. Here, we analyzed the frequencies of TLR-1, TLR-2, TLR-4, TLR-5 and TLR-6 in monocytes, regulatory T cells (Tregs) and activated T cells from type I BD euthymic patients and healthy controls (HCs). Monocytes were stimulated in vitro with specific TLR agonists (flagellin, LPS, LTA, BLP and PGN) and immunophenotyped. Cytokines (IL-8, IL-1beta, IL-6, IL-10, TNF-alpha and IL-12p70) were assessed with cytometric bead arrays. At baseline, increased percentages of TLR-1+ and TLR-2+ monocytes and reduced expression of TLR-5 were observed in BD. Following stimulation, the percentage of TLR-1+, TLR-2+, and TLR-6+ monocytes was higher in BD subjects than in HCs. Increased levels of IL-8, IL-12p70 and TNF were observed following stimulation with TLR-1, TLR-2 and TLR-6 agonists, suggesting increased signaling via these receptors in BD. In contrast to HCs, BD patients exhibited no changes in TLR-5 expression following stimulation. The percentage of TLR-2+ Treg cells as well as activated T cells expressing both TLR-2 and TLR-5 increased in BD patients. Given the importance of TLRs in triggering immune responses, our data indicate a role for these receptors in the low-grade inflammatory profile documented in BD.
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Affiliation(s)
- Andrea Wieck
- Laboratory of Immunosenescence, Institute of Biomedical Research, Pontifical Catholic University of the Rio Grande do Sul (PUCRS), Porto Alegre, Brazil; Postgraduate Program in Biomedical Gerontology, Brazil
| | - Rodrigo Grassi-Oliveira
- Laboratory of Immunosenescence, Institute of Biomedical Research, Pontifical Catholic University of the Rio Grande do Sul (PUCRS), Porto Alegre, Brazil; Cognitive Neuroscience Research Group (GNCD), Centre of Studies and Research in Traumatic Stress (NEPTE), Postgraduate Program in Psychology, PUCRS, Porto Alegre, Brazil
| | - Carine Hartmann do Prado
- Laboratory of Immunosenescence, Institute of Biomedical Research, Pontifical Catholic University of the Rio Grande do Sul (PUCRS), Porto Alegre, Brazil
| | - Thiago Wendt Viola
- Cognitive Neuroscience Research Group (GNCD), Centre of Studies and Research in Traumatic Stress (NEPTE), Postgraduate Program in Psychology, PUCRS, Porto Alegre, Brazil
| | - Laura Esteves Petersen
- Laboratory of Immunosenescence, Institute of Biomedical Research, Pontifical Catholic University of the Rio Grande do Sul (PUCRS), Porto Alegre, Brazil
| | - Bárbara Porto
- Lab. Imunologia Clínica e Experimental, Institute of Biomedical Research, Pontifical Catholic University of the Rio Grande do Sul (PUCRS), Porto Alegre, Brazil
| | - Antônio Lúcio Teixeira
- Translational Psychoneuroimmunology Group, School of Medicine, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - Moisés Evandro Bauer
- Laboratory of Immunosenescence, Institute of Biomedical Research, Pontifical Catholic University of the Rio Grande do Sul (PUCRS), Porto Alegre, Brazil; Postgraduate Program in Biomedical Gerontology, Brazil.
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Choi JH, Jang M, Kim EJ, Kim H, Ye SK, Cho IH. Oriental Medicine Woohwangchungsimwon Attenuates Kainic Acid-Induced Seizures and Neuronal Cell Death in the Hippocampus. Rejuvenation Res 2016; 19:394-405. [PMID: 26981959 DOI: 10.1089/rej.2015.1779] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Woohwangchungsimwon (WCW) is an oriental medicine that has been extensively prescribed in Asia to patients with apoplexy, high blood pressure, acute/chronic convulsion, and so on. However, the potential therapeutic value of WCW in treating the pathologic brain has not yet been fully investigated. In the present study, we evaluated whether WCW has beneficial effects on kainic acid (KA)-induced excitotoxicity. An intraperitoneal injection of KA (40 mg/kg) and an intracerebroventricular injection of KA (0.2 μg) produced typical seizure behavior and neuronal cell death in the CA1 and CA3 pyramidal layers of the hippocampus, respectively. However, the systemic administration of WCW significantly attenuated the seizure behavior and neuronal cell death. WCW was found to exert the best protective effect when it was administrated 2 hours before a KA injection. Moreover, this WCW-induced neuroprotection was accompanied by a reduction in microglia activation and tumor necrosis factor-alpha, interleukin (IL)-1β, IL-6, inducible nitric oxide synthase, and cyclooxyganase-2 in the hippocampus. These results suggest that WCW has therapeutic potential to suppress KA-induced pathogenesis in the brain by inhibiting inflammation.
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Affiliation(s)
- Jong Hee Choi
- 1 Department of Convergence Medical Science, College of Korean Medicine, Kyung Hee University , Seoul, Republic of Korea.,2 Brain Korea 21 Plus Program, College of Korean Medicine, Kyung Hee University , Seoul, Republic of Korea
| | - Minhee Jang
- 1 Department of Convergence Medical Science, College of Korean Medicine, Kyung Hee University , Seoul, Republic of Korea
| | - Eun-Jeong Kim
- 1 Department of Convergence Medical Science, College of Korean Medicine, Kyung Hee University , Seoul, Republic of Korea.,2 Brain Korea 21 Plus Program, College of Korean Medicine, Kyung Hee University , Seoul, Republic of Korea
| | - Hocheol Kim
- 2 Brain Korea 21 Plus Program, College of Korean Medicine, Kyung Hee University , Seoul, Republic of Korea.,3 Department of Herbology, College of Korean Medicine, Kyung Hee University , Seoul, Republic of Korea.,4 Institute of Korean Medicine, College of Korean Medicine, Kyung Hee University , Seoul, Republic of Korea
| | - Sang-Kyu Ye
- 5 Department of Pharmacology, Seoul National University College of Medicine , Seoul, Republic of Korea
| | - Ik-Hyun Cho
- 1 Department of Convergence Medical Science, College of Korean Medicine, Kyung Hee University , Seoul, Republic of Korea.,2 Brain Korea 21 Plus Program, College of Korean Medicine, Kyung Hee University , Seoul, Republic of Korea.,4 Institute of Korean Medicine, College of Korean Medicine, Kyung Hee University , Seoul, Republic of Korea
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Kainic Acid-Induced Excitotoxicity Experimental Model: Protective Merits of Natural Products and Plant Extracts. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2015; 2015:972623. [PMID: 26793262 PMCID: PMC4697086 DOI: 10.1155/2015/972623] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 11/16/2015] [Accepted: 11/17/2015] [Indexed: 11/17/2022]
Abstract
Excitotoxicity is well recognized as a major pathological process of neuronal death in neurodegenerative diseases involving the central nervous system (CNS). In the animal models of neurodegeneration, excitotoxicity is commonly induced experimentally by chemical convulsants, particularly kainic acid (KA). KA-induced excitotoxicity in rodent models has been shown to result in seizures, behavioral changes, oxidative stress, glial activation, inflammatory mediator production, endoplasmic reticulum stress, mitochondrial dysfunction, and selective neurodegeneration in the brain upon KA administration. Recently, there is an emerging trend to search for natural sources to combat against excitotoxicity-associated neurodegenerative diseases. Natural products and plant extracts had attracted a considerable amount of attention because of their reported beneficial effects on the CNS, particularly their neuroprotective effect against excitotoxicity. They provide significant reduction and/or protection against the development and progression of acute and chronic neurodegeneration. This indicates that natural products and plants extracts may be useful in protecting against excitotoxicity-associated neurodegeneration. Thus, targeting of multiple pathways simultaneously may be the strategy to maximize the neuroprotection effect. This review summarizes the mechanisms involved in KA-induced excitotoxicity and attempts to collate the various researches related to the protective effect of natural products and plant extracts in the KA model of neurodegeneration.
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26
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Yoon H, Jang YH, Kim SJ, Lee SJ, Kim SK. Toll-like Receptor 2 is Dispensable for an Immediate-early Microglial Reaction to Two-photon Laser-induced Cortical Injury In vivo. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2015; 19:461-5. [PMID: 26330759 PMCID: PMC4553406 DOI: 10.4196/kjpp.2015.19.5.461] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 07/09/2015] [Accepted: 07/22/2015] [Indexed: 12/27/2022]
Abstract
Microglia, the resident macrophages in the central nervous system, can rapidly respond to pathological insults. Toll-like receptor 2 (TLR2) is a pattern recognition receptor that plays a fundamental role in pathogen recognition and activation of innate immunity. Although many previous studies have suggested that TLR2 contributes to microglial activation and subsequent pathogenesis following brain tissue injury, it is still unclear whether TLR2 has a role in microglia dynamics in the resting state or in immediate-early reaction to the injury in vivo. By using in vivo two-photon microscopy imaging and Cx3cr1GFP/+ mouse line, we first monitored the motility of microglial processes (i.e. the rate of extension and retraction) in the somatosensory cortex of living TLR2-KO and WT mice; Microglial processes in TLR2-KO mice show the similar motility to that of WT mice. We further found that microglia rapidly extend their processes to the site of local tissue injury induced by a two-photon laser ablation and that such microglial response to the brain injury was similar between WT and TLR2-KO mice. These results indicate that there are no differences in the behavior of microglial processes between TLR2-KO mice and WT mice when microglia is in the resting state or encounters local injury. Thus, TLR2 might not be essential for immediate-early microglial response to brain tissue injury in vivo.
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Affiliation(s)
- Heera Yoon
- Department of Physiology, College of Korean Medicine, Kyung Hee University, Seoul 130-701, Korea
| | - Yong Ho Jang
- Department of Oral Physiology and Neuroscience, School of Dentistry, Seoul National University, Seoul 110-749, Korea
| | - Sang Jeong Kim
- Department of Physiology, School of Medicine, Seoul National University, Seoul 110-799, Korea
| | - Sung Joong Lee
- Department of Oral Physiology and Neuroscience, School of Dentistry, Seoul National University, Seoul 110-749, Korea
| | - Sun Kwang Kim
- Department of Physiology, College of Korean Medicine, Kyung Hee University, Seoul 130-701, Korea
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Abstract
Organotypic hippocampal slice cultures (OHSCs) have been used as a powerful ex vivo model for decades. They have been used successfully in studies of neuronal death, microglial activation, mossy fiber regeneration, neurogenesis, and drug screening. As a pre-animal experimental phase for physiologic and pathologic brain research, OHSCs offer outcomes that are relatively closer to those of whole-animal studies than outcomes obtained from cell culture in vitro. At the same time, mechanisms can be studied more precisely in OHSCs than they can be in vivo. Here, we summarize stroke and traumatic brain injury research that has been carried out in OHSCs and review classic experimental applications of OHSCs and its limitations.
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Jang M, Cho IH. Sulforaphane Ameliorates 3-Nitropropionic Acid-Induced Striatal Toxicity by Activating the Keap1-Nrf2-ARE Pathway and Inhibiting the MAPKs and NF-κB Pathways. Mol Neurobiol 2015; 53:2619-35. [PMID: 26096705 DOI: 10.1007/s12035-015-9230-2] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 05/22/2015] [Indexed: 02/08/2023]
Abstract
The potential neuroprotective value of sulforaphane (SFN) in Huntington's disease (HD) has not been established yet. We investigated whether SFN prevents and improves the neurological impairment and striatal cell death in a 3-nitropropionic acid (3-NP)-induced mouse model of HD. SFN (2.5 and 5.0 mg/kg/day, i.p.) was given daily 30 min before 3-NP treatment (pretreatment) and from onset/progression/peak points of the neurological scores. Pretreatment with SFN (5.0 mg/kg/day) produced the best neuroprotective effect with respect to the neurological scores and lethality among other conditions. The protective effects due to pretreatment with SFN were associated with the following: suppression of the formation of a lesion area, neuronal death, succinate dehydrogenase activity, apoptosis, microglial activation, and mRNA or protein expression of inflammatory mediators, including tumor necrosis factor-alpha, interleukin (IL)-1β, IL-6, inducible nitric oxide synthase, and cyclooxygenase-2 in the striatum after 3-NP treatment. Also, pretreatment with SFN activated the Kelch-like ECH-associated protein 1 (Keap1)-nuclear factor erythroid 2-related factor 2 (Nrf2)-antioxidant response element (ARE) pathway and inhibited the mitogen-activated protein kinases (MAPKs) and nuclear factor-kappa B (NF-κB) pathways in the striatum after 3-NP treatment. As expected, the pretreatment with activators (dimethyl fumarate and antioxidant response element inducer-3) of the Keap1-Nrf2-ARE pathway decreased the neurological impairment and lethality after 3-NP treatment. Our findings suggest that SFN may effectively attenuate 3-NP-induced striatal toxicity by activating the Keap1-Nrf2-ARE pathway and inhibiting the MAPKs and NF-κB pathways and that SFN has a wide therapeutic time-window for HD-like symptoms.
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Affiliation(s)
- Minhee Jang
- Department of Convergence Medical Science, College of Oriental Medicine, Kyung Hee University, Seoul, 130-701, Republic of Korea.,Department of Cancer Preventive Material Development, College of Oriental Medicine, Kyung Hee University, Seoul, 130-701, Republic of Korea
| | - Ik-Hyun Cho
- Department of Convergence Medical Science, College of Oriental Medicine, Kyung Hee University, Seoul, 130-701, Republic of Korea. .,Brain Korea 21 Plus Program, College of Oriental Medicine, Kyung Hee University, Seoul, 130-701, Republic of Korea. .,Institute of Korean Medicine, College of Oriental Medicine, Kyung Hee University, Seoul, 130-701, Republic of Korea.
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29
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TLR1 expression in mouse brain was increased in a KA-induced seizure model. Inflamm Res 2015; 64:487-95. [PMID: 26021825 DOI: 10.1007/s00011-015-0828-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2015] [Revised: 04/16/2015] [Accepted: 04/23/2015] [Indexed: 12/27/2022] Open
Abstract
OBJECTIVE Toll-like receptors (TLRs) that mediate inflammatory responses play an important role in epilepsy; however, whether TLR1 is also involved in epileptogenesis remains unclear. Thus, in this study, we investigated the extent and pattern of TLR1 expression in epileptic tissues. METHODS One-hundred and thirty-two mice were intra-cerebroventricularly injected with PBS or kainic acid (KA) and were examined at 1, 3, 8 and 24 h. The expression pattern and distribution of TLR1 were examined by reverse-transcriptase polymerase chain reaction (RT-PCR), western blot analysis and immunohistochemistry staining. RESULTS The mRNA and protein levels of TLR1 were significantly upregulated in the hippocampus and temporal cortex of epileptic mice compared with those of controls. TLR1 expression was increased as early as 1 h following KA treatment and peaked at 8 and 24 h. Immunohistochemistry staining demonstrated that TLR1 was distributed in the CA1-3, dentate gyrus and hilus regions of the hippocampus and different cortical regions. Immunofluorescent staining further revealed that TLR1 was primarily expressed in the neurons, microglia, and astrocytes of epileptogenic tissue. SIGNIFICANCE These results demonstrate that cortical and hippocampal sub-regional expression of TLR1 is altered during epileptogenesis in a time- and location-specific manner, suggesting a close association with the process of epilepsy.
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Larochelle A, Bellavance MA, Rivest S. Role of adaptor protein MyD88 in TLR-mediated preconditioning and neuroprotection after acute excitotoxicity. Brain Behav Immun 2015; 46:221-31. [PMID: 25733102 DOI: 10.1016/j.bbi.2015.02.019] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 02/03/2015] [Accepted: 02/20/2015] [Indexed: 12/18/2022] Open
Abstract
Excitotoxic cell death is a crucial mechanism through which neurodegeneration occurs in numerous pathologies of the central nervous system (CNS), such as Alzheimer's disease, stroke and spinal cord injury. Toll-like receptors (TLRs) are strongly expressed on microglial cells and are key regulators of the innate immune response to neuronal damage. However, it is still unclear whether their stimulation is protective or harmful in excitotoxic contexts. In this study, we demonstrate that systemic administration of lipopolysaccharide (LPS) or Pam3CSK4 24h prior to an intrastriatal injection of kainic acid (KA) significantly protected cortical neurons in the acute phase of injury. Protection could not be detected with the TLR3 ligand poly-IC. Histological analyses revealed that microglia of LPS and Pam3CSK4 pre-conditioned group were primed to react to injury and exhibited a stronger expression of Tnf and Tlr2 mRNA. We also found that mice deficient for MyD88, a critical adaptor protein for most TLR, were more vulnerable than WT mice to KA-induced excitotoxicity at early (12h and 24h) and late (10days) time points. Finally, bone-marrow chimeric mice revealed that MyD88 signaling in CNS resident cells, but not in cells of hematopoietic origin, mediates the protective effect. This study unravels the potential of TLR2 and TLR4 agonists to induce a protective state of preconditioning against KA-mediated excitotoxicity and further highlights the beneficial role of cerebral MyD88 signaling in this context.
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Affiliation(s)
- Antoine Larochelle
- Neuroscience Laboratory, CHU de Québec Research Center and Department of Molecular Medicine, Faculty of Medicine, Laval University, 2705 Laurier Blvd., Québec G1V 4G2, Canada
| | - Marc-André Bellavance
- Neuroscience Laboratory, CHU de Québec Research Center and Department of Molecular Medicine, Faculty of Medicine, Laval University, 2705 Laurier Blvd., Québec G1V 4G2, Canada
| | - Serge Rivest
- Neuroscience Laboratory, CHU de Québec Research Center and Department of Molecular Medicine, Faculty of Medicine, Laval University, 2705 Laurier Blvd., Québec G1V 4G2, Canada.
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Microglia in Glia-Neuron Co-cultures Exhibit Robust Phagocytic Activity Without Concomitant Inflammation or Cytotoxicity. Cell Mol Neurobiol 2015; 35:961-75. [PMID: 25894384 DOI: 10.1007/s10571-015-0191-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 03/28/2015] [Indexed: 12/19/2022]
Abstract
A simple method to co-culture granule neurons and glia from a single brain region is described, and microglia activation profiles are assessed in response to naturally occurring neuronal apoptosis, excitotoxin-induced neuronal death, and lipopolysaccharide (LPS) addition. Using neonatal rat cerebellar cortex as a tissue source, glial proliferation is regulated by omission or addition of the mitotic inhibitor cytosine arabinoside (AraC). After 7-8 days in vitro, microglia in AraC(-) cultures are abundant and activated based on their amoeboid morphology, expressions of ED1 and Iba1, and ability to phagocytose polystyrene beads and the majority of neurons undergoing spontaneous apoptosis. Microglia and phagocytic activities are sparse in AraC(+) cultures. Following exposure to excitotoxic kainate concentrations, microglia in AraC(-) cultures phagocytose most dead neurons within 24 h without exacerbating neuronal loss or mounting a strong or sustained inflammatory response. LPS addition induces a robust inflammatory response, based on microglial expressions of TNF-α, COX-2 and iNOS proteins, and mRNAs, whereas these markers are essentially undetectable in control cultures. Thus, the functional effector state of microglia is primed for phagocytosis but not inflammation or cytotoxicity even after kainate exposure that triggers death in the majority of neurons. This model should prove useful in studying the progressive activation states of microglia and factors that promote their conversion to inflammatory and cytotoxic phenotypes.
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32
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Lee MJ, Jang M, Choi J, Chang BS, Kim DY, Kim SH, Kwak YS, Oh S, Lee JH, Chang BJ, Nah SY, Cho IH. Korean Red Ginseng and Ginsenoside-Rb1/-Rg1 Alleviate Experimental Autoimmune Encephalomyelitis by Suppressing Th1 and Th17 Cells and Upregulating Regulatory T Cells. Mol Neurobiol 2015; 53:1977-2002. [PMID: 25846819 DOI: 10.1007/s12035-015-9131-4] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 02/22/2015] [Indexed: 11/26/2022]
Abstract
The effects of Korean red ginseng extract (KRGE) on autoimmune disorders of the nervous system are not clear. We investigated whether KRGE has a beneficial effect on acute and chronic experimental autoimmune encephalomyelitis (EAE). Pretreatment (daily from 10 days before immunization with myelin basic protein peptide) with KRGE significantly attenuated clinical signs and loss of body weight and was associated with the suppression of spinal demyelination and glial activation in acute EAE rats, while onset treatment (daily after the appearance of clinical symptoms) did not. The suppressive effect of KRGE corresponded to the messenger RNA (mRNA) expression of proinflammatory cytokines (tumor necrosis factor-α [TNF-α] and interleukin [IL]-1β), chemokines (RANTES, monocyte chemotactic protein-1 [MCP-1], and macrophage inflammatory protein-1α [MIP-1α]), adhesion molecules (intercellular adhesion molecule-1 [ICAM-1], vascular cell adhesion molecule-1 [VCAM-1], and platelet endothelial cell adhesion molecule [PECAM-1]), and inducible nitric oxide synthase in the spinal cord after immunization. Interestingly, in acute EAE rats, pretreatment with KRGE significantly reduced the population of CD4(+), CD4(+)/IFN-γ(+), and CD4(+)/IL-17(+) T cells in the spinal cord and lymph nodes, corresponding to the downregulation of mRNA expression of IFN-γ, IL-17, and IL-23 in the spinal cord. On the other hand, KRGE pretreatment increased the population of CD4(+)/Foxp3(+) T cells in the spinal cord and lymph nodes of these rats, corresponding to the upregulation of mRNA expression of Foxp3 in the spinal cord. Interestingly, intrathecal pretreatment of rats with ginsenosides (Rg1 and Rb1) significantly decreased behavioral impairment. These results strongly indicate that KRGE has a beneficial effect on the development and progression of EAE by suppressing T helper 1 (Th1) and Th17 T cells and upregulating regulatory T cells. Additionally, pre- and onset treatment with KRGE alleviated neurological impairment of myelin oligodendrocyte glycoprotein(35-55)-induced mouse model of chronic EAE. These results warrant further investigation of KRGE as preventive or therapeutic strategies for autoimmune disorders, such as multiple sclerosis.
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MESH Headings
- Animals
- Blood-Brain Barrier/drug effects
- Blood-Brain Barrier/pathology
- Chemokines/metabolism
- Chronic Disease
- Demyelinating Diseases/complications
- Demyelinating Diseases/drug therapy
- Demyelinating Diseases/pathology
- Encephalomyelitis, Autoimmune, Experimental/drug therapy
- Encephalomyelitis, Autoimmune, Experimental/immunology
- Female
- Fibronectins/metabolism
- Ginsenosides/pharmacology
- Ginsenosides/therapeutic use
- Inflammation/complications
- Inflammation/drug therapy
- Inflammation/pathology
- Macrophages/drug effects
- Macrophages/metabolism
- Macrophages/pathology
- Mice, Inbred C57BL
- Neuroglia/drug effects
- Neuroglia/metabolism
- Neuroglia/pathology
- Panax/chemistry
- Plant Extracts/pharmacology
- Plant Extracts/therapeutic use
- Platelet Endothelial Cell Adhesion Molecule-1/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats, Inbred Lew
- Spinal Cord/drug effects
- Spinal Cord/pathology
- T-Lymphocytes, Regulatory/drug effects
- T-Lymphocytes, Regulatory/immunology
- Th1 Cells/drug effects
- Th1 Cells/immunology
- Th17 Cells/drug effects
- Th17 Cells/immunology
- Up-Regulation/drug effects
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Affiliation(s)
- Min Jung Lee
- Department of Cancer Preventive Material Development, College of Korean Medicine, Kyung Hee University, Seoul, 130-701, Republic of Korea
- Department of Convergence Medical Sciences, College of Korean Medicine, Kyung Hee University, Seoul, 130-701, Republic of Korea
| | - Minhee Jang
- Department of Cancer Preventive Material Development, College of Korean Medicine, Kyung Hee University, Seoul, 130-701, Republic of Korea
- Department of Convergence Medical Sciences, College of Korean Medicine, Kyung Hee University, Seoul, 130-701, Republic of Korea
| | - Jonghee Choi
- Department of Convergence Medical Sciences, College of Korean Medicine, Kyung Hee University, Seoul, 130-701, Republic of Korea
- Brain Korea 21 Plus Program, Kyung Hee University, Seoul, 130-701, Republic of Korea
| | - Byung Soo Chang
- Department of Cosmetology, Hanseo University, Seosan, 356-706, Republic of Korea
| | - Do Young Kim
- Barrow Neurological Institute and St. Joseph's Medical Center, Phoenix, AZ, 85013, USA
| | - Sung-Hoon Kim
- Department of Cancer Preventive Material Development, College of Korean Medicine, Kyung Hee University, Seoul, 130-701, Republic of Korea
| | - Yi-Seong Kwak
- Central Research Institute, Korea Ginseng Corporation, Daejeon, 305-805, Republic of Korea
| | - Seikwan Oh
- Department of Neuroscience and Tissue Injury Defense Research Center, School of Medicine, Ewha Womans University, Seoul, 158-710, Republic of Korea
| | - Jong-Hwan Lee
- Department of Veterinary Anatomy, College of Veterinary Medicine, Konkuk University, Seoul, 143-701, Republic of Korea
| | - Byung-Joon Chang
- Department of Veterinary Anatomy, College of Veterinary Medicine, Konkuk University, Seoul, 143-701, Republic of Korea
| | - Seung-Yeol Nah
- Ginsentology Research Laboratory and Department of Physiology, College of Veterinary Medicine and Bio/Molecular Informatics Center, Konkuk University, Seoul, 143-701, Republic of Korea
| | - Ik-Hyun Cho
- Department of Convergence Medical Sciences, College of Korean Medicine, Kyung Hee University, Seoul, 130-701, Republic of Korea.
- Institute of Korean Medicine, Kyung Hee University, Seoul, 130-701, Republic of Korea.
- Brain Korea 21 Plus Program, Kyung Hee University, Seoul, 130-701, Republic of Korea.
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Arsenault D, Drouin-Ouellet J, Saint-Pierre M, Petrou P, Dubois M, Kriz J, Barker RA, Cicchetti A, Cicchetti F. A novel combinational approach of microstimulation and bioluminescence imaging to study the mechanisms of action of cerebral electrical stimulation in mice. J Physiol 2015; 593:2257-78. [PMID: 25653107 DOI: 10.1113/jphysiol.2014.287243] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 01/30/2015] [Indexed: 12/12/2022] Open
Abstract
Deep brain stimulation (DBS) is used to treat a number of neurological conditions and is currently being tested to intervene in neuropsychiatric conditions. However, a better understanding of how it works would ensure that side effects could be minimized and benefits optimized. We have thus developed a unique device to perform brain stimulation (BS) in mice and to address fundamental issues related to this methodology in the pre-clinical setting. This new microstimulator prototype was specifically designed to allow simultaneous live bioluminescence imaging of the mouse brain, allowing real time assessment of the impact of stimulation on cerebral tissue. We validated the authenticity of this tool in vivo by analysing the expression of toll-like receptor 2 (TLR2), corresponding to the microglial response, in the stimulated brain regions of TLR2-fluc-GFP transgenic mice, which we further corroborated with post-mortem analyses in these animals as well as in human brains of patients who underwent DBS to treat their Parkinson's disease. In the present study, we report on the development of the first BS device that allows for simultaneous live in vivo imaging in mice. This tool opens up a whole new range of possibilities that allow a better understanding of BS and how to optimize its effects through its use in murine models of disease.
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Affiliation(s)
- Dany Arsenault
- Centre de Recherche du CHU de Québec (CHUQ), Axe Neurosciences, Québec, QC, Canada
| | - Janelle Drouin-Ouellet
- John van Geest Centre for Brain Repair, Department of Clinical Neuroscience, University of Cambridge, Cambridge, UK
| | - Martine Saint-Pierre
- Centre de Recherche du CHU de Québec (CHUQ), Axe Neurosciences, Québec, QC, Canada
| | - Petros Petrou
- Centre de Recherche du CHU de Québec (CHUQ), Axe Neurosciences, Québec, QC, Canada
| | - Marilyn Dubois
- Centre de Recherche du CHU de Québec (CHUQ), Axe Neurosciences, Québec, QC, Canada
| | - Jasna Kriz
- Département de Psychiatrie et Neurosciences, Université Laval, Québec, QC, Canada.,Institut Universitaire en Santé Mentale de Québec, Québec, QC, Canada
| | - Roger A Barker
- John van Geest Centre for Brain Repair, Department of Clinical Neuroscience, University of Cambridge, Cambridge, UK
| | - Antonio Cicchetti
- Centre de Recherche du CHU de Québec (CHUQ), Axe Neurosciences, Québec, QC, Canada
| | - Francesca Cicchetti
- Centre de Recherche du CHU de Québec (CHUQ), Axe Neurosciences, Québec, QC, Canada.,Département de Psychiatrie et Neurosciences, Université Laval, Québec, QC, Canada
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Lee JY, Kang SR, Yune TY. Fluoxetine prevents oligodendrocyte cell death by inhibiting microglia activation after spinal cord injury. J Neurotrauma 2015; 32:633-44. [PMID: 25366938 DOI: 10.1089/neu.2014.3527] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Oligodendrocyte cell death and axon demyelination after spinal cord injury (SCI) are known to be important secondary injuries contributing to permanent neurological disability. Thus, blocking oligodendrocyte cell death should be considered for therapeutic intervention after SCI. Here, we demonstrated that fluoxetine, an antidepressant drug, alleviates oligodendrocyte cell death by inhibiting microglia activation after SCI. After injury at the T9 level with a Precision Systems and Instrumentation (Lexington, KY) device, fluoxetine (10 mg/kg, intraperitoneal) was administered once a day for the indicated time points. Immunostaining with CD11b (OX-42) antibody and quantification analysis showed that microglia activation was significantly inhibited by fluoxetine at 5 days after injury. Fluoxetine also significantly inhibited activation of p38 mitogen-activated protein kinase (p38-MAPK) and expression of pro-nerve growth factor (pro-NGF), which is known to mediate oligodendrocyte cell death through the p75 neurotrophin receptor after SCI. In addition, fluoxetine attenuated activation of Ras homolog gene family member A and decreased the level of phosphorylated c-Jun and, ultimately, alleviated caspase-3 activation and significantly reduced cell death of oligodendrocytes at 5 days after SCI. Further, the decrease of myelin basic protein, myelin loss, and axon loss in white matter was also significantly blocked by fluoxetine, as compared to vehicle control. These results suggest that fluoxetine inhibits oligodendrocyte cell death by inhibiting microglia activation and p38-MAPK activation, followed by pro-NGF production after SCI, and provide a potential usage of fluoxetine for a therapeutic agent after acute SCI in humans.
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Affiliation(s)
- Jee Y Lee
- 1 Age-Related and Brain Diseases Research Center, Kyung Hee University , Seoul, Korea
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35
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Bee Venom Acupuncture Alleviates Experimental Autoimmune Encephalomyelitis by Upregulating Regulatory T Cells and Suppressing Th1 and Th17 Responses. Mol Neurobiol 2015; 53:1419-1445. [DOI: 10.1007/s12035-014-9012-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 11/18/2014] [Indexed: 12/27/2022]
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36
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Lee JY, Choi HY, Ahn HJ, Ju BG, Yune TY. Matrix metalloproteinase-3 promotes early blood-spinal cord barrier disruption and hemorrhage and impairs long-term neurological recovery after spinal cord injury. THE AMERICAN JOURNAL OF PATHOLOGY 2014; 184:2985-3000. [PMID: 25325922 DOI: 10.1016/j.ajpath.2014.07.016] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 06/21/2014] [Accepted: 07/15/2014] [Indexed: 11/16/2022]
Abstract
After spinal cord injury (SCI), blood-spinal cord barrier (BSCB) disruption by matrix metalloproteinases (MMPs) leads to BSCB permeability and blood cell infiltration, contributing to permanent neurological disability. Herein, we report that MMP-3 plays a critical role in BSCB disruption after SCI in mice. MMP-3 was induced in infiltrated neutrophils and blood vessels after SCI, and NF-κB as a transcription factor was involved in MMP-3 expression. BSCB permeability and blood cell infiltration after injury were more reduced in Mmp3 knockout (KO) mice than in wild-type (WT) mice, which was significantly inhibited by Mmp3 siRNA or a general inhibitor of MMPs, N-isobutyl-N-(4-methoxyphenylsulfonyl)glycyl hydroxamic acid. The level of tight junction proteins, such as occludin and zonula occludens-1, which decreased after SCI, was also higher in Mmp3 KO than in WT mice. Exogenously, MMP-3 injection into the normal spinal cord also induced BSCB permeability. Furthermore, MMP-9 activation after injury was mediated by MMP-3 activation. Finally, improved functional recovery was observed in Mmp3 KO mice compared with WT mice after injury. These results demonstrated the role of MMP-3 in BSCB disruption after SCI for the first time and suggest that the regulation of MMP-3 can be considered a therapeutic target to inhibit BSCB disruption and hemorrhage, and thereby enhance functional recovery after acute SCI.
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Affiliation(s)
- Jee Youn Lee
- Age-Related and Brain Diseases Research Center, School of Medicine, Kyung Hee University, Seoul, Republic of Korea; Neurodegeneration Control Research Center, School of Medicine, Kyung Hee University, Seoul, Republic of Korea
| | - Hae Young Choi
- Age-Related and Brain Diseases Research Center, School of Medicine, Kyung Hee University, Seoul, Republic of Korea; Neurodegeneration Control Research Center, School of Medicine, Kyung Hee University, Seoul, Republic of Korea
| | - Hyun-Jong Ahn
- Department of Microbiology, School of Medicine, Kyung Hee University, Seoul, Republic of Korea
| | - Bong Gun Ju
- Department of Life Science, Sogang University, Seoul, Republic of Korea
| | - Tae Young Yune
- Age-Related and Brain Diseases Research Center, School of Medicine, Kyung Hee University, Seoul, Republic of Korea; Neurodegeneration Control Research Center, School of Medicine, Kyung Hee University, Seoul, Republic of Korea; Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul, Republic of Korea.
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Jo S, Yarishkin O, Hwang YJ, Chun YE, Park M, Woo DH, Bae JY, Kim T, Lee J, Chun H, Park HJ, Lee DY, Hong J, Kim HY, Oh SJ, Park SJ, Lee H, Yoon BE, Kim Y, Jeong Y, Shim I, Bae YC, Cho J, Kowall NW, Ryu H, Hwang E, Kim D, Lee CJ. GABA from reactive astrocytes impairs memory in mouse models of Alzheimer's disease. Nat Med 2014; 20:886-96. [PMID: 24973918 DOI: 10.1038/nm.3639] [Citation(s) in RCA: 526] [Impact Index Per Article: 52.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Accepted: 06/23/2014] [Indexed: 12/11/2022]
Abstract
In Alzheimer's disease (AD), memory impairment is the most prominent feature that afflicts patients and their families. Although reactive astrocytes have been observed around amyloid plaques since the disease was first described, their role in memory impairment has been poorly understood. Here, we show that reactive astrocytes aberrantly and abundantly produce the inhibitory gliotransmitter GABA by monoamine oxidase-B (Maob) and abnormally release GABA through the bestrophin 1 channel. In the dentate gyrus of mouse models of AD, the released GABA reduces spike probability of granule cells by acting on presynaptic GABA receptors. Suppressing GABA production or release from reactive astrocytes fully restores the impaired spike probability, synaptic plasticity, and learning and memory in the mice. In the postmortem brain of individuals with AD, astrocytic GABA and MAOB are significantly upregulated. We propose that selective inhibition of astrocytic GABA synthesis or release may serve as an effective therapeutic strategy for treating memory impairment in AD.
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Affiliation(s)
- Seonmi Jo
- 1] Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea. [2] WCI Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea. [3]
| | - Oleg Yarishkin
- 1] WCI Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea. [2]
| | - Yu Jin Hwang
- Center for Neuro-Medicine, Brain Science Institute, KIST, Seoul, Republic of Korea
| | - Ye Eun Chun
- 1] WCI Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea. [2] Neuroscience Program, Korea University of Science and Technology, Daejeon, Republic of Korea
| | - Mijeong Park
- 1] Neuroscience Program, Korea University of Science and Technology, Daejeon, Republic of Korea. [2] Center for Neuroscience, Brain Science Institute, KIST, Seoul, Republic of Korea
| | - Dong Ho Woo
- WCI Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
| | - Jin Young Bae
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea
| | - Taekeun Kim
- WCI Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
| | - Jaekwang Lee
- WCI Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
| | - Heejung Chun
- WCI Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
| | - Hyun Jung Park
- Department of Science in Korean Medicine, Graduate School, College of Korean Medicine, Kyung Hee University, Seoul, Republic of Korea
| | - Da Yong Lee
- WCI Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
| | - Jinpyo Hong
- WCI Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
| | - Hye Yun Kim
- Center for Neuro-Medicine, Brain Science Institute, KIST, Seoul, Republic of Korea
| | - Soo-Jin Oh
- Center for Neuroscience, Brain Science Institute, KIST, Seoul, Republic of Korea
| | - Seung Ju Park
- WCI Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
| | - Hyo Lee
- WCI Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
| | - Bo-Eun Yoon
- WCI Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
| | - YoungSoo Kim
- Center for Neuro-Medicine, Brain Science Institute, KIST, Seoul, Republic of Korea
| | - Yong Jeong
- Department of Bio and Brain Engineering, KAIST, Daejeon, Republic of Korea
| | - Insop Shim
- Department of Science in Korean Medicine, Graduate School, College of Korean Medicine, Kyung Hee University, Seoul, Republic of Korea
| | - Yong Chul Bae
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea
| | - Jeiwon Cho
- 1] Neuroscience Program, Korea University of Science and Technology, Daejeon, Republic of Korea. [2] Center for Neuroscience, Brain Science Institute, KIST, Seoul, Republic of Korea
| | - Neil W Kowall
- 1] Boston University Alzheimer's Disease Center, Boston University School of Medicine, Boston, Massachusetts, USA. [2] Department of Neurology, Boston University School of Medicine, Boston, Massachusetts, USA. [3] VA Boston Healthcare System, Boston, Massachusetts, USA
| | - Hoon Ryu
- 1] Center for Neuro-Medicine, Brain Science Institute, KIST, Seoul, Republic of Korea. [2] Boston University Alzheimer's Disease Center, Boston University School of Medicine, Boston, Massachusetts, USA. [3] Department of Neurology, Boston University School of Medicine, Boston, Massachusetts, USA. [4] VA Boston Healthcare System, Boston, Massachusetts, USA
| | - Eunmi Hwang
- WCI Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
| | - Daesoo Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - C Justin Lee
- 1] WCI Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea. [2] Neuroscience Program, Korea University of Science and Technology, Daejeon, Republic of Korea. [3] Center for Neuroscience, Brain Science Institute, KIST, Seoul, Republic of Korea. [4] KU-KIST Graduate School of Converging Science of Technology, Korea University, Seoul, Republic of Korea
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38
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Xu K, Zhang Y, Wang Y, Ling P, Xie X, Jiang C, Zhang Z, Lian XY. Ginseng Rb fraction protects glia, neurons and cognitive function in a rat model of neurodegeneration. PLoS One 2014; 9:e101077. [PMID: 24971630 PMCID: PMC4074135 DOI: 10.1371/journal.pone.0101077] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 06/03/2014] [Indexed: 11/18/2022] Open
Abstract
The loss and injury of neurons play an important role in the onset of various neurodegenerative diseases, while both microgliosis and astrocyte loss or dysfunction are significant causes of neuronal degeneration. Previous studies have suggested that an extract enriched panaxadiol saponins from ginseng has more neuroprotective potential than the total saponins of ginseng. The present study investigated whether a fraction of highly purified panaxadiol saponins (termed as Rb fraction) was protective for both glia and neurons, especially GABAergic interneurons, against kainic acid (KA)-induced excitotoxicity in rats. Rats received Rb fraction at 30 mg/kg (i.p.), 40 mg/kg (i.p. or saline followed 40 min later by an intracerebroventricular injection of KA. Acute hippocampal injury was determined at 48 h after KA, and impairment of hippocampus-dependent learning and memory as well as delayed neuronal injury was determined 16 to 21 days later. KA injection produced significant acute hippocampal injuries, including GAD67-positive GABAergic interneuron loss in CA1, paralbumin (PV)-positive GABAergic interneuron loss, pyramidal neuron degeneration and astrocyte damage accompanied with reactive microglia in both CA1 and CA3 regions of the hippocampus. There was also a delayed loss of GAD67-positive interneurons in CA1, CA3, hilus and dentate gyrus. Microgliosis also became more severe 21 days later. Accordingly, KA injection resulted in hippocampus-dependent spatial memory impairment. Interestingly, the pretreatment with Rb fraction at 30 or 40 mg/kg significantly protected the pyramidal neurons and GABAergic interneurons against KA-induced acute excitotoxicity and delayed injury. Rb fraction also prevented memory impairments and protected astrocytes from KA-induced acute excitotoxicity. Additionally, microglial activation, especially the delayed microgliosis, was inhibited by Rb fraction. Overall, this study demonstrated that Rb fraction protected both astrocytes and neurons, especially GABAergic interneurons, and maintained microglial homeostasis against KA-induced excitotoxicity. Therefore, Rb fraction has the potential to prevent and treat neurodegenerative diseases.
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Affiliation(s)
- Kangning Xu
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Yufen Zhang
- Anhui University of Chinese Medicine, Hefei, China
| | - Yan Wang
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Peng Ling
- Anhui University of Chinese Medicine, Hefei, China
| | - Xin Xie
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Chenyao Jiang
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Zhizhen Zhang
- Ocean College, Zhejiang University, Hangzhou, China
- * E-mail: (XYL); (ZZZ)
| | - Xiao-Yuan Lian
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
- * E-mail: (XYL); (ZZZ)
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Hayward JH, Lee SJ. A Decade of Research on TLR2 Discovering Its Pivotal Role in Glial Activation and Neuroinflammation in Neurodegenerative Diseases. Exp Neurobiol 2014; 23:138-47. [PMID: 24963278 PMCID: PMC4065827 DOI: 10.5607/en.2014.23.2.138] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 05/21/2014] [Accepted: 05/23/2014] [Indexed: 02/07/2023] Open
Abstract
Toll-like receptors (TLRs) belong to a class of pattern recognition receptors that play an important role in host defense against pathogens. TLRs on innate immune cells recognize a wide variety of pathogen-associated molecular patterns (PAMPs) and trigger innate immune responses. Later, it was revealed that the same receptors are also utilized to detect tissue damage to trigger inflammatory responses in the context of non-infectious inflammation. In the nervous system, different members of the TLR family are expressed on glial cells including astrocytes, microglia, oligodendrocytes, and Schwann cells, implicating their putative role in innate/inflammatory responses in the nervous system. In this regard, we have investigated the function of TLRs in neuroinflammation. We discovered that a specific member of the TLR family, namely TLR2, functions as a master sentry receptor to detect neuronal cell death and tissue damage in many different neurological conditions including nerve transection injury, intracerebral hemorrhage, traumatic brain injury, and hippocampal excitotoxicity. In this review, we have summarized our research for the last decade on the role of TLR2 in neuroinflammation in the above neurological disorders. Our data suggest that TLR2 can be an efficient target to regulate unwanted inflammatory response in these neurological conditions.
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Affiliation(s)
- Jin Hee Hayward
- Department of Neuroscience and Physiology of School of Dentistry, and Interdisciplinary Program in Genetic Engineering, Seoul National University, Seoul 110-749, Korea
| | - Sung Joong Lee
- Department of Neuroscience and Physiology of School of Dentistry, and Interdisciplinary Program in Genetic Engineering, Seoul National University, Seoul 110-749, Korea
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40
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Pitter KL, Tamagno I, Feng X, Ghosal K, Amankulor N, Holland EC, Hambardzumyan D. The SHH/Gli pathway is reactivated in reactive glia and drives proliferation in response to neurodegeneration-induced lesions. Glia 2014; 62:1595-607. [PMID: 24895267 DOI: 10.1002/glia.22702] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2014] [Revised: 05/14/2014] [Accepted: 05/19/2014] [Indexed: 12/29/2022]
Abstract
In response to neurodegeneration, the adult mammalian brain activates a cellular cascade that results in reactive astrogliosis and microgliosis. The mechanism through which astrocytes become reactive and the physiological consequences of their activation in response to neurodegeneration is complex. While the activation and proliferation of astrocytes has been shown to occur during massive neuronal cell death, the functional relationship between these two events has not been clearly elucidated. Here we show that in response to kainic acid- (KA) induced neurodegeneration, the mitogen sonic hedgehog (SHH) is upregulated in reactive astrocytes. SHH activity peaks at 7 days and is accompanied by increased Gli activity and elevated proliferation in several cell types. To determine the functional role of SHH-Gli signaling following KA lesions, we used a pharmacological approach to show that SHH secreted by astrocytes drives the activation and proliferation of astrocytes and microglia. The consequences of SHH-Gli signaling in KA-induced lesions appear to be independent of the severity of neurodegeneration.
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Affiliation(s)
- Kenneth L Pitter
- Department of Cancer Biology and Genetics, Memorial Sloan-Kettering Cancer Center, New York, New York; The Brain Tumor Center, Memorial Sloan-Kettering Cancer Center, New York, New York
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41
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Suh EC, Jung YJ, Kim YA, Park EM, Lee SJ, Lee KE. Knockout of Toll-like receptor 2 attenuates Aβ25-35-induced neurotoxicity in organotypic hippocampal slice cultures. Neurochem Int 2013; 63:818-25. [PMID: 24161618 DOI: 10.1016/j.neuint.2013.10.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Revised: 09/13/2013] [Accepted: 10/15/2013] [Indexed: 12/21/2022]
Abstract
Toll-like receptors (TLRs), which have been implicated in various neuroinflammatory responses, are thought to act in defense mechanisms by inhibiting neuronal cell death in Alzheimer's disease. In this study, we evaluated the effects of TLR2 on amyloid beta peptide 25-35 (Aβ25-35)-induced neuronal cell death, synaptic dysfunction, and microglial activation in organotypic hippocampal slice cultures (OHSCs) from wild-type (WT) C57BL/6 mice and TLR2-knockout (KO) mice. In WT mice, Aβ25-35 induced β-amyloid aggregation and surrounding TLR2 expression. And, propidium iodide (PI) uptake, which is a measure of cell death, increased in a dose-dependent manner in slices with Aβ25-35 treatment. In the Aβ25-35-treated TLR2-KO OHSCs, the PI uptake was significantly attenuated to the control level, indicating that the cells were less susceptible to Aβ25-35-induced neuronal toxicity. In the ultrastructural analysis, nuclear shrinkage, slightly swollen mitochondria, and degraded organelles were detected in the Aβ25-35-treated slices from WT mice but not in the Aβ25-35-treated slices from TLR2-KO, suggesting the resistance of TLR2-KO to Aβ25-35-induced neurotoxicity. In Aβ25-35-treated OHSCs of WT mice, the levels of phosphorylated tau were increased and the levels of synaptophysin were decreased in a dose-dependent manner, but they were not changed in OHSCs of TLR2-KO mice. In WT mice, Aβ25-35 increased total protein level and immunoreactivity of Iba-1, which was colocalized with TLR2. However, there were no significant changes in the slices of Aβ25-35-treated TLR2-KO mice. These results suggested that TLR2 may play a role in Aβ25-35-induced neuronal cell loss and synaptic dysfunction through the activation of microglia in OHSCs.
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Affiliation(s)
- Eun Cheng Suh
- Department of Pharmacology and Ewha Medical Research Institute, School of Medicine, Ewha Womans University, Seoul, South Korea
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Uccelli A. Mesenchymal stem cells exert a remarkable regenerative effect requiring minimal CNS integration. Exp Neurol 2013; 247:292-5. [DOI: 10.1016/j.expneurol.2013.01.028] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2012] [Revised: 01/22/2013] [Accepted: 01/28/2013] [Indexed: 12/28/2022]
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Fernandez-Lizarbe S, Montesinos J, Guerri C. Ethanol induces TLR4/TLR2 association, triggering an inflammatory response in microglial cells. J Neurochem 2013; 126:261-73. [PMID: 23600947 DOI: 10.1111/jnc.12276] [Citation(s) in RCA: 121] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 04/11/2013] [Accepted: 04/17/2013] [Indexed: 02/06/2023]
Abstract
Alcohol consumption can induce brain damage, demyelination, and neuronal death, although the mechanisms are poorly understood. Toll-like receptors are sensors of the innate immune system and their activation induces inflammatory processes. We have reported that ethanol activates and recruits Toll-like receptor (TLR)4 receptors within the lipid rafts of glial cells, triggering the production of inflammatory mediators and causing neuroinflammation. Since TLR2 can also participate in the glial response and in the neuroinflammation, we investigate the effects of ethanol on TLR4/TLR2 responses. Here, we demonstrate that ethanol up-regulates TLR4 and TLR2 expression in microglial cells, inducing the production of inflammatory mediators which triggers reactive oxygen species generation and neuronal apoptosis. Ethanol also promotes TLR4/TLR2 recruitment into lipid rafts-caveolae, mimicking their activation by their ligands, lipopolysaccharide, and lipoteichoic acid (LTA). Immunoprecipitation and confocal microscopy studies reveal that ethanol induces a physical association between TLR2 and TLR4 receptors, suggesting the formation of heterodimers. Using microglia from either TLR2 or TLR4 knockout mice, we show that TLR2 potentiates the effects of ethanol on the TLR4 response reflected by the activation of MAPKs and inducible NO synthase. In summary, we provide evidence for a mechanism by which ethanol triggers TLR4/TLR2 association contributing to the neuroinflammation and neurodegeneration associated with alcohol abuse.
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Affiliation(s)
- Sara Fernandez-Lizarbe
- Department of Cellular Pathology, Príncipe Felipe Research Centre, Eduardo Primo Yúfera, Valencia, Spain
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Association between genetic polymorphisms of Toll-like receptor 2 (TLR2) and schizophrenia in the Korean population. Gene 2013; 526:182-6. [PMID: 23644137 DOI: 10.1016/j.gene.2013.04.058] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Revised: 03/19/2013] [Accepted: 04/15/2013] [Indexed: 12/30/2022]
Abstract
Immunological dysregulation has been suggested to be involved in the pathogenesis of schizophrenia. Accumulating evidences further implicate that activated inflammatory processes may be particularly relevant for the precipitation of negative and cognitive symptoms of schizophrenia. Toll-like receptor 2 (TLR2) plays an important role in innate immunity by sensing a variety of pathogens and inducing an acquired immunity. In the present study, we investigated whether the coding region of single nucleotide polymorphisms (SNPs) of the TLR2 gene was associated with schizophrenia as well as with clinical symptoms in schizophrenia patients. The study population consisted of 286 Korean schizophrenia patients and 305 Korean control subjects. The assessment of the Scale for the Assessment of Negative Symptoms was used to evaluate the negative symptoms of schizophrenia; the operational criteria checklist was used to measure general psychopathology. We selected two cSNPs [rs3804099 (Asn199Asn) and rs3804100 (Ser450Ser)] considering their heterozygosity and minor allele frequency. SNP genotyping was conducted using direct sequencing. We did not find any significant associations between SNPs and schizophrenia in the genotype and allelic frequencies. On the other hand, in the analysis of cognitive symptoms, rs3804099 showed significant differences in schizophrenia patients with poor concentration in the dominant model (TC/CC vs. TT, p=0.0099). Also, rs3804100 showed a significant association with poor concentration in the co-dominant (TC vs. TT, p=0.014) and the dominant models (TC/CC vs. TT, p=0.0035). We obtained no significant support for the association of the TLR2 gene with susceptibility to schizophrenia in the Korean population. However, our results provide possibility that C allele of rs3804099 and rs3804100 may be associated with poor concentration in schizophrenia patients. Further studies with larger samples are required to confirm our results.
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Fisetin enhances behavioral performances and attenuates reactive gliosis and inflammation during aluminum chloride-induced neurotoxicity. Neuromolecular Med 2013; 15:192-208. [PMID: 23315010 DOI: 10.1007/s12017-012-8210-1] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2012] [Accepted: 11/29/2012] [Indexed: 10/27/2022]
Abstract
Aluminum (Al) is an environmental neurotoxin that affects cerebral functions and causes health complications. However, the role of Al in arbitrating glia homeostasis and pathophysiology remains obscure. Astrocyte, microglia activation (reactive gliosis), and associated inflammatory events play a decisive role in neurodegeneration and may represent a target for treating neurodegenerative disorders. In this study, we have analyzed the role of aluminum chloride (AlCl3) in causing reactive gliosis in the brain of mice and the ability of fisetin, a flavonoid to attenuate reactive gliosis and neuronal inflammation. Reports suggest that fisetin exerts antioxidant and anti-inflammatory actions. Fisetin at a dose of 15 mg/kg body weight was orally administered, daily (pre-treated for 4 weeks before AlCl3 induction and co-treated until experimental period of 8 weeks) to mice induced with AlCl3 (200 mg/kg b.wt./day/8 weeks, orally). Administration of AlCl3 developed behavioral deficits, triggered lipid peroxidation (LPO), compromised acetylcholine esterase (AChE) activity, and reduced the levels of superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST), and reduced glutathione (GSH), and caused histologic aberrations. These effects were accompanied by increased expressions of Glial fibrillary acidic protein and ionized calcium-binding adapter molecule 1. Pro-inflammatory cytokines, such as tumor necrosis factor alpha, interleukin-1β, inducible nitric oxide synthase, were increased upon AlCl3 administration. AlCl3-induced alterations in the activities of SOD, CAT, GST, AChE and levels of GSH, LPO, activity of AChE, behavioral deficits, histologic aberrations, reactive gliosis, and inflammatory niche were attenuated on treatment with fisetin. Collectively, our results indicate that fisetin exerts neuroprotection against AlCl3-induced brain pathology.
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Kainic acid-induced neuronal degeneration in hippocampal pyramidal neurons is driven by both intrinsic and extrinsic factors: analysis of FVB/N↔C57BL/6 chimeras. J Neurosci 2012; 32:12093-101. [PMID: 22933793 DOI: 10.1523/jneurosci.6478-11.2012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The excitotoxic effects of kainic acid (KA) in the mouse hippocampus is strain dependent. Following KA administration, the large majority of hippocampal pyramidal cells die in the FVB/N (FVB) mouse, while the pyramidal cells of the C57BL/6 (B6) strain are largely spared. We generated aggregation chimeras between the sensitive FVB and the resistant B6 strains to investigate whether intrinsic or extrinsic features of a neuron confer cell vulnerability or resistance to KA. The constitutive expression of transgenic green fluorescence protein (GFP) or β-galactosidase expressed from the ROSA26 locus was used to mark cells in FVB or B6 mice, respectively. These makers enable the identification of cells from each parental genotype while TUNEL (terminal deoxynucleotidyl transferase-mediated biotinylated dUTP nick end labeling)-staining labeled dying cells. The analysis of the percentage of dying cells in FVB-GFP ↔ B6-ROSA chimeras yielded an intriguing mix of both intrinsic and extrinsic factors in the readout of cell phenotype. Thus, normally resistant B6-ROSA pyramidal neurons demonstrated an increasing sensitivity to KA, in a linear fashion, when the percentage of FVB-GFP cells was increased, either across chimeras or in different regions of the same chimera. However, the death of B6-ROSA pyramidal cells never exceeded ∼70% of the total amount of B6 neurons regardless of the amount of FVB cells in the chimeric hippocampus. In a similar manner, FVB-GFP cells show lower amounts of cell death in chimeras that are colonized by B6-ROSA cells, but again, are never fully rescued. These data indicate that both intrinsic and extrinsic factors modulate the sensitivity of hippocampal pyramidal cells to kainic acid.
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Lee MJ, Jang M, Jung HS, Kim SH, Cho IH. Ethyl pyruvate attenuates formalin-induced inflammatory nociception by inhibiting neuronal ERK phosphorylation. Mol Pain 2012; 8:40. [PMID: 22640699 PMCID: PMC3472237 DOI: 10.1186/1744-8069-8-40] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Accepted: 05/10/2012] [Indexed: 12/28/2022] Open
Abstract
Background Ethyl pyruvate (EP) possesses anti-inflammatory activity. However, the potential anti-nociceptive value of EP for the treatment of the inflammatory nociception is largely unknown. We investigated whether EP could have any anti-nociceptive effect on inflammatory pain, after systemic administration of EP (10, 50, and 100 mg/kg, i.p.), 1 hour before formalin (5%, 50 μl) injection into the plantar surface of the hind paws of rats. Results EP significantly decreased formalin-induced nociceptive behavior during phase II, the magnitude of paw edema, and the activation of c-Fos in L4-L5 spinal dorsal horn. EP also attenuated the phosphorylation of extracellular signal-regulated kinase (ERK) in the neurons of L4-L5 spinal dorsal horn after formalin injection. Interestingly, the i.t. administration of PD98059, an ERK upstream kinase (MEK) inhibitor, completely blocked the formalin-induced inflammatory nociceptive responses. Conclusions These results demonstrate that EP may effectively inhibit formalin-induced inflammatory nociception via the inhibition of neuronal ERK phosphorylation in the spinal dorsal horn, indicating its therapeutic potential in suppressing acute inflammatory pain.
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Affiliation(s)
- Min Jung Lee
- Department of Anatomy, College of Oriental Medicine, and Institute of Oriental Medicine, Kyung Hee University, Seoul, 130-701, Republic of Korea
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48
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Hong J, Kim BK, Lim H, Lee S, Lee SJ. Identification and characterization of triamcinolone acetonide, a microglial-activation inhibitor. Immunopharmacol Immunotoxicol 2012; 34:912-8. [PMID: 22551518 DOI: 10.3109/08923973.2012.671332] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Recent studies show that necrotic neuronal cells (NNC) activate microglia, thereby leading to neuronal cell death. This suggests that chemicals that inhibit microglia activation may be used as neuroprotective drugs. In this context, we screened a chemical library for inhibitors of microglia activation. Using a screening system based on a nitrite assay, we isolated two chemicals that inhibit nitric oxide (NO) release from activated microglia: triamcinolone acetonide (TA) and amcinonide. The half-maximal inhibitory concentrations (IC50) of TA and amcinonide for NO release inhibition were 1.78 nM and 3.38 nM, respectively. These chemicals also inhibited NNC-induced expression of the proinflammatory genes iNOS, TNF-α, and IL-1β in glial cells. A study based on a luciferase assay revealed that TA attenuated NNC-induced microglia activation by blocking the NF-κB signaling pathway. In addition, TA protected cortical neurons in coculture with microglia from LPS/IFN-γ-induced neuronal cell death. In conclusion, TA may inhibit microglia activation and may protect neuronal cells from death induced by microglial activation.
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Affiliation(s)
- Jinpyo Hong
- Department of Neuroscience, Dental Research Institute, and Brain Korea 21, School of Dentistry, Seoul National University, Seoul, Republic of Korea
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Minocycline markedly reduces acute visceral nociception via inhibiting neuronal ERK phosphorylation. Mol Pain 2012; 8:13. [PMID: 22364340 PMCID: PMC3342906 DOI: 10.1186/1744-8069-8-13] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2011] [Accepted: 02/24/2012] [Indexed: 12/13/2022] Open
Abstract
Background Minocycline prevents the development of neuropathic and inflammatory pain by inhibiting microglial activation and postsynaptic currents. But, how minocycline obviates acute visceral pain is unclear. The present study investigated whether minocycline had an any antinociceptive effect on acetic acid-induced acute abdominal pain after intraperitoneal (i.p.) administration of saline or minocycline 1 hour before acetic acid injection (1.0%, 250 μl, i.p.). Results Minocycline (4, 10, or 40 mg/kg) significantly decreased acetic acid-induced nociception (0-60 minutes post-injection) and the enhancement in the number of c-Fos positive cells in the T5-L2 spinal cord induced by acetic acid injection. Also, the expression of spinal phosphorylated extracellular signal-regulated kinase (p-ERK) induced by acetic acid was reduced by minocycline pre-administration. Interestingly, intrathecal introduction of PD98059, an ERK upstream kinase inhibitor, markedly blocked the acetic acid-stimulated pain responses. Conclusions These results demonstrate that minocycline effectively inhibits acetic acid-induced acute abdominal nociception via the inhibition of neuronal p-ERK expression in the spinal cord, and that minocycline may have therapeutic potential in suppressing acute abdominal pain.
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Blaylock RL, Maroon J. Immunoexcitotoxicity as a central mechanism in chronic traumatic encephalopathy-A unifying hypothesis. Surg Neurol Int 2011; 2:107. [PMID: 21886880 PMCID: PMC3157093 DOI: 10.4103/2152-7806.83391] [Citation(s) in RCA: 128] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Accepted: 06/06/2011] [Indexed: 12/17/2022] Open
Abstract
Some individuals suffering from mild traumatic brain injuries, especially repetitive mild concussions, are thought to develop a slowly progressive encephalopathy characterized by a number of the neuropathological elements shared with various neurodegenerative diseases. A central pathological mechanism explaining the development of progressive neurodegeneration in this subset of individuals has not been elucidated. Yet, a large number of studies indicate that a process called immunoexcitotoxicity may be playing a central role in many neurodegenerative diseases including chronic traumatic encephalopathy (CTE). The term immunoexcitotoxicity was first coined by the lead author to explain the evolving pathological and neurodevelopmental changes in autism and the Gulf War Syndrome, but it can be applied to a number of neurodegenerative disorders. The interaction between immune receptors within the central nervous system (CNS) and excitatory glutamate receptors trigger a series of events, such as extensive reactive oxygen species/reactive nitrogen species generation, accumulation of lipid peroxidation products, and prostaglandin activation, which then leads to dendritic retraction, synaptic injury, damage to microtubules, and mitochondrial suppression. In this paper, we discuss the mechanism of immunoexcitotoxicity and its link to each of the pathophysiological and neurochemical events previously described with CTE, with special emphasis on the observed accumulation of hyperphosphorylated tau.
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Affiliation(s)
- Russell L Blaylock
- Theoretical Neurosciences, LLC Visiting Professor of Biology, Belhaven University, Jackson, MS 315 Rolling Meadows Rd, Ridgeland, MS 39157, USA
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