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Yang Y, Liu T, Li J, Yan D, Hu Y, Wu P, Fang F, McQuillan PM, Hang W, Leng J, Hu Z. General anesthetic agents induce neurotoxicity through astrocytes. Neural Regen Res 2024; 19:1299-1307. [PMID: 37905879 DOI: 10.4103/1673-5374.385857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 09/09/2023] [Indexed: 11/02/2023] Open
Abstract
ABSTRACT Neuroscientists have recognized the importance of astrocytes in regulating neurological function and their influence on the release of glial transmitters. Few studies, however, have focused on the effects of general anesthetic agents on neuroglia or astrocytes. Astrocytes can also be an important target of general anesthetic agents as they exert not only sedative, analgesic, and amnesic effects but also mediate general anesthetic-induced neurotoxicity and postoperative cognitive dysfunction. Here, we analyzed recent advances in understanding the mechanism of general anesthetic agents on astrocytes, and found that exposure to general anesthetic agents will destroy the morphology and proliferation of astrocytes, in addition to acting on the receptors on their surface, which not only affect Ca2+ signaling, inhibit the release of brain-derived neurotrophic factor and lactate from astrocytes, but are even involved in the regulation of the pro- and anti-inflammatory processes of astrocytes. These would obviously affect the communication between astrocytes as well as between astrocytes and neighboring neurons, other neuroglia, and vascular cells. In this review, we summarize how general anesthetic agents act on neurons via astrocytes, and explore potential mechanisms of action of general anesthetic agents on the nervous system. We hope that this review will provide a new direction for mitigating the neurotoxicity of general anesthetic agents.
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Affiliation(s)
- Yanchang Yang
- Department of Anesthesiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
| | - Tiantian Liu
- Department of Anesthesiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
- Department of Anesthesiology, Ningbo Women and Children's Hospital, Ningbo, Zhejiang Province, China
| | - Jun Li
- Department of Anesthesiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
- Department of Anesthesiology, Shulan (Hangzhou) Hospital Affiliated to Zhejiang Shuren University Shulan International Medical College, Hangzhou, Zhejiang Province, China
| | - Dandan Yan
- Department of Anesthesiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
| | - Yuhan Hu
- Cell Biology Department, Yale University, New Haven, CT, USA
| | - Pin Wu
- Department of Anesthesiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
| | - Fuquan Fang
- Department of Anesthesiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
| | - Patrick M McQuillan
- Department of Anesthesiology, Penn State Hershey Medical Centre, Penn State College of Medicine, Hershey, PA, USA
| | - Wenxin Hang
- Department of Anesthesiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
| | - Jianhang Leng
- Department of Central Laboratory, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
| | - Zhiyong Hu
- Department of Anesthesiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
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Puthillathu N, Moffett JR, Korotcov A, Bosomtwi A, Vengilote R, Krishnan JKS, Johnson EA, Arun P, Namboodiri AM. Brief isoflurane administration as an adjunct treatment to control organophosphate-induced convulsions and neuropathology. Front Pharmacol 2023; 14:1293280. [PMID: 38230376 PMCID: PMC10790757 DOI: 10.3389/fphar.2023.1293280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 11/21/2023] [Indexed: 01/18/2024] Open
Abstract
Organophosphate-based chemical agents (OP), including nerve agents and certain pesticides such as paraoxon, are potent acetylcholinesterase inhibitors that cause severe convulsions and seizures, leading to permanent central nervous system (CNS) damage if not treated promptly. The current treatment regimen for OP poisoning is intramuscular injection of atropine sulfate with an oxime such as pralidoxime (2-PAM) to mitigate cholinergic over-activation of the somatic musculature and autonomic nervous system. This treatment does not provide protection against CNS cholinergic overactivation and therefore convulsions require additional medication. Benzodiazepines are the currently accepted treatment for OP-induced convulsions, but the convulsions become refractory to these GABAA agonists and repeated dosing has diminishing effectiveness. As such, adjunct anticonvulsant treatments are needed to provide improved protection against recurrent and prolonged convulsions and the associated excitotoxic CNS damage that results from them. Previously we have shown that brief, 4-min administration of 3%-5% isoflurane in 100% oxygen has profound anticonvulsant and CNS protective effects when administered 30 min after a lethal dose of paraoxon. In this report we provide an extended time course of the effectiveness of 5% isoflurane delivered for 5 min, ranging from 60 to 180 min after a lethal dose of paraoxon in rats. We observed substantial effectiveness in preventing neuronal loss as shown by Fluoro-Jade B staining when isoflurane was administered 1 h after paraoxon, with diminishing effectiveness at 90, 120 and 180 min. In vivo magnetic resonance imaging (MRI) derived T2 and mean diffusivity (MD) values showed that 5-min isoflurane administration at a concentration of 5% prevents brain edema and tissue damage when administered 1 h after a lethal dose of paraoxon. We also observed reduced astrogliosis as shown by GFAP immunohistochemistry. Studies with continuous EEG monitoring are ongoing to demonstrate effectiveness in animal models of soman poisoning.
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Affiliation(s)
- Narayanan Puthillathu
- Department of Anatomy, Physiology, and Genetics, Neuroscience Program and Molecular and Cell Biology Program, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - John R. Moffett
- Department of Anatomy, Physiology, and Genetics, Neuroscience Program and Molecular and Cell Biology Program, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Alexandru Korotcov
- Department of Radiology and Radiological Sciences, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
- The Henry M. Jackson Foundation for the Advancement of Military Medicine (HJF), Bethesda, MD, United States
| | - Asamoah Bosomtwi
- The Henry M. Jackson Foundation for the Advancement of Military Medicine (HJF), Bethesda, MD, United States
| | - Ranjini Vengilote
- Department of Anatomy, Physiology, and Genetics, Neuroscience Program and Molecular and Cell Biology Program, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Jishnu K. S. Krishnan
- Department of Anatomy, Physiology, and Genetics, Neuroscience Program and Molecular and Cell Biology Program, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Erik A. Johnson
- Department of Neuroscience, United States Army Medical Research Institute of Chemical Defense, Gunpowder, MD, United States
| | - Peethambaran Arun
- Department of Anatomy, Physiology, and Genetics, Neuroscience Program and Molecular and Cell Biology Program, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Aryan M. Namboodiri
- Department of Anatomy, Physiology, and Genetics, Neuroscience Program and Molecular and Cell Biology Program, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
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Zhang C, Xing Z, Tan M, Wu Y, Zeng W. Roflumilast Ameliorates Isoflurane-Induced Inflammation in Astrocytes via the CREB/BDNF Signaling Pathway. ACS OMEGA 2021; 6:4167-4174. [PMID: 33644540 PMCID: PMC7906587 DOI: 10.1021/acsomega.0c04799] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 12/29/2020] [Indexed: 06/12/2023]
Abstract
Background and purpose: Astrocyte-mediated neuroinflammation plays an important role in anesthetic isoflurane-induced cognitive impairment. Roflumilast, a selective inhibitor of phosphodiesterase-4 (PDE-4) used for the treatment of chronic obstructive pulmonary disease (COPD), has displayed a wide range of anti-inflammatory capacity in different types of cells and tissues. In the current study, we aimed to investigate whether roflumilast possesses a protective effect against isoflurane-induced insults in mouse primary astrocytes. Methods: Primary astrocytes were isolated from the cerebral cortices of immature rats. The production of NO was determined using DAF-FM DA staining assay. QRT-PCR and western blot were used to evaluate the expression levels of iNOS, COX-2, and BDNF in the astrocytes treated with different therapies. The gene expressions and concentrations of IL-6 and MCP-1 released by the astrocytes were detected using qRT-PCR and ELISA, respectively. The expression levels of phosphorylated CREB and PGE2 were determined using western blot and ELISA, respectively. H89 was introduced to evaluate the function of CREB. Recombinant human BDNF and ANA-12 were used to verify the role of BDNF. Results: The upregulated iNOS, excessive production of NO, IL-6, and MCP-1, and activated COX-2/PGE2 signaling pathways in the astrocytes induced by isoflurane were significantly reversed by the introduction of roflumilast, in a dose-dependent manner. Subsequently, we found that BDNF could be upregulated by roflumilast, which was verified to be related to the activation of CREB and blocked by H89 (a CREB inhibitor). In addition, the COX-2/PGE2 signaling pathway activated by isoflurane can be inactivated by recombinant human BDNF. Finally, the regulatory effect of roflumilast against the isoflurane-activated COX-2/PGE2 signaling pathway was significantly blocked by ANA-12, which is a BDNF inhibitor. Conclusion: Roflumilast might ameliorate isoflurane-induced inflammation in astrocytes via the CREB/BDNF signaling pathway.
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Rodent models for intravascular ischemic cerebral infarction: a review of influencing factors and method optimization. Neuroreport 2020; 31:1154-1160. [PMID: 32991526 DOI: 10.1097/wnr.0000000000001529] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Rodent models for cerebral infarction are useful for studying human focal ischemic cerebral infarction, by simulating etiological and pathophysiological mechanisms. However, differences in the selection of anesthetic drugs, surgical methods and other factors may affect the extent to which preclinical models reflect the human condition. This review summarizes these factors. We searched pertinent literature from the MEDLINE and Web of Science databases, and reviewed differences in rodent strain, anesthesia method, sex, surgical method, timing of surgery, and factors influencing postoperative evaluation. In particular, circadian rhythm was found to have a significant impact on the outcome of cerebral infarction in rodent models. This information will enable researchers to quickly and clearly select appropriate modeling methods, acquire reliable quantitative experimental results, and obtain basic data for fundamental mechanism research.
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Zhang Y, Wu R, Gu C, Gao F, Hu X, Zang P, Dong T. A study on role and mechanism of TLR4/NF-κB pathway in cognitive impairment induced by cerebral small vascular disease. Clin Hemorheol Microcirc 2019; 72:201-210. [PMID: 30689560 DOI: 10.3233/ch-180515] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVE To investigate the role and potential mechanism of Toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-κB) signaling pathway in cognitive impairment induced by cerebral small vascular disease (CSVD), so as to provide a reference for the clinical treatment of CSVD-induced cognitive impairment. METHODS Mice with TLR4 gene knockout (n = 20) and those with wild-type TLR4 gene (n = 40) aged 8-10 weeks old were divided into blank control group (Control group, n = 20), wild-type + CSVD group (WT + CSVD group, n = 20) and TLR4 gene knockout + CSVD group (TLR4 KO + CSVD group, n = 20). Allogeneic thrombosis (particle diameter: 50-70 mm) was injected to the mouse's external carotid artery to create a model of learning and memory dysfunction. Step-down test and Y-type maze test were utilized to examine the learning and memory abilities of the mice. Reverse transcription-polymerase chain reaction (RT-PCR) and immunoblotting techniques were adopted to measure the levels of apoptosis-related genes [B-cell lymphoma/leukemia-2 (Bcl-2), Bcl-2-associated X protein (Bax), C-caspase-3 and T-caspase-3] in the brain tissues of mice. Terminal dexynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) method was applied to detect the apoptosis of neuronal cells in the brain tissues. Meanwhile, the levels of oxidative stress markers, including superoxide dismutase (SOD), gp91 and malondialdehyde (MDA), were measured. Finally, the expression level of TLR4/NF-κB pathway was detected. RESULTS The latency in the step-down test in the WT + CSVD group was remarkably longer than that in the Control group, and the number of errors was evidently larger than that in the Control group (p < 0.05). At the same time, in the WT + CSVD group, the expression levels of pro-apoptotic genes Bax and C-caspase-3 were up-regulated markedly, while the expression level of anti-apoptotic gene Bcl-2 declined notably (p < 0.05). TUNEL results showed that the number of apoptotic cells in the brain tissues in the WT + CSVD group was about 12 times that in the Control group (p < 0.05). Meanwhile, the SOD expression level was lowered, and the MDA expression level was elevated in the brain tissues in the WT + CSVD group. In addition, the TLR4/NF-κB pathway was prominently activated in the mice in the WT + CSVD group (p < 0.05). After TLR4 gene knockout, the cognitive functions of the mice were improved markedly, and the apoptosis of neuronal cells and oxidative stress in the brain tissues were suppressed significantly in the meantime. Moreover, the activation of the TLR4/NF-κB signaling pathway was also inhibited. CONCLUSION The TLR4/NF-κB pathway is involved in the occurrence and development of CSVD-induced cognitive impairment through regulating oxidative stress and cell apoptosis.
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Affiliation(s)
- Yi Zhang
- Department of Neurology, Gansu Provincial Hospital, Lanzhou, Gansu, China
| | - Ruipeng Wu
- Department of Neurology, Gansu Provincial Hospital, Lanzhou, Gansu, China
| | - Cheng Gu
- Department of Neurology, Gansu Provincial Hospital, Lanzhou, Gansu, China
| | - Fulin Gao
- Department of Neurology, Gansu Provincial Hospital, Lanzhou, Gansu, China
| | - Xiaojuan Hu
- Department of Neurology, Gansu Provincial Hospital, Lanzhou, Gansu, China
| | - Peixi Zang
- Department of Neurology, Gansu Provincial Hospital, Lanzhou, Gansu, China
| | - Tong Dong
- Department of Neurology, Gansu Provincial Hospital, Lanzhou, Gansu, China
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Lu W, Xv L, Wen J. Protective effect of extract of the Camellia japonica L. on cerebral ischemia-reperfusion injury in rats. ARQUIVOS DE NEURO-PSIQUIATRIA 2019; 77:39-46. [DOI: 10.1590/0004-282x20180146] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2018] [Accepted: 09/28/2018] [Indexed: 01/08/2023]
Abstract
ABSTRACT Objective: We investigated the protective effect of the extract of the Camellia japonica L. flower on cerebral ischemia-reperfusion injury in rats. Methods: The rat ischemia-reperfusion injury was induced by middle cerebral artery occlusion for 90 minutes and reperfusion for 48 hours. The animals received an intravenous injection once a day of 20, 40, 80 mg/kg extract of C. japonica for three consecutive days before the ischemia reperfusion. The learning and memory function, the infarct volume, serum malondialdehyde (MDA) level and lactate dehydrogenase activity, and extravasation of immunoglobulin G (IgG) into cerebral parenchyma were assessed as the cell damage index. Results: Pretreatment with extract of C. japonica markedly reduced the infarct volume, serum malondialdehyde level and lactate dehydrogenase activity, and markedly inhibited the extravasation of IgG. Moreover, pretreatment with extract of C. japonica may also inhibit the learning and memory deficits induced by an ischemia-reperfusion injury. Conclusion: It was concluded that pretreatment with extract of C. japonica has a protective effect on cerebral ischemia-reperfusion injury in rats.
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Affiliation(s)
| | - Ling Xv
- Hefei Technology College, China
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Hillman TC, Matei N, Tang J, Zhang JH. Developing a standardized system of exposure and intervention endpoints for isoflurane in preclinical stroke models. Med Gas Res 2019; 9:46-51. [PMID: 30950418 PMCID: PMC6463442 DOI: 10.4103/2045-9912.254640] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 03/12/2019] [Indexed: 11/04/2022] Open
Abstract
Isoflurane is a regularly used anesthetic in translational research. Isoflurane facilitates invasive surgery and a rapid recovery. Specifically, in the pathology of stroke, controversy has surrounded isoflurane's intrinsic neuroprotective abilities, affecting apoptosis, excitotoxicity, and blood brain barrier disruption. Due to the intrinsic neuroprotective nature and lack of standardized guidelines for the use of isoflurane, research has shifted away from this gas in most animal models. Antagonistically, studies have also reported that no neuroprotective effects are observed when a surgery is accompanied with isoflurane exposure under 20 minutes. Isoflurane affects the pathophysiology in stroke patients by altering critical pathways in endothelial, neuronal, and microglial cells. Current studies have elucidated isoflurane neuroprotection to be time dependent and may be minimized in experimental designs if the exposure time is limited to a specific window. Therefore, with detailed and extensive literature on anesthetics, we can hypothesize that isoflurane exposure under the 20-minute benchmark, behavior and molecular pathways can be evaluated at any time-point following ischemic insult without confounding artifacts from isoflurane; however, If the exposure to isoflurane exceeds 20 minutes, the acute neuroprotective effects are evident for 2 weeks in the model, which should be accounted for in molecular and behavioral assessments, with either isoflurane inhibitors or a control group at 2 weeks post middle cerebral artery occlusion. The purpose of this review is to suggest a detailed and standardized outline for interventions and behavioral assessments after the use of isoflurane in experimental designs.
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Affiliation(s)
- Tyler C. Hillman
- Department of Physiology and Pharmacology, Loma Linda University, Loma Linda, CA, USA
| | - Nathanael Matei
- Department of Physiology and Pharmacology, Loma Linda University, Loma Linda, CA, USA
| | - Jiping Tang
- Department of Physiology and Pharmacology, Loma Linda University, Loma Linda, CA, USA
| | - John H. Zhang
- Department of Physiology and Pharmacology, Loma Linda University, Loma Linda, CA, USA
- Department of Anesthesiology, Loma Linda University, Loma Linda, CA, USA
- Department of Neurosurgery, Loma Linda University, Loma Linda, CA, USA
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Li XL, Wang YL, Zheng J, Zhang Y, Zhang XF. Inhibiting expression of HSP60 and TLR4 attenuates paraquat-induced microglial inflammation. Chem Biol Interact 2018; 299:179-185. [PMID: 30584891 DOI: 10.1016/j.cbi.2018.12.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 11/26/2018] [Accepted: 12/21/2018] [Indexed: 11/26/2022]
Abstract
Accumulating evidences suggest that heat shock protein 60 (HSP60) and toll-like receptor 4 (TLR4) are involved in triggering inflammatory response in microglia. Paraquat (PQ) evokes microglial inflammation by up-regulating expression of HSP60-TLR4-myeloid differentiation factor 88 (Myd88)-nuclear factor-kappa B (NF-κB) in vitro. The aim of this study is to investigate the potential modulatory roles of HSP60 and TLR4 in PQ-induced inflammation. Before treated with PQ, microglia BV2 cells were pretreated using siRNA to knockdown HSP60 or with specific inhibitor to inhibit TLR4 expression. Expression of TLR4 and MyD88, and nuclear translocation of NF-κB subunit p65 were studied with immunoblotting and immunofluorescence, respectively. Expression of pro-inflammatory factors was assessed with quantitative real-time PCR. Knockdown of HSP60 or inhibition of TLR4 significantly reduced the expression of TLR4 and MyD88 and decreased the accumulation of NF-κB p65 in the nucleus. Gene expression of tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), interleukin-6 (IL-6) and inducible nitric oxide synthase (iNOS) were also significantly decreased in response to PQ. These results suggest that HSP60 and TLR4 can modulate intracellular signaling of PQ-induced inflammation. Inhibiting HSP60 or TLR4 reduces significantly the intensity of inflammation in PQ-activated microglia.
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Affiliation(s)
- Xin-Lei Li
- Department of Human Anatomy, School of Basic Medical Sciences, Harbin Medical University, Harbin, Heilongjiang Province, 150081, PR China
| | - Yong-Ling Wang
- Department of Toxicology, Public Health School, Harbin Medical University, Harbin, Heilongjiang Province, 150081, PR China
| | - Jing Zheng
- Department of Public Health Monitoring, Heilongjiang Center for Disease Control and Prevention, Harbin, Heilongjiang Province, 150030, PR China
| | - Yang Zhang
- Department of Toxicology, Public Health School, Harbin Medical University, Harbin, Heilongjiang Province, 150081, PR China.
| | - Xiao-Feng Zhang
- Department of Toxicology, Public Health School, Harbin Medical University, Harbin, Heilongjiang Province, 150081, PR China.
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Li M, Liu J, Bi Y, Chen J, Zhao L. Potential Medications or Compounds Acting on Toll-like Receptors in Cerebral Ischemia. Curr Neuropharmacol 2018; 16:160-175. [PMID: 28571545 PMCID: PMC5883378 DOI: 10.2174/1570159x15666170601125139] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 05/24/2017] [Accepted: 05/31/2017] [Indexed: 01/22/2023] Open
Abstract
Background: Toll-like receptors play an integral role in the process of inflammatory response after ischemic in-jury. The therapeutic potential acting on TLRs is worth of evaluations. The aim of this review was to introduce readers some potential medications or compounds which could alleviate the ischemic damage via TLRs. Methods: Research articles online on TLRs were reviewed. Categorizations were listed according to the follows, methods acting on TLRs directly, modulations of MyD88 or TRIF signaling pathway, and the ischemic tolerance induced by the pre-conditioning or postconditioning with TLR ligands or minor cerebral ischemia via acting on TLRs. Results: There are only a few studies concerning on direct effects. Anti-TLR4 or anti-TLR2 therapies may serve as promis-ing strategies in acute events. Approaches targeting on inhibiting NF-κB signaling pathway and enhancing interferon regu-latory factor dependent signaling have attracted great interests. Not only drugs but compounds extracted from traditional Chinese medicine have been used to identify their neuroprotective effects against cerebral ischemia. In addition, many re-searchers have reported the positive therapeutic effects of preconditioning with agonists of TLR2, 3, 4, 7 and 9. Several trails have also explored the potential of postconditioning, which provide a new idea in ischemic treatments. Considering all the evidence above, many drugs and new compounds may have great potential to reduce ischemic insults. Conclusion: This review will focus on promising therapies which exerting neuroprotective effects against ischemic injury by acting on TLRs.
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Affiliation(s)
- Man Li
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Jing Liu
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.,Department of Neurology, Puai Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430033, China
| | - Ying Bi
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Jixiang Chen
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Lei Zhao
- Department of Infectious Diseases, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Pi Z, Lin H, Yang J. Isoflurane reduces pain and inhibits apoptosis of myocardial cells through the phosphoinositide 3-kinase/protein kinase B signaling pathway in mice during cardiac surgery. Mol Med Rep 2018; 17:6497-6505. [PMID: 29488606 PMCID: PMC5928630 DOI: 10.3892/mmr.2018.8642] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 11/28/2017] [Indexed: 01/27/2023] Open
Abstract
Heart bypass surgery is the most common treatment for myocardial ischemia. Clinical investigations have revealed that isoflurane anesthesia is efficient to alleviate pain during cardiac surgery, including heart bypass surgery. Previous studies have revealed the protective effects of isoflurane on myocardial cells of patients with myocardial ischemia during the perioperative period. The present study aimed to investigate the mechanism underlying the protective effects of isoflurane on myocardial cells in mice with myocardial ischemia. ELISA, flow cytometry, immunofluorescence and western blotting were used to analyze the effects of isoflurane anesthesia on myocardial cells. Briefly, myocardial cell apoptosis and viability, pain, phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) signaling pathway expression and the pharmacodynamics of isoflurane were studied in mice treated with isoflurane for heart bypass surgery. The results demonstrated that isoflurane anesthesia efficiently attenuated pain in mice during surgery. Viability and apoptosis of myocardial cells was also improved by isoflurane in vitro and in vivo. The PI3K/AKT pathway was upregulated in myocardial cells on day 3 post-operation. Mechanistically, isoflurane promoted PI3K/AKT activation, upregulated B-cell lymphoma 2 (Bcl-2)-associated X protein and Bcl-2 expression levels, and reduced the expression levels of caspase-3 and caspase-8 in myocardial cells. In conclusion, the findings indicated that isoflurane is beneficial for pain attenuation and inhibits apoptosis of myocardial cells via the PI3K/AKT signaling pathway in mice during cardiac surgery.
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Affiliation(s)
- Zhibing Pi
- Department of Anesthesiology of The First Affiliated Hospital of Wenzhou University, Wenzhou, Zhejiang 325000, P.R. China
| | - Hai Lin
- Department of Anesthesiology of The First Affiliated Hospital of Wenzhou University, Wenzhou, Zhejiang 325000, P.R. China
| | - Jianping Yang
- Department of Anesthesiology of The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215006, P.R. China
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Chen S, Lotz C, Roewer N, Broscheit JA. Comparison of volatile anesthetic-induced preconditioning in cardiac and cerebral system: molecular mechanisms and clinical aspects. Eur J Med Res 2018; 23:10. [PMID: 29458412 PMCID: PMC5819224 DOI: 10.1186/s40001-018-0308-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Accepted: 02/12/2018] [Indexed: 12/17/2022] Open
Abstract
Volatile anesthetic-induced preconditioning (APC) has shown to have cardiac and cerebral protective properties in both pre-clinical models and clinical trials. Interestingly, accumulating evidences demonstrate that, except from some specific characters, the underlying molecular mechanisms of APC-induced protective effects in myocytes and neurons are very similar; they share several major intracellular signaling pathways, including mediating mitochondrial function, release of inflammatory cytokines and cell apoptosis. Among all the experimental results, cortical spreading depolarization is a relative newly discovered cellular mechanism of APC, which, however, just exists in central nervous system. Applying volatile anesthetic preconditioning to clinical practice seems to be a promising cardio-and neuroprotective strategy. In this review, we also summarized and discussed the results of recent clinical research of APC. Despite all the positive experimental evidences, large-scale, long-term, more precisely controlled clinical trials focusing on the perioperative use of volatile anesthetics for organ protection are still needed.
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Affiliation(s)
- Shasha Chen
- Department of Anesthesiology and Critical Care, University of Wuerzburg, Oberduerrbacher Str.6, 97080, Wuerzburg, Germany.
| | - Christopher Lotz
- Department of Anesthesiology and Critical Care, University of Wuerzburg, Oberduerrbacher Str.6, 97080, Wuerzburg, Germany
| | - Norbert Roewer
- Department of Anesthesiology and Critical Care, University of Wuerzburg, Oberduerrbacher Str.6, 97080, Wuerzburg, Germany
| | - Jens-Albert Broscheit
- Department of Anesthesiology and Critical Care, University of Wuerzburg, Oberduerrbacher Str.6, 97080, Wuerzburg, Germany
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Integrity of Cerebellar Fastigial Nucleus Intrinsic Neurons Is Critical for the Global Ischemic Preconditioning. Brain Sci 2017; 7:brainsci7100121. [PMID: 28934119 PMCID: PMC5664048 DOI: 10.3390/brainsci7100121] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 09/15/2017] [Accepted: 09/18/2017] [Indexed: 01/25/2023] Open
Abstract
Excitation of intrinsic neurons of cerebellar fastigial nucleus (FN) renders brain tolerant to local and global ischemia. This effect reaches a maximum 72 h after the stimulation and lasts over 10 days. Comparable neuroprotection is observed following sublethal global brain ischemia, a phenomenon known as preconditioning. We hypothesized that FN may participate in the mechanisms of ischemic preconditioning as a part of the intrinsic neuroprotective mechanism. To explore potential significance of FN neurons in brain ischemic tolerance we lesioned intrinsic FN neurons with excitotoxin ibotenic acid five days before exposure to 20 min four-vessel occlusion (4-VO) global ischemia while analyzing neuronal damage in Cornu Ammoni area 1 (CA1) hippocampal area one week later. In FN-lesioned animals, loss of CA1 cells was higher by 22% compared to control (phosphate buffered saline (PBS)-injected) animals. Moreover, lesion of FN neurons increased morbidity following global ischemia by 50%. Ablation of FN neurons also reversed salvaging effects of five-minute ischemic preconditioning on CA1 neurons and morbidity, while ablation of cerebellar dentate nucleus neurons did not change effect of ischemic preconditioning. We conclude that FN is an important part of intrinsic neuroprotective system, which participates in ischemic preconditioning and may participate in naturally occurring neuroprotection, such as "diving response".
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Park CW, Lee TK, Cho JH, Kim IH, Lee JC, Shin BN, Ahn JH, Kim SK, Shin MC, Ohk TG, Cho JH, Won MH, Lee YJ, Seo JY, Park JH. Rufinamide pretreatment attenuates ischemia-reperfusion injury in the gerbil hippocampus. Neurol Res 2017; 39:941-952. [PMID: 28782435 DOI: 10.1080/01616412.2017.1362189] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
OBJECTIVES Rufinamide, a voltage-gated sodium channel (VGSC) blocker, is widely used for the clinical treatment of seizures associated with Lennox-Gastaut syndrome. Previous studies have demonstrated that VGSC blockers have neuroprotective properties against ischemic damage following experimental cerebral ischemia. However, protective effects of rufinamide against cerebral ischemic insults have not been addressed. Therefore, in the present study, we firstly examined neuroprotective effects of rufinamide using a gerbil model of transient global cerebral ischemia. METHODS Gerbils were established by the occlusion of common carotid arteries for 5 min. The gerbils were divided into vehicle-treated sham-operated group, vehicle-treated ischemia-operated group, 50 and 100 mg/kg rufinamide-treated sham-operated groups, and 50 and 100 mg/kg rufinamide-treated ischemia-operated groups. Rufinamide was administrated intraperitoneally once daily for 3 days before ischemic surgery. To examine neuroprotective effects of rufinamide, we carried out cresyl violet staining, neuronal nuclear antigen immunohistochemistry and Fluoro-Jade B histofluorescence staining. In addition, we examined gliosis using immunohistochemistry for glial fibrillary acidic protein (a marker for astrocytes) and ionized calcium-binding adapter molecule 1 (a marker for microglia). RESULTS We found that pre-treatment with 100 mg/kg of rufinamide effectively protected pyramidal neurons in the hippocampal cornus ammonis 1 (CA1) area after transient global cerebral ischemia. In addition, pre-treatment with 100 mg/kg of rufinamide significantly attenuated activations of astrocytes and microglia in the ischemic CA1 area. DISCUSSION These findings suggest that rufinamide can display neuroprotective effect against cerebral ischemic insults and that its neuroprotective effect may involve the attenuation of ischemia-induced glial activation.
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Affiliation(s)
- Chan Woo Park
- a Department of Emergency Medicine, School of Medicine , Kangwon National University , Chuncheon , South Korea
| | - Tae-Kyeong Lee
- b Department of Neurobiology, School of Medicine , Kangwon National University , Chuncheon , South Korea
| | - Jeong Hwi Cho
- b Department of Neurobiology, School of Medicine , Kangwon National University , Chuncheon , South Korea
| | - In Hye Kim
- b Department of Neurobiology, School of Medicine , Kangwon National University , Chuncheon , South Korea
| | - Jae-Chul Lee
- b Department of Neurobiology, School of Medicine , Kangwon National University , Chuncheon , South Korea
| | - Bich-Na Shin
- c Department of Physiology, College of Medicine , Hallym University , Chuncheon , South Korea
| | - Ji Hyeon Ahn
- d Department of Biomedical Science and Research Institute for Bioscience and Biotechnology , Hallym University , Chuncheon , South Korea
| | - Sung Koo Kim
- e Department of Pediatrics , Dongtan Sacred Heart Hospital, School of Medicine, Hallym University , Hwaseong , South Korea
| | - Myoung Cheol Shin
- a Department of Emergency Medicine, School of Medicine , Kangwon National University , Chuncheon , South Korea
| | - Taek Geun Ohk
- a Department of Emergency Medicine, School of Medicine , Kangwon National University , Chuncheon , South Korea
| | - Jun Hwi Cho
- a Department of Emergency Medicine, School of Medicine , Kangwon National University , Chuncheon , South Korea
| | - Moo-Ho Won
- b Department of Neurobiology, School of Medicine , Kangwon National University , Chuncheon , South Korea
| | - Young Joo Lee
- f Department of Emergency Medicine , Seoul Hospital, College of Medicine, Sooncheonhyang University , Seoul , South Kore
| | - Jeong Yeol Seo
- g Department of Emergency Medicine , Chuncheon Sacred Heart Hospital, College of Medicine, Hallym University , Chuncheon , South Korea
| | - Joon Ha Park
- d Department of Biomedical Science and Research Institute for Bioscience and Biotechnology , Hallym University , Chuncheon , South Korea
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Morrison JC, Cepurna WO, Tehrani S, Choe TE, Jayaram H, Lozano DC, Fortune B, Johnson EC. A Period of Controlled Elevation of IOP (CEI) Produces the Specific Gene Expression Responses and Focal Injury Pattern of Experimental Rat Glaucoma. Invest Ophthalmol Vis Sci 2017; 57:6700-6711. [PMID: 27942722 PMCID: PMC5156512 DOI: 10.1167/iovs.16-20573] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose We determine if several hours of controlled elevation of IOP (CEI) will produce the optic nerve head (ONH) gene expression changes and optic nerve (ON) damage pattern associated with early experimental glaucoma in rats. Methods The anterior chambers of anesthetized rats were cannulated and connected to a reservoir to elevate IOP. Physiologic parameters were monitored. Following CEI at various recovery times, ON cross-sections were graded for axonal injury. Anterior ONHs were collected at 0 hours to 10 days following CEI and RNA extracted for quantitative PCR measurement of selected messages. The functional impact of CEI was assessed by electroretinography (ERG). Results During CEI, mean arterial pressure (99 ± 6 mm Hg) and other physiologic parameters remained stable. An 8-hour CEI at 60 mm Hg produced significant focal axonal degeneration 10 days after exposure, with superior lesions in 83% of ON. Message analysis in CEI ONH demonstrated expression responses previously identified in minimally injured ONH following chronic IOP elevation, as well as their sequential patterns. Anesthesia with cannulation at 20 mm Hg did not alter these message levels. Electroretinographic A- and B-waves, following a significant reduction at 2 days after CEI, were fully recovered at 2 weeks, while peak scotopic threshold response (pSTR) remained mildly but significantly depressed. Conclusions A single CEI reproduces ONH message changes and patterns of ON injury previously observed with chronic IOP elevation. Controlled elevation of IOP can allow detailed determination of ONH cellular and functional responses to an injurious IOP insult and provide a platform for developing future therapeutic interventions.
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Affiliation(s)
- John C Morrison
- The Kenneth C. Swan Ocular Neurobiology Laboratory, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, United States
| | - William O Cepurna
- The Kenneth C. Swan Ocular Neurobiology Laboratory, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, United States
| | - Shandiz Tehrani
- The Kenneth C. Swan Ocular Neurobiology Laboratory, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, United States
| | - Tiffany E Choe
- The Kenneth C. Swan Ocular Neurobiology Laboratory, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, United States
| | - Hari Jayaram
- The Kenneth C. Swan Ocular Neurobiology Laboratory, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, United States 2Glaucoma Service, NIHR Moorfields Biomedical Research Centre, London, United Kingdom
| | - Diana C Lozano
- The Kenneth C. Swan Ocular Neurobiology Laboratory, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, United States
| | - Brad Fortune
- Devers Eye Institute, Portland, Oregon, United States
| | - Elaine C Johnson
- The Kenneth C. Swan Ocular Neurobiology Laboratory, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, United States
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15
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Cheon SY, Kim SY, Kam EH, Lee JH, Kim JM, Kim EJ, Kim TW, Koo BN. Isoflurane preconditioning inhibits the effects of tissue-type plasminogen activator on brain endothelial cell in an in vitro model of ischemic stroke. Int J Med Sci 2017; 14:425-433. [PMID: 28539818 PMCID: PMC5441034 DOI: 10.7150/ijms.18037] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Accepted: 01/30/2017] [Indexed: 01/08/2023] Open
Abstract
Tissue-type plasminogen activator (tPA) is the only treatment for ischemic stroke. However, tPA could induce the intracranial hemorrhage (ICH), which is the main cause of death in ischemic stroke patient after tPA treatment. At present, there is no treatment strategy to ameliorate tPA-induced brain injury after ischemia. Therefore, we investigated the effect of pre-treated isoflurane, which is a volatile anesthetic and has beneficial effects on neurological dysfunction, brain edema and infarct volume in ischemic stroke model. In this study, we used oxygen/glucose deprivation and reperfusion (OGD/R) condition to mimic an ischemic stroke in vitro. Matrix metalloproteinases (MMP) activity was measured in endothelial cell media. Also, neuronal cell culture was performed to investigate the effect of pretreated isoflurane on the neuronal cell survival after tPA-induced injury during OGD/R. Isoflurane pretreatment prevented tPA-induced MMP-2 and MMP-9 activity and suppressed tPA-triggered LRP/NF-κB/Cox-2 signaling after OGD/R. Neuronal cells, incubated with endothelial cell conditioned medium (EC-CM) after tPA + OGD/R, showed upregulation of pro-apoptotic molecules. However, neurons incubated with isoflurane-pretreated EC-CM showed increased anti-apoptotic molecules. Our findings suggest that isoflurane pretreatment could attenuate tPA-exaggerated brain ischemic injury, by reducing tPA-induced LRP/NF-κB/Cox-2 in endothelial cells, endothelial MMP-2 and MMP-9 activation, and subsequent pro-apoptotic molecule in neurons after OGD/R.
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Affiliation(s)
- So Yeong Cheon
- Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.,Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - So Yeon Kim
- Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.,Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Eun Hee Kam
- Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.,Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Jae Hoon Lee
- Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.,Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Jeong Min Kim
- Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.,Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Eun Jung Kim
- Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.,Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Tae Whan Kim
- Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Bon-Nyeo Koo
- Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.,Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea
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Tanda G, Mereu M, Hiranita T, Quarterman JC, Coggiano M, Katz JL. Lack of Specific Involvement of (+)-Naloxone and (+)-Naltrexone on the Reinforcing and Neurochemical Effects of Cocaine and Opioids. Neuropsychopharmacology 2016; 41:2772-81. [PMID: 27296151 PMCID: PMC5026747 DOI: 10.1038/npp.2016.91] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 05/27/2016] [Accepted: 05/30/2016] [Indexed: 01/14/2023]
Abstract
Effective medications for drug abuse remain a largely unmet goal in biomedical science. Recently, the (+)-enantiomers of naloxone and naltrexone, TLR4 antagonists, have been reported to attenuate preclinical indicators of both opioid and stimulant abuse. To further examine the potential of these compounds as drug-abuse treatments, we extended the previous assessments to include a wider range of doses and procedures. We report the assessment of (+)-naloxone and (+)-naltrexone on the acute dopaminergic effects of cocaine and heroin determined by in vivo microdialysis, on the reinforcing effects of cocaine and the opioid agonist, remifentanil, tested under intravenous self-administration procedures, as well as the subjective effects of cocaine determined by discriminative-stimulus effects in rats. Pretreatments with (+)-naloxone or (+)-naltrexone did not attenuate, and under certain conditions enhanced the stimulation of dopamine levels produced by cocaine or heroin in the nucleus accumbens shell. Furthermore, although an attenuation of either cocaine or remifentanil self-administration was obtained at the highest doses of (+)-naloxone and (+)-naltrexone, those doses also attenuated rates of food-maintained behaviors, indicating a lack of selectivity of TLR4 antagonist effects for behaviors reinforced with drug injections. Drug-discrimination studies failed to demonstrate a significant interaction of (+)-naloxone with subjective effects of cocaine. The present studies demonstrate that under a wide range of doses and experimental conditions, the TLR4 antagonists, (+)-naloxone and (+)-naltrexone, did not specifically block neurochemical or behavioral abuse-related effects of cocaine or opioid agonists.
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Affiliation(s)
- Gianluigi Tanda
- Medication Development Program, Molecular Targets and Medication Discovery Branch, NIDA-IRP, NIH/DHHS, Baltimore, MD, USA,Medication Development Program, TRIAD Building, NIDA Suite 3301, 333 Cassell Drive, Baltimore, MD 21224, USA, Tel: +1-443-740-2580, Fax: +1-443-740-2111, E-mail:
| | - Maddalena Mereu
- Medication Development Program, Molecular Targets and Medication Discovery Branch, NIDA-IRP, NIH/DHHS, Baltimore, MD, USA
| | - Takato Hiranita
- Psychobiology Section, Molecular Neuropsychiatry Research Branch, NIDA-IRP, NIH/DHHS, Baltimore, MD, USA
| | - Juliana C Quarterman
- Medication Development Program, Molecular Targets and Medication Discovery Branch, NIDA-IRP, NIH/DHHS, Baltimore, MD, USA
| | - Mark Coggiano
- Medication Development Program, Molecular Targets and Medication Discovery Branch, NIDA-IRP, NIH/DHHS, Baltimore, MD, USA
| | - Jonathan L Katz
- Psychobiology Section, Molecular Neuropsychiatry Research Branch, NIDA-IRP, NIH/DHHS, Baltimore, MD, USA
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17
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Sun M, Deng B, Zhao X, Gao C, Yang L, Zhao H, Yu D, Zhang F, Xu L, Chen L, Sun X. Isoflurane preconditioning provides neuroprotection against stroke by regulating the expression of the TLR4 signalling pathway to alleviate microglial activation. Sci Rep 2015; 5:11445. [PMID: 26086415 PMCID: PMC4471883 DOI: 10.1038/srep11445] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 05/20/2015] [Indexed: 01/05/2023] Open
Abstract
Excessive microglial activation often contributes to inflammation-mediated neurotoxicity in the ischemic penumbra during the acute stage of ischemic stroke. Toll-like receptor 4 (TLR4) has been reported to induce microglial activation via the NF-κB pathway. Isoflurane preconditioning (IP) can provide neuroprotection and inhibit microglial activation. In this study, we investigated the roles of the TLR4 signalling pathway in IP to exert neuroprotection following ischemic stroke in vivo and in vitro. The results showed that 2% IP alleviated neurological deficits, reduced the infarct volume, attenuated apoptosis and weakened microglial activation in the ischemic penumbra. Furthermore, IP down-regulated the expression of HSP 60, TLR4 and MyD88 and up-regulated inhibitor of IκB-α expression compared with I/R group in vivo. In vitro, 2% IP and a specific inhibitor of TLR4, CLI-095, down-regulated the expression of TLR4, MyD88, IL-1β, TNF-α and Bax, and up-regulated IκB-α and Bcl-2 expression compared with OGD group. Moreover, IP and CLI-095 attenuated microglial activation-induced neuronal apoptosis, and overexpression of the TLR4 gene reversed the neuroprotective effects of IP. In conclusion, IP provided neuroprotection by regulating TLR4 expression directly, alleviating microglial activation and neuroinflammation. Thus, inhibiting the activation of microglial activation via TLR4 may be a new avenue for stroke treatment.
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Affiliation(s)
- Meiyan Sun
- Department of Anesthesiology, Tangdu Hospital, Fourth Military Medical University, Xi'an 710038, China
| | - Bin Deng
- Department of Anesthesiology, Tangdu Hospital, Fourth Military Medical University, Xi'an 710038, China.,State Key Laboratory of Military Stomatology, Department of Anesthesiology, School of Stomatology, Fourth Military Medical University, Xi'an 710032, China
| | - Xiaoyong Zhao
- Department of Anesthesiology, Tangdu Hospital, Fourth Military Medical University, Xi'an 710038, China.,Department of Anesthesiology, Weifang Medical University, Weifang, Shandong, 261053, China
| | - Changjun Gao
- Department of Anesthesiology, Tangdu Hospital, Fourth Military Medical University, Xi'an 710038, China
| | - Lu Yang
- Department of Anesthesiology, Tangdu Hospital, Fourth Military Medical University, Xi'an 710038, China
| | - Hui Zhao
- Department of Anesthesiology, Tangdu Hospital, Fourth Military Medical University, Xi'an 710038, China
| | - Daihua Yu
- Department of Anesthesiology, Tangdu Hospital, Fourth Military Medical University, Xi'an 710038, China
| | - Feng Zhang
- Department of Medical Administration, Lintong Sanatorium of PLA Lanzhou Military District, Lintong, Xi'an, 710600, China
| | - Lixian Xu
- State Key Laboratory of Military Stomatology, Department of Anesthesiology, School of Stomatology, Fourth Military Medical University, Xi'an 710032, China
| | - Lei Chen
- Department of Gynaecology and Obstetrics, Nave General Hospital, Beijing, 100059, China
| | - Xude Sun
- Department of Anesthesiology, Tangdu Hospital, Fourth Military Medical University, Xi'an 710038, China
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