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Wang L, Wang K, Chen Y, Zhang X, Xu W, Dong Z, Wang Y. NLRP3 Inflammasome Inhibition After Pilocarpine-Induced Status Epilepticus Attenuates Chronic Inflammation in Epileptic Mice. J Inflamm Res 2024; 17:6143-6158. [PMID: 39262652 PMCID: PMC11389722 DOI: 10.2147/jir.s469451] [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: 03/18/2024] [Accepted: 08/22/2024] [Indexed: 09/13/2024] Open
Abstract
Objective To investigate the effects of inhibiting the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome on neuronal damage and chronic pro-inflammatory responses during epileptogenesis in a mouse model of pilocarpine-induced status epilepticus (SE). Methods Mice were randomly allocated into three groups: control, SE, and SE + MCC 950. The expression patterns of M1 and M2 microglial biomarkers in the hippocampus were quantified using Western blotting, quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and immunofluorescence staining. Additionally, seizure susceptibility, video-electroencephalography recording, Morris water maze test, and brain immunofluorescence staining were performed to evaluate the epileptic brain 4 weeks post-SE. Results Within 72 hours post-SE, hippocampal microglia demonstrated a preferential polarization towards the M1 phenotype, a trend that was mitigated by NLRP3 inflammasome inhibition. During epileptogenesis, SE mice treated with NLRP3 inflammasome inhibition exhibited reduced neuronal damage, improved cognitive function, decreased seizure susceptibility, and attenuated chronic pro-inflammatory responses. Conclusion Inhibition of NLRP3 inflammasome post-SE effectively ameliorates neuronal loss, seizure susceptibility, and cognitive dysfunction during epileptogenesis. This neuroprotective effect may be mediated through the mitigation of chronic pro-inflammatory responses within the epileptic brain.
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Affiliation(s)
- Lei Wang
- Department of Neurology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui Province, 230000, People's Republic of China
| | - Kai Wang
- Department of Neurology, The Third Affiliated Hospital of Anhui Medical University, Hefei, Anhui Province, 230000, People's Republic of China
| | - Yuwen Chen
- Department of Neurology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui Province, 230000, People's Republic of China
| | - Xiaoyu Zhang
- Department of Neurology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui Province, 230000, People's Republic of China
- Department of Neurology, Anhui Public Health Clinical Center, Hefei, Anhui Province, 230000, People's Republic of China
| | - Wenhao Xu
- Department of Neurology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui Province, 230000, People's Republic of China
- Department of Neurology, Anhui Public Health Clinical Center, Hefei, Anhui Province, 230000, People's Republic of China
| | - Zhong Dong
- Department of Neurology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui Province, 230000, People's Republic of China
- Department of Neurology, Anhui Public Health Clinical Center, Hefei, Anhui Province, 230000, People's Republic of China
| | - Yu Wang
- Department of Neurology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui Province, 230000, People's Republic of China
- Department of Neurology, Anhui Public Health Clinical Center, Hefei, Anhui Province, 230000, People's Republic of China
- Department of Neurology, Anqing First People's Hospital Affiliated to Anhui Medical University, Anqing, Anhui Province, 246000, People's Republic of China
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2
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Soares AR, Picciotto MR. Nicotinic regulation of microglia: potential contributions to addiction. J Neural Transm (Vienna) 2024; 131:425-435. [PMID: 37778006 PMCID: PMC11189589 DOI: 10.1007/s00702-023-02703-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 09/22/2023] [Indexed: 10/03/2023]
Abstract
Clinical and preclinical studies have identified immunosuppressive effects of nicotine, with potential implications for treating nicotine addiction. Here we review how nicotine can regulate microglia, the resident macrophages in the brain, and corresponding effects of nicotine on neuroimmune signaling. There is significant evidence that activation of α7 nicotinic acetylcholine receptors (nAChRs) on microglia can trigger an anti-inflammatory cascade that alters microglial polarization and activity, cytokine release, and intracellular calcium concentrations, leading to neuroprotection. These anti-inflammatory effects of nicotine-dependent α7 nAChR signaling are lost during withdrawal, suggesting that neuroimmune signaling is potentiated during abstinence, and thus, heightened microglial activity may drive circuit disruption that contributes to withdrawal symptoms and hyperkatifeia. In sum, the clinical literature has highlighted immunomodulatory effects of nicotine and the potential for anti-inflammatory compounds to treat addiction. The preclinical literature investigating the underlying mechanisms points to a role of microglial engagement in the circuit dysregulation and behavioral changes that occur during nicotine addiction and withdrawal, driven, at least in part, by activation of α7 nAChRs on microglia. Specifically targeting microglial signaling may help alleviate withdrawal symptoms in people with nicotine dependence and help to promote abstinence.
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Affiliation(s)
- Alexa R Soares
- Department of Psychiatry, Yale University, 34 Park Street-3rd floor Research, New Haven, CT, 06508, USA
- Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT, 06508, USA
| | - Marina R Picciotto
- Department of Psychiatry, Yale University, 34 Park Street-3rd floor Research, New Haven, CT, 06508, USA.
- Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT, 06508, USA.
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3
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Wedn AM, El-Bassossy HM, Eid AH, El-Mas MM. Modulation of preeclampsia by the cholinergic anti-inflammatory pathway: Therapeutic perspectives. Biochem Pharmacol 2021; 192:114703. [PMID: 34324867 DOI: 10.1016/j.bcp.2021.114703] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 07/21/2021] [Accepted: 07/22/2021] [Indexed: 12/12/2022]
Abstract
The cholinergic anti-inflammatory pathway (CAP) is vital for the orchestration of the immune and inflammatory responses under normal and challenged conditions. Over the past two decades, peripheral and central circuits of CAP have been shown to be critically involved in dampening the inflammatory reaction in a wide array of inflammatory disorders. Additionally, emerging evidence supports a key role for CAP in the regulation of the female reproductive system during gestation as well as in the advent of serious pregnancy-related inflammatory insults such as preeclampsia (PE). Within this framework, the modulatory action of CAP encompasses the perinatal maternal and fetal adverse consequences that surface due to antenatal PE programming. Albeit, a considerable gap still exists in our knowledge of the precise cellular and molecular underpinnings of PE/CAP interaction, which hampered global efforts in safeguarding effective preventive or therapeutic measures against PE complications. Here, we summarize reports in the literature regarding the roles of peripheral and reflex cholinergic neuroinflammatory pathways of nicotinic acetylcholine receptors (nAChRs) in reprogramming PE complications in mothers and their progenies. The possible contributions of α7-nAChRs, cholinesterases, immune cells, adhesion molecules, angiogenesis, and endothelial dysfunction to the interaction have also been reviewed.
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Affiliation(s)
- Abdalla M Wedn
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt
| | - Hany M El-Bassossy
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Zagazig University, Zagazig, Egypt
| | - Ali H Eid
- Department of Basic Medical Sciences, College of Medicine, QU Health, Qatar University, Doha, Qatar; Biomedical and Pharmaceutical Research Unit, QU Health, Qatar University, Doha, Qatar
| | - Mahmoud M El-Mas
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt; Department of Pharmacology and Toxicology, Faculty of Medicine, Kuwait University, Kuwait.
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4
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Zhou L, Tao X, Pang G, Mu M, Sun Q, Liu F, Hu Y, Tao H, Li B, Xu K. Maternal Nicotine Exposure Alters Hippocampal Microglia Polarization and Promotes Anti-inflammatory Signaling in Juvenile Offspring in Mice. Front Pharmacol 2021; 12:661304. [PMID: 34045967 PMCID: PMC8144443 DOI: 10.3389/fphar.2021.661304] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 04/26/2021] [Indexed: 12/15/2022] Open
Abstract
Accumulating evidence reveal that maternal smoking or perinatal nicotine replacement therapy impairs hippocampal neurogenesis, neural development, and cognitive behaviors in the offspring. Microglia is a source of non-neural regulation of neuronal development and postnatal neurogenesis. In this study, we explored the impact of nicotine on the microglia during the development of hippocampus. Developmental nicotine exposure in a mouse model was conducted by supplementing nicotine in the drinking water to mother mice during gestation and lactation period. We found that juvenile offspring with maternal nicotine exposure presented physical and neurobehavioral development delay and an increase in anxiety-like behavior in the open field test on postnatal day (PND) 20. To further detect possible developmental neurotoxic effects of nicotine in offspring and underlying mechanism, whole genome microarray analysis of the expression profile of the hippocampus was performed on postnatal day 20. Significant alterations in the expression of genes related to inflammatory, neurotransmitter, and synapsis were observed in the hippocampus after maternal nicotine exposure, as compared to the vehicle control. Concurrently, an increase in microglial markers and the presence of M2 polarity state in the hippocampus of the nicotine offspring were observed by histological analysis and confocal z-stacking scanning. The M2 microglial polarization state was further confirmed with in vitro primary microglia culture by cytokine array, and double-positive expression of BDNF/Iba1 in microglia by immunohistochemical staining in the juvenile offspring hippocampus was visualized. We also found that nicotine offspring showed an increase of neurite length in the molecular layer and CA1 by Tuj1 staining, as well as an increase in the expression of synapse associated protein, PSD95, but the expression of NeuroD1 in CA1 and CA3 reduced. In summary, maternal nicotine exposure dysregulates immune-related genes expression by skewing the polarity of M2 microglia in the hippocampus, which may cause abnormal cognitive and behavioral performance in the offspring.
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Affiliation(s)
- Li Zhou
- Center for Medical Research, School of Medicine, Anhui University of Science and Technology, Huainan, China
| | - Xinrong Tao
- Center for Medical Research, School of Medicine, Anhui University of Science and Technology, Huainan, China.,Key Laboratory of Industrial Dust Control and Occupational Health, Ministry of Education, Anhui University of Science and Technology, Huainan, China.,Key Laboratory of Industrial Dust Deep Reduction and Occupational Health and Safety, Anhui Higher Education Institutes, Anhui University of Science and Technology, Huainan, China.,Engineering Laboratory of Occupational Safety and Health, Anhui Province, Anhui University of Science and Technology, Huainan, China
| | - Gang Pang
- College of Basic Medical Science, Anhui Medical University, Hefei, China
| | - Min Mu
- Center for Medical Research, School of Medicine, Anhui University of Science and Technology, Huainan, China.,Key Laboratory of Industrial Dust Control and Occupational Health, Ministry of Education, Anhui University of Science and Technology, Huainan, China.,Key Laboratory of Industrial Dust Deep Reduction and Occupational Health and Safety, Anhui Higher Education Institutes, Anhui University of Science and Technology, Huainan, China.,Engineering Laboratory of Occupational Safety and Health, Anhui Province, Anhui University of Science and Technology, Huainan, China
| | - Qixian Sun
- Center for Medical Research, School of Medicine, Anhui University of Science and Technology, Huainan, China
| | - Fei Liu
- Center for Medical Research, School of Medicine, Anhui University of Science and Technology, Huainan, China
| | - Yuting Hu
- Center for Medical Research, School of Medicine, Anhui University of Science and Technology, Huainan, China
| | - Huihui Tao
- Center for Medical Research, School of Medicine, Anhui University of Science and Technology, Huainan, China.,Key Laboratory of Industrial Dust Control and Occupational Health, Ministry of Education, Anhui University of Science and Technology, Huainan, China.,Key Laboratory of Industrial Dust Deep Reduction and Occupational Health and Safety, Anhui Higher Education Institutes, Anhui University of Science and Technology, Huainan, China.,Engineering Laboratory of Occupational Safety and Health, Anhui Province, Anhui University of Science and Technology, Huainan, China
| | - Bing Li
- Center for Medical Research, School of Medicine, Anhui University of Science and Technology, Huainan, China
| | - Keyi Xu
- Center for Medical Research, School of Medicine, Anhui University of Science and Technology, Huainan, China.,Key Laboratory of Industrial Dust Control and Occupational Health, Ministry of Education, Anhui University of Science and Technology, Huainan, China.,Key Laboratory of Industrial Dust Deep Reduction and Occupational Health and Safety, Anhui Higher Education Institutes, Anhui University of Science and Technology, Huainan, China.,Engineering Laboratory of Occupational Safety and Health, Anhui Province, Anhui University of Science and Technology, Huainan, China
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5
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Han X, Li W, Li P, Zheng Z, Lin B, Zhou B, Guo K, He P, Yang J. Stimulation of α7 Nicotinic Acetylcholine Receptor by Nicotine Suppresses Decidual M1 Macrophage Polarization Against Inflammation in Lipopolysaccharide-Induced Preeclampsia-Like Mouse Model. Front Immunol 2021; 12:642071. [PMID: 33995360 PMCID: PMC8113862 DOI: 10.3389/fimmu.2021.642071] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 03/30/2021] [Indexed: 12/31/2022] Open
Abstract
Changes in decidual macrophage polarization affect local inflammatory microenvironment and lead to adverse pregnancy outcomes. However, the regulatory mechanism of macrophage polarization in preeclampsia (PE) remains unclear. In this study, we found that α7nAChR expression was significantly down-regulated in decidual macrophages in PE patients compared to normal pregnant women, accompanied by a reduced proportion of M2 phenotype and an increased proportion of M1 phenotype; these results suggested that the reduced α7nAChR activity might contribute to changes in the polarization of decidual macrophages. Then, we further investigated the regulatory role of α7nAChR activation by nicotine on decidual macrophage polarization and placental remodeling in the PE-like mouse model. The PE mice were obtained by i.p. injection of 10 µg/kg lipopolysaccharide (LPS) gestational day (GD) 13, and 40 µg/kg LPS daily until GD16. Subcutaneous injection of 1.0 mg/kg nicotine was administrated from GD14 to GD18. Nicotine treatment increased the decreased M2 phenotype and inhibited the increased M1 phenotype in decidua of pregnant mice induced by LPS. The levels of pro-inflammatory cytokines in decidua were higher but the levels of anti-inflammatory cytokines were lower in PE mice compared to the controls, nicotine reversed these changes. The level of choline acetyltransferase (CHAT) was reduced in the LPS-treated group, it was increased following nicotine treatment. Damage of spiral artery remodeling and down-regulation of markers related to trophoblast invasion in placentas were found in PE mice; nicotine improved these pathological structures of placentas. α-bungarotoxin (α-BGT) which is specific antagonist for α7nAChR could abolish the effects of nicotine on decidual macrophage polarization, trophoblast arrangement and vascular structure in placental tissue in PE mice. These results suggest that α7nAChR plays an important regulatory role in maternal-fetal inflammation and placental remodeling in preeclampsia and may provide a theoretical basis for the discovery of new strategies for preeclampsia.
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Affiliation(s)
- Xinjia Han
- Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Wei Li
- Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Ping Li
- Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Zheng Zheng
- Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Baohua Lin
- Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Bei Zhou
- Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Kaimin Guo
- Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Ping He
- Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Jinying Yang
- Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
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6
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Sun P, Liu DG, Ye XM. Nicotinic Acetylcholine Receptor α7 Subunit Is an Essential Regulator of Seizure Susceptibility. Front Neurol 2021; 12:656752. [PMID: 33912128 PMCID: PMC8072353 DOI: 10.3389/fneur.2021.656752] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 03/12/2021] [Indexed: 01/16/2023] Open
Abstract
A large body of data has confirmed that α7 nicotinic acetylcholine receptors (nAChRs) play a pivotal role in cognition, memory, and other neuropsychiatric diseases, but their effect on seizure susceptibility in C57BL/6 wild-type mice is not fully understood. Here, we showed that decreased activity of α7 nAChRs could increase the excitability of CA1 pyramidal neurons and shorten the onset time of epilepsy in pilocarpine-induced mouse models. However, compared with the control group, there was no apparent effect of increasing the activity of α7 nAChRs. Moreover, the expression of α7 nAChRs is downregulated in human epileptogenic tissues. Taken together, our findings indicate that α7 nAChR is an essential regulator of seizure susceptibility.
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Affiliation(s)
- Peng Sun
- Rehabilitation & Sports Medicine Research Institute of Zhejiang Province, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, China
| | - Da-Gang Liu
- Department of Neurosurgery Medicine, Weihai Central Hospital, Weihai, China
| | - Xiang-Ming Ye
- Rehabilitation & Sports Medicine Research Institute of Zhejiang Province, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, China
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7
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Heldt NA, Reichenbach N, McGary HM, Persidsky Y. Effects of Electronic Nicotine Delivery Systems and Cigarettes on Systemic Circulation and Blood-Brain Barrier: Implications for Cognitive Decline. THE AMERICAN JOURNAL OF PATHOLOGY 2020; 191:243-255. [PMID: 33285126 DOI: 10.1016/j.ajpath.2020.11.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 10/23/2020] [Accepted: 11/06/2020] [Indexed: 12/17/2022]
Abstract
Electronic nicotine delivery systems (often known as e-cigarettes) are a novel tobacco product with growing popularity, particularly among younger demographics. The implications for public health are twofold, as these products may represent a novel source of tobacco-associated disease but may also provide a harm reduction strategy for current tobacco users. There is increasing recognition that e-cigarettes impact vascular function across multiple organ systems. Herein, we provide a comparison of evidence regarding the role of e-cigarettes versus combustible tobacco in vascular disease and implications for blood-brain barrier dysfunction and cognitive decline. Multiple non-nicotinic components of tobacco smoke have been identified in e-cigarette aerosol, and their involvement in vascular disease is discussed. In addition, nicotine and nicotinic signaling may modulate peripheral immune and endothelial cell populations in a highly context-dependent manner. Direct preclinical evidence for electronic nicotine delivery system-associated neurovascular impairment is provided, and a model is proposed in which non-nicotinic elements exert a proinflammatory effect that is functionally antagonized by the presence of nicotine.
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Affiliation(s)
- Nathan A Heldt
- Department of Pathology and Laboratory Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania; Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania.
| | - Nancy Reichenbach
- Department of Pathology and Laboratory Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania
| | - Hannah M McGary
- Department of Pathology and Laboratory Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania
| | - Yuri Persidsky
- Department of Pathology and Laboratory Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania; Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania.
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8
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Fang X, Liang Y, Chen D, Liu Y, Xie M, Zhang W. Contribution of excess inflammation to a possible rat model of eclamptic reversible posterior leukoencephalopathy syndrome induced by lipopolysaccharide and pentylenetetrazol: A preliminary study. Cytokine 2020; 135:155212. [DOI: 10.1016/j.cyto.2020.155212] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 06/15/2020] [Accepted: 07/13/2020] [Indexed: 12/01/2022]
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9
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Kumar M, Adeluyi A, Anderson EL, Turner JR. Glial cells as therapeutic targets for smoking cessation. Neuropharmacology 2020; 175:108157. [PMID: 32461156 PMCID: PMC7791555 DOI: 10.1016/j.neuropharm.2020.108157] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 05/19/2020] [Accepted: 05/20/2020] [Indexed: 12/17/2022]
Abstract
Smoking remains the leading cause of morbidity and mortality in the United States, with less than 5% of smokers attempting to quit succeeding. This low smoking cessation success rate is thought to be due to the long-term adaptations and alterations in synaptic plasticity that occur following chronic nicotine exposure and withdrawal. Glial cells have recently emerged as active players in the development of dependence phenotypes due to their roles in modulating neuronal functions and synaptic plasticity. Fundamental studies have demonstrated that microglia and astrocytes are crucial for synapse formation and elimination in the developing brain, likely contributing to why glial dysfunction is implicated in numerous neurological and psychiatric disorders. Recently, there is increasing evidence for the involvement of glial cells in drug dependence and its associated behavioral manifestations. This review summarizes the newly evaluated role of microglia and astrocytes as molecular drivers of nicotine dependence and withdrawal phenotypes. This article is part of the special issue on 'Contemporary Advances in Nicotine Neuropharmacology.
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Affiliation(s)
- Mohit Kumar
- Department of Pharmaceutical Sciences, University of Kentucky College of Pharmacy, Lexington, KY, USA.
| | - Adewale Adeluyi
- Department of Pharmaceutical Sciences, University of Kentucky College of Pharmacy, Lexington, KY, USA; Ann Romney Center for Neurologic Disease, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
| | - Erin L Anderson
- Department of Drug Discovery and Biomedical Sciences, South Carolina College of Pharmacy, University of South Carolina, Columbia, USA.
| | - Jill R Turner
- Department of Pharmaceutical Sciences, University of Kentucky College of Pharmacy, Lexington, KY, USA.
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10
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Li X, Zhou B, Han X, Liu H. Effect of nicotine on placental inflammation and apoptosis in preeclampsia-like model. Life Sci 2020; 261:118314. [PMID: 32835699 DOI: 10.1016/j.lfs.2020.118314] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 08/10/2020] [Accepted: 08/19/2020] [Indexed: 02/07/2023]
Abstract
AIMS Placental tissues from patients with preeclampsia (PE) and in the lipopolysaccharide (LPS)-induced PE-like model were used to investigate the implication of placental inflammation and apoptosis in PE. Whether the beneficial effects of nicotine are related to inhibition of placental inflammation and apoptosis in the PE-like model were investigated. MAIN METHODS Placental apoptosis was detected in PE patients and the PE-like rat model by TUNEL staining. Changes in the number of CD68+ macrophages in placental tissues from PE patients were detected by immunofluorescent staining. The mRNA expression of the pro-inflammatory cytokines tumor necrosis factor alpha (TNF-α), interleukin (IL-1β), MCP-1, and proteins involved in extrinsic or intrinsic apoptosis signaling in the PE-like model was determined by qRT-PCR; immunofluorescent staining was used to detect the expression of TNF-α receptor (TNFR1), MCP-1 and apoptosis-related proteins. KEY FINDINGS Placental apoptosis was increased in both PE patients and the PE-like model, more macrophages infiltrated into placenta in PE patients. A significant upregulation in mRNA expression of TNF-α, IL-1β, MCP-1, and caspase 3, caspase 8, caspase 9 was found in the PE-like rats compared to the control animals, the immunoreactivity of placental MCP-1, TNFR1, and apoptosis-related proteins (caspase 3, caspase 8, caspase 9, Bax) was also enhanced; nicotine treatment significantly reversed those changes. SIGNIFICANCE Our data suggests that the protective effects of nicotine are associated with inhibiting placenta inflammation and apoptosis, and nicotine might be a potentially therapeutic candidate for preventing preeclampsia.
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Affiliation(s)
- Xin Li
- First Affiliated Hospital of Jinan University, Guangzhou, China; Department of Obstetrics and Gynecology, Anhui Provincial Hospital, Anhui Medical University, Hefei, China; Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Bei Zhou
- Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Xinjia Han
- Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China.
| | - Huishu Liu
- Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China.
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11
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Han X, Zhou N, Hu H, Li X, Liu H. Nicotine Alleviates Cortical Neuronal Injury by Suppressing Neuroinflammation and Upregulating Neuronal PI3K-AKT Signaling in an Eclampsia-Like Seizure Model. Neurotox Res 2020; 38:665-681. [PMID: 32767216 DOI: 10.1007/s12640-020-00265-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 07/27/2020] [Accepted: 07/28/2020] [Indexed: 12/12/2022]
Abstract
Our previous studies showed that treatment with alpha7 nicotinic acetylcholine receptor (α7nAChR) agonist nicotine could alleviate systemic inflammation and reduce neuronal loss in the hippocampus and seizure severity in eclampsia. In this study, we further investigated whether there is also neuronal damage in the cortex after eclamptic seizure, elucidated the potential mechanisms underlying the neuroprotective roles of nicotine in eclampsia. Retrospective analysis of MRI data of severe preeclampsia (SPE) patients was conducted. A preeclampsia model was established by lipopolysaccharide injection (PE group), and pentylenetetrazol was used to induce eclamptic seizure (E group). α7nAChR agonist nicotine and its antagonist (α-BGT) and PI3K inhibitor wortmannin were used for drug administration. Neuronal damage was detected by Nissl staining, and changes in neuroinflammation, neuronal apoptosis, α7nAChR expression, and PI3K-AKT signaling on cortical neurons were detected by immunohistochemistry and western blotting. MRI images showed that most abnormal signals from the brain of SPE patients were located in the cortex. The neuron survival ratio was lower in the cortex than in the hippocampus within the E group; such ratios in the cortex were significantly lower in the E and PE groups compared with those of the control group. Nicotine markedly decreased the production of inflammatory cytokines and microglial activation in the cortex of the E group. Moreover, nicotine increased p-AKT levels and decreased cleaved caspase-3 levels in cortical neurons. Treatment with α-BGT reversed effects of nicotine. Wortmannin also blocked the anti-neuronal apoptosis action of nicotine. Our results suggest that nicotine protects against neuronal injury in the cortex following eclampsia possibly by inhibiting neuroinflammation and activating neuronal PI3K-AKT pathway.
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Affiliation(s)
- Xinjia Han
- Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Road, Guangzhou, 510623, China
| | - Ning Zhou
- Department of Radiology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Huiping Hu
- Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Road, Guangzhou, 510623, China
| | - Xin Li
- Department of Obstetrics and Gynaecology, The First Affiliated Hospital of USTC, Anhui Provincial Hospital, Hefei, China
| | - Huishu Liu
- Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Road, Guangzhou, 510623, China.
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12
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Heldt NA, Seliga A, Winfield M, Gajghate S, Reichenbach N, Yu X, Rom S, Tenneti A, May D, Gregory BD, Persidsky Y. Electronic cigarette exposure disrupts blood-brain barrier integrity and promotes neuroinflammation. Brain Behav Immun 2020; 88:363-380. [PMID: 32243899 PMCID: PMC7899242 DOI: 10.1016/j.bbi.2020.03.034] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 03/17/2020] [Accepted: 03/30/2020] [Indexed: 12/23/2022] Open
Abstract
Electronic cigarette (e-cigarette) use has grown substantially since inception, particularly among adolescents and combustible tobacco users. Several cigarette smoke constituents with known neurovascular effect are present in e-cigarette liquids or formed during the vapor generation. The present study establishes inhaled models of cigarette and e-cigarette use with normalized nicotine delivery, then characterizes the impact on blood-brain barrier (BBB) function. Sequencing of microvessel RNA following exposure revealed downregulation of several genes with critical roles in BBB function. Reduced protein expression of Occludin and Glut1 is also observed at the tight junction in all groups following exposure. Pro-inflammatory changes in leukocyte-endothelial cell interaction are also noted, and mice exposed to nicotine-free e-cigarettes have impaired novel object recognition performance. On this basis, it is concluded that long term e-cigarette use may adversely impact neurovascular health. The observed effects are noted to be partly independent of nicotine content and nicotine may even serve to moderate the effects of non-nicotinic components on the blood-brain barrier.
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Affiliation(s)
- Nathan A Heldt
- Department of Pathology and Laboratory Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA; Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA.
| | - Alecia Seliga
- Department of Pathology and Laboratory Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Malika Winfield
- Department of Pathology and Laboratory Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Sachin Gajghate
- Department of Pathology and Laboratory Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Nancy Reichenbach
- Department of Pathology and Laboratory Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Xiang Yu
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Slava Rom
- Department of Pathology and Laboratory Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA; Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Amogha Tenneti
- Department of Pathology and Laboratory Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Dana May
- Department of Pathology and Laboratory Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Brian D Gregory
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Yuri Persidsky
- Department of Pathology and Laboratory Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA; Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA.
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13
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Magnesium sulfate prophylaxis attenuates the postpartum effects of preeclampsia by promoting M2 macrophage polarization. Hypertens Res 2020; 44:13-22. [PMID: 32719464 DOI: 10.1038/s41440-020-0511-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 06/13/2020] [Accepted: 06/18/2020] [Indexed: 12/12/2022]
Abstract
Preeclampsia is a complex disorder that is characterized by new onset hypertension and proteinuria at or after 20 weeks of gestation. Preeclampsia is a leading cause of maternal and fetal morbidity and mortality. MgSO4 is commonly used to treat severe preeclampsia, but its mechanism of action is poorly understood, and investigations into the effects of MgSO4 during the postpartum period are lacking. In this study, timed-pregnant Sprague-Dawley rats received low-dose lipopolysaccharide (LPS) on gestational day 14 to induce preeclampsia. Maternal and fetal outcomes and the macrophage profile 1 week after delivery were explored. On postpartum day (PD) 7, the maternal systolic blood pressure and urinary protein level were significantly increased, the number of M1 macrophages was increased and the number of M2 macrophages was decreased in the maternal kidney and brain; the median duration of gestation, the number of live fetuses, and the fetal weight/placenta weight ratio were significantly decreased; and the percentage of growth-restricted pups and fetal mortality were significantly increased in preeclampsia rats compared to normal pregnant control rats. Prophylactic MgSO4 decreased blood pressure at PD7, improved pregnancy outcomes, and promoted the polarization of M2 macrophages in the kidney and of M2 microglia in the brain of preeclampsia rats. These findings confirm that the pathophysiology of preeclampsia involves the dysregulation of the inflammatory response and the activation of M1 macrophages in several target organs during pregnancy. MgSO4 prophylaxis attenuates the postpartum effects of preeclampsia by promoting M2 macrophage polarization in the maternal kidney and brain.
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14
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Cyclosporin A ameliorates eclampsia seizure through reducing systemic inflammation in an eclampsia-like rat model. Hypertens Res 2020; 43:263-270. [PMID: 31932642 DOI: 10.1038/s41440-019-0387-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 06/05/2019] [Accepted: 06/19/2019] [Indexed: 12/18/2022]
Abstract
Our previous studies have shown that the maternal hyperinflammatory response in pre-eclampsia lowered the eclampsia-like seizure threshold. Cyclosporin A (CsA), which is an effective immunosuppressant, could attenuate the inflammatory responses in LPS-induced pre-eclampsia rats. Here, we hypothesized that CsA may ameliorate seizure severity through reducing systemic inflammation in pre-eclampsia/eclampsia. In the current study, the effects of CsA on pre-eclampsia manifestation, eclampsia-like seizure activities and systemic inflammation were examined in a pre-eclampsia model. Pregnant rats were given an intraperitoneal injection of the epileptogenic drug pentylenetetrazol (PTZ) following a tail vein injection of lipopolysaccharide to establish the eclampsia-like seizure model. CsA (5 mg/kg) was administered intravenously through the tail after LPS infusion. Mean systolic blood pressure and proteinuria in pre-eclampsia were detected. After PTZ injection, seizure activity was assessed, inflammatory responses were determined and pregnancy outcomes were analyzed. The results showed that CsA treatment significantly decreased blood pressure and proteinuria and increased the fetal and placental weight (P < 0.01). Meanwhile, CsA treatment significantly reduced serum IL-1β, TNF-α, and IL-17 levels (P < 0.01), decreased the seizure scores and prolonged the latency to seizure (P < 0.01). CsA effectively attenuated pre-eclampsia manifestation and eclampsia-like seizure severity. In addition, CsA treatment significantly reduced the inflammatory cytokine levels and improved pregnancy outcomes following eclampsia-like seizures. The decreased inflammatory cytokines in pre-eclampsia are coincident with attenuated pre-eclampsia manifestation after CsA treatment, suggesting that CsA treatment might decrease the eclampsia-like seizure severity through decreasing systemic inflammation in pre-eclasmpsia/eclampsia.
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15
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Bergman L, Torres-Vergara P, Penny J, Wikström J, Nelander M, Leon J, Tolcher M, Roberts JM, Wikström AK, Escudero C. Investigating Maternal Brain Alterations in Preeclampsia: the Need for a Multidisciplinary Effort. Curr Hypertens Rep 2019; 21:72. [PMID: 31375930 DOI: 10.1007/s11906-019-0977-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
PURPOSE OF REVIEW To provide insight into the mechanisms underlying cerebral pathophysiology and to highlight possible methods for evaluation, screening, and surveillance of cerebral complications in preeclampsia. RECENT FINDINGS The pathophysiology of eclampsia remains enigmatic. Animal studies show that the cerebral circulation in pregnancy and preeclampsia might be affected with increased permeability over the blood-brain barrier and altered cerebral blood flow due to impaired cerebral autoregulation. The increased blood pressure cannot be the only underlying cause of eclampsia and cerebral edema, since some cases of eclampsia arise without simultaneous hypertension. Findings from animal studies need to be confirmed in human tissues. Evaluation of brain alterations in preeclampsia and eclampsia is challenging and demands a multidisciplinary collaboration, since no single method can accurately and fully describe how preeclampsia affects the brain. Cerebral complications of preeclampsia are significant factors in maternal morbidity and mortality worldwide. No single method can accurately describe the full picture of how preeclampsia affects the brain vasculature and parenchyma. We recommend an international and multidisciplinary effort not only to overcome the issue of limited sample availability but also to optimize the quality of research.
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Affiliation(s)
- Lina Bergman
- Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden.
- Center for Clinical Research Dalarna, Falun, Uppsala, Sweden.
| | - Pablo Torres-Vergara
- Pharmacy Department, Faculty of Pharmacy, Universidad de Concepción, Concepción, Chile
- Group of Research and Innovation in Vascular Health (GRIVAS Health), Chillán, Chile
| | - Jeffrey Penny
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Johan Wikström
- Department of Radiology, Uppsala University, Uppsala, Sweden
| | - Maria Nelander
- Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden
| | - Jose Leon
- Group of Research and Innovation in Vascular Health (GRIVAS Health), Chillán, Chile
- Vascular Physiology Laboratory, Group of Investigation in Tumor Angiogenesis, (LFV-GIANT), Department of Basic Sciences, Faculty of Sciences, Universidad del Bío-Bío, Chillán, Chile
| | - Mary Tolcher
- Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden
| | - James M Roberts
- Magee Womens Research Institute, Dept of Obstetrics Gynecology and Reproductive Sciences, Epidemiology and Clinical and Translational Research, University of Pittsburgh, Pittsburgh, PA, USA
| | - Anna-Karin Wikström
- Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden
| | - Carlos Escudero
- Group of Research and Innovation in Vascular Health (GRIVAS Health), Chillán, Chile.
- Vascular Physiology Laboratory, Group of Investigation in Tumor Angiogenesis, (LFV-GIANT), Department of Basic Sciences, Faculty of Sciences, Universidad del Bío-Bío, Chillán, Chile.
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16
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Sun Y, Ma J, Li D, Li P, Zhou X, Li Y, He Z, Qin L, Liang L, Luo X. Interleukin-10 inhibits interleukin-1β production and inflammasome activation of microglia in epileptic seizures. J Neuroinflammation 2019; 16:66. [PMID: 30922332 PMCID: PMC6437919 DOI: 10.1186/s12974-019-1452-1] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 03/15/2019] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Microglia are important for secreting chemical mediators of inflammatory responses in the central nervous system. Interleukin (IL)-10 and IL-1β secreted by glial cells support neuronal functions, but the related mechanisms remain vague. Our goal was to demonstrate the efficacy of IL-10 in suppressing IL-1β and in inflammasome activation in mice with epileptic seizure based on an epileptic-seizure mouse model. METHODS In this study, mice in which epileptic seizures were induced by administering picrotoxin (PTX) were used as a case group, and mice injected with saline were employed as the control group. The expression of nucleic acids, cytokines, or signaling pathways was detected by reverse transcription-polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA), flow cytometry, and Western blotting. RESULTS Our results demonstrated that IL-10 inhibits IL-1β production through two distinct mechanisms: (1) Treatment with lipopolysaccharides (LPS) results in IL-10 overexpression in microglia and reduced NLRP3 inflammasome activity, thus inhibiting caspase-1-related IL-1β maturation; (2) next, autocrine IL-10 was found to subsequently promote signal transducer and activator of transcription-3 (STAT-3), reducing amounts of pro-IL-1β. CONCLUSIONS Our results indicate that IL-10 is potentially effective in the treatment of inflammation encephalopathy, and suggest the potential usefulness of IL-10 for treating autoimmune or inflammatory ailments.
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Affiliation(s)
- Yi Sun
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, China.,Department of Pediatric, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, China
| | - Jiangjun Ma
- Department of Molecular Diagnostics, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China
| | - Dongfang Li
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, China.,Department of Pediatric, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, China
| | - Pinggan Li
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, China.,Department of Pediatric, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, China
| | - Xiaolin Zhou
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, China.,Department of Pediatric, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, China
| | - Yu Li
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, China.,Department of Pediatric, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, China
| | - Zhanwen He
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, China.,Department of Pediatric, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, China
| | - Lijun Qin
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, China.,Department of Pediatric, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, China
| | - Liyang Liang
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, China.,Department of Pediatric, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, China
| | - Xiangyang Luo
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, China. .,Department of Pediatric, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, China.
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17
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Ji L, Chen Y, Wei H, Feng H, Chang R, Yu D, Wang X, Gong X, Zhang M. Activation of alpha7 acetylcholine receptors reduces neuropathic pain by decreasing dynorphin A release from microglia. Brain Res 2019; 1715:57-65. [PMID: 30898676 DOI: 10.1016/j.brainres.2019.03.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Revised: 01/09/2019] [Accepted: 03/16/2019] [Indexed: 12/17/2022]
Abstract
Dynorphin A is increased in neuropathic pain models. Activation of α7 n acetylcholine receptor (nAchR) reduces inflammation and pain. Whether activation of α7 nAchR affects dynorphin A release is unknown. The experiments evaluated the proinflammatory effect of dynorphin A in the spinal nerve ligation-induced neuropathic pain models and the effect of α7 nAchR activation on the dynorphin A content. α7 nAchR agonist, PHA-543613 and its antagonist, methyllycaconitine citrate were used and dynorphin A content was measured after spinal nerve ligation and in microglia cultures to test the analgesic mechanisms of α7 nAchR activation. The results showed that dynorphin A content peaked 3 to 7 days after nerve injury, and dynorphin A anti-serum intrathecal injection decreased IL-β and TNF-α content a week after nerve injury. Activation of α7 nAchR by PHA-543613 alleviated neuropathic pain behaviors and decreased dynorphin A concentration in the ipsilateral spinal cords. Also, PHA-543613 decreased dynorphin A release from the microglia cultures to LPS stimulation by activation of α7 nAchR. Our results suggest that dynorphin A contribute to the development and maintenance of neuropathic pain and that decreasing dynorphin A content by activation of α7 AchR of microglia is a potential therapeutic target for treating neuropathic pain.
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Affiliation(s)
- Liu Ji
- Department of Anesthesiology, Shiyan Taihe Hospital, Affiliated Hospital of Hubei University of Medicine, Hubei, Shiyan, China; Institute of Anesthesiology, Department of Anesthesiology, Hubei University of Medicine, Hubei, Shiyan, China
| | - Yongmei Chen
- Department of Laboratory, Shiyan Taihe Hospital, Affiliated Hospital of Hubei University of Medicine, Hubei, Shiyan, China
| | - Huixia Wei
- Department of Anesthesiology, Shiyan Taihe Hospital, Affiliated Hospital of Hubei University of Medicine, Hubei, Shiyan, China; Institute of Anesthesiology, Department of Anesthesiology, Hubei University of Medicine, Hubei, Shiyan, China
| | - Hui Feng
- Department of Anesthesiology, Shiyan Taihe Hospital, Affiliated Hospital of Hubei University of Medicine, Hubei, Shiyan, China; Institute of Anesthesiology, Department of Anesthesiology, Hubei University of Medicine, Hubei, Shiyan, China
| | - Ruijie Chang
- Department of Anesthesiology, Shiyan Taihe Hospital, Affiliated Hospital of Hubei University of Medicine, Hubei, Shiyan, China; Institute of Anesthesiology, Department of Anesthesiology, Hubei University of Medicine, Hubei, Shiyan, China
| | - Di Yu
- Department of Anesthesiology, Shiyan Taihe Hospital, Affiliated Hospital of Hubei University of Medicine, Hubei, Shiyan, China; Institute of Anesthesiology, Department of Anesthesiology, Hubei University of Medicine, Hubei, Shiyan, China
| | - Xianyu Wang
- Department of Anesthesiology, Shiyan Taihe Hospital, Affiliated Hospital of Hubei University of Medicine, Hubei, Shiyan, China; Institute of Anesthesiology, Department of Anesthesiology, Hubei University of Medicine, Hubei, Shiyan, China.
| | - Xingrui Gong
- Department of Anesthesiology, Shiyan Taihe Hospital, Affiliated Hospital of Hubei University of Medicine, Hubei, Shiyan, China; Institute of Anesthesiology, Department of Anesthesiology, Hubei University of Medicine, Hubei, Shiyan, China; Department of Anesthesiology and Pediatric Clinical Pharmacology Laboratory, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Mazhong Zhang
- Department of Anesthesiology and Pediatric Clinical Pharmacology Laboratory, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
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18
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Wang L, Hu H, Morse AN, Han X, Bao J, Yang J, Chen Y, Liu H. Activation of Autophagy in Human Uterine Myometrium During Labor. Reprod Sci 2019:1933719119834351. [PMID: 30845895 DOI: 10.1177/1933719119834351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVE: The purpose of this study was to analyze the autophagy of the human uterine myometrium during the labor. METHODS: We collected uterine myometrium strips from term, singleton, nulliparous healthy women undergoing cesarean delivery before labor (nonlabor group, n = 10) or during normal labor (in-labor group, n = 10) without rupturing of membrane. The indications for cesarean delivery were breech presentation or maternal request. Transmission electron microscopy was used to observe autophagosomes. Reverse transcriptase polymerase chain reaction, immunofluorescence, and Western blot were used to quantify the messenger RNA (mRNA) and protein level of the autophagy markers LC3B, P62, and Beclin-1 in the uterine muscle strips. RESULTS: There were no differences between both groups in maternal age, body mass index, gestational week, neonatal weight, operative bleeding, and postpartum bleeding. Transmission electron micrographs showed that autophagosomes existed in myometrial tissue in both groups. There were more autophagosomes in the in-labor group than in the nonlabor group, and the difference had significance. The in-labor group had significantly greater LC3B mRNA expression but significantly lower P62 mRNA expression compared with the nonlabor group. Semiquantitative immunofluorescence in uterine myometrial cells in the in-labor group showed increased LC3B puncta formation and greater Beclin-1 expression but reduced P62 puncta formation compared with the nonlabor group. The ratio of LC3BII/I proteins was significantly higher, but P62 protein was significantly lower in the in-labor group compared with the nonlabor group. The Beclin-1 mRNA and protein expressions were not significantly different between the 2 groups. CONCLUSION: Autophagy was activated in human uterine myometrium during labor and might play an important role in maintaining uterine contraction function.
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Affiliation(s)
- Lele Wang
- 1 Department of Obstetrics, First Affiliated Hospital of Jinan University, Guangzhou, China
- 2 Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Huiping Hu
- 2 Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Abraham Nick Morse
- 2 Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Xinjia Han
- 2 Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Junjie Bao
- 2 Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Jingying Yang
- 2 Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Yunshan Chen
- 2 Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Huishu Liu
- 2 Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
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19
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Effect of overnight smoking abstinence on a marker for microglial activation: a [ 11C]DAA1106 positron emission tomography study. Psychopharmacology (Berl) 2018; 235:3525-3534. [PMID: 30343364 PMCID: PMC6497451 DOI: 10.1007/s00213-018-5077-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 10/10/2018] [Indexed: 12/27/2022]
Abstract
RATIONALE Microglia are the main immune cells in the central nervous system and participate in neuroinflammation. When activated, microglia express increased levels of the translocator protein 18 kDa (TSPO), thereby making TSPO availability a marker for neuroinflammation. Using positron emission tomography (PET) scanning, our group recently demonstrated that smokers in the satiated state had 16.8% less binding of the radiotracer [11C]DAA1106 (a radioligand for TSPO) in the brain than nonsmokers. OBJECTIVES We sought to determine the effect of overnight smoking abstinence on [11C]DAA1106 binding in the brain. METHODS Forty participants (22 smokers and 18 nonsmokers) completed the study (at one of two sites) and had usable data, which included images from a dynamic [11C]DAA1106 PET scanning session (with smokers having been abstinent for 17.9 ± 2.3 h) and a blood sample for TSPO genotyping. Whole brain standardized uptake values (SUVs) were determined, and analysis of variance was performed, with group (overnight abstinent smoker vs. nonsmoker), site, and TSPO genotype as factors, thereby controlling for site and genotype. RESULTS Overnight abstinent smokers had lower whole brain SUVs (by 15.5 and 17.0% for the two study sites) than nonsmokers (ANCOVA, P = 0.004). The groups did not significantly differ in injected radiotracer dose or body weight, which were used to calculate SUV. CONCLUSIONS These results in overnight abstinent smokers are similar to those in satiated smokers, indicating that chronic cigarette smoking leads to global impairment of microglial activation which persists into early abstinence. Other explanations for study results, such as smoking leading to reduced numbers of microglia or smokers having more rapid metabolism of the radiotracer than nonsmokers, are also possible.
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20
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Linker KE, Cross SJ, Leslie FM. Glial mechanisms underlying substance use disorders. Eur J Neurosci 2018; 50:2574-2589. [PMID: 30240518 DOI: 10.1111/ejn.14163] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 08/23/2018] [Accepted: 08/28/2018] [Indexed: 12/28/2022]
Abstract
Addiction is a devastating disorder that produces persistent maladaptive changes to the central nervous system, including glial cells. Although there is an extensive body of literature examining the neuronal mechanisms of substance use disorders, effective therapies remain elusive. Glia, particularly microglia and astrocytes, have an emerging and meaningful role in a variety of processes beyond inflammation and immune surveillance, and may represent a promising therapeutic target. Indeed, glia actively modulate neurotransmission, synaptic connectivity and neural circuit function, and are critically poised to contribute to addictive-like brain states and behaviors. In this review, we argue that glia influence the cellular, molecular, and synaptic changes that occur in neurons following drug exposure, and that this cellular relationship is critically modified following drug exposure. We discuss direct actions of abused drugs on glial function through immune receptors, such as Toll-like receptor 4, as well as other mechanisms. We highlight how drugs of abuse affect glia-neural communication, and the profound effects that glial-derived factors have on neuronal excitability, structure, and function. Recent research demonstrates that glia have brain region-specific functions, and glia in different brain regions have distinct contributions to drug-associated behaviors. We will also evaluate the evidence demonstrating that glial activation is essential for drug reward and drug-induced dopamine release, and highlight clinical evidence showing that glial mechanisms contribute to drug abuse liability. In this review, we synthesize the extensive evidence that glia have a unique, pivotal, and underappreciated role in the development and maintenance of addiction.
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Affiliation(s)
- K E Linker
- Department of Anatomy and Neurobiology, University of California Irvine, Irvine, CA, USA
| | - S J Cross
- Department of Anatomy and Neurobiology, University of California Irvine, Irvine, CA, USA
| | - F M Leslie
- Department of Pharmacology, University of California Irvine, Irvine, CA, USA
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21
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Changes in the Expression of AQP4 and AQP9 in the Hippocampus Following Eclampsia-Like Seizure. Int J Mol Sci 2018; 19:ijms19010300. [PMID: 29351212 PMCID: PMC5796245 DOI: 10.3390/ijms19010300] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 11/24/2017] [Accepted: 12/04/2017] [Indexed: 01/01/2023] Open
Abstract
Eclampsia is a hypertensive disorder of pregnancy that is defined by the new onset of grand mal seizures on the basis of pre-eclampsia. Until now, the mechanisms underlying eclampsia were poorly understood. Brain edema is considered a leading cause of eclamptic seizures; aquaporins (AQP4 and AQP9), the glial water channel proteins mainly expressed in the nervous system, play an important role in brain edema. We studied AQP4 and AQP9 expression in the hippocampus of pre-eclamptic and eclamptic rats in order to explore the molecular mechanisms involved in brain edema. Using our previous animal models, we found several neuronal deaths in the hippocampal CA1 and CA3 regions after pre-eclampsia and that eclampsia induced more neuronal deaths in both areas by Nissl staining. In the current study, RT-PCR and Western blotting data showed significant upregulation of AQP4 and AQP9 mRNA and protein levels after eclamptic seizures in comparison to pre-eclampsia and at the same time AQP4 and AQP9 immunoreactivity also increased after eclampsia. These findings showed that eclamptic seizures induced cell death and that upregulation of AQP4 and AQP9 may play an important role in this pathophysiological process.
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22
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Li X, Liu H, Yang Y. Magnesium sulfate attenuates brain edema by lowering AQP4 expression and inhibits glia-mediated neuroinflammation in a rodent model of eclampsia. Behav Brain Res 2017; 364:403-412. [PMID: 29288747 DOI: 10.1016/j.bbr.2017.12.031] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 12/23/2017] [Accepted: 12/26/2017] [Indexed: 12/26/2022]
Abstract
Eclampsia is characterized by high morbidity and mortality wordwide. Magnesium sulfate (MgSO4) is used frequently as a prophylaxis for eclamptic seizure in clinical settings. However, the underlying mechanism is less studied, we have previously demonstrated that MgSO4 pretreatment decreases eclampsia-like seizure threshold. Here, we further evaluated the hypothesis that MgSO4 exert neuroprotective actions in eclampsia-like rats model by ameliorating neuroinflammation and brain edema. In this study, the eclampsia-like model was established by administering lipopolysaccharide plus pentylenetetrazol in pregnant Sprague-Dawley rats. Rats were given MgSO4 from gestation day14-19. Then, Iba-1 (a marker for microglia) and S100-B (a marker for astrocytes) expression levels in the hippocampus CA3 region were detected by Enzyme-linked immunosorbent assay. Cerebrospinal fluid (CSF) levels of inflammatory cytokines were measured by Luminex assays. Aquaporin-4 (a transmembrane water channel protein) expression levels in cortex were analyzed using immunohistochemistry. Astrocyte and microglia expressions were detected by immunofluorescence, neuronal damage were evaluated by Nissl staining, and changes in neuronal number in the hippocampal CA3 region (CA3) among different groups were detected by neuronal nuclei staining. Our results demonstrated that MgSO4 effectively attenuated astrocyte and microglia activation and promoted the neuronal survival in the CA3. Additionally, MgSO4 significantly reduced inflammatory cytokines response in the CSF, and decreased the expression of AQP-4 protein in the cortex. Collectively, the findings of this study indicated that MgSO4 has a neuroprotective role in eclampsia-like seizure rats through its anti-neuroninflammatory and brain edema-attenuating properties.
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Affiliation(s)
- Xiaolan Li
- Department of Obstetrics and Gynaecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China; Department of Obstetrics, Guangzhou Women and Children's Medical Center, China; Anhui Province Key Laboratory of Reproductive Health and Genetics, Anhui Medical University, Hefei, China
| | - Huishu Liu
- Department of Obstetrics, Guangzhou Women and Children's Medical Center, China
| | - Yuanyuan Yang
- Department of Obstetrics and Gynaecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China; Anhui Province Key Laboratory of Reproductive Health and Genetics, Anhui Medical University, Hefei, China.
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23
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Chi B, Wang S, Bi S, Qin W, Wu D, Luo Z, Gui S, Wang D, Yin X, Wang F. Effects of ganoderic acid A on lipopolysaccharide-induced proinflammatory cytokine release from primary mouse microglia cultures. Exp Ther Med 2017; 15:847-853. [PMID: 29399089 PMCID: PMC5772755 DOI: 10.3892/etm.2017.5472] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 08/24/2017] [Indexed: 01/13/2023] Open
Abstract
For several thousand years, Ganoderma lucidum (Ling-Zhi in Chinese and Reishi in Japanese) has been widely used as a traditional medication for the prevention and treatment of various diseases in Asia. Its major biologically active components, ganoderic acids (GAs), exhibit significant medicinal value due to their anti-inflammatory effects. Dysregulation of microglial function may cause seizures or promote epileptogenesis through release of proinflammatory cytokines, including interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α. At present, only little information is available on the effects of GAs on microglia-mediated inflammation in vitro and/or in vivo. The present study aimed to investigate the role of GA-A on microglia-mediated inflammation in vitro. In addition, the effect of GA-A on lipopolysaccharide (LPS)-evoked alterations in mitochondrial metabolic activity of microglia was evaluated. The results of the present study demonstrated that GA-A significantly decreased LPS-induced IL-1β, IL-6 and TNF-α release from mouse-derived primary cortical microglial cells in a concentration-dependent manner. GA-A treatment reduced LPS-induced expression of nuclear factor (NF)-κB (p65) and its inhibitor, demonstrating that non-toxic suppression of IL-1β, IL-6 and TNF-α production by GA-A is, at least in part, due to suppression of the NF-κB signaling pathway. In addition, the LPS-induced stimulation of mitochondrial activity of microglial cells was abolished by co-treatment with GA-A. Thus, GA-A treatment may be a potential therapeutic strategy for epilepsy prevention by suppressing microglia-derived proinflammatory mediators.
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Affiliation(s)
- Baojin Chi
- Basic Medical College, Jiamusi University, Jiamusi, Heilongjiang 154007, P.R. China.,Department of Urology, The First Affiliated Hospital of Jiamusi University, Jiamusi, Heilongjiang 154003, P.R. China
| | - Shuqiu Wang
- Basic Medical College, Jiamusi University, Jiamusi, Heilongjiang 154007, P.R. China
| | - Sheng Bi
- Department of Urology, The First Affiliated Hospital of Jiamusi University, Jiamusi, Heilongjiang 154003, P.R. China
| | - Wenbo Qin
- Department of Urology, The Second Affiliated Hospital of Jiamusi University, Jiamusi, Heilongjiang 154002, P.R. China
| | - Dongmei Wu
- Material College, Jiamusi University, Jiamusi, Heilongjiang 154007, P.R. China
| | - Zhenguo Luo
- Department of Urology, The First Affiliated Hospital of Jiamusi University, Jiamusi, Heilongjiang 154003, P.R. China
| | - Shiliang Gui
- Department of Urology, The First Affiliated Hospital of Jiamusi University, Jiamusi, Heilongjiang 154003, P.R. China
| | - Dongwei Wang
- Department of Urology, The First Affiliated Hospital of Jiamusi University, Jiamusi, Heilongjiang 154003, P.R. China
| | - Xingzhong Yin
- Basic Medical College, Jiamusi University, Jiamusi, Heilongjiang 154007, P.R. China
| | - Fangfang Wang
- Basic Medical College, Jiamusi University, Jiamusi, Heilongjiang 154007, P.R. China
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24
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Zhang M, Han X, Bao J, Yang J, Shi SQ, Garfield RE, Liu H. Choline Supplementation During Pregnancy Protects Against Gestational Lipopolysaccharide-Induced Inflammatory Responses. Reprod Sci 2017; 25:74-85. [PMID: 28436303 DOI: 10.1177/1933719117702247] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
OBJECTIVES To estimate the effects and mechanisms of choline, an essential nutrient and a selective α7 nicotinic acetylcholine receptor (α7nAChR) agonist, on the prevention of symptoms and the effects on the cholinergic anti-inflammatory pathways (CAP) in a lipopolysaccharide (LPS)-induced inflammatory response in a rat model. METHODS Inflammation was induced by LPS treatment (1.0 μg LPS/kg body weight) on gestational day (GD) 14. Nonpregnant and pregnant Sprague Dawley rats were placed on a normal choline diet (1.1 g/kg) or supplemented choline diet (5.0 g/kg) from GDs 1 to 20. Systolic blood pressure (SBP), urinary albumin, and pregnancy outcomes were recorded. On GD 20, serum and placentas were assayed for cytokines. Western blots were used to determine the expression of placenta α7nAChR and components of the α7nAChR-CAP, including nuclear factor-κB (NF-κB) and protein kinase B (AKT). Immunohistochemistry was used to localize placental sites for the p65 subunit of NF-κB. RESULTS Lipopolysaccharide significantly increased SBP and urinary albumin and decreased pregnancy outcomes, and these effects were partially reversed by higher choline treatment. Choline supplementation also significantly attenuated the LPS-induced increase in serum and placental inflammatory cytokines, decreased the expression of placental α7nAChR, lowered the activation of NF-κB signaling in placenta mononuclear cells, and inhibited placental AKT phosphorylation. CONCLUSION This study confirms that LPS induces inflammatory conditions in pregnant rats and shows that choline supplementation protects against the inflammatory symptoms through its action on α7nAChR and CAP. These observations have important implications for the prevention and treatment of inflammatory responses associated with pregnancy.
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Affiliation(s)
- Min Zhang
- 1 Department of Obstetrics, Preterm Birth Prevention and Treatment Research Unit, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Xinjia Han
- 1 Department of Obstetrics, Preterm Birth Prevention and Treatment Research Unit, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Juejie Bao
- 1 Department of Obstetrics, Preterm Birth Prevention and Treatment Research Unit, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Jinying Yang
- 1 Department of Obstetrics, Preterm Birth Prevention and Treatment Research Unit, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Shao-Qing Shi
- 1 Department of Obstetrics, Preterm Birth Prevention and Treatment Research Unit, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Robert E Garfield
- 1 Department of Obstetrics, Preterm Birth Prevention and Treatment Research Unit, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Huishu Liu
- 1 Department of Obstetrics, Preterm Birth Prevention and Treatment Research Unit, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
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25
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Frasch MG, Szynkaruk M, Prout AP, Nygard K, Cao M, Veldhuizen R, Hammond R, Richardson BS. Decreased neuroinflammation correlates to higher vagus nerve activity fluctuations in near-term ovine fetuses: a case for the afferent cholinergic anti-inflammatory pathway? J Neuroinflammation 2016; 13:103. [PMID: 27165310 PMCID: PMC4894374 DOI: 10.1186/s12974-016-0567-x] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 05/02/2016] [Indexed: 12/18/2022] Open
Abstract
Background Neuroinflammation in utero may contribute to brain injury resulting in life-long neurological disabilities. The pivotal role of the efferent cholinergic anti-inflammatory pathway (CAP) in controlling inflammation, e.g., by inhibiting the HMGB1 release, via the macrophages’ α7 nicotinic acetylcholine receptor (α7nAChR) has been described in adults, but its importance in the fetus is unknown. Moreover, it is unknown whether CAP may also exert anti-inflammatory effects on the brain via the anatomically predominant afferent component of the vagus nerve. Methods We measured microglial activation in the ovine fetal brain near term 24 h after the umbilical cord occlusions mimicking human labor versus controls (no occlusions) by quantifying HMGB1 nucleus-to-cytosol translocation in the Iba1+ and α7nAChR+ microglia. Based on multiple clinical studies in adults and our own work in fetal autonomic nervous system, we gauged the degree of CAP activity in vivo using heart rate variability measure RMSSD that reflects fluctuations in vagus nerve activity. Results RMSSD correlated to corresponding plasma IL-1β levels at R = 0.57 (p = 0.02, n = 17) and to white matter microglia cell counts at R = −0.89 (p = 0.03). The insult increased the HMGB1 translocation in α7nAChR+ microglia in a brain region-dependent manner (p < 0.001). In parallel, RMSSD at 1 h post insult correlated with cytosolic HMGB1 of thalamic microglia (R = −0.94, p = 0.005), and RMSSD at pH nadir correlated with microglial α7nAChR in the white matter (R = 0.83, p = 0.04). Overall, higher RMSSD values correlated with lower HMGB1 translocation and higher α7nAChR intensity per area in a brain region-specific manner. Conclusions Afferent fetal CAP may translate increased vagal cholinergic signaling into suppression of cerebral inflammation in response to near-term hypoxic acidemia as might occur during labor. Our findings suggest a new control mechanism of fetal neuroinflammation via the vagus nerve, providing novel possibilities for its non-invasive monitoring in utero and for targeted treatment. Electronic supplementary material The online version of this article (doi:10.1186/s12974-016-0567-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- M G Frasch
- Department of Obstetrics and Gynaecology, CHU Ste-Justine Research Centre, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada. .,Department of Neurosciences, CHU Ste-Justine Research Centre, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada. .,Animal Reproduction Research Centre (CRRA), Faculty of Veterinary Medicine, Université de Montréal, Montréal, QC, Canada. .,Department of Obstetrics and Gynaecology, Lawson Health Research Institute, University of Western Ontario, London, ON, Canada. .,Department of Obstetrics and Gynecology, University of Washington, 1959 NE Pacific St, Box 356460, Seattle, WA, 98195, USA.
| | - M Szynkaruk
- Department of Obstetrics and Gynaecology, Lawson Health Research Institute, University of Western Ontario, London, ON, Canada
| | - A P Prout
- Department of Obstetrics and Gynaecology, Lawson Health Research Institute, University of Western Ontario, London, ON, Canada
| | - K Nygard
- Microscopy Imaging@Biotron, University of Western Ontario, London, ON, Canada
| | - M Cao
- Department of Obstetrics and Gynaecology, CHU Ste-Justine Research Centre, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada.,Department of Neurosciences, CHU Ste-Justine Research Centre, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada
| | - R Veldhuizen
- Department of Physiology and Pharmacology, University of Western Ontario, London, ON, Canada
| | - R Hammond
- Department of Pathology, University of Western Ontario, London, ON, Canada
| | - B S Richardson
- Department of Obstetrics and Gynaecology, Lawson Health Research Institute, University of Western Ontario, London, ON, Canada.,Department of Physiology and Pharmacology, University of Western Ontario, London, ON, Canada
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