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Leavy A, Phelan J, Jimenez-Mateos EM. Contribution of microglia to the epileptiform activity that results from neonatal hypoxia. Neuropharmacology 2024; 253:109968. [PMID: 38692453 DOI: 10.1016/j.neuropharm.2024.109968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 04/13/2024] [Accepted: 04/22/2024] [Indexed: 05/03/2024]
Abstract
Microglia are described as the immune cells of the brain, their immune properties have been extensively studied since first described, however, their neural functions have only been explored over the last decade. Microglia have an important role in maintaining homeostasis in the central nervous system by surveying their surroundings to detect pathogens or damage cells. While these are the classical functions described for microglia, more recently their neural functions have been defined; they are critical to the maturation of neurons during embryonic and postnatal development, phagocytic microglia remove excess synapses during development, a process called synaptic pruning, which is important to overall neural maturation. Furthermore, microglia can respond to neuronal activity and, together with astrocytes, can regulate neural activity, contributing to the equilibrium between excitation and inhibition through a feedback loop. Hypoxia at birth is a serious neurological condition that disrupts normal brain function resulting in seizures and epilepsy later in life. Evidence has shown that microglia may contribute to this hyperexcitability after neonatal hypoxia. This review will summarize the existing data on the role of microglia in the pathogenesis of neonatal hypoxia and the plausible mechanisms that contribute to the development of hyperexcitability after hypoxia in neonates. This article is part of the Special Issue on "Microglia".
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Affiliation(s)
- Aisling Leavy
- Discipline of Physiology, School of Medicine, Trinity College Dublin, The University of Dublin, Dublin, Ireland
| | - Jessie Phelan
- Discipline of Physiology, School of Medicine, Trinity College Dublin, The University of Dublin, Dublin, Ireland
| | - Eva M Jimenez-Mateos
- Discipline of Physiology, School of Medicine, Trinity College Dublin, The University of Dublin, Dublin, Ireland.
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Li X, Liu N, Wu D, Li SC, Wang Q, Zhang DW, Song LL, Huang M, Chen X, Li W. Hippocampal transcriptomic analyses reveal the potential antiapoptotic mechanism of a novel anticonvulsant agent Q808 on pentylenetetrazol-induced epilepsy in rats. Biomed Pharmacother 2024; 175:116746. [PMID: 38739991 DOI: 10.1016/j.biopha.2024.116746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 05/08/2024] [Accepted: 05/09/2024] [Indexed: 05/16/2024] Open
Abstract
Brain apoptosis is one of the main causes of epileptogenesis. The antiapoptotic effect and potential mechanism of Q808, an innovative anticonvulsant chemical, have never been reported. In this study, the seizure stage and latency to reach stage 2 of pentylenetetrazol (PTZ) seizure rat model treated with Q808 were investigated. The morphological change and neuronal apoptosis in the hippocampus were detected by hematoxylin and eosin (HE) and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) staining, respectively. The hippocampal transcriptomic changes were observed using RNA sequencing (RNA-seq). The expression levels of hub genes were verified by quantitative reverse-transcription PCR (qRT-PCR). Results revealed that Q808 could allay the seizure score and prolong the stage 2 latency in seizure rats. The morphological changes of neurons and the number of apoptotic cells in the DG area were diminished by Q808 treatment. RNA-seq analysis revealed eight hub genes, including Map2k3, Nfs1, Chchd4, Hdac6, Siglec5, Slc35d3, Entpd1, and LOC103690108, and nine hub pathways among the control, PTZ, and Q808 groups. Hub gene Nfs1 was involved in the hub pathway sulfur relay system, and Map2k3 was involved in the eight remaining hub pathways, including Amyotrophic lateral sclerosis, Cellular senescence, Fc epsilon RI signaling pathway, GnRH signaling pathway, Influenza A, Rap1 signaling pathway, TNF signaling pathway, and Toll-like receptor signaling pathway. qRT-PCR confirmed that the mRNA levels of these hub genes were consistent with the RNA-seq results. Our findings might contribute to further studies exploring the new apoptosis mechanism and actions of Q808.
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Affiliation(s)
- Xiang Li
- Department of Pharmacology, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, China
| | - Ning Liu
- Jilin Academy of Chinese Medicine Sciences, Changchun, Jilin 130015, China
| | - Di Wu
- Jilin Academy of Chinese Medicine Sciences, Changchun, Jilin 130015, China
| | - Shu Chang Li
- Jilin Cancer Hospital, ChangChun, Jilin 130012, China
| | - Qing Wang
- Jilin Academy of Chinese Medicine Sciences, Changchun, Jilin 130015, China
| | - Dian-Wen Zhang
- Jilin Academy of Chinese Medicine Sciences, Changchun, Jilin 130015, China
| | - Lian-Lian Song
- Jilin Academy of Chinese Medicine Sciences, Changchun, Jilin 130015, China
| | - Min Huang
- Department of Pharmacology, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, China
| | - Xia Chen
- Department of Pharmacology, College of Basic Medical Sciences, Jilin University, Changchun, Jilin 130021, China.
| | - Wei Li
- Jilin Academy of Chinese Medicine Sciences, Changchun, Jilin 130015, China.
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Guan X, Zhu S, Song J, Liu K, Liu M, Xie L, Wang Y, Wu J, Xu X, Pang T. Microglial CMPK2 promotes neuroinflammation and brain injury after ischemic stroke. Cell Rep Med 2024; 5:101522. [PMID: 38701781 PMCID: PMC11148565 DOI: 10.1016/j.xcrm.2024.101522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Revised: 02/08/2024] [Accepted: 03/28/2024] [Indexed: 05/05/2024]
Abstract
Neuroinflammation plays a significant role in ischemic injury, which can be promoted by oxidized mitochondrial DNA (Ox-mtDNA). Cytidine/uridine monophosphate kinase 2 (CMPK2) regulates mtDNA replication, but its role in neuroinflammation and ischemic injury remains unknown. Here, we report that CMPK2 expression is upregulated in monocytes/macrophages and microglia post-stroke in humans and mice, respectively. Microglia/macrophage CMPK2 knockdown using the Cre recombination-dependent adeno-associated virus suppresses the inflammatory responses in the brain, reduces infarcts, and improves neurological outcomes in ischemic CX3CR1Cre/ERT2 mice. Mechanistically, CMPK2 knockdown limits newly synthesized mtDNA and Ox-mtDNA formation and subsequently blocks NLRP3 inflammasome activation in microglia/macrophages. Nordihydroguaiaretic acid (NDGA), as a CMPK2 inhibitor, is discovered to reduce neuroinflammation and ischemic injury in mice and prevent the inflammatory responses in primary human monocytes from ischemic patients. Thus, these findings identify CMPK2 as a promising therapeutic target for ischemic stroke and other brain disorders associated with neuroinflammation.
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Affiliation(s)
- Xin Guan
- State Key Laboratory of Natural Medicines, New Drug Screening Center, Key Laboratory of Drug Quality Control and Pharmacovigilance (Ministry of Education), China Pharmaceutical University, Nanjing 210009, P.R. China
| | - Sitong Zhu
- State Key Laboratory of Natural Medicines, New Drug Screening Center, Key Laboratory of Drug Quality Control and Pharmacovigilance (Ministry of Education), China Pharmaceutical University, Nanjing 210009, P.R. China
| | - Jinqian Song
- State Key Laboratory of Natural Medicines, New Drug Screening Center, Key Laboratory of Drug Quality Control and Pharmacovigilance (Ministry of Education), China Pharmaceutical University, Nanjing 210009, P.R. China
| | - Kui Liu
- State Key Laboratory of Natural Medicines, New Drug Screening Center, Key Laboratory of Drug Quality Control and Pharmacovigilance (Ministry of Education), China Pharmaceutical University, Nanjing 210009, P.R. China
| | - Mei Liu
- Department of Neurology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing 210011, P.R. China
| | - Luyang Xie
- State Key Laboratory of Natural Medicines, New Drug Screening Center, Key Laboratory of Drug Quality Control and Pharmacovigilance (Ministry of Education), China Pharmaceutical University, Nanjing 210009, P.R. China
| | - Yifang Wang
- Department of Neurology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing 210011, P.R. China
| | - Jin Wu
- Department of Neurology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing 210011, P.R. China.
| | - Xiaojun Xu
- Department of Pharmacy, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Center for Innovative Traditional Chinese Medicine Target and New Drug Research, International Institutes of Medicine, Zhejiang University, Yiwu, Zhejiang Province 322000, P.R. China.
| | - Tao Pang
- State Key Laboratory of Natural Medicines, New Drug Screening Center, Key Laboratory of Drug Quality Control and Pharmacovigilance (Ministry of Education), China Pharmaceutical University, Nanjing 210009, P.R. China; State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing 210023, P.R. China.
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Ravizza T, Scheper M, Di Sapia R, Gorter J, Aronica E, Vezzani A. mTOR and neuroinflammation in epilepsy: implications for disease progression and treatment. Nat Rev Neurosci 2024; 25:334-350. [PMID: 38531962 DOI: 10.1038/s41583-024-00805-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/27/2024] [Indexed: 03/28/2024]
Abstract
Epilepsy remains a major health concern as anti-seizure medications frequently fail, and there is currently no treatment to stop or prevent epileptogenesis, the process underlying the onset and progression of epilepsy. The identification of the pathological processes underlying epileptogenesis is instrumental to the development of drugs that may prevent the generation of seizures or control pharmaco-resistant seizures, which affect about 30% of patients. mTOR signalling and neuroinflammation have been recognized as critical pathways that are activated in brain cells in epilepsy. They represent a potential node of biological convergence in structural epilepsies with either a genetic or an acquired aetiology. Interventional studies in animal models and clinical studies give strong support to the involvement of each pathway in epilepsy. In this Review, we focus on available knowledge about the pathophysiological features of mTOR signalling and the neuroinflammatory brain response, and their interactions, in epilepsy. We discuss mitigation strategies for each pathway that display therapeutic effects in experimental and clinical epilepsy. A deeper understanding of these interconnected molecular cascades could enhance our strategies for managing epilepsy. This could pave the way for new treatments to fill the gaps in the development of preventative or disease-modifying drugs, thus overcoming the limitations of current symptomatic medications.
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Affiliation(s)
- Teresa Ravizza
- Department of Acute Brain and Cardiovascular Injury, Mario Negri Institute for Pharmacological Research IRCCS, Milano, Italy
| | - Mirte Scheper
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Rossella Di Sapia
- Department of Acute Brain and Cardiovascular Injury, Mario Negri Institute for Pharmacological Research IRCCS, Milano, Italy
| | - Jan Gorter
- Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Amsterdam, The Netherlands
| | - Eleonora Aronica
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.
- Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, The Netherlands.
| | - Annamaria Vezzani
- Department of Acute Brain and Cardiovascular Injury, Mario Negri Institute for Pharmacological Research IRCCS, Milano, Italy.
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Kim W, Kim M, Kim B. Unraveling the enigma: housekeeping gene Ugt1a7c as a universal biomarker for microglia. Front Psychiatry 2024; 15:1364201. [PMID: 38666091 PMCID: PMC11043603 DOI: 10.3389/fpsyt.2024.1364201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/01/2024] [Accepted: 03/26/2024] [Indexed: 04/28/2024] Open
Abstract
Background Microglia, brain resident macrophages, play multiple roles in maintaining homeostasis, including immunity, surveillance, and protecting the central nervous system through their distinct activation processes. Identifying all types of microglia-driven populations is crucial due to the presence of various phenotypes that differ based on developmental stages or activation states. During embryonic development, the E8.5 yolk sac contains erythromyeloid progenitors that go through different growth phases, eventually resulting in the formation of microglia. In addition, microglia are present in neurological diseases as a diverse population. So far, no individual biomarker for microglia has been discovered that can accurately identify and monitor their development and attributes. Summary Here, we highlight the newly defined biomarker of mouse microglia, UGT1A7C, which exhibits superior stability in expression during microglia development and activation compared to other known microglia biomarkers. The UGT1A7C sensing chemical probe labels all microglia in the 3xTG AD mouse model. The expression of Ugt1a7c is stable during development, with only a 4-fold variation, while other microglia biomarkers, such as Csf1r and Cx3cr1, exhibit at least a 10-fold difference. The UGT1A7C expression remains constant throughout its lifespan. In addition, the expression and activity of UGT1A7C are the same in response to different types of inflammatory activators' treatment in vitro. Conclusion We propose employing UGT1A7C as the representative biomarker for microglia, irrespective of their developmental state, age, or activation status. Using UGT1A7C can reduce the requirement for using multiple biomarkers, enhance the precision of microglia analysis, and even be utilized as a standard for gene/protein expression.
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Affiliation(s)
| | | | - Beomsue Kim
- Neural Circuit Research Group, Korea Brain Research Institute, Daegu, Republic of Korea
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Del Pozo A, Knox KM, Lehmann LM, Davidson S, Rho SL, Jayadev S, Barker-Haliski M. Chronic evoked seizures in young pre-symptomatic APP/PS1 mice induce serotonin changes and accelerate onset of Alzheimer's disease-related neuropathology. Prog Neurobiol 2024; 235:102591. [PMID: 38484965 PMCID: PMC11015961 DOI: 10.1016/j.pneurobio.2024.102591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 02/29/2024] [Accepted: 03/05/2024] [Indexed: 03/18/2024]
Abstract
OBJECTIVE Hyperexcitability is intimately linked to Alzheimer's disease (AD) pathology, but the precise timing and contributions of neuronal hyperexcitability to disease progression is unclear. Seizure induction in rodent AD models can uncover new therapeutic targets. Further, investigator-evoked seizures can directly establish how hyperexcitability and AD-associated risk factors influence neuropathological hallmarks and disease course at presymptomatic stages. METHODS Corneal kindling is a well-characterized preclinical epilepsy model that allows for precise control of seizure history to pair to subsequent behavioral assessments. 2-3-month-old APP/PS1, PSEN2-N141I, and transgenic control male and female mice were thus sham or corneal kindled for 2 weeks. Seizure-induced changes in glia, serotonin pathway proteins, and amyloid β levels in hippocampus and prefrontal cortex were quantified. RESULTS APP/PS1 females were more susceptible to corneal kindling. However, regardless of sex, APP/PS1 mice experienced extensive seizure-induced mortality versus kindled Tg- controls. PSEN2-N141I mice were not negatively affected by corneal kindling. Mortality correlated with a marked downregulation of hippocampal tryptophan hydroxylase 2 and monoamine oxidase A protein expression versus controls; these changes were not detected in PSEN2-N141I mice. Kindled APP/PS1 mice also exhibited soluble amyloid β upregulation and glial reactivity without plaque deposition. SIGNIFICANCE Evoked convulsive seizures and neuronal hyperexcitability in pre-symptomatic APP/PS1 mice promoted premature mortality without pathological Aβ plaque deposition, whereas PSEN2-N141I mice were unaffected. Disruptions in serotonin pathway metabolism in APP/PS1 mice was associated with increased glial reactivity without Aβ plaque deposition, demonstrating that neuronal hyperexcitability in early AD causes pathological Aβ overexpression and worsens long-term outcomes through a serotonin-related mechanism.
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Affiliation(s)
- Aaron Del Pozo
- Center for Epilepsy Drug Discovery (CEDD), Department of Pharmacy, University of Washington, Seattle, WA 98195, USA
| | - Kevin M Knox
- Center for Epilepsy Drug Discovery (CEDD), Department of Pharmacy, University of Washington, Seattle, WA 98195, USA
| | - Leanne M Lehmann
- Center for Epilepsy Drug Discovery (CEDD), Department of Pharmacy, University of Washington, Seattle, WA 98195, USA
| | - Stephanie Davidson
- Center for Epilepsy Drug Discovery (CEDD), Department of Pharmacy, University of Washington, Seattle, WA 98195, USA
| | - Seongheon Leo Rho
- Center for Epilepsy Drug Discovery (CEDD), Department of Pharmacy, University of Washington, Seattle, WA 98195, USA
| | - Suman Jayadev
- Department of Neurology, University of Washington, Seattle, WA 98195, USA
| | - Melissa Barker-Haliski
- Center for Epilepsy Drug Discovery (CEDD), Department of Pharmacy, University of Washington, Seattle, WA 98195, USA.
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Luo Y, Wang Z. The Impact of Microglia on Neurodevelopment and Brain Function in Autism. Biomedicines 2024; 12:210. [PMID: 38255315 PMCID: PMC10813633 DOI: 10.3390/biomedicines12010210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 12/29/2023] [Accepted: 01/09/2024] [Indexed: 01/24/2024] Open
Abstract
Microglia, as one of the main types of glial cells in the central nervous system (CNS), are widely distributed throughout the brain and spinal cord. The normal number and function of microglia are very important for maintaining homeostasis in the CNS. In recent years, scientists have paid widespread attention to the role of microglia in the CNS. Autism spectrum disorder (ASD) is a highly heterogeneous neurodevelopmental disorder, and patients with ASD have severe deficits in behavior, social skills, and communication. Most previous studies on ASD have focused on neuronal pathological changes, such as increased cell proliferation, accelerated neuronal differentiation, impaired synaptic development, and reduced neuronal spontaneous and synchronous activity. Currently, more and more research has found that microglia, as immune cells, can promote neurogenesis and synaptic pruning to maintain CNS homeostasis. They can usually reduce unnecessary synaptic connections early in life. Some researchers have proposed that many pathological phenotypes of ASD may be caused by microglial abnormalities. Based on this, we summarize recent research on microglia in ASD, focusing on the function of microglia and neurodevelopmental abnormalities. We aim to clarify the essential factors influenced by microglia in ASD and explore the possibility of microglia-related pathways as potential research targets for ASD.
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Affiliation(s)
- Yuyi Luo
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming 650500, China;
- Yunnan Key Laboratory of Primate Biomedical Research, Kunming 650500, China
| | - Zhengbo Wang
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming 650500, China;
- Yunnan Key Laboratory of Primate Biomedical Research, Kunming 650500, China
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Dang Y, Wang T. Research Progress on the Immune-Inflammatory Mechanisms of Posttraumatic Epilepsy. Cell Mol Neurobiol 2023; 43:4059-4069. [PMID: 37889439 DOI: 10.1007/s10571-023-01429-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 10/17/2023] [Indexed: 10/28/2023]
Abstract
Posttraumatic epilepsy (PTE) is a severe complication arising from a traumatic brain injury caused by various violent actions on the brain. The underlying mechanisms for the pathogenesis of PTE are complex and have not been fully defined. Approximately, one-third of patients with PTE are resistant to antiepileptic therapy. Recent research evidence has shown that neuroinflammation is critical in the development of PTE. This article reviews the immune-inflammatory mechanisms regarding microglial activation, astrocyte proliferation, inflammatory signaling pathways, chronic neuroinflammation, and intestinal flora. These mechanisms offer novel insights into the pathophysiological mechanisms of PTE and have groundbreaking implications in the prevention and treatment of PTE. Immunoinflammatory cross-talk between glial cells and gut microbiota in posttraumatic epilepsy. This graphical abstract depicts the roles of microglia and astrocytes in posttraumatic epilepsy, highlighting the influence of the gut microbiota on their function. TBI traumatic brain injury, AQP4 aquaporin-4, Kir4.1 inward rectifying K channels.
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Affiliation(s)
- Yangbin Dang
- Department of Neurology, Epilepsy Center, Lanzhou University Second Hospital, No. 82 Cuiyingmen, Lanzhou, 730000, Gansu, China
| | - Tiancheng Wang
- Department of Neurology, Epilepsy Center, Lanzhou University Second Hospital, No. 82 Cuiyingmen, Lanzhou, 730000, Gansu, China.
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