1
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Pramanik S, Devi M H, Chakrabarty S, Paylar B, Pradhan A, Thaker M, Ayyadhury S, Manavalan A, Olsson PE, Pramanik G, Heese K. Microglia signaling in health and disease - Implications in sex-specific brain development and plasticity. Neurosci Biobehav Rev 2024; 165:105834. [PMID: 39084583 DOI: 10.1016/j.neubiorev.2024.105834] [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: 05/05/2024] [Revised: 07/21/2024] [Accepted: 07/27/2024] [Indexed: 08/02/2024]
Abstract
Microglia, the intrinsic neuroimmune cells residing in the central nervous system (CNS), exert a pivotal influence on brain development, homeostasis, and functionality, encompassing critical roles during both aging and pathological states. Recent advancements in comprehending brain plasticity and functions have spotlighted conspicuous variances between male and female brains, notably in neurogenesis, neuronal myelination, axon fasciculation, and synaptogenesis. Nevertheless, the precise impact of microglia on sex-specific brain cell plasticity, sculpting diverse neural network architectures and circuits, remains largely unexplored. This article seeks to unravel the present understanding of microglial involvement in brain development, plasticity, and function, with a specific emphasis on microglial signaling in brain sex polymorphism. Commencing with an overview of microglia in the CNS and their associated signaling cascades, we subsequently probe recent revelations regarding molecular signaling by microglia in sex-dependent brain developmental plasticity, functions, and diseases. Notably, C-X3-C motif chemokine receptor 1 (CX3CR1), triggering receptors expressed on myeloid cells 2 (TREM2), calcium (Ca2+), and apolipoprotein E (APOE) emerge as molecular candidates significantly contributing to sex-dependent brain development and plasticity. In conclusion, we address burgeoning inquiries surrounding microglia's pivotal role in the functional diversity of developing and aging brains, contemplating their potential implications for gender-tailored therapeutic strategies in neurodegenerative diseases.
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Affiliation(s)
- Subrata Pramanik
- Jyoti and Bhupat Mehta School of Health Sciences and Technology, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India.
| | - Harini Devi M
- Jyoti and Bhupat Mehta School of Health Sciences and Technology, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - Saswata Chakrabarty
- Jyoti and Bhupat Mehta School of Health Sciences and Technology, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - Berkay Paylar
- Biology, The Life Science Center, School of Science and Technology, Örebro University, Örebro 70182, Sweden
| | - Ajay Pradhan
- Biology, The Life Science Center, School of Science and Technology, Örebro University, Örebro 70182, Sweden
| | - Manisha Thaker
- Eurofins Lancaster Laboratories, Inc., 2425 New Holland Pike, Lancaster, PA 17601, USA
| | - Shamini Ayyadhury
- The Donnelly Centre, University of Toronto, Toronto, Ontario M5S 3E1, Canada
| | - Arulmani Manavalan
- Department of Cariology, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Chennai, Tamil Nadu 600077, India
| | - Per-Erik Olsson
- Biology, The Life Science Center, School of Science and Technology, Örebro University, Örebro 70182, Sweden
| | - Gopal Pramanik
- Department of Pharmaceutical Sciences and Technology, Birla Institute of Technology, Mesra, Ranchi, Jharkhand 835215, India.
| | - Klaus Heese
- Graduate School of Biomedical Science and Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 133791, the Republic of Korea.
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2
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Kolahchi Z, Henkel N, Eladawi MA, Villarreal EC, Kandimalla P, Lundh A, McCullumsmith RE, Cuevas E. Sex and Gender Differences in Alzheimer's Disease: Genetic, Hormonal, and Inflammation Impacts. Int J Mol Sci 2024; 25:8485. [PMID: 39126053 PMCID: PMC11313277 DOI: 10.3390/ijms25158485] [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: 04/16/2024] [Revised: 07/26/2024] [Accepted: 07/28/2024] [Indexed: 08/12/2024] Open
Abstract
Two-thirds of Americans with Alzheimer's disease are women, indicating a profound variance between the sexes. Variances exist between the sexes in the age and intensity of the presentation, cognitive deficits, neuroinflammatory factors, structural and functional brain changes, as well as psychosocial and cultural circumstances. Herein, we summarize the existing evidence for sexual dimorphism and present the available evidence for these distinctions. Understanding these complexities is critical to developing personalized interventions for the prevention, care, and treatment of Alzheimer's disease.
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Affiliation(s)
- Zahra Kolahchi
- Department of Neurology, Mitchell Center for Neurodegenerative Diseases, School of Medicine, University of Texas Medical Branch, Galveston, TX 77555, USA; (Z.K.); (E.C.V.)
| | - Nicholas Henkel
- Department of Neurosciences and Neurological Disorders, College of Medicine and Life Sciences, The University of Toledo, Toledo, OH 43614, USA; (N.H.); (M.A.E.); (P.K.); (A.L.); (R.E.M.)
| | - Mahmoud A. Eladawi
- Department of Neurosciences and Neurological Disorders, College of Medicine and Life Sciences, The University of Toledo, Toledo, OH 43614, USA; (N.H.); (M.A.E.); (P.K.); (A.L.); (R.E.M.)
| | - Emma C. Villarreal
- Department of Neurology, Mitchell Center for Neurodegenerative Diseases, School of Medicine, University of Texas Medical Branch, Galveston, TX 77555, USA; (Z.K.); (E.C.V.)
| | - Prathik Kandimalla
- Department of Neurosciences and Neurological Disorders, College of Medicine and Life Sciences, The University of Toledo, Toledo, OH 43614, USA; (N.H.); (M.A.E.); (P.K.); (A.L.); (R.E.M.)
| | - Anna Lundh
- Department of Neurosciences and Neurological Disorders, College of Medicine and Life Sciences, The University of Toledo, Toledo, OH 43614, USA; (N.H.); (M.A.E.); (P.K.); (A.L.); (R.E.M.)
| | - Robert E. McCullumsmith
- Department of Neurosciences and Neurological Disorders, College of Medicine and Life Sciences, The University of Toledo, Toledo, OH 43614, USA; (N.H.); (M.A.E.); (P.K.); (A.L.); (R.E.M.)
- ProMedica Neurosciences Center, Toledo, OH 43606, USA
| | - Elvis Cuevas
- Department of Neurology, Mitchell Center for Neurodegenerative Diseases, School of Medicine, University of Texas Medical Branch, Galveston, TX 77555, USA; (Z.K.); (E.C.V.)
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3
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Shebindu A, Kaveti D, Umutoni L, Kirk G, Burton MD, Jones CN. A programmable microfluidic platform to monitor calcium dynamics in microglia during inflammation. MICROSYSTEMS & NANOENGINEERING 2024; 10:106. [PMID: 39101003 PMCID: PMC11294448 DOI: 10.1038/s41378-024-00733-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 04/01/2024] [Accepted: 05/22/2024] [Indexed: 08/06/2024]
Abstract
Neuroinflammation is characterized by the elevation of cytokines and adenosine triphosphate (ATP), which in turn activates microglia. These immunoregulatory molecules typically form gradients in vivo, which significantly influence microglial behaviors such as increasing calcium signaling, migration, phagocytosis, and cytokine secretion. Quantifying microglial calcium signaling in the context of inflammation holds the potential for developing precise therapeutic strategies for neurological diseases. However, the current calcium imaging systems are technically challenging to operate, necessitate large volumes of expensive reagents and cells, and model immunoregulatory molecules as uniform concentrations, failing to accurately replicate the in vivo microenvironment. In this study, we introduce a novel calcium monitoring micro-total analysis system (CAM-μTAS) designed to quantify calcium dynamics in microglia (BV2 cells) within defined cytokine gradients. Leveraging programmable pneumatically actuated lifting gate microvalve arrays and a Quake valve, CAM-μTAS delivers cytokine gradients to microglia, mimicking neuroinflammation. Our device automates sample handling and cell culture, enabling rapid media changes in just 1.5 s, thus streamlining the experimental workflow. By analyzing BV2 calcium transient latency to peak, we demonstrate location-dependent microglial activation patterns based on cytokine and ATP gradients, offering insights contrasting those of non-gradient-based perfusion systems. By harnessing advancements in microsystem technology to quantify calcium dynamics, we can construct simplified human models of neurological disorders, unravel the intricate mechanisms of cell-cell signaling, and conduct robust evaluations of novel therapeutics.
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Affiliation(s)
- Adam Shebindu
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX 75080 USA
- Department of Biomedical Engineering, UT Southwestern Medical Center, Dallas, TX 75390 USA
| | - Durga Kaveti
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX 75080 USA
| | - Linda Umutoni
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX 75080 USA
| | - Gia Kirk
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX 75080 USA
| | - Michael D. Burton
- Department of Neuroscience, University of Texas at Dallas, Richardson, TX 75080 USA
| | - Caroline N. Jones
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX 75080 USA
- Department of Biomedical Engineering, UT Southwestern Medical Center, Dallas, TX 75390 USA
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4
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Yu J, Wong S, Lin Z, Shan Z, Fan C, Xia Z, Cheung M, Zhu X, Liu JA, Cheung CW. High-Frequency Spinal Stimulation Suppresses Microglial Kaiso-P2X7 Receptor Axis-Induced Inflammation to Alleviate Neuropathic Pain in Rats. Ann Neurol 2024; 95:966-983. [PMID: 38450773 DOI: 10.1002/ana.26898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 02/05/2024] [Accepted: 02/10/2024] [Indexed: 03/08/2024]
Abstract
OBJECTIVE Neuropathic pain poses a persistent challenge in clinical management. Neuromodulation has emerged as a last-resort therapy. Conventional spinal cord stimulation (Con SCS) often causes abnormal sensations and provides short analgesia, whereas high-frequency spinal cord stimulation (HF SCS) is a newer therapy that effectively alleviates pain without paresthesia. However, the modes of action of 10kHz HF SCS (HF10 SCS) in pain relief remain unclear. To bridge this knowledge gap, we employed preclinical models that mimic certain features of clinical SCS to explore the underlying mechanisms of HF10 SCS. Addressing these issues would provide the scientific basis for improving and evaluating the effectiveness, reliability, and practicality of different frequency SCS in clinical settings. METHODS We established a preclinical SCS model to examine its effects in a neuropathic pain rat model. We conducted bulk and single-cell RNA sequencing in the spinal dorsal horn (SDH) to examine cellular and molecular changes under different treatments. We employed genetic manipulations through intrathecal injection of a lentiviral system to explore the SCS-mediated signaling axis in pain. Various behavioral tests were performed to evaluate pain conditions under different treatments. RESULTS We found that HF10 SCS significantly reduces immune responses in the SDH by inactivating the Kaiso-P2X7R pathological axis in microglia, promoting long-lasting pain relief. Targeting Kaiso-P2X7R in microglia dramatically improved efficacy of Con SCS treatment, leading to reduced neuroinflammation and long-lasting pain relief. INTERPRETATION HF10 SCS could improve the immunopathologic state in the SDH, extending its benefits beyond symptom relief. Targeting the Kaiso-P2X7R axis may enhance Con SCS therapy and offer a new strategy for pain management. ANN NEUROL 2024;95:966-983.
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Affiliation(s)
- Jing Yu
- Department of Anesthesiology, University of Hong Kong, Hong Kong, Hong Kong SAR
| | - Stanley Wong
- Department of Anesthesiology, University of Hong Kong, Hong Kong, Hong Kong SAR
| | - Zhinan Lin
- Department of Neuroscience, City University of Hong Kong, Hong Kong, Hong Kong SAR
| | - Zhiming Shan
- Department of Anesthesiology, University of Hong Kong, Hong Kong, Hong Kong SAR
| | - Chaoyang Fan
- Department of Neuroscience, City University of Hong Kong, Hong Kong, Hong Kong SAR
| | - Zhengyuan Xia
- Department of Anesthesiology, University of Hong Kong, Hong Kong, Hong Kong SAR
- Department of Anesthesiology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Martin Cheung
- School of Biomedical Sciences, University of Hong Kong, Hong Kong, Hong Kong SAR
| | - Xiaowei Zhu
- Department of Neuroscience, City University of Hong Kong, Hong Kong, Hong Kong SAR
| | - Jessica Aijia Liu
- Department of Anesthesiology, University of Hong Kong, Hong Kong, Hong Kong SAR
- Department of Neuroscience, City University of Hong Kong, Hong Kong, Hong Kong SAR
| | - Chi Wai Cheung
- Department of Anesthesiology, University of Hong Kong, Hong Kong, Hong Kong SAR
- Hong Kong Sanatorium Hospital, Hong Kong, Hong Kong SAR
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5
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Poshtkohi A, Wade J, McDaid L, Liu J, Dallas ML, Bithell A. Mathematical Modeling of PI3K/Akt Pathway in Microglia. Neural Comput 2024; 36:645-676. [PMID: 38457763 DOI: 10.1162/neco_a_01643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 11/20/2023] [Indexed: 03/10/2024]
Abstract
The motility of microglia involves intracellular signaling pathways that are predominantly controlled by changes in cytosolic Ca2+ and activation of PI3K/Akt (phosphoinositide-3-kinase/protein kinase B). In this letter, we develop a novel biophysical model for cytosolic Ca2+ activation of the PI3K/Akt pathway in microglia where Ca2+ influx is mediated by both P2Y purinergic receptors (P2YR) and P2X purinergic receptors (P2XR). The model parameters are estimated by employing optimization techniques to fit the model to phosphorylated Akt (pAkt) experimental modeling/in vitro data. The integrated model supports the hypothesis that Ca2+ influx via P2YR and P2XR can explain the experimentally reported biphasic transient responses in measuring pAkt levels. Our predictions reveal new quantitative insights into P2Rs on how they regulate Ca2+ and Akt in terms of physiological interactions and transient responses. It is shown that the upregulation of P2X receptors through a repetitive application of agonist results in a continual increase in the baseline [Ca2+], which causes the biphasic response to become a monophasic response which prolongs elevated levels of pAkt.
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Affiliation(s)
- Alireza Poshtkohi
- School of Physics, Engineering and Computer Science, University of Hertfordshire, Hatfield, Hertfordshire, U.K.
| | - John Wade
- School of Computing, Engineering and Intelligent Systems, University of Ulster, Londonderry, U.K.
| | - Liam McDaid
- School of Computing, Engineering and Intelligent Systems, University of Ulster, Londonderry, U.K.
| | - Junxiu Liu
- School of Computing, Engineering and Intelligent Systems, University of Ulster, Londonderry, U.K.
| | - Mark L Dallas
- School of Pharmacy, University of Reading, Reading, U.K.
| | - Angela Bithell
- School of Pharmacy, University of Reading, Reading, U.K.
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6
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Wallis GJ, Bell LA, Wagner JN, Buxton L, Balachandar L, Wilcox KS. Reactive microglia fail to respond to environmental damage signals in a viral-induced mouse model of temporal lobe epilepsy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.06.583768. [PMID: 38558969 PMCID: PMC10979929 DOI: 10.1101/2024.03.06.583768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Microglia are highly adaptable innate immune cells that rapidly respond to damage signals in the brain through adoption of a reactive phenotype and production of defensive inflammatory cytokines. Microglia express a distinct transcriptome, encoding receptors that allow them to dynamically respond to pathogens, damage signals, and cellular debris. Expression of one such receptor, the microglia-specific purinergic receptor P2ry12, is known to be downregulated in reactive microglia. Here, we explore the microglial response to purinergic damage signals in reactive microglia in the TMEV mouse model of viral brain infection and temporal lobe epilepsy. Using two-photon calcium imaging in acute hippocampal brain slices, we found that the ability of microglia to detect damage signals, engage calcium signaling pathways, and chemoattract towards laser-induced tissue damage was dramatically reduced during the peak period of seizures, cytokine production, and infection. Using combined RNAscope in situ hybridization and immunohistochemistry, we found that during this same stage of heightened infection and seizures, microglial P2ry12 expression was reduced, while the pro-inflammatory cytokine TNF-a expression was upregulated in microglia, suggesting that the depressed ability of microglia to respond to new damage signals via P2ry12 occurs during the time when local elevated cytokine production contributes to seizure generation following infection. Therefore, changes in microglial purinergic receptors during infection likely limit the ability of reactive microglia to respond to new threats in the CNS and locally contain the scale of the innate immune response in the brain.
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Affiliation(s)
- Glenna J Wallis
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 80904
| | - Laura A Bell
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 80904
- Interdepartmental Program in Neuroscience, University of Utah, Salt Lake City, UT, 80904
| | - John N Wagner
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 80904
| | - Lauren Buxton
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 80904
| | - Lakshmini Balachandar
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 80904
| | - Karen S Wilcox
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 80904
- Interdepartmental Program in Neuroscience, University of Utah, Salt Lake City, UT, 80904
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7
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Qian H, Zhang HN, Gao T, Wang XS, Wang X, Yu MY, Li MK, Huang J. Upregulation of TRPC1 in microglia promotes neutrophil infiltration after ischemic stroke. Brain Res Bull 2024; 208:110894. [PMID: 38325758 DOI: 10.1016/j.brainresbull.2024.110894] [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: 12/06/2023] [Revised: 01/22/2024] [Accepted: 02/02/2024] [Indexed: 02/09/2024]
Abstract
Neutrophil infiltration has been linked to worse clinical outcomes after ischemic stroke. Microglia, a key type of immune-competent cell, engage in cross-talk with the infiltrating immune cells in the inflamed brain area, yet the molecular mechanisms involved remain largely unexplored. In this study, we investigated the mechanisms of how canonical transient receptor potential 1 (TRPC1) modulated neutrophil infiltration in male mouse cerebral ischemia and reperfusion injury (CIRI) models. Our findings revealed a notable upregulation of TRPC1 in microglia within both middle cerebral artery occlusion reperfusion (MCAO/R) and in vitro oxygen-glucose deprivation/regeneration (OGD/R) model. Conditional Trpc1 knockdown in microglia markedly reduced infarct volumes and alleviated neurological deficits. Microglia conditional Trpc1 knockdown mice displayed less neutrophil infiltration in peri-infarct area. Trpc1 knockdown microglia exhibited a reduced primed proinflammatory phenotype with less secretion of CC-Chemokines ligand (CCL) 5 and CCL2 after MCAO/R. Blocking CCL5/2 significantly mitigated neutrophil infiltration in microglia/neutrophil transwell co-culture system upon OGD/R condition. Trpc1 knockdown markedly reduced store-operated calcium entry and nuclear factor of activated T-cells c1 (NFATc1) level in OGD/R treated microglia. Overexpression of Nfatc1 reversed the CCL5/2 reducing effect of Trpc1 knockdown, which is mediated by small interfering RNA in BV2 cells upon OGD/R. Our data indicate that upregulation of TRPC1 in microglia stimulates the production of CCL5/2 through the Ca2+/NFATc1 pathway. Upregulated CCL5/2 leads to an increase in neutrophil infiltration into the brain, thereby aggravating reperfusion injury. Our results demonstrate the importance of TRPC1 in microglia-mediated neuroinflammation and suggest a potential means for reducing CIRI induced neurological injury.
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Affiliation(s)
- Hao Qian
- Health Management Center, Second Affiliated Hospital, Fourth Military Medical University, Xi'an 710038, China; Department of Pharmacology, School of Pharmacy, Fourth Military Medical University, Xi'an 710032, China
| | - Hui-Nan Zhang
- Health Management Center, Second Affiliated Hospital, Fourth Military Medical University, Xi'an 710038, China; Department of Neurology, Second Affiliated Hospital, Fourth Military Medical University, Xi'an 710038, China
| | - Tian Gao
- Health Management Center, Second Affiliated Hospital, Fourth Military Medical University, Xi'an 710038, China; Department of Neurology, Second Affiliated Hospital, Fourth Military Medical University, Xi'an 710038, China
| | - Xin-Shang Wang
- Department of Pharmacology, School of Pharmacy, Fourth Military Medical University, Xi'an 710032, China
| | - Xing Wang
- Health Management Center, Second Affiliated Hospital, Fourth Military Medical University, Xi'an 710038, China; Department of Neurology, Second Affiliated Hospital, Fourth Military Medical University, Xi'an 710038, China
| | - Man-Yang Yu
- Health Management Center, Second Affiliated Hospital, Fourth Military Medical University, Xi'an 710038, China; Department of Neurology, Second Affiliated Hospital, Fourth Military Medical University, Xi'an 710038, China
| | - Ming-Kai Li
- Department of Pharmacology, School of Pharmacy, Fourth Military Medical University, Xi'an 710032, China.
| | - Jing Huang
- Health Management Center, Second Affiliated Hospital, Fourth Military Medical University, Xi'an 710038, China; Department of Neurology, Second Affiliated Hospital, Fourth Military Medical University, Xi'an 710038, China.
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8
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Zhao S, Wang L, Liang Y, Zheng J, Umpierre AD, Wu LJ. Chemogenetic activation of microglial Gi signaling decreases microglial surveillance and impairs neuronal synchronization. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.12.579861. [PMID: 38405754 PMCID: PMC10888941 DOI: 10.1101/2024.02.12.579861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Microglia actively survey the brain and dynamically interact with neurons to maintain brain homeostasis. Microglial Gi-protein coupled receptors (Gi-GPCRs) play a critical role in microglia-neuron communications. However, the impact of temporally activating microglial Gi signaling on microglial dynamics and neuronal activity in the homeostatic brain remains largely unknown. In this study, we employed Gi-based Designer Receptors Exclusively Activated by Designer Drugs (Gi-DREADD) to selectively and temporally modulate microglial Gi signaling pathway. By integrating this chemogenetic approach with in vivo two-photon imaging, we observed that exogenous activation of microglial Gi signaling transiently inhibited microglial process dynamics, reduced neuronal activity, and impaired neuronal synchronization. These altered neuronal functions were associated with a decrease in interactions between microglia and neuron somata. Altogether, this study demonstrates that acute, exogenous activation of microglial Gi signaling can regulate neuronal circuit function, offering a potential pharmacological target for neuromodulation through microglia.
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9
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Ma C, Li B, Silverman D, Ding X, Li A, Xiao C, Huang G, Worden K, Muroy S, Chen W, Xu Z, Tso CF, Huang Y, Zhang Y, Luo Q, Saijo K, Dan Y. Microglia regulate sleep through calcium-dependent modulation of norepinephrine transmission. Nat Neurosci 2024; 27:249-258. [PMID: 38238430 PMCID: PMC10849959 DOI: 10.1038/s41593-023-01548-5] [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: 03/29/2023] [Accepted: 12/08/2023] [Indexed: 02/09/2024]
Abstract
Sleep interacts reciprocally with immune system activity, but its specific relationship with microglia-the resident immune cells in the brain-remains poorly understood. Here, we show in mice that microglia can regulate sleep through a mechanism involving Gi-coupled GPCRs, intracellular Ca2+ signaling and suppression of norepinephrine transmission. Chemogenetic activation of microglia Gi signaling strongly promoted sleep, whereas pharmacological blockade of Gi-coupled P2Y12 receptors decreased sleep. Two-photon imaging in the cortex showed that P2Y12-Gi activation elevated microglia intracellular Ca2+, and blockade of this Ca2+ elevation largely abolished the Gi-induced sleep increase. Microglia Ca2+ level also increased at natural wake-to-sleep transitions, caused partly by reduced norepinephrine levels. Furthermore, imaging of norepinephrine with its biosensor in the cortex showed that microglia P2Y12-Gi activation significantly reduced norepinephrine levels, partly by increasing the adenosine concentration. These findings indicate that microglia can regulate sleep through reciprocal interactions with norepinephrine transmission.
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Affiliation(s)
- Chenyan Ma
- Division of Neurobiology, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA, USA
| | - Bing Li
- Division of Neurobiology, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA, USA
| | - Daniel Silverman
- Division of Neurobiology, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA, USA
| | - Xinlu Ding
- Division of Neurobiology, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA, USA
| | - Anan Li
- Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, China
- Research Unit of Multimodal Cross Scale Neural Signal Detection and Imaging, Chinese Academy of Medical Sciences, HUST-Suzhou Institute for Brainmatics, JITRI, Suzhou, China
| | - Chi Xiao
- Key Laboratory of Biomedical Engineering of Hainan Province, School of Biomedical Engineering, Hainan University, Haikou, China
| | - Ganghua Huang
- Key Laboratory of Biomedical Engineering of Hainan Province, School of Biomedical Engineering, Hainan University, Haikou, China
| | - Kurtresha Worden
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, USA
| | - Sandra Muroy
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, USA
| | - Wei Chen
- Department of Physics, University of California, Berkeley, Berkeley, CA, USA
| | - Zhengchao Xu
- Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, China
| | - Chak Foon Tso
- Division of Neurobiology, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA, USA
- , Sunnyvale, CA, USA
| | - Yixuan Huang
- Division of Neurobiology, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA, USA
| | - Yufan Zhang
- Division of Neurobiology, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA, USA
| | - Qingming Luo
- Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, China
- Research Unit of Multimodal Cross Scale Neural Signal Detection and Imaging, Chinese Academy of Medical Sciences, HUST-Suzhou Institute for Brainmatics, JITRI, Suzhou, China
- Key Laboratory of Biomedical Engineering of Hainan Province, School of Biomedical Engineering, Hainan University, Haikou, China
| | - Kaoru Saijo
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, USA
| | - Yang Dan
- Division of Neurobiology, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA, USA.
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10
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Garaschuk O, Verkhratsky A. Calcium Signalling in Microglia. ADVANCES IN NEUROBIOLOGY 2024; 37:123-133. [PMID: 39207689 DOI: 10.1007/978-3-031-55529-9_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
Intracellular Ca2+ signalling represents the substrate of microglial excitability. Spatially and temporally organised changes in the free cytoplasmic Ca2+ concentration ([Ca2+]i) are generated in response to physiological and pathological stimuli. Parameters of these intracellular Ca2+ signals are defined by Ca2+ signalling toolkits that may change with age or context therefore increasing adaptive capabilities of microglia. Main Ca2+ signalling pathways in microglial cells are associated with dynamic endoplasmic reticulum Ca2+ stores and with plasmalemmal Ca2+ entry mediated by several sets of Ca2+-permeable channels including transient receptor potential (TRP) channels, ORAI channels and P2X4/7 purinoceptors. Microglial Ca2+ dynamics is also linked to TREM2 signalling cascade, contributing to neuroprotection in neurodegenerative diseases. Microglial Ca2+ signals act as reliable and precise sensors of brain dyshomeostasis and pathological insults.
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Affiliation(s)
- Olga Garaschuk
- Institute of Physiology, Department Neurophysiology, Eberhard Karls University of Tübingen, Tübingen, Germany.
| | - Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK.
- Department of Neurosciences, University of the Basque Country, Leioa, Spain.
- Department of Stem Cell Biology, State Research Institute Centre for Innovative Medicine, LT-01102, Vilnius, Lithuania.
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
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11
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Dheer A, Bosco DB, Zheng J, Wang L, Zhao S, Haruwaka K, Yi MH, Barath A, Tian DS, Wu LJ. Chemogenetic approaches reveal dual functions of microglia in seizures. Brain Behav Immun 2024; 115:406-418. [PMID: 37926132 PMCID: PMC10841657 DOI: 10.1016/j.bbi.2023.11.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 10/14/2023] [Accepted: 11/02/2023] [Indexed: 11/07/2023] Open
Abstract
Microglia are key players in maintaining brain homeostasis and exhibit phenotypic alterations in response to epileptic stimuli. However, it is still relatively unknown if these alterations are pro- or anti-epileptic. To unravel this dilemma, we employed chemogenetic manipulation of microglia using the artificial Gi-Dreadd receptor within a kainic acid (KA) induced murine seizure model. Our results indicate that acute Gi-Dreadd activation with Clozapine-N-Oxide can reduce seizure severity. Additionally, we observed increased interaction between microglia and neuronal soma, which correlated with reduced neuronal hyperactivity. Interestingly, prolonged activation of microglial Gi-Dreadds by repeated doses of CNO over 3 days, arrested microglia in a less active, homeostatic-like state, which associated with increased neuronal loss after KA induced seizures. RNAseq analysis revealed that prolonged activation of Gi-Dreadd interferes with interferon β signaling and microglia proliferation. Thus, our findings highlight the importance of microglial Gi signaling not only during status epilepticus (SE) but also within later seizure induced pathology.
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Affiliation(s)
- Aastha Dheer
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | - Dale B Bosco
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | - Jiaying Zheng
- Department of Neurology, Mayo Clinic, Rochester, MN, USA; Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN, USA
| | - Lingxiao Wang
- Department of Neurology, Mayo Clinic, Rochester, MN, USA; Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN, USA
| | - Shunyi Zhao
- Department of Neurology, Mayo Clinic, Rochester, MN, USA; Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN, USA
| | | | - Min-Hee Yi
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | - Abhijeet Barath
- Department of Neurology, Mayo Clinic, Rochester, MN, USA; Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN, USA
| | - Dai-Shi Tian
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Long-Jun Wu
- Department of Neurology, Mayo Clinic, Rochester, MN, USA; Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA; Department of Immunology, Mayo Clinic, Rochester, MN, USA.
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12
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Pan K, Garaschuk O. The role of intracellular calcium-store-mediated calcium signals in in vivo sensor and effector functions of microglia. J Physiol 2023; 601:4203-4215. [PMID: 35315518 DOI: 10.1113/jp279521] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 03/09/2022] [Indexed: 11/08/2022] Open
Abstract
Under physiological conditions microglia, the immune sentinels of the brain, constantly monitor their microenvironment. In the case of danger, damage or cell/tissue dyshomeostasis, they react with changes in process motility, polarization, directed process movement, morphology and gene expression profile; release pro- and anti-inflammatory mediators; proliferate; and clean brain parenchyma by means of phagocytosis. Based on recent transcriptomic and in vivo Ca2+ imaging data, we argue that the local cell/tissue dyshomeostasis is sensed by microglia via intracellular Ca2+ signals, many of which are mediated by Ca2+ release from the intracellular Ca2+ stores. These signals encode the strength, duration and spatiotemporal pattern of the stimulus and, at the same time, relay this information further to trigger the respective Ca2+ -dependent effector pathways. We also point to the fact that microglial Ca2+ signalling is sexually dimorphic and undergoes profound changes across the organism's lifespan. Interestingly, the first changes in microglial Ca2+ signalling are visible already in 9- to 11-month-old mice, roughly corresponding to 40-year-old humans.
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Affiliation(s)
- Kuang Pan
- Institute of Physiology, Department of Neurophysiology, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Olga Garaschuk
- Institute of Physiology, Department of Neurophysiology, Eberhard Karls University of Tübingen, Tübingen, Germany
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13
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Feng L, Lo H, Hong Z, Zheng J, Yan Y, Ye Z, Chen X, Pan X. Microglial LRRK2-mediated NFATc1 attenuates α-synuclein immunotoxicity in association with CX3CR1-induced migration and the lysosome-initiated degradation. Glia 2023; 71:2266-2284. [PMID: 37300531 DOI: 10.1002/glia.24422] [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: 01/30/2023] [Revised: 04/22/2023] [Accepted: 05/22/2023] [Indexed: 06/12/2023]
Abstract
Synucleinopathies refer to a range of neurodegenerative diseases caused by abnormal α-synuclein (α-Syn) deposition, including Parkinson's disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA). Their pathogenesis is strongly linked to microglial dysfunction and neuroinflammation, which involves the leucine-rich-repeat kinase 2 (LRRK2)-regulated nuclear factor of activated T-cells (NFAT). Of the NFAT family, NFATc1 has been found to be increasingly translocated into the nucleus in α-syn stimulation. However, the specific role of NFATc1-mediated intracellular signaling in PD remains elusive in regulating microglial functions. In the current study, we crossbred LRRK2 or NFATc1 conditional knockout mice with Lyz2Cre mice to generate mice with microglia-specific deletion of LRRK2 or NFATc1, and by stereotactic injection of fibrillary α-Syn, we generated PD models in these mice. We found that LRRK2 deficiency enhanced microglial phagocytosis in the mice after α-Syn exposure and that genetic inhibition of NFATc1 markedly diminished phagocytosis and α-Syn elimination. We further demonstrated that LRRK2 negatively regulated NFATc1 in α-Syn-treated microglia, in which microglial LRRK2-deficiency facilitated NFATc1 nuclear translocation, CX3CR1 upregulation, and microglia migration. Additionally, NFATc1 translocation upregulated the expression of Rab7 and promoted the formation of late lysosomes, resulting in α-Syn degradation. In contrast, the microglial NFATc1 deficiency impaired CX3CR1 upregulation and the formation of Rab7-mediated late lysosomes. These findings highlight the critical role of NFATc1 in modulating microglial migration and phagocytosis, in which the LRRK2-NFATc1 signaling pathway regulates the expression of microglial CX3CR1 and endocytic degradative Rab7 to attenuate α-synuclein immunotoxicity.
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Affiliation(s)
- Linjuan Feng
- Department of Neurology, Center for Cognitive Neurology, Fujian Medical University Union Hospital, Fuzhou, China
- Fujian Institute of Geriatrics, Fujian Medical University Union Hospital, Fuzhou, China
- Institute of Clinical Neurology, Fujian Medical University, Fuzhou, China
- Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, China
| | - Hsuan Lo
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Zhaoxiang Hong
- Department of Neurology, Center for Cognitive Neurology, Fujian Medical University Union Hospital, Fuzhou, China
- Fujian Institute of Geriatrics, Fujian Medical University Union Hospital, Fuzhou, China
- Department of Neurology, The University of HongKong Shenzhen Hospital, Shenzhen, Guangdong, China
| | - Jiahao Zheng
- Department of Neurology, Center for Cognitive Neurology, Fujian Medical University Union Hospital, Fuzhou, China
- Fujian Institute of Geriatrics, Fujian Medical University Union Hospital, Fuzhou, China
- Institute of Clinical Neurology, Fujian Medical University, Fuzhou, China
- Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, China
| | - Yuhong Yan
- Department of Neurology, Center for Cognitive Neurology, Fujian Medical University Union Hospital, Fuzhou, China
- Fujian Institute of Geriatrics, Fujian Medical University Union Hospital, Fuzhou, China
- Institute of Clinical Neurology, Fujian Medical University, Fuzhou, China
- Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, China
| | - Zucheng Ye
- Key Laboratory of Brain Aging and Neurodegenerative Diseases, Fujian Medical University, Fuzhou, China
| | - Xiaochun Chen
- Department of Neurology, Center for Cognitive Neurology, Fujian Medical University Union Hospital, Fuzhou, China
- Institute of Clinical Neurology, Fujian Medical University, Fuzhou, China
- Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, China
| | - Xiaodong Pan
- Department of Neurology, Center for Cognitive Neurology, Fujian Medical University Union Hospital, Fuzhou, China
- Fujian Institute of Geriatrics, Fujian Medical University Union Hospital, Fuzhou, China
- Institute of Clinical Neurology, Fujian Medical University, Fuzhou, China
- Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, China
- Key Laboratory of Brain Aging and Neurodegenerative Diseases, Fujian Medical University, Fuzhou, China
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14
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Tsujikawa S, DeMeulenaere KE, Centeno MV, Ghazisaeidi S, Martin ME, Tapies MR, Maneshi MM, Yamashita M, Stauderman KA, Apkarian AV, Salter MW, Prakriya M. Regulation of neuropathic pain by microglial Orai1 channels. SCIENCE ADVANCES 2023; 9:eade7002. [PMID: 36706180 PMCID: PMC9883051 DOI: 10.1126/sciadv.ade7002] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 12/23/2022] [Indexed: 06/01/2023]
Abstract
Microglia are important mediators of neuroinflammation, which underlies neuropathic pain. However, the molecular checkpoints controlling microglial reactivity are not well-understood. Here, we investigated the role of Orai1 channels for microglia-mediated neuroinflammation following nerve injury and find that deletion of Orai1 in microglia attenuates Ca2+ signaling and the production of inflammatory cytokines by proalgesic agonists. Conditional deletion of Orai1 attenuated microglial proliferation in the dorsal horn, spinal cytokine levels, and potentiation of excitatory neurotransmission following peripheral nerve injury. These cellular effects were accompanied by mitigation of pain hyperalgesia in microglial Orai1 knockout mice. A small-molecule Orai1 inhibitor, CM4620, similarly mitigated allodynia in male mice. Unexpectedly, these protective effects were not seen in female mice, revealing sexual dimorphism in Orai1 regulation of microglial reactivity and hyperalgesia. Together, these findings indicate that Orai1 channels are key regulators of the sexually dimorphic role of microglia for the neuroinflammation that underlies neuropathic pain.
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Affiliation(s)
- Shogo Tsujikawa
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Kaitlyn E. DeMeulenaere
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Maria V. Centeno
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | | | - Megan E. Martin
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Martinna R. Tapies
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Mohammad M. Maneshi
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Megumi Yamashita
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | | | - Apkar V. Apkarian
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | | | - Murali Prakriya
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
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15
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Arnst N, Redolfi N, Lia A, Bedetta M, Greotti E, Pizzo P. Mitochondrial Ca 2+ Signaling and Bioenergetics in Alzheimer's Disease. Biomedicines 2022; 10:3025. [PMID: 36551781 PMCID: PMC9775979 DOI: 10.3390/biomedicines10123025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 11/17/2022] [Accepted: 11/22/2022] [Indexed: 11/25/2022] Open
Abstract
Alzheimer's disease (AD) is a hereditary and sporadic neurodegenerative illness defined by the gradual and cumulative loss of neurons in specific brain areas. The processes that cause AD are still under investigation and there are no available therapies to halt it. Current progress puts at the forefront the "calcium (Ca2+) hypothesis" as a key AD pathogenic pathway, impacting neuronal, astrocyte and microglial function. In this review, we focused on mitochondrial Ca2+ alterations in AD, their causes and bioenergetic consequences in neuronal and glial cells, summarizing the possible mechanisms linking detrimental mitochondrial Ca2+ signals to neuronal death in different experimental AD models.
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Affiliation(s)
- Nikita Arnst
- Department of Biomedical Sciences, University of Padova, 35131 Padua, Italy
| | - Nelly Redolfi
- Department of Biomedical Sciences, University of Padova, 35131 Padua, Italy
| | - Annamaria Lia
- Department of Biomedical Sciences, University of Padova, 35131 Padua, Italy
- Neuroscience Institute, Italian National Research Council (CNR), 35131 Padua, Italy
| | - Martina Bedetta
- Department of Biomedical Sciences, University of Padova, 35131 Padua, Italy
| | - Elisa Greotti
- Department of Biomedical Sciences, University of Padova, 35131 Padua, Italy
- Neuroscience Institute, Italian National Research Council (CNR), 35131 Padua, Italy
- Padova Neuroscience Center (PNC), University of Padova, 35131 Padua, Italy
| | - Paola Pizzo
- Department of Biomedical Sciences, University of Padova, 35131 Padua, Italy
- Neuroscience Institute, Italian National Research Council (CNR), 35131 Padua, Italy
- Study Centre for Neurodegeneration (CESNE), University of Padova, 35131 Padua, Italy
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16
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Okada Y, Hosoi N, Matsuzaki Y, Fukai Y, Hiraga A, Nakai J, Nitta K, Shinohara Y, Konno A, Hirai H. Development of microglia-targeting adeno-associated viral vectors as tools to study microglial behavior in vivo. Commun Biol 2022; 5:1224. [DOI: 10.1038/s42003-022-04200-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 10/31/2022] [Indexed: 11/13/2022] Open
Abstract
AbstractHere we describe the microglia-targeting adeno-associated viral (AAV) vectors containing a 1.7-kb putative promoter region of microglia/macrophage-specific ionized calcium-binding adaptor molecule 1 (Iba1), along with repeated miRNA target sites for microRNA (miR)-9 and miR-129-2-3p. The 1.7-kb genomic sequence upstream of the start codon in exon 1 of the Iba1 (Aif1) gene, functions as microglia preferential promoter in the striatum and cerebellum. Furthermore, ectopic transgene expression in non-microglial cells is markedly suppressed upon adding two sets of 4-repeated miRNA target sites for miR-9 and miR-129-2-3p, which are expressed exclusively in non-microglial cells and sponged AAV-derived mRNAs. Our vectors transduced ramified microglia in healthy tissues and reactive microglia in lipopolysaccharide-treated mice and a mouse model of neurodegenerative disease. Moreover, live fluorescent imaging allowed the monitoring of microglial motility and intracellular Ca2+ mobilization. Thus, microglia-targeting AAV vectors are valuable for studying microglial pathophysiology and therapies, particularly in the striatum and cerebellum.
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17
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Role of Microglia and Astrocytes in Alzheimer’s Disease: From Neuroinflammation to Ca2+ Homeostasis Dysregulation. Cells 2022; 11:cells11172728. [PMID: 36078138 PMCID: PMC9454513 DOI: 10.3390/cells11172728] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 08/26/2022] [Accepted: 08/30/2022] [Indexed: 12/12/2022] Open
Abstract
Alzheimer’s disease (AD) is the most common form of dementia worldwide, with a complex, poorly understood pathogenesis. Cerebral atrophy, amyloid-β (Aβ) plaques, and neurofibrillary tangles represent the main pathological hallmarks of the AD brain. Recently, neuroinflammation has been recognized as a prominent feature of the AD brain and substantial evidence suggests that the inflammatory response modulates disease progression. Additionally, dysregulation of calcium (Ca2+) homeostasis represents another early factor involved in the AD pathogenesis, as intracellular Ca2+ concentration is essential to ensure proper cellular and neuronal functions. Although growing evidence supports the involvement of Ca2+ in the mechanisms of neurodegeneration-related inflammatory processes, scant data are available on its contribution in microglia and astrocytes functioning, both in health and throughout the AD continuum. Nevertheless, AD-related aberrant Ca2+ signalling in astrocytes and microglia is crucially involved in the mechanisms underpinning neuroinflammatory processes that, in turn, impact neuronal Ca2+ homeostasis and brain function. In this light, we attempted to provide an overview of the current understanding of the interactions between the glia cells-mediated inflammatory responses and the molecular mechanisms involved in Ca2+ homeostasis dysregulation in AD.
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18
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Zhang R, Zhou T, Samanta S, Luo Z, Li S, Xu H, Qu J. Synergistic photobiomodulation with 808-nm and 1064-nm lasers to reduce the β-amyloid neurotoxicity in the in vitro Alzheimer's disease models. FRONTIERS IN NEUROIMAGING 2022; 1:903531. [PMID: 37555169 PMCID: PMC10406259 DOI: 10.3389/fnimg.2022.903531] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 05/11/2022] [Indexed: 08/10/2023]
Abstract
BACKGROUND In Alzheimer's disease (AD), the deposition of β-amyloid (Aβ) plaques is closely associated with the neuronal apoptosis and activation of microglia, which may result in the functional impairment of neurons through pro-inflammation and over-pruning of the neurons. Photobiomodulation (PBM) is a non-invasive therapeutic approach without any conspicuous side effect, which has shown promising attributes in the treatment of chronic brain diseases such as AD by reducing the Aβ burden. However, neither the optimal parameters for PBM treatment nor its exact role in modulating the microglial functions/activities has been conclusively established yet. METHODS An inflammatory stimulation model of Alzheimer's disease (AD) was set up by activating microglia and neuroblastoma with fibrosis β-amyloid (fAβ) in a transwell insert system. SH-SY5Y neuroblastoma cells and BV2 microglial cells were irradiated with the 808- and 1,064-nm lasers, respectively (a power density of 50 mW/cm2 and a dose of 10 J/cm2) to study the PBM activity. The amount of labeled fAβ phagocytosed by microglia was considered to assess the microglial phagocytosis. A PBM-induced neuroprotective study was conducted with the AD model under different laser parameters to realize the optimal condition. Microglial phenotype, microglial secretions of the pro-inflammatory and anti-inflammatory factors, and the intracellular Ca2+ levels in microglia were studied in detail to understand the structural and functional changes occurring in the microglial cells of AD model upon PBM treatment. CONCLUSION A synergistic PBM effect (with the 808- and 1,064-nm lasers) effectively inhibited the fAβ-induced neurotoxicity of neuroblastoma by promoting the viability of neuroblastoma and regulating the intracellular Ca2+ levels of microglia. Moreover, the downregulation of Ca2+ led to microglial polarization with an M2 phenotype, which promotes the fAβ phagocytosis, and resulted in the upregulated expression of anti-inflammatory factors and downregulated expression of inflammatory factors.
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Affiliation(s)
| | | | | | | | | | | | - Junle Qu
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, China
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19
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Wendimu MY, Hooks SB. Microglia Phenotypes in Aging and Neurodegenerative Diseases. Cells 2022; 11:2091. [PMID: 35805174 PMCID: PMC9266143 DOI: 10.3390/cells11132091] [Citation(s) in RCA: 91] [Impact Index Per Article: 45.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 06/24/2022] [Accepted: 06/29/2022] [Indexed: 02/08/2023] Open
Abstract
Neuroinflammation is a hallmark of many neurodegenerative diseases (NDs) and plays a fundamental role in mediating the onset and progression of disease. Microglia, which function as first-line immune guardians of the central nervous system (CNS), are the central drivers of neuroinflammation. Numerous human postmortem studies and in vivo imaging analyses have shown chronically activated microglia in patients with various acute and chronic neuropathological diseases. While microglial activation is a common feature of many NDs, the exact role of microglia in various pathological states is complex and often contradictory. However, there is a consensus that microglia play a biphasic role in pathological conditions, with detrimental and protective phenotypes, and the overall response of microglia and the activation of different phenotypes depends on the nature and duration of the inflammatory insult, as well as the stage of disease development. This review provides a comprehensive overview of current research on the various microglia phenotypes and inflammatory responses in health, aging, and NDs, with a special emphasis on the heterogeneous phenotypic response of microglia in acute and chronic diseases such as hemorrhagic stroke (HS), Alzheimer's disease (AD), and Parkinson's disease (PD). The primary focus is translational research in preclinical animal models and bulk/single-cell transcriptome studies in human postmortem samples. Additionally, this review covers key microglial receptors and signaling pathways that are potential therapeutic targets to regulate microglial inflammatory responses during aging and in NDs. Additionally, age-, sex-, and species-specific microglial differences will be briefly reviewed.
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Affiliation(s)
| | - Shelley B. Hooks
- Hooks Lab, Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, GA 30602, USA;
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20
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Venugopal D, Vishwakarma S, Kaur I, Samavedi S. Electrospun fiber-based strategies for controlling early innate immune cell responses: Towards immunomodulatory mesh designs that facilitate robust tissue repair. Acta Biomater 2022; 163:228-247. [PMID: 35675893 DOI: 10.1016/j.actbio.2022.06.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 05/16/2022] [Accepted: 06/01/2022] [Indexed: 12/16/2022]
Abstract
Electrospun fibrous meshes are widely used for tissue repair due to their ability to guide a host of cell responses including phenotypic differentiation and tissue maturation. A critical factor determining the eventual biological outcomes of mesh-based regeneration strategies is the early innate immune response following implantation. The natural healing process involves a sequence of tightly regulated, temporally varying and delicately balanced pro-/anti-inflammatory events which together promote mesh integration with host tissue. Matrix designs that do not account for the immune milieu can result in dysregulation, chronic inflammation and fibrous capsule formation, thus obliterating potential therapeutic outcomes. In this review, we provide systematic insights into the effects of specific fiber/mesh properties and mechanical stimulation on the responses of early innate immune modulators viz., neutrophils, monocytes and macrophages. We identify matrix characteristics that promote anti-inflammatory immune phenotypes, and we correlate such responses with pro-regenerative in vivo outcomes. We also discuss recent advances in 3D fabrication technologies, bioactive functionalization approaches and biomimetic/bioinspired immunomodulatory mesh design strategies for tissue repair and wound healing. The mechanobiological insights and immunoregulatory strategies discussed herein can help improve the translational outcomes of fiber-based regeneration and may also be leveraged for intervention in degenerative diseases associated with dysfunctional immune responses. STATEMENT OF SIGNIFICANCE: The crucial role played by immune cells in promoting biomaterial-based tissue regeneration is being increasingly recognized. In this review focusing on the interactions of innate immune cells (primarily neutrophils, monocytes and macrophages) with electrospun fibrous meshes, we systematically elucidate the effects of the fiber microenvironment and mechanical stimulation on biological responses, and build upon these insights to inform the rational design of immunomodulatory meshes for effective tissue repair. We discuss state-of-the-art fabrication methods and mechanobiological advances that permit the orchestration of temporally controlled phenotypic switches in immune cells during different phases of healing. The design strategies discussed herein can also be leveraged to target several complex autoimmune and inflammatory diseases.
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21
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Zhou R, Qian S, Cho WCS, Zhou J, Jin C, Zhong Y, Wang J, Zhang X, Xu Z, Tian M, Chan LWC, Zhang H. Microbiota-microglia connections in age-related cognition decline. Aging Cell 2022; 21:e13599. [PMID: 35349746 PMCID: PMC9124309 DOI: 10.1111/acel.13599] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 03/08/2022] [Accepted: 03/13/2022] [Indexed: 12/13/2022] Open
Abstract
Aging is an inevitable process that all individuals experience, of which the extent differs among individuals. It has been recognized as the risk factor of neurodegenerative diseases by affecting gut microbiota compositions, microglia, and cognition abilities. Aging‐induced changes in gut microbiota compositions have a critical role in orchestrating the morphology and functions of microglia through the gut‐brain axis. Gut microbiota communicates with microglia by its secreted metabolites and neurotransmitters. This is highly associated with age‐related cognitive declines. Here, we review the main composition of microbiota in the aged individuals, outline the changes of the brain in age‐related cognitive decline from a neuroinflammation perspective, especially the changes of morphology and functions of microglia, discuss the crosstalk between microbiota and microglia in the aged brain and further highlight the role of microbiota‐microglia connections in neurodegenerative diseases (Alzheimer's disease and Parkinson's disease).
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Affiliation(s)
- Rui Zhou
- Department of Nuclear Medicine and Medical PET Center The Second Affiliated Hospital of Zhejiang University School of Medicine Hangzhou China
- Department of Health Technology and Informatics The Hong Kong Polytechnic University Hong Kong SAR China
| | - Shufang Qian
- Department of Nuclear Medicine and Medical PET Center The Second Affiliated Hospital of Zhejiang University School of Medicine Hangzhou China
| | - William C. S. Cho
- Department of Clinical Oncology Queen Elizabeth Hospital Hong Kong SAR China
| | - Jinyun Zhou
- Department of Nuclear Medicine and Medical PET Center The Second Affiliated Hospital of Zhejiang University School of Medicine Hangzhou China
| | - Chentao Jin
- Department of Nuclear Medicine and Medical PET Center The Second Affiliated Hospital of Zhejiang University School of Medicine Hangzhou China
| | - Yan Zhong
- Department of Nuclear Medicine and Medical PET Center The Second Affiliated Hospital of Zhejiang University School of Medicine Hangzhou China
| | - Jing Wang
- Department of Nuclear Medicine and Medical PET Center The Second Affiliated Hospital of Zhejiang University School of Medicine Hangzhou China
| | - Xiaohui Zhang
- Department of Nuclear Medicine and Medical PET Center The Second Affiliated Hospital of Zhejiang University School of Medicine Hangzhou China
| | - Zhoujiao Xu
- Department of Nuclear Medicine and Medical PET Center The Second Affiliated Hospital of Zhejiang University School of Medicine Hangzhou China
| | - Mei Tian
- Department of Nuclear Medicine and Medical PET Center The Second Affiliated Hospital of Zhejiang University School of Medicine Hangzhou China
| | - Lawrence W. C. Chan
- Department of Health Technology and Informatics The Hong Kong Polytechnic University Hong Kong SAR China
| | - Hong Zhang
- Department of Nuclear Medicine and Medical PET Center The Second Affiliated Hospital of Zhejiang University School of Medicine Hangzhou China
- Key Laboratory for Biomedical Engineering of Ministry of Education Zhejiang University Hangzhou China
- The College of Biomedical Engineering and Instrument Science of Zhejiang University Hangzhou China
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22
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Comparison of Microglial Morphology and Function in Primary Cerebellar Cell Cultures on Collagen and Collagen-Mimetic Hydrogels. Biomedicines 2022; 10:biomedicines10051023. [PMID: 35625762 PMCID: PMC9139096 DOI: 10.3390/biomedicines10051023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 04/21/2022] [Accepted: 04/26/2022] [Indexed: 12/07/2022] Open
Abstract
Neuronal-glial cell cultures are usually grown attached to or encapsulated in an adhesive environment as evenly distributed networks lacking tissue-like cell density, organization and morphology. In such cultures, microglia have activated amoeboid morphology and do not display extended and intensively branched processes characteristic of the ramified tissue microglia. We have recently described self-assembling functional cerebellar organoids promoted by hydrogels containing collagen-like peptides (CLPs) conjugated to a polyethylene glycol (PEG) core. Spontaneous neuronal activity was accompanied by changes in the microglial morphology and behavior, suggesting the cells might play an essential role in forming the functional neuronal networks in response to the peptide signalling. The present study examines microglial cell morphology and function in cerebellar cell organoid cultures on CLP-PEG hydrogels and compares them to the cultures on crosslinked collagen hydrogels of similar elastomechanical properties. Material characterization suggested more expressed fibril orientation and denser packaging in crosslinked collagen than CLP-PEG. However, CLP-PEG promoted a significantly higher microglial motility (determined by time-lapse imaging) accompanied by highly diverse morphology including the ramified (brightfield and confocal microscopy), more active Ca2+ signalling (intracellular Ca2+ fluorescence recordings), and moderate inflammatory cytokine level (ELISA). On the contrary, on the collagen hydrogels, microglial cells were significantly less active and mostly round-shaped. In addition, the latter hydrogels did not support the neuron synaptic activity. Our findings indicate that the synthetic CLP-PEG hydrogels ensure more tissue-like microglial morphology, motility, and function than the crosslinked collagen substrates.
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Rieder P, Gobbo D, Stopper G, Welle A, Damo E, Kirchhoff F, Scheller A. Astrocytes and Microglia Exhibit Cell-Specific Ca2+ Signaling Dynamics in the Murine Spinal Cord. Front Mol Neurosci 2022; 15:840948. [PMID: 35431801 PMCID: PMC9006623 DOI: 10.3389/fnmol.2022.840948] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 02/22/2022] [Indexed: 12/31/2022] Open
Abstract
The spinal cord is the main pathway connecting brain and peripheral nervous system. Its functionality relies on the orchestrated activity of both neurons and glial cells. To date, most advancement in understanding the spinal cord inner mechanisms has been made either by in vivo exposure of its dorsal surface through laminectomy or by acute ex vivo slice preparation, likely affecting spinal cord physiology in virtue of the necessary extensive manipulation of the spinal cord tissue. This is especially true of cells immediately responding to alterations of the surrounding environment, such as microglia and astrocytes, reacting within seconds or minutes and for up to several days after the original insult. Ca2+ signaling is considered one of the most immediate, versatile, and yet elusive cellular responses of glia. Here, we induced the cell-specific expression of the genetically encoded Ca2+ indicator GCaMP3 to evaluate spontaneous intracellular Ca2+ signaling in astrocytes and microglia. Ca2+ signals were then characterized in acute ex vivo (both gray and white matter) as well as in chronic in vivo (white matter) preparations using MSparkles, a MATLAB-based software for automatic detection and analysis of fluorescence events. As a result, we were able to segregate distinct astroglial and microglial Ca2+ signaling patterns along with method-specific Ca2+ signaling alterations, which must be taken into consideration in the reliable evaluation of any result obtained in physiological as well as pathological conditions. Our study revealed a high degree of Ca2+ signaling diversity in glial cells of the murine spinal cord, thus adding to the current knowledge of the astonishing glial heterogeneity and cell-specific Ca2+ dynamics in non-neuronal networks.
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Affiliation(s)
- Phillip Rieder
- Department of Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Homburg, Germany
| | - Davide Gobbo
- Department of Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Homburg, Germany
| | - Gebhard Stopper
- Department of Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Homburg, Germany
| | - Anna Welle
- Department of Genetics and Epigenetics, University of Saarland, Saarbrücken, Germany
| | - Elisa Damo
- Department of Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Homburg, Germany
- Institute of Pharmacology, Medical Faculty Heidelberg, Heidelberg University, Heidelberg, Germany
| | - Frank Kirchhoff
- Department of Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Homburg, Germany
| | - Anja Scheller
- Department of Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Homburg, Germany
- *Correspondence: Anja Scheller,
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Microglia Modulate Cortical Spreading Depolarizations After Ischemic Stroke: A Narrative Review. Neurocrit Care 2022; 37:133-138. [PMID: 35288861 PMCID: PMC9259539 DOI: 10.1007/s12028-022-01469-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 02/08/2022] [Indexed: 01/06/2023]
Abstract
Cortical spreading depolarizations (CSDs) are characterized by waves of diminished electroencephalography activity that propagate across the cortex with subsequent loss of ionic homeostasis. CSDs have been found in many pathological conditions, including migraine, traumatic brain injury, and ischemic stroke. Because of CSD-associated ionic and metabolic disturbances at the peri-infarct area after ischemic stroke, it is thought that CSDs exacerbate tissue infarction and worsen clinical outcomes. Microglia, the main innate immune cells in the brain, are among the first responders to brain tissue damage. Recent studies demonstrated that microglia play a critical role in CSD initiation and propagation. In this article, we discuss the significance of CSD in the setting of ischemic stroke and how microglia may modulate peri-infarct CSDs, also known as iso-electric depolarizations. Finally, we discuss the significance of microglial Ca2+ and how it might be used as a potential therapeutic target for patients with ischemic stroke.
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Logiacco F, Xia P, Georgiev SV, Franconi C, Chang YJ, Ugursu B, Sporbert A, Kühn R, Kettenmann H, Semtner M. Microglia sense neuronal activity via GABA in the early postnatal hippocampus. Cell Rep 2021; 37:110128. [PMID: 34965412 DOI: 10.1016/j.celrep.2021.110128] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 09/14/2021] [Accepted: 11/22/2021] [Indexed: 01/05/2023] Open
Abstract
Microglia, the resident macrophages in the central nervous system, express receptors for classical neurotransmitters, such as γ-aminobutyric acid (GABA) and glutamate, suggesting that they sense synaptic activity. To detect microglial Ca2+ responses to neuronal activity, we generate transgenic mouse lines expressing the fluorescent Ca2+ indicator GCaMP6m, specifically in microglia and demonstrate that electrical stimulation of the Schaffer collateral pathway results in microglial Ca2+ responses in early postnatal but not adult hippocampus. Preceding the microglial responses, we also observe similar Ca2+ responses in astrocytes, and both are sensitive to tetrodotoxin. Blocking astrocytic glutamate uptake or GABA transport abolishes stimulation-induced microglial responses as well as antagonizing the microglial GABAB receptor. Our data, therefore, suggest that the neuronal activity-induced glutamate uptake and the release of GABA by astrocytes trigger the activation of GABAB receptors in microglia. This neuron, astrocyte, and microglia communication pathway might modulate microglial activity in developing neuronal networks.
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Affiliation(s)
- Francesca Logiacco
- Cellular Neurosciences, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany; Department of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, 12169 Berlin, Germany
| | - Pengfei Xia
- Cellular Neurosciences, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
| | - Svilen Veselinov Georgiev
- Cellular Neurosciences, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
| | - Celeste Franconi
- Cellular Neurosciences, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
| | - Yi-Jen Chang
- Cellular Neurosciences, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
| | - Bilge Ugursu
- Cellular Neurosciences, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany; Experimental Ophthalmology, Charité Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Anje Sporbert
- Advanced Light Microscopy, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
| | - Ralf Kühn
- Transgenic Core Facility, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
| | - Helmut Kettenmann
- Cellular Neurosciences, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany; Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Marcus Semtner
- Cellular Neurosciences, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany.
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In Vitro Model to Investigate Communication between Dorsal Root Ganglion and Spinal Cord Glia. Int J Mol Sci 2021; 22:ijms22189725. [PMID: 34575886 PMCID: PMC8470479 DOI: 10.3390/ijms22189725] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/02/2021] [Accepted: 09/03/2021] [Indexed: 12/30/2022] Open
Abstract
Chronic discogenic back pain is associated with increased inflammatory cytokine levels that can influence the proximal peripheral nervous system, namely the dorsal root ganglion (DRG). However, transition to chronic pain is widely thought to involve glial activation in the spinal cord. In this study, an in vitro model was used to evaluate the communication between DRG and spinal cord glia. Primary neonatal rat DRG cells were treated with/without inflammatory cytokines (TNF-α, IL-1β, and IL-6). The conditioned media were collected at two time points (12 and 24 h) and applied to spinal cord mixed glial culture (MGC) for 24 h. Adult bovine DRG and spinal cord cell cultures were also tested, as an alternative large animal model, and results were compared with the neonatal rat findings. Compared with untreated DRG-conditioned medium, the second cytokine-treated DRG-conditioned medium (following medium change, thus containing solely DRG-derived molecules) elevated CD11b expression and calcium signal in neonatal rat microglia and enhanced Iba1 expression in adult bovine microglia. Cytokine treatment induced a DRG-mediated microgliosis. The described in vitro model allows the use of cells from large species and may represent an alternative to animal pain models (3R principles).
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Effects of Metformin on Spontaneous Ca 2+ Signals in Cultured Microglia Cells under Normoxic and Hypoxic Conditions. Int J Mol Sci 2021; 22:ijms22179493. [PMID: 34502402 PMCID: PMC8430509 DOI: 10.3390/ijms22179493] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 08/20/2021] [Accepted: 08/28/2021] [Indexed: 12/12/2022] Open
Abstract
Microglial functioning depends on Ca2+ signaling. By using Ca2+ sensitive fluorescence dye, we studied how inhibition of mitochondrial respiration changed spontaneous Ca2+ signals in soma of microglial cells from 5-7-day-old rats grown under normoxic and mild-hypoxic conditions. In microglia under normoxic conditions, metformin or rotenone elevated the rate and the amplitude of Ca2+ signals 10-15 min after drug application. Addition of cyclosporin A, a blocker of mitochondrial permeability transition pore (mPTP), antioxidant trolox, or inositol 1,4,5-trisphosphate receptor (IP3R) blocker caffeine in the presence of rotenone reduced the elevated rate and the amplitude of the signals implying sensitivity to reactive oxygen species (ROS), and involvement of mitochondrial mPTP together with IP3R. Microglial cells exposed to mild hypoxic conditions for 24 h showed elevated rate and increased amplitude of Ca2+ signals. Application of metformin or rotenone but not phenformin before mild hypoxia reduced this elevated rate. Thus, metformin and rotenone had the opposing fast action in normoxia after 10-15 min and the slow action during 24 h mild-hypoxia implying activation of different signaling pathways. The slow action of metformin through inhibition of complex I could stabilize Ca2+ homeostasis after mild hypoxia and could be important for reduction of ischemia-induced microglial activation.
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Grahl MVC, Uberti AF, Broll V, Bacaicoa-Caruso P, Meirelles EF, Carlini CR. Proteus mirabilis Urease: Unsuspected Non-Enzymatic Properties Relevant to Pathogenicity. Int J Mol Sci 2021; 22:ijms22137205. [PMID: 34281258 PMCID: PMC8268090 DOI: 10.3390/ijms22137205] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 06/25/2021] [Accepted: 06/29/2021] [Indexed: 12/22/2022] Open
Abstract
Infection by Proteus mirabilis causes urinary stones and catheter incrustation due to ammonia formed by urease (PMU), one of its virulence factors. Non-enzymatic properties, such as pro-inflammatory and neurotoxic activities, were previously reported for distinct ureases, including that of the gastric pathogen Helicobacter pylori. Here, PMU was assayed on isolated cells to evaluate its non-enzymatic properties. Purified PMU (nanomolar range) was tested in human (platelets, HEK293 and SH-SY5Y) cells, and in murine microglia (BV-2). PMU promoted platelet aggregation. It did not affect cellular viability and no ammonia was detected in the cultures’ supernatants. PMU-treated HEK293 cells acquired a pro-inflammatory phenotype, producing reactive oxygen species (ROS) and cytokines IL-1β and TNF-α. SH-SY5Y cells stimulated with PMU showed high levels of intracellular Ca2+ and ROS production, but unlike BV-2 cells, SH-SY5Y did not synthesize TNF-α and IL-1β. Texas Red-labeled PMU was found in the cytoplasm and in the nucleus of all cell types. Bioinformatic analysis revealed two bipartite nuclear localization sequences in PMU. We have shown that PMU, besides urinary stone formation, can potentially contribute in other ways to pathogenesis. Our data suggest that PMU triggers pro-inflammatory effects and may affect cells beyond the renal system, indicating a possible role in extra-urinary diseases.
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Affiliation(s)
- Matheus V. C. Grahl
- Laboratory of Neurotoxins, Brain Institute of Rio Grande do Sul (BRAINS) and Graduate Program in Medicine and Health Sciences, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre CEP 90610-000, RS, Brazil; (M.V.C.G.); (A.F.U.)
| | - Augusto F. Uberti
- Laboratory of Neurotoxins, Brain Institute of Rio Grande do Sul (BRAINS) and Graduate Program in Medicine and Health Sciences, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre CEP 90610-000, RS, Brazil; (M.V.C.G.); (A.F.U.)
| | - Valquiria Broll
- Graduate Program in Cellular and Molecular Biology, Center of Biotechnology, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre CEP 91501-970, RS, Brazil;
| | - Paula Bacaicoa-Caruso
- Laboratory of Neurotoxins, Brain Institute of Rio Grande do Sul (BRAINS) and Graduate Program in Cellular and Molecular Biology, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre CEP 90610-000, RS, Brazil;
| | - Evelin F. Meirelles
- Laboratory of Neurotoxins, Brain Institute of Rio Grande do Sul (BRAINS), Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre CEP 90610-000, RS, Brazil;
| | - Celia R. Carlini
- Laboratory of Neurotoxins, Brain Institute of Rio Grande do Sul (BRAINS) and School of Medicine, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre CEP 90610-000, RS, Brazil
- Correspondence: ; Tel.: +55-51-33205986
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29
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Li X, Wu X, Li N, Li D, Sui A, Khan K, Ge B, Li S, Li S, Zhao J. Scorpion venom heat-resistant synthesized peptide ameliorates 6-OHDA-induced neurotoxicity and neuroinflammation: likely role of Na v 1.6 inhibition in microglia. Br J Pharmacol 2021; 178:3553-3569. [PMID: 33886140 DOI: 10.1111/bph.15502] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 02/26/2021] [Accepted: 03/23/2021] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND AND PURPOSE Microglia-related inflammation is associated with the pathology of Parkinson's disease. Functional voltage-gated sodium channels (VGSCs) are involved in regulating microglial function. Here, we aim to investigate the effects of scorpion venom heat-resistant synthesized peptide (SVHRSP) on 6-hydroxydopamine (6-OHDA)-induced Parkinson's disease-like mouse model and reveal its underlying mechanism. EXPERIMENTAL APPROACH Unilateral brain injection of 6-OHDA was performed to establish Parkinson's disease mouse model. After behaviour test, brain tissues were collected for morphological analysis and protein/gene expression examination. Primary microglia culture was used to investigate the role of sodium channel Nav 1.6 in the regulation of microglia inflammation by SVHRSP. KEY RESULTS SVHRSP treatment attenuated motor deficits, dopamine neuron degeneration, activation of glial cells and expression of pro-inflammatory cytokines induced by 6-OHDA lesion. Primary microglia activation and the production of pro-inflammatory cytokines induced by lipopolysaccharide (LPS) were also suppressed by SVHRSP treatment. In addition, SVHRSP could inhibit mitogen-activated protein kinases (MAPKs) pathway, which plays pivotal roles in the pro-inflammatory response. Notably, SVHRSP treatment suppressed the overexpression of microglial Nav 1.6 induced by 6-OHDA and LPS. Finally, it was shown that the anti-inflammatory effect of SVHRSP in microglia was Nav 1.6 dependent and was related to suppression of sodium current and probably the consequent Na+ /Ca2+ exchange. CONCLUSIONS AND IMPLICATIONS SVHRSP might inhibit neuroinflammation and protect dopamine neurons via down-regulating microglial Nav 1.6 and subsequently suppressing intracellular Ca2+ accumulation to attenuate the activation of MAPKs signalling pathway in microglia.
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Affiliation(s)
- Xiujie Li
- National-Local Joint Engineering Research Center for Drug Research and Development (R&D) of Neurodegenerative Diseases, Dalian Medical University, Dalian, China
| | - Xuefei Wu
- Liaoning Provincial Key Laboratory of Cerebral Diseases, Department of Physiology, College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Na Li
- National-Local Joint Engineering Research Center for Drug Research and Development (R&D) of Neurodegenerative Diseases, Dalian Medical University, Dalian, China
| | - Donglai Li
- National-Local Joint Engineering Research Center for Drug Research and Development (R&D) of Neurodegenerative Diseases, Dalian Medical University, Dalian, China
| | - Aoran Sui
- Liaoning Provincial Key Laboratory of Cerebral Diseases, Department of Physiology, College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Khizar Khan
- Liaoning Provincial Key Laboratory of Cerebral Diseases, Department of Physiology, College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Biying Ge
- National-Local Joint Engineering Research Center for Drug Research and Development (R&D) of Neurodegenerative Diseases, Dalian Medical University, Dalian, China
| | - Sheng Li
- National-Local Joint Engineering Research Center for Drug Research and Development (R&D) of Neurodegenerative Diseases, Dalian Medical University, Dalian, China
| | - Shao Li
- National-Local Joint Engineering Research Center for Drug Research and Development (R&D) of Neurodegenerative Diseases, Dalian Medical University, Dalian, China.,Liaoning Provincial Key Laboratory of Cerebral Diseases, Department of Physiology, College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Jie Zhao
- National-Local Joint Engineering Research Center for Drug Research and Development (R&D) of Neurodegenerative Diseases, Dalian Medical University, Dalian, China
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Morris G, Walder K, Kloiber S, Amminger P, Berk M, Bortolasci CC, Maes M, Puri BK, Carvalho AF. The endocannabinoidome in neuropsychiatry: Opportunities and potential risks. Pharmacol Res 2021; 170:105729. [PMID: 34119623 DOI: 10.1016/j.phrs.2021.105729] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 05/31/2021] [Accepted: 06/09/2021] [Indexed: 02/08/2023]
Abstract
The endocannabinoid system (ECS) comprises two cognate endocannabinoid receptors referred to as CB1R and CB2R. ECS dysregulation is apparent in neurodegenerative/neuro-psychiatric disorders including but not limited to schizophrenia, major depressive disorder and potentially bipolar disorder. The aim of this paper is to review mechanisms whereby both receptors may interact with neuro-immune and neuro-oxidative pathways, which play a pathophysiological role in these disorders. CB1R is located in the presynaptic terminals of GABAergic, glutamatergic, cholinergic, noradrenergic and serotonergic neurons where it regulates the retrograde suppression of neurotransmission. CB1R plays a key role in long-term depression, and, to a lesser extent, long-term potentiation, thereby modulating synaptic transmission and mediating learning and memory. Optimal CB1R activity plays an essential neuroprotective role by providing a defense against the development of glutamate-mediated excitotoxicity, which is achieved, at least in part, by impeding AMPA-mediated increase in intracellular calcium overload and oxidative stress. Moreover, CB1R activity enables optimal neuron-glial communication and the function of the neurovascular unit. CB2R receptors are detected in peripheral immune cells and also in central nervous system regions including the striatum, basal ganglia, frontal cortex, hippocampus, amygdala as well as the ventral tegmental area. CB2R upregulation inhibits the presynaptic release of glutamate in several brain regions. CB2R activation also decreases neuroinflammation partly by mediating the transition from a predominantly neurotoxic "M1" microglial phenotype to a more neuroprotective "M2" phenotype. CB1R and CB2R are thus novel drug targets for the treatment of neuro-immune and neuro-oxidative disorders including schizophrenia and affective disorders.
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Affiliation(s)
- Gerwyn Morris
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia
| | - Ken Walder
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia; Deakin University, Centre for Molecular and Medical Research, School of Medicine, Geelong, Australia
| | - Stefan Kloiber
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, 33 Ursula Franklin Street, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Paul Amminger
- Orygen, Parkville, Victoria, Australia; Centre for Youth Mental Health, The University of Melbourne, Parkville, Victoria, Australia
| | - Michael Berk
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia; Orygen, The National Centre of Excellence in Youth Mental Health, Centre for Youth Mental Health, Florey Institute for Neuroscience and Mental Health and the Department of Psychiatry, The University of Melbourne, Melbourne, Australia
| | - Chiara C Bortolasci
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia
| | - Michael Maes
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia; Department of Psychiatry, Faculty of Medicine, King Chulalongkorn Memorial Hospital, Bangkok, Thailand; Department of Psychiatry, Medical University of Plovdiv, Plovdiv, Bulgaria
| | | | - Andre F Carvalho
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia.
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Redmon SN, Yarishkin O, Lakk M, Jo A, Mustafic E, Tvrdik P, Križaj D. TRPV4 channels mediate the mechanoresponse in retinal microglia. Glia 2021; 69:1563-1582. [PMID: 33624376 PMCID: PMC8989051 DOI: 10.1002/glia.23979] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 02/02/2021] [Accepted: 02/02/2021] [Indexed: 12/12/2022]
Abstract
The physiological and neurological correlates of plummeting brain osmolality during edema, traumatic CNS injury, and severe ischemia are compounded by neuroinflammation. Using multiple approaches, we investigated how retinal microglia respond to challenges mediated by increases in strain, osmotic gradients, and agonists of the stretch-activated cation channel TRPV4. Dissociated and intact microglia were TRPV4-immunoreactive and responded to the selective agonist GSK1016790A and substrate stretch with altered motility and elevations in intracellular calcium ([Ca2+ ]i ). Agonist- and hypotonicity-induced swelling was associated with a nonselective outwardly rectifying cation current, increased [Ca2+ ]i , and retraction of higher-order processes. The antagonist HC067047 reduced the extent of hypotonicity-induced microglial swelling and inhibited the suppressive effects of GSK1016790A and hypotonicity on microglial branching. Microglial TRPV4 signaling required intermediary activation of phospholipase A2 (PLA2), cytochrome P450, and epoxyeicosatrienoic acid production (EETs). The expression pattern of vanilloid thermoTrp genes in retinal microglia was markedly different from retinal neurons, astrocytes, and cortical microglia. These results suggest that TRPV4 represents a primary retinal microglial sensor of osmochallenges under physiological and pathological conditions. Its activation, associated with PLA2, modulates calcium signaling and cell architecture. TRPV4 inhibition might be a useful strategy to suppress microglial overactivation in the swollen and edematous CNS.
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Affiliation(s)
- Sarah N. Redmon
- Department of Ophthalmology & Visual Sciences, Moran Eye Institute, Salt Lake City, UT 84132
| | - Oleg Yarishkin
- Department of Ophthalmology & Visual Sciences, Moran Eye Institute, Salt Lake City, UT 84132
| | - Monika Lakk
- Department of Ophthalmology & Visual Sciences, Moran Eye Institute, Salt Lake City, UT 84132
| | - Andrew Jo
- Department of Ophthalmology & Visual Sciences, Moran Eye Institute, Salt Lake City, UT 84132
| | - Edin Mustafic
- Department of Ophthalmology & Visual Sciences, Moran Eye Institute, Salt Lake City, UT 84132
| | - Peter Tvrdik
- Department of Neurological Surgery, University of Virginia School of Medicine, Charlottesville VA 22908
| | - David Križaj
- Department of Ophthalmology & Visual Sciences, Moran Eye Institute, Salt Lake City, UT 84132
- Interdepartmental Program in Neuroscience, University of Utah, Salt Lake City, UT 84132
- Department of Bioengineering, University of Utah, Salt Lake City, UT 84132
- Department of Neurobiology & Anatomy, University of Utah, Salt Lake City, UT 84132
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32
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Yi MH, Liu YU, Umpierre AD, Chen T, Ying Y, Zheng J, Dheer A, Bosco DB, Dong H, Wu LJ. Optogenetic activation of spinal microglia triggers chronic pain in mice. PLoS Biol 2021; 19:e3001154. [PMID: 33739978 PMCID: PMC8011727 DOI: 10.1371/journal.pbio.3001154] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 03/31/2021] [Accepted: 02/24/2021] [Indexed: 12/30/2022] Open
Abstract
Spinal microglia are highly responsive to peripheral nerve injury and are known to be a key player in pain. However, there has not been direct evidence showing that selective microglial activation in vivo is sufficient to induce chronic pain. Here, we used optogenetic approaches in microglia to address this question employing CX3CR1creER/+: R26LSL-ReaChR/+ transgenic mice, in which red-activated channelrhodopsin (ReaChR) is inducibly and specifically expressed in microglia. We found that activation of ReaChR by red light in spinal microglia evoked reliable inward currents and membrane depolarization. In vivo optogenetic activation of microglial ReaChR in the spinal cord triggered chronic pain hypersensitivity in both male and female mice. In addition, activation of microglial ReaChR up-regulated neuronal c-Fos expression and enhanced C-fiber responses. Mechanistically, ReaChR activation led to a reactive microglial phenotype with increased interleukin (IL)-1β production, which is likely mediated by inflammasome activation and calcium elevation. IL-1 receptor antagonist (IL-1ra) was able to reverse the pain hypersensitivity and neuronal hyperactivity induced by microglial ReaChR activation. Therefore, our work demonstrates that optogenetic activation of spinal microglia is sufficient to trigger chronic pain phenotypes by increasing neuronal activity via IL-1 signaling.
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Affiliation(s)
- Min-Hee Yi
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Yong U. Liu
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Anthony D. Umpierre
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Tingjun Chen
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Yanlu Ying
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Jiaying Zheng
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Aastha Dheer
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Dale B. Bosco
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Hailong Dong
- Department of Anesthesiology & Perioperative Medicine, Xijing Hospital, Fourth Military Medical University, Xi’an, China
| | - Long-Jun Wu
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, United States of America
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, United States of America
- Department of Immunology, Mayo Clinic, Rochester, Minnesota, United States of America
- * E-mail:
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Microglial Calcium: An Exquisite Sensor for Neuronal Activity. Neurosci Bull 2021; 37:582-584. [PMID: 33738755 DOI: 10.1007/s12264-021-00655-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 08/21/2020] [Indexed: 10/21/2022] Open
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Li T, Chu X, Xin D, Ke H, Wang S, Liu D, Chen W, Wang Z. H 2S prevents peripheral immune cell invasion, increasing [Ca 2+]i and excessive phagocytosis following hypoxia-ischemia injury in neonatal mice. Biomed Pharmacother 2021; 135:111207. [PMID: 33460958 DOI: 10.1016/j.biopha.2020.111207] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 12/15/2020] [Accepted: 12/26/2020] [Indexed: 12/24/2022] Open
Abstract
We previously reported that L-Cysteine, H2S donor, remarkably attenuated neuroinflammation following hypoxia-ischemia (HI) brain injury in neonatal mice. However, its anti-inflammatory mechanism for HI insult is still unknown. The study focus on the effects of L-Cysteine on immune cell populations, Ca2+ mobilization and phagocytosis after neonatal HI. We found that L-Cysteine treatment skewed CD11b+/CD45low microglia and CD11b+/CD45high brain monocytes/macrophages towards a more anti-inflammatory property 72 h after HI-injured brain. Moreover, L-Cysteine treatment reduced cerebral infiltration of CD4 T cells 7 days following HI insult. Furthermore, CD4 T cell subset analysis revealed that L-Cysteine treatment decreased Th1 and Th2 counts, while increased Th17/Th2 ratio. Moreover, L-Cysteine treatment suppressed LPS-induced cytosolic Ca2+ and LPS-stimulated phagocytosis in primary microglia. The anti-inflammatory effect of L-Cysteine was associated with improving neurobehavioral impairment following HI insult. Our results demonstrate L-Cysteine treatment suppressed the invasion of peripheral immune cells, increasing [Ca2+]i and excessive phagocytosis to improve neurobehavioral deficits following hypoxia-ischemia injury in neonatal mice by H2S release.
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Affiliation(s)
- Tingting Li
- Department of Physiology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, 250012, PR China
| | - Xili Chu
- Department of Physiology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, 250012, PR China
| | - Danqing Xin
- Department of Physiology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, 250012, PR China
| | - Hongfei Ke
- Department of Physiology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, 250012, PR China; Department of Medical Psychology and Ethics, School of Basic Medicine Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, PR China
| | - Shuhan Wang
- Department of Physiology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, 250012, PR China
| | - Dexiang Liu
- Department of Medical Psychology and Ethics, School of Basic Medicine Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, PR China
| | - Wenqiang Chen
- Qilu Hospital, Shandong University, Jinan, Shandong, PR China
| | - Zhen Wang
- Department of Physiology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, 250012, PR China.
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Maksoud MJE, Tellios V, Xiang YY, Lu WY. Nitric oxide displays a biphasic effect on calcium dynamics in microglia. Nitric Oxide 2021; 108:28-39. [PMID: 33418057 DOI: 10.1016/j.niox.2021.01.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 11/11/2020] [Accepted: 01/01/2021] [Indexed: 01/13/2023]
Abstract
Calcium is a critical secondary messenger in microglia. In response to inflammation, microglia mobilize intracellular calcium and increase the expression of inducible nitric oxide synthase (iNOS), which produces nitric oxide (NO). This study set to explore whether NO regulates intracellular calcium dynamics through transient receptor potential (TRP) channels in primary wildtype (WT) and iNOS knockout (iNOS-/-) microglia, and the BV2 microglial cell line using calcium imaging and voltage-clamp recordings. Our results demonstrated that application of the NO-donor SNAP induced a biphasic calcium response in naïve murine microglia. Specifically, phase I was characterized by a rapid decline in calcium influx that was attenuated by pretreatment of the store operated calcium channel (SOCC) inhibitor 2APB, while phase II presented as a slow calcium influx that was abolished by pretreatment with the TRP vanilloid type 2 (TRPV2) channel inhibitor tranilast. Importantly, in the presence of a protein kinase G (PKG) inhibitor, the SNAP-mediated calcium decline in phase I persisted while the calcium influx in phase II was abolished. Application of thapsigargin to activate SOCCs caused a calcium influx through a nonselective cation conductance in BV2 microglia, which was abruptly attenuated by SNAP. Importantly, iNOS-/- microglia displayed a significantly larger calcium influx though SOCCs while expressing less stromal interaction molecule 1, Orai1, and TRP canonical type 1 and 3 mRNA, when compared to WT microglia. Together, these results demonstrate that NO signaling restricts calcium influx through SOCCs independent of PKG signaling and increases calcium influx through TRPV2 channels in a PKG-dependent mechanism in microglia.
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Affiliation(s)
- Matthew J E Maksoud
- Graduate Program of Neuroscience, The University of Western Ontario, Canada; Robarts Research Institute, The University of Western Ontario, Canada.
| | - Vasiliki Tellios
- Graduate Program of Neuroscience, The University of Western Ontario, Canada; Robarts Research Institute, The University of Western Ontario, Canada.
| | - Yun-Yan Xiang
- Robarts Research Institute, The University of Western Ontario, Canada.
| | - Wei-Yang Lu
- Graduate Program of Neuroscience, The University of Western Ontario, Canada; Robarts Research Institute, The University of Western Ontario, Canada; Department of Physiology and Pharmacology, University of Western Ontario, Canada.
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36
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The aging mouse brain: cognition, connectivity and calcium. Cell Calcium 2021; 94:102358. [PMID: 33517250 DOI: 10.1016/j.ceca.2021.102358] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 01/16/2021] [Accepted: 01/18/2021] [Indexed: 02/08/2023]
Abstract
Aging is a complex process that differentially impacts multiple cognitive, sensory, neuronal and molecular processes. Technological innovations now allow for parallel investigation of neuronal circuit function, structure and molecular composition in the brain of awake behaving adult mice. Thus, mice have become a critical tool to better understand how aging impacts the brain. However, a more granular systems-based approach, which considers the impact of age on key features relating to neural processing, is required. Here, we review evidence probing the impact of age on the mouse brain. We focus on a range of processes relating to neuronal function, including cognitive abilities, sensory systems, synaptic plasticity and calcium regulation. Across many systems, we find evidence for prominent age-related dysregulation even before 12 months of age, suggesting that emerging age-related alterations can manifest by late adulthood. However, we also find reports suggesting that some processes are remarkably resilient to aging. The evidence suggests that aging does not drive a parallel, linear dysregulation of all systems, but instead impacts some processes earlier, and more severely, than others. We propose that capturing the more fine-scale emerging features of age-related vulnerability and resilience may provide better opportunities for the rejuvenation of the aged brain.
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37
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Umpierre AD, Wu LJ. How microglia sense and regulate neuronal activity. Glia 2020; 69:1637-1653. [PMID: 33369790 DOI: 10.1002/glia.23961] [Citation(s) in RCA: 100] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 12/17/2020] [Accepted: 12/18/2020] [Indexed: 12/16/2022]
Abstract
Microglia are innate immune cells of the central nervous system that sense extracellular cues. Brain injuries, inflammation, and pathology evoke dynamic structural responses in microglia, altering their morphology and motility. The dynamic motility of microglia is hypothesized to be a critical first step in sensing local alterations and engaging in pattern-specific responses. Alongside their pathological responses, microglia also sense and regulate neuronal activity. In this review, we consider the extracellular molecules, receptors, and mechanisms that allow microglia to sense neuronal activity changes under both hypoactivity and hyperactivity. We also highlight emerging in vivo evidence that microglia regulate neuronal activity, ranging from physiological to pathophysiological conditions. In addition, we discuss the emerging role of calcium signaling in microglial responses to the extracellular environment. The dynamic function of microglia in monitoring and influencing neuronal activity may be critical for brain homeostasis and circuit modification in health and disease.
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Affiliation(s)
| | - Long-Jun Wu
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA.,Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, USA.,Department of Immunology, Mayo Clinic, Rochester, Minnesota, USA
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38
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Liu L, Kearns KN, Eli I, Sharifi KA, Soldozy S, Carlson EW, Scott KW, Sluzewski MF, Acton ST, Stauderman KA, Kalani MYS, Park M, Tvrdik P. Microglial Calcium Waves During the Hyperacute Phase of Ischemic Stroke. Stroke 2020; 52:274-283. [PMID: 33161850 DOI: 10.1161/strokeaha.120.032766] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
BACKGROUND AND PURPOSE Ischemic injury triggers multiple pathological responses in the brain tissue, including spreading depolarizations across the cerebral cortex (cortical spreading depolarizations [CSD]). Microglia have been recently shown to play a significant role in the propagation of CSD. However, the intracellular responses of myeloid cells during ischemic stroke have not been investigated. METHODS We have studied intracellular calcium activity in cortical microglia in the stroke model of the middle cerebral artery occlusion, using the murine Polr2a-based and Cre-dependent GCaMP5 and tdTomato reporter (PC::G5-tdT). High-speed 2-photon microscopy through cranial windows was employed to record signals from genetically encoded indicators of calcium. Inflammatory stimuli and pharmacological inhibition were used to modulate microglial calcium responses in the somatosensory cortex. RESULTS In vivo imaging revealed periodical calcium activity in microglia during the hyperacute phase of ischemic stroke. This activity was more frequent during the first 6 hours after occlusion, but the amplitudes of calcium transients became larger at later time points. Consistent with CSD nature of these events, we reproducibly triggered comparable calcium transients with microinjections of potassium chloride (KCl) into adjacent cortical areas. Furthermore, lipopolysaccharide-induced peripheral inflammation, mimicking sterile inflammation during ischemic stroke, produced significantly greater microglial calcium transients during CSD. Finally, in vivo pharmacological analysis with CRAC (calcium release-activated channel) inhibitor CM-EX-137 demonstrated that CSD-associated microglial calcium transients after KCl microinjections are mediated at least in part by the CRAC mechanism. CONCLUSIONS Our findings demonstrate that microglia participate in ischemic brain injury via previously undetected mechanisms, which may provide new avenues for therapeutic interventions.
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Affiliation(s)
- Lei Liu
- Department of Neurological Surgery (L.L., K.N.K., K.A. Sharifi, S.S., K.W.S., M.Y.S.K., M.P., P.T.), University of Virginia Health System, Charlottesville
| | - Kathryn N Kearns
- Department of Neurological Surgery (L.L., K.N.K., K.A. Sharifi, S.S., K.W.S., M.Y.S.K., M.P., P.T.), University of Virginia Health System, Charlottesville
| | - Ilyas Eli
- Department of Neurosurgery (I.E., E.W.C.), University of Utah School of Medicine, Salt Lake City
| | - Khadijeh A Sharifi
- Department of Neurological Surgery (L.L., K.N.K., K.A. Sharifi, S.S., K.W.S., M.Y.S.K., M.P., P.T.), University of Virginia Health System, Charlottesville
- Department of Neuroscience (K.A. Sharifi, M.Y.S.K., P.T.), University of Virginia Health System, Charlottesville
| | - Sauson Soldozy
- Department of Neurological Surgery (L.L., K.N.K., K.A. Sharifi, S.S., K.W.S., M.Y.S.K., M.P., P.T.), University of Virginia Health System, Charlottesville
| | - Elizabeth W Carlson
- Department of Neurosurgery (I.E., E.W.C.), University of Utah School of Medicine, Salt Lake City
| | - Kyle W Scott
- Department of Neurological Surgery (L.L., K.N.K., K.A. Sharifi, S.S., K.W.S., M.Y.S.K., M.P., P.T.), University of Virginia Health System, Charlottesville
| | - M Filip Sluzewski
- Department of Electrical and Computer Engineering (M.F.S., S.T.A.), University of Virginia Health System, Charlottesville
| | - Scott T Acton
- Department of Electrical and Computer Engineering (M.F.S., S.T.A.), University of Virginia Health System, Charlottesville
| | | | - M Yashar S Kalani
- Department of Neurological Surgery (L.L., K.N.K., K.A. Sharifi, S.S., K.W.S., M.Y.S.K., M.P., P.T.), University of Virginia Health System, Charlottesville
- Department of Neuroscience (K.A. Sharifi, M.Y.S.K., P.T.), University of Virginia Health System, Charlottesville
| | - Min Park
- Department of Neurological Surgery (L.L., K.N.K., K.A. Sharifi, S.S., K.W.S., M.Y.S.K., M.P., P.T.), University of Virginia Health System, Charlottesville
| | - Petr Tvrdik
- Department of Neurological Surgery (L.L., K.N.K., K.A. Sharifi, S.S., K.W.S., M.Y.S.K., M.P., P.T.), University of Virginia Health System, Charlottesville
- Department of Neuroscience (K.A. Sharifi, M.Y.S.K., P.T.), University of Virginia Health System, Charlottesville
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Huang CT, Chen SH, Chang CF, Lin SC, Lue JH, Tsai YJ. Melatonin reduces neuropathic pain behavior and glial activation through MT 2 melatonin receptor modulation in a rat model of lysophosphatidylcholine-induced demyelination neuropathy. Neurochem Int 2020; 140:104827. [PMID: 32853748 DOI: 10.1016/j.neuint.2020.104827] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Revised: 07/28/2020] [Accepted: 08/07/2020] [Indexed: 12/17/2022]
Abstract
In this study, we investigated whether melatonin treatment prevents development of neuropathic pain via suppression of glial mitogen-activated protein kinases (MAPKs) activation in the cuneate nucleus (CN) in a lysophosphatidylcholine (LPC)-induced median nerve demyelination neuropathy model. Rats were fed orally with melatonin once a day at a dose of 37.5, 75, or 150 mg/kg 30 min before until 3 days after LPC treatment. Subsequently, behavioral tests were conducted on these animals, and immunohistochemistry and immunoblotting were used for qualitative and quantitative analysis of glia and MAPKs, including ERK, JNK, and p38, activation. Enzyme-linked immunosorbent assays were applied to measure pro-inflammatory cytokine responses. Furthermore, intra-CN microinjection of S26131 (MT1 receptor antagonist), 4P-PDOT (MT2 receptor antagonist), or prazosin (MT3 receptor antagonist) were performed to investigate the association between melatonin receptor subtypes and effects of melatonin on demyelination neuropathy. LPC treatment of the median nerve induced a significant increase in glial fibrillary acidic protein (GFAP; an astrocyte marker) and ED1 (an activated microglia marker) immunoreactivity in the ipsilateral CN and led to development of neuropathic pain behavior. Inspection of GFAP-immunoreactive astrocytes revealed that astrocytic hypertrophy, but not proliferation, contributed to increased GFAP immunoreactivity. Double immunofluorescence showed that both GFAP-immunoreactive astrocytes and ED1-immunoreactive microglia co-expressed p-ERK, p-JNK, and p-p38 immunoreactivity. Melatonin administration dose-dependently reduced neuropathic pain behavior, decreased glial and MAPKs activation, and diminished the release of pro-inflammatory cytokines in the ipsilateral CN after LPC treatment. Furthermore, 4P-PDOT, but not S26131 or prazosin, antagonized the therapeutic effects of melatonin. In conclusion, administration of melatonin, via its cognate MT2 receptor, inhibited activation of glial MAPKs, production of pro-inflammatory cytokines, and development of demyelination-induced neuropathic pain behavior.
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Affiliation(s)
- Chun-Ta Huang
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan; Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Seu-Hwa Chen
- Department of Anatomy, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Chi-Fen Chang
- Department of Anatomy, School of Medicine, China Medical University, Taichung, Taiwan
| | - Shih-Chang Lin
- Division of Allergy and Immunology, Department of Internal Medicine, Cathay General Hospital, Taipei, Taiwan
| | - June-Horng Lue
- Department of Anatomy and Cell Biology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Yi-Ju Tsai
- Graduate Institute of Biomedical and Pharmaceutical Science, College of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan.
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Altered serum protein levels in frontotemporal dementia and amyotrophic lateral sclerosis indicate calcium and immunity dysregulation. Sci Rep 2020; 10:13741. [PMID: 32792518 PMCID: PMC7426269 DOI: 10.1038/s41598-020-70687-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 08/03/2020] [Indexed: 12/11/2022] Open
Abstract
Frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) are neurodegenerative diseases that are considered to be on the same disease spectrum because of overlapping genetic, pathological and clinical traits. Changes in serum proteins in FTD and ALS are poorly understood, and currently no definitive biomarkers exist for diagnosing or monitoring disease progression for either disease. Here we applied quantitative discovery proteomics to analyze protein changes in FTD (N = 72) and ALS (N = 28) patient serum compared to controls (N = 22). Twenty three proteins were significantly altered in FTD compared to controls (increased-APOL1, C3, CTSH, EIF5A, MYH2, S100A8, SUSD5, WDR1; decreased-C1S, C7, CILP2, COMP, CRTAC1, EFEMP1, FBLN1, GSN, HSPG2, IGHV1, ITIH2, PROS1, SHBG, UMOD, VASN) and 14 proteins were significantly altered in ALS compared to controls (increased-APOL1, CKM, CTSH, IGHG1, IGKC, MYH2; decreased-C7, COMP, CRTAC1, EFEMP1, FBLN1, GSN, HSPG2, SHBG). There was substantial overlap in the proteins that were altered in FTD and ALS. These results were validated using western blotting. Gene ontology tools were used to assess functional pathways potentially dysregulated in the two diseases, and calcium ion binding and innate immunity pathways were altered in both diseases. When put together, these results suggest significant overlap in pathophysiological peripheral changes in FTD and ALS. This study represents the first proteomics side-by-side comparison of serum changes in FTD and ALS, providing new insights into under-recognized perturbed pathways and an avenue for biomarker development for FTD and ALS.
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41
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Umpierre AD, Bystrom LL, Ying Y, Liu YU, Worrell G, Wu LJ. Microglial calcium signaling is attuned to neuronal activity in awake mice. eLife 2020; 9:56502. [PMID: 32716294 PMCID: PMC7402678 DOI: 10.7554/elife.56502] [Citation(s) in RCA: 102] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Accepted: 07/14/2020] [Indexed: 12/14/2022] Open
Abstract
Microglial calcium signaling underlies a number of key physiological and pathological processes in situ, but has not been studied in vivo in awake mice. Using multiple GCaMP6 variants targeted to microglia, we assessed how microglial calcium signaling responds to alterations in neuronal activity across a wide range. We find that only a small subset of microglial somata and processes exhibited spontaneous calcium transients in a chronic window preparation. However, hyperactive shifts in neuronal activity (kainate status epilepticus and CaMKIIa Gq DREADD activation) triggered increased microglial process calcium signaling, often concomitant with process extension. Additionally, hypoactive shifts in neuronal activity (isoflurane anesthesia and CaMKIIa Gi DREADD activation) also increased microglial process calcium signaling. Under hypoactive neuronal conditions, microglia also exhibited process extension and outgrowth with greater calcium signaling. Our work reveals that microglia have highly distinct microdomain signaling, and that processes specifically respond to bi-directional shifts in neuronal activity through increased calcium signaling.
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Affiliation(s)
| | | | - Yanlu Ying
- Department of Neurology, Mayo Clinic, Rochester, United States
| | - Yong U Liu
- Department of Neurology, Mayo Clinic, Rochester, United States
| | - Gregory Worrell
- Department of Neurology, Mayo Clinic, Rochester, United States
| | - Long-Jun Wu
- Department of Neurology, Mayo Clinic, Rochester, United States.,Department of Neuroscience, Mayo Clinic, Jacksonville, United States.,Department of Immunology, Mayo Clinic, Rochester, United States
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Venkateswarlu K, Suman G, Dhyani V, Swain S, Giri L, Samavedi S. Three‐dimensional imaging and quantification of real‐time cytosolic calcium oscillations in microglial cells cultured on electrospun matrices using laser scanning confocal microscopy. Biotechnol Bioeng 2020; 117:3108-3123. [DOI: 10.1002/bit.27465] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Revised: 05/24/2020] [Accepted: 06/16/2020] [Indexed: 12/28/2022]
Affiliation(s)
- Kojja Venkateswarlu
- Department of Chemical Engineering Indian Institute of Technology Hyderabad Sangareddy Telangana India
| | - Gare Suman
- Department of Chemical Engineering Indian Institute of Technology Hyderabad Sangareddy Telangana India
| | - Vaibhav Dhyani
- Department of Chemical Engineering Indian Institute of Technology Hyderabad Sangareddy Telangana India
| | - Sarpras Swain
- Department of Chemical Engineering Indian Institute of Technology Hyderabad Sangareddy Telangana India
| | - Lopamudra Giri
- Department of Chemical Engineering Indian Institute of Technology Hyderabad Sangareddy Telangana India
| | - Satyavrata Samavedi
- Department of Chemical Engineering Indian Institute of Technology Hyderabad Sangareddy Telangana India
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Salas IH, Burgado J, Allen NJ. Glia: victims or villains of the aging brain? Neurobiol Dis 2020; 143:105008. [PMID: 32622920 DOI: 10.1016/j.nbd.2020.105008] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 06/14/2020] [Accepted: 06/29/2020] [Indexed: 12/11/2022] Open
Abstract
Aging is the strongest risk factor for metabolic, vascular and neurodegenerative diseases. Aging alone is associated with a gradual decline of cognitive and motor functions. Considering an increasing elderly population in the last century, understanding the cellular and molecular mechanisms contributing to brain aging is of vital importance. Recent genetic and transcriptomic findings strongly suggest that glia are the first cells changing with aging. Glial cells constitute around 50% of the total cells in the brain and play key roles regulating brain homeostasis in health and disease. Their essential functions include providing nutritional support to neurons, activation of immune responses, and regulation of synaptic transmission and plasticity. In this review we discuss how glia are altered in the aging brain and whether these alterations are protective or contribute to the age-related pathological cascade. We focus on the major morphological, transcriptional and functional changes affecting glia in a range of systems, including human, non-human primates, and rodents. We also highlight future directions for investigating the roles of glia in brain aging.
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Affiliation(s)
- Isabel H Salas
- Salk Institute for Biological Studies, Molecular Neurobiology Laboratory, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Jillybeth Burgado
- Salk Institute for Biological Studies, Molecular Neurobiology Laboratory, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Nicola J Allen
- Salk Institute for Biological Studies, Molecular Neurobiology Laboratory, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
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44
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Apamin Suppresses LPS-Induced Neuroinflammatory Responses by Regulating SK Channels and TLR4-Mediated Signaling Pathways. Int J Mol Sci 2020; 21:ijms21124319. [PMID: 32560481 PMCID: PMC7352249 DOI: 10.3390/ijms21124319] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 06/11/2020] [Accepted: 06/16/2020] [Indexed: 02/07/2023] Open
Abstract
Neuroinflammation plays a vital role in neurodegenerative conditions. Microglia are a key component of the neuroinflammatory response. There is a growing interest in developing drugs to target microglia and thereby control neuroinflammatory processes. Apamin (APM) is a specifically selective antagonist of small conductance calcium-activated potassium (SK) channels. However, its effect on neuroinflammation is largely unknown. We examine the effects of APM on lipopolysaccharide (LPS)-stimulated BV2 and rat primary microglial cells. Regarding the molecular mechanism by which APM significantly inhibits proinflammatory cytokine production and microglial cell activation, we found that APM does so by reducing the expression of phosphorylated CaMKII and toll-like receptor (TLR4). In particular, APM potently suppressed the translocation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)/signal transducer and activator of transcription (STAT)3 and phosphorylated mitogen-activated protein kinases (MAPK)-extracellular signal-regulated kinase (ERK). In addition, the correlation of NF-κB/STAT3 and MAPK-ERK in the neuroinflammatory response was verified through inhibitors. The literature and our findings suggest that APM is a promising candidate for an anti-neuroinflammatory agent and can potentially be used for the prevention and treatment of various neurological disorders.
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45
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Vay SU, Flitsch LJ, Rabenstein M, Monière H, Jakovcevski I, Andjus P, Bijelic D, Blaschke S, Walter HL, Fink GR, Schroeter M, Rueger MA. The impact of hyperpolarization-activated cyclic nucleotide-gated (HCN) and voltage-gated potassium KCNQ/Kv7 channels on primary microglia function. J Neuroinflammation 2020; 17:100. [PMID: 32248813 PMCID: PMC7132998 DOI: 10.1186/s12974-020-01779-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 03/18/2020] [Indexed: 01/03/2023] Open
Abstract
Background Microglia are essential to maintain cell homeostasis in the healthy brain and are activated after brain injury. Upon activation, microglia polarize towards different phenotypes. The course of microglia activation is complex and depends on signals in the surrounding milieu. Recently, it has been suggested that microglia respond to ion currents, as a way of regulating their activity and function. Methods and results Under the hypothesis that HCN and KCNQ/Kv7 channels impact on microglia, we studied primary rat microglia in the presence or absence of specific pharmacological blockade or RNA silencing. Primary microglia expressed the subunits HCN1-4, Kv7.2, Kv7.3, and Kv7.5. The expression of HCN2, as well as Kv7.2 and Kv7.3, varied among different microglia phenotypes. The pharmacological blockade of HCN channels by ZD7288 resulted in cell depolarization with slowly rising intracellular calcium levels, leading to enhanced survival and reduced proliferation rates of resting microglia. Furthermore, ZD7288 treatment, as well as knockdown of HCN2 RNA by small interfering RNA, resulted in an attenuation of later microglia activation—both towards the anti- and pro-inflammatory phenotype. However, HCN channel inhibition enhanced the phagocytic capacity of IL4-stimulated microglia. Blockade of Kv7/KCNQ channel by XE-991 exclusively inhibited the migratory capacity of resting microglia. Conclusion These observations suggest that the HCN current contributes to various microglia functions and impacts on the course of microglia activation, while the Kv7/KCNQ channels affect microglia migration. Characterizing the role of HCN channels in microglial functioning may offer new therapeutic approaches for targeted modulation of neuroinflammation as a hallmark of various neurological disorders.
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Affiliation(s)
- Sabine Ulrike Vay
- Department of Neurology, Faculty of Medicine and University Hospital, University Hospital of Cologne, Kerpener Strasse 62, 50924, Cologne, Germany.
| | - Lea Jessica Flitsch
- Department of Neurology, Faculty of Medicine and University Hospital, University Hospital of Cologne, Kerpener Strasse 62, 50924, Cologne, Germany
| | - Monika Rabenstein
- Department of Neurology, Faculty of Medicine and University Hospital, University Hospital of Cologne, Kerpener Strasse 62, 50924, Cologne, Germany
| | - Helena Monière
- Department of Neurology, Faculty of Medicine and University Hospital, University Hospital of Cologne, Kerpener Strasse 62, 50924, Cologne, Germany
| | - Igor Jakovcevski
- Institute for Molecular and Behavioural Neuroscience and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Pavle Andjus
- Center for Laser Microscopy-CLM, Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - Dunja Bijelic
- Center for Laser Microscopy-CLM, Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - Stefan Blaschke
- Department of Neurology, Faculty of Medicine and University Hospital, University Hospital of Cologne, Kerpener Strasse 62, 50924, Cologne, Germany.,Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Centre Juelich, Juelich, Germany
| | - Helene Luise Walter
- Department of Neurology, Faculty of Medicine and University Hospital, University Hospital of Cologne, Kerpener Strasse 62, 50924, Cologne, Germany
| | - Gereon Rudolf Fink
- Department of Neurology, Faculty of Medicine and University Hospital, University Hospital of Cologne, Kerpener Strasse 62, 50924, Cologne, Germany.,Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Centre Juelich, Juelich, Germany
| | - Michael Schroeter
- Department of Neurology, Faculty of Medicine and University Hospital, University Hospital of Cologne, Kerpener Strasse 62, 50924, Cologne, Germany.,Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Centre Juelich, Juelich, Germany
| | - Maria Adele Rueger
- Department of Neurology, Faculty of Medicine and University Hospital, University Hospital of Cologne, Kerpener Strasse 62, 50924, Cologne, Germany.,Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Centre Juelich, Juelich, Germany
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Spencer SA, Suárez-Pozos E, Escalante M, Myo YP, Fuss B. Sodium-Calcium Exchangers of the SLC8 Family in Oligodendrocytes: Functional Properties in Health and Disease. Neurochem Res 2020; 45:1287-1297. [PMID: 31927687 DOI: 10.1007/s11064-019-02949-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2019] [Revised: 12/20/2019] [Accepted: 12/23/2019] [Indexed: 12/30/2022]
Abstract
The solute carrier 8 (SLC8) family of sodium-calcium exchangers (NCXs) functions as an essential regulatory system that couples opposite fluxes of sodium and calcium ions across plasmalemmal membranes. NCXs, thereby, play key roles in maintaining an ion homeostasis that preserves cellular integrity. Hence, alterations in NCX expression and regulation have been found to lead to ionic imbalances that are often associated with intracellular calcium overload and cell death. On the other hand, intracellular calcium has been identified as a key driver for a multitude of downstream signaling events that are crucial for proper functioning of biological systems, thus highlighting the need for a tightly controlled balance. In the CNS, NCXs have been primarily characterized in the context of synaptic transmission and ischemic brain damage. However, a much broader picture is emerging. NCXs are expressed by virtually all cells of the CNS including oligodendrocytes (OLGs), the cells that generate the myelin sheath. With a growing appreciation of dynamic calcium signals in OLGs, NCXs are becoming increasingly recognized for their crucial roles in shaping OLG function under both physiological and pathophysiological conditions. In order to provide a current update, this review focuses on the importance of NCXs in cells of the OLG lineage. More specifically, it provides a brief introduction into plasmalemmal NCXs and their modes of activity, and it discusses the roles of OLG expressed NCXs in regulating CNS myelination and in contributing to CNS pathologies associated with detrimental effects on OLG lineage cells.
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Affiliation(s)
- Samantha A Spencer
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Box 980709, Richmond, VA, 23298, USA
| | - Edna Suárez-Pozos
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Box 980709, Richmond, VA, 23298, USA
| | - Miguel Escalante
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Box 980709, Richmond, VA, 23298, USA.,Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de México, Mexico
| | - Yu Par Myo
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Box 980709, Richmond, VA, 23298, USA
| | - Babette Fuss
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Box 980709, Richmond, VA, 23298, USA.
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Figarella K, Wolburg H, Garaschuk O, Duszenko M. Microglia in neuropathology caused by protozoan parasites. Biol Rev Camb Philos Soc 2019; 95:333-349. [PMID: 31682077 DOI: 10.1111/brv.12566] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 10/04/2019] [Accepted: 10/07/2019] [Indexed: 12/31/2022]
Abstract
Involvement of the central nervous system (CNS) is the most severe consequence of some parasitic infections. Protozoal infections comprise a group of diseases that together affect billions of people worldwide and, according to the World Health Organization, are responsible for more than 500000 deaths annually. They include African and American trypanosomiasis, leishmaniasis, malaria, toxoplasmosis, and amoebiasis. Mechanisms underlying invasion of the brain parenchyma by protozoa are not well understood and may depend on parasite nature: a vascular invasion route is most common. Immunosuppression favors parasite invasion into the CNS and therefore the host immune response plays a pivotal role in the development of a neuropathology in these infectious diseases. In the brain, microglia are the resident immune cells active in defense against pathogens that target the CNS. Beside their direct role in innate immunity, they also play a principal role in coordinating the trafficking and recruitment of other immune cells from the periphery to the CNS. Despite their evident involvement in the neuropathology of protozoan infections, little attention has given to microglia-parasite interactions. This review describes the most prominent features of microglial cells and protozoan parasites and summarizes the most recent information regarding the reaction of microglial cells to parasitic infections. We highlight the involvement of the periphery-brain axis and emphasize possible scenarios for microglia-parasite interactions.
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Affiliation(s)
- Katherine Figarella
- Institute of Physiology, Department of Neurophysiology, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Hartwig Wolburg
- Institute of Pathology and Neuropathology, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Olga Garaschuk
- Institute of Physiology, Department of Neurophysiology, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Michael Duszenko
- Institute of Physiology, Department of Neurophysiology, Eberhard Karls University of Tübingen, Tübingen, Germany
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48
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Calcium Signaling in Neurons and Glial Cells: Role of Cav1 channels. Neuroscience 2019; 421:95-111. [DOI: 10.1016/j.neuroscience.2019.09.041] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 09/27/2019] [Accepted: 09/30/2019] [Indexed: 11/18/2022]
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Hemonnot AL, Hua J, Ulmann L, Hirbec H. Microglia in Alzheimer Disease: Well-Known Targets and New Opportunities. Front Aging Neurosci 2019; 11:233. [PMID: 31543810 PMCID: PMC6730262 DOI: 10.3389/fnagi.2019.00233] [Citation(s) in RCA: 187] [Impact Index Per Article: 37.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Accepted: 08/14/2019] [Indexed: 12/21/2022] Open
Abstract
Microglia are the resident macrophages of the central nervous system. They play key roles in brain development, and physiology during life and aging. Equipped with a variety of molecular sensors and through the various functions they can fulfill, they are critically involved in maintaining the brain’s homeostasis. In Alzheimer disease (AD), microglia reaction was initially thought to be incidental and triggered by amyloid deposits and dystrophic neurites. However, recent genome-wide association studies have established that the majority of AD risk loci are found in or near genes that are highly and sometimes uniquely expressed in microglia. This leads to the concept of microglia being critically involved in the early steps of the disease and identified them as important potential therapeutic targets. Whether microglia reaction is beneficial, detrimental or both to AD progression is still unclear and the subject of intense debate. In this review, we are presenting a state-of-knowledge report intended to highlight the variety of microglial functions and pathways shown to be critically involved in AD progression. We first address both the acquisition of new functions and the alteration of their homeostatic roles by reactive microglia. Second, we propose a summary of new important parameters currently emerging in the field that need to be considered to identify relevant microglial targets. Finally, we discuss the many obstacles in designing efficient therapeutic strategies for AD and present innovative technologies that may foster our understanding of microglia roles in the pathology. Ultimately, this work aims to fly over various microglial functions to make a general and reliable report of the current knowledge regarding microglia’s involvement in AD and of the new research opportunities in the field.
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Affiliation(s)
- Anne-Laure Hemonnot
- Institute for Functional Genomics (IGF), University of Montpellier, Centre National de la Recherche Scientififique, Institut National de la Santé et de la Recherche Médicale, Montpellier, France
| | - Jennifer Hua
- Institute for Functional Genomics (IGF), University of Montpellier, Centre National de la Recherche Scientififique, Institut National de la Santé et de la Recherche Médicale, Montpellier, France
| | - Lauriane Ulmann
- Institute for Functional Genomics (IGF), University of Montpellier, Centre National de la Recherche Scientififique, Institut National de la Santé et de la Recherche Médicale, Montpellier, France
| | - Hélène Hirbec
- Institute for Functional Genomics (IGF), University of Montpellier, Centre National de la Recherche Scientififique, Institut National de la Santé et de la Recherche Médicale, Montpellier, France
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Kuan YH, Shih HC, Shyu BC. Involvement of P 2X 7 Receptors and BDNF in the Pathogenesis of Central Poststroke Pain. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1099:211-227. [PMID: 30306527 DOI: 10.1007/978-981-13-1756-9_18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Central pain is commonly found in patients with neurological complications that are associated with central nervous system insult, such as stroke. It can result directly from central nervous system injury. Impairments in sensory discrimination can make it challenging to differentiate central neuropathic pain from other types of pain or spasticity. Central neuropathic pain may also begin months to years after the injury, further obscuring the recognition of its association with past neurologic injury. This chapter focuses on the involvement of P2X7 receptor and brain-derived neurotrophic factor (BDNF) in central poststroke pain (CPSP). An experimental animal model is introduced that assesses the pathogenesis of central neuropathic pain, and pharmacological approaches and neuromodulatory treatments of this difficult-to-treat pain syndrome are discussed.
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Affiliation(s)
- Yung-Hui Kuan
- Division of Neuroscience, Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Hsi-Chien Shih
- Division of Neuroscience, Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Bai-Chuang Shyu
- Division of Neuroscience, Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan.
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