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Mogil JS, Parisien M, Esfahani SJ, Diatchenko L. Sex differences in mechanisms of pain hypersensitivity. Neurosci Biobehav Rev 2024; 163:105749. [PMID: 38838876 DOI: 10.1016/j.neubiorev.2024.105749] [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: 04/10/2024] [Revised: 05/23/2024] [Accepted: 06/02/2024] [Indexed: 06/07/2024]
Abstract
The introduction of sex-as-a-biological-variable policies at funding agencies around the world has led to an explosion of very recent observations of sex differences in the biology underlying pain. This review considers evidence of sexually dimorphic mechanisms mediating pain hypersensitivity, derived from modern assays of persistent pain in rodent animal models. Three well-studied findings are described in detail: the male-specific role of spinal cord microglia, the female-specific role of calcitonin gene-related peptide (CGRP), and the female-specific role of prolactin and its receptor. Other findings of sex-specific molecular involvement in pain are subjected to pathway analyses and reveal at least one novel hypothesis: that females may preferentially use Th1 and males Th2 T cell activity to mediate chronic pain.
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Affiliation(s)
- Jeffrey S Mogil
- Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC H3A 1B1, Canada.
| | - Marc Parisien
- Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC H3A 1B1, Canada
| | - Sahel J Esfahani
- Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC H3A 1B1, Canada
| | - Luda Diatchenko
- Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC H3A 1B1, Canada
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2
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Zubia MV, Yong AJH, Holtz KM, Huang EJ, Jan YN, Jan LY. TMEM16F exacerbates tau pathology and mediates phosphatidylserine exposure in phospho-tau-burdened neurons. Proc Natl Acad Sci U S A 2024; 121:e2311831121. [PMID: 38941274 PMCID: PMC11228522 DOI: 10.1073/pnas.2311831121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 06/04/2024] [Indexed: 06/30/2024] Open
Abstract
TMEM16F is a calcium-activated phospholipid scramblase and nonselective ion channel, which allows the movement of lipids bidirectionally across the plasma membrane. While the functions of TMEM16F have been extensively characterized in multiple cell types, the role of TMEM16F in the central nervous system remains largely unknown. Here, we sought to study how TMEM16F in the brain may be involved in neurodegeneration. Using a mouse model that expresses the pathological P301S human tau (PS19 mouse), we found reduced tauopathy and microgliosis in 6- to 7-mo-old PS19 mice lacking TMEM16F. Furthermore, this reduction of pathology can be recapitulated in the PS19 mice with TMEM16F removed from neurons, while removal of TMEM16F from microglia of PS19 mice did not significantly impact tauopathy at this time point. Moreover, TMEM16F mediated aberrant phosphatidylserine exposure in neurons with phospho-tau burden. These studies raise the prospect of targeting TMEM16F in neurons as a potential treatment of neurodegeneration.
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Affiliation(s)
- Mario V Zubia
- Biomedical Sciences Graduate Program, University of California, San Francisco, CA 94143
- Department of Physiology, University of California, San Francisco, CA 94143
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94143
- HHMI, University of California, San Francisco, CA 94143
| | - Adeline J H Yong
- Department of Physiology, University of California, San Francisco, CA 94143
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94143
- HHMI, University of California, San Francisco, CA 94143
| | | | - Eric J Huang
- Biomedical Sciences Graduate Program, University of California, San Francisco, CA 94143
- Department of Pathology, University of California, San Francisco, CA 94143
| | - Yuh Nung Jan
- Department of Physiology, University of California, San Francisco, CA 94143
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94143
- HHMI, University of California, San Francisco, CA 94143
| | - Lily Y Jan
- Department of Physiology, University of California, San Francisco, CA 94143
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94143
- HHMI, University of California, San Francisco, CA 94143
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3
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Jain A, Hakim S, Woolf CJ. Immune drivers of physiological and pathological pain. J Exp Med 2024; 221:e20221687. [PMID: 38607420 PMCID: PMC11010323 DOI: 10.1084/jem.20221687] [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: 05/19/2023] [Revised: 09/25/2023] [Accepted: 04/02/2024] [Indexed: 04/13/2024] Open
Abstract
Physiological pain serves as a warning of exposure to danger and prompts us to withdraw from noxious stimuli to prevent tissue damage. Pain can also alert us of an infection or organ dysfunction and aids in locating such malfunction. However, there are instances where pain is purely pathological, such as unresolved pain following an inflammation or injury to the nervous system, and this can be debilitating and persistent. We now appreciate that immune cells are integral to both physiological and pathological pain, and that pain, in consequence, is not strictly a neuronal phenomenon. Here, we discuss recent findings on how immune cells in the skin, nerve, dorsal root ganglia, and spinal cord interact with somatosensory neurons to mediate pain. We also discuss how both innate and adaptive immune cells, by releasing various ligands and mediators, contribute to the initiation, modulation, persistence, or resolution of various modalities of pain. Finally, we propose that the neuroimmune axis is an attractive target for pain treatment, but the challenges in objectively quantifying pain preclinically, variable sex differences in pain presentation, as well as adverse outcomes associated with immune system modulation, all need to be considered in the development of immunotherapies against pain.
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Affiliation(s)
- Aakanksha Jain
- F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Boston, MA, USA
| | - Sara Hakim
- F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Boston, MA, USA
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Clifford J. Woolf
- F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Boston, MA, USA
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
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Shan L, Xu K, Ji L, Zeng Q, Liu Y, Wu Y, Chen Y, Li Y, Hu Q, Wu J, Xu Y, Luo Y, Li C, Wu C, Jiang C, Wang Z. Injured sensory neurons-derived galectin-3 contributes to neuropathic pain via programming microglia in the spinal dorsal horn. Brain Behav Immun 2024; 117:80-99. [PMID: 38190982 DOI: 10.1016/j.bbi.2024.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 12/11/2023] [Accepted: 01/03/2024] [Indexed: 01/10/2024] Open
Abstract
Emerging studies have demonstrated spinal microglia play a critical role in central sensitization and contribute to chronic pain. Although several mediators that contribute to microglia activation have been identified, the mechanism of microglia activation and its functionally diversified mechanisms in pathological pain are still unclear. Here we report that injured sensory neurons-derived Galectin-3 (Gal3) activates and reprograms microglia in the spinal dorsal horn (SDH) and contributes to neuropathic pain. Firstly, Gal3 is predominantly expressed in the isolectin B4 (IB4)-positive non-peptidergic sensory neurons and significantly up-regulated in dorsal root ganglion (DRG) neurons and primary afferent terminals in SDH in the partial sciatic nerve ligation (pSNL)-induced neuropathic pain model. Gal3 knockout (Gal3 KO) mice showed a significant decrease in mechanical allodynia and Gal3 inhibitor TD-139 produced a significant anti-allodynia effect in the pSNL model. Furthermore, pSNL-induced microgliosis was compromised in Gal3 KO mice. Additionally, intrathecal injection of Gal3 produces remarkable mechanical allodynia by direct activation of microglia, which have enhanced inflammatory responses with TNF-α and IL-1β up-regulation. Thirdly, using single-nuclear RNA sequencing (snRNA-seq), we identified that Gal3 targets microglia and induces reprogramming of microglia, which may contribute to neuropathic pain establishment. Finally, Gal3 enhances excitatory synaptic transmission in excitatory neurons in the SDH via microglia activation. Our findings reveal that injured sensory neurons-derived Gal3 programs microglia in the SDH and contribute to neuropathic pain.
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Affiliation(s)
- Leyan Shan
- Department of Medical Neuroscience, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Kangtai Xu
- Department of Anesthesiology, Shenzhen People's Hospital, The First Affiliated Hospital, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Luyao Ji
- Department of Medical Neuroscience, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Qian Zeng
- Department of Anesthesiology, Shenzhen People's Hospital, The First Affiliated Hospital, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China; Department of Pain Medicine and Shenzhen Municipal Key Laboratory for Pain Medicine, The 6th Affiliated Hospital of Shenzhen University Medical School, Shenzhen, Guangdong, China
| | - Yaqi Liu
- Department of Medical Neuroscience, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Yifei Wu
- Department of Medical Neuroscience, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Yiming Chen
- Department of Medical Neuroscience, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Yitong Li
- Department of Medical Neuroscience, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Qiaodan Hu
- Department of Medical Neuroscience, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Jiawei Wu
- Department of Medical Neuroscience, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Yuanfan Xu
- Department of Medical Neuroscience, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Yuhui Luo
- Department of Pain Medicine and Shenzhen Municipal Key Laboratory for Pain Medicine, The 6th Affiliated Hospital of Shenzhen University Medical School, Shenzhen, Guangdong, China
| | - Changlin Li
- Guangdong Institute of Intelligence Science and Technology, Hengqin, Zhuhai, Guangdong, China
| | - Chaoran Wu
- Department of Anesthesiology, Shenzhen People's Hospital, The First Affiliated Hospital, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Changyu Jiang
- Department of Pain Medicine and Shenzhen Municipal Key Laboratory for Pain Medicine, The 6th Affiliated Hospital of Shenzhen University Medical School, Shenzhen, Guangdong, China.
| | - Zilong Wang
- Department of Medical Neuroscience, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China; Key University Laboratory of Metabolism and Health of Guangdong School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China; SUSTech Center for Pain Medicine, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China.
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Han S, Jiang B, Ren J, Gao F, Wen J, Zhou T, Wang L, Wei X. Impaired Lactate Release in Dorsal CA1 Astrocytes Contributed to Nociceptive Sensitization and Comorbid Memory Deficits in Rodents. Anesthesiology 2024; 140:538-557. [PMID: 37651459 DOI: 10.1097/aln.0000000000004756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
BACKGROUND Memory deficits are a common comorbid disorder in patients suffering from neuropathic pain. The mechanisms underlying the comorbidities remain elusive. The hypothesis of this study was that impaired lactate release from dysfunctional astrocytes in dorsal hippocampal CA1 contributed to memory deficits. METHODS A spared nerve injury model was established to induce both pain and memory deficits in rats and mice of both sexes. von Frey tests, novel object recognition, and conditioned place preference tests were applied to evaluate the behaviors. Whole-cell recording, fiber photometry, Western blotting, and immunohistochemistry combined with intracranial injections were used to explore the underlying mechanisms. RESULTS Animals with spared sciatic nerve injury that had displayed nociception sensitization or memory deficit comorbidities demonstrated a reduction in the intrinsic excitability of pyramidal neurons, accompanied by reduced Ca2+ activation in astrocytes (ΔF/F, sham: 6 ± 2%; comorbidity: 2 ± 0.4%) and a decrease in the expression of glial fibrillary acidic protein and lactate levels in the dorsal CA1. Exogenous lactate supply or increasing endogenous lactate release by chemogenetic activation of astrocytes alleviated this comorbidity by enhancing the cell excitability (129 ± 4 vs. 88 ± 10 for 3.5 mM lactate) and potentiating N-methyl-d-aspartate receptor-mediated excitatory postsynaptic potentials of pyramidal neurons. In contrast, inhibition of lactate synthesis, blocking lactate transporters, or chemogenetic inhibition of astrocytes resulted in comorbidity-like behaviors in naive animals. Notably, β2-adrenergic receptors in astrocytes but not neurons were downregulated in dorsal CA1 after spared nerve injury. Microinjection of a β2 receptor agonist into dorsal CA1 or activation of the noradrenergic projections onto the hippocampus from the locus coeruleus alleviated the comorbidity, possibly by increasing lactate release. CONCLUSIONS Impaired lactate release from dysfunctional astrocytes, which could be rescued by activation of the locus coeruleus, led to nociception and memory deficits after peripheral nerve injury. EDITOR’S PERSPECTIVE
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Affiliation(s)
- Shuang Han
- Department of Human Anatomy and Physiology, and Pain Research Center, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Bin Jiang
- Guangdong Provincial Key Laboratory of Brain Function and Disease, and Department of Human Anatomy and Physiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Jiale Ren
- Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Feng Gao
- Department of Human Anatomy and Physiology, and Pain Research Center, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Junjian Wen
- Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Taihe Zhou
- Department of Human Anatomy and Physiology, and Pain Research Center, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Laijian Wang
- Department of Human Anatomy and Physiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Xuhong Wei
- Guangdong Provincial Key Laboratory of Brain Function and Disease, Department of Human Anatomy and Physiology, and Pain Research Center, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
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Wei HR, Tang L, Yang XL, Chen CM, Li LX, Mao Y, Wang D, Kang F, Qun S, Zhang Z, Cao P, Jin Y. A microglial activation cascade across cortical regions underlies secondary mechanical hypersensitivity to amputation. Cell Rep 2024; 43:113804. [PMID: 38368612 DOI: 10.1016/j.celrep.2024.113804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 08/03/2023] [Accepted: 01/31/2024] [Indexed: 02/20/2024] Open
Abstract
Neural mechanisms underlying amputation-related secondary pain are unclear. Using in vivo two-photon imaging, three-dimensional reconstruction, and fiber photometry recording, we show that a microglial activation cascade from the primary somatosensory cortex of forelimb (S1FL) to the primary somatosensory cortex of hindlimb (S1HL) mediates the disinhibition and subsequent hyperexcitation of glutamatergic neurons in the S1HL (S1HLGlu), which then drives secondary mechanical hypersensitivity development in ipsilateral hindpaws of mice with forepaw amputation. Forepaw amputation induces rapid S1FL microglial activation that further activates S1HL microglia via the CCL2-CCR2 signaling pathway. Increased engulfment of GABAergic presynapses by activated microglia stimulates S1HLGlu neuronal activity, ultimately leading to secondary mechanical hypersensitivity of hindpaws. It is widely believed direct neuronal projection drives interactions between distinct brain regions to prime specific behaviors. Our study reveals microglial interactions spanning different subregions of the somatosensory cortex to drive a maladaptive neuronal response underlying secondary mechanical hypersensitivity at non-injured sites.
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Affiliation(s)
- Hong-Rui Wei
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Lan Tang
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Xin-Lu Yang
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China; Department of Anesthesiology, The First Affiliated Hospital of Wannan Medical College, Wuhu, Anhui 241000, China
| | - Chang-Mao Chen
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Le-Xian Li
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Yu Mao
- Department of Anesthesiology, The First Affiliated Hospital of Anhui Medical University, Hefei 230022, China
| | - Di Wang
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Fang Kang
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Sen Qun
- Stroke Center and Department of Neurology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Zhi Zhang
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China; Center for Advanced Interdisciplinary Science and Biomedicine, Institute of Health and Medicine, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China.
| | - Peng Cao
- Stroke Center and Department of Neurology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China.
| | - Yan Jin
- Stroke Center and Department of Neurology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China.
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7
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Kim E, Bang J, Sung JH, Lee J, Shin DH, Kim S, Lee BC. Generation of human TMEM16F-specific affibodies using purified TMEM16F. Front Mol Biosci 2024; 10:1319251. [PMID: 38274091 PMCID: PMC10808743 DOI: 10.3389/fmolb.2023.1319251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 12/27/2023] [Indexed: 01/27/2024] Open
Abstract
Introduction: TMEM16 family proteins are involved in a variety of functions, including ion transport, phospholipid scrambling, and the regulation of membrane proteins. Among them, TMEM16F has dual functions as a phospholipid scramblase and a nonselective ion channel. TMEM16F is widely expressed and functions in platelet activation during blood clotting, bone formation, and T cell activation. Despite the functional importance of TMEM16F, the modulators of TMEM16F function have not been sufficiently studied. Method: In this study, we generated TMEM16F-specific affibodies by performing phage display with brain-specific TMEM16F (hTMEM16F) variant 1 purified from GnTi- cells expressing this variant in the presence of digitonin as a detergent. Purified human TMEM16F protein, which was proficient in transporting phospholipids in a Ca2+-dependent manner in proteoliposomes, was coated onto plates and then the phage library was added to fish out TMEM16F-binding affibodies. For the validation of interaction between affibodies and TMEM16F proteins, ELISA, bio-layer interferometry, and size exclusion chromatography were conducted. Results and Discussion: As a result, the full sequences of 38 candidates were acquired from 98 binding candidates. Then, we selected 10 candidates and purified seven of them from E. coli expressing these candidates. Using various assays, we confirmed that two affibodies bound to human TMEM16F with high affinity. These affibodies can be useful for therapeutical and diagnostic applications of TMEM16F-related cancer and neurodegenerative diseases. Future studies will be required to investigate the effects of these affibodies on TMEM16F function.
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Affiliation(s)
- Eunyoung Kim
- Korea Brain Research Institute, Neurovascular Unit Research Group, Daegu, Republic of Korea
| | - Jinho Bang
- Korea Institute of Ceramic Engineering and Technology, Bio-Healthcare Materials Center, Cheongju, Republic of Korea
- College of Pharmacy, Chungbuk National University, Cheongju, Republic of Korea
| | - Ji Hye Sung
- Korea Brain Research Institute, Neurovascular Unit Research Group, Daegu, Republic of Korea
| | - Jonghwan Lee
- Korea Institute of Ceramic Engineering and Technology, Bio-Healthcare Materials Center, Cheongju, Republic of Korea
| | - Dae Hwan Shin
- College of Pharmacy, Chungbuk National University, Cheongju, Republic of Korea
| | - Sunghyun Kim
- Korea Institute of Ceramic Engineering and Technology, Bio-Healthcare Materials Center, Cheongju, Republic of Korea
| | - Byoung-Cheol Lee
- Korea Brain Research Institute, Neurovascular Unit Research Group, Daegu, Republic of Korea
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8
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Xu Y, Koch SC, Chamessian A, He Q, Sundukova M, Heppenstall P, Ji R, Fitzgerald M, Beggs S. Microglial Refinement of A-Fiber Projections in the Postnatal Spinal Cord Dorsal Horn Is Required for Normal Maturation of Dynamic Touch. J Neurosci 2024; 44:e1354232023. [PMID: 37989592 PMCID: PMC10860632 DOI: 10.1523/jneurosci.1354-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 11/07/2023] [Accepted: 11/12/2023] [Indexed: 11/23/2023] Open
Abstract
Sensory systems are shaped in postnatal life by the refinement of synaptic connectivity. In the dorsal horn of the spinal cord, somatosensory circuits undergo postnatal activity-dependent reorganization, including the refinement of primary afferent A-fiber terminals from superficial to deeper spinal dorsal horn laminae which is accompanied by decreases in cutaneous sensitivity. Here, we show in the mouse that microglia, the resident immune cells in the CNS, phagocytose A-fiber terminals in superficial laminae in the first weeks of life. Genetic perturbation of microglial engulfment during the initial postnatal period in either sex prevents the normal process of A-fiber refinement and elimination, resulting in an altered sensitivity of dorsal horn cells to dynamic tactile cutaneous stimulation, and behavioral hypersensitivity to dynamic touch. Thus, functional microglia are necessary for the normal postnatal development of dorsal horn sensory circuits. In the absence of microglial engulfment, superfluous A-fiber projections remain in the dorsal horn, and the balance of sensory connectivity is disrupted, leading to lifelong hypersensitivity to dynamic touch.
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Affiliation(s)
- Yajing Xu
- Neuroscience, Physiology and Pharmacology, UCL, London, WC1E 6BT United Kingdom
| | - Stephanie C Koch
- Neuroscience, Physiology and Pharmacology, UCL, London, WC1E 6BT United Kingdom
| | - Alexander Chamessian
- Duke University School of Medicine, Duke University, Durham, North Carolina 27710
| | - Qianru He
- Duke University School of Medicine, Duke University, Durham, North Carolina 27710
| | - Mayya Sundukova
- SISSA (International School for Advanced Studies), 34136 Trieste, Italy
| | - Paul Heppenstall
- SISSA (International School for Advanced Studies), 34136 Trieste, Italy
| | - RuRong Ji
- Duke University School of Medicine, Duke University, Durham, North Carolina 27710
| | - Maria Fitzgerald
- Neuroscience, Physiology and Pharmacology, UCL, London, WC1E 6BT United Kingdom
| | - Simon Beggs
- Neuroscience, Physiology and Pharmacology, UCL, London, WC1E 6BT United Kingdom
- Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London, WC1N 1EH United Kingdom
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9
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Li L, Li T, Qu X, Sun G, Fu Q, Han G. Stress/cell death pathways, neuroinflammation, and neuropathic pain. Immunol Rev 2024; 321:33-51. [PMID: 37688390 DOI: 10.1111/imr.13275] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Revised: 08/14/2023] [Accepted: 08/27/2023] [Indexed: 09/10/2023]
Abstract
Neuropathic pain is a common and debilitating modality of chronic pain induced by a lesion or disease of the somatosensory nervous system. Albeit the elucidation of numerous pathophysiological mechanisms and the development of potential treatment compounds, safe and reliable therapies of neuropathic pain remain poor. Multiple stress/cell death pathways have been shown to be implicated in neuroinflammation during neuropathic pain. Here, we summarize the current knowledge of stress/cell death pathways and present an overview of the roles and molecular mechanisms of stress/cell death pathways in neuroinflammation during neuropathic pain, covering intrinsic and extrinsic apoptosis, autophagy, mitophagy, ferroptosis, pyroptosis, necroptosis, and phagoptosis. Small molecule compounds that modulate stress/cell death pathways in alleviating neuropathic pain are discussed mainly based on preclinical neuropathic pain models. These findings will contribute to in-depth understanding of the pathological processes during neuropathic pain as well as bridge the gap between basic and translational research to uncover new neuroprotective interventions.
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Affiliation(s)
- Lu Li
- Department of Anesthesiology, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China
| | - Tian Li
- School of Basic Medicine, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Xinyu Qu
- Department of Anesthesiology, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China
| | - Guangwei Sun
- Department of Anesthesiology, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China
| | - Qi Fu
- Department of Anesthesiology, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China
| | - Guang Han
- Department of Anesthesiology, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China
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10
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Ramos D, Cruz CD. Involvement of microglia in chronic neuropathic pain associated with spinal cord injury - a systematic review. Rev Neurosci 2023; 34:933-950. [PMID: 37490300 DOI: 10.1515/revneuro-2023-0031] [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: 03/17/2023] [Accepted: 06/10/2023] [Indexed: 07/26/2023]
Abstract
In recent decade microglia have been found to have a central role in the development of chronic neuropathic pain after injury to the peripheral nervous system. It is widely accepted that peripheral nerve injury triggers microglial activation in the spinal cord, which contributes to heightened pain sensation and eventually chronic pain states. The contribution of microglia to chronic pain arising after injury to the central nervous system, such as spinal cord injury (SCI), has been less studied, but there is evidence supporting microglial contribution to central neuropathic pain. In this systematic review, we focused on post-SCI microglial activation and how it is linked to emergence and maintenance of chronic neuropathic pain arising after SCI. We found that the number of studies using animal SCI models addressing microglial activity is still small, compared with the ones using peripheral nerve injury models. We have collected 20 studies for full inclusion in this review. Many mechanisms and cellular interactions are yet to be fully understood, although several studies report an increase of density and activity of microglia in the spinal cord, both in the vicinity of the injury and in the spared spinal tissue, as well as in the brain. Changes in microglial activity come with several molecular changes, including expression of receptors and activation of signalling pathways. As with peripheral neuropathic pain, microglia seem to be important players and might become a therapeutic target in the future.
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Affiliation(s)
- David Ramos
- Faculty of Medicine of Porto, University of Porto, Porto, Portugal
- Department of Biomedicine, Experimental Biology Unit, Department of Biomedicine, Faculty of Medicine of Porto, University of Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal
| | - Célia Duarte Cruz
- Department of Biomedicine, Experimental Biology Unit, Department of Biomedicine, Faculty of Medicine of Porto, University of Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal
- Translational Neurourology, IBMC and Instituto de Investigação e Inovação em Saúde-i3S, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
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11
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Kwak C, Finan GM, Park YR, Garg A, Harari O, Mun JY, Rhee HW, Kim TW. Proximity Proteome Analysis Reveals Novel TREM2 Interactors in the ER-Mitochondria Interface of Human Microglia. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.21.533722. [PMID: 38014048 PMCID: PMC10680561 DOI: 10.1101/2023.03.21.533722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Triggering receptor expressed on myeloid cells 2 (TREM2) plays a central role in microglial biology and the pathogenesis of Alzheimer's disease (AD). Besides DNAX-activating protein 12 (DAP12), a communal adaptor for TREM2 and many other receptors, other cellular interactors of TREM2 remain largely elusive. We employed a 'proximity labeling' approach using a biotin ligase, TurboID, for mapping protein-protein interactions in live mammalian cells. We discovered novel TREM2-proximal proteins with diverse functions, including those localized to the Mitochondria-ER contact sites (MERCs), a dynamic subcellular 'hub' implicated in a number of crucial cell physiology such as lipid metabolism. TREM2 deficiency alters the thickness (inter-organelle distance) of MERCs, a structural parameter of metabolic state, in microglia derived from human induced pluripotent stem cells. Our TurboID-based TREM2 interactome study suggest novel roles for TREM2 in the structural plasticity of the MERCs, raising the possibility that dysregulation of MERC-related TREM2 functions contribute to AD pathobiology.
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12
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Barcelon E, Chung S, Lee J, Lee SJ. Sexual Dimorphism in the Mechanism of Pain Central Sensitization. Cells 2023; 12:2028. [PMID: 37626838 PMCID: PMC10453375 DOI: 10.3390/cells12162028] [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: 06/15/2023] [Revised: 08/01/2023] [Accepted: 08/07/2023] [Indexed: 08/27/2023] Open
Abstract
It has long been recognized that men and women have different degrees of susceptibility to chronic pain. Greater recognition of the sexual dimorphism in chronic pain has resulted in increasing numbers of both clinical and preclinical studies that have identified factors and mechanisms underlying sex differences in pain sensitization. Here, we review sexually dimorphic pain phenotypes in various research animal models and factors involved in the sex difference in pain phenotypes. We further discuss putative mechanisms for the sexual dimorphism in pain sensitization, which involves sex hormones, spinal cord microglia, and peripheral immune cells. Elucidating the sexually dimorphic mechanism of pain sensitization may provide important clinical implications and aid the development of sex-specific therapeutic strategies to treat chronic pain.
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Affiliation(s)
- Ellane Barcelon
- Department of Physiology and Neuroscience, School of Dentistry, Dental Research Institute, Seoul National University, Seoul 08826, Republic of Korea; (E.B.); (S.C.); (J.L.)
| | - Seohyun Chung
- Department of Physiology and Neuroscience, School of Dentistry, Dental Research Institute, Seoul National University, Seoul 08826, Republic of Korea; (E.B.); (S.C.); (J.L.)
| | - Jaesung Lee
- Department of Physiology and Neuroscience, School of Dentistry, Dental Research Institute, Seoul National University, Seoul 08826, Republic of Korea; (E.B.); (S.C.); (J.L.)
- Department of Interdisciplinary Program in Neuroscience, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Sung Joong Lee
- Department of Physiology and Neuroscience, School of Dentistry, Dental Research Institute, Seoul National University, Seoul 08826, Republic of Korea; (E.B.); (S.C.); (J.L.)
- Department of Interdisciplinary Program in Neuroscience, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea
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13
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Time-dependent and selective microglia-mediated removal of spinal synapses in neuropathic pain. Cell Rep 2023; 42:112010. [PMID: 36656715 DOI: 10.1016/j.celrep.2023.112010] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Revised: 09/20/2022] [Accepted: 01/03/2023] [Indexed: 01/20/2023] Open
Abstract
Neuropathic pain is a debilitating condition resulting from damage to the nervous system. Imbalance of spinal excitation and inhibition has been proposed to contribute to neuropathic pain. However, the structural basis of this imbalance remains unknown. Using a preclinical model of neuropathic pain, we show that microglia selectively engulf spinal synapses that are formed by central neurons and spare those of peripheral sensory neurons. Furthermore, we reveal that removal of inhibitory and excitatory synapses exhibits distinct temporal patterns, in which microglia-mediated inhibitory synapse removal precedes excitatory synapse removal. We also find selective and gradual increase in complement depositions on dorsal horn synapses that corresponds to the temporal pattern of microglial synapse pruning activity and type-specific synapse loss. Together, these results define a specific role for microglia in the progression of neuropathic pain pathogenesis and implicate these immune cells in structural remodeling of dorsal horn circuitry.
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14
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Damo E, Agarwal A, Simonetti M. Activation of β2-Adrenergic Receptors in Microglia Alleviates Neuropathic Hypersensitivity in Mice. Cells 2023; 12:cells12020284. [PMID: 36672219 PMCID: PMC9856373 DOI: 10.3390/cells12020284] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 12/22/2022] [Accepted: 01/08/2023] [Indexed: 01/13/2023] Open
Abstract
Drugs enhancing the availability of noradrenaline are gaining prominence in the therapy of chronic neuropathic pain. However, underlying mechanisms are not well understood, and research has thus far focused on α2-adrenergic receptors and neuronal excitability. Adrenergic receptors are also expressed on glial cells, but their roles toward antinociception are not well deciphered. This study addresses the contribution of β2-adrenergic receptors (β2-ARs) to the therapeutic modulation of neuropathic pain in mice. We report that selective activation of β2-ARs with Formoterol inhibits pro-inflammatory signaling in microglia ex vivo and nerve injury-induced structural remodeling and functional activation of microglia in vivo. Systemic delivery of Formoterol inhibits behaviors related to neuropathic pain, such as mechanical hypersensitivity, cold allodynia as well as the aversive component of pain, and reverses chronically established neuropathic pain. Using conditional gene targeting for microglia-specific deletion of β2-ARs, we demonstrate that the anti-allodynic effects of Formoterol are primarily mediated by microglia. Although Formoterol also reduces astrogliosis at late stages of neuropathic pain, these functions are unrelated to β2-AR signaling in microglia. Our results underline the value of developing microglial β2-AR agonists for relief from neuropathic pain and clarify mechanistic underpinnings.
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Affiliation(s)
- Elisa Damo
- Institute of Pharmacology, Medical Faculty Heidelberg, Heidelberg University, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Amit Agarwal
- The Chica and Heinz Schaller Research Group, Institute of Anatomy and Cell Biology, Heidelberg University, Im Neuenheimer Feld 307, 69120 Heidelberg, Germany
- Interdisciplinary Center for Neurosciences, Heidelberg University, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Manuela Simonetti
- Institute of Pharmacology, Medical Faculty Heidelberg, Heidelberg University, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
- Correspondence:
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15
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Xiao QH, Sun XH, Cui ZQ, Hu XY, Yang T, Guan JW, Gu Y, Li HY, Zhang HY. TMEM16F may be a new therapeutic target for Alzheimer’s disease. Neural Regen Res 2023; 18:643-651. [DOI: 10.4103/1673-5374.350211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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16
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Chu XL, Song XZ, Li Q, Li YR, He F, Gu XS, Ming D. Basic mechanisms of peripheral nerve injury and treatment via electrical stimulation. Neural Regen Res 2022; 17:2185-2193. [PMID: 35259827 PMCID: PMC9083151 DOI: 10.4103/1673-5374.335823] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Previous studies on the mechanisms of peripheral nerve injury (PNI) have mainly focused on the pathophysiological changes within a single injury site. However, recent studies have indicated that within the central nervous system, PNI can lead to changes in both injury sites and target organs at the cellular and molecular levels. Therefore, the basic mechanisms of PNI have not been comprehensively understood. Although electrical stimulation was found to promote axonal regeneration and functional rehabilitation after PNI, as well as to alleviate neuropathic pain, the specific mechanisms of successful PNI treatment are unclear. We summarize and discuss the basic mechanisms of PNI and of treatment via electrical stimulation. After PNI, activity in the central nervous system (spinal cord) is altered, which can limit regeneration of the damaged nerve. For example, cell apoptosis and synaptic stripping in the anterior horn of the spinal cord can reduce the speed of nerve regeneration. The pathological changes in the posterior horn of the spinal cord can modulate sensory abnormalities after PNI. This can be observed in cases of ectopic discharge of the dorsal root ganglion leading to increased pain signal transmission. The injured site of the peripheral nerve is also an important factor affecting post-PNI repair. After PNI, the proximal end of the injured site sends out axial buds to innervate both the skin and muscle at the injury site. A slow speed of axon regeneration leads to low nerve regeneration. Therefore, it can take a long time for the proximal nerve to reinnervate the skin and muscle at the injured site. From the perspective of target organs, long-term denervation can cause atrophy of the corresponding skeletal muscle, which leads to abnormal sensory perception and hyperalgesia, and finally, the loss of target organ function. The mechanisms underlying the use of electrical stimulation to treat PNI include the inhibition of synaptic stripping, addressing the excessive excitability of the dorsal root ganglion, alleviating neuropathic pain, improving neurological function, and accelerating nerve regeneration. Electrical stimulation of target organs can reduce the atrophy of denervated skeletal muscle and promote the recovery of sensory function. Findings from the included studies confirm that after PNI, a series of physiological and pathological changes occur in the spinal cord, injury site, and target organs, leading to dysfunction. Electrical stimulation may address the pathophysiological changes mentioned above, thus promoting nerve regeneration and ameliorating dysfunction.
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Affiliation(s)
- Xiao-Lei Chu
- Academy of Medical Engineering and Translational Medicine, Tianjin University; Department of Rehabilitation, Tianjin Hospital, Tianjin, China
| | - Xi-Zi Song
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Qi Li
- Academy of Medical Engineering and Translational Medicine, Tianjin University; Department of Rehabilitation, Tianjin Hospital, Tianjin, China
| | - Yu-Ru Li
- College of Exercise & Health Sciences, Tianjin University of Sport, Tianjin, China
| | - Feng He
- College of Precision Instruments & Optoelectronics Engineering, Tianjin University, Tianjin, China
| | - Xiao-Song Gu
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Dong Ming
- Academy of Medical Engineering and Translational Medicine; College of Precision Instruments & Optoelectronics Engineering, Tianjin University, Tianjin, China
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17
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Abstract
Infection with SARS-CoV-2, the causative agent of the COVID-19 pandemic, originated in China and quickly spread across the globe. Despite tremendous economic and healthcare devastation, research on this virus has contributed to a better understanding of numerous molecular pathways, including those involving γ-aminobutyric acid (GABA), that will positively impact medical science, including neuropsychiatry, in the post-pandemic era. SARS-CoV-2 primarily enters the host cells through the renin–angiotensin system’s component named angiotensin-converting enzyme-2 (ACE-2). Among its many functions, this protein upregulates GABA, protecting not only the central nervous system but also the endothelia, the pancreas, and the gut microbiota. SARS-CoV-2 binding to ACE-2 usurps the neuronal and non-neuronal GABAergic systems, contributing to the high comorbidity of neuropsychiatric illness with gut dysbiosis and endothelial and metabolic dysfunctions. In this perspective article, we take a closer look at the pathology emerging from the viral hijacking of non-neuronal GABA and summarize potential interventions for restoring these systems.
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18
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Luo J, Lian Q, Zhu D, Zhao M, Mei T, Shang B, Yang Z, Liu C, Xu W, Zhou L, Wu K, Liu X, Lai Y, Mao F, Li W, Zuo C, Zhang K, Lin M, Zhuo Y, Liu Y, Lu L, Zhao L. PLSCR1 Promotes Apoptosis and Clearance of Retinal Ganglion Cells in Glaucoma Pathogenesis. Genes Dis 2022. [DOI: 10.1016/j.gendis.2022.05.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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19
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Behuria HG, Dash S, Sahu SK. Phospholipid Scramblases: Role in Cancer Progression and Anticancer Therapeutics. Front Genet 2022; 13:875894. [PMID: 35422844 PMCID: PMC9002267 DOI: 10.3389/fgene.2022.875894] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 03/11/2022] [Indexed: 11/13/2022] Open
Abstract
Phospholipid scramblases (PLSCRs) that catalyze rapid mixing of plasma membrane lipids result in surface exposure of phosphatidyl serine (PS), a lipid normally residing to the inner plasma membrane leaflet. PS exposure provides a chemotactic eat-me signal for phagocytes resulting in non-inflammatory clearance of apoptotic cells by efferocytosis. However, metastatic tumor cells escape efferocytosis through alteration of tumor microenvironment and apoptotic signaling. Tumor cells exhibit altered membrane features, high constitutive PS exposure, low drug permeability and increased multidrug resistance through clonal evolution. PLSCRs are transcriptionally up-regulated in tumor cells leading to plasma membrane remodeling and aberrant PS exposure on cell surface. In addition, PLSCRs interact with multiple cellular components to modulate cancer progression and survival. While PLSCRs and PS exposed on tumor cells are novel drug targets, many exogenous molecules that catalyze lipid scrambling on tumor plasma membrane are potent anticancer therapeutic molecules. In this review, we provide a comprehensive analysis of scramblase mediated signaling events, membrane alteration specific to tumor development and possible therapeutic implications of scramblases and PS exposure.
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Affiliation(s)
- Himadri Gourav Behuria
- Laboratory of Molecular Membrane Biology, Department of Biotechnology, Maharaja Sriram Chandra Bhanjadeo University, Baripada, India
| | - Sabyasachi Dash
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY, United States
| | - Santosh Kumar Sahu
- Laboratory of Molecular Membrane Biology, Department of Biotechnology, Maharaja Sriram Chandra Bhanjadeo University, Baripada, India
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20
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Anion and Cation Permeability of the Mouse TMEM16F Calcium-Activated Channel. Int J Mol Sci 2021; 22:ijms22168578. [PMID: 34445284 PMCID: PMC8395294 DOI: 10.3390/ijms22168578] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 07/31/2021] [Accepted: 08/04/2021] [Indexed: 12/27/2022] Open
Abstract
TMEM16F is involved in several physiological processes, such as blood coagulation, bone development and virus infections. This protein acts both as a Ca2+-dependent phospholipid scramblase and a Ca2+-activated ion channel but several studies have reported conflicting results about the ion selectivity of the TMEM16F-mediated current. Here, we have performed a detailed side-by-side comparison of the ion selectivity of TMEM16F using the whole-cell and inside-out excised patch configurations to directly compare the results. In inside-out configuration, Ca2+-dependent activation was fast and the TMEM16F-mediated current was activated in a few milliseconds, while in whole-cell recordings full activation required several minutes. We determined the relative permeability between Na+ and Cl¯ (PNa/PCl) using the dilution method in both configurations. The TMEM16F-mediated current was highly nonselective, but there were differences depending on the configuration of the recordings. In whole-cell recordings, PNa/PCl was approximately 0.5, indicating a slight preference for Cl¯ permeation. In contrast, in inside-out experiments the TMEM16F channel showed a higher permeability for Na+ with PNa/PCl reaching 3.7. Our results demonstrate that the time dependence of Ca2+ activation and the ion selectivity of TMEM16F depend on the recording configuration.
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21
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Zarei M, Sabetkasaei M, Moini Zanjani T, Sahebi Vaighan N. The effect of microglial inhibition on the expression of BDNF, KCC2, and GABAA receptor before and after the establishment of CCI-induced neuropathic pain model. Fundam Clin Pharmacol 2021; 36:277-285. [PMID: 34302382 DOI: 10.1111/fcp.12719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Accepted: 07/22/2021] [Indexed: 11/30/2022]
Abstract
Damage to the peripheral or central nervous system results in neuropathic pain. Based on a complicated mechanism, neuropathic pain has no efficient treatment so far. It has been well-known that the expression of some proteins (BDNF, KCC2, GABA-A) during neuropathic pain changes. Microglial cell activation is considered as a trigger to alter the expression of these proteins. In the current study, the effect of minocycline as a potent microglial activation inhibitor on the gene and protein expression of these neuropathic pain mediators was investigated. This experiment was done in two paradigms, preinjury and postinjury administration of minocycline. In each paradigm, male Wistar rats (weight 150-200 g, n = 6) were allocated to sham, control, and drug groups. Minocycline (30 mg/kg, i.p.) was injected 1 h before or at day seven after nerve injury and continued till day 14 in the preemptive or postinjury part of the study, respectively. After the last injection, the animals were decapitated and the lumbar part of the spinal cord was isolated to assess the expression of genes and proteins of interest. In the preventive study, minocycline increased the expression of KCC2 and GABA-A/γ2 proteins and decreased BDNF expression. On the other hand, the target gene expression and protein expression were not changed when minocycline was administered after nerve injury. It seems that minocycline was able to change the expression of proteins of interest merely when used before nerve damage.
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Affiliation(s)
- Malek Zarei
- Department of Pharmacology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Masoumeh Sabetkasaei
- Department of Pharmacology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Taraneh Moini Zanjani
- Department of Pharmacology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Navideh Sahebi Vaighan
- Department of Pharmacology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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22
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Ahmad KA, Shoaib RM, Ahsan MZ, Deng MY, Ma L, Apryani E, Li XY, Wang YX. Microglial IL-10 and β-endorphin expression mediates gabapentinoids antineuropathic pain. Brain Behav Immun 2021; 95:344-361. [PMID: 33862171 DOI: 10.1016/j.bbi.2021.04.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Revised: 04/11/2021] [Accepted: 04/12/2021] [Indexed: 12/24/2022] Open
Abstract
Gabapentinoids are recommended first-line treatments for neuropathic pain. They are neuronal voltage-dependent calcium channel α2δ-1 subunit ligands and have been suggested to attenuate neuropathic pain via interaction with neuronal α2δ-1 subunit. However, the current study revealed their microglial mechanisms underlying antineuropathic pain. Intrathecal injection of gabapentin, pregabalin and mirogabalin rapidly inhibited mechanical allodynia and thermal hyperalgesia, with projected ED50 values of 30.3, 6.2 and 1.5 µg (or 176.9, 38.9 and 7.2 nmol) and Emax values of 66%, 61% and 65% MPE respectively for mechanical allodynia. Intrathecal gabapentinoids stimulated spinal mRNA and protein expression of IL-10 and β-endorphin (but not dynorphin A) in neuropathic rats with the time point parallel to their inhibition of allodynia, which was observed in microglia but not astrocytes or neurons in spinal dorsal horns by using double immunofluorescence staining. Intrathecal gabapentin alleviated pain hypersensitivity in male/female neuropathic but not male sham rats, whereas it increased expression of spinal IL-10 and β-endorphin in male/female neuropathic and male sham rats. Treatment with gabapentin, pregabalin and mirogabalin specifically upregulated IL-10 and β-endorphin mRNA and protein expression in primary spinal microglial but not astrocytic or neuronal cells, with EC50 values of 41.3, 11.5 and 2.5 µM and 34.7, 13.3 and 2.8 µM respectively. Pretreatment with intrathecal microglial metabolic inhibitor minocycline, IL-10 antibody, β-endorphin antiserum or μ-opioid receptor antagonist CTAP (but not κ- or δ-opioid receptor antagonists) suppressed spinal gabapentinoids-inhibited mechanical allodynia. Immunofluorescence staining exhibited specific α2δ-1 expression in neurons but not microglia or astrocytes in the spinal dorsal horns or cultured primary spinal cells. Thus the results illustrate that gabapentinoids alleviate neuropathic pain through stimulating expression of spinal microglial IL-10 and consequent β-endorphin.
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Affiliation(s)
- Khalil Ali Ahmad
- King's Lab, Shanghai Jiao Tong University School of Pharmacy, 800 Dongchuan Road, Shanghai 200240, China
| | - Rana Muhammad Shoaib
- King's Lab, Shanghai Jiao Tong University School of Pharmacy, 800 Dongchuan Road, Shanghai 200240, China
| | - Muhammad Zaeem Ahsan
- King's Lab, Shanghai Jiao Tong University School of Pharmacy, 800 Dongchuan Road, Shanghai 200240, China
| | - Meng-Yan Deng
- King's Lab, Shanghai Jiao Tong University School of Pharmacy, 800 Dongchuan Road, Shanghai 200240, China
| | - Le Ma
- King's Lab, Shanghai Jiao Tong University School of Pharmacy, 800 Dongchuan Road, Shanghai 200240, China
| | - Evhy Apryani
- King's Lab, Shanghai Jiao Tong University School of Pharmacy, 800 Dongchuan Road, Shanghai 200240, China
| | - Xin-Yan Li
- King's Lab, Shanghai Jiao Tong University School of Pharmacy, 800 Dongchuan Road, Shanghai 200240, China
| | - Yong-Xiang Wang
- King's Lab, Shanghai Jiao Tong University School of Pharmacy, 800 Dongchuan Road, Shanghai 200240, China.
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23
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P2X7 Receptors and TMEM16 Channels Are Functionally Coupled with Implications for Macropore Formation and Current Facilitation. Int J Mol Sci 2021; 22:ijms22126542. [PMID: 34207150 PMCID: PMC8234106 DOI: 10.3390/ijms22126542] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/04/2021] [Accepted: 06/07/2021] [Indexed: 02/03/2023] Open
Abstract
P2X7 receptors (P2X7) are cationic channels involved in many diseases. Following their activation by extracellular ATP, distinct signaling pathways are triggered, which lead to various physiological responses such as the secretion of pro-inflammatory cytokines or the modulation of cell death. P2X7 also exhibit unique behaviors, such as “macropore” formation, which corresponds to enhanced large molecule cell membrane permeability and current facilitation, which is caused by prolonged activation. These two phenomena have often been confounded but, thus far, no clear mechanisms have been resolved. Here, by combining different approaches including whole-cell and single-channel recordings, pharmacological and biochemical assays, CRISPR/Cas9 technology and cell imaging, we provide evidence that current facilitation and macropore formation involve functional complexes comprised of P2X7 and TMEM16, a family of Ca2+-activated ion channel/scramblases. We found that current facilitation results in an increase of functional complex-embedded P2X7 open probability, a result that is recapitulated by plasma membrane cholesterol depletion. We further show that macropore formation entails two distinct large molecule permeation components, one of which requires functional complexes featuring TMEM16F subtype, the other likely being direct permeation through the P2X7 pore itself. Such functional complexes can be considered to represent a regulatory hub that may orchestrate distinct P2X7 functionalities.
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24
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Role of microglia and P2X4 receptors in chronic pain. Pain Rep 2021; 6:e864. [PMID: 33981920 PMCID: PMC8108579 DOI: 10.1097/pr9.0000000000000864] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/01/2020] [Accepted: 09/08/2020] [Indexed: 12/15/2022] Open
Abstract
This study summarizes current understanding of the role of microglia and P2X4 receptor in chronic pain including neuropathic pain and of their therapeutic potential. Pain plays an indispensable role as an alarm system to protect us from dangers or injuries. However, neuropathic pain, a debilitating pain condition caused by damage to the nervous system, persists for a long period even in the absence of dangerous stimuli or after injuries have healed. In this condition, pain becomes a disease itself rather than the alarm system and is often resistant to currently available medications. A growing body of evidence indicates that microglia, a type of macrophages residing in the central nervous system, play a crucial role in the pathogenesis of neuropathic pain. Whenever microglia in the spinal cord detect a damaging signal within the nervous system, they become activated and cause diverse alterations that change neural excitability, leading to the development of neuropathic pain. For over a decade, several lines of molecular and cellular mechanisms that define microglial activation and subsequently altered pain transmission have been proposed. In particular, P2X4 receptors (a subtype of purinergic receptors) expressed by microglia have been investigated as an essential molecule for neuropathic pain. In this review article, we describe our understanding of the mechanisms by which activated microglia cause neuropathic pain through P2X4 receptors, their involvement in several pathological contexts, and recent efforts to develop new drugs targeting microglia and P2X4 receptors.
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25
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The Groovy TMEM16 Family: Molecular Mechanisms of Lipid Scrambling and Ion Conduction. J Mol Biol 2021; 433:166941. [PMID: 33741412 DOI: 10.1016/j.jmb.2021.166941] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 03/09/2021] [Accepted: 03/09/2021] [Indexed: 12/28/2022]
Abstract
The TMEM16 family of membrane proteins displays a remarkable functional dichotomy - while some family members function as Ca2+-activated anion channels, the majority of characterized TMEM16 homologs are Ca2+-activated lipid scramblases, which catalyze the exchange of phospholipids between the two membrane leaflets. Furthermore, some TMEM16 scramblases can also function as channels. Due to their involvement in important physiological processes, the family has been actively studied ever since their molecular identity was unraveled. In this review, we will summarize the recent advances in the field and how they influenced our view of TMEM16 family function and evolution. Structural, functional and computational studies reveal how relatively small rearrangements in the permeation pathway are responsible for the observed functional duality: while TMEM16 scramblases can adopt both ion- and lipid conductive conformations, TMEM16 channels can only populate the former. Recent data further provides the molecular details of a stepwise activation mechanism, which is initiated by Ca2+ binding and modulated by various cellular factors, including lipids. TMEM16 function and the surrounding membrane properties are inextricably intertwined, with the protein inducing bilayer deformations associated with scrambling, while the surrounding lipids modulate TMEM16 conformation and activity.
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26
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Midavaine É, Côté J, Marchand S, Sarret P. Glial and neuroimmune cell choreography in sexually dimorphic pain signaling. Neurosci Biobehav Rev 2021; 125:168-192. [PMID: 33582232 DOI: 10.1016/j.neubiorev.2021.01.023] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 11/03/2020] [Accepted: 01/25/2021] [Indexed: 12/17/2022]
Abstract
Chronic pain is a major global health issue that affects all populations regardless of sex, age, ethnicity/race, or country of origin, leading to persistent physical and emotional distress and to the loss of patients' autonomy and quality of life. Despite tremendous efforts in the elucidation of the mechanisms contributing to the pathogenesis of chronic pain, the identification of new potential pain targets, and the development of novel analgesics, the pharmacological treatment options available for pain management remain limited, and most novel pain medications have failed to achieve advanced clinical development, leaving many patients with unbearable and undermanaged pain. Sex-specific susceptibility to chronic pain conditions as well as sex differences in pain sensitivity, pain tolerance and analgesic efficacy are increasingly recognized in the literature and have thus prompted scientists to seek mechanistic explanations. Hence, recent findings have highlighted that the signaling mechanisms underlying pain hypersensitivity are sexually dimorphic, which sheds light on the importance of conducting preclinical and clinical pain research on both sexes and of developing sex-specific pain medications. This review thus focuses on the clinical and preclinical evidence supporting the existence of sex differences in pain neurobiology. Attention is drawn to the sexually dimorphic role of glial and immune cells, which are both recognized as key players in neuroglial maladaptive plasticity at the origin of the transition from acute pain to chronic pathological pain. Growing evidence notably attributes to microglial cells a pivotal role in the sexually dimorphic pain phenotype and in the sexually dimorphic analgesic efficacy of opioids. This review also summarizes the recent advances in understanding the pathobiology underpinning the development of pain hypersensitivity in both males and females in different types of pain conditions, with particular emphasis on the mechanistic signaling pathways driving sexually dimorphic pain responses.
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Affiliation(s)
- Élora Midavaine
- Department of Pharmacology-Physiology, Institut de pharmacologie de Sherbrooke, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada; Centre de recherche du Centre hospitalier universitaire de Sherbrooke, CIUSSS de l'Estrie - CHUS, Sherbrooke, Québec, Canada.
| | - Jérôme Côté
- Department of Pharmacology-Physiology, Institut de pharmacologie de Sherbrooke, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada; Centre de recherche du Centre hospitalier universitaire de Sherbrooke, CIUSSS de l'Estrie - CHUS, Sherbrooke, Québec, Canada
| | - Serge Marchand
- Department of Pharmacology-Physiology, Institut de pharmacologie de Sherbrooke, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada; Centre de recherche du Centre hospitalier universitaire de Sherbrooke, CIUSSS de l'Estrie - CHUS, Sherbrooke, Québec, Canada
| | - Philippe Sarret
- Department of Pharmacology-Physiology, Institut de pharmacologie de Sherbrooke, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada; Centre de recherche du Centre hospitalier universitaire de Sherbrooke, CIUSSS de l'Estrie - CHUS, Sherbrooke, Québec, Canada.
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Berglund R, Guerreiro-Cacais AO, Adzemovic MZ, Zeitelhofer M, Lund H, Ewing E, Ruhrmann S, Nutma E, Parsa R, Thessen-Hedreul M, Amor S, Harris RA, Olsson T, Jagodic M. Microglial autophagy-associated phagocytosis is essential for recovery from neuroinflammation. Sci Immunol 2020; 5:5/52/eabb5077. [PMID: 33067381 DOI: 10.1126/sciimmunol.abb5077] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 09/24/2020] [Indexed: 01/07/2023]
Abstract
Multiple sclerosis (MS) is a leading cause of incurable progressive disability in young adults caused by inflammation and neurodegeneration in the central nervous system (CNS). The capacity of microglia to clear tissue debris is essential for maintaining and restoring CNS homeostasis. This capacity diminishes with age, and age strongly associates with MS disease progression, although the underlying mechanisms are still largely elusive. Here, we demonstrate that the recovery from CNS inflammation in a murine model of MS is dependent on the ability of microglia to clear tissue debris. Microglia-specific deletion of the autophagy regulator Atg7, but not the canonical macroautophagy protein Ulk1, led to increased intracellular accumulation of phagocytosed myelin and progressive MS-like disease. This impairment correlated with a microglial phenotype previously associated with neurodegenerative pathologies. Moreover, Atg7-deficient microglia showed notable transcriptional and functional similarities to microglia from aged wild-type mice that were also unable to clear myelin and recover from disease. In contrast, induction of autophagy in aged mice using the disaccharide trehalose found in plants and fungi led to functional myelin clearance and disease remission. Our results demonstrate that a noncanonical form of autophagy in microglia is responsible for myelin degradation and clearance leading to recovery from MS-like disease and that boosting this process has a therapeutic potential for age-related neuroinflammatory conditions.
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Affiliation(s)
- Rasmus Berglund
- Department of Clinical Neuroscience, Karolinska Institutet, Center for Molecular Medicine, Karolinska University Hospital, 171 76 Stockholm, Sweden
| | - Andre Ortlieb Guerreiro-Cacais
- Department of Clinical Neuroscience, Karolinska Institutet, Center for Molecular Medicine, Karolinska University Hospital, 171 76 Stockholm, Sweden
| | - Milena Z Adzemovic
- Department of Clinical Neuroscience, Karolinska Institutet, Center for Molecular Medicine, Karolinska University Hospital, 171 76 Stockholm, Sweden
| | - Manuel Zeitelhofer
- Division of Vascular Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 171 65 Solna, Sweden
| | - Harald Lund
- Department of Clinical Neuroscience, Karolinska Institutet, Center for Molecular Medicine, Karolinska University Hospital, 171 76 Stockholm, Sweden
| | - Ewoud Ewing
- Department of Clinical Neuroscience, Karolinska Institutet, Center for Molecular Medicine, Karolinska University Hospital, 171 76 Stockholm, Sweden
| | - Sabrina Ruhrmann
- Department of Clinical Neuroscience, Karolinska Institutet, Center for Molecular Medicine, Karolinska University Hospital, 171 76 Stockholm, Sweden
| | - Erik Nutma
- Department of Pathology, Amsterdam UMC, Location VUmc, De Boelelaan 1117, 1081 HV Amsterdam, Netherlands
| | - Roham Parsa
- Department of Clinical Neuroscience, Karolinska Institutet, Center for Molecular Medicine, Karolinska University Hospital, 171 76 Stockholm, Sweden
| | - Melanie Thessen-Hedreul
- Department of Clinical Neuroscience, Karolinska Institutet, Center for Molecular Medicine, Karolinska University Hospital, 171 76 Stockholm, Sweden
| | - Sandra Amor
- Department of Pathology, Amsterdam UMC, Location VUmc, De Boelelaan 1117, 1081 HV Amsterdam, Netherlands.,Centre for Neuroscience and Trauma, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Robert A Harris
- Department of Clinical Neuroscience, Karolinska Institutet, Center for Molecular Medicine, Karolinska University Hospital, 171 76 Stockholm, Sweden
| | - Tomas Olsson
- Department of Clinical Neuroscience, Karolinska Institutet, Center for Molecular Medicine, Karolinska University Hospital, 171 76 Stockholm, Sweden
| | - Maja Jagodic
- Department of Clinical Neuroscience, Karolinska Institutet, Center for Molecular Medicine, Karolinska University Hospital, 171 76 Stockholm, Sweden.
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Feng S, Dang S, Han TW, Ye W, Jin P, Cheng T, Li J, Jan YN, Jan LY, Cheng Y. Cryo-EM Studies of TMEM16F Calcium-Activated Ion Channel Suggest Features Important for Lipid Scrambling. Cell Rep 2020; 28:567-579.e4. [PMID: 31291589 PMCID: PMC6684876 DOI: 10.1016/j.celrep.2019.06.023] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Revised: 05/03/2019] [Accepted: 06/05/2019] [Indexed: 12/25/2022] Open
Abstract
As a Ca2+-activated lipid scramblase and ion channel that mediates Ca2+ influx, TMEM16F relies on both functions to facilitate extracellular vesicle generation, blood coagulation, and bone formation. How a bona fide ion channel scrambles lipids remains elusive. Our structural analyses revealed the coexistence of an intact channel pore and PIP2-dependent protein conformation changes leading to membrane distortion. Correlated to the extent of membrane distortion, many tightly bound lipids are slanted. Structure-based mutagenesis studies further reveal that neutralization of some lipid-binding residues or those near membrane distortion specifically alters the onset of lipid scrambling, but not Ca2+ influx, thus identifying features outside of channel pore that are important for lipid scrambling. Together, our studies demonstrate that membrane distortion does not require open hydrophilic grooves facing the membrane interior and provide further evidence to suggest separate pathways for lipid scrambling and ion permeation. TMEM16F is a calcium-activated ion channel and lipid scramblase linked to the bleeding disorder Scott syndrome. Feng et al. examine cryo-EM structures of TMEM16F with or without Ca2+ ions and PIP2 nanodisc supplementation and identify structural features for lipid binding and membrane distortion critical for lipid scrambling activity.
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Affiliation(s)
- Shengjie Feng
- Department of Physiology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Shangyu Dang
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Tina Wei Han
- Department of Physiology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Wenlei Ye
- Department of Physiology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Peng Jin
- Department of Physiology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Tong Cheng
- Department of Physiology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Junrui Li
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Yuh Nung Jan
- Department of Physiology, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Lily Yeh Jan
- Department of Physiology, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA.
| | - Yifan Cheng
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA.
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Zhang Y, Li H, Li X, Wu J, Xue T, Wu J, Shen H, Li X, Shen M, Chen G. TMEM16F Aggravates Neuronal Loss by Mediating Microglial Phagocytosis of Neurons in a Rat Experimental Cerebral Ischemia and Reperfusion Model. Front Immunol 2020; 11:1144. [PMID: 32733436 PMCID: PMC7359929 DOI: 10.3389/fimmu.2020.01144] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 05/11/2020] [Indexed: 12/20/2022] Open
Abstract
Cerebral ischemia is a severe, acute condition, normally caused by cerebrovascular disease, and results in high rates of disability, and death. Phagoptosis is a newly recognized form of cell death caused by phagocytosis of viable cells, and has been reported to contribute to neuronal loss in brain tissue after ischemic stroke. Previous data indicated that exposure of phosphatidylserine to viable neurons could induce microglial phagocytosis of such neurons. Phosphatidylserine can be reversibly exposed to viable cells as a result of a calcium-activated phospholipid scramblase named TMEM16F. TMEM16F-mediated phospholipid scrambling on platelet membranes is critical for hemostasis and thrombosis, which plays an important role in Scott syndrome and has been confirmed by much research. However, few studies have investigated the association between TMEM16F and phagocytosis in ischemic stroke. In this study, a middle-cerebral-artery occlusion/reperfusion (MCAO/R) model was used in adult male Sprague-Dawley rats in vivo, and cultured neurons were exposed to oxygen-glucose deprivation/reoxygenation (OGD/R) to simulate cerebral ischemia-reperfusion (I/R) injury in vitro. We found that the protein level of TMEM16F was significantly increased at 12 h after I-R injury both in vivo and in vitro, and reversible phosphatidylserine exposure was confirmed in neurons undergoing I/R injury in vitro. Additionally, we constructed a LV-TMEM16F-RNAi transfection system to suppress the expression of TMEM16F during and after cerebral ischemia. As a result, TMEM16F knockdown alleviated motor function injury and decreased the microglial phagocytosis of viable neurons in the penumbra through inhibiting the “eat-me” signal phosphatidylserine. Our data indicate that reducing neuronal phosphatidylserine-exposure via deficiency of TMEM16F blocks phagocytosis of neurons and rescues stressed-but-still-viable neurons in the penumbra, which may contribute to reducing infarct volume and improving functional recovering.
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Affiliation(s)
- Yijie Zhang
- Brain and Nerve Research Laboratory, Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Haiying Li
- Brain and Nerve Research Laboratory, Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Xiang Li
- Brain and Nerve Research Laboratory, Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Jie Wu
- Brain and Nerve Research Laboratory, Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Tao Xue
- Brain and Nerve Research Laboratory, Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Jiang Wu
- Brain and Nerve Research Laboratory, Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Haitao Shen
- Brain and Nerve Research Laboratory, Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Xiang Li
- Brain and Nerve Research Laboratory, Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Meifen Shen
- Brain and Nerve Research Laboratory, Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Gang Chen
- Brain and Nerve Research Laboratory, Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, China
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30
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Ward H, West SJ. Microglia: sculptors of neuropathic pain? ROYAL SOCIETY OPEN SCIENCE 2020; 7:200260. [PMID: 32742693 PMCID: PMC7353970 DOI: 10.1098/rsos.200260] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 06/01/2020] [Indexed: 05/02/2023]
Abstract
Neuropathic pain presents a huge societal and individual burden. The limited efficacy of current analgesics, diagnostic markers and clinical trial outcome measures arises from an incomplete understanding of the underlying mechanisms. A large and growing body of evidence has established the important role of microglia in the onset and possible maintenance of neuropathic pain, and these cells may represent an important target for future therapy. Microglial research has further revealed their important role in structural remodelling of the nervous system. In this review, we aim to explore the evidence for microglia in sculpting nervous system structure and function, as well as their important role in neuropathic pain, and finally integrate these studies to synthesize a new model for microglia in somatosensory circuit remodelling, composed of six key and inter-related mechanisms. Summarizing the mechanisms through which microglia modulate nervous system structure and function helps to frame a better understanding of neuropathic pain, and provide a clear roadmap for future research.
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Affiliation(s)
- Harry Ward
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Steven J. West
- Sainsbury Wellcome Centre, University College London, 25 Howland St, London WC1E 6BT, UK
- Author for correspondence: Steven J. West e-mail:
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31
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Wu N, Cernysiov V, Davidson D, Song H, Tang J, Luo S, Lu Y, Qian J, Gyurova IE, Waggoner SN, Trinh VQH, Cayrol R, Sugiura A, McBride HM, Daudelin JF, Labrecque N, Veillette A. Critical Role of Lipid Scramblase TMEM16F in Phosphatidylserine Exposure and Repair of Plasma Membrane after Pore Formation. Cell Rep 2020; 30:1129-1140.e5. [PMID: 31995754 PMCID: PMC7104872 DOI: 10.1016/j.celrep.2019.12.066] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 10/25/2019] [Accepted: 12/17/2019] [Indexed: 01/01/2023] Open
Abstract
Plasma membrane damage and cell death during processes such as necroptosis and apoptosis result from cues originating intracellularly. However, death caused by pore-forming agents, like bacterial toxins or complement, is due to direct external injury to the plasma membrane. To prevent death, the plasma membrane has an intrinsic repair ability. Here, we found that repair triggered by pore-forming agents involved TMEM16F, a calcium-activated lipid scramblase also mutated in Scott's syndrome. Upon pore formation and the subsequent influx of intracellular calcium, TMEM16F induced rapid "lipid scrambling" in the plasma membrane. This response was accompanied by membrane blebbing, extracellular vesicle release, preserved membrane integrity, and increased cell viability. TMEM16F-deficient mice exhibited compromised control of infection by Listeria monocytogenes associated with a greater sensitivity of neutrophils to the pore-forming Listeria toxin listeriolysin O (LLO). Thus, the lipid scramblase TMEM16F is critical for plasma membrane repair after injury by pore-forming agents.
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Affiliation(s)
- Ning Wu
- Laboratory of Molecular Oncology, Institut de Recherches Cliniques de Montréal (IRCM), Montréal, QC H2W1R7, Canada; Department of Immunology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, China; Department of Rheumatology and Immunology, Tongji Hospital, Huazhong University of Science and Technology (HUST), Wuhan, China.
| | - Vitalij Cernysiov
- Laboratory of Molecular Oncology, Institut de Recherches Cliniques de Montréal (IRCM), Montréal, QC H2W1R7, Canada
| | - Dominique Davidson
- Laboratory of Molecular Oncology, Institut de Recherches Cliniques de Montréal (IRCM), Montréal, QC H2W1R7, Canada
| | - Hua Song
- Department of Immunology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, China
| | - Jianlong Tang
- Department of Immunology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, China
| | - Shanshan Luo
- Institute of Hematology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, China
| | - Yan Lu
- Laboratory of Molecular Oncology, Institut de Recherches Cliniques de Montréal (IRCM), Montréal, QC H2W1R7, Canada
| | - Jin Qian
- Laboratory of Molecular Oncology, Institut de Recherches Cliniques de Montréal (IRCM), Montréal, QC H2W1R7, Canada
| | - Ivayla E Gyurova
- Center for Autoimmune Genomics and Etiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA; Pathobiology and Molecular Medicine Graduate Program, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Stephen N Waggoner
- Center for Autoimmune Genomics and Etiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA; Pathobiology and Molecular Medicine Graduate Program, University of Cincinnati College of Medicine, Cincinnati, OH, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Vincent Quoc-Huy Trinh
- Department of Pathology and Cellular Biology, University of Montreal, Montreal, QC, Canada
| | - Romain Cayrol
- Department of Pathology and Cellular Biology, University of Montreal, Montreal, QC, Canada
| | - Ayumu Sugiura
- Montreal Neurological Institute, McGill University, Montreal, QC H3A 2B4, Canada
| | - Heidi M McBride
- Montreal Neurological Institute, McGill University, Montreal, QC H3A 2B4, Canada
| | | | - Nathalie Labrecque
- Maisonneuve-Rosemont Hospital Research Center, Montréal, QC, Canada; Department of Medicine, University of Montréal, Montréal, QC H3C3J7, Canada; Department of Microbiology, Infectious Diseases and Immunology, University of Montréal, Montréal, QC H3C3J7, Canada
| | - André Veillette
- Laboratory of Molecular Oncology, Institut de Recherches Cliniques de Montréal (IRCM), Montréal, QC H2W1R7, Canada; Maisonneuve-Rosemont Hospital Research Center, Montréal, QC, Canada; Department of Medicine, McGill University, Montréal, QC H3G 1Y6, Canada.
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32
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What Do Microglia Really Do in Healthy Adult Brain? Cells 2019; 8:cells8101293. [PMID: 31652490 PMCID: PMC6829860 DOI: 10.3390/cells8101293] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 10/17/2019] [Accepted: 10/18/2019] [Indexed: 12/27/2022] Open
Abstract
Microglia originate from yolk sac-primitive macrophages and auto-proliferate into adulthood without replacement by bone marrow-derived circulating cells. In inflammation, stroke, aging, or infection, microglia have been shown to contribute to brain pathology in both deleterious and beneficial ways, which have been studied extensively. However, less is known about their role in the healthy adult brain. Astrocytes and oligodendrocytes are widely accepted to strongly contribute to the maintenance of brain homeostasis and to modulate neuronal function. On the other hand, contribution of microglia to cognition and behavior is only beginning to be understood. The ability to probe their function has become possible using microglial depletion assays and conditional mutants. Studies have shown that the absence of microglia results in cognitive and learning deficits in rodents during development, but this effect is less pronounced in adults. However, evidence suggests that microglia play a role in cognition and learning in adulthood and, at a cellular level, may modulate adult neurogenesis. This review presents the case for repositioning microglia as key contributors to the maintenance of homeostasis and cognitive processes in the healthy adult brain, in addition to their classical role as sentinels coordinating the neuroinflammatory response to tissue damage and disease.
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Zhao J, Gao QY. TMEM16F inhibition limits pain-associated behavior and improves motor function by promoting microglia M2 polarization in mice. Biochem Biophys Res Commun 2019; 517:603-610. [PMID: 31409484 DOI: 10.1016/j.bbrc.2019.07.070] [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: 07/12/2019] [Accepted: 07/19/2019] [Indexed: 12/15/2022]
Abstract
Spinal cord injury (SCI) leads to sensorimotor deficits and autonomic changes. Macrophages and microglia could be polarized into the classically activated pro-inflammatory M1 phenotype or the alternatively activated anti-inflammatory M2 phenotype. Transmembrane protein with unknown function 16F (TMEM16F) exhibits functional diversity and may contribute to microglial function. However, the effects of TMEM16F on the modulation of macrophage/microglial polarization are still not fully understood. In the study, TMEM16F up-regulation was detected after SCI in mice, and TMEM16F protein was found in macrophages/microglia in injured spinal cord sections. Depletion of TMEM16F improved motor function in male mice with SCI. M1-type macrophages/microglia accumulated in lower numbers in the injured spinal cord of TMEM16F-knockout (KO) mice. M2 polarization inhibited by SCI was improved in mice with TMEM16F deficiency. TMEM16F deletion also attenuated microglial/macrophage pro-inflammatory response. Furthermore, significant down-regulation of A disintegrin and metalloprotease 17 (ADAM17) was observed in TMEM16F-KO mice. Importantly, TMEM16F-promoted M1 polarization and -inhibited M1 polarization were largely associated with the suppression of ADAM17. Overall, our findings provided new insights into the regulatory mechanisms of macrophage/microglial polarization, thereby possibly facilitating the development of new therapeutic strategies for SCI through the regulation of TMEM16F/ADAM17 signaling.
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Affiliation(s)
- Jing Zhao
- Department of Orthopedics Spinal Ward, Xi'an Hospital of Traditional Chinese Medicine, Xi'an City, Shaanxi Province, 710021, China
| | - Quan-You Gao
- Department of Orthopaedics, Tangdu Hospital Second Affiliated Hospital of Air Force Military Medical University, Xi'an City, Shaanxi Province, 710038, China.
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34
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Chen G, Zhang YQ, Qadri YJ, Serhan CN, Ji RR. Microglia in Pain: Detrimental and Protective Roles in Pathogenesis and Resolution of Pain. Neuron 2019; 100:1292-1311. [PMID: 30571942 DOI: 10.1016/j.neuron.2018.11.009] [Citation(s) in RCA: 466] [Impact Index Per Article: 93.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Revised: 10/22/2018] [Accepted: 11/02/2018] [Indexed: 12/18/2022]
Abstract
The previous decade has seen a rapid increase in microglial studies on pain, with a unique focus on microgliosis in the spinal cord after nerve injury and neuropathic pain. Numerous signaling molecules are altered in microglia and contribute to the pathogenesis of pain. Here, we discuss how microglial signaling regulates spinal cord synaptic plasticity in acute and chronic pain conditions with different degrees and variations of microgliosis. We highlight that microglial mediators such as pro- and anti-inflammatory cytokines are powerful neuromodulators that regulate synaptic transmission and pain via neuron-glial interactions. We also reveal an emerging role of microglia in the resolution of pain, in part via specialized pro-resolving mediators including resolvins, protectins, and maresins. We also discuss a possible role of microglia in chronic itch.
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Affiliation(s)
- Gang Chen
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, China
| | - Yu-Qiu Zhang
- Institute of Neurobiology, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Collaborative Innovation Center for Brain Science, Fudan University, Shanghai 200032, China
| | - Yawar J Qadri
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Charles N Serhan
- Center for Experimental Therapeutics and Reperfusion Injury, Hale Transformative Medicine, Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Ru-Rong Ji
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA; Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA.
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35
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Cowie AM, Dittel BN, Stucky CL. A Novel Sex-Dependent Target for the Treatment of Postoperative Pain: The NLRP3 Inflammasome. Front Neurol 2019; 10:622. [PMID: 31244767 PMCID: PMC6581722 DOI: 10.3389/fneur.2019.00622] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 05/28/2019] [Indexed: 12/11/2022] Open
Abstract
In recent years the innate immune system has been shown to be crucial for the pathogenesis of postoperative pain. The mediators released by innate immune cells drive the sensitization of sensory neurons following injury by directly acting on peripheral nerve terminals at the injury site. The predominate sensitization signaling pathway involves the proinflammatory cytokine interleukin-1β (IL-1β). IL-1β is known to cause pain by directly acting on sensory neurons. Evidence demonstrates that blockade of IL-1β signaling decreases postoperative pain, however complete blockade of IL-1β signaling increases the risk of infection and decreases effective wound healing. IL-1β requires activation by an inflammasome; inflammasomes are cytosolic receptors of the innate immune system. NOD-like receptor protein 3 (NLRP3) is the predominant inflammasome activated by endogenous molecules that are released by tissue injury such as that which occurs during neuropathic and inflammatory pain disorders. Given that selective inhibition of NLRP3 alleviates postoperative mechanical pain, its selective targeting may be a novel and effective strategy for the treatment of pain that would avoid complications of global IL-1β inhibition. Moreover, NLRP3 is activated in pain in a sex-dependent and cell type-dependent manner. Sex differences in the innate immune system have been shown to drive pain and sensitization through different mechanisms in inflammatory and neuropathic pain disorders, indicating that it is imperative that both sexes are studied when researchers investigate and identify new targets for pain therapeutics. This review will highlight the roles of the innate immune response, the NLRP3 inflammasome, and sex differences in neuropathic and inflammatory pain.
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Affiliation(s)
- Ashley M Cowie
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Bonnie N Dittel
- Blood Research Institute, Versiti, Milwaukee, WI, United States.,Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Cheryl L Stucky
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI, United States
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Bricogne C, Fine M, Pereira PM, Sung J, Tijani M, Wang Y, Henriques R, Collins MK, Hilgemann DW. TMEM16F activation by Ca 2+ triggers plasma membrane expansion and directs PD-1 trafficking. Sci Rep 2019; 9:619. [PMID: 30679690 PMCID: PMC6345885 DOI: 10.1038/s41598-018-37056-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 12/03/2018] [Indexed: 12/22/2022] Open
Abstract
TMEM16F is a Ca2+ -gated ion channel that is required for Ca2+ -activated phosphatidylserine exposure on the surface of many eukaryotic cells. TMEM16F is widely expressed and has roles in platelet activation during blood clotting, bone formation and T cell activation. By combining microscopy and patch clamp recording we demonstrate that activation of TMEM16F by Ca2+ ionophores in Jurkat T cells triggers large-scale surface membrane expansion in parallel with phospholipid scrambling. With continued ionophore application,TMEM16F-expressing cells then undergo extensive shedding of ectosomes. The T cell co-receptor PD-1 is selectively incorporated into ectosomes. This selectivity depends on its transmembrane sequence. Surprisingly, cells lacking TMEM16F not only fail to expand surface membrane in response to elevated cytoplasmic Ca2+, but instead undergo rapid massive endocytosis with PD-1 internalisation. These results establish a new role for TMEM16F as a regulator of Ca2+ activated membrane trafficking.
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Affiliation(s)
| | - Michael Fine
- University of Texas Southwestern Medical Center, Department of Physiology, Dallas, Texas, USA
| | - Pedro M Pereira
- MRC Laboratory for Molecular Cell Biology, University College London, Gower St, London, UK
| | - Julia Sung
- National Institute for Biological Standards and Control, Blanche Lane, South Mimms, Herts, UK
| | - Maha Tijani
- National Institute for Biological Standards and Control, Blanche Lane, South Mimms, Herts, UK
| | - Youxue Wang
- University of Texas Southwestern Medical Center, Department of Physiology, Dallas, Texas, USA
| | - Ricardo Henriques
- MRC Laboratory for Molecular Cell Biology, University College London, Gower St, London, UK
| | - Mary K Collins
- UCL Cancer Institute, University College London, Gower St, London, UK.
- National Institute for Biological Standards and Control, Blanche Lane, South Mimms, Herts, UK.
- Okinawa Institute of Science and Technology, Onna-son, Okinawa, Japan.
| | - Donald W Hilgemann
- University of Texas Southwestern Medical Center, Department of Physiology, Dallas, Texas, USA.
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Kohno K, Kitano J, Kohro Y, Tozaki-Saitoh H, Inoue K, Tsuda M. Temporal Kinetics of Microgliosis in the Spinal Dorsal Horn after Peripheral Nerve Injury in Rodents. Biol Pharm Bull 2018; 41:1096-1102. [DOI: 10.1248/bpb.b18-00278] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Keita Kohno
- Department of Life Innovation, Graduate School of Pharmaceutical Sciences, Kyushu University
| | - Junko Kitano
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University
| | - Yuta Kohro
- Department of Life Innovation, Graduate School of Pharmaceutical Sciences, Kyushu University
| | - Hidetoshi Tozaki-Saitoh
- Department of Life Innovation, Graduate School of Pharmaceutical Sciences, Kyushu University
| | - Kazuhide Inoue
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University
| | - Makoto Tsuda
- Department of Life Innovation, Graduate School of Pharmaceutical Sciences, Kyushu University
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38
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Falzone ME, Malvezzi M, Lee BC, Accardi A. Known structures and unknown mechanisms of TMEM16 scramblases and channels. J Gen Physiol 2018; 150:933-947. [PMID: 29915161 PMCID: PMC6028493 DOI: 10.1085/jgp.201711957] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 05/29/2018] [Indexed: 12/25/2022] Open
Abstract
Falzone et al. interpret the mechanisms underlying the activity of TMEM16 family members from recent structural and functional work. The TMEM16 family of membrane proteins is composed of both Ca2+-gated Cl− channels and Ca2+-dependent phospholipid scramblases. The functional diversity of TMEM16s underlies their involvement in numerous signal transduction pathways that connect changes in cytosolic Ca2+ levels to cellular signaling networks. Indeed, defects in the function of several TMEM16s cause a variety of genetic disorders, highlighting their fundamental pathophysiological importance. Here, we review how our mechanistic understanding of TMEM16 function has been shaped by recent functional and structural work. Remarkably, the recent determination of near-atomic-resolution structures of TMEM16 proteins of both functional persuasions has revealed how relatively minimal rearrangements in the substrate translocation pathway are sufficient to precipitate the dramatic functional differences that characterize the family. These structures, when interpreted in the light of extensive functional analysis, point to an unusual mechanism for Ca2+-dependent activation of TMEM16 proteins in which substrate permeation is regulated by a combination of conformational rearrangements and electrostatics. These breakthroughs pave the way to elucidate the mechanistic bases of ion and lipid transport by the TMEM16 proteins and unravel the molecular links between these transport activities and their function in human pathophysiology.
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Affiliation(s)
- Maria E Falzone
- Department of Biochemistry, Weill Cornell Medical School, New York, NY
| | - Mattia Malvezzi
- Department of Anesthesiology, Weill Cornell Medical School, New York, NY
| | - Byoung-Cheol Lee
- Department of Anesthesiology, Weill Cornell Medical School, New York, NY
| | - Alessio Accardi
- Department of Biochemistry, Weill Cornell Medical School, New York, NY .,Department of Anesthesiology, Weill Cornell Medical School, New York, NY.,Department of Physiology, Biophysics and Systems Biology, Weill Cornell Medical School, New York, NY
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39
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Microglia in neuropathic pain: cellular and molecular mechanisms and therapeutic potential. Nat Rev Neurosci 2018; 19:138-152. [DOI: 10.1038/nrn.2018.2] [Citation(s) in RCA: 365] [Impact Index Per Article: 60.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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40
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Abstract
The Cre/loxP system is a widely applied technology for site-specific genetic manipulation in mice. This system allows for deletion of the genes of interest in specific cells, tissues, and whole organism to generate a diversity of conditional knockout mouse strains. Additionally, the Cre/loxP system is useful for development of cell- and tissue-specific reporter mice for lineage tracing, and cell-specific conditional depletion models in mice. Recently, the Cre/loxP technique was extensively adopted to characterize the monocyte/macrophage biology in mouse models. Compared to other relatively homogenous immune cell types such as neutrophils, mast cells, and basophils, monocytes/macrophages represent a highly heterogeneous population which lack specific markers or transcriptional factors. Though great efforts have been made toward establishing macrophage-specific Cre driver mice in the past decade, all of the current available strains are not perfect with regard to their depletion efficiency and targeting specificity for endogenous macrophages. Here we overview the commonly used Cre driver mouse strains targeting macrophages and discuss their major applications and limitations.
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Paris I, Savage JC, Escobar L, Abiega O, Gagnon S, Hui CW, Tremblay MÈ, Sierra A, Valero J. ProMoIJ: A new tool for automatic three-dimensional analysis of microglial process motility. Glia 2017; 66:828-845. [PMID: 29288586 DOI: 10.1002/glia.23287] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 11/28/2017] [Accepted: 12/11/2017] [Indexed: 12/31/2022]
Abstract
Microglia, the immune cells of the central nervous system, continuously survey the brain to detect alterations and maintain tissue homeostasis. The motility of microglial processes is indicative of their surveying capacity in normal and pathological conditions. The gold standard technique to study motility involves the use of two-photon microscopy to obtain time-lapse images from brain slices or the cortex of living animals. This technique generates four dimensionally-coded images which are analyzed manually using time-consuming, non-standardized protocols. Microglial process motility analysis is frequently performed using Z-stack projections with the consequent loss of three-dimensional (3D) information. To overcome these limitations, we developed ProMoIJ, a pack of ImageJ macros that perform automatic motility analysis of cellular processes in 3D. The main core of ProMoIJ is formed by two macros that assist the selection of processes, automatically reconstruct their 3D skeleton, and analyze their motility (process and tip velocity). Our results show that ProMoIJ presents several key advantages compared with conventional manual analysis: (1) reduces the time required for analysis, (2) is less sensitive to experimenter bias, and (3) is more robust to varying numbers of processes analyzed. In addition, we used ProMoIJ to demonstrate that commonly performed 2D analysis underestimates microglial process motility, to reveal that only cells adjacent to a laser injured area extend their processes toward the lesion site, and to demonstrate that systemic inflammation reduces microglial process motility. ProMoIJ is a novel, open-source, freely-available tool which standardizes and accelerates the time-consuming labor of 3D analysis of microglial process motility.
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Affiliation(s)
- Iñaki Paris
- Achucarro Basque Center for Neuroscience, Science Park of the UPV/EHU, Leioa, Bizkaia, Spain
| | - Julie C Savage
- Centre de recherche du CHU de Québec, Axe Neurosciences, Québec, Canada.,Département de médecine moléculaire, Université Laval, Québec, Canada
| | - Laura Escobar
- Achucarro Basque Center for Neuroscience, Science Park of the UPV/EHU, Leioa, Bizkaia, Spain
| | - Oihane Abiega
- Achucarro Basque Center for Neuroscience, Science Park of the UPV/EHU, Leioa, Bizkaia, Spain.,Ikerbasque Basque Foundation for Science, Bilbao, Bizkaia, Spain
| | - Steven Gagnon
- Centre de recherche du CHU de Québec, Axe Neurosciences, Québec, Canada.,Département de médecine moléculaire, Université Laval, Québec, Canada
| | - Chin-Wai Hui
- Centre de recherche du CHU de Québec, Axe Neurosciences, Québec, Canada.,Département de médecine moléculaire, Université Laval, Québec, Canada
| | - Marie-Ève Tremblay
- Centre de recherche du CHU de Québec, Axe Neurosciences, Québec, Canada.,Département de médecine moléculaire, Université Laval, Québec, Canada
| | - Amanda Sierra
- Achucarro Basque Center for Neuroscience, Science Park of the UPV/EHU, Leioa, Bizkaia, Spain.,Ikerbasque Basque Foundation for Science, Bilbao, Bizkaia, Spain.,University of the Basque Country, Leioa, Bizkaia, Spain
| | - Jorge Valero
- Achucarro Basque Center for Neuroscience, Science Park of the UPV/EHU, Leioa, Bizkaia, Spain.,Ikerbasque Basque Foundation for Science, Bilbao, Bizkaia, Spain
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Secreted Phospholipases A₂ from Animal Venoms in Pain and Analgesia. Toxins (Basel) 2017; 9:toxins9120406. [PMID: 29311537 PMCID: PMC5744126 DOI: 10.3390/toxins9120406] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 12/13/2017] [Accepted: 12/16/2017] [Indexed: 12/20/2022] Open
Abstract
Animal venoms comprise a complex mixture of components that affect several biological systems. Based on the high selectivity for their molecular targets, these components are also a rich source of potential therapeutic agents. Among the main components of animal venoms are the secreted phospholipases A2 (sPLA2s). These PLA2 belong to distinct PLA2s groups. For example, snake venom sPLA2s from Elapidae and Viperidae families, the most important families when considering envenomation, belong, respectively, to the IA and IIA/IIB groups, whereas bee venom PLA2 belongs to group III of sPLA2s. It is well known that PLA2, due to its hydrolytic activity on phospholipids, takes part in many pathophysiological processes, including inflammation and pain. Therefore, secreted PLA2s obtained from animal venoms have been widely used as tools to (a) modulate inflammation and pain, uncovering molecular targets that are implicated in the control of inflammatory (including painful) and neurodegenerative diseases; (b) shed light on the pathophysiology of inflammation and pain observed in human envenomation by poisonous animals; and, (c) characterize molecular mechanisms involved in inflammatory diseases. The present review summarizes the knowledge on the nociceptive and antinociceptive actions of sPLA2s from animal venoms, particularly snake venoms.
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Abstract
One of the fundamental mechanisms whereby the innate immune system coordinates inflammatory signal transduction is through Toll-like receptors (TLRs), which function to protect and defend the host organism by initiating inflammatory signaling cascades in response to tissue damage or injury. TLRs are positioned at the neuroimmune interface, and accumulating evidence suggests that the inflammatory consequences of TLR activation on glia (including microglia and astrocytes), sensory neurons, and other cell types can influence nociceptive processing and lead to states of exaggerated and unresolved pain. In this review, we summarize our current understanding of how different TLRs and their accessory or adaptor molecules can contribute to the development and maintenance of persistent pain. The challenges and opportunities of targeting TLRs for new treatment strategies against chronic pain are discussed, including the therapeutic context of TLR-mediated signaling in opioid analgesia and chemotherapy-induced pain. Considering the prevalence of persistent pain and the insufficient efficacy and safety of current treatment options, a deeper understanding of Toll-like receptors holds the promise of novel therapies for managing pathological pain.
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Machelska H, Celik MÖ. Recent advances in understanding neuropathic pain: glia, sex differences, and epigenetics. F1000Res 2016; 5:2743. [PMID: 28105313 PMCID: PMC5224690 DOI: 10.12688/f1000research.9621.1] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/14/2016] [Indexed: 12/17/2022] Open
Abstract
Neuropathic pain results from diseases or trauma affecting the nervous system. This pain can be devastating and is poorly controlled. The pathophysiology is complex, and it is essential to understand the underlying mechanisms in order to identify the relevant targets for therapeutic intervention. In this article, we focus on the recent research investigating neuro-immune communication and epigenetic processes, which gain particular attention in the context of neuropathic pain. Specifically, we analyze the role of glial cells, including microglia, astrocytes, and oligodendrocytes, in the modulation of the central nervous system inflammation triggered by neuropathy. Considering epigenetics, we address DNA methylation, histone modifications, and the non-coding RNAs in the regulation of ion channels, G-protein-coupled receptors, and transmitters following neuronal damage. The goal was not only to highlight the emerging concepts but also to discuss controversies, methodological complications, and intriguing opinions.
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Affiliation(s)
- Halina Machelska
- Department of Anesthesiology and Critical Care Medicine, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - Melih Ö Celik
- Department of Anesthesiology and Critical Care Medicine, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
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