1
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Logan-Wesley AL, Gorse KM, Lafrenaye AD. Microglial process convergence onto injured axonal swellings, a human postmortem brain tissue study. RESEARCH SQUARE 2024:rs.3.rs-4713316. [PMID: 39149456 PMCID: PMC11326398 DOI: 10.21203/rs.3.rs-4713316/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/17/2024]
Abstract
Traumatic brain injury (TBI) affects millions globally, with a majority of TBI cases being classified as mild, in which diffuse pathologies prevail. Two of the pathological hallmarks of TBI are diffuse axonal injury and microglial activation. While progress has been made investigating the breadth of TBI-induced axonal injury and microglial changes in rodents, the neuroinflammatory progression and interaction between microglia and injured axons following brain injury in humans is less well understood. Our group previously investigated microglial process convergence (MPC), in which processes of non-phagocytic microglia directly contact injured proximal axonal segments, in rats and micropigs acutely following TBI. These studies demonstrated that MPC occurred on injured axons in the micropig, but not in the rat, following diffuse TBI. While it has been shown that microglia co-exist and interact with injured axons in humans post-TBI, the occurrence of MPC has not been quantitatively measured in the human brain. Therefore, in the current study we sought to validate our pig findings in human postmortem tissue. We investigated MPC onto injured axonal swellings and intact myelinated fibers in cases from individuals that sustained a TBI and control human brain tissue using multiplex immunofluorescent histochemistry. We found an increase in MPC onto injured axonal swellings, consistent with our previous findings in micropigs, indicating that MPC is a clinically relevant phenomenon that warrants further investigation.
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2
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Implications of microglial heterogeneity in spinal cord injury progression and therapy. Exp Neurol 2023; 359:114239. [PMID: 36216123 DOI: 10.1016/j.expneurol.2022.114239] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Revised: 09/21/2022] [Accepted: 10/03/2022] [Indexed: 11/07/2022]
Abstract
Microglia are widely distributed in the central nervous system (CNS), where they aid in the maintenance of neuronal function and perform key auxiliary roles in phagocytosis, neural repair, immunological control, and nutrition delivery. Microglia in the undamaged spinal cord is in a stable state and serve as immune monitors. In the event of spinal cord injury (SCI), severe changes in the microenvironment and glial scar formation lead to axonal regeneration failure. Microglia participates in a series of pathophysiological processes and behave both positive and negative consequences during this period. A deep understanding of the characteristics and functions of microglia can better identify therapeutic targets for SCI. Technological innovations such as single-cell RNA sequencing (Sc-RNAseq) have led to new advances in the study of microglia heterogeneity throughout the lifespan. Here,We review the updated studies searching for heterogeneity of microglia from the developmental and pathological state, survey the activity and function of microglia in SCI and explore the recent therapeutic strategies targeting microglia in the CNS injury.
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3
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Xu L, Wang J, Ding Y, Wang L, Zhu YJ. Current Knowledge of Microglia in Traumatic Spinal Cord Injury. Front Neurol 2022; 12:796704. [PMID: 35087472 PMCID: PMC8787368 DOI: 10.3389/fneur.2021.796704] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Accepted: 12/07/2021] [Indexed: 12/12/2022] Open
Abstract
Microglia are the resident immune cells in the central nervous system (CNS). After traumatic spinal cord injury (SCI), microglia undergo activation, proliferation, and changes in gene and protein expression and morphology, with detrimental and beneficial effects. Activated microglia cause secondary neuronal injury via the production of proinflammatory cytokines, reactive oxygen species, and proteases. However, activated microglia also promote neuronal repair through the secretion of anti-inflammatory growth factors and cytokines. Proinflammatory cytokines increase endothelial permeability, promote A1 astrocyte activation and axonal demyelination, and reduce neural stem/progenitor cells (NSPCs), leading to the exacerbation of neuronal injury. In contrast, anti-inflammatory factors facilitate angiogenesis, reduce reactive astrocytes, and promote axonal remyelination and the propagation of NSPCs, contributing to tissue repair and locomotor recovery. Due to its limited regenerative capacity, the CNS requires beneficial microglia for continuous protection against injury. Understanding and regulating microglial activation status are beneficial to reducing detrimental effects and promoting repair behaviors and to obtain more information on efficient therapies for traumatic SCI. This review discusses microglial activation and the differences between microglia and similar immune cells, microglial interactions with other cells in the spinal cord, and the progress in the development of therapies targeting microglia in SCI.
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Affiliation(s)
- Lintao Xu
- Department of Neurosurgery, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Jingyu Wang
- Department of Neurosurgery, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Yueming Ding
- School of Medicine, Zhejiang University City College, Hangzhou, China
| | - Linlin Wang
- Department of Basic Medicine Sciences, and Department of Orthopaedics of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yong-Jian Zhu
- Department of Neurosurgery, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
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4
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Wofford KL, Grovola MR, Adewole DO, Browne KD, Putt ME, O’Donnell JC, Cullen DK. Relationships between injury kinematics, neurological recovery, and pathology following concussion. Brain Commun 2021; 3:fcab268. [PMID: 34934944 PMCID: PMC8684470 DOI: 10.1093/braincomms/fcab268] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 06/21/2021] [Accepted: 07/01/2021] [Indexed: 11/12/2022] Open
Abstract
Mild traumatic brain injury affects millions of individuals annually primarily through falls, traffic collisions, or blunt trauma and can generate symptoms that persist for years. Closed-head rotational loading is the most common cause of mild traumatic brain injury and is defined by a rapid rotational acceleration of brain tissue within an intact skull. Injury kinematics-the mechanical descriptors of injury-inducing motion-explain movement of the head, which govern energy transfer, and, therefore, determine injury severity. However, the relationship between closed-head rotational injury kinematics-such as angular velocity, angular acceleration, and injury duration-and outcome after mild traumatic brain injury is not completely understood. To address this gap in knowledge, we analysed archived surgical records of 24 swine experiencing a diffuse closed-head rotational acceleration mild traumatic brain injury against 12 sham animals. Kinematics were contrasted against acute recovery outcomes, specifically apnea time, extubation time, standing time, and recovery duration. Compared to controls, animals experiencing a mild traumatic brain injury were far more likely to have apnea (P < 0.001), shorter time to extubation (P = 0.023), and longer time from extubation to standing (P = 0.006). Using least absolute shrinkage and selection operator-based regressions, kinematic parameters, including maximum negative angular velocity and time from peak angular velocity to maximum angular deceleration, were selected to explain variation in apnea time, standing time, and recovery duration. Simplified linear models employing the least absolute shrinkage and selection operator-selected variables explained a modest degree of variation in apnea time (adjusted R 2 = 0.18), standing time (adjusted R 2 = 0.19), and recovery duration (adjusted R 2 = 0.27). Neuropathology was correlated with multiple injury kinematics, with maximum angular acceleration exhibiting the strongest correlation (R 2 = 0.66). Together, these data suggest the interplay between multiple injury kinematics, including maximum negative angular velocity (immediately preceding cessation of head motion) and time from peak angular velocity to maximum angular deceleration, best explain acute recovery metrics and neuropathology after mild traumatic brain injury in swine. Future experiments that independently manipulate individual kinematic parameters could be instrumental in developing translational diagnostics for clinical mild traumatic brain injury.
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Affiliation(s)
- Kathryn L Wofford
- Center for Brain Injury & Repair, Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA 19104, USA
- Center for Neurotrauma, Neurodegeneration and Restoration, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA 19104, USA
| | - Michael R Grovola
- Center for Brain Injury & Repair, Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA 19104, USA
- Center for Neurotrauma, Neurodegeneration and Restoration, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA 19104, USA
| | - Dayo O Adewole
- Center for Neurotrauma, Neurodegeneration and Restoration, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA 19104, USA
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kevin D Browne
- Center for Brain Injury & Repair, Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA 19104, USA
- Center for Neurotrauma, Neurodegeneration and Restoration, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA 19104, USA
| | - Mary E Putt
- Department of Biostatistics, Epidemiology & Informatics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - John C O’Donnell
- Center for Brain Injury & Repair, Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA 19104, USA
- Center for Neurotrauma, Neurodegeneration and Restoration, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA 19104, USA
| | - D Kacy Cullen
- Center for Brain Injury & Repair, Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA 19104, USA
- Center for Neurotrauma, Neurodegeneration and Restoration, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA 19104, USA
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
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5
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Wofford KL, Grovola MR, Adewole DO, Browne KD, Putt ME, O'Donnell JC, Cullen DK. Relationships between injury kinematics, neurological recovery, and pathology following concussion. Brain Commun 2021. [PMID: 34934944 DOI: 10.1093/braincomms/fcab268/6430108] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023] Open
Abstract
Mild traumatic brain injury affects millions of individuals annually primarily through falls, traffic collisions, or blunt trauma and can generate symptoms that persist for years. Closed-head rotational loading is the most common cause of mild traumatic brain injury and is defined by a rapid rotational acceleration of brain tissue within an intact skull. Injury kinematics-the mechanical descriptors of injury-inducing motion-explain movement of the head, which govern energy transfer, and, therefore, determine injury severity. However, the relationship between closed-head rotational injury kinematics-such as angular velocity, angular acceleration, and injury duration-and outcome after mild traumatic brain injury is not completely understood. To address this gap in knowledge, we analysed archived surgical records of 24 swine experiencing a diffuse closed-head rotational acceleration mild traumatic brain injury against 12 sham animals. Kinematics were contrasted against acute recovery outcomes, specifically apnea time, extubation time, standing time, and recovery duration. Compared to controls, animals experiencing a mild traumatic brain injury were far more likely to have apnea (P < 0.001), shorter time to extubation (P = 0.023), and longer time from extubation to standing (P = 0.006). Using least absolute shrinkage and selection operator-based regressions, kinematic parameters, including maximum negative angular velocity and time from peak angular velocity to maximum angular deceleration, were selected to explain variation in apnea time, standing time, and recovery duration. Simplified linear models employing the least absolute shrinkage and selection operator-selected variables explained a modest degree of variation in apnea time (adjusted R 2 = 0.18), standing time (adjusted R 2 = 0.19), and recovery duration (adjusted R 2 = 0.27). Neuropathology was correlated with multiple injury kinematics, with maximum angular acceleration exhibiting the strongest correlation (R 2 = 0.66). Together, these data suggest the interplay between multiple injury kinematics, including maximum negative angular velocity (immediately preceding cessation of head motion) and time from peak angular velocity to maximum angular deceleration, best explain acute recovery metrics and neuropathology after mild traumatic brain injury in swine. Future experiments that independently manipulate individual kinematic parameters could be instrumental in developing translational diagnostics for clinical mild traumatic brain injury.
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Affiliation(s)
- Kathryn L Wofford
- Center for Brain Injury & Repair, Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA 19104, USA.,Center for Neurotrauma, Neurodegeneration and Restoration, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA 19104, USA
| | - Michael R Grovola
- Center for Brain Injury & Repair, Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA 19104, USA.,Center for Neurotrauma, Neurodegeneration and Restoration, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA 19104, USA
| | - Dayo O Adewole
- Center for Neurotrauma, Neurodegeneration and Restoration, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA 19104, USA.,Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kevin D Browne
- Center for Brain Injury & Repair, Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA 19104, USA.,Center for Neurotrauma, Neurodegeneration and Restoration, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA 19104, USA
| | - Mary E Putt
- Department of Biostatistics, Epidemiology & Informatics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - John C O'Donnell
- Center for Brain Injury & Repair, Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA 19104, USA.,Center for Neurotrauma, Neurodegeneration and Restoration, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA 19104, USA
| | - D Kacy Cullen
- Center for Brain Injury & Repair, Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA 19104, USA.,Center for Neurotrauma, Neurodegeneration and Restoration, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA 19104, USA.,Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
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6
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Abstract
Microglia dynamically interact with neurons influencing the development, structure, and function of neuronal networks. Recent studies suggest microglia may also influence neuronal activity by physically interacting with axonal domains responsible for action potential initiation and propagation. However, the nature of these microglial process interactions is not well understood. Microglial-axonal contacts are present early in development and persist through adulthood, implicating microglial interactions in the regulation of axonal integrity in both the developing and mature central nervous system. Moreover, changes in microglial-axonal contact have been described in disease states such as multiple sclerosis (MS) and traumatic brain injury (TBI). Depending on the disease state, there are increased associations with specific axonal segments. In MS, there is enhanced contact with the axon initial segment and node of Ranvier, while, in TBI, microglia alter interactions with axons at the site of injury, as well as at the axon initial segment. In this article, we review the interactions of microglial processes with axonal segments, analyzing their associations with various axonal domains and how these interactions may differ between MS and TBI. Furthermore, we discuss potential functional consequences and molecular mechanisms of these interactions and how these may differ among various types of microglial-axonal interactions.
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Affiliation(s)
- Savannah D Benusa
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Audrey D Lafrenaye
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA 23298, USA
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7
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Nasser M, Ballout N, Mantash S, Bejjani F, Najdi F, Ramadan N, Soueid J, Zibara K, Kobeissy F. Transplantation of Embryonic Neural Stem Cells and Differentiated Cells in a Controlled Cortical Impact (CCI) Model of Adult Mouse Somatosensory Cortex. Front Neurol 2018; 9:895. [PMID: 30405520 PMCID: PMC6208009 DOI: 10.3389/fneur.2018.00895] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 10/02/2018] [Indexed: 12/11/2022] Open
Abstract
Traumatic brain injury (TBI) is a major cause of death worldwide. Depending on the severity of the injury, TBI can reflect a broad range of consequences such as speech impairment, memory disturbances, and premature death. In this study, embryonic neural stem cells (ENSC) were isolated from E14 mouse embryos and cultured to produce neurospheres which were induced to generate differentiated cells (DC). As a cell replacement treatment option, we aimed to transplant ENSC or DC into the adult injured C57BL/6 mouse cortex controlled cortical impact (CCI) model, 7 days post-trauma, in comparison to saline injection (control). The effect of grafted cells on neuroinflammation and neurogenesis was investigated at 1 and 4 weeks post-transplantation. Results showed that microglia were activated following mild CCI, but not enhanced after engraftment of ENSC or DC. Indeed, ipsilateral lesioned somatosensory area expressed high levels of Iba-1+ microglia within the different groups after 1 and 4 weeks. On the other hand, treatment with ENSC or DC demonstrated a significant reduction in astrogliosis. The levels of GFAP expressing astrocytes started decreasing early (1 week) in the ENSC group and then were similarly low at 4 weeks in both ENSC and DC. Moreover, neurogenesis was significantly enhanced in ENSC and DC groups. Indeed, a significant increase in the number of DCX expressing progenitor cells was observed at 1 week in the ENSC group, and in DC and ENSC groups at 4 weeks. Furthermore, the number of mature neuronal cells (NeuN+) significantly increased in DC group at 4 weeks whereas they decreased in ENSC group at 1 week. Therefore, injection of ENSC or DC post-CCI caused decreased astrogliosis and suggested an increased neurogenesis via inducing neural progenitor proliferation and expression rather than neuronal maturation. Thus, ENSC may play a role in replacing lost cells and brain repair following TBI by improving neurogenesis and reducing neuroinflammation, reflecting an optimal environment for transplanted and newly born cells.
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Affiliation(s)
- Mohammad Nasser
- Biology Department, Faculty of Sciences-I, Lebanese University, Beirut, Lebanon.,ER045, PRASE, DSST, Lebanese University, Beirut, Lebanon
| | | | - Sarah Mantash
- ER045, PRASE, DSST, Lebanese University, Beirut, Lebanon
| | | | - Farah Najdi
- ER045, PRASE, DSST, Lebanese University, Beirut, Lebanon
| | - Naify Ramadan
- ER045, PRASE, DSST, Lebanese University, Beirut, Lebanon.,Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Jihane Soueid
- Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Kazem Zibara
- Biology Department, Faculty of Sciences-I, Lebanese University, Beirut, Lebanon.,ER045, PRASE, DSST, Lebanese University, Beirut, Lebanon
| | - Firas Kobeissy
- Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
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8
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Gorse KM, Lafrenaye AD. The Importance of Inter-Species Variation in Traumatic Brain Injury-Induced Alterations of Microglial-Axonal Interactions. Front Neurol 2018; 9:778. [PMID: 30294296 PMCID: PMC6158363 DOI: 10.3389/fneur.2018.00778] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 08/29/2018] [Indexed: 11/13/2022] Open
Abstract
Interactions between microglia and neuronal components are important for normal CNS function. They are also associated with neuroinflammation and many pathological processes and several studies have explored these interactions in terms of phagocytic engulfment. Much progress has also been made in understanding the consequences of chronic neuroinflammatory changes following trauma. However, little is known about acute alterations to these physical non-phagocytic microglial-neuronal interactions following traumatic brain injury (TBI), and particularly to what degree these post-injury interactions may be influenced by the animal species utilized in pre-clinical models of TBI. To investigate these problems, we evaluated the physical interactions between microglia and injured axons acutely (6 h and 1 day) following central fluid percussion injury (cFPI) in both rats and micro pigs. The physical interactions between Iba-1+ microglia and either normal MBP+ myelinated fibers or APP+ injured axonal swellings in the thalamus were assessed following injury or sham via quantitative image analysis of 3D confocal micrographs. The results indicated that the physical interactions between microglia and injured axonal swellings decreased by nearly half in rats 6 h following cFPI but was consistent with sham control at 1 day post-cFPI. This reduction was also observed in non-injured intact fibers at both timepoints following TBI in the rat. Microglial process interactions with injured axons in the micro pig, however, increased nearly 2-fold compared to interactions with intact axonal segments 1 day post-cFPI. This study shows that the species utilized for in vivo pre-clinical studies influences the manner in which microglial-axonal interactions change following TBI. These species differences can be leveraged to further our understanding of the mechanisms involved in microglial process convergence and how these neuro-immune interactions alter the progression of axonal injury following TBI.
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Affiliation(s)
- Karen M Gorse
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA, United States
| | - Audrey D Lafrenaye
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA, United States
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9
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Hui CW, St-Pierre A, El Hajj H, Remy Y, Hébert SS, Luheshi GN, Srivastava LK, Tremblay MÈ. Prenatal Immune Challenge in Mice Leads to Partly Sex-Dependent Behavioral, Microglial, and Molecular Abnormalities Associated with Schizophrenia. Front Mol Neurosci 2018; 11:13. [PMID: 29472840 PMCID: PMC5809492 DOI: 10.3389/fnmol.2018.00013] [Citation(s) in RCA: 107] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 01/09/2018] [Indexed: 01/25/2023] Open
Abstract
Epidemiological studies revealed that environmental factors comprising prenatal infection are strongly linked to risk for later development of neuropsychiatric disorders such as schizophrenia. Considering strong sex differences in schizophrenia and its increased prevalence in males, we designed a methodological approach to investigate possible sex differences in pathophysiological mechanisms. Prenatal immune challenge was modeled by systemic administration of the viral mimic polyinosinic-polycytidylic acid (Poly I:C) to C57BL/6 mice at embryonic day 9.5. The consequences on behavior, gene expression, and microglia—brain immune cells that are critical for normal development—were characterized in male vs. female offspring at adulthood. The cerebral cortex, hippocampus, and cerebellum, regions where structural and functional alterations were mainly described in schizophrenia patients, were selected for cellular and molecular analyses. Confocal and electron microscopy revealed most pronounced differences in microglial distribution, arborization, cellular stress, and synaptic interactions in the hippocampus of male vs. female offspring exposed to Poly I:C. Sex differences in microglia were also measured under both steady-state and Poly I:C conditions. These microglial alterations were accompanied by behavioral impairment, affecting for instance sensorimotor gating, in males. Consistent with these results, increased expression of genes related to inflammation was measured in cerebral cortex and hippocampus of males challenged with Poly I:C. Overall, these findings suggest that schizophrenia's higher incidence in males might be associated, among other mechanisms, with an increased microglial reactivity to prenatal immune challenges, hence determining disease outcomes into adulthood.
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Affiliation(s)
- Chin W Hui
- Axe Neurosciences, CRCHU de Québec-Université Laval, Québec, QC, Canada
| | - Abygaël St-Pierre
- Axe Neurosciences, CRCHU de Québec-Université Laval, Québec, QC, Canada
| | - Hassan El Hajj
- Axe Neurosciences, CRCHU de Québec-Université Laval, Québec, QC, Canada
| | - Yvan Remy
- Axe Neurosciences, CRCHU de Québec-Université Laval, Québec, QC, Canada
| | - Sébastien S Hébert
- Axe Neurosciences, CRCHU de Québec-Université Laval, Québec, QC, Canada.,Département de Psychiatrie et Neurosciences, Université Laval, Québec, QC, Canada
| | - Giamal N Luheshi
- Department of Psychiatry, Douglas Mental Health University Institute, McGill University, Montréal, QC, Canada
| | - Lalit K Srivastava
- Department of Psychiatry, Douglas Mental Health University Institute, McGill University, Montréal, QC, Canada
| | - Marie-Ève Tremblay
- Axe Neurosciences, CRCHU de Québec-Université Laval, Québec, QC, Canada.,Département de Médecine Moléculaire, Université Laval, Québec, QC, Canada
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10
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Yang H, Cheng X, Yang YL, Wang YH, Du GH. Ramulus Cinnamomi extract attenuates neuroinflammatory responses via downregulating TLR4/MyD88 signaling pathway in BV2 cells. Neural Regen Res 2017; 12:1860-1864. [PMID: 29239332 PMCID: PMC5745840 DOI: 10.4103/1673-5374.219048] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Ramulus Cinnamomi (RC), a traditional Chinese herb, has been used to attenuate inflammatory responses. The purpose of this study was to investigate the effect of RC extract on lipopolysaccharide (LPS)-induced neuroinflammation in BV2 microglial cells and the underlying mechanisms involved. BV2 cells were incubated with normal medium (control group), LPS, LPS plus 30 μg/mL RC extract, or LPS plus 100 μg/mL RC extract. The BV2 cell morphology was observed under an optical microscope and cell viability was detected by MTT assay. Nitric oxide level in BV2 cells was detected using Griess regents, and the levels of interleukin-6, interleukin-1β, and tumor necrosis factor α in BV2 cells were determined by ELISA. The expression levels of cyclooxygenase-2, Toll-like receptor 4 and myeloid differentiation factor 88 proteins were detected by western blot assay. Compared with the LPS group, both 30 and 100 μg/mL RC extract had no significant effect on the viability of BV2 cells. The levels of nitric oxide, interleukin-6, interleukin-1β and tumor necrosis factor α in BV2 cells were all significantly increased after LPS induction, and the levels were significantly reversed after treatment with 30 and 100 μg/mL RC extract. Furthermore, RC extract significantly inhibited the protein expression levels of cyclooxygenase-2, Toll-like receptor 4 and myeloid differentiation factor 88 in LPS-induced BV2 cells. Our findings suggest that RC extract alleviates neuroinflammation by downregulating the TLR4/MyD88 signaling pathway.
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Affiliation(s)
- Huan Yang
- Beijing Key Laboratory of Drug Target Identification and Drug Screening, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Xiao Cheng
- Beijing Key Laboratory of Drug Target Identification and Drug Screening, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Ying-Lin Yang
- Beijing Key Laboratory of Drug Target Identification and Drug Screening, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Yue-Hua Wang
- Beijing Key Laboratory of Drug Target Identification and Drug Screening, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing; State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Guan-Hua Du
- Beijing Key Laboratory of Drug Target Identification and Drug Screening, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing; State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
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