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Guo Y, Xu S, Pan X, Xin W, Cao W, Ma W, Li L, Shen Q, Li Z. Psoralen protects neurons and alleviates neuroinflammation by regulating microglial M1/M2 polarization via inhibition of the Fyn-PKCδ pathway. Int Immunopharmacol 2024; 137:112493. [PMID: 38897126 DOI: 10.1016/j.intimp.2024.112493] [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: 04/03/2024] [Revised: 05/26/2024] [Accepted: 06/12/2024] [Indexed: 06/21/2024]
Abstract
Microglia-mediated neuroinflammation is closely associated with many neurodegenerative diseases. Psoralen has potential for the treatment of many diseases, however, the anti-neuroinflammatory and neuroprotective effects of psoralen have been unclear. This study investigated the anti-neuroinflammatory and neuroprotective effects of psoralen and its regulation of microglial M1/M2 polarization. The LPS-induced mice model was used to test anti-neuroinflammatory effects, regulatory effects on microglia polarization, and neuroprotective effects of psoralen in vivo. The LPS-induced BV2 model was used to test the anti-neuroinflammatory effects and the regulatory effects and mechanisms on microglial M1/M2 polarization of psoralen in vitro. PC12 cell model induced by conditioned medium of BV2 cells was used to validate the protective effects of psoralen against neuroinflammation-induced neuronal damage. These results showed that psoralen inhibited the expression of iNOS, CD86, and TNF-α, and increased the expression of Arg-1, CD206, and IL-10. These results indicated that psoralen inhibited the M1 microglial phenotype and promoted the M2 microglial phenotype. Further studies showed that psoralen inhibited the phosphorylation of Fyn and PKCδ, thereby inhibiting activation of the MAPKs and NF-κB pathways and suppressing the expression of pro-inflammatory cytokines in microglia. Furthermore, psoralen reduced oxidative stress, neuronal damage, and apoptosis via inhibition of neuroinflammation. For the first time, this study showed that psoralen protected neurons and alleviated neuroinflammation by regulating microglial M1/M2 polarization, which may be mediated by inhibition of the Fyn-PKCδ pathway. Thus, psoralen may be a potential agent in the treatment of neuroinflammation-related diseases.
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Affiliation(s)
- Yaping Guo
- School of Pharmacy, Binzhou Medical University, Yantai, Shandong, China
| | - Sai Xu
- School of Pharmacy, Binzhou Medical University, Yantai, Shandong, China
| | - Xiaohong Pan
- School of Pharmacy, Binzhou Medical University, Yantai, Shandong, China
| | - Wenyu Xin
- School of Pharmacy, Binzhou Medical University, Yantai, Shandong, China
| | - Wenli Cao
- School of Pharmacy, Binzhou Medical University, Yantai, Shandong, China
| | - Wenya Ma
- School of Pharmacy, Binzhou Medical University, Yantai, Shandong, China
| | - Li Li
- Department of Pharmacy, Zhejiang Hospital, Hangzhou 310013, Zhejiang, China
| | - Qi Shen
- Department of Pharmacy, Zhejiang Hospital, Hangzhou 310013, Zhejiang, China.
| | - Zhipeng Li
- School of Pharmacy, Binzhou Medical University, Yantai, Shandong, China.
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Lei Z, Ritzel RM, Li Y, Li H, Faden AI, Wu J. Old age alters inflammation and autophagy signaling in the brain, leading to exacerbated neurological outcomes after spinal cord injury in male mice. Brain Behav Immun 2024; 120:439-451. [PMID: 38925420 PMCID: PMC11269014 DOI: 10.1016/j.bbi.2024.06.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2024] [Revised: 05/20/2024] [Accepted: 06/23/2024] [Indexed: 06/28/2024] Open
Abstract
Older patients with spinal cord injury (SCI) have different features with regard to neurological characteristics after injury. Recent large-scale longitudinal population-based studies showed that individuals with SCI are at a higher risk of developing dementia than non-SCI patients, indicating that SCI is a potential risk factor for dementia. Aging is known to potentiate inflammation and neurodegeneration at the injured site leading to impaired recovery from SCI. However, no research has been aimed at studying the mechanisms of SCI-mediated cognitive impairment in the elderly. The present study examined neurobehavioral and molecular changes in the brain and the underlying mechanisms associated with brain dysfunction in aged C57BL/6 male mice using a contusion SCI model. At 2 months post-injury, aged mice displayed worse performance in locomotor, cognitive and depressive-like behavioral tests compared to young adult animals. Histopathology in injured spinal cord tissue was exacerbated in aged SCI mice. In the brain, transcriptomic analysis with NanoString neuropathology panel identified activated microglia and dysregulated autophagy as the most significantly altered pathways by both age and injury. These findings were further validated by flow cytometry, which demonstrated increased myeloid and lymphocytes infiltration at both the injured site and brain of aged mice. Moreover, SCI in aged mice altered microglial function and dysregulated autophagy in microglia, resulting in worsened neurodegeneration. Taken together, our data indicate that old age exacerbates neuropathological changes in both the injured spinal cord and remote brain regions leading to poorer functional outcomes, at least in part, through altered inflammation and autophagy function.
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Affiliation(s)
- Zhuofan Lei
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Rodney M Ritzel
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Yun Li
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Hui Li
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Alan I Faden
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Junfang Wu
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD, 21201, USA.
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3
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Chen Q, Wu B, Shi Z, Wang Y, Yuan Y, Chen X, Wang Y, Hu J, Mao L, Gao Y, Wu G. LncRNA H19 knockdown promotes neuropathologic and functional recovery via the Nrf2/HO-1 axis after traumatic brain injury. CNS Neurosci Ther 2024; 30:e14870. [PMID: 39049714 PMCID: PMC11269889 DOI: 10.1111/cns.14870] [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: 05/12/2024] [Revised: 07/07/2024] [Accepted: 07/08/2024] [Indexed: 07/27/2024] Open
Abstract
AIMS Traumatic brain injury (TBI) stands as a significant concern in public health, frequently leading to enduring neurological deficits. Long non-coding RNA H19 (lncRNA H19) exerts a potential regulator role in the pathology of brain injury. This study investigates the effects of lncRNA H19 knockdown (H19-KD) on the pathophysiology of TBI and its potential neuroprotective mechanisms. METHODS Controlled cortical impact was employed to establish a stable TBI mouse model. The expression levels of various genes in perilesional cortex and striatum tissue after TBI was detected by RT-qPCR. AAV9-shRNA-H19 was injected into the lateral ventricle of mice to knockdown the expression of lncRNA H19. Various behavioral tests were performed to evaluate sensorimotor and cognitive functions after TBI. Immunofluorescence and Nissl staining were performed to assess brain tissue damage and neuroinflammation. The Nrf2 and HO-1 expression was performed by Western blot. RESULTS After TBI, the expression of lncRNA H19 was elevated in perilesional tissue and gradually reverted to baseline. Behavioral tests demonstrated that H19-KD significantly promoted the recovery of sensorimotor and cognitive functions after TBI. Besides, H19-KD reduced brain tissue loss, preserved neuronal integrity, and ameliorated white matter damage at the histological level. In addition, H19-KD restrained the pro-inflammatory and facilitated anti-inflammatory phenotypes of microglia/macrophages, attenuating the neuroinflammatory response after TBI. Furthermore, H19-KD promoted activation of the Nrf2/HO-1 axis after TBI, while suppression of Nrf2 partially abolished the neuroprotective effect. CONCLUSION H19-KD exerts neuroprotective effects after TBI in mice, partially mediated by the activation of the Nrf2/HO-1 axis.
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Affiliation(s)
- Qiankang Chen
- Department of Neurosurgery of Huashan Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceInstitutes of Brain Science, Fudan UniversityShanghaiChina
| | - Biwu Wu
- Department of Neurosurgery of Huashan Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceInstitutes of Brain Science, Fudan UniversityShanghaiChina
| | - Ziyu Shi
- Department of Neurosurgery of Huashan Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceInstitutes of Brain Science, Fudan UniversityShanghaiChina
| | - Yana Wang
- Department of Neurosurgery of Huashan Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceInstitutes of Brain Science, Fudan UniversityShanghaiChina
| | - Yiwen Yuan
- Department of Neurosurgery of Huashan Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceInstitutes of Brain Science, Fudan UniversityShanghaiChina
| | - Xingdong Chen
- Department of Neurosurgery of Huashan Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceInstitutes of Brain Science, Fudan UniversityShanghaiChina
| | - Yuqing Wang
- Department of Neurosurgery of Huashan Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceInstitutes of Brain Science, Fudan UniversityShanghaiChina
| | - Jin Hu
- Department of Neurosurgery of Huashan Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceInstitutes of Brain Science, Fudan UniversityShanghaiChina
| | - Leilei Mao
- Department of Neurosurgery of Huashan Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceInstitutes of Brain Science, Fudan UniversityShanghaiChina
| | - Yanqin Gao
- Department of Neurosurgery of Huashan Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceInstitutes of Brain Science, Fudan UniversityShanghaiChina
| | - Gang Wu
- Department of Neurosurgery of Huashan Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceInstitutes of Brain Science, Fudan UniversityShanghaiChina
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4
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Cox JEJ, Pham KD, Keck AW, Wright Z, Thomas MA, Freeman WM, Ocañas SR. Flow Cytometry Analysis of Microglial Phenotypes in the Murine Brain During Aging and Disease. Bio Protoc 2024; 14:e5018. [PMID: 38948260 PMCID: PMC11211077 DOI: 10.21769/bioprotoc.5018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 05/19/2024] [Accepted: 05/28/2024] [Indexed: 07/02/2024] Open
Abstract
Microglia, the brain's primary resident immune cell, exists in various phenotypic states depending on intrinsic and extrinsic signaling. Distinguishing between these phenotypes can offer valuable biological insights into neurodevelopmental and neurodegenerative processes. Recent advances in single-cell transcriptomic profiling have allowed for increased granularity and better separation of distinct microglial states. While techniques such as immunofluorescence and single-cell RNA sequencing (scRNA-seq) are available to differentiate microglial phenotypes and functions, these methods present notable limitations, including challenging quantification methods, high cost, and advanced analytical techniques. This protocol addresses these limitations by presenting an optimized cell preparation procedure that prevents ex vivo activation and a flow cytometry panel to distinguish four distinct microglial states from murine brain tissue. Following cell preparation, fluorescent antibodies were applied to label 1) homeostatic, 2) disease-associated (DAM), 3) interferon response (IRM), and 4) lipid-droplet accumulating (LDAM) microglia, based on gene markers identified in previous scRNA-Seq studies. Stained cells were analyzed by flow cytometry to assess phenotypic distribution as a function of age and sex. A key advantage of this procedure is its adaptability, allowing the panel provided to be enhanced using additional markers with an appropriate cell analyzer (i.e., Cytek Aurora 5 laser spectral flow cytometer) and interrogating different brain regions or disease models. Additionally, this protocol does not require microglial cell sorting, resulting in a relatively quick and straightforward experiment. Ultimately, this protocol can compare the distribution of microglial phenotypic states between various experimental groups, such as disease state or age, with a lower cost and higher throughput than scRNA-seq. Key features • Analysis of microglial phenotypes from murine brain without the need for cell sorting, imaging, or scRNA-seq. • This protocol can distinguish between homeostatic, disease-associated (DAM), lipid-droplet accumulating (LDAM), and interferon response (IRM) microglia from any murine brain region and/or disease model of interest. • This protocol can be modified to incorporate additional markers of interest or dyes when using a cell analyzer capable of multiple color detections.
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Affiliation(s)
- Jillian E. J. Cox
- Neuroscience Program, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Genes and Human Disease, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Kevin D. Pham
- Genes and Human Disease, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Alex W. Keck
- Genes and Human Disease, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Zsabre Wright
- Genes and Human Disease, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Manu A. Thomas
- Genes and Human Disease, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Willard M. Freeman
- Neuroscience Program, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Genes and Human Disease, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Sarah R. Ocañas
- Neuroscience Program, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Genes and Human Disease, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
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5
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Pybus AF, Bitarafan S, Brothers RO, Rohrer A, Khaitan A, Moctezuma FR, Udeshi K, Davies B, Triplett S, Griffin MN, Dammer EB, Rangaraju S, Buckley EM, Wood LB. Profiling the neuroimmune cascade in 3xTg-AD mice exposed to successive mild traumatic brain injuries. J Neuroinflammation 2024; 21:156. [PMID: 38872143 PMCID: PMC11177462 DOI: 10.1186/s12974-024-03128-1] [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: 02/16/2024] [Accepted: 05/12/2024] [Indexed: 06/15/2024] Open
Abstract
Repetitive mild traumatic brain injuries (rmTBI) sustained within a window of vulnerability can result in long term cognitive deficits, depression, and eventual neurodegeneration associated with tau pathology, amyloid beta (Aβ) plaques, gliosis, and neuronal and functional loss. However, a comprehensive study relating acute changes in immune signaling and glial reactivity to neuronal changes and pathological markers after single and repetitive mTBIs is currently lacking. In the current study, we addressed the question of how repeated injuries affect the brain neuroimmune response in the acute phase of injury (< 24 h) by exposing the 3xTg-AD mouse model of tau and Aβ pathology to successive (1x-5x) once-daily weight drop closed-head injuries and quantifying immune markers, pathological markers, and transcriptional profiles at 30 min, 4 h, and 24 h after each injury. We used young adult 2-4 month old 3xTg-AD mice to model the effects of rmTBI in the absence of significant tau and Aβ pathology. We identified pronounced sexual dimorphism in this model, with females eliciting more diverse changes after injury compared to males. Specifically, females showed: (1) a single injury caused a decrease in neuron-enriched genes inversely correlated with inflammatory protein expression and an increase in AD-related genes within 24 h, (2) each injury significantly increased a group of cortical cytokines (IL-1α, IL-1β, IL-2, IL-9, IL-13, IL-17, KC) and MAPK phospho-proteins (phospho-Atf2, phospho-Mek1), several of which co-labeled with neurons and correlated with phospho-tau, and (3) repetitive injury caused increased expression of genes associated with astrocyte reactivity and macrophage-associated immune function. Collectively our data suggest that neurons respond to a single injury within 24 h, while other cell types, including astrocytes, transition to inflammatory phenotypes within days of repetitive injury.
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Affiliation(s)
- Alyssa F Pybus
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Sara Bitarafan
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Rowan O Brothers
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Alivia Rohrer
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Arushi Khaitan
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Felix Rivera Moctezuma
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Kareena Udeshi
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Brae Davies
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Sydney Triplett
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Martin N Griffin
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Eric B Dammer
- Center for Neurodegenerative Diseases, School of Medicine, Emory University, Atlanta, GA, USA
| | - Srikant Rangaraju
- Department of Neurology, School of Medicine, Yale University, New Haven, CT, USA
| | - Erin M Buckley
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA.
- Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA, USA.
- Children's Healthcare of Atlanta, Atlanta, GA, USA.
| | - Levi B Wood
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA.
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA.
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, USA.
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6
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Svačina MKR, Gao T, Sprenger-Svačina A, Lin J, Ganesh BP, Lee J, McCullough LD, Sheikh KA, Zhang G. Rejuvenating fecal microbiota transplant enhances peripheral nerve repair in aged mice by modulating endoneurial inflammation. Exp Neurol 2024; 376:114774. [PMID: 38599367 DOI: 10.1016/j.expneurol.2024.114774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 03/28/2024] [Accepted: 04/06/2024] [Indexed: 04/12/2024]
Abstract
Peripheral nerve injury (PNI) resulting from trauma or neuropathies can cause significant disability, and its prognosis deteriorates with age. Emerging evidence suggests that gut dysbiosis and reduced fecal short-chain fatty acids (SCFAs) contribute to an age-related systemic hyperinflammation (inflammaging), which hinders nerve recovery after injury. This study thus aimed to evaluate the pro-regenerative effects of a rejuvenating fecal microbiota transplant (FMT) in a preclinical PNI model using aged mice. Aged C57BL/6 mice underwent bilateral crush injuries to their sciatic nerves. Subsequently, they either received FMT from young donors at three and four days after the injury or retained their aged gut microbiota. We analyzed gut microbiome composition and SCFA concentrations in fecal samples. The integrity of the ileac mucosal barrier was assessed by immunofluorescence staining of Claudin-1. Flow cytometry was utilized to examine immune cells and cytokine production in the ileum, spleen, and sciatic nerve. Various assessments, including behavioural tests, electrophysiological studies, and morphometrical analyses, were conducted to evaluate peripheral nerve function and repair following injury. Rejuvenating FMT reversed age-related gut dysbiosis by increasing Actinobacteria, especially Bifidobacteriales genera. This intervention also led to an elevation of gut SCFA levels and mitigated age-related ileac mucosal leakiness in aged recipients. Additionally, it augmented the number of T-helper 2 (Th2) and regulatory T (Treg) cells in the ileum and spleen, with the majority being positive for anti-inflammatory interleukin-10 (IL-10). In sciatic nerves, rejuvenating FMT resulted in increased M2 macrophage counts and a higher IL-10 production by IL-10+TNF-α- M2 macrophage subsets. Ultimately, restoring a youthful gut microbiome in aged mice led to improved nerve repair and enhanced functional recovery after PNI. Considering that FMT is already a clinically available technique, exploring novel translational strategies targeting the gut microbiome to enhance nerve repair in the elderly seems promising and warrants further evaluation.
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Affiliation(s)
- Martin K R Svačina
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, 6431 Fannin Street, Houston, TX 77030, USA; Department of Neurology, Faculty of Medicine and University Hospital of Cologne, Kerpener Str. 62, 50937 Cologne, Germany
| | - Tong Gao
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, 6431 Fannin Street, Houston, TX 77030, USA
| | - Alina Sprenger-Svačina
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, 6431 Fannin Street, Houston, TX 77030, USA; Department of Neurology, Faculty of Medicine and University Hospital of Cologne, Kerpener Str. 62, 50937 Cologne, Germany
| | - Jianxin Lin
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, 6431 Fannin Street, Houston, TX 77030, USA
| | - Bhanu P Ganesh
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, 6431 Fannin Street, Houston, TX 77030, USA
| | - Juneyoung Lee
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, 6431 Fannin Street, Houston, TX 77030, USA
| | - Louise D McCullough
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, 6431 Fannin Street, Houston, TX 77030, USA
| | - Kazim A Sheikh
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, 6431 Fannin Street, Houston, TX 77030, USA
| | - Gang Zhang
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, 6431 Fannin Street, Houston, TX 77030, USA.
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7
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El Hamamy A, Iqbal Z, Mai Le N, Ranjan A, Zhang Y, Lin HW, Tan C, Patrizz A, McCullough LD, Li J. Targeted TGF-βR2 Knockdown in the Retrotrapezoid Nucleus Mitigates Respiratory Dysfunction and Cognitive Decline in a Mouse Model of Cerebral Amyloid Angiopathy with and without Stroke. RESEARCH SQUARE 2024:rs.3.rs-4438544. [PMID: 38854014 PMCID: PMC11160887 DOI: 10.21203/rs.3.rs-4438544/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Introduction Cerebral amyloid angiopathy (CAA) is characterized by the deposition of amyloid-beta peptides within cerebral blood vessels, leading to neurovascular complications. Ischemic strokes result from acute disruptions in cerebral blood flow, triggering metabolic disturbances and neurodegeneration. Both conditions often co-occur and are associated with respiratory dysfunctions. The retrotrapezoid nucleus (RTN), which is crucial for CO2 sensing and breathing regulation in the brainstem, may play a key role in breathing disorders seen in these conditions. This study aims to investigate the role of Transforming Growth Factor Beta (TGF-β) signaling in the RTN on respiratory and cognitive functions in CAA, both with and without concurrent ischemic stroke. Methods Adult male Tg-SwDI (CAA model) mice and C57BL/6 wild-type controls underwent stereotaxic injections of lentivirus targeting TGF-β2R2 in the RTN. Stroke was induced by middle cerebral artery occlusion using a monofilament. Respiratory functions were assessed using whole-body plethysmography, while cognitive functions were evaluated through the Barnes Maze and Novel Object Recognition Test (NORT). Immunohistochemical analysis was conducted to measure TGF-βR2 and GFAP expressions in the RTN. Results CAA mice exhibited significant respiratory dysfunctions, including reduced respiratory rates and increased apnea frequency, as well as impaired cognitive performance. TGF-βR2 knockdown in the RTN improved respiratory functions and cognitive outcomes in CAA mice. In CAA mice with concurrent stroke, TGF-βR2 knockdown similarly enhanced respiratory and cognitive functions. Immunohistochemistry confirmed reduced TGF-βR2 and GFAP expressions in the RTN following knockdown. Conclusions Our findings demonstrate that increased TGF-β signaling and gliosis in the RTN contribute to respiratory and cognitive dysfunctions in CAA and CAA with stroke. Targeting TGF-βR2 signaling in the RTN offers a promising therapeutic strategy to mitigate these impairments. This study is the first to report a causal link between brainstem gliosis and both respiratory and cognitive dysfunctions in CAA and stroke models.
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Affiliation(s)
| | - Zahid Iqbal
- University of Texas Health Science Center at Houston
| | - Ngoc Mai Le
- University of Texas Health Science Center at Houston
| | - Arya Ranjan
- University of Texas Health Science Center at Houston
| | - YuXing Zhang
- University of Texas Health Science Center at Houston
| | - Hung Wen Lin
- University of Texas Health Science Center at Houston
| | - Chunfeng Tan
- University of Texas Health Science Center at Houston
| | | | | | - Jun Li
- University of Texas Health Science Center at Houston
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8
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Gathings A, Zaman V, Banik NL, Haque A. Insights into Calpain Activation and Rho-ROCK Signaling in Parkinson's Disease and Aging. Biomedicines 2024; 12:1074. [PMID: 38791036 PMCID: PMC11117523 DOI: 10.3390/biomedicines12051074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Revised: 04/26/2024] [Accepted: 05/02/2024] [Indexed: 05/26/2024] Open
Abstract
Parkinson's disease (PD), a progressive neurodegenerative disease, has no cure, and current therapies are not effective at halting disease progression. The disease affects mid-brain dopaminergic neurons and, subsequently, the spinal cord, contributing to many debilitating symptoms associated with PD. The GTP-binding protein, Rho, plays a significant role in the cellular pathology of PD. The downstream effector of Rho, Rho-associated kinase (ROCK), plays multiple functions, including microglial activation and induction of inflammatory responses. Activated microglia have been implicated in the pathology of many neurodegenerative diseases, including PD, that initiate inflammatory responses, leading to neuron death. Calpain expression and activity is increased following glial activation, which triggers the Rho-ROCK pathway and induces inflammatory T cell activation and migration as well as mediates toxic α-synuclein (α-syn) aggregation and neuron death, indicating a pivotal role for calpain in the inflammatory and degenerative processes in PD. Increased calpain activity and Rho-ROCK activation may represent a new mechanism for increased oxidative damage in aging. This review will summarize calpain activation and the role of the Rho-ROCK pathway in oxidative stress and α-syn aggregation, their influence on the neurodegenerative process in PD and aging, and possible strategies and research directions for therapeutic intervention.
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Affiliation(s)
- Amy Gathings
- Department of Microbiology and Immunology, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425, USA; (A.G.); (N.L.B.)
- Department of Neurosurgery, Medical University of South Carolina, 96 Jonathan Lucas Street, Charleston, SC 29425, USA;
| | - Vandana Zaman
- Department of Neurosurgery, Medical University of South Carolina, 96 Jonathan Lucas Street, Charleston, SC 29425, USA;
- Ralph H. Johnson Veterans Administration Medical Center, 109 Bee Street, Charleston, SC 29401, USA
| | - Narendra L. Banik
- Department of Microbiology and Immunology, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425, USA; (A.G.); (N.L.B.)
- Department of Neurosurgery, Medical University of South Carolina, 96 Jonathan Lucas Street, Charleston, SC 29425, USA;
- Ralph H. Johnson Veterans Administration Medical Center, 109 Bee Street, Charleston, SC 29401, USA
| | - Azizul Haque
- Department of Microbiology and Immunology, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425, USA; (A.G.); (N.L.B.)
- Department of Neurosurgery, Medical University of South Carolina, 96 Jonathan Lucas Street, Charleston, SC 29425, USA;
- Ralph H. Johnson Veterans Administration Medical Center, 109 Bee Street, Charleston, SC 29401, USA
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9
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El Baassiri MG, Raouf Z, Badin S, Escobosa A, Sodhi CP, Nasr IW. Dysregulated brain-gut axis in the setting of traumatic brain injury: review of mechanisms and anti-inflammatory pharmacotherapies. J Neuroinflammation 2024; 21:124. [PMID: 38730498 PMCID: PMC11083845 DOI: 10.1186/s12974-024-03118-3] [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: 02/29/2024] [Accepted: 04/30/2024] [Indexed: 05/13/2024] Open
Abstract
Traumatic brain injury (TBI) is a chronic and debilitating disease, associated with a high risk of psychiatric and neurodegenerative diseases. Despite significant advancements in improving outcomes, the lack of effective treatments underscore the urgent need for innovative therapeutic strategies. The brain-gut axis has emerged as a crucial bidirectional pathway connecting the brain and the gastrointestinal (GI) system through an intricate network of neuronal, hormonal, and immunological pathways. Four main pathways are primarily implicated in this crosstalk, including the systemic immune system, autonomic and enteric nervous systems, neuroendocrine system, and microbiome. TBI induces profound changes in the gut, initiating an unrestrained vicious cycle that exacerbates brain injury through the brain-gut axis. Alterations in the gut include mucosal damage associated with the malabsorption of nutrients/electrolytes, disintegration of the intestinal barrier, increased infiltration of systemic immune cells, dysmotility, dysbiosis, enteroendocrine cell (EEC) dysfunction and disruption in the enteric nervous system (ENS) and autonomic nervous system (ANS). Collectively, these changes further contribute to brain neuroinflammation and neurodegeneration via the gut-brain axis. In this review article, we elucidate the roles of various anti-inflammatory pharmacotherapies capable of attenuating the dysregulated inflammatory response along the brain-gut axis in TBI. These agents include hormones such as serotonin, ghrelin, and progesterone, ANS regulators such as beta-blockers, lipid-lowering drugs like statins, and intestinal flora modulators such as probiotics and antibiotics. They attenuate neuroinflammation by targeting distinct inflammatory pathways in both the brain and the gut post-TBI. These therapeutic agents exhibit promising potential in mitigating inflammation along the brain-gut axis and enhancing neurocognitive outcomes for TBI patients.
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Affiliation(s)
- Mahmoud G El Baassiri
- Pediatric Surgery, Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA
| | - Zachariah Raouf
- Pediatric Surgery, Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA
| | - Sarah Badin
- Pediatric Surgery, Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA
| | - Alejandro Escobosa
- Pediatric Surgery, Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA
| | - Chhinder P Sodhi
- Pediatric Surgery, Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA
| | - Isam W Nasr
- Pediatric Surgery, Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA.
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10
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Ritzel RM, Li Y, Jiao Y, Doran SJ, Khan N, Henry RJ, Brunner K, Loane DJ, Faden AI, Szeto GL, Wu J. Bi-directional neuro-immune dysfunction after chronic experimental brain injury. J Neuroinflammation 2024; 21:83. [PMID: 38581043 PMCID: PMC10996305 DOI: 10.1186/s12974-024-03082-y] [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: 01/15/2024] [Accepted: 03/30/2024] [Indexed: 04/07/2024] Open
Abstract
BACKGROUND It is well established that traumatic brain injury (TBI) causes acute and chronic alterations in systemic immune function and that systemic immune changes contribute to posttraumatic neuroinflammation and neurodegeneration. However, how TBI affects bone marrow (BM) hematopoietic stem/progenitor cells chronically and to what extent such changes may negatively impact innate immunity and neurological function has not been examined. METHODS To further understand the role of BM cell derivatives on TBI outcome, we generated BM chimeric mice by transplanting BM from chronically injured or sham (i.e., 90 days post-surgery) congenic donor mice into otherwise healthy, age-matched, irradiated CD45.2 C57BL/6 (WT) hosts. Immune changes were evaluated by flow cytometry, multiplex ELISA, and NanoString technology. Moderate-to-severe TBI was induced by controlled cortical impact injury and neurological function was measured using a battery of behavioral tests. RESULTS TBI induced chronic alterations in the transcriptome of BM lineage-c-Kit+Sca1+ (LSK+) cells in C57BL/6 mice, including modified epigenetic and senescence pathways. After 8 weeks of reconstitution, peripheral myeloid cells from TBI→WT mice showed significantly higher oxidative stress levels and reduced phagocytic activity. At eight months after reconstitution, TBI→WT chimeric mice were leukopenic, with continued alterations in phagocytosis and oxidative stress responses, as well as persistent neurological deficits. Gene expression analysis revealed BM-driven changes in neuroinflammation and neuropathology after 8 weeks and 8 months of reconstitution, respectively. Chimeric mice subjected to TBI at 8 weeks and 8 months post-reconstitution showed that longer reconstitution periods (i.e., time post-injury) were associated with increased microgliosis and leukocyte infiltration. Pre-treatment with a senolytic agent, ABT-263, significantly improved behavioral performance of aged C57BL/6 mice at baseline, although it did not attenuate neuroinflammation in the acutely injured brain. CONCLUSIONS TBI causes chronic activation and progressive dysfunction of the BM stem/progenitor cell pool, which drives long-term deficits in hematopoiesis, innate immunity, and neurological function, as well as altered sensitivity to subsequent brain injury.
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Affiliation(s)
- Rodney M Ritzel
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA.
| | - Yun Li
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Yun Jiao
- Department of Chemical, Biochemical and Environmental Engineering, University of Maryland, Baltimore County, Baltimore, MD, 21250, USA
| | - Sarah J Doran
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Niaz Khan
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Rebecca J Henry
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Kavitha Brunner
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - David J Loane
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Alan I Faden
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Gregory L Szeto
- Department of Chemical, Biochemical and Environmental Engineering, University of Maryland, Baltimore County, Baltimore, MD, 21250, USA
| | - Junfang Wu
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.
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11
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Li Y, Ritzel RM, He J, Liu S, Zhang L, Wu J. Ablation of the integrin CD11b mac-1 limits deleterious responses to traumatic spinal cord injury and improves functional recovery in mice. RESEARCH SQUARE 2024:rs.3.rs-4196316. [PMID: 38645238 PMCID: PMC11030505 DOI: 10.21203/rs.3.rs-4196316/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: 04/23/2024]
Abstract
Background Spinal cord injury (SCI) causes long-term sensorimotor deficits and posttraumatic neuropathic pain, with no effective treatment. In part, this reflects an incomplete understanding of the complex secondary pathobiological mechanisms involved. SCI triggers microglial/macrophage activation with distinct pro-inflammatory or inflammation-resolving phenotypes, which potentiate tissue damage or facilitate functional repair, respectively. The major integrin Mac-1 (CD11b/CD18, αMβ2 or CR3), a heterodimer consisting of αM (CD11b) and β2 (CD18) chains, is generally regarded as a pro-inflammatory receptor in neurotrauma. Multiple immune cells of the myeloid lineage express CD11b, including microglia, macrophages, and neutrophils. In the present study, we examined the effects of CD11b gene ablation on posttraumatic neuroinflammation and functional outcomes after SCI. Methods Young adult age-matched female CD11b knockout (KO) mice and their wildtype (WT) littermates were subjected to moderate thoracic spinal cord contusion. Neuroinflammation in the injured spinal cord was assessed with qPCR, flow cytometry, NanoString, and RNAseq. Neurological function was evaluated with the Basso Mouse Scale (BMS), gait analysis, thermal hyperesthesia, and mechanical allodynia. Lesion volume was evaluated by GFAP-DAB immunohistochemistry, followed by analysis with unbiased stereology. Results qPCR analysis showed a rapid and persistent upregulation of CD11b mRNA starting from 1d after injury, which persisted up to 28 days. At 1d post-injury, increased expression levels of genes that regulate inflammation-resolving processes were observed in CD11b KO mice. Flow cytometry analysis of CD45intLy6C-CX3CR1+ microglia, CD45hiLy6C+Ly6G- monocytes, and CD45hiLy6C+Ly6G+ neutrophils revealed significantly reduced cell counts as well as reactive oxygen production in CD11b KO mice at d3 post-injury. Further examination of the injured spinal cord with NanoString Mouse Neuroinflammation Panel and RNAseq showed upregulated expression of pro-inflammatory genes, but downregulated expression of the reactive oxygen species pathway. Importantly, CD11b KO mice exhibited significantly improved locomotor function, reduced cutaneous mechanical/thermal hypersensitivity, and limited tissue damage at 8 weeks post-injury. Conclusion Collectively, our data suggest an important role for CD11b in regulating tissue inflammation and functional outcome following SCI. Thus, the integrin CD11b represents a potential target that may lead to novel therapeutic strategies for SCI.
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Affiliation(s)
- Yun Li
- University of Maryland School of Medicine
| | | | - Junyun He
- University of Maryland School of Medicine
| | - Simon Liu
- University of Maryland School of Medicine
| | - Li Zhang
- University of Maryland School of Medicine
| | - Junfang Wu
- University of Maryland School of Medicine
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12
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Katchur NJ, Notterman DA. Recent insights from non-mammalian models of brain injuries: an emerging literature. Front Neurol 2024; 15:1378620. [PMID: 38566857 PMCID: PMC10985199 DOI: 10.3389/fneur.2024.1378620] [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: 01/29/2024] [Accepted: 02/26/2024] [Indexed: 04/04/2024] Open
Abstract
Traumatic brain injury (TBI) is a major global health concern and is increasingly recognized as a risk factor for neurodegenerative diseases including Alzheimer's disease (AD) and chronic traumatic encephalopathy (CTE). Repetitive TBIs (rTBIs), commonly observed in contact sports, military service, and intimate partner violence (IPV), pose a significant risk for long-term sequelae. To study the long-term consequences of TBI and rTBI, researchers have typically used mammalian models to recapitulate brain injury and neurodegenerative phenotypes. However, there are several limitations to these models, including: (1) lengthy observation periods, (2) high cost, (3) difficult genetic manipulations, and (4) ethical concerns regarding prolonged and repeated injury of a large number of mammals. Aquatic vertebrate model organisms, including Petromyzon marinus (sea lampreys), zebrafish (Danio rerio), and invertebrates, Caenorhabditis elegans (C. elegans), and Drosophila melanogaster (Drosophila), are emerging as valuable tools for investigating the mechanisms of rTBI and tauopathy. These non-mammalian models offer unique advantages, including genetic tractability, simpler nervous systems, cost-effectiveness, and quick discovery-based approaches and high-throughput screens for therapeutics, which facilitate the study of rTBI-induced neurodegeneration and tau-related pathology. Here, we explore the use of non-vertebrate and aquatic vertebrate models to study TBI and neurodegeneration. Drosophila, in particular, provides an opportunity to explore the longitudinal effects of mild rTBI and its impact on endogenous tau, thereby offering valuable insights into the complex interplay between rTBI, tauopathy, and neurodegeneration. These models provide a platform for mechanistic studies and therapeutic interventions, ultimately advancing our understanding of the long-term consequences associated with rTBI and potential avenues for intervention.
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Affiliation(s)
- Nicole J. Katchur
- Department of Molecular Biology, Princeton University, Princeton, NJ, United States
- Rutgers-Robert Wood Johnson Medical School, Piscataway, NJ, United States
| | - Daniel A. Notterman
- Department of Molecular Biology, Princeton University, Princeton, NJ, United States
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13
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Boland R, Kokiko-Cochran ON. Deplete and repeat: microglial CSF1R inhibition and traumatic brain injury. Front Cell Neurosci 2024; 18:1352790. [PMID: 38450286 PMCID: PMC10915023 DOI: 10.3389/fncel.2024.1352790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 01/25/2024] [Indexed: 03/08/2024] Open
Abstract
Traumatic brain injury (TBI) is a public health burden affecting millions of people. Sustained neuroinflammation after TBI is often associated with poor outcome. As a result, increased attention has been placed on the role of immune cells in post-injury recovery. Microglia are highly dynamic after TBI and play a key role in the post-injury neuroinflammatory response. Therefore, microglia represent a malleable post-injury target that could substantially influence long-term outcome after TBI. This review highlights the cell specific role of microglia in TBI pathophysiology. Microglia have been manipulated via genetic deletion, drug inhibition, and pharmacological depletion in various pre-clinical TBI models. Notably, colony stimulating factor 1 (CSF1) and its receptor (CSF1R) have gained much traction in recent years as a pharmacological target on microglia. CSF1R is a transmembrane tyrosine kinase receptor that is essential for microglia proliferation, differentiation, and survival. Small molecule inhibitors targeting CSF1R result in a swift and effective depletion of microglia in rodents. Moreover, discontinuation of the inhibitors is sufficient for microglia repopulation. Attention is placed on summarizing studies that incorporate CSF1R inhibition of microglia. Indeed, microglia depletion affects multiple aspects of TBI pathophysiology, including neuroinflammation, oxidative stress, and functional recovery with measurable influence on astrocytes, peripheral immune cells, and neurons. Taken together, the data highlight an important role for microglia in sustaining neuroinflammation and increasing risk of oxidative stress, which lends to neuronal damage and behavioral deficits chronically after TBI. Ultimately, the insights gained from CSF1R depletion of microglia are critical for understanding the temporospatial role that microglia develop in mediating TBI pathophysiology and recovery.
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Affiliation(s)
- Rebecca Boland
- Department of Neuroscience, College of Medicine, Chronic Brain Injury Program, Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, United States
| | - Olga N Kokiko-Cochran
- Department of Neuroscience, College of Medicine, Chronic Brain Injury Program, Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, United States
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14
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Bottom-Tanzer S, Corella S, Meyer J, Sommer M, Bolaños L, Murphy T, Quiñones S, Heiney S, Shtrahman M, Whalen M, Oren R, Higley MJ, Cardin JA, Noubary F, Armbruster M, Dulla C. Traumatic brain injury disrupts state-dependent functional cortical connectivity in a mouse model. Cereb Cortex 2024; 34:bhae038. [PMID: 38365273 DOI: 10.1093/cercor/bhae038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 01/17/2024] [Accepted: 01/18/2024] [Indexed: 02/18/2024] Open
Abstract
Traumatic brain injury (TBI) is the leading cause of death in young people and can cause cognitive and motor dysfunction and disruptions in functional connectivity between brain regions. In human TBI patients and rodent models of TBI, functional connectivity is decreased after injury. Recovery of connectivity after TBI is associated with improved cognition and memory, suggesting an important link between connectivity and functional outcome. We examined widespread alterations in functional connectivity following TBI using simultaneous widefield mesoscale GCaMP7c calcium imaging and electrocorticography (ECoG) in mice injured using the controlled cortical impact (CCI) model of TBI. Combining CCI with widefield cortical imaging provides us with unprecedented access to characterize network connectivity changes throughout the entire injured cortex over time. Our data demonstrate that CCI profoundly disrupts functional connectivity immediately after injury, followed by partial recovery over 3 weeks. Examining discrete periods of locomotion and stillness reveals that CCI alters functional connectivity and reduces theta power only during periods of behavioral stillness. Together, these findings demonstrate that TBI causes dynamic, behavioral state-dependent changes in functional connectivity and ECoG activity across the cortex.
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Affiliation(s)
- Samantha Bottom-Tanzer
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, United States
- MD/PhD Program, Tufts University School of Medicine, Boston, MA 02111, United States
- Neuroscience Program, Tufts Graduate School of Biomedical Sciences, Boston, MA 02111, United States
| | - Sofia Corella
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, United States
- MD/PhD Program, Case Western Reserve University School of Medicine, Cleveland, OH 44106, United States
| | - Jochen Meyer
- Department of Neurology, Baylor College of Medicine, Houston, TX 77030, United States
| | - Mary Sommer
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, United States
| | - Luis Bolaños
- Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
| | - Timothy Murphy
- Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
| | - Sadi Quiñones
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, United States
- Neuroscience Program, Tufts Graduate School of Biomedical Sciences, Boston, MA 02111, United States
| | - Shane Heiney
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA 52242, United States
| | - Matthew Shtrahman
- Department of Neurosciences, University of California San Diego, La Jolla, CA 92093, United States
| | - Michael Whalen
- Department of Pediatrics, Harvard Medical School, Massachusetts General Hospital, Boston, MA 02115, United States
| | - Rachel Oren
- Department of Neuroscience, Kavli Institute for Neuroscience, Yale School of Medicine, New Haven, CT 06510, United States
- Interdepartmental Neuroscience Program, Yale School of Medicine, New Haven, CT 06510, United States
| | - Michael J Higley
- Department of Neuroscience, Kavli Institute for Neuroscience, Yale School of Medicine, New Haven, CT 06510, United States
| | - Jessica A Cardin
- Department of Neuroscience, Kavli Institute for Neuroscience, Yale School of Medicine, New Haven, CT 06510, United States
| | - Farzad Noubary
- Department of Health Sciences, Northeastern University, Boston, MA 02115, United States
| | - Moritz Armbruster
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, United States
| | - Chris Dulla
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, United States
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15
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Obenaus A, Noarbe BP, Lee JB, Panchenko PE, Noarbe SD, Lee YC, Badaut J. Progressive lifespan modifications in the corpus callosum following a single juvenile concussion in male mice monitored by diffusion MRI. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.21.572925. [PMID: 38187748 PMCID: PMC10769374 DOI: 10.1101/2023.12.21.572925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Introduction The sensitivity of white matter (WM) in acute and chronic moderate-severe traumatic brain injury (TBI) has been established. In concussion syndromes, particularly in preclinical rodent models, there is lacking a comprehensive longitudinal study spanning the lifespan of the mouse. We previously reported early modifications to WM using clinically relevant neuroimaging and histological measures in a model of juvenile concussion at one month post injury (mpi) who then exhibited cognitive deficits at 12mpi. For the first time, we assess corpus callosum (CC) integrity across the lifespan after a single juvenile concussion utilizing diffusion MRI (dMRI). Methods C57Bl/6 mice were exposed to sham or two severities of closed-head concussion (Grade 1, G1, speed 2 m/sec, depth 1mm; Grade 2, G2, 3m/sec, 3mm) using an electromagnetic impactor at postnatal day 17. In vivo diffusion tensor imaging was conducted at 1, 3, 6, 12 and 18 mpi (21 directions, b=2000 mm2/sec) and processed for dMRI parametric maps: fractional anisotropy (FA), axial (AxD), radial (RD) and mean diffusivity (MD). Whole CC and regional CC data were extracted. To identify the biological basis of altered dMRI metrics, astrocyte and microglia in the CC were characterized at 1 and 12 mpi by immunohistochemistry. Results Whole CC analysis revealed altered FA and RD trajectories following juvenile concussion. Shams exhibited a temporally linear increase in FA with age while G1/G2 mice had plateaued FA values. G2 concussed mice exhibited high variance of dMRI metrics at 12mpi, which was attributed to the heterogeneity of TBI on the anterior CC. Regional analysis of dMRI metrics at the impact site unveiled significant differences between G2 and sham mice. The dMRI findings appear to be driven, in part, by loss of astrocyte process lengths and increased circularity and decreased cell span ratios in microglia. Conclusion For the first time, we demonstrate progressive perturbations to WM of male mice after a single juvenile concussion across the mouse lifespan. The CC alterations were dependent on concussion severity with elevated sensitivity in the anterior CC that was related to astrocyte and microglial morphology. Our findings suggest that long-term monitoring of children with juvenile concussive episodes using dMRI is warranted, focusing on vulnerable WM tracts.
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Affiliation(s)
- Andre Obenaus
- Department of Pediatrics, School of Medicine, University of California Irvine, Irvine, CA, USA
| | - Brenda P. Noarbe
- Department of Pediatrics, School of Medicine, University of California Irvine, Irvine, CA, USA
| | - Jeong Bin Lee
- Basic Science Department, Loma Linda University School of Medicine, Loma Linda, CA, US
| | | | - Sean D. Noarbe
- Department of Pediatrics, School of Medicine, University of California Irvine, Irvine, CA, USA
| | - Yu Chiao Lee
- Department of Pediatrics, School of Medicine, University of California Irvine, Irvine, CA, USA
| | - Jerome Badaut
- CNRS UMR 5536 RMSB-University of Bordeaux, Bordeaux, France
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16
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Abou-El-Hassan H, Bernstock JD, Chalif JI, Yahya T, Rezende RM, Weiner HL, Izzy S. Elucidating the neuroimmunology of traumatic brain injury: methodological approaches to unravel intercellular communication and function. Front Cell Neurosci 2023; 17:1322325. [PMID: 38162004 PMCID: PMC10756680 DOI: 10.3389/fncel.2023.1322325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 11/15/2023] [Indexed: 01/03/2024] Open
Abstract
The neuroimmunology of traumatic brain injury (TBI) has recently gained recognition as a crucial element in the secondary pathophysiological consequences that occur following neurotrauma. Both immune cells residing within the central nervous system (CNS) and those migrating from the periphery play significant roles in the development of secondary brain injury. However, the precise mechanisms governing communication between innate and adaptive immune cells remain incompletely understood, partly due to a limited utilization of relevant experimental models and techniques. Therefore, in this discussion, we outline current methodologies that can aid in the exploration of TBI neuroimmunology, with a particular emphasis on the interactions between resident neuroglial cells and recruited lymphocytes. These techniques encompass adoptive cell transfer, intra-CNS injection(s), selective cellular depletion, genetic manipulation, molecular neuroimaging, as well as in vitro co-culture systems and the utilization of organoid models. By incorporating key elements of both innate and adaptive immunity, these methods facilitate the examination of clinically relevant interactions. In addition to these preclinical approaches, we also detail an emerging avenue of research that seeks to leverage human biofluids. This approach enables the investigation of how resident and infiltrating immune cells modulate neuroglial responses after TBI. Considering the growing significance of neuroinflammation in TBI, the introduction and application of advanced methodologies will be pivotal in advancing translational research in this field.
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Affiliation(s)
- Hadi Abou-El-Hassan
- Ann Romney Center for Neurologic Diseases, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Joshua D. Bernstock
- Department of Neurosurgery, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Joshua I. Chalif
- Department of Neurosurgery, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Taha Yahya
- Ann Romney Center for Neurologic Diseases, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Rafael M. Rezende
- Ann Romney Center for Neurologic Diseases, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Howard L. Weiner
- Ann Romney Center for Neurologic Diseases, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Saef Izzy
- Ann Romney Center for Neurologic Diseases, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
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17
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Wangler LM, Godbout JP. Microglia moonlighting after traumatic brain injury: aging and interferons influence chronic microglia reactivity. Trends Neurosci 2023; 46:926-940. [PMID: 37723009 PMCID: PMC10592045 DOI: 10.1016/j.tins.2023.08.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 08/11/2023] [Accepted: 08/24/2023] [Indexed: 09/20/2023]
Abstract
Most of the individuals who experience traumatic brain injury (TBI) develop neuropsychiatric and cognitive complications that negatively affect recovery and health span. Activation of multiple inflammatory pathways persists after TBI, but it is unclear how inflammation contributes to long-term behavioral and cognitive deficits. One outcome of TBI is microglial priming and subsequent hyper-reactivity to secondary stressors, injuries, or immune challenges that further augment complications. Additionally, microglia priming with aging contributes to exaggerated glial responses to TBI. One prominent inflammatory pathway, interferon (IFN) signaling, is increased after TBI and may contribute to microglial priming and subsequent reactivity. This review discusses the contributions of microglia to inflammatory processes after TBI, as well as the influence of aging and IFNs on microglia reactivity and chronic inflammation after TBI.
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Affiliation(s)
- Lynde M Wangler
- Department of Neuroscience, The Ohio State University Wexner Medical Center, 333 W 10th Ave, Columbus, OH, USA
| | - Jonathan P Godbout
- Department of Neuroscience, The Ohio State University Wexner Medical Center, 333 W 10th Ave, Columbus, OH, USA; Institute for Behavioral Medicine Research, Ohio State University Wexner Medical Center, 460 Medical Center Drive, Columbus, OH, USA; Chronic Brain Injury Program, The Ohio State University, 190 North Oval Mall, Columbus, OH, USA.
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18
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Hasegawa Y, Kim J, Ursini G, Jouroukhin Y, Zhu X, Miyahara Y, Xiong F, Madireddy S, Obayashi M, Lutz B, Sawa A, Brown SP, Pletnikov MV, Kamiya A. Microglial cannabinoid receptor type 1 mediates social memory deficits in mice produced by adolescent THC exposure and 16p11.2 duplication. Nat Commun 2023; 14:6559. [PMID: 37880248 PMCID: PMC10600150 DOI: 10.1038/s41467-023-42276-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Accepted: 10/04/2023] [Indexed: 10/27/2023] Open
Abstract
Adolescent cannabis use increases the risk for cognitive impairments and psychiatric disorders. Cannabinoid receptor type 1 (Cnr1) is expressed not only in neurons and astrocytes, but also in microglia, which shape synaptic connections during adolescence. However, the role of microglia in mediating the adverse cognitive effects of delta-9-tetrahydrocannabinol (THC), the principal psychoactive constituent of cannabis, is not fully understood. Here, we report that in mice, adolescent THC exposure produces microglial apoptosis in the medial prefrontal cortex (mPFC), which was exacerbated in a model of 16p11.2 duplication, a representative copy number variation (CNV) risk factor for psychiatric disorders. These effects are mediated by microglial Cnr1, leading to reduction in the excitability of mPFC pyramidal-tract neurons and deficits in social memory in adulthood. Our findings suggest the microglial Cnr1 may contribute to adverse effect of cannabis exposure in genetically vulnerable individuals.
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Affiliation(s)
- Yuto Hasegawa
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Juhyun Kim
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Korea Brain Research Institute, Daegu, Republic of Korea
| | - Gianluca Ursini
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD, USA
| | - Yan Jouroukhin
- Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences SUNY, University at Buffalo, Buffalo, NY, USA
| | - Xiaolei Zhu
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Yu Miyahara
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Feiyi Xiong
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Samskruthi Madireddy
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Mizuho Obayashi
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Beat Lutz
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
- Leibniz Institute for Resilience Research (LIR) gGmbH, Mainz, Germany
| | - Akira Sawa
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Mental Health, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, USA
| | - Solange P Brown
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Kavli Neuroscience Discovery Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Mikhail V Pletnikov
- Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences SUNY, University at Buffalo, Buffalo, NY, USA.
| | - Atsushi Kamiya
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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19
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Karg MM, Moorefield M, Hoffmann E, Philipose H, Krasniqi D, Hoppe C, Shu DY, Shirahama S, Ksander BR, Saint-Geniez M. Microglia preserve visual function loss in the aging retina by supporting retinal pigment epithelial health. Immun Ageing 2023; 20:53. [PMID: 37838654 PMCID: PMC10576380 DOI: 10.1186/s12979-023-00358-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 06/23/2023] [Indexed: 10/16/2023]
Abstract
BACKGROUND Increased age is a risk factor for the development and progression of retinal diseases including age-related macular degeneration (AMD). Understanding the changes that occur in the eye due to aging is important in enhancing our understanding of AMD pathogenesis and the development of novel AMD therapies. Microglia, the resident brain and retinal immune cells are associated with both maintaining homeostasis and protection of neurons and loss of microglia homeostasis could be a significant player in age related neurodegeneration. One important characteristic of retinal aging is the migration of microglia from the inner to outer retina where they reside in the subretinal space (SRS) in contact with the retinal pigment epithelial (RPE) cells. The role of aged subretinal microglia is unknown. Here, we depleted microglia in aged C57/BL6 mice fed for 6 weeks with a chow containing PLX5622, a small molecule inhibitor of colony-stimulating factor-1 receptor (Csf1r) required for microglial survival. RESULTS The subretinal P2RY12 + microglia in aged mice displayed a highly amoeboid and activated morphology and were filled with autofluorescence droplets reminiscent of lipofuscin. TEM indicates that subretinal microglia actively phagocytize shed photoreceptor outer segments, one of the main functions of retinal pigmented epithelial cells. PLX5622 treatment depleted up to 90% of the retinal microglia and was associated with significant loss in visual function. Mice on the microglia depletion diet showed reduced contrast sensitivity and significantly lower electroretinogram for the c-wave, a measurement of RPE functionality, compared to age-matched controls. The loss of c-wave coincided with a loss of RPE cells and increased RPE swelling in the absence of microglia. CONCLUSIONS We conclude that microglia preserve visual function in aged mice and support RPE cell function, by phagocytosing shed photoreceptor outer segments and lipids, therefore compensating for the known age-related decline of RPE phagocytosis.
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Affiliation(s)
- Margarete M Karg
- Schepens Eye Research Institute of Mass Eye and Ear, 20 Staniford St, Boston, MA, 02114, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - May Moorefield
- Schepens Eye Research Institute of Mass Eye and Ear, 20 Staniford St, Boston, MA, 02114, USA
| | - Emma Hoffmann
- Schepens Eye Research Institute of Mass Eye and Ear, 20 Staniford St, Boston, MA, 02114, USA
| | - Hannah Philipose
- Schepens Eye Research Institute of Mass Eye and Ear, 20 Staniford St, Boston, MA, 02114, USA
| | - Drenushe Krasniqi
- Schepens Eye Research Institute of Mass Eye and Ear, 20 Staniford St, Boston, MA, 02114, USA
| | - Cindy Hoppe
- Schepens Eye Research Institute of Mass Eye and Ear, 20 Staniford St, Boston, MA, 02114, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Daisy Y Shu
- Schepens Eye Research Institute of Mass Eye and Ear, 20 Staniford St, Boston, MA, 02114, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Shintaro Shirahama
- Schepens Eye Research Institute of Mass Eye and Ear, 20 Staniford St, Boston, MA, 02114, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Bruce R Ksander
- Schepens Eye Research Institute of Mass Eye and Ear, 20 Staniford St, Boston, MA, 02114, USA.
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA.
| | - Magali Saint-Geniez
- Schepens Eye Research Institute of Mass Eye and Ear, 20 Staniford St, Boston, MA, 02114, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
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20
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Ritzel RM, Li Y, Jiao Y, Doran SJ, Khan N, Henry RJ, Brunner K, Loane DJ, Faden AI, Szeto GL, Wu J. The brain-bone marrow axis and its implications for chronic traumatic brain injury. RESEARCH SQUARE 2023:rs.3.rs-3356007. [PMID: 37790560 PMCID: PMC10543403 DOI: 10.21203/rs.3.rs-3356007/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Traumatic brain injury (TBI) causes acute and chronic alterations in systemic immune function which contribute to posttraumatic neuroinflammation and neurodegeneration. However, how TBI affects bone marrow (BM) hematopoietic stem/progenitor cells chronically and to what extent such changes may negatively impact innate immunity and neurological function has not been examined. To further understand the role of BM cell derivatives on TBI outcome, we generated BM chimeric mice by transplanting BM from chronically injured or sham congenic donor mice into otherwise healthy, age-matched, irradiated hosts. After 8 weeks of reconstitution, peripheral myeloid cells from TBI→WT mice showed significantly higher oxidative stress levels and reduced phagocytic activity. At eight months after reconstitution, TBI→WT chimeric mice were leukopenic, with continued alterations in phagocytosis and oxidative stress responses, as well as persistent neurological deficits. Gene expression analysis revealed BM-driven changes in neuroinflammation and neuropathology after 8 weeks and 8 months of reconstitution, respectively. Chimeric mice subjected to TBI showed that longer reconstitution periods were associated with increased microgliosis and leukocyte infiltration. Thus, TBI causes chronic activation and progressive dysfunction of the BM stem/progenitor cell pool, which drives long-term deficits in innate immunity and neurological function, as well as altered sensitivity to subsequent brain injury.
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Affiliation(s)
- Rodney M. Ritzel
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, Texas, USA
| | - Yun Li
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Yun Jiao
- Department of Chemical, Biochemical and Environmental Engineering, University of Maryland, Baltimore County, Maryland, USA
| | - Sarah J. Doran
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Niaz Khan
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Rebecca J. Henry
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Kavitha Brunner
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - David J. Loane
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Alan I. Faden
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Gregory L. Szeto
- Department of Chemical, Biochemical and Environmental Engineering, University of Maryland, Baltimore County, Maryland, USA
| | - Junfang Wu
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, Maryland, USA
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21
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Rubin LH, Du Y, Sweeney SE, O’Toole R, Thomas CL, Zandi AG, Shinehouse LK, Brosnan MK, Nam H, Burke ME, Bureau SC, Kilgore JJ, Yoon M, Soule AR, Lesniak WG, Minn I, Rowe SP, Holt DP, Hall AW, Mathews WB, Smith GS, Nowinski CJ, Kassiou M, Dannals RF, Pomper MG, Coughlin JM. Imaging Brain Injury in Former National Football League Players. JAMA Netw Open 2023; 6:e2340580. [PMID: 37902750 PMCID: PMC10616723 DOI: 10.1001/jamanetworkopen.2023.40580] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 09/15/2023] [Indexed: 10/31/2023] Open
Abstract
Importance Pilot studies that involved early imaging of the 18 kDa translocator protein (TSPO) using positron emission tomography (PET) indicated high levels of TSPO in the brains of active or former National Football League (NFL) players. If validated further in larger studies, those findings may have implications for athletes involved in collision sport. Objective To test for higher TSPO that marks brain injury and repair in a relatively large, unique cohort of former NFL players compared with former elite, noncollision sport athletes. Design, Setting, and Participants This cross-sectional study used carbon 11-labeled N,N-diethyl-2-(4-methoxyphenyl)-5,7-dimethylpyrazolo[1,5-a]pyrimidine-3-acetamide positron emission tomography ([11C]DPA-713 PET) data from former NFL players within 12 years of last participation in the NFL and elite noncollision sport athletes from across the US. Participants were enrolled between April 2018 and February 2023. Main outcomes and measures Regional [11C]DPA-713 total distribution volume from [11C]DPA-713 PET that is a measure of regional brain TSPO; regional brain volumes on magnetic resonance imaging; neuropsychological performance, including attention, executive function, and memory domains. Results This study included 27 former NFL players and 27 former elite, noncollision sport athletes. Regional TSPO levels were higher in former NFL players compared with former elite, noncollision sport athletes (unstandardized β coefficient, 1.08; SE, 0.22; 95% CI, 0.65 to 1.52; P < .001). The magnitude of the group difference depended on region, with largest group differences in TSPO in cingulate and frontal cortices as well as hippocampus. Compared with noncollision sport athletes, former NFL players performed worse in learning (mean difference [MD], -0.70; 95% CI, -1.14 to -0.25; P = .003) and memory (MD, -0.77; 95% CI, -1.24 to -0.30; P = .002), with no correlation between total gray matter TSPO and these cognitive domains. Conclusions and relevance In this cross-sectional study using [11C]DPA-713 PET, higher brain TSPO was found in former NFL players compared with noncollision sport athletes. This finding is consistent with neuroimmune activation even after cessation of NFL play. Future longitudinal [11C]DPA-713 PET and neuropsychological testing promises to inform whether neuroimmune-modulating therapy may be warranted.
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Affiliation(s)
- Leah H. Rubin
- Department of Neurology, Johns Hopkins Medical Institutions, Baltimore, Maryland
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland
- Department of Epidemiology, Johns Hopkins Medical Institutions, Baltimore, Maryland
- Department of Molecular and Comparative Pathobiology, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Yong Du
- Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Shannon Eileen Sweeney
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Riley O’Toole
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Cykyra L. Thomas
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Adeline G. Zandi
- Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Laura K. Shinehouse
- Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Mary Katherine Brosnan
- Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Hwanhee Nam
- Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | | | | | - Jessica J. Kilgore
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Mark Yoon
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Ana R. Soule
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Wojciech G. Lesniak
- Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Il Minn
- Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Steven P. Rowe
- Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Daniel P. Holt
- Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Andrew W. Hall
- Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - William B. Mathews
- Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Gwenn S. Smith
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Christopher J. Nowinski
- Concussion Legacy Foundation, Boston, Massachusetts
- Alzheimer’s Disease and CTE Center, Boston University School of Medicine, Boston, Massachusetts
| | - Michael Kassiou
- School of Chemistry, University of Sydney, Sydney, New South Wales, Australia
| | - Robert F. Dannals
- Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Martin G. Pomper
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland
- Department of Molecular and Comparative Pathobiology, Johns Hopkins Medical Institutions, Baltimore, Maryland
- Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Jennifer M. Coughlin
- Department of Neurology, Johns Hopkins Medical Institutions, Baltimore, Maryland
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland
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22
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Strogulski NR, Portela LV, Polster BM, Loane DJ. Fundamental Neurochemistry Review: Microglial immunometabolism in traumatic brain injury. J Neurochem 2023; 167:129-153. [PMID: 37759406 PMCID: PMC10655864 DOI: 10.1111/jnc.15959] [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: 07/05/2023] [Revised: 08/28/2023] [Accepted: 08/29/2023] [Indexed: 09/29/2023]
Abstract
Traumatic brain injury (TBI) is a devastating neurological disorder caused by a physical impact to the brain that promotes diffuse damage and chronic neurodegeneration. Key mechanisms believed to support secondary brain injury include mitochondrial dysfunction and chronic neuroinflammation. Microglia and brain-infiltrating macrophages are responsible for neuroinflammatory cytokine and reactive oxygen species (ROS) production after TBI. Their production is associated with loss of homeostatic microglial functions such as immunosurveillance, phagocytosis, and immune resolution. Beyond providing energy support, mitochondrial metabolic pathways reprogram the pro- and anti-inflammatory machinery in immune cells, providing a critical immunometabolic axis capable of regulating immunologic response to noxious stimuli. In the brain, the capacity to adapt to different environmental stimuli derives, in part, from microglia's ability to recognize and respond to changes in extracellular and intracellular metabolite levels. This capacity is met by an equally plastic metabolism, capable of altering immune function. Microglial pro-inflammatory activation is associated with decreased mitochondrial respiration, whereas anti-inflammatory microglial polarization is supported by increased oxidative metabolism. These metabolic adaptations contribute to neuroimmune responses, placing mitochondria as a central regulator of post-traumatic neuroinflammation. Although it is established that profound neurometabolic changes occur following TBI, key questions related to metabolic shifts in microglia remain unresolved. These include (a) the nature of microglial mitochondrial dysfunction after TBI, (b) the hierarchical positions of different metabolic pathways such as glycolysis, pentose phosphate pathway, glutaminolysis, and lipid oxidation during secondary injury and recovery, and (c) how immunometabolism alters microglial phenotypes, culminating in chronic non-resolving neuroinflammation. In this basic neurochemistry review article, we describe the contributions of immunometabolism to TBI, detail primary evidence of mitochondrial dysfunction and metabolic impairments in microglia and macrophages, discuss how major metabolic pathways contribute to post-traumatic neuroinflammation, and set out future directions toward advancing immunometabolic phenotyping in TBI.
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Affiliation(s)
- Nathan R. Strogulski
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | - Luis V. Portela
- Neurotrauma and Biomarkers Laboratory, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Brian M. Polster
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research Center, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - David J. Loane
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research Center, University of Maryland School of Medicine, Baltimore, Maryland, USA
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23
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Bergold PJ, Furhang R, Lawless S. Treating Traumatic Brain Injury with Minocycline. Neurotherapeutics 2023; 20:1546-1564. [PMID: 37721647 PMCID: PMC10684850 DOI: 10.1007/s13311-023-01426-9] [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] [Accepted: 08/16/2023] [Indexed: 09/19/2023] Open
Abstract
Traumatic brain injury (TBI) results in both rapid and delayed brain damage. The speed, complexity, and persistence of TBI present large obstacles to drug development. Preclinical studies from multiple laboratories have tested the FDA-approved anti-microbial drug minocycline (MINO) to treat traumatic brain injury. At concentrations greater than needed for anti-microbial action, MINO readily inhibits microglial activation. MINO has additional pleotropic effects including anti-inflammatory, anti-oxidant, and anti-apoptotic activities. MINO inhibits multiple proteins that promote brain injury including metalloproteases, caspases, calpain, and polyADP-ribose-polymerase-1. At these elevated doses, MINO is well tolerated and enters the brain even when the blood-brain barrier is intact. Most preclinical studies with a first dose of MINO at less than 1 h after injury have shown improved multiple outcomes after TBI. Fewer studies with more delayed dosing have yielded similar results. A small number of clinical trials for TBI have established the safety of MINO and suggested some drug efficacy. Studies are also ongoing that either improve MINO pharmacology or combine MINO with other drugs to increase its therapeutic efficacy against TBI. This review builds upon a previous, recent review by some of the authors (Lawless and Bergold, Neural Regen Res 17:2589-92, 2022). The present review includes the additional preclinical studies examining the efficacy of minocycline in preclinical TBI models. This review also includes recommendations for a clinical trial to test MINO to treat TBI.
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Affiliation(s)
- Peter J Bergold
- Graduate Programs in Neural and Behavioral Sciences, State University of New York Downstate Health Sciences University, 450 Clarkson Avenue, Brooklyn, New York, NY, 11203, USA.
- Department of Physiology and Pharmacology, State University of New York Downstate Health Sciences University, 450 Clarkson Avenue, Brooklyn, New York, NY, 11203, USA.
| | - Rachel Furhang
- Graduate Programs in Neural and Behavioral Sciences, State University of New York Downstate Health Sciences University, 450 Clarkson Avenue, Brooklyn, New York, NY, 11203, USA
| | - Siobhán Lawless
- Graduate Programs in Neural and Behavioral Sciences, State University of New York Downstate Health Sciences University, 450 Clarkson Avenue, Brooklyn, New York, NY, 11203, USA
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24
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Wellman SM, Coyne OA, Douglas MM, Kozai TDY. Aberrant accumulation of age- and disease-associated factors following neural probe implantation in a mouse model of Alzheimer's disease. J Neural Eng 2023; 20:046044. [PMID: 37531953 PMCID: PMC10594264 DOI: 10.1088/1741-2552/aceca5] [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: 02/16/2023] [Revised: 07/27/2023] [Accepted: 08/01/2023] [Indexed: 08/04/2023]
Abstract
Objective. Electrical stimulation has had a profound impact on our current understanding of nervous system physiology and provided viable clinical options for addressing neurological dysfunction within the brain. Unfortunately, the brain's immune suppression of indwelling microelectrodes currently presents a major roadblock in the long-term application of neural recording and stimulating devices. In some ways, brain trauma induced by penetrating microelectrodes produces similar neuropathology as debilitating brain diseases, such as Alzheimer's disease (AD), while also suffering from end-stage neuron loss and tissue degeneration. The goal of the present study was to understand whether there may be any parallel mechanisms at play between brain injury from chronic microelectrode implantation and those of neurodegenerative disorder.Approach. We used two-photon microscopy to visualize the accumulation, if any, of age- and disease-associated factors around chronically implanted electrodes in both young and aged mouse models of AD.Main results. We determined that electrode injury leads to aberrant accumulation of lipofuscin, an age-related pigment, in wild-type and AD mice alike. Furthermore, we reveal that chronic microelectrode implantation reduces the growth of pre-existing Alzheimer's plaques while simultaneously elevating amyloid burden at the electrode-tissue interface. Lastly, we uncover novel spatial and temporal patterns of glial reactivity, axonal and myelin pathology, and neurodegeneration related to neurodegenerative disease around chronically implanted microelectrodes.Significance. This study offers multiple novel perspectives on the possible neurodegenerative mechanisms afflicting chronic brain implants, spurring new potential avenues of neuroscience investigation and design of more targeted therapies for improving neural device biocompatibility and treatment of degenerative brain disease.
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Affiliation(s)
- Steven M Wellman
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America
- Center for Neural Basis of Cognition, Pittsburgh, PA, United States of America
| | - Olivia A Coyne
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America
- Center for Neural Basis of Cognition, Pittsburgh, PA, United States of America
| | - Madeline M Douglas
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Takashi D Y Kozai
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America
- Center for Neural Basis of Cognition, Pittsburgh, PA, United States of America
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States of America
- McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America
- NeuroTech Center, University of Pittsburgh Brain Institute, Pittsburgh, PA, United States of America
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25
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Hasegawa Y, Kim J, Ursini G, Jouroukhin Y, Zhu X, Miyahara Y, Xiong F, Madireddy S, Obayashi M, Lutz B, Sawa A, Brown SP, Pletnikov MV, Kamiya A. Microglial cannabinoid receptor type 1 mediates social memory deficits produced by adolescent THC exposure and 16p11.2 duplication. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.24.550212. [PMID: 37546830 PMCID: PMC10402026 DOI: 10.1101/2023.07.24.550212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Adolescent cannabis use increases the risk for cognitive impairments and psychiatric disorders. Cannabinoid receptor type 1 (Cnr1) is expressed not only in neurons and astrocytes, but also in microglia, which shape synaptic connections during adolescence. Nonetheless, until now, the role of microglia in mediating the adverse cognitive effects of delta-9-tetrahydrocannabinol (THC), the principal psychoactive constituent of cannabis, has been unexplored. Here, we report that adolescent THC exposure produces microglial apoptosis in the medial prefrontal cortex (mPFC), which was exacerbated in the mouse model of 16p11.2 duplication, a representative copy number variation (CNV) risk factor for psychiatric disorders. These effects are mediated by microglial Cnr1, leading to reduction in the excitability of mPFC pyramidal-tract neurons and deficits in social memory in adulthood. Our findings highlight the importance of microglial Cnr1 to produce the adverse effect of cannabis exposure in genetically vulnerable individuals.
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