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van Hameren G, Aboghazleh R, Parker E, Dreier JP, Kaufer D, Friedman A. From spreading depolarization to blood-brain barrier dysfunction: navigating traumatic brain injury for novel diagnosis and therapy. Nat Rev Neurol 2024; 20:408-425. [PMID: 38886512 DOI: 10.1038/s41582-024-00973-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/08/2024] [Indexed: 06/20/2024]
Abstract
Considerable strides in medical interventions during the acute phase of traumatic brain injury (TBI) have brought improved overall survival rates. However, following TBI, people often face ongoing, persistent and debilitating long-term complications. Here, we review the recent literature to propose possible mechanisms that lead from TBI to long-term complications, focusing particularly on the involvement of a compromised blood-brain barrier (BBB). We discuss evidence for the role of spreading depolarization as a key pathological mechanism associated with microvascular dysfunction and the transformation of astrocytes to an inflammatory phenotype. Finally, we summarize new predictive and diagnostic biomarkers and explore potential therapeutic targets for treating long-term complications of TBI.
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Affiliation(s)
- Gerben van Hameren
- Department of Medical Neuroscience, Faculty of Medicine and Brain Repair Center, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Refat Aboghazleh
- Department of Medical Neuroscience, Faculty of Medicine and Brain Repair Center, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Basic Medical Sciences, Faculty of Medicine, Al-Balqa Applied University, Al-Salt, Jordan
| | - Ellen Parker
- Department of Medical Neuroscience, Faculty of Medicine and Brain Repair Center, Dalhousie University, Halifax, Nova Scotia, Canada
- Division of Neurosurgery, Dalhousie University QEII Health Sciences Centre, Nova Scotia Health Authority, Halifax, Nova Scotia, Canada
| | - Jens P Dreier
- Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany
- Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany
- Einstein Center for Neurosciences Berlin, Berlin, Germany
- Center for Stroke Research Berlin, Charité - Universitätsmedizin Berlin, Berlin, Germany
- Department of Experimental Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Daniela Kaufer
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Alon Friedman
- Department of Medical Neuroscience, Faculty of Medicine and Brain Repair Center, Dalhousie University, Halifax, Nova Scotia, Canada.
- Department of Cell Biology, Cognitive and Brain Sciences, Zelman Inter-Disciplinary Center of Brain Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
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2
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Li Y, Liu C, Chen Z, Lin H, Li X. Netrin-1 protects blood-brain barrier (BBB) integrity after cerebral ischemia-reperfusion by activating the Kruppel-like factor 2 (KLF2)/occludin pathway. J Biochem Mol Toxicol 2024; 38:e23623. [PMID: 38229322 DOI: 10.1002/jbt.23623] [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: 09/09/2023] [Revised: 11/04/2023] [Accepted: 12/14/2023] [Indexed: 01/18/2024]
Abstract
Ischemia/reperfusion (I/R)-induced neural damage and neuroinflammation have been associated with pathological progression during stroke. Netrin-1 is an important member of the family of laminin-related secreted proteins, which plays an important role in governing axon elongation. However, it is unknown whether Netrin-1 possesses a beneficial role in stroke. Here, we employed the middle cerebral artery occlusion (MCAO) model to study the function of Netrin-1 in alleviating brain injuries. Our results demonstrate that Netrin-1 rescued poststroke neurological deficits and inhibited production of the inflammatory cytokines such as interleukin 6 (IL-6) and endothelial chemokine (C-X-C motif) ligand 1 (Cxcl1). Importantly, Netrin-1 protected against MCAO-induced dysfunction of the blood-brain barrier (BBB) in mice and a reduction in the expression of the tight junction (TJ) protein occludin. Additionally, we report that Netrin-1 could ameliorate oxygen-glucose deprivation/reoxygenation (OGD/R)-induced injury and prevent aggravation in endothelial monolayer permeability in bEnd.3 human brain microvascular endothelial cells (HBMVECs). Mechanistically, Netrin-1 ameliorated OGD/R-induced decrease in occludin and Kruppel-like factor 2 (KLF2) in HBMVECs. Notably, silencing of KLF2 abolished the beneficial effects of Netrin-1 in protecting endothelial permeability and occludin expression, suggesting that these effects are mediated by KLF2. In conclusion, our findings suggest that Netrin-1 could constitute a novel therapeutic strategy for ischemic stroke.
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Affiliation(s)
- Yuanxiao Li
- Department of Neurology, Fujian Medical University Union Hospital, Fuzhou, Fujian Province, China
| | - Changyun Liu
- Department of Neurology, Fujian Medical University Union Hospital, Fuzhou, Fujian Province, China
| | - Zhiting Chen
- Department of Neurology, Fujian Medical University Union Hospital, Fuzhou, Fujian Province, China
| | - Hanbin Lin
- Department of Neurology, Fujian Medical University Union Hospital, Fuzhou, Fujian Province, China
| | - Xiaofeng Li
- Department of Neurology, Fujian Medical University Union Hospital, Fuzhou, Fujian Province, China
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3
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Jiang L, Li F, Chen Z, Zhu B, Yi C, Li Y, Zhang T, Peng Y, Si Y, Cao Z, Chen A, Yao D, Chen X, Xu P. Information transmission velocity-based dynamic hierarchical brain networks. Neuroimage 2023; 270:119997. [PMID: 36868393 DOI: 10.1016/j.neuroimage.2023.119997] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 02/09/2023] [Accepted: 02/27/2023] [Indexed: 03/05/2023] Open
Abstract
The brain functions as an accurate circuit that regulates information to be sequentially propagated and processed in a hierarchical manner. However, it is still unknown how the brain is hierarchically organized and how information is dynamically propagated during high-level cognition. In this study, we developed a new scheme for quantifying the information transmission velocity (ITV) by combining electroencephalogram (EEG) and diffusion tensor imaging (DTI), and then mapped the cortical ITV network (ITVN) to explore the information transmission mechanism of the human brain. The application in MRI-EEG data of P300 revealed bottom-up and top-down ITVN interactions subserving P300 generation, which was comprised of four hierarchical modules. Among these four modules, information exchange between visual- and attention-activated regions occurred at a high velocity, related cognitive processes could thus be efficiently accomplished due to the heavy myelination of these regions. Moreover, inter-individual variability in P300 was probed to be attributed to the difference in information transmission efficiency of the brain, which may provide new insight into the cognitive degenerations in clinical neurodegenerative disorders, such as Alzheimer's disease, from the transmission velocity perspective. Together, these findings confirm the capacity of ITV to effectively determine the efficiency of information propagation in the brain.
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Affiliation(s)
- Lin Jiang
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, Sichuan 611731, China; School of Life Science and Technology, Center for Information in BioMedicine, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Fali Li
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, Sichuan 611731, China; School of Life Science and Technology, Center for Information in BioMedicine, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Zhaojin Chen
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, Sichuan 611731, China; School of Life Science and Technology, Center for Information in BioMedicine, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Bin Zhu
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, Sichuan 611731, China; School of Life Science and Technology, Center for Information in BioMedicine, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Chanlin Yi
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, Sichuan 611731, China; School of Life Science and Technology, Center for Information in BioMedicine, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Yuqin Li
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, Sichuan 611731, China; School of Life Science and Technology, Center for Information in BioMedicine, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Tao Zhang
- School of science, Xihua University, Chengdu 610039, China
| | - Yueheng Peng
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, Sichuan 611731, China; School of Life Science and Technology, Center for Information in BioMedicine, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Yajing Si
- School of Psychology, Xinxiang Medical University, Xinxiang 453003, China
| | - Zehong Cao
- STEM, University of South Australia, Adelaide, SA 5000, Australia
| | - Antao Chen
- Faculty of Psychology, Southwest University, Chongqing 400715, China
| | - Dezhong Yao
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, Sichuan 611731, China; School of Life Science and Technology, Center for Information in BioMedicine, University of Electronic Science and Technology of China, Chengdu 611731, China; School of Electrical Engineering, Zhengzhou University, Zhengzhou 450001, China; Research Unit of NeuroInformation, Chinese Academy of Medical Sciences, Chengdu 2019RU035, China.
| | - Xun Chen
- Department of Neurosurgery, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230001, China; Department of Electronic Engineering and Information Science, University of Science and Technology of China, Hefei 230026, China.
| | - Peng Xu
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, Sichuan 611731, China; School of Life Science and Technology, Center for Information in BioMedicine, University of Electronic Science and Technology of China, Chengdu 611731, China.
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4
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Chakraborty R, Tabassum H, Parvez S. NLRP3 inflammasome in traumatic brain injury: Its implication in the disease pathophysiology and potential as a therapeutic target. Life Sci 2023; 314:121352. [PMID: 36592789 DOI: 10.1016/j.lfs.2022.121352] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 12/18/2022] [Accepted: 12/27/2022] [Indexed: 12/31/2022]
Abstract
Traumatic brain injury (TBI), an acquired brain injury imparted by a mechanical trauma to the head, has significant ramifications in terms of long-term disability and cost of healthcare. TBI is characterized by an initial phase of cell death owing to direct mechanical injury, followed by a secondary phase in which neuroinflammation plays a pivotal role. Activation of inflammasome complexes triggers a cascade that leads to activation of inflammatory mediators such as caspase-1, Interleukin (IL)-18, and IL-1β, eventually causing pyroptosis. NLRP3 inflammasome, a component of the innate immune response, has been implicated in a number of neurodegenerative diseases, including TBI. Recent findings indicate that NLRP3 inhibitors can potentially ameliorate neuroinflammation and improve cognition and motor function in TBI. The NLRP3 inflammasome also holds potential as a predictive biomarker for the long-term sequelae following TBI. Although several therapeutic agents have shown promising results in pre-clinical studies, none of them have been effective in human trials for TBI, to date. Thus, it is imperative that such promising therapeutic candidates are evaluated in clinical trials to assess their efficacy in alleviating neurological impairments in TBI. This review offers an insight into the pathophysiology of TBI, with an emphasis on neuroinflammation in the aftermath of TBI. We highlight the NLRP3 inflammasome and explore its role in the neuroinflammatory cascade in TBI. We also shed light on its potential as a prospective biomarker and therapeutic target for TBI management.
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Affiliation(s)
- Rohan Chakraborty
- Department of Toxicology, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi 110062, India
| | - Heena Tabassum
- Division of Basic Medical Sciences, Indian Council of Medical Research, Ministry of Health and Family Welfare, Govt. of India, V. Ramalingaswami Bhawan, P.O. Box No. 4911, New Delhi 110029, India
| | - Suhel Parvez
- Department of Toxicology, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi 110062, India.
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5
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Adegoke MA, Teter O, Meaney DF. Flexibility of in vitro cortical circuits influences resilience from microtrauma. Front Cell Neurosci 2022; 16:991740. [PMID: 36589287 PMCID: PMC9803265 DOI: 10.3389/fncel.2022.991740] [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: 07/11/2022] [Accepted: 11/28/2022] [Indexed: 12/23/2022] Open
Abstract
Background Small clusters comprising hundreds to thousands of neurons are an important level of brain architecture that correlates single neuronal properties to fulfill brain function, but the specific mechanisms through which this scaling occurs are not well understood. In this study, we developed an in vitro experimental platform of small neuronal circuits (islands) to probe the importance of structural properties for their development, physiology, and response to microtrauma. Methods Primary cortical neurons were plated on a substrate patterned to promote attachment in clusters of hundreds of cells (islands), transduced with GCaMP6f, allowed to mature until 10-13 days in vitro (DIV), and monitored with Ca2+ as a non-invasive proxy for electrical activity. We adjusted two structural factors-island size and cellular density-to evaluate their role in guiding spontaneous activity and network formation in neuronal islands. Results We found cellular density, but not island size, regulates of circuit activity and network function in this system. Low cellular density islands can achieve many states of activity, while high cellular density biases islands towards a limited regime characterized by low rates of activity and high synchronization, a property we summarized as "flexibility." The injury severity required for an island to lose activity in 50% of its population was significantly higher in low-density, high flexibility islands. Conclusion Together, these studies demonstrate flexible living cortical circuits are more resilient to microtrauma, providing the first evidence that initial circuit state may be a key factor to consider when evaluating the consequences of trauma to the cortex.
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Affiliation(s)
- Modupe A. Adegoke
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, PA, United States
| | - Olivia Teter
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, PA, United States
| | - David F. Meaney
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, PA, United States,Department of Neurosurgery, Penn Center for Brain Injury and Repair, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States,*Correspondence: David F. Meaney,
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6
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Chen X, Liu F, Li B, Wang Y, Yuan L, Yin A, Chen Q, Hu W, Yao Y, Zhang M, Wu Y, Chen K. Neuropathy-associated Fars2 deficiency affects neuronal development and potentiates neuronal apoptosis by impairing mitochondrial function. Cell Biosci 2022; 12:103. [PMID: 35794642 PMCID: PMC9258231 DOI: 10.1186/s13578-022-00838-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Accepted: 06/23/2022] [Indexed: 11/22/2022] Open
Abstract
Background Neurodegenerative diseases encompass an extensive and heterogeneous group of nervous system disorders which are characterized by progressive degeneration and death of neurons. Many lines of evidence suggest the participation of mitochondria dysfunction in these diseases. Mitochondrial phenylalanyl-tRNA synthetase, encoded by FARS2, catalyzes the transfer of phenylalanine to its cognate tRNA for protein synthesis. As a member of mt-aaRSs genes, FARS2 missense homozygous mutation c.424G > T (p.D142Y) found in a Chinese consanguineous family first built the relationship between pure hereditary spastic paraplegia (HSP) and FARS2 gene. More FARS2 variations were subsequently found to cause heterogeneous group of neurologic disorders presenting three main phenotypic manifestations: infantile-onset epileptic mitochondrial encephalopathy, later-onset spastic paraplegia and juvenile onset refractory epilepsy. Studies showed that aminoacylation activity is frequently disrupt in cases with FARS2 mutations, indicating a loss-of-function mechanism. However, the underlying pathogenesis of neuropathy-associated Fars2 deficiency is still largely unknown. Results Early gestation lethality of global Fars2 knockout mice was observed prior to neurogenesis. The conditional Fars2 knockout-mouse model delayed lethality to late-gestation, resulting in a thinner cortex and an enlarged ventricle which is consist with the MRI results revealing cortical atrophy and reduced cerebral white matter volume in FARS2-deficient patients. Delayed development of neurite outgrowth followed by neuronal apoptosis was confirmed in Fars2-knockdown mouse primary cultured neurons. Zebrafish, in which fars2 was knocked down, exhibited aberrant motor neuron function including reduced locomotor capacity which well restored the spastic paraplegia phenotype of FARS2-deficient patients. Altered mitochondrial protein synthesis and reduced levels of oxidative phosphorylation complexes were detected in Fars2-deficient samples. And thus, reduced ATP, total NAD levels and mitochondrial membrane potential, together with increased ROS production, revealed mitochondrial dysfunction both in vitro and in vivo. Dctn3 is a potential downstream molecule in responds to Fars2 deficient in neurons, which may provide some evidence for the development of pathogenesis study and therapeutic schedule. Conclusions The Fars2 deficiency genetic models developed in this study cover the typical clinical manifestations in FARS2 patients, and help clarify how neuropathy-associated Fars2 deficiency, by damaging the mitochondrial respiratory chain and impairing mitochondrial function, affects neuronal development and potentiates neuronal cell apoptosis. Supplementary Information The online version contains supplementary material available at 10.1186/s13578-022-00838-y.
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Affiliation(s)
- Xihui Chen
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China.,Shaanxi Provincial Key Laboratory of Clinic Genetics, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China
| | - Fangfang Liu
- Department of Neurobiology, School of Basic Medicine, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China
| | - Bowen Li
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China.,Shaanxi Provincial Key Laboratory of Clinic Genetics, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China
| | - Yufeng Wang
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China.,Shaanxi Provincial Key Laboratory of Clinic Genetics, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China.,Medical Genetics, Yan'an University, Yan'an, Shaanxi, People's Republic of China
| | - Lijuan Yuan
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China.,Shaanxi Provincial Key Laboratory of Clinic Genetics, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China.,Department of General Surgery, Tangdu Hospital, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China
| | - Anan Yin
- Department of Neurosurgery, Xijing Institute of Clinical Neuroscience, Department of Plastic surgery, Xijing Hospital, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China
| | - Qi Chen
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China.,Shaanxi Provincial Key Laboratory of Clinic Genetics, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China
| | - Weihong Hu
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China.,Shaanxi Provincial Key Laboratory of Clinic Genetics, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China.,Medical Genetics, Yan'an University, Yan'an, Shaanxi, People's Republic of China
| | - Yan Yao
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China.,Shaanxi Provincial Key Laboratory of Clinic Genetics, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China.,Medical Genetics, Yan'an University, Yan'an, Shaanxi, People's Republic of China
| | - Mengjie Zhang
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China.,Shaanxi Provincial Key Laboratory of Clinic Genetics, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China.,Medical Genetics, Yan'an University, Yan'an, Shaanxi, People's Republic of China
| | - YuanMing Wu
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China. .,Shaanxi Provincial Key Laboratory of Clinic Genetics, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China.
| | - Kun Chen
- Department of Anatomy, Histology and Embryology and K.K. Leung Brain Research Centre, School of Basic Medicine, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China.
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7
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Mechanisms Involved in Epileptogenesis in Alzheimer's Disease and Their Therapeutic Implications. Int J Mol Sci 2022; 23:ijms23084307. [PMID: 35457126 PMCID: PMC9030029 DOI: 10.3390/ijms23084307] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Revised: 04/09/2022] [Accepted: 04/11/2022] [Indexed: 12/22/2022] Open
Abstract
Epilepsy and Alzheimer's disease (AD) incidence increases with age. There are reciprocal relationships between epilepsy and AD. Epilepsy is a risk factor for AD and, in turn, AD is an independent risk factor for developing epilepsy in old age, and abnormal AD biomarkers in PET and/or CSF are frequently found in late-onset epilepsies of unknown etiology. Accordingly, epilepsy and AD share pathophysiological processes, including neuronal hyperexcitability and an early excitatory-inhibitory dysregulation, leading to dysfunction in the inhibitory GABAergic and excitatory glutamatergic systems. Moreover, both β-amyloid and tau protein aggregates, the anatomopathological hallmarks of AD, have proepileptic effects. Finally, these aggregates have been found in the resection material of refractory temporal lobe epilepsies, suggesting that epilepsy leads to amyloid and tau aggregates. Some epileptic syndromes, such as medial temporal lobe epilepsy, share structural and functional neuroimaging findings with AD, leading to overlapping symptomatology, such as episodic memory deficits and toxic synergistic effects. In this respect, the existence of epileptiform activity and electroclinical seizures in AD appears to accelerate the progression of cognitive decline, and the presence of cognitive decline is much more prevalent in epileptic patients than in elderly patients without epilepsy. Notwithstanding their clinical significance, the diagnosis of clinical seizures in AD is a challenge. Most are focal and manifest with an altered level of consciousness without motor symptoms, and are often interpreted as cognitive fluctuations. Finally, despite the frequent association of epilepsy and AD dementia, there is a lack of clinical trials to guide the use of antiseizure medications (ASMs). There is also a potential role for ASMs to be used as disease-modifying drugs in AD.
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8
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Reduced hippocampal inhibition and enhanced autism-epilepsy comorbidity in mice lacking neuropilin 2. Transl Psychiatry 2021; 11:537. [PMID: 34663783 PMCID: PMC8523694 DOI: 10.1038/s41398-021-01655-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 08/18/2021] [Accepted: 09/17/2021] [Indexed: 12/19/2022] Open
Abstract
The neuropilin receptors and their secreted semaphorin ligands play key roles in brain circuit development by regulating numerous crucial neuronal processes, including the maturation of synapses and migration of GABAergic interneurons. Consistent with its developmental roles, the neuropilin 2 (Nrp2) locus contains polymorphisms in patients with autism spectrum disorder (ASD). Nrp2-deficient mice show autism-like behavioral deficits and propensity to develop seizures. In order to determine the pathophysiology in Nrp2 deficiency, we examined the hippocampal numbers of interneuron subtypes and inhibitory regulation of hippocampal CA1 pyramidal neurons in mice lacking one or both copies of Nrp2. Immunostaining for interneuron subtypes revealed that Nrp2-/- mice have a reduced number of parvalbumin, somatostatin, and neuropeptide Y cells, mainly in CA1. Whole-cell recordings identified reduced firing and hyperpolarized shift in resting membrane potential in CA1 pyramidal neurons from Nrp2+/- and Nrp2-/- mice compared to age-matched wild-type controls indicating decrease in intrinsic excitability. Simultaneously, the frequency and amplitude of spontaneous inhibitory postsynaptic currents (sIPSCs) are reduced in Nrp2-deficient mice. A convulsive dose of kainic acid evoked electrographic and behavioral seizures with significantly shorter latency, longer duration, and higher severity in Nrp2-/- compared to Nrp2+/+ animals. Finally, Nrp2+/- and Nrp2-/- but not Nrp2+/+, mice have impaired cognitive flexibility demonstrated by reward-based reversal learning, a task associated with hippocampal circuit function. Together these data demonstrate a broad reduction in interneuron subtypes and compromised inhibition in CA1 of Nrp2-/- mice, which could contribute to the heightened seizure susceptibility and behavioral deficits consistent with an ASD/epilepsy phenotype.
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9
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Sternson SM, Bleakman D. Chemogenetics: drug-controlled gene therapies for neural circuit disorders. ACTA ACUST UNITED AC 2021; 6:1079-1094. [PMID: 34422319 PMCID: PMC8376173 DOI: 10.18609/cgti.2020.112] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Many patients with nervous system disorders have considerable unmet clinical needs or suffer debilitating drug side effects. A major limitation of exiting treatment approaches is that traditional small molecule pharmacotherapy lacks sufficient specificity to effectively treat many neurological diseases. Chemogenetics is a new gene therapy technology that targets an engineered receptor to cell types involved in nervous system dysfunction, enabling highly selective drug-controlled neuromodulation. Here, we discuss chemogenetic platforms and considerations for their potential application as human nervous system therapies.
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Affiliation(s)
- Scott M Sternson
- Janelia Research Campus, HHMI, 19700 Helix Dr. Ashburn, VA 20147, USA
| | - David Bleakman
- Redpin Therapeutics, 1329, Madison Avenue, Suite 125, New York, NY 10029, USA
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10
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Chen Y, Dai Z, Fan R, Mikulis DJ, Qiu J, Shen Z, Wang R, Lai L, Tang Y, Li Y, Jia Y, Yan G, Wu R. Glymphatic System Visualized by Chemical-Exchange-Saturation-Transfer Magnetic Resonance Imaging. ACS Chem Neurosci 2020; 11:1978-1984. [PMID: 32492333 DOI: 10.1021/acschemneuro.0c00222] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Dysfunction of the glymphatic system may play a significant role in the development of neurodegenerative diseases. However, in vivo imaging of the glymphatic system is challenging. In this study, we describe an unconventional MRI method for imaging the glymphatic system based on chemical exchange saturation transfer, which we tested in an in vivo porcine model of impaired glymphatic function. The blood, lymph, and cerebrospinal fluid (CSF) from one pig were used for testing the MRI effect in vitro at 7 Tesla (T). Unilateral deep cervical lymph node ligation models were then performed in 20 adult male Sprague-Dawley rats. The brains were scanned in vivo dynamically after surgery using the new MRI method. Behavioral tests were performed after each scanning session and the results were tested for correlations with the MRI signal intensity. Finally, the pathological assessment was conducted in the same brain slices. The special MRI effect in the lymph was evident at about 1.0 ppm in water and was distinguishable from those of blood and CSF. In the model group, the intensity of this MRI signal was significantly higher in the ipsilateral than in the contralateral hippocampus. The correlation between the signal abnormality and the behavioral score was significant (Pearson's, R2 = 0.9154, p < 0.005). We conclude that the novel MRI method can visualize the glymphatic system in vivo.
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Affiliation(s)
- Yuanfeng Chen
- Department of Radiology, the Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, P.R. China
| | - Zhuozhi Dai
- Department of Radiology, the Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, P.R. China
| | - Ruhang Fan
- Department of Pathology, Medical College of Shantou University, Guangdong, Shantou 515031, P.R. China
| | - David John Mikulis
- Division of Neuroradiology, Department of Medical Imaging, University Health Network, Toronto, Ontario M5T 2S7, Canada
| | - Jinming Qiu
- Department of Radiology, the Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, P.R. China
| | - Zhiwei Shen
- Department of Radiology, the Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, P.R. China
| | - Runrun Wang
- Department of Radiology, the Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, P.R. China
| | - Lihua Lai
- Department of Radiology, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, P. R. China
| | - Yanyan Tang
- Department of Radiology, the Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, P.R. China
| | - Yan Li
- Department of Radiology, the Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, P.R. China
| | - Yanlong Jia
- Department of Radiology, the Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, P.R. China
| | - Gen Yan
- Department of Radiology, the Second Affiliated Hospital of Xiamen Medical College, Xiamen, Fujian Province 361022, China
| | - Renhua Wu
- Department of Radiology, the Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, P.R. China
- Provincial Key Laboratory of Medical Molecular Imaging, Guangdong, Shantou 515041, P.R. China
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11
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Casillas‐Espinosa PM, Ali I, O'Brien TJ. Neurodegenerative pathways as targets for acquired epilepsy therapy development. Epilepsia Open 2020; 5:138-154. [PMID: 32524040 PMCID: PMC7278567 DOI: 10.1002/epi4.12386] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 02/13/2020] [Accepted: 02/24/2020] [Indexed: 12/16/2022] Open
Abstract
There is a growing body of clinical and experimental evidence that neurodegenerative diseases and epileptogenesis after an acquired brain insult may share common etiological mechanisms. Acquired epilepsy commonly develops as a comorbid condition in patients with neurodegenerative diseases such as Alzheimer's disease, although it is likely much under diagnosed in practice. Progressive neurodegeneration has also been described after traumatic brain injury, stroke, and other forms of brain insults. Moreover, recent evidence has shown that acquired epilepsy is often a progressive disorder that is associated with the development of drug resistance, cognitive decline, and worsening of other neuropsychiatric comorbidities. Therefore, new pharmacological therapies that target neurobiological pathways that underpin neurodegenerative diseases have potential to have both an anti-epileptogenic and disease-modifying effect on the seizures in patients with acquired epilepsy, and also mitigate the progressive neurocognitive and neuropsychiatric comorbidities. Here, we review the neurodegenerative pathways that are plausible targets for the development of novel therapies that could prevent the development or modify the progression of acquired epilepsy, and the supporting published experimental and clinical evidence.
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Affiliation(s)
- Pablo M. Casillas‐Espinosa
- Departments of Neuroscience and MedicineCentral Clinical SchoolMonash UniversityMelbourneVic.Australia
- Department of MedicineThe Royal Melbourne HospitalThe University of MelbourneMelbourneVic.Australia
| | - Idrish Ali
- Departments of Neuroscience and MedicineCentral Clinical SchoolMonash UniversityMelbourneVic.Australia
- Department of MedicineThe Royal Melbourne HospitalThe University of MelbourneMelbourneVic.Australia
| | - Terence J. O'Brien
- Departments of Neuroscience and MedicineCentral Clinical SchoolMonash UniversityMelbourneVic.Australia
- Department of MedicineThe Royal Melbourne HospitalThe University of MelbourneMelbourneVic.Australia
- Department of NeurologyThe Alfred HospitalMelbourneVic.Australia
- Department of NeurologyThe Royal Melbourne HospitalParkvilleVic.Australia
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12
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Sivandzade F, Alqahtani F, Cucullo L. Traumatic Brain Injury and Blood-Brain Barrier (BBB): Underlying Pathophysiological Mechanisms and the Influence of Cigarette Smoking as a Premorbid Condition. Int J Mol Sci 2020; 21:E2721. [PMID: 32295258 PMCID: PMC7215684 DOI: 10.3390/ijms21082721] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 04/10/2020] [Accepted: 04/12/2020] [Indexed: 12/19/2022] Open
Abstract
Traumatic brain injury (TBI) is among the most pressing global health issues and prevalent causes of cerebrovascular and neurological disorders all over the world. In addition to the brain injury, TBI may also alter the systemic immune response. Thus, TBI patients become vulnerable to infections, have worse neurological outcomes, and exhibit a higher rate of mortality and morbidity. It is well established that brain injury leads to impairments of the blood-brain barrier (BBB) integrity and function, contributing to the loss of neural tissue and affecting the response to neuroprotective drugs. Thus, stabilization/protection of the BBB after TBI could be a promising strategy to limit neuronal inflammation, secondary brain damage, and acute neurodegeneration. Herein, we present a review highlighting the significant post-traumatic effects of TBI on the cerebrovascular system. These include the loss of BBB integrity and selective permeability, impact on BBB transport mechanisms, post-traumatic cerebral edema formation, and significant pathophysiological factors that may further exacerbate post-traumatic BBB dysfunctions. Furthermore, we discuss the post-traumatic impacts of chronic smoking, which has been recently shown to act as a premorbid condition that impairs post-TBI recovery. Indeed, understanding the underlying molecular mechanisms associated with TBI damage is essential to better understand the pathogenesis and progression of post-traumatic secondary brain injury and the development of targeted treatments to improve outcomes and speed up the recovery process. Therapies aimed at restoring/protecting the BBB may reduce the post-traumatic burden of TBI by minimizing the impairment of brain homeostasis and help to restore an optimal microenvironment to support neuronal repair.
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Affiliation(s)
- Farzane Sivandzade
- Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center, Amarillo, TX 79106, USA;
| | - Faleh Alqahtani
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia;
| | - Luca Cucullo
- Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center, Amarillo, TX 79106, USA;
- Center for Blood-Brain Barrier Research, Texas Tech University Health Sciences Center, Amarillo, TX 79106, USA
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13
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Di Virgilio TG, Ietswaart M, Wilson L, Donaldson DI, Hunter AM. Understanding the Consequences of Repetitive Subconcussive Head Impacts in Sport: Brain Changes and Dampened Motor Control Are Seen After Boxing Practice. Front Hum Neurosci 2019; 13:294. [PMID: 31551732 PMCID: PMC6746992 DOI: 10.3389/fnhum.2019.00294] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 08/12/2019] [Indexed: 01/24/2023] Open
Abstract
Objectives The potential effects of exposure to repetitive subconcussive head impacts through routine participation in sport are not understood. To investigate the effects of repetitive subconcussive head impacts we studied boxers following customary training (sparring) using transcranial magnetic stimulation (TMS), decomposition electromyographic (EMG) and tests of memory. Methods Twenty amateur boxers performed three 3-min sparring bouts. Parameters of brain function and motor control were assessed prior to sparring and again immediately, 1 h and 24 h post-sparring. Twenty control participants were assessed following mock-sparring. Results One hour after sparring boxers showed increased corticomotor inhibition, altered motor unit recruitment strategies, and decreased memory performance relative to controls, with values returning to baseline by the 24 h follow up. Conclusion Repetitive subconcussive head impacts associated with sparring resulted in acute and transient brain changes similar to those previously reported in soccer heading, providing convergent evidence that sport-related head impacts produce a GABAergic response. These acute changes in brain health are reminiscent of effects seen following brain injury, and suggest a potential mechanism underlying the damaging long-term effects of routine repetitive head impacts in sport.
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Affiliation(s)
- Thomas G Di Virgilio
- Physiology, Exercise and Nutrition Research Group, University of Stirling, Stirling, United Kingdom
| | - Magdalena Ietswaart
- Psychology, Faculty of Natural Sciences, University of Stirling, Stirling, United Kingdom
| | - Lindsay Wilson
- Psychology, Faculty of Natural Sciences, University of Stirling, Stirling, United Kingdom
| | - David I Donaldson
- Psychology, Faculty of Natural Sciences, University of Stirling, Stirling, United Kingdom
| | - Angus M Hunter
- Physiology, Exercise and Nutrition Research Group, University of Stirling, Stirling, United Kingdom
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14
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Ladak AA, Enam SA, Ibrahim MT. A Review of the Molecular Mechanisms of Traumatic Brain Injury. World Neurosurg 2019; 131:126-132. [PMID: 31301445 DOI: 10.1016/j.wneu.2019.07.039] [Citation(s) in RCA: 102] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Revised: 06/30/2019] [Accepted: 07/01/2019] [Indexed: 10/26/2022]
Abstract
Traumatic brain injury (TBI) refers to any insult to the brain resulting in primary (direct) and secondary (indirect) damage to the brain parenchyma. Secondary damage is often linked to the molecular mechanisms that occur post TBI and result in excitotoxicity, neuroinflammation and cytokine damage, oxidative damage, and eventual cell death as prominent mechanisms of cell damage. We present a review highlighting the relation of each of these mechanisms with TBI, their mode of damaging brain tissue, and therapeutic correlation. We also mention the long-term sequelae and their pathophysiology in relation to TBI focusing on Parkinson disease, Alzheimer disease, epilepsy, and chronic traumatic encephalopathy. Understanding of the molecular mechanisms is important in order to realize the secondary and long-term sequelae that follow primary TBI and to devise targeted therapy for quick recovery accordingly.
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Affiliation(s)
- Asma Akbar Ladak
- Medical College, Aga Khan University Hospital, Karachi, Pakistan
| | - Syed Ather Enam
- Section of Neurosurgery, Department of Surgery, Aga Khan University Hospital, Karachi, Pakistan.
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15
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Sudhakar SK, Choi TJ, Ahmed OJ. Biophysical Modeling Suggests Optimal Drug Combinations for Improving the Efficacy of GABA Agonists after Traumatic Brain Injuries. J Neurotrauma 2019; 36:1632-1645. [PMID: 30484362 PMCID: PMC6531909 DOI: 10.1089/neu.2018.6065] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Traumatic brain injuries (TBI) lead to dramatic changes in the surviving brain tissue. Altered ion concentrations, coupled with changes in the expression of membrane-spanning proteins, create a post-TBI brain state that can lead to further neuronal loss caused by secondary excitotoxicity. Several GABA receptor agonists have been tested in the search for neuroprotection immediately after an injury, with paradoxical results. These drugs not only fail to offer neuroprotection, but can also slow down functional recovery after TBI. Here, using computational modeling, we provide a biophysical hypothesis to explain these observations. We show that the accumulation of intracellular chloride ions caused by a transient upregulation of Na+-K+-2Cl- (NKCC1) co-transporters as observed following TBI, causes GABA receptor agonists to lead to excitation and depolarization block, rather than the expected hyperpolarization. The likelihood of prolonged, excitotoxic depolarization block is further exacerbated by the extremely high levels of extracellular potassium seen after TBI. Our modeling results predict that the neuroprotective efficacy of GABA receptor agonists can be substantially enhanced when they are combined with NKCC1 co-transporter inhibitors. This suggests a rational, biophysically principled method for identifying drug combinations for neuroprotection after TBI.
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Affiliation(s)
| | - Thomas J. Choi
- Department of Psychology, University of Michigan, Ann Arbor, Michigan
| | - Omar J. Ahmed
- Department of Psychology, University of Michigan, Ann Arbor, Michigan
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan
- Department of Neuroscience Graduate Program, University of Michigan, Ann Arbor, Michigan
- Department of Kresge Hearing Research Institute, University of Michigan, Ann Arbor, Michigan
- Department of Michigan Center for Integrative Research in Critical Care, University of Michigan, Ann Arbor, Michigan
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16
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Agoston DV, Kamnaksh A. Protein biomarkers of epileptogenicity after traumatic brain injury. Neurobiol Dis 2019; 123:59-68. [PMID: 30030023 PMCID: PMC6800147 DOI: 10.1016/j.nbd.2018.07.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2018] [Revised: 07/10/2018] [Accepted: 07/16/2018] [Indexed: 12/15/2022] Open
Abstract
Traumatic brain injury (TBI) is a major risk factor for acquired epilepsy. Post-traumatic epilepsy (PTE) develops over time in up to 50% of patients with severe TBI. PTE is mostly unresponsive to traditional anti-seizure treatments suggesting distinct, injury-induced pathomechanisms in the development of this condition. Moderate and severe TBIs cause significant tissue damage, bleeding, neuron and glia death, as well as axonal, vascular, and metabolic abnormalities. These changes trigger a complex biological response aimed at curtailing the physical damage and restoring homeostasis and functionality. Although a positive correlation exists between the type and severity of TBI and PTE, there is only an incomplete understanding of the time-dependent sequelae of TBI pathobiologies and their role in epileptogenesis. Determining the temporal profile of protein biomarkers in the blood (serum or plasma) and cerebrospinal fluid (CSF) can help to identify pathobiologies underlying the development of PTE, high-risk individuals, and disease modifying therapies. Here we review the pathobiological sequelae of TBI in the context of blood- and CSF-based protein biomarkers, their potential role in epileptogenesis, and discuss future directions aimed at improving the diagnosis and treatment of PTE.
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Affiliation(s)
- Denes V Agoston
- Department of Anatomy, Physiology and Genetics, Uniformed Services University, Bethesda, MD, USA.
| | - Alaa Kamnaksh
- Department of Anatomy, Physiology and Genetics, Uniformed Services University, Bethesda, MD, USA
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17
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Radecki DZ, Johnson EL, Brown AK, Meshkin NT, Perrine SA, Gow A. Corticohippocampal Dysfunction In The OBiden Mouse Model Of Primary Oligodendrogliopathy. Sci Rep 2018; 8:16116. [PMID: 30382234 PMCID: PMC6208344 DOI: 10.1038/s41598-018-34414-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 09/25/2018] [Indexed: 12/18/2022] Open
Abstract
Despite concerted efforts over decades, the etiology of multiple sclerosis (MS) remains unclear. Autoimmunity, environmental-challenges, molecular mimicry and viral hypotheses have proven equivocal because early-stage disease is typically presymptomatic. Indeed, most animal models of MS also lack defined etiologies. We have developed a novel adult-onset oligodendrogliopathy using a delineated metabolic stress etiology in myelinating cells, and our central question is, “how much of the pathobiology of MS can be recapitulated in this model?” The analyses described herein demonstrate that innate immune activation, glial scarring, cortical and hippocampal damage with accompanying electrophysiological, behavioral and memory deficits naturally emerge from disease progression. Molecular analyses reveal neurofilament changes in normal-appearing gray matter that parallel those in cortical samples from MS patients with progressive disease. Finally, axon initial segments of deep layer pyramidal neurons are perturbed in entorhinal/frontal cortex and hippocampus from OBiden mice, and computational modeling provides insight into vulnerabilities of action potential generation during demyelination and early remyelination. We integrate these findings into a working model of corticohippocampal circuit dysfunction to predict how myelin damage might eventually lead to cognitive decline.
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Affiliation(s)
- Daniel Z Radecki
- Center for Molecular Medicine and Genetics, School of Medicine, Wayne State University, Detroit, MI, 48201, USA.,Department of Comparative Biosciences, University of Wisconsin-Madison School of Veterinary Medicine, Madison, WI, 53706, USA
| | - Elizabeth L Johnson
- Institute of Gerontology, Wayne State University, Detroit, MI, 48202, USA.,Helen Wills Neuroscience Institute, University of California, Berkeley, CA, 94720, USA
| | - Ashley K Brown
- Center for Molecular Medicine and Genetics, School of Medicine, Wayne State University, Detroit, MI, 48201, USA
| | - Nicholas T Meshkin
- Center for Molecular Medicine and Genetics, School of Medicine, Wayne State University, Detroit, MI, 48201, USA.,Department of Psychiatry and Behavioral Neurosciences, School of Medicine, Wayne State University, Detroit, MI, 48201, USA
| | - Shane A Perrine
- Department of Psychiatry and Behavioral Neurosciences, School of Medicine, Wayne State University, Detroit, MI, 48201, USA
| | - Alexander Gow
- Center for Molecular Medicine and Genetics, School of Medicine, Wayne State University, Detroit, MI, 48201, USA. .,Carman and Ann Adams Department of Pediatrics, School of Medicine, Wayne State University, Detroit, MI, 48201, USA. .,Department of Neurology, School of Medicine, Wayne State University, Detroit, MI, 48201, USA.
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18
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Koenig JB, Dulla CG. Dysregulated Glucose Metabolism as a Therapeutic Target to Reduce Post-traumatic Epilepsy. Front Cell Neurosci 2018; 12:350. [PMID: 30459556 PMCID: PMC6232824 DOI: 10.3389/fncel.2018.00350] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 09/19/2018] [Indexed: 12/13/2022] Open
Abstract
Traumatic brain injury (TBI) is a significant cause of disability worldwide and can lead to post-traumatic epilepsy. Multiple molecular, cellular, and network pathologies occur following injury which may contribute to epileptogenesis. Efforts to identify mechanisms of disease progression and biomarkers which predict clinical outcomes have focused heavily on metabolic changes. Advances in imaging approaches, combined with well-established biochemical methodologies, have revealed a complex landscape of metabolic changes that occur acutely after TBI and then evolve in the days to weeks after. Based on this rich clinical and preclinical data, combined with the success of metabolic therapies like the ketogenic diet in treating epilepsy, interest has grown in determining whether manipulating metabolic activity following TBI may have therapeutic value to prevent post-traumatic epileptogenesis. Here, we focus on changes in glucose utilization and glycolytic activity in the brain following TBI and during seizures. We review relevant literature and outline potential paths forward to utilize glycolytic inhibitors as a disease-modifying therapy for post-traumatic epilepsy.
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Affiliation(s)
- Jenny B Koenig
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States
| | - Chris G Dulla
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States
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19
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Molaie AM, Maguire J. Neuroendocrine Abnormalities Following Traumatic Brain Injury: An Important Contributor to Neuropsychiatric Sequelae. Front Endocrinol (Lausanne) 2018; 9:176. [PMID: 29922224 PMCID: PMC5996920 DOI: 10.3389/fendo.2018.00176] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 04/03/2018] [Indexed: 12/19/2022] Open
Abstract
Neuropsychiatric symptoms following traumatic brain injury (TBI) are common and contribute negatively to TBI outcomes by reducing overall quality of life. The development of neurobehavioral sequelae, such as concentration deficits, depression, anxiety, fatigue, and loss of emotional well-being has historically been attributed to an ambiguous "post-concussive syndrome," considered secondary to frank structural injury and axonal damage. However, recent research suggests that neuroendocrine dysfunction, specifically hypopituitarism, plays an important role in the etiology of these symptoms. This post-head trauma hypopituitarism (PHTH) has been shown in the past two decades to be a clinically prevalent phenomenon, and given the parallels between neuropsychiatric symptoms associated with non-TBI-induced hypopituitarism and those following TBI, it is now acknowledged that PHTH is likely a substantial contributor to these impairments. The current paper seeks to provide an overview of hypothesized pathophysiological mechanisms underlying neuroendocrine abnormalities after TBI, and to emphasize the significance of this phenomenon in the development of the neurobehavioral problems frequently seen after head trauma.
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Affiliation(s)
- Amir M. Molaie
- Tufts University School of Medicine, Boston, MA, United States
| | - Jamie Maguire
- Department of Neuroscience, Sackler School of Graduate Biomedical Sciences, Boston, MA, United States
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20
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Kenzie ES, Parks EL, Bigler ED, Wright DW, Lim MM, Chesnutt JC, Hawryluk GWJ, Gordon W, Wakeland W. The Dynamics of Concussion: Mapping Pathophysiology, Persistence, and Recovery With Causal-Loop Diagramming. Front Neurol 2018; 9:203. [PMID: 29670568 PMCID: PMC5893805 DOI: 10.3389/fneur.2018.00203] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 03/14/2018] [Indexed: 12/21/2022] Open
Abstract
Despite increasing public awareness and a growing body of literature on the subject of concussion, or mild traumatic brain injury, an urgent need still exists for reliable diagnostic measures, clinical care guidelines, and effective treatments for the condition. Complexity and heterogeneity complicate research efforts and indicate the need for innovative approaches to synthesize current knowledge in order to improve clinical outcomes. Methods from the interdisciplinary field of systems science, including models of complex systems, have been increasingly applied to biomedical applications and show promise for generating insight for traumatic brain injury. The current study uses causal-loop diagramming to visualize relationships between factors influencing the pathophysiology and recovery trajectories of concussive injury, including persistence of symptoms and deficits. The primary output is a series of preliminary systems maps detailing feedback loops, intrinsic dynamics, exogenous drivers, and hubs across several scales, from micro-level cellular processes to social influences. Key system features, such as the role of specific restorative feedback processes and cross-scale connections, are examined and discussed in the context of recovery trajectories. This systems approach integrates research findings across disciplines and allows components to be considered in relation to larger system influences, which enables the identification of research gaps, supports classification efforts, and provides a framework for interdisciplinary collaboration and communication-all strides that would benefit diagnosis, prognosis, and treatment in the clinic.
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Affiliation(s)
- Erin S. Kenzie
- Systems Science Program, Portland State University, Portland, OR, United States
| | - Elle L. Parks
- Systems Science Program, Portland State University, Portland, OR, United States
| | - Erin D. Bigler
- Department of Psychology and Neuroscience Center, Brigham Young University, Provo, UT, United States
| | - David W. Wright
- Department of Emergency Medicine, Emory University School of Medicine, Atlanta, GA, United States
| | - Miranda M. Lim
- Sleep Disorders Clinic, Division of Hospital and Specialty Medicine, Research Service, VA Portland Health Care System, Portland, OR, United States
- Departments of Neurology, Medicine, and Behavioral Neuroscience, Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR, United States
| | - James C. Chesnutt
- TBI/Concussion Program, Orthopedics & Rehabilitation, Neurology and Family Medicine, Oregon Health & Science University, Portland, OR, United States
| | | | - Wayne Gordon
- Department of Rehabilitation Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Wayne Wakeland
- Systems Science Program, Portland State University, Portland, OR, United States
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21
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Sex- and age-specific modulation of brain GABA levels in a mouse model of Alzheimer's disease. Neurobiol Aging 2017; 62:168-179. [PMID: 29154037 DOI: 10.1016/j.neurobiolaging.2017.10.015] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 10/05/2017] [Accepted: 10/16/2017] [Indexed: 01/12/2023]
Abstract
Age and sex are risk factors of Alzheimer's disease (AD). Among the neurotransmitter systems, gamma-aminobutyric acid (GABA) has been implicated in AD pathogenesis but the relevance of sex-specific GABAergic dysfunction during AD progression remains unknown. In the present study, we utilized state-of-the-art high-resolution magic angle spinning nuclear magnetic resonance to systematically monitor the brain region-, age-, and sex-specific modulation of GABA levels in wild-type and Tg2576 mice with amyloid pathology. In addition, we followed the possible role of reactive astrocytes in sex-specific GABA modulation. In female Tg2576 mice, hippocampal GABA levels were significantly elevated, along with higher number of reactive astrocytes and amyloid deposition. The elevated GABA was found to be produced via the monoamine oxidase-B route from putrescine in reactive astrocytes, more substantially in female than male mice, thus suggesting a role of astrocytes in memory impairment and sex-related differences in AD. Our results paint a coherent model of memory impairment in AD and signify that dynamic changes in regional GABA may be at the root of marked sex disparities observed in AD.
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22
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Liebert AD, Chow RT, Bicknell BT, Varigos E. Neuroprotective Effects Against POCD by Photobiomodulation: Evidence from Assembly/Disassembly of the Cytoskeleton. J Exp Neurosci 2016; 10:1-19. [PMID: 26848276 PMCID: PMC4737522 DOI: 10.4137/jen.s33444] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Revised: 12/09/2015] [Accepted: 12/15/2015] [Indexed: 02/07/2023] Open
Abstract
Postoperative cognitive dysfunction (POCD) is a decline in memory following anaesthesia and surgery in elderly patients. While often reversible, it consumes medical resources, compromises patient well-being, and possibly accelerates progression into Alzheimer's disease. Anesthetics have been implicated in POCD, as has neuroinflammation, as indicated by cytokine inflammatory markers. Photobiomodulation (PBM) is an effective treatment for a number of conditions, including inflammation. PBM also has a direct effect on microtubule disassembly in neurons with the formation of small, reversible varicosities, which cause neural blockade and alleviation of pain symptoms. This mimics endogenously formed varicosities that are neuroprotective against damage, toxins, and the formation of larger, destructive varicosities and focal swellings. It is proposed that PBM may be effective as a preconditioning treatment against POCD; similar to the PBM treatment, protective and abscopal effects that have been demonstrated in experimental models of macular degeneration, neurological, and cardiac conditions.
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Affiliation(s)
| | - Roberta T. Chow
- Brain and Mind Institute, University of Sydney, Sydney, NSW, Australia
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