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So C, Zhang T, Wang Q, Qiu C, Elie DLA, Pan F. The response of retinal ganglion cells to optical defocused visual stimuli in mouse retinas. Exp Eye Res 2024; 241:109834. [PMID: 38382575 DOI: 10.1016/j.exer.2024.109834] [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: 11/08/2023] [Revised: 01/31/2024] [Accepted: 02/16/2024] [Indexed: 02/23/2024]
Abstract
Myopia and astigmatism are two primary types of refractive errors characterized by inaccurate focusing images on the retina. This study aimed to investigate the response characteristics of Retinal Ganglion Cells (RGCs), represented by alpha (α) RGCs, when exposed to focused, simulated spherically defocused images and astigmatically defocused images projected onto mouse retinas. Negative pressure was applied to stretch the soma of RGC in vitro to simulate myopia using a 7-8 μm diameter glass microelectrode, resulting in a 5% increase in the cell's diameter. A custom-made device was utilized to project spherically (equal to ±10 and ± 20 D) and astigmatically (+6.00 D) defocused images onto the retinas. As a control for a deficient intact retinal circuit, αRGCs of connexin 36 knockout (Cx36 KO) mice were used. The response of αRGCs varied significantly in terms of spikes, excitatory postsynaptic currents (EPSCs) and capacitances under stretching conditions to mimic myopia. Significant differences in the amplitudes of EPSCs were observed in the majority of αRGCs when exposed to focused and spherically defocused images in normal and mechanically simulated myopic retinas. However, this difference was not observed in αRGCs of Cx36 KO mice. αRGCs demonstrated significant differences in response between focused and astigmatically defocused images. Once again, αRGCs of Cx36 KO mice did not display differences. αRGCs have the ability to detect focused, spherically, and astigmatically defocused images and exhibit differential responses ex vivo. Gap junction subunit Cx36 may play a crucial role in transmitting visual signals associated with developing and perceiving refractive errors.
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Affiliation(s)
- Chunghim So
- School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong
| | - Ting Zhang
- Centre for Eye and Vision Research (CEVR), 17W Hong Kong Science Park, Hong Kong
| | - Qin Wang
- Centre for Eye and Vision Research (CEVR), 17W Hong Kong Science Park, Hong Kong
| | - Chunting Qiu
- School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong
| | | | - Feng Pan
- School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong; Centre for Eye and Vision Research (CEVR), 17W Hong Kong Science Park, Hong Kong; Research Centre for SHARP Vision (RCSV), The Hong Kong Polytechnic University, Hong Kong; Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, China.
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2
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Basilio AV, Zeng D, Pichay LA, Ateshian GA, Xu P, Maas SA, Morrison B. Simulating Cerebral Edema and Ischemia After Traumatic Acute Subdural Hematoma Using Triphasic Swelling Biomechanics. Ann Biomed Eng 2024:10.1007/s10439-024-03496-y. [PMID: 38532172 DOI: 10.1007/s10439-024-03496-y] [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: 11/12/2023] [Accepted: 03/14/2024] [Indexed: 03/28/2024]
Abstract
Poor outcome following traumatic acute subdural hematoma (ASDH) is associated with the severity of the primary injury and secondary injury including cerebral edema and ischemia. However, the underlying secondary injury mechanism contributing to elevated intracranial pressure (ICP) and high mortality rate remains unclear. Cerebral edema occurs in response to the exposure of the intracellular fixed charge density (FCD) after cell death, causing ICP to increase. The increased ICP from swollen tissue compresses blood vessels in adjacent tissue, restricting blood flow and leading to ischemic damage. We hypothesize that the mass occupying effect of ASDH exacerbates the ischemic injury, leading to ICP elevation, which is an indicator of high mortality rate in the clinic. Using FEBio (febio.org) and triphasic swelling biomechanics, this study modeled clinically relevant ASDHs and simulated post-traumatic brain swelling and ischemia to predict ICP. Results showed that common convexity ASDH significantly increased ICP by exacerbating ischemic injury, and surgical removal of the convexity ASDH may control ICP by preventing ischemia progression. However, in cases where the primary injury is very severe, surgical intervention alone may not effectively decrease ICP, as the contribution of the hematoma to the elevated ICP is insignificant. In addition, interhemispheric ASDH, located between the cerebral hemispheres, does not significantly exacerbate ischemia, supporting the conservative surgical management generally recommended for interhemispheric ASDH. The joint effect of the mass occupying effect of the blood clot and resulting ischemia contributes to elevated ICP which may increase mortality. Our novel approach may improve the fidelity of predicting patient outcome after motor vehicle crashes and traumatic brain injuries due to other causes.
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Affiliation(s)
- Andrew V Basilio
- Department of Biomedical Engineering, Columbia University, 351 Engineering Terrace MC 8904, 1210 Amsterdam Avenue, New York, NY, 10027, USA
| | - Delin Zeng
- Department of Biomedical Engineering, Columbia University, 351 Engineering Terrace MC 8904, 1210 Amsterdam Avenue, New York, NY, 10027, USA
| | - Leanne A Pichay
- Department of Biomedical Engineering, Columbia University, 351 Engineering Terrace MC 8904, 1210 Amsterdam Avenue, New York, NY, 10027, USA
| | - Gerard A Ateshian
- Department of Biomedical Engineering, Columbia University, 351 Engineering Terrace MC 8904, 1210 Amsterdam Avenue, New York, NY, 10027, USA
- Department of Mechanical Engineering, Columbia University, 220 S. W. Mudd Building, 500 West 120th Street, New York, NY, 10027, USA
| | - Peng Xu
- Department of Biomedical Engineering, Columbia University, 351 Engineering Terrace MC 8904, 1210 Amsterdam Avenue, New York, NY, 10027, USA
| | - Steve A Maas
- Department of Bioengineering, University of Utah, 36 S. Wasatch Drive, SMBB 3100, Salt Lake City, UT, 84112, USA
| | - Barclay Morrison
- Department of Biomedical Engineering, Columbia University, 351 Engineering Terrace MC 8904, 1210 Amsterdam Avenue, New York, NY, 10027, USA.
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3
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Adams AA, Li Y, Kim HA, Pfister BJ. Dorsal root ganglion neurons recapitulate the traumatic axonal injury of CNS neurons in response to a rapid stretch in vitro. Front Cell Neurosci 2023; 17:1111403. [PMID: 37066078 PMCID: PMC10090399 DOI: 10.3389/fncel.2023.1111403] [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: 11/29/2022] [Accepted: 02/28/2023] [Indexed: 03/31/2023] Open
Abstract
Introduction: In vitro models of traumatic brain injury (TBI) commonly use neurons isolated from the central nervous system. Limitations with primary cortical cultures, however, can pose challenges to replicating some aspects of neuronal injury associated with closed head TBI. The known mechanisms of axonal degeneration from mechanical injury in TBI are in many ways similar to degenerative disease, ischemia, and spinal cord injury. It is therefore possible that the mechanisms that result in axonal degeneration in isolated cortical axons after in vitro stretch injury are shared with injured axons from different neuronal types. Dorsal root ganglia neurons (DRGN) are another neuronal source that may overcome some current limitations including remaining healthy in culture for long periods of time, ability to be isolated from adult sources, and myelinated in vitro. Methods: The current study sought to characterize the differential responses between cortical and DRGN axons to mechanical stretch injury associated with TBI. Using an in vitro model of traumatic axonal stretch injury, cortical and DRGN neurons were injured at a moderate (40% strain) and severe stretch (60% strain) and acute alterations in axonal morphology and calcium homeostasis were measured. Results: DRGN and cortical axons immediately form undulations in response to severe injury, experience similar elongation and recovery within 20 min after the initial injury, and had a similar pattern of degeneration over the first 24 h after injury. Additionally, both types of axons experienced comparable degrees of calcium influx after both moderate and severe injury that was prevented through pre-treatment with tetrodotoxin in cortical neurons and lidocaine in DRGNs. Similar to cortical axons, stretch injury also causes calcium activated proteolysis of sodium channel in DRGN axons that is prevented by treatment with lidocaine or protease inhibitors. Discussion: These findings suggest that DRGN axons share the early response of cortical neurons to a rapid stretch injury and the associated secondary injury mechanisms. The utility of a DRGN in vitro TBI model may allow future studies to explore TBI injury progression in myelinated and adult neurons.
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Affiliation(s)
- Alexandra A. Adams
- Center for Injury Biomechanics, Materials and Medicine, Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, United States
- Department of Biological Sciences, Rutgers University Newark, Newark, NJ, United States
| | - Ying Li
- Center for Injury Biomechanics, Materials and Medicine, Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, United States
| | - Haesun A. Kim
- Department of Biological Sciences, Rutgers University Newark, Newark, NJ, United States
| | - Bryan J. Pfister
- Center for Injury Biomechanics, Materials and Medicine, Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, United States
- Department of Biological Sciences, Rutgers University Newark, Newark, NJ, United States
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Almarghalani DA, Shah ZA. Progress on siRNA-based gene therapy targeting secondary injury after intracerebral hemorrhage. Gene Ther 2023; 30:1-7. [PMID: 34754099 PMCID: PMC10927018 DOI: 10.1038/s41434-021-00304-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 10/25/2021] [Accepted: 10/27/2021] [Indexed: 12/13/2022]
Abstract
Intracerebral hemorrhage (ICH) is a life-threatening condition with a high mortality rate. For survivors, quality of life is determined by primary and secondary phases of injury. The prospects for injury repair and recovery after ICH are highly dependent on the extent of secondary injury. Currently, no effective treatments are available to prevent secondary injury or its long-term effects. One promising strategy that has recently garnered attention is gene therapy, in particular, small interfering RNAs (siRNA), which silence specific genes responsible for destructive effects after hemorrhage. Gene therapy as a potential treatment for ICH is being actively researched in animal studies. However, there are many barriers to the systemic delivery of siRNA-based therapy, as the use of naked siRNA has limitations. Recently, the Food and Drug Administration approved two siRNA-based therapies, and several are undergoing Phase 3 clinical trials. In this review, we describe the advancements in siRNA-based gene therapy for ICH and also summarize its advantages and disadvantages.
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Affiliation(s)
- Daniyah A Almarghalani
- Department of Pharmacology and Experimental Therapeutics, University of Toledo, Toledo, OH, 43614, USA
- Department of Medicinal and Biological Chemistry, College of Pharmacy and Pharmaceutical Sciences, University of Toledo, Toledo, OH, 43614, USA
| | - Zahoor A Shah
- Department of Medicinal and Biological Chemistry, College of Pharmacy and Pharmaceutical Sciences, University of Toledo, Toledo, OH, 43614, USA.
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Zou X, Wang L, Xiao L, Wang S, Zhang L. Gut microbes in cerebrovascular diseases: Gut flora imbalance, potential impact mechanisms and promising treatment strategies. Front Immunol 2022; 13:975921. [PMID: 36389714 PMCID: PMC9659965 DOI: 10.3389/fimmu.2022.975921] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 10/12/2022] [Indexed: 07/28/2023] Open
Abstract
The high morbidity, mortality, and disability rates associated with cerebrovascular disease (CeVD) pose a severe danger to human health. Gut bacteria significantly affect the onset, progression, and prognosis of CeVD. Gut microbes play a critical role in gut-brain interactions, and the gut-brain axis is essential for communication in CeVD. The reflection of changes in the gut and brain caused by gut bacteria makes it possible to investigate early warning biomarkers and potential treatment targets. We primarily discussed the following three levels of brain-gut interactions in a systematic review of the connections between gut microbiota and several cerebrovascular conditions, including ischemic stroke, intracerebral hemorrhage, intracranial aneurysm, cerebral small vessel disease, and cerebral cavernous hemangioma. First, we studied the gut microbes in conjunction with CeVD and examined alterations in the core microbiota. This enabled us to identify the focus of gut microbes and determine the focus for CeVD prevention and treatment. Second, we discussed the pathological mechanisms underlying the involvement of gut microbes in CeVD occurrence and development, including immune-mediated inflammatory responses, variations in intestinal barrier function, and reciprocal effects of microbial metabolites. Finally, based on the aforementioned proven mechanisms, we assessed the effectiveness and potential applications of the current therapies, such as dietary intervention, fecal bacterial transplantation, traditional Chinese medicine, and antibiotic therapy.
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Affiliation(s)
- Xuelun Zou
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Leiyun Wang
- Department of Pharmacy, Wuhan First Hospital, Wuhan, China
| | - Linxiao Xiao
- Department of Spine Surgery, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Sai Wang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Le Zhang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Multi-Modal Monitoring Technology for Severe Cerebrovascular Disease of Human Engineering Research Center, Changsha, Hunan, China
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6
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Srinivasan G, Brafman DA. The Emergence of Model Systems to Investigate the Link Between Traumatic Brain Injury and Alzheimer’s Disease. Front Aging Neurosci 2022; 13:813544. [PMID: 35211003 PMCID: PMC8862182 DOI: 10.3389/fnagi.2021.813544] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 12/20/2021] [Indexed: 12/12/2022] Open
Abstract
Numerous epidemiological studies have demonstrated that individuals who have sustained a traumatic brain injury (TBI) have an elevated risk for developing Alzheimer’s disease and Alzheimer’s-related dementias (AD/ADRD). Despite these connections, the underlying mechanisms by which TBI induces AD-related pathology, neuronal dysfunction, and cognitive decline have yet to be elucidated. In this review, we will discuss the various in vivo and in vitro models that are being employed to provide more definite mechanistic relationships between TBI-induced mechanical injury and AD-related phenotypes. In particular, we will highlight the strengths and weaknesses of each of these model systems as it relates to advancing the understanding of the mechanisms that lead to TBI-induced AD onset and progression as well as providing platforms to evaluate potential therapies. Finally, we will discuss how emerging methods including the use of human induced pluripotent stem cell (hiPSC)-derived cultures and genome engineering technologies can be employed to generate better models of TBI-induced AD.
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7
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Xu J, Zhao L, Liu X, Sun H, Liu X, Guo Z, Wang Y, Sun W. Aqueous humor proteomic analysis of acute angle-closure glaucoma with visual field loss. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:1611. [PMID: 34926655 PMCID: PMC8640911 DOI: 10.21037/atm-21-457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 09/03/2021] [Indexed: 11/10/2022]
Abstract
Background Acute angle-closure glaucoma (AACG) is an ophthalmic emergency that occurs over the course of hours or days and may cause irreversible blindness if not treated immediately. In most cases, optic nerve damage is the cause of visual field (VF) loss in AACG. There has been no reliable biomarker found to evaluate optic nerve damage to date. Aqueous humor (AH) proteome analysis might reveal the proteomic alterations in AACG and provide helpful clues in the search for an AH biomarker of optic nerve damage and VF loss. Methods In this study, we used the AH proteome to explore the functions of differentially expressed proteins (DEPs) during disease progression. The AH proteins from the early-stage group and late-stage group were extracted and analyzed by the data-independent acquisition (DIA) method. The DEPs functions were annotated, and parallel reaction monitoring (PRM) was used to validate the key DEPs. Results A total of 87 DEPs were found. Gene Ontology analysis showed that most DEPs were enriched in immunology, hemodynamics, and apoptosis. Ingenuity pathway analysis found that vascular endothelial growth factor (VEGF) signaling, the production of reactive oxygen species (ROS) in macrophages, and the nuclear factor erythroid 2-related factor 2 (NRF2)-mediated oxidative stress response were active pathways in the late stage of AACG. The mechanism of retinal ganglion cell (RGC) death was hypothesized on the basis of DEP functional analysis. A total of 20 DEPs were validated by using PRM, and prostaglandin-H2 D-isomerase was found to have the potential to evaluate optic nerve damage. Conclusions This study showed that AH proteomic analysis could reveal the proteomic alterations in the pathogenesis of VF loss in AACG and help to provide objective protein biomarkers to evaluate VF loss. These findings will benefit the application of the AH proteome to clinical research.
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Affiliation(s)
- Jiyu Xu
- Core Facility of Instrument, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, China
| | - Liangliang Zhao
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, China
| | - Xiang Liu
- Core Facility of Instrument, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, China.,Shanghai AB Sciex Analytical Instrument Trading Co., Ltd Beijing Branch Company, Beijing, China
| | - Haidan Sun
- Core Facility of Instrument, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, China
| | - Xiaoyan Liu
- Core Facility of Instrument, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, China
| | - Zhengguang Guo
- Core Facility of Instrument, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, China
| | - Ying Wang
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, China
| | - Wei Sun
- Core Facility of Instrument, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, China
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8
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Li J, Wu X, He Y, Wu S, Guo E, Feng Y, Yang J, Li J. PINK1 antagonize intracerebral hemorrhage by promoting mitochondrial autophagy. Ann Clin Transl Neurol 2021; 8:1951-1960. [PMID: 34453779 PMCID: PMC8528457 DOI: 10.1002/acn3.51425] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Revised: 06/07/2021] [Accepted: 06/23/2021] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Intracerebral hemorrhage (ICH) causes neurotransmitter release, oligemia, membrane depolarization, mitochondrial dysfunction, and results in the high rate of mortality and functional disability. Here, we focus on PTEN-induced kinase 1 (PINK1), a mitochondrial-targeted protein kinase, and explore its role in ICH progression. METHODS The qPCR and Western blot were performed to examine the expression of PINK1 in ICH patients and mouse model. PINK1 gain- and loss-of-function mice were used to evaluate their protective role on brain injury and behavioral disorders. Flow cytometry was carried out, mitochondrial membrane potential and reactive oxygen species production were detected to explore the distribution and neuroprotective function of PINK1. RESULTS PINK1 mRNA was upregulated, however, its protein was downregulated in ICH patients. The reduction of PINK1 was mainly happened in microglial cells in ICH model. Overexpression of PINK1 is able to rescue ICH-induced behavioral disorders. PINK1 protects ICH-induced brain injury by promoting mitochondrial autophagy in microglia. CONCLUSION PINK1 possesses a neuroprotective role and antagonizes ICH by promoting mitochondrial autophagy, which may be of value as a therapeutic target for ICH treatment.
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Affiliation(s)
- Jingchen Li
- Department of Neurosurgery, the Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
| | - Xiaoyun Wu
- Department of Geriatric, the Third Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
| | - Yanbo He
- Department of Neurosurgery, Pingxiang People's Hospital, Pingxiang County, Hebei, China
| | - Song Wu
- Department of Neurosurgery, Shenze County Hospital, Shenze County, Hebei, China
| | - Erkun Guo
- Department of Neurosurgery, the Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
| | - Yan Feng
- Department of Neurosurgery, the Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
| | - Jipeng Yang
- Department of Neurosurgery, the Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
| | - Jianliang Li
- Department of Neurosurgery, the Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
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9
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Hagan ML, Balayan V, McGee-Lawrence ME. Plasma membrane disruption (PMD) formation and repair in mechanosensitive tissues. Bone 2021; 149:115970. [PMID: 33892174 PMCID: PMC8217198 DOI: 10.1016/j.bone.2021.115970] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 03/26/2021] [Accepted: 04/17/2021] [Indexed: 01/04/2023]
Abstract
Mammalian cells employ an array of biological mechanisms to detect and respond to mechanical loading in their environment. One such mechanism is the formation of plasma membrane disruptions (PMD), which foster a molecular flux across cell membranes that promotes tissue adaptation. Repair of PMD through an orchestrated activity of molecular machinery is critical for cell survival, and the rate of PMD repair can affect downstream cellular signaling. PMD have been observed to influence the mechanical behavior of skin, alveolar, and gut epithelial cells, aortic endothelial cells, corneal keratocytes and epithelial cells, cardiac and skeletal muscle myocytes, neurons, and most recently, bone cells including osteoblasts, periodontal ligament cells, and osteocytes. PMD are therefore positioned to affect the physiological behavior of a wide range of vertebrate organ systems including skeletal and cardiac muscle, skin, eyes, the gastrointestinal tract, the vasculature, the respiratory system, and the skeleton. The purpose of this review is to describe the processes of PMD formation and repair across these mechanosensitive tissues, with a particular emphasis on comparing and contrasting repair mechanisms and downstream signaling to better understand the role of PMD in skeletal mechanobiology. The implications of PMD-related mechanisms for disease and potential therapeutic applications are also explored.
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Affiliation(s)
- Mackenzie L Hagan
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, 1460 Laney Walker Blvd., CB1101, Augusta, GA, USA
| | - Vanshika Balayan
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, 1460 Laney Walker Blvd., CB1101, Augusta, GA, USA
| | - Meghan E McGee-Lawrence
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, 1460 Laney Walker Blvd., CB1101, Augusta, GA, USA; Department of Orthopaedic Surgery, Augusta University, Augusta, GA, USA.
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10
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Bobo J, Garg A, Venkatraman P, Puthenveedu M, LeDuc PR. 3D In Vitro Neuron on a Chip for Probing Calcium Mechanostimulation. ACTA ACUST UNITED AC 2020; 4:e2000080. [PMID: 32875741 DOI: 10.1002/adbi.202000080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 08/05/2020] [Indexed: 12/13/2022]
Abstract
The evolution of tissue on a chip systems holds promise for mimicking the response of biological functionality of physiological systems. One important direction for tissue on a chip approaches are neuron-based systems that could mimic neurological responses and lessen the need for in vivo experimentation. For neural research, more attention has been devoted recently to understanding mechanics due to issues in areas such as traumatic brain injury (TBI) and pain, among others. To begin to address these areas, a 3D Nerve Integrated Tissue on a Chip (NITC) approach combined with a Mechanical Excitation Testbed (MET) System is developed to impose external mechanical stimulation toward more realistic physiological environments. PC12 cells differentiated with nerve growth factor, which were cultured in a controlled 3D scaffolds, are used. The cells are labeled in a 3D NITC system with Fluo-4-AM to examine their calcium response under mechanical stimulation synchronized with image capture. Understanding the neural responses to mechanical stimulation beyond 2D systems is very important for neurological studies and future personalized strategies. This work will have implications in a diversity of areas including tissue-on-a-chip systems, biomaterials, and neuromechanics.
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Affiliation(s)
- Justin Bobo
- Department of Mechanical Engineering, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, PA, 15213, USA
| | - Akash Garg
- Department of Mechanical Engineering, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, PA, 15213, USA
| | - Prahatha Venkatraman
- Department of Pharmacology, University of Michigan, 1150 W Medical Center Dr, Ann Arbor, MI, 48109, USA
| | - Manoj Puthenveedu
- Department of Pharmacology, University of Michigan, 1150 W Medical Center Dr, Ann Arbor, MI, 48109, USA
| | - Philip R LeDuc
- Department of Mechanical Engineering, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, PA, 15213, USA.,Department of Biological Sciences, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, PA, 15213, USA
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Nia HT, Datta M, Seano G, Zhang S, Ho WW, Roberge S, Huang P, Munn LL, Jain RK. In vivo compression and imaging in mouse brain to measure the effects of solid stress. Nat Protoc 2020; 15:2321-2340. [PMID: 32681151 DOI: 10.1038/s41596-020-0328-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2018] [Accepted: 04/06/2020] [Indexed: 02/07/2023]
Abstract
We recently developed an in vivo compression device that simulates the solid mechanical forces exerted by a growing tumor on the surrounding brain tissue and delineates the physical versus biological effects of a tumor. This device, to our knowledge the first of its kind, can recapitulate the compressive forces on the cerebellar cortex from primary (e.g., glioblastoma) and metastatic (e.g., breast cancer) tumors, as well as on the cerebellum from tumors such as medulloblastoma and ependymoma. We adapted standard transparent cranial windows normally used for intravital imaging studies in mice to include a turnable screw for controlled compression (acute or chronic) and decompression of the cerebral cortex. The device enables longitudinal imaging of the compressed brain tissue over several weeks or months as the screw is progressively extended against the brain tissue to recapitulate tumor growth-induced solid stress. The cranial window can be simply installed on the mouse skull according to previously established methods, and the screw mechanism can be readily manufactured in-house. The total time for construction and implantation of the in vivo compressive cranial window is <1 h (per mouse). This technique can also be used to study a variety of other diseases or disorders that present with abnormal solid masses in the brain, including cysts and benign growths.
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Affiliation(s)
- Hadi T Nia
- Edwin L. Steele Laboratories, Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.,Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Meenal Datta
- Edwin L. Steele Laboratories, Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Giorgio Seano
- Edwin L. Steele Laboratories, Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.,Tumor Microenvironment Laboratory, Institut Curie Research Center, Paris-Saclay University, PSL Research University, Inserm U1021, CNRS UMR3347, Orsay, France
| | - Sue Zhang
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - William W Ho
- Edwin L. Steele Laboratories, Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.,Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Sylvie Roberge
- Edwin L. Steele Laboratories, Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Peigen Huang
- Edwin L. Steele Laboratories, Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Lance L Munn
- Edwin L. Steele Laboratories, Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Rakesh K Jain
- Edwin L. Steele Laboratories, Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
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12
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Choy KW, Tsai APY, Lin PBC, Wu MY, Lee C, Alias A, Pang CY, Liew HK. The Role of Urocortins in Intracerebral Hemorrhage. Biomolecules 2020; 10:biom10010096. [PMID: 31935997 PMCID: PMC7022917 DOI: 10.3390/biom10010096] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 12/31/2019] [Accepted: 01/02/2020] [Indexed: 12/22/2022] Open
Abstract
Intracerebral hemorrhage (ICH) causes an accumulation of blood in the brain parenchyma that disrupts the normal neurological function of the brain. Despite extensive clinical trials, no medical or surgical therapy has shown to be effective in managing ICH, resulting in a poor prognosis for the patients. Urocortin (UCN) is a 40-amino-acid endogenous neuropeptide that belongs to the corticotropin-releasing hormone (CRH) family. The effect of UCN is activated by binding to two G-protein coupled receptors, CRH-R1 and CRH-R2, which are expressed in brain neurons and glial cells in various brain regions. Current research has shown that UCN exerts neuroprotective effects in ICH models via anti-inflammatory effects, which generally reduced brain edema and reduced blood-brain barrier disruption. These effects gradually help in the improvement of the neurological outcome, and thus, UCN may be a potential therapeutic target in the treatment of ICH. This review summarizes the data published to date on the role of UCN in ICH and the possible protective mechanisms underlined.
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Affiliation(s)
- Ker Woon Choy
- Department of Anatomy, Faculty of Medicine, Universiti Teknologi MARA, Sungai Buloh 42300, Malaysia;
| | - Andy Po-Yi Tsai
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (A.P.-Y.T.); (P.B.-C.L.)
| | - Peter Bor-Chian Lin
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (A.P.-Y.T.); (P.B.-C.L.)
| | - Meng-Yu Wu
- Department of Emergency Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei 231, Taiwan;
- Department of Emergency Medicine, School of Medicine, Tzu Chi University, Hualien 970, Taiwan
| | - Chihyi Lee
- College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60607, USA;
| | - Aspalilah Alias
- Department of Basic Sciences and Oral Biology, Faculty of Dentistry, Universiti Sains Islam Malaysia, Nilai 71800, Malaysia;
| | - Cheng-Yoong Pang
- Department of Medical Research, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, No. 707, Section 3, Zhong-yang Road, Hualien 970, Taiwan
- CardioVascular Research Center, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien 970, Taiwan
- Institute of Medical Sciences, Tzu Chi University, Hualien 970, Taiwan
- Correspondence: (C.-Y.P.); or (H.-K.L.); Tel.: +886-3-8561825 (ext. 15911) (H.-K.L.); Fax: +886-3-8562019 (H.-K.L.)
| | - Hock-Kean Liew
- Department of Medical Research, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, No. 707, Section 3, Zhong-yang Road, Hualien 970, Taiwan
- CardioVascular Research Center, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien 970, Taiwan
- PhD Program in Pharmacology and Toxicology, Tzu Chi University, Hualien 970, Taiwan
- Neuro-Medical Scientific Center, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien 970, Taiwan
- Correspondence: (C.-Y.P.); or (H.-K.L.); Tel.: +886-3-8561825 (ext. 15911) (H.-K.L.); Fax: +886-3-8562019 (H.-K.L.)
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13
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Direct Observation of Low Strain, High Rate Deformation of Cultured Brain Tissue During Primary Blast. Ann Biomed Eng 2019; 48:1196-1206. [DOI: 10.1007/s10439-019-02437-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 12/08/2019] [Indexed: 10/25/2022]
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14
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Hernandez ML, Chatlos T, Gorse KM, Lafrenaye AD. Neuronal Membrane Disruption Occurs Late Following Diffuse Brain Trauma in Rats and Involves a Subpopulation of NeuN Negative Cortical Neurons. Front Neurol 2019; 10:1238. [PMID: 31824411 PMCID: PMC6883004 DOI: 10.3389/fneur.2019.01238] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 11/07/2019] [Indexed: 01/20/2023] Open
Abstract
The repercussions of traumatic brain injury (TBI) endure years following the initial insult and involve chronic impairments/disabilities. Studies indicate that these morbidities stem from diffuse pathologies, however, knowledge regarding TBI-mediated diffuse pathologies, and in particular, diffuse neuronal membrane disruption, is limited. Membrane disruption has been shown to occur acutely following injury, primarily within neurons, however, the progression of TBI-induced membrane disruption remains undefined. Therefore, the current study investigated this pathology over a longer temporal profile from 6 h to 4 w following diffuse TBI induced using the central fluid percussion injury (CFPI) model in rats. To visualize membrane disruption, animals received an intracerebroventricular infusion of tagged cell-impermeable dextran 2 h prior to experimental endpoints at 6 h, 1 d, 3 d, 1 w, 2 w, or 4 w post-CFPI. The percentage of total neurons demonstrating dextran uptake, indicative of membrane disruption, was quantified within the lateral neocortex layers V and VI from 6 h to 4 w post-injury. We found that membrane disruption displayed a biphasic pattern, where nearly half of the neurons were membrane disrupted sub-acutely, from 6 h to 3 d post-TBI. At 1 w the membrane disrupted population was dramatically reduced to levels indistinguishable from sham controls. However, by 2 and 4 w following CFPI, approximately half of the neurons analyzed displayed membrane disruption. Moreover, our data revealed that a subset of these late membrane disrupted neurons were NeuN negative (NeuN-). Correlative western blot analyses, however, revealed no difference in NeuN protein expression in the lateral neocortex at any time following injury. Furthermore, the NeuN- membrane disrupted neurons did not co-label with traditional markers of astrocytes, microglia, oligodendrocytes, or NG2 cells. Immunohistochemistry against NeuN, paired with a hematoxylin and eosin counter-stain, was performed to quantify the possibility of overall NeuN+ neuronal loss following CFPI. A NeuN- population was observed consistently in both sham and injured animals regardless of time post-injury. These data suggest that there is a consistent subpopulation of NeuN- neurons within the lateral neocortex regardless of injury and that these NeuN- neurons are potentially more vulnerable to late membrane disruption. Better understanding of membrane disruption could provide insight into the mechanisms of diffuse pathology and lead to the discovery of novel treatments for TBI.
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Affiliation(s)
- Martina L. Hernandez
- Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA, United States
| | - Todd Chatlos
- Department of Neurology, University of California, Davis, Davis, CA, United States
| | - Karen M. Gorse
- Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA, United States
| | - Audrey D. Lafrenaye
- Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA, United States
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15
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Patel MV, Sewell E, Dickson S, Kim H, Meaney DF, Firestein BL. A Role for Postsynaptic Density 95 and Its Binding Partners in Models of Traumatic Brain Injury. J Neurotrauma 2019; 36:2129-2138. [DOI: 10.1089/neu.2018.6291] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Affiliation(s)
- Mihir V. Patel
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, New Jersey
- Graduate Program in Neurosciences, Rutgers University, Piscataway, New Jersey
| | - Emily Sewell
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Samantha Dickson
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Hyuck Kim
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, New Jersey
| | - David F. Meaney
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Bonnie L. Firestein
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, New Jersey
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16
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Ko J, Hemphill M, Yang Z, Sewell E, Na YJ, Sandsmark DK, Haber M, Fisher SA, Torre EA, Svane KC, Omelchenko A, Firestein BL, Diaz-Arrastia R, Kim J, Meaney DF, Issadore D. Diagnosis of traumatic brain injury using miRNA signatures in nanomagnetically isolated brain-derived extracellular vesicles. LAB ON A CHIP 2018; 18:3617-3630. [PMID: 30357245 PMCID: PMC6334845 DOI: 10.1039/c8lc00672e] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The accurate diagnosis and clinical management of traumatic brain injury (TBI) is currently limited by the lack of accessible molecular biomarkers that reflect the pathophysiology of this heterogeneous disease. To address this challenge, we developed a microchip diagnostic that can characterize TBI more comprehensively using the RNA found in brain-derived extracellular vesicles (EVs). Our approach measures a panel of EV miRNAs, processed with machine learning algorithms to capture the state of the injured and recovering brain. Our diagnostic combines surface marker-specific nanomagnetic isolation of brain-derived EVs, biomarker discovery using RNA sequencing, and machine learning processing of the EV miRNA cargo to minimally invasively measure the state of TBI. We achieved an accuracy of 99% identifying the signature of injured vs. sham control mice using an independent blinded test set (N = 77), where the injured group consists of heterogeneous populations (injury intensity, elapsed time since injury) to model the variability present in clinical samples. Moreover, we successfully predicted the intensity of the injury, the elapsed time since injury, and the presence of a prior injury using independent blinded test sets (N = 82). We demonstrated the translatability in a blinded test set by identifying TBI patients from healthy controls (AUC = 0.9, N = 60). This approach, which can detect signatures of injury that persist across a variety of injury types and individual responses to injury, more accurately reflects the heterogeneity of human TBI injury and recovery than conventional diagnostics, opening new opportunities to improve treatment of traumatic brain injuries.
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Affiliation(s)
- J Ko
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - M Hemphill
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - Z Yang
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - E Sewell
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - Y J Na
- Department of Medicine, Division of Nephrology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - D K Sandsmark
- Department of Neurology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - M Haber
- Department of Neurology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - S A Fisher
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - E A Torre
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - K C Svane
- Department of Cell Biology and Neuroscience, Rutgers, the State University of New Jersey, NJ 08854, USA
| | - A Omelchenko
- Department of Cell Biology and Neuroscience, Rutgers, the State University of New Jersey, NJ 08854, USA
| | - B L Firestein
- Department of Cell Biology and Neuroscience, Rutgers, the State University of New Jersey, NJ 08854, USA
| | - R Diaz-Arrastia
- Department of Neurology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - J Kim
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA and Department of Computer and Information Science, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - D F Meaney
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA. and Department of Neurosurgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - D Issadore
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA. and Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
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17
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Qureshi AI, Qureshi MH. Acute hypertensive response in patients with intracerebral hemorrhage pathophysiology and treatment. J Cereb Blood Flow Metab 2018; 38:1551-1563. [PMID: 28812942 PMCID: PMC6125978 DOI: 10.1177/0271678x17725431] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Acute hypertensive response is a common systemic response to occurrence of intracerebral hemorrhage which has gained unique prominence due to high prevalence and association with hematoma expansion and increased mortality. Presumably, the higher systemic blood pressure predisposes to continued intraparenchymal hemorrhage by transmission of higher pressure to the damaged small arteries and may interact with hemostatic and inflammatory pathways. Therefore, intensive reduction of systolic blood pressure has been evaluated in several clinical trials as a strategy to reduce hematoma expansion and subsequent death and disability. These trials have demonstrated either a small magnitude benefit (second intensive blood pressure reduction in acute cerebral hemorrhage trial and efficacy of nitric oxide in stroke trial) or no benefit (antihypertensive treatment of acute cerebral hemorrhage 2 trial) with intensive systolic blood pressure reduction compared with modest or standard blood pressure reduction. The differences may be explained by the variation in intensity of systolic blood pressure reduction between trials. A treatment threshold of systolic blood pressure of ≥180 mm with the target goal of systolic blood pressure reduction to values between 130 and 150 mm Hg within 6 h of symptom onset may be best supported by current evidence.
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18
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Li F, Li X, Yang J, Guo X, Zheng X, Lv Z, Shi C. Increased Expression of Apo-J and Omi/HtrA2 After Intracerebral Hemorrhage in Rats. World Neurosurg 2018; 116:e26-e34. [PMID: 29581019 DOI: 10.1016/j.wneu.2018.03.110] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 03/14/2018] [Accepted: 03/15/2018] [Indexed: 10/17/2022]
Abstract
OBJECTIVE To investigate the changes of Apo-J and Omi/HtrA2 protein expression in rats with intracerebral hemorrhage. METHODS 150 Sprague-Dawley adult rats were randomly divided into 3 groups: (1) normal control (NC) group, (2) sham group, and (3) intracerebral hemorrhage (ICH) group. The data were collected at 6 hours, 12 hours, 1 day, 2 days, 3 days, 5 days, and 7 days. Apoptosis was measured by terminal deoxynucleotidyl transferase-mediated biotinylated-dUTP nick-end labeling staining. The distributions of the Apo-J and Omi/HtrA2 proteins were determined by immunohistochemical staining. The levels of Apo-J mRNA and Omi/HtrA2 mRNA expressions were examined by real-time polymerase chain reaction. RESULTS Apoptosis in the ICH group was higher than in the sham and NC groups (P < 0.05). Both the Apo-J and Omi/HtrA2 expression levels were increased in the peripheral region of hemorrhage, with a peak at 3 days. The Apo-J mRNA level positively correlated with the HtrA2 mRNA level in the ICH group (r = 0.883, P < 0.001). CONCLUSION The expressions of Apo-J and Omi/HtrA2 increased in parallel in the peripheral region of rat cerebral hemorrhage. Local high expression of Apo-J in the peripheral regions may play a neuroprotective role by inhibiting apoptosis via the Omi/HtrA2 pathway after hemorrhage.
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Affiliation(s)
- Feng Li
- Department of Neurology, Wenjiang District People's Hospital, Chengdu, China
| | - Xiaogang Li
- Department of Neurology, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Jing Yang
- Department of Neurology, Wenjiang District People's Hospital, Chengdu, China
| | - Xiaoyan Guo
- Department of Neurology, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Xiaomei Zheng
- Department of Neurology, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Zhiyu Lv
- Department of Neurology, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Changqing Shi
- Department of Neurosurgery, Wenjiang District People's Hospital, Chengdu, China.
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Phillips JK, Sherman SA, Oungoulian SR, Finan JD. Method for High Speed Stretch Injury of Human Induced Pluripotent Stem Cell-derived Neurons in a 96-well Format. J Vis Exp 2018. [PMID: 29733307 PMCID: PMC6100707 DOI: 10.3791/57305] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Traumatic brain injury (TBI) is a major clinical challenge with high morbidity and mortality. Despite decades of pre-clinical research, no proven therapies for TBI have been developed. This paper presents a novel method for pre-clinical neurotrauma research intended to complement existing pre-clinical models. It introduces human pathophysiology through the use of human induced pluripotent stem cell-derived neurons (hiPSCNs). It achieves loading pulse duration similar to the loading durations of clinical closed head impact injury. It employs a 96-well format that facilitates high throughput experiments and makes efficient use of expensive cells and culture reagents. Silicone membranes are first treated to remove neurotoxic uncured polymer and then bonded to commercial 96-well plate bodies to create stretchable 96-well plates. A custom-built device is used to indent some or all of the well bottoms from beneath, inducing equibiaxial mechanical strain that mechanically injures cells in culture in the wells. The relationship between indentation depth and mechanical strain is determined empirically using high speed videography of well bottoms during indentation. Cells, including hiPSCNs, can be cultured on these silicone membranes using modified versions of conventional cell culture protocols. Fluorescent microscopic images of cell cultures are acquired and analyzed after injury in a semi-automated fashion to quantify the level of injury in each well. The model presented is optimized for hiPSCNs but could in theory be applied to other cell types.
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Affiliation(s)
- Jack K Phillips
- Department of Neurosurgery, NorthShore University HealthSystem
| | - Sydney A Sherman
- Department of Neurosurgery, NorthShore University HealthSystem; Midwestern University/Chicago College of Osteopathic Medicine
| | | | - John D Finan
- Department of Neurosurgery, NorthShore University HealthSystem;
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20
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Nakadate H, Kurtoglu E, Furukawa H, Oikawa S, Aomura S, Kakuta A, Matsui Y. Strain-Rate Dependency of Axonal Tolerance for Uniaxial Stretching. STAPP CAR CRASH JOURNAL 2017; 61:53-65. [PMID: 29394435 DOI: 10.4271/2017-22-0003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
This study aims to clarify the relation between axonal deformation and the onset of axonal injury. Firstly, to examine the influence of strain rate on the threshold for axonal injury, cultured neurons were subjected to 12 types of stretching (strains were 0.10, 0.15, and 0.20 and strain rates were 10, 30, 50, and 70 s-1). The formation of axonal swellings and bulbs increased significantly at strain rates of 50 and 30 s-1 with strains of 0.15 and 0.20, respectively, even though those formations did not depend on strain rates in cultures exposed to a strain of 0.10. Then, to examine the influence of the strain along an axon on axonal injury, swellings were measured at every axonal angle in the stretching direction. The axons that were parallel to stretching direction were injured the most. Finally, we proposed an experimental model that subjected an axon to more accurate strain. This model observed the process of axonal injury formation by detecting the same neuron before and after stretching. These results suggest that the strain-rate dependency of axonal tolerance is induced by a higher magnitude of loading strain and an experiment focusing on axonal strain is required for obtaining more detailed injury criteria for an axon.
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Affiliation(s)
| | - Evrim Kurtoglu
- Graduate School of System Design, Tokyo Metropolitan University
| | | | - Shoko Oikawa
- Graduate School of System Design, Tokyo Metropolitan University
| | - Shigeru Aomura
- Graduate School of System Design, Tokyo Metropolitan University
| | - Akira Kakuta
- Advanced Course of Mechanical and Computer Systems Engineering, National Institute of Technology, Tokyo College
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21
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Kim DG, Kim YJ, Shin SD, Song KJ, Lee EJ, Lee YJ, Hong KJ, Park JO, Ro YS, Park YM. Effect of emergency medical service use on time interval from symptom onset to hospital admission for definitive care among patients with intracerebral hemorrhage: a multicenter observational study. Clin Exp Emerg Med 2017; 4:168-177. [PMID: 29026891 PMCID: PMC5635452 DOI: 10.15441/ceem.16.147] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 08/06/2017] [Accepted: 09/04/2017] [Indexed: 02/06/2023] Open
Abstract
Objective This study evaluated whether emergency medical service (EMS) use was associated with early arrival and admission for definitive care among intracerebral hemorrhage (ICH) patients. Methods Patients with ICH were enrolled from 29 hospitals between November 2007 and December 2012, excluding those patients with subarachnoid hemorrhage, traumatic ICH, and missing information. The patients were divided into four groups based on visit type to the definitive hospital emergency department (ED): direct visit by EMS (EMS-direct), direct visit without EMS (non-EMS-direct), transferred from a primary hospital by EMS (EMS-transfer), and transferred from a primary hospital without EMS (non-EMS-transfer). The outcomes were the proportions of participants within early (<1 hr) definitive hospital ED arrival from symptom onset (pS2ED) and those within early (<4 hr) admission from symptom onset (pS2AD). Adjusted odds ratios were calculated to determine the association between EMS use and outcomes with and without inter-hospital transfer. Results A total of 6,564 patients were enrolled. The adjusted odds ratios (95% confidence intervals) for pS2ED were 22.95 (17.73–29.72), 1.11 (0.67–1.84), and 7.95 (6.04–10.46) and those for pS2AD were 5.56 (4.70–6.56), 0.96 (0.71–1.30), and 2.35 (1.94–2.84) for the EMS-direct, EMS-transfer, and non-EMS-direct groups compared with the non-EMS-transfer group, respectively. Through the interaction model, EMS use was significantly associated with early arrival and admission among direct visiting patients but not with transferred patients. Conclusion EMS use was significantly associated with shorter time intervals from symptom onset to arrival and admission at a definitive care hospital. However, the effect disappeared when patients were transferred from a primary hospital.
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Affiliation(s)
- Dae Gon Kim
- Department of Emergency Medicine, Seoul National University Hospital, Seoul, Korea
| | - Yu Jin Kim
- Department of Emergency Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Sang Do Shin
- Department of Emergency Medicine, Seoul National University Hospital, Seoul, Korea
| | - Kyoung Jun Song
- Department of Emergency Medicine, Seoul National University Hospital, Seoul, Korea
| | - Eui Jung Lee
- Department of Emergency Medicine, Seoul National University Hospital, Seoul, Korea
| | - Yu Jin Lee
- Department of Emergency Medicine, Seoul National University Hospital, Seoul, Korea
| | - Ki Jeong Hong
- Department of Emergency Medicine, Seoul National University Boramae Medical Center, Seoul, Korea
| | - Ju Ok Park
- Department of Emergency Medicine, Seoul National University Hospital, Seoul, Korea
| | - Young Sun Ro
- Department of Emergency Medicine, Seoul National University Hospital, Seoul, Korea
| | - Yoo Mi Park
- Hallym University Graduate School of Public Health, Chuncheon, Korea
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22
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An SJ, Kim TJ, Yoon BW. Epidemiology, Risk Factors, and Clinical Features of Intracerebral Hemorrhage: An Update. J Stroke 2017; 19:3-10. [PMID: 28178408 PMCID: PMC5307940 DOI: 10.5853/jos.2016.00864] [Citation(s) in RCA: 497] [Impact Index Per Article: 71.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2016] [Revised: 12/18/2016] [Accepted: 01/06/2017] [Indexed: 12/15/2022] Open
Abstract
Intracerebral hemorrhage (ICH) is the second most common subtype of stroke and a critical disease usually leading to severe disability or death. ICH is more common in Asians, advanced age, male sex, and low- and middle-income countries. The case fatality rate of ICH is high (40% at 1 month and 54% at 1 year), and only 12% to 39% of survivors can achieve long-term functional independence. Risk factors of ICH are hypertension, current smoking, excessive alcohol consumption, hypocholesterolemia, and drugs. Old age, male sex, Asian ethnicity, chronic kidney disease, cerebral amyloid angiopathy (CAA), and cerebral microbleeds (CMBs) increase the risk of ICH. Clinical presentation varies according to the size and location of hematoma, and intraventricular extension of hemorrhage. Patients with CAA-related ICH frequently have concomitant cognitive impairment. Anticoagulation related ICH is increasing recently as the elderly population who have atrial fibrillation is increasing. As non-vitamin K antagonist oral anticoagulants (NOACs) are currently replacing warfarin, management of NOAC-associated ICH has become an emerging issue.
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Affiliation(s)
- Sang Joon An
- Department of Neurology, Seoul National University Hospital, Seoul, Korea
| | - Tae Jung Kim
- Department of Neurology, Seoul National University Hospital, Seoul, Korea
| | - Byung-Woo Yoon
- Department of Neurology, Seoul National University Hospital, Seoul, Korea
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23
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KURTOGLU E, NAKADATE H, KIKUTA K, AOMURA S, KAKUTA A. Uniaxial stretch-induced axonal injury thresholds for axonal dysfunction and disruption and strain rate effects on thresholds for mouse neuronal stem cells. ACTA ACUST UNITED AC 2017. [DOI: 10.1299/jbse.16-00598] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Evrim KURTOGLU
- Graduate School of System Design, Tokyo Metropolitan University
| | | | - Kazuhiro KIKUTA
- Graduate School of System Design, Tokyo Metropolitan University
| | - Shigeru AOMURA
- Graduate School of System Design, Tokyo Metropolitan University
| | - Akira KAKUTA
- Advanced Course of Mechanical and Computer Systems Engineering, Tokyo National College of Technology
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Kim TY, Niimi K, Takahashi E. Analysis of the protective effects of the α 2 /δ subunit of voltage-gated Ca 2+ channels in brain injury. Brain Res 2017; 1655:138-144. [DOI: 10.1016/j.brainres.2016.11.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 10/13/2016] [Accepted: 11/07/2016] [Indexed: 12/17/2022]
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25
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Bioorthogonal chemical imaging of metabolic activities in live mammalian hippocampal tissues with stimulated Raman scattering. Sci Rep 2016; 6:39660. [PMID: 28000773 PMCID: PMC5175176 DOI: 10.1038/srep39660] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 11/25/2016] [Indexed: 12/22/2022] Open
Abstract
Brain is an immensely complex system displaying dynamic and heterogeneous metabolic activities. Visualizing cellular metabolism of nucleic acids, proteins, and lipids in brain with chemical specificity has been a long-standing challenge. Recent development in metabolic labeling of small biomolecules allows the study of these metabolisms at the global level. However, these techniques generally require nonphysiological sample preparation for either destructive mass spectrometry imaging or secondary labeling with relatively bulky fluorescent labels. In this study, we have demonstrated bioorthogonal chemical imaging of DNA, RNA, protein and lipid metabolism in live rat brain hippocampal tissues by coupling stimulated Raman scattering microscopy with integrated deuterium and alkyne labeling. Heterogeneous metabolic incorporations for different molecular species and neurogenesis with newly-incorporated DNA were observed in the dentate gyrus of hippocampus at the single cell level. We further applied this platform to study metabolic responses to traumatic brain injury in hippocampal slice cultures, and observed marked upregulation of protein and lipid metabolism particularly in the hilus region of the hippocampus within days of mechanical injury. Thus, our method paves the way for the study of complex metabolic profiles in live brain tissue under both physiological and pathological conditions with single-cell resolution and minimal perturbation.
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26
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Stretch Injury of Human Induced Pluripotent Stem Cell Derived Neurons in a 96 Well Format. Sci Rep 2016; 6:34097. [PMID: 27671211 PMCID: PMC5037451 DOI: 10.1038/srep34097] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 09/07/2016] [Indexed: 01/27/2023] Open
Abstract
Traumatic brain injury (TBI) is a major cause of mortality and morbidity with limited therapeutic options. Traumatic axonal injury (TAI) is an important component of TBI pathology. It is difficult to reproduce TAI in animal models of closed head injury, but in vitro stretch injury models reproduce clinical TAI pathology. Existing in vitro models employ primary rodent neurons or human cancer cell line cells in low throughput formats. This in vitro neuronal stretch injury model employs human induced pluripotent stem cell-derived neurons (hiPSCNs) in a 96 well format. Silicone membranes were attached to 96 well plate tops to create stretchable, culture substrates. A custom-built device was designed and validated to apply repeatable, biofidelic strains and strain rates to these plates. A high content approach was used to measure injury in a hypothesis-free manner. These measurements are shown to provide a sensitive, dose-dependent, multi-modal description of the response to mechanical insult. hiPSCNs transition from healthy to injured phenotype at approximately 35% Lagrangian strain. Continued development of this model may create novel opportunities for drug discovery and exploration of the role of human genotype in TAI pathology.
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Ko J, Hemphill MA, Gabrieli D, Wu L, Yelleswarapu V, Lawrence G, Pennycooke W, Singh A, Meaney DF, Issadore D. Smartphone-enabled optofluidic exosome diagnostic for concussion recovery. Sci Rep 2016; 6:31215. [PMID: 27498963 PMCID: PMC4976377 DOI: 10.1038/srep31215] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 07/15/2016] [Indexed: 01/23/2023] Open
Abstract
A major impediment to improving the treatment of concussion is our current inability to identify patients that will experience persistent problems after the injury. Recently, brain-derived exosomes, which cross the blood-brain barrier and circulate following injury, have shown great potential as a noninvasive biomarker of brain recovery. However, clinical use of exosomes has been constrained by their small size (30–100 nm) and the extensive sample preparation (>24 hr) needed for traditional exosome measurements. To address these challenges, we developed a smartphone-enabled optofluidic platform to measure brain-derived exosomes. Sample-to-answer on our chip is 1 hour, 10x faster than conventional techniques. The key innovation is an optofluidic device that can detect enzyme amplified exosome biomarkers, and is read out using a smartphone camera. Using this approach, we detected and profiled GluR2+ exosomes in the post-injury state using both in vitro and murine models of concussion.
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Affiliation(s)
- Jina Ko
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States
| | - Matthew A Hemphill
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States
| | - David Gabrieli
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States
| | - Leon Wu
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States
| | - Venkata Yelleswarapu
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States
| | - Gladys Lawrence
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States
| | - Wesley Pennycooke
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States
| | - Anup Singh
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States
| | - Dave F Meaney
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States.,Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - David Issadore
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States.,Department of Electrical and Systems Engineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States
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Strain and rate-dependent neuronal injury in a 3D in vitro compression model of traumatic brain injury. Sci Rep 2016; 6:30550. [PMID: 27480807 PMCID: PMC4969749 DOI: 10.1038/srep30550] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 07/06/2016] [Indexed: 12/11/2022] Open
Abstract
In the United States over 1.7 million cases of traumatic brain injury are reported yearly, but predictive correlation of cellular injury to impact tissue strain is still lacking, particularly for neuronal injury resulting from compression. Given the prevalence of compressive deformations in most blunt head trauma, this information is critically important for the development of future mitigation and diagnosis strategies. Using a 3D in vitro neuronal compression model, we investigated the role of impact strain and strain rate on neuronal lifetime, viability, and pathomorphology. We find that strain magnitude and rate have profound, yet distinctively different effects on the injury pathology. While strain magnitude affects the time of neuronal death, strain rate influences the pathomorphology and extent of population injury. Cellular injury is not initiated through localized deformation of the cytoskeleton but rather driven by excess strain on the entire cell. Furthermore we find that, mechanoporation, one of the key pathological trigger mechanisms in stretch and shear neuronal injuries, was not observed under compression.
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Sun N, Keep RF, Hua Y, Xi G. Critical Role of the Sphingolipid Pathway in Stroke: a Review of Current Utility and Potential Therapeutic Targets. Transl Stroke Res 2016; 7:420-38. [PMID: 27339463 DOI: 10.1007/s12975-016-0477-3] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 06/12/2016] [Accepted: 06/15/2016] [Indexed: 12/16/2022]
Abstract
Sphingolipids are a series of cell membrane-derived lipids which act as signaling molecules and play a critical role in cell death and survival, proliferation, recognition, and migration. Sphingosine-1-phosphate acts as a key signaling molecule and regulates lymphocyte trafficking, glial cell activation, vasoconstriction, endothelial barrier function, and neuronal death pathways which plays a critical role in numerous neurological conditions. Stroke is a second leading cause of death all over the world and effective therapies are still in great demand, including ischemic stroke and hemorrhagic stroke as well as poststroke repair. Significantly, sphingolipid activities change after stroke and correlate with stroke outcome, which has promoted efforts to testify whether the sphingolipid pathway could be a novel therapeutic target in stroke. The sphingolipid metabolic pathway, the connection between the pathway and stroke, as well as therapeutic interventions to manipulate the pathway to reduce stroke-induced brain injury are discussed in this review.
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Affiliation(s)
- Na Sun
- Department of Neurosurgery, University of Michigan, 5018 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109-2200, USA
- Department of Neurology, Tianjin Medical University General Hospital, Tianjin, China
| | - Richard F Keep
- Department of Neurosurgery, University of Michigan, 5018 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109-2200, USA
| | - Ya Hua
- Department of Neurosurgery, University of Michigan, 5018 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109-2200, USA
| | - Guohua Xi
- Department of Neurosurgery, University of Michigan, 5018 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109-2200, USA.
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Abstract
Approaches for the effective management of acute stroke are sparse, and many measures for brain protection fail. However, our ability to modulate the immune system and modify the progression of multiple sclerosis is increasing. As a result, immune interventions are currently being explored as therapeutic interventions in acute stroke. In this Review, we compare the immunological features of acute stroke with those of multiple sclerosis, identify unique immunological features of stroke, and consider the evidence for immune interventions. In patients with acute stroke, microglial activation and cell death products trigger an inflammatory cascade that damages vessels and the parenchyma within minutes to hours of the ischaemia or haemorrhage. Immune interventions that restrict brain inflammation, vascular permeability and tissue oedema must be administered rapidly to reduce acute immune-mediated destruction and to avoid subsequent immunosuppression. Preliminary results suggest that the use of drugs that modify disease in multiple sclerosis might accomplish these goals in ischaemic and haemorrhagic stroke. Further elucidation of the immune mechanisms involved in stroke is likely to lead to successful immune interventions.
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Affiliation(s)
- Ying Fu
- Departments of Neurology and Immunology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China (Y.F., Q.L., F.-D.S.); Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, 525 East 68th Street, PO Box 117, New York, NY 10065, USA. (J.A.)
| | - Qiang Liu
- Departments of Neurology and Immunology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China (Y.F., Q.L., F.-D.S.); Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, 525 East 68th Street, PO Box 117, New York, NY 10065, USA. (J.A.)
| | - Josef Anrather
- Departments of Neurology and Immunology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China (Y.F., Q.L., F.-D.S.); Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, 525 East 68th Street, PO Box 117, New York, NY 10065, USA. (J.A.)
| | - Fu-Dong Shi
- Departments of Neurology and Immunology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China (Y.F., Q.L., F.-D.S.); Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, 525 East 68th Street, PO Box 117, New York, NY 10065, USA. (J.A.)
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31
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Previtera ML, Firestein BL. Glutamate affects dendritic morphology of neurons grown on compliant substrates. Biotechnol Prog 2015; 31:1128-32. [PMID: 25827105 DOI: 10.1002/btpr.2085] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 03/25/2015] [Indexed: 12/26/2022]
Abstract
Brain stiffness changes in response to injury or disease. As a secondary consequence, glutamate is released from neurons and astroglia. Two types of glutamate receptors, N-methyl-d-aspartate (NMDA) and α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, sense mechanotransduction, leading to downstream signaling in neurons. Recently, our group reported that these two receptors affect dendrite morphology in hippocampal neurons grown on compliant substrates. Blocking receptor activity has distinct effects on dendrites, depending on whether neurons are grown on soft or stiff gels. In the current study, we examine whether exposure to glutamate itself alters stiffness-mediated changes to dendrites in hippocampal neurons. We find that glutamate augments changes seen when neurons are grown on soft gels of 300 or 600 Pa, but in contrast, glutamate attenuates changes seen when neurons are grown on stiff gels of 3,000 Pa. These results suggest that there is interplay between mechanosensing and glutamate receptor activation in determining dendrite morphology in neurons.
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Affiliation(s)
- Michelle L Previtera
- Graduate Program in Molecular Biosciences, the State University of New Jersey, Piscataway, NJ, 08854-8082.,Dept. of Cell Biology and Neuroscience, the State University of New Jersey, Piscataway, NJ, 08854-8082
| | - Bonnie L Firestein
- Dept. of Cell Biology and Neuroscience, the State University of New Jersey, Piscataway, NJ, 08854-8082.,Dept. of Biomedical Engineering, Rutgers, the State University of New Jersey, Piscataway, NJ, 08854-8082
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Abstract
With a growing interest in how the brain responds and remodels itself following a traumatic injury, this chapter outlines the major organizing principles of how to study these injuries in the laboratory and extend these findings back into the clinic. A new repertoire of models is available to examine the response of isolated circuits of the brain in vitro, and to study precisely how mechanical forces applied to even small regions of these circuits can disrupt the entire circuit dysfunction. We review the existing knowledge garnered from these models and our current understanding of mechanically sensitive receptors and channels activated immediately following trauma. In turn, we point to the emergence of in silico models of network function that will lead to an improved understanding of the principles for the remodeling of circuit structure after traumatic, possibly pointing out new biological rules for circuit reassembly that would help guide new therapies for reconstructing brain circuits after trauma.
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Affiliation(s)
- David F Meaney
- Departments of Bioengineering and Neurosurgery, University of Pennsylvania, Philadelphia, PA, USA.
| | - Douglas H Smith
- Departments of Bioengineering and Neurosurgery, University of Pennsylvania, Philadelphia, PA, USA
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Moderately elevated intracranial pressure after diffuse traumatic brain injury is associated with exacerbated neuronal pathology and behavioral morbidity in the rat. J Cereb Blood Flow Metab 2014; 34:1628-36. [PMID: 25027309 PMCID: PMC4269720 DOI: 10.1038/jcbfm.2014.122] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Revised: 06/16/2014] [Accepted: 06/17/2014] [Indexed: 11/08/2022]
Abstract
Traumatic brain injury (TBI)-induced elevated intracranial pressure (ICP) is correlated with ensuing morbidity/mortality in humans. This relationship is assumed to rely mostly on the recognition that extremely elevated ICP either indicates hematoma/contusions capable of precipitating herniation or alters cerebral perfusion pressure (CPP), which precipitates global ischemia. However, whether subischemic levels of elevated ICP without hematoma/contusion contribute to increased morbidity/mortality remains unknown. To address this knowledge gap, we utilized a model of moderate diffuse TBI in rats followed by either intraventricular ICP monitoring or manual ICP elevation to 20 mm Hg, in which CPP was above ischemic levels. The effects of ICP elevation after TBI on acute and chronic histopathology, as well as on behavioral morbidity, were evaluated. ICP elevation after TBI resulted in increased acute neuronal membrane perturbation and was also associated with reduced neuronal density at 4 weeks after injury. Somatosensory hypersensitivity was exacerbated by ICP elevation and was correlated to the observed neuronal loss. In conclusion, this study indicates that morbidity and increased neuronal damage/death associated with elevated ICP can occur without concurrent global ischemia. Therefore, understanding the pathologies associated with subischemic levels of elevated ICP could lead to the development of better therapeutic strategies for the treatment and management of TBI patients.
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Single-neuron NMDA receptor phenotype influences neuronal rewiring and reintegration following traumatic injury. J Neurosci 2014; 34:4200-13. [PMID: 24647941 DOI: 10.1523/jneurosci.4172-13.2014] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Alterations in the activity of neural circuits are a common consequence of traumatic brain injury (TBI), but the relationship between single-neuron properties and the aggregate network behavior is not well understood. We recently reported that the GluN2B-containing NMDA receptors (NMDARs) are key in mediating mechanical forces during TBI, and that TBI produces a complex change in the functional connectivity of neuronal networks. Here, we evaluated whether cell-to-cell heterogeneity in the connectivity and aggregate contribution of GluN2B receptors to [Ca(2+)]i before injury influenced the functional rewiring, spontaneous activity, and network plasticity following injury using primary rat cortical dissociated neurons. We found that the functional connectivity of a neuron to its neighbors, combined with the relative influx of calcium through distinct NMDAR subtypes, together contributed to the individual neuronal response to trauma. Specifically, individual neurons whose [Ca(2+)]i oscillations were largely due to GluN2B NMDAR activation lost many of their functional targets 1 h following injury. In comparison, neurons with large GluN2A contribution or neurons with high functional connectivity both independently protected against injury-induced loss in connectivity. Mechanistically, we found that traumatic injury resulted in increased uncorrelated network activity, an effect linked to reduction of the voltage-sensitive Mg(2+) block of GluN2B-containing NMDARs. This uncorrelated activation of GluN2B subtypes after injury significantly limited the potential for network remodeling in response to a plasticity stimulus. Together, our data suggest that two single-cell characteristics, the aggregate contribution of NMDAR subtypes and the number of functional connections, influence network structure following traumatic injury.
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35
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Neuberger EJ, Wahab RA, Jayakumar A, Pfister BJ, Santhakumar V. Distinct effect of impact rise times on immediate and early neuropathology after brain injury in juvenile rats. J Neurosci Res 2014; 92:1350-1361. [PMID: 24799156 DOI: 10.1002/jnr.23401] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 03/25/2014] [Accepted: 03/28/2014] [Indexed: 12/31/2022]
Abstract
Traumatic brain injury (TBI) can occur from physical trauma from a wide spectrum of insults ranging from explosions to falls. The biomechanics of the trauma can vary in key features, including the rate and magnitude of the insult. Although the effect of peak injury pressure on neurological outcome has been examined in the fluid percussion injury (FPI) model, it is unknown whether differences in rate of rise of the injury waveform modify cellular and physiological changes after TBI. Using a programmable FPI device, we examined juvenile rats subjected to a constant peak pressure at two rates of injury: a standard FPI rate of rise and a faster rate of rise to the same peak pressure. Immediate postinjury assessment identified fewer seizures and relatively brief loss of consciousness after fast-rise injuries than after standard-rise injuries at similar peak pressures. Compared with rats injured at standard rise, fewer silver-stained injured neuronal profiles and degenerating hilar neurons were observed 4-6 hr after fast-rise FPI. However, 1 week postinjury, both fast- and standard-rise FPI resulted in hilar cell loss and enhanced perforant path-evoked granule cell field excitability compared with sham controls. Notably, the extent of neuronal loss and increase in dentate excitability were not different between rats injured at fast and standard rates of rise to peak pressure. Our data indicate that reduced cellular damage and improved immediate neurological outcome after fast rising primary concussive injuries mask the severity of the subsequent cellular and neurophysiological pathology and may be unreliable as a predictor of prognosis.
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Affiliation(s)
- Eric J Neuberger
- Department of Neurology and Neurosciences, Rutgers New Jersey Medical School, Newark, New Jersey
| | - Radia Abdul Wahab
- Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, New Jersey
| | - Archana Jayakumar
- Department of Neurology and Neurosciences, Rutgers New Jersey Medical School, Newark, New Jersey
| | - Bryan J Pfister
- Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, New Jersey
| | - Vijayalakshmi Santhakumar
- Department of Neurology and Neurosciences, Rutgers New Jersey Medical School, Newark, New Jersey.,Department of Pharmacology and Physiology, Rutgers New Jersey Medical School, Newark, New Jersey
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36
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Jung EJ, Kim WB. The Effects of Task Oriented Circuit Exercise on Balance and Cognition in Mild Dementia Patients. ACTA ACUST UNITED AC 2014. [DOI: 10.13066/kspm.2014.9.1.83] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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37
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Meaney DF, Morrison B, Dale Bass C. The mechanics of traumatic brain injury: a review of what we know and what we need to know for reducing its societal burden. J Biomech Eng 2014; 136:021008. [PMID: 24384610 PMCID: PMC4023660 DOI: 10.1115/1.4026364] [Citation(s) in RCA: 143] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Revised: 12/20/2013] [Accepted: 12/27/2013] [Indexed: 12/25/2022]
Abstract
Traumatic brain injury (TBI) is a significant public health problem, on pace to become the third leading cause of death worldwide by 2020. Moreover, emerging evidence linking repeated mild traumatic brain injury to long-term neurodegenerative disorders points out that TBI can be both an acute disorder and a chronic disease. We are at an important transition point in our understanding of TBI, as past work has generated significant advances in better protecting us against some forms of moderate and severe TBI. However, we still lack a clear understanding of how to study milder forms of injury, such as concussion, or new forms of TBI that can occur from primary blast loading. In this review, we highlight the major advances made in understanding the biomechanical basis of TBI. We point out opportunities to generate significant new advances in our understanding of TBI biomechanics, especially as it appears across the molecular, cellular, and whole organ scale.
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Affiliation(s)
- David F. Meaney
- Departments of Bioengineeringand Neurosurgery,University of Pennsylvania,Philadelphia, PA 19104-6392e-mail:
| | - Barclay Morrison
- Department of Biomedical Engineering,Columbia University,New York, NY 10027
| | - Cameron Dale Bass
- Department of Biomedical Engineering,Duke University,Durham, NC 27708-0281
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38
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Staykov D, Köhrmann M, Unterberg A. [Management of intracerebral hemorrhage: can we still learn something?]. DER NERVENARZT 2013. [PMID: 23180056 DOI: 10.1007/s00115-012-3531-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Intracerebral hemorrhage (ICH) is the most devastating form of stroke. It affects approximately 2 million people worldwide every year and is a major cause of mortality and morbidity. Despite the focus of intensive scientific research on ICH for decades there is still no proven treatment strategy for this disease. Advances in knowledge on the underlying pathomechanisms of ICH and the clinical impact have contributed to the development of novel treatment approaches. Currently, surgical treatment, aggressive blood pressure management and intraventricular fibrinolysis in patients with additional severe intraventricular hemorrhage are being investigated in large scale phase III clinical trials.
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Affiliation(s)
- D Staykov
- Neurologische Klinik, Universitätsklinikum Erlangen, Schwabachanlage 6, 91054 Erlangen, Deutschland.
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Gurkoff G, Shahlaie K, Lyeth B, Berman R. Voltage-gated calcium channel antagonists and traumatic brain injury. Pharmaceuticals (Basel) 2013; 6:788-812. [PMID: 24276315 PMCID: PMC3816709 DOI: 10.3390/ph6070788] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Revised: 06/06/2013] [Accepted: 06/06/2013] [Indexed: 01/17/2023] Open
Abstract
Traumatic brain injury (TBI) is a leading cause of death and disability in the United States. Despite more than 30 years of research, no pharmacological agents have been identified that improve neurological function following TBI. However, several lines of research described in this review provide support for further development of voltage gated calcium channel (VGCC) antagonists as potential therapeutic agents. Following TBI, neurons and astrocytes experience a rapid and sometimes enduring increase in intracellular calcium ([Ca2+]i). These fluxes in [Ca2+]i drive not only apoptotic and necrotic cell death, but also can lead to long-term cell dysfunction in surviving cells. In a limited number of in vitro experiments, both L-type and N-type VGCC antagonists successfully reduced calcium loads as well as neuronal and astrocytic cell death following mechanical injury. In rodent models of TBI, administration of VGCC antagonists reduced cell death and improved cognitive function. It is clear that there is a critical need to find effective therapeutics and rational drug delivery strategies for the management and treatment of TBI, and we believe that further investigation of VGCC antagonists should be pursued before ruling out the possibility of successful translation to the clinic.
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Affiliation(s)
- Gene Gurkoff
- Department of Neurological Surgery, One Shields Avenue, University of California, Davis, CA 95616, USA; E-Mails: (K.S.); (B.L.); (R.B.)
- NSF Center for Biophotonics Science and Technology, Suite 2700 Stockton Blvd, Suite 1400, Sacramento, CA, 95817, USA
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-530-754-7501; Fax: +1-530-754-5125
| | - Kiarash Shahlaie
- Department of Neurological Surgery, One Shields Avenue, University of California, Davis, CA 95616, USA; E-Mails: (K.S.); (B.L.); (R.B.)
| | - Bruce Lyeth
- Department of Neurological Surgery, One Shields Avenue, University of California, Davis, CA 95616, USA; E-Mails: (K.S.); (B.L.); (R.B.)
| | - Robert Berman
- Department of Neurological Surgery, One Shields Avenue, University of California, Davis, CA 95616, USA; E-Mails: (K.S.); (B.L.); (R.B.)
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Liu Y, Wang L, Long ZY, Wu YM, Wan Q, Jiang JX, Wang ZG. Inhibiting PTEN protects hippocampal neurons against stretch injury by decreasing membrane translocation of AMPA receptor GluR2 subunit. PLoS One 2013; 8:e65431. [PMID: 23799014 PMCID: PMC3684616 DOI: 10.1371/journal.pone.0065431] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Accepted: 04/29/2013] [Indexed: 11/18/2022] Open
Abstract
The AMPA type of glutamate receptors (AMPARs)-mediated excitotoxicity is involved in the secondary neuronal death following traumatic brain injury (TBI). But the underlying cellular and molecular mechanisms remain unclear. In this study, the role of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) in GluR2-lacking AMPARs mediated neuronal death was investigated through an in vitro stretch injury model of neurons. It was indicated that both the mRNA and protein levels of PTEN were increased in cultured hippocampal neurons after stretch injury, which was associated with the decreasing expression of GluR2 subunits on the surface of neuronal membrane. Inhibition of PTEN activity by its inhibitor can promote the survival of neurons through preventing reduction of GluR2 on membrane. Moreover, the effect of inhibiting GluR2-lacking AMPARs was similar to PTEN suppression-mediated neuroprotective effect in stretch injury-induced neuronal death. Further evidence identified that the total GluR2 protein of neurons was not changed in all groups. So inhibition of PTEN or blockage of GluR2-lacking AMPARs may attenuate the death of hippocampal neurons post injury through decreasing the translocation of GluR2 subunit on the membrane effectively.
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Affiliation(s)
- Yuan Liu
- Department of Research Institute of Surgery, Daping Hospital, the Third Military Medical University, State Key Laboratory of Trauma, Burns and Combined Injury, Chongqing, China
| | - Li Wang
- Department of Research Institute of Surgery, Daping Hospital, the Third Military Medical University, State Key Laboratory of Trauma, Burns and Combined Injury, Chongqing, China
| | - Zai-yun Long
- Department of Research Institute of Surgery, Daping Hospital, the Third Military Medical University, State Key Laboratory of Trauma, Burns and Combined Injury, Chongqing, China
| | - Ya-min Wu
- Department of Research Institute of Surgery, Daping Hospital, the Third Military Medical University, State Key Laboratory of Trauma, Burns and Combined Injury, Chongqing, China
| | - Qi Wan
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada, United States of America
| | - Jian-xin Jiang
- Department of Research Institute of Surgery, Daping Hospital, the Third Military Medical University, State Key Laboratory of Trauma, Burns and Combined Injury, Chongqing, China
| | - Zheng-guo Wang
- Department of Research Institute of Surgery, Daping Hospital, the Third Military Medical University, State Key Laboratory of Trauma, Burns and Combined Injury, Chongqing, China
- * E-mail:
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41
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Increased intracranial pressure after diffuse traumatic brain injury exacerbates neuronal somatic membrane poration but not axonal injury: evidence for primary intracranial pressure-induced neuronal perturbation. J Cereb Blood Flow Metab 2012; 32:1919-32. [PMID: 22781336 PMCID: PMC3463883 DOI: 10.1038/jcbfm.2012.95] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Increased intracranial pressure (ICP) associated with traumatic brain injury (TBI) is linked to increased morbidity. Although our understanding of the pathobiology of TBI has expanded, questions remain regarding the specific neuronal somatic and axonal damaging consequences of elevated ICP, independent of its impact on cerebral perfusion pressure (CPP). To investigate this, Fischer rats were subjected to moderate TBI. Measurements of ICP revealed two distinct responses to injury. One population exhibited transient increases in ICP that returned to baseline levels acutely, while the other displayed persistent ICP elevation (>20 mm Hg). Utilizing these populations, the effect of elevated ICP on neuronal pathology associated with diffuse TBI was analyzed at 6 hours after TBI. No difference in axonal injury was observed, however, rats exhibiting persistently elevated ICP postinjury revealed a doubling of neurons with chronic membrane poration compared with rats exhibiting only transient increases in ICP. Elevated postinjury ICP was not associated with a concurrent increase in DNA damage; however, traditional histological assessments did reveal increased neuronal damage, potentially associated with redistribution of cathepsin-B from the lysosomal compartment into the cytosol. These findings indicate that persistently increased ICP, without deleterious alteration of CPP, exacerbates neuronal plasmalemmal perturbation that could precipitate persistent neuronal impairment and ultimate neuronal death.
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Brunswick AS, Hwang BY, Appelboom G, Hwang RY, Piazza MA, Connolly ES. Serum biomarkers of spontaneous intracerebral hemorrhage induced secondary brain injury. J Neurol Sci 2012; 321:1-10. [PMID: 22857988 DOI: 10.1016/j.jns.2012.06.008] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2011] [Revised: 06/13/2012] [Accepted: 06/23/2012] [Indexed: 01/01/2023]
Abstract
Intracerebral hemorrhage (ICH) is a devastating form of stroke associated with a high rate of morbidity and mortality. It is now believed that much of this damage occurs in the subacute period following the initial insult via a cascade of complex pathophysiologic pathways that continues to be investigated. Increased levels of certain serum proteins have been identified as biomarkers that may reflect or directly participate in the inflammation, blood brain barrier disruption, endothelial dysfunction, and neuronal and glial toxicity that occur during this secondary period of cerebral injury. Some of these biomarkers have the potential to serve as therapeutic targets or surrogate endpoints for future research or clinical trials. Others may someday augment current clinical techniques in diagnosis, risk-stratification, prognostication, treatment decision and measurement of therapeutic efficacy. While much work remains to be done, biomarkers show significant potential to expand clinical options and improve clinical management, thereby reducing mortality and improving functional outcomes in ICH patients.
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Affiliation(s)
- Andrew S Brunswick
- Department of Neurological Surgery, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
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43
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Mesfin MN, von Reyn CR, Mott RE, Putt ME, Meaney DF. In vitro stretch injury induces time- and severity-dependent alterations of STEP phosphorylation and proteolysis in neurons. J Neurotrauma 2012; 29:1982-98. [PMID: 22435660 DOI: 10.1089/neu.2011.2253] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Striatal-enriched tyrosine phosphatase (STEP) has been identified as a component of physiological and pathophysiological signaling pathways mediated by N-methyl-d-aspartate (NMDA) receptor/calcineurin/calpain activation. Activation of these pathways produces a subsequent change in STEP isoform expression or activation via dephosphorylation. In this study, we evaluated changes in STEP phosphorylation and proteolysis in dissociated cortical neurons after sublethal and lethal mechanical injury using an in vitro stretch injury device. Sublethal stretch injury produces minimal changes in STEP phosphorylation at early time points, and increased STEP phosphorylation at 24 h that is blocked by the NMDA-receptor antagonist APV, the calcineurin-inhibitor FK506, and the sodium channel blocker tetrodotoxin. Lethal stretch injury produces rapid STEP dephosphorylation via NR2B-containing NMDA receptors, but not calcineurin, and a subsequent biphasic phosphorylation pattern. STEP(61) expression progressively increases after sublethal stretch with no change in calpain-mediated STEP(33) formation, while lethal stretch injury results in STEP(33) formation via a NR2B-containing NMDA receptor pathway within 1 h of injury. Blocking calpain activation in the initial 30 min after stretch injury increases the ratio of active STEP in cells and blocks STEP(33) formation, suggesting that STEP is an early substrate of calpain after mechanical injury. There is a strong correlation between the amount of STEP(33) formed and the degree of cell death observed after lethal stretch injury. In summary, these data demonstrate that previously characterized pathways of STEP regulation via the NMDA receptor are generally conserved in mechanical injury, and suggest that calpain-mediated cleavage of STEP(33) should be further examined as an early marker of neuronal fate after stretch injury.
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Affiliation(s)
- Mahlet N Mesfin
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
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44
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Weber JT. Altered calcium signaling following traumatic brain injury. Front Pharmacol 2012; 3:60. [PMID: 22518104 PMCID: PMC3324969 DOI: 10.3389/fphar.2012.00060] [Citation(s) in RCA: 138] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2012] [Accepted: 03/24/2012] [Indexed: 01/10/2023] Open
Abstract
Cell death and dysfunction after traumatic brain injury (TBI) is caused by a primary phase, related to direct mechanical disruption of the brain, and a secondary phase which consists of delayed events initiated at the time of the physical insult. Arguably, the calcium ion contributes greatly to the delayed cell damage and death after TBI. A large, sustained influx of calcium into cells can initiate cell death signaling cascades, through activation of several degradative enzymes, such as proteases and endonucleases. However, a sustained level of intracellular free calcium is not necessarily lethal, but the specific route of calcium entry may couple calcium directly to cell death pathways. Other sources of calcium, such as intracellular calcium stores, can also contribute to cell damage. In addition, calcium-mediated signal transduction pathways in neurons may be perturbed following injury. These latter types of alterations may contribute to abnormal physiology in neurons that do not necessarily die after a traumatic episode. This review provides an overview of experimental evidence that has led to our current understanding of the role of calcium signaling in death and dysfunction following TBI.
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Affiliation(s)
- John T. Weber
- School of Pharmacy and Division of BioMedical Sciences, Faculty of Medicine, Memorial University of NewfoundlandSt. John’s, NL, Canada
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45
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Spaethling J, Le L, Meaney DF. NMDA receptor mediated phosphorylation of GluR1 subunits contributes to the appearance of calcium-permeable AMPA receptors after mechanical stretch injury. Neurobiol Dis 2012; 46:646-54. [PMID: 22426393 DOI: 10.1016/j.nbd.2012.03.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Revised: 01/30/2012] [Accepted: 03/01/2012] [Indexed: 10/28/2022] Open
Abstract
Alterations in neuronal cytosolic calcium is a key mediator of the traumatic brain injury (TBI) pathobiology, but less is known of the role and source of calcium in shaping early changes in synaptic receptors and neural circuits after TBI. In this study, we examined the calcium source and potential phosphorylation events leading to insertion of calcium-permeable AMPARs (CP-AMPARs) after in vitro traumatic brain injury, a receptor subtype that influences neural circuit dynamics for hours to days following injury. We found that both synaptic and NR2B-containing NMDARs contribute significantly to the calcium influx following stretch injury. Moreover, an early and sustained phosphorylation of the S-831 site of the GluR1 subunit appeared after mechanical injury, and this phosphorylation was blocked with the inhibition of either synaptic NMDARs or NR2B-containing NMDARs. In comparison, mechanical injury led to no significant change in the S-845 phosphorylation of the GluR1 subunit. Although no change in S-845 phosphorylation appeared in injured cultures, we observed that inhibition of NR2B-containing NMDARs significantly increased S-845 phosphorylation 1h after injury while blockade of synaptic NMDARs did not change S-845 phosphorylation at any time point following injury. These findings show that a broad class of NMDARs are activated in parallel and that targeting either subpopulation will reverse some of the consequences of mechanical injury, providing distinct paths to treat the effects of mechanical injury on neural circuits after TBI.
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Affiliation(s)
- Jennifer Spaethling
- Department of Pharmacology, University of Pennsylvania, Philadelphia, PA 19104, United States
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46
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Skotak M, Wang F, Chandra N. An in vitro injury model for SH-SY5Y neuroblastoma cells: effect of strain and strain rate. J Neurosci Methods 2012; 205:159-68. [PMID: 22257521 DOI: 10.1016/j.jneumeth.2012.01.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Revised: 12/29/2011] [Accepted: 01/05/2012] [Indexed: 01/18/2023]
Abstract
There is a great need to have in vitro cell injury model wherein a wide range of strain (ɛ) and strain rate (ε˙) can be precisely and independently applied. Such a model will enable exploration of various biomechanical loading conditions cells normally encounter during either blunt or blast impact-induced traumatic brain injuries (TBIs). In combination with a highly automated data acquisition and analysis system, this method can quickly generate a large data set of experimental results to yield identification of bio-mechanical and chemical sequelae following injury. A proper understanding of these sequelae will enable the discovery of the time window of opportunity available for pharmacological interventions. In this study we present such an injury model, a modified version of the Cultured Axonal Injury (CAI) device, and demonstrate its efficacy through viability of SH-SY5Y cells at different ranges of strain (0-140%) and strain rate (15-68 s⁻¹). We identified three different regimes in the stretch-induced dose-response of curves of SH-SY5Y cells, with a very sharp decline from live to dead in a narrow range of strain (30-55%). The effect of strain rate is minimal when the final strain in the cells was fixed at 50%. The model further shows that time-after-injury plays a vital role in the determination of recovery-deterioration pathways and the biological selection depends on the severity of initial injury. These data point out the initial strain level is vital to the cell fate and emphasize the need to study the various mechanisms triggered by different magnitudes of initial injuries.
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Affiliation(s)
- Maciej Skotak
- Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588-0526, USA
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47
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Patel TP, Ventre SC, Meaney DF. Dynamic changes in neural circuit topology following mild mechanical injury in vitro. Ann Biomed Eng 2011; 40:23-36. [PMID: 21994056 DOI: 10.1007/s10439-011-0390-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2011] [Accepted: 08/24/2011] [Indexed: 11/26/2022]
Abstract
Despite its enormous incidence, mild traumatic brain injury is not well understood. One aspect that needs more definition is how the mechanical energy during injury affects neural circuit function. Recent developments in cellular imaging probes provide an opportunity to assess the dynamic state of neural networks with single-cell resolution. In this article, we developed imaging methods to assess the state of dissociated cortical networks exposed to mild injury. We estimated the imaging conditions needed to achieve accurate measures of network properties, and applied these methodologies to evaluate if mild mechanical injury to cortical neurons produces graded changes to either spontaneous network activity or altered network topology. We found that modest injury produced a transient increase in calcium activity that dissipated within 1 h after injury. Alternatively, moderate mechanical injury produced immediate disruption in network synchrony, loss in excitatory tone, and increased modular topology. A calcium-activated neutral protease (calpain) was a key intermediary in these changes; blocking calpain activation restored the network nearly completely to its pre-injury state. Together, these findings show a more complex change in neural circuit behavior than previously reported for mild mechanical injury, and highlight at least one important early mechanism responsible for these changes.
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Affiliation(s)
- Tapan P Patel
- Department of Bioengineering, University of Pennsylvania, 220 S 33rd St, Philadelphia, PA 19104, USA
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48
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Magou GC, Guo Y, Choudhury M, Chen L, Hususan N, Masotti S, Pfister BJ. Engineering a high throughput axon injury system. J Neurotrauma 2011; 28:2203-18. [PMID: 21787172 DOI: 10.1089/neu.2010.1596] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Several key biological mechanisms of traumatic injury to axons have been elucidated using in vitro stretch injury models. These models, however, are based on the experimentation of single cultures keeping productivity slow. Indeed, low yield has hindered important and well-founded investigations requiring high throughput methods such as proteomic analyses. To meet this need, we engineered a multi-well high throughput injury device to accelerate and accommodate the next generation of traumatic brain injury research. This modular system stretch injures neuronal cultures in either a 24-well culture plate format or 6 individual wells simultaneously. Custom software control allows the user to accurately program the pressure pulse parameters to achieve the desired substrate deformation and injury parameters. Analysis of the pressure waveforms showed that peak pressure was linearly related to input pressure and valve open times and that the 6- and 24-well modules displayed rise times, peak pressures, and decays with extremely small standard deviations. Data also confirmed that the pressure pulse was distributed evenly throughout the pressure chambers and therefore to each injury well. Importantly, the relationship between substrate deformation and applied pressure was consistent among the multiple wells and displayed a predictable linear behavior in each module. These data confirm that this multi-well system performs as well as currently used stretch injury devices and can undertake high throughput studies that are needed across the field of neurotrauma research.
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Affiliation(s)
- George C Magou
- Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, New Jersey 07102, USA
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49
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Wostyn P, De Groot V, Audenaert K, De Deyn PP. Are intracranial pressure fluctuations important in glaucoma? Med Hypotheses 2011; 77:598-600. [PMID: 21767918 DOI: 10.1016/j.mehy.2011.06.043] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Accepted: 06/27/2011] [Indexed: 11/18/2022]
Abstract
Glaucoma is one of the leading causes of irreversible blindness. Primary open-angle glaucoma (POAG), the most common type, is a progressive optic neuropathy with characteristic structural changes in the optic nerve head and functional changes in the visual field. Mechanical and vascular theories for the pathogenesis of glaucomatous optic neuropathy have been proposed. Elevated intraocular pressure (IOP) is a strong risk factor, although a subset of POAG patients has normal IOP and is designated normal tension glaucoma (NTG). Clearly, factors other than IOP are likely to be involved in retinal ganglion cell death in glaucoma. An intriguing finding of recent studies is that intracranial pressure (ICP) is lower in patients with POAG and NTG when compared with nonglaucomatous control subjects. It has been suggested that the relationship between IOP and ICP may play a fundamental role in the development of glaucoma. A decreased ICP could result in an increased trans-lamina cribrosa pressure difference (IOP minus ICP) and lead to glaucomatous damage. In the present paper, we raise the question of whether ICP fluctuations also may be important in glaucoma. The effect of ICP fluctuation might be comparable to that of IOP fluctuation, which has been recognized as an independent risk factor for glaucoma progression.
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Affiliation(s)
- Peter Wostyn
- Department of Psychiatry, PC Sint-Amandus, Reigerlostraat 10, 8730 Beernem, Belgium.
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50
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Luo P, Fei F, Zhang L, Qu Y, Fei Z. The role of glutamate receptors in traumatic brain injury: implications for postsynaptic density in pathophysiology. Brain Res Bull 2011; 85:313-20. [PMID: 21605633 DOI: 10.1016/j.brainresbull.2011.05.004] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2010] [Revised: 04/27/2011] [Accepted: 05/08/2011] [Indexed: 11/25/2022]
Abstract
Traumatic brain injury (TBI) is the major cause of death and disability, and the incidence of TBI continues to increase rapidly. In recent years, increasing attention has been paid to an important structure at the postsynaptic membrane: the postsynaptic density (PSD). Glutamate receptors, as major components of the PSD, are highly responsive to alterations in the glutamate concentration at excitatory synapses and activate intracellular signal transduction via calcium and other second messengers following TBI. PSD scaffold proteins (PSD-95, Homer, and Shank), which anchor glutamate receptors and form a network structure, also have potential effects on these downstream signaling pathways. The changes in the function and structure of these major PSD proteins are also induced by TBI, indicating that there is a more complicated mechanism associated with PSD proteins in the pathophysiological process of TBI.
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Affiliation(s)
- Peng Luo
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, 15 Changle Xi Road, Xi'an 710032, PR China
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