1
|
Kilgore MO, Hubbard WB. Effects of Low-Level Blast on Neurovascular Health and Cerebral Blood Flow: Current Findings and Future Opportunities in Neuroimaging. Int J Mol Sci 2024; 25:642. [PMID: 38203813 PMCID: PMC10779081 DOI: 10.3390/ijms25010642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 12/20/2023] [Accepted: 12/25/2023] [Indexed: 01/12/2024] Open
Abstract
Low-level blast (LLB) exposure can lead to alterations in neurological health, cerebral vasculature, and cerebral blood flow (CBF). The development of cognitive issues and behavioral abnormalities after LLB, or subconcussive blast exposure, is insidious due to the lack of acute symptoms. One major hallmark of LLB exposure is the initiation of neurovascular damage followed by the development of neurovascular dysfunction. Preclinical studies of LLB exposure demonstrate impairment to cerebral vasculature and the blood-brain barrier (BBB) at both early and long-term stages following LLB. Neuroimaging techniques, such as arterial spin labeling (ASL) using magnetic resonance imaging (MRI), have been utilized in clinical investigations to understand brain perfusion and CBF changes in response to cumulative LLB exposure. In this review, we summarize neuroimaging techniques that can further our understanding of the underlying mechanisms of blast-related neurotrauma, specifically after LLB. Neuroimaging related to cerebrovascular function can contribute to improved diagnostic and therapeutic strategies for LLB. As these same imaging modalities can capture the effects of LLB exposure in animal models, neuroimaging can serve as a gap-bridging diagnostic tool that permits a more extensive exploration of potential relationships between blast-induced changes in CBF and neurovascular health. Future research directions are suggested, including investigating chronic LLB effects on cerebral perfusion, exploring mechanisms of dysautoregulation after LLB, and measuring cerebrovascular reactivity (CVR) in preclinical LLB models.
Collapse
Affiliation(s)
- Madison O. Kilgore
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 40536, USA;
| | - W. Brad Hubbard
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 40536, USA;
- Department of Physiology, University of Kentucky, Lexington, KY 40536, USA
- Lexington Veterans’ Affairs Healthcare System, Lexington, KY 40502, USA
| |
Collapse
|
2
|
Siedhoff HR, Chen S, Song H, Cui J, Cernak I, Cifu DX, DePalma RG, Gu Z. Perspectives on Primary Blast Injury of the Brain: Translational Insights Into Non-inertial Low-Intensity Blast Injury. Front Neurol 2022; 12:818169. [PMID: 35095749 PMCID: PMC8794583 DOI: 10.3389/fneur.2021.818169] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 12/20/2021] [Indexed: 12/18/2022] Open
Abstract
Most traumatic brain injuries (TBIs) during military deployment or training are clinically "mild" and frequently caused by non-impact blast exposures. Experimental models were developed to reproduce the biological consequences of high-intensity blasts causing moderate to severe brain injuries. However, the pathophysiological mechanisms of low-intensity blast (LIB)-induced neurological deficits have been understudied. This review provides perspectives on primary blast-induced mild TBI models and discusses translational aspects of LIB exposures as defined by standardized physical parameters including overpressure, impulse, and shock wave velocity. Our mouse LIB-exposure model, which reproduces deployment-related scenarios of open-field blast (OFB), caused neurobehavioral changes, including reduced exploratory activities, elevated anxiety-like levels, impaired nesting behavior, and compromised spatial reference learning and memory. These functional impairments associate with subcellular and ultrastructural neuropathological changes, such as myelinated axonal damage, synaptic alterations, and mitochondrial abnormalities occurring in the absence of gross- or cellular damage. Biochemically, we observed dysfunctional mitochondrial pathways that led to elevated oxidative stress, impaired fission-fusion dynamics, diminished mitophagy, decreased oxidative phosphorylation, and compensated cell respiration-relevant enzyme activity. LIB also induced increased levels of total tau, phosphorylated tau, and amyloid β peptide, suggesting initiation of signaling cascades leading to neurodegeneration. We also compare translational aspects of OFB findings to alternative blast injury models. By scoping relevant recent research findings, we provide recommendations for future preclinical studies to better reflect military-operational and clinical realities. Overall, better alignment of preclinical models with clinical observations and experience related to military injuries will facilitate development of more precise diagnosis, clinical evaluation, treatment, and rehabilitation.
Collapse
Affiliation(s)
- Heather R. Siedhoff
- Department of Pathology and Anatomical Sciences, University of Missouri School of Medicine, Columbia, MO, United States
- Harry S. Truman Memorial Veterans' Hospital Research Service, Columbia, MO, United States
| | - Shanyan Chen
- Department of Pathology and Anatomical Sciences, University of Missouri School of Medicine, Columbia, MO, United States
- Harry S. Truman Memorial Veterans' Hospital Research Service, Columbia, MO, United States
| | - Hailong Song
- Department of Pathology and Anatomical Sciences, University of Missouri School of Medicine, Columbia, MO, United States
- Harry S. Truman Memorial Veterans' Hospital Research Service, Columbia, MO, United States
| | - Jiankun Cui
- Department of Pathology and Anatomical Sciences, University of Missouri School of Medicine, Columbia, MO, United States
- Harry S. Truman Memorial Veterans' Hospital Research Service, Columbia, MO, United States
| | - Ibolja Cernak
- Department of Biomedical Sciences, Mercer University School of Medicine, Macon, GA, United States
| | - David X. Cifu
- Department of Physical Medicine and Rehabilitation, Virginia Commonwealth University School of Medicine, Richmond, VA, United States
| | - Ralph G. DePalma
- Office of Research and Development, Department of Veterans Affairs, Washington, DC, United States
- Department of Surgery, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Zezong Gu
- Department of Pathology and Anatomical Sciences, University of Missouri School of Medicine, Columbia, MO, United States
- Harry S. Truman Memorial Veterans' Hospital Research Service, Columbia, MO, United States
| |
Collapse
|
3
|
Explosive-driven double-blast exposure: molecular, histopathological, and behavioral consequences. Sci Rep 2020; 10:17446. [PMID: 33060648 PMCID: PMC7566442 DOI: 10.1038/s41598-020-74296-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 09/29/2020] [Indexed: 12/17/2022] Open
Abstract
Traumatic brain injury generated by blast may induce long-term neurological and psychiatric sequelae. We aimed to identify molecular, histopathological, and behavioral changes in rats 2 weeks after explosive-driven double-blast exposure. Rats received two 30-psi (~ 207-kPa) blasts 24 h apart or were handled identically without blast. All rats were behaviorally assessed over 2 weeks. At Day 15, rats were euthanized, and brains removed. Brains were dissected into frontal cortex, hippocampus, cerebellum, and brainstem. Western blotting was performed to measure levels of total-Tau, phosphorylated-Tau (pTau), amyloid precursor protein (APP), GFAP, Iba1, αII-spectrin, and spectrin breakdown products (SBDP). Kinases and phosphatases, correlated with tau phosphorylation were also measured. Immunohistochemistry for pTau, APP, GFAP, and Iba1 was performed. pTau protein level was greater in the hippocampus, cerebellum, and brainstem and APP protein level was greater in cerebellum of blast vs control rats (p < 0.05). GFAP, Iba1, αII-spectrin, and SBDP remained unchanged. No immunohistochemical or neurobehavioral changes were observed. The dissociation between increased pTau and APP in different regions in the absence of neurobehavioral changes 2 weeks after double blast exposure is a relevant finding, consistent with human data showing that battlefield blasts might be associated with molecular changes before signs of neurological and psychiatric disorders manifest.
Collapse
|
4
|
Harper MM, Hedberg-Buenz A, Herlein J, Abrahamson EE, Anderson MG, Kuehn MH, Kardon RH, Poolman P, Ikonomovic MD. Blast-Mediated Traumatic Brain Injury Exacerbates Retinal Damage and Amyloidosis in the APPswePSENd19e Mouse Model of Alzheimer's Disease. Invest Ophthalmol Vis Sci 2019; 60:2716-2725. [PMID: 31247112 PMCID: PMC6735799 DOI: 10.1167/iovs.18-26353] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Purpose Traumatic brain injury (TBI) is a risk factor for developing chronic neurodegenerative conditions including Alzheimer's disease (AD). The purpose of this study was to examine chronic effects of blast TBI on retinal ganglion cells (RGC), optic nerve, and brain amyloid load in a mouse model of AD amyloidosis. Methods Transgenic (TG) double-mutant APPswePSENd19e (APP/PS1) mice and nontransgenic (Non-TG) littermates were exposed to a single blast TBI (20 psi) at age 2 to 3 months. RGC cell structure and function was evaluated 2 months later (average age at endpoint = 4.5 months) using pattern electroretinogram (PERG), optical coherence tomography (OCT), and the chromatic pupil light reflex (cPLR), followed by histologic analysis of retina, optic nerve, and brain amyloid pathology. Results APP/PS1 mice exposed to blast TBI (TG-Blast) had significantly lower PERG and cPLR responses 2 months after injury compared to preblast values and compared to sham groups of APP/PS1 (TG-Sham) and nontransgenic (Non-TG-Sham) mice as well as nontransgenic blast-exposed mice (Non-TG-Blast). The TG-Blast group also had significantly thinner RGC complex and more optic nerve damage compared to all groups. No amyloid-β (Aβ) deposits were detected in retinas of APP/PS1 mice; however, increased amyloid precursor protein (APP)/Aβ-immunoreactivity was seen in TG-Blast compared to TG-Sham mice, particularly near blood vessels. TG-Blast and TG-Sham groups exhibited high variability in pathology severity, with a strong, but not statistically significant, trend for greater cerebral cortical Aβ plaque load in the TG-Blast compared to TG-Sham group. Conclusions When combined with a genetic susceptibility for developing amyloidosis of AD, blast TBI exposure leads to earlier RGC and optic nerve damage associated with modest but detectable increase in cerebral cortical Aβ pathology. These findings suggest that genetic risk factors for AD may increase the sensitivity of the retina to blast-mediated damage.
Collapse
Affiliation(s)
- Matthew M Harper
- Department of Ophthalmology and Visual Sciences, The University of Iowa, Iowa City, Iowa, United States.,The Iowa City VA Center for the Prevention and Treatment of Visual Loss, Iowa City, Iowa, United States
| | - Adam Hedberg-Buenz
- The Iowa City VA Center for the Prevention and Treatment of Visual Loss, Iowa City, Iowa, United States.,Department of Molecular Physiology and Biophysics, The University of Iowa, Iowa City, Iowa, United States
| | - Judith Herlein
- The Iowa City VA Center for the Prevention and Treatment of Visual Loss, Iowa City, Iowa, United States
| | - Eric E Abrahamson
- Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States.,Geriatric Research Education and Clinical Center, Pittsburgh VA Healthcare System, Pittsburgh, Pennsylvania, United States
| | - Michael G Anderson
- Department of Ophthalmology and Visual Sciences, The University of Iowa, Iowa City, Iowa, United States.,The Iowa City VA Center for the Prevention and Treatment of Visual Loss, Iowa City, Iowa, United States.,Department of Molecular Physiology and Biophysics, The University of Iowa, Iowa City, Iowa, United States
| | - Markus H Kuehn
- Department of Ophthalmology and Visual Sciences, The University of Iowa, Iowa City, Iowa, United States.,The Iowa City VA Center for the Prevention and Treatment of Visual Loss, Iowa City, Iowa, United States
| | - Randy H Kardon
- Department of Ophthalmology and Visual Sciences, The University of Iowa, Iowa City, Iowa, United States.,The Iowa City VA Center for the Prevention and Treatment of Visual Loss, Iowa City, Iowa, United States
| | - Pieter Poolman
- Department of Ophthalmology and Visual Sciences, The University of Iowa, Iowa City, Iowa, United States.,The Iowa City VA Center for the Prevention and Treatment of Visual Loss, Iowa City, Iowa, United States
| | - Milos D Ikonomovic
- Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States.,Geriatric Research Education and Clinical Center, Pittsburgh VA Healthcare System, Pittsburgh, Pennsylvania, United States.,Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
| |
Collapse
|
5
|
|
6
|
Song H, Cui J, Simonyi A, Johnson CE, Hubler GK, DePalma RG, Gu Z. Linking blast physics to biological outcomes in mild traumatic brain injury: Narrative review and preliminary report of an open-field blast model. Behav Brain Res 2018; 340:147-158. [DOI: 10.1016/j.bbr.2016.08.037] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 08/13/2016] [Accepted: 08/19/2016] [Indexed: 12/14/2022]
|
7
|
Abstract
Susceptibility Weighted Imaging (SWI) is an established part of the clinical neuroimaging toolbox and, since its inception, has also successfully been used in various preclinical studies. Exploiting the effect of variations of magnetic susceptibility between different tissues on the externally applied, static, homogeneous magnetic field, the method visualizes venous vasculature, hemorrhages and blood degradation products, calcifications, and tissue iron deposits. The chapter describes in vivo and ex vivo protocols for preclinical SWI in rodents.
Collapse
Affiliation(s)
- Ferdinand Schweser
- Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, NY, USA.
- Center for Biomedical Imaging, Clinical and Translational Science Institute, University at Buffalo, The State University of New York, Buffalo, NY, USA.
| | - Marilena Preda
- Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, NY, USA
- Center for Biomedical Imaging, Clinical and Translational Science Institute, University at Buffalo, The State University of New York, Buffalo, NY, USA
| | - Robert Zivadinov
- Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, NY, USA
- Center for Biomedical Imaging, Clinical and Translational Science Institute, University at Buffalo, The State University of New York, Buffalo, NY, USA
| |
Collapse
|
8
|
Gill J, Cashion A, Osier N, Arcurio L, Motamedi V, Dell KC, Carr W, Kim HS, Yun S, Walker P, Ahlers S, LoPresti M, Yarnell A. Moderate blast exposure alters gene expression and levels of amyloid precursor protein. NEUROLOGY-GENETICS 2017; 3:e186. [PMID: 28975156 PMCID: PMC5618107 DOI: 10.1212/nxg.0000000000000186] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 06/30/2017] [Indexed: 11/15/2022]
Abstract
OBJECTIVE To explore gene expression after moderate blast exposure (vs baseline) and proteomic changes after moderate- (vs low-) blast exposure. METHODS Military personnel (N = 69) donated blood for quantification of protein level, and peak pressure exposures were detected by helmet sensors before and during a blast training program (10 days total). On day 7, some participants (n = 29) sustained a moderate blast (mean peak pressure = 7.9 psi) and were matched to participants with no/low-blast exposure during the training (n = 40). PAXgene tubes were collected from one training site at baseline and day 10; RNA-sequencing day 10 expression was compared with each participant's own baseline samples to identify genes and pathways differentially expressed in moderate blast-exposed participants. Changes in amyloid precursor protein (APP) from baseline to the day of blast and following 2 days were evaluated. Symptoms were assessed using a self-reported form. RESULTS We identified 1,803 differentially expressed genes after moderate blast exposure; the most altered network was APP. Significantly reduced levels of peripheral APP were detected the day after the moderate blast exposure and the following day. Protein concentrations correlated with the magnitude of the moderate blast exposure on days 8 and 9. APP concentrations returned to baseline levels 3 days following the blast, likely due to increases in the genetic expression of APP. Onset of concentration problems and headaches occurred after moderate blast. CONCLUSIONS Moderate blast exposure results in a signature biological profile that includes acute APP reductions, followed by genetic expression increases and normalization of APP levels; these changes likely influence neuronal recovery.
Collapse
Affiliation(s)
- Jessica Gill
- Intramural Research Program, CNRM Co Director Biomarkers Core, Uniformed Services University of the Health Sciences (J.G.) and National Institute of Nursing Research (A.C., N.O., L.A., V.M., H.-S.K., S.Y.), National Institutes of Health, Bethesda; Walter Reed Army Institute of Research (K.C.D., M.L., A.Y.), Silver Spring; Army Medical Research and Materiel Command (W.C.), Fort Detrick; and Naval Medical Research Center (P.W., S.A.), Silver Spring, MD
| | - Ann Cashion
- Intramural Research Program, CNRM Co Director Biomarkers Core, Uniformed Services University of the Health Sciences (J.G.) and National Institute of Nursing Research (A.C., N.O., L.A., V.M., H.-S.K., S.Y.), National Institutes of Health, Bethesda; Walter Reed Army Institute of Research (K.C.D., M.L., A.Y.), Silver Spring; Army Medical Research and Materiel Command (W.C.), Fort Detrick; and Naval Medical Research Center (P.W., S.A.), Silver Spring, MD
| | - Nicole Osier
- Intramural Research Program, CNRM Co Director Biomarkers Core, Uniformed Services University of the Health Sciences (J.G.) and National Institute of Nursing Research (A.C., N.O., L.A., V.M., H.-S.K., S.Y.), National Institutes of Health, Bethesda; Walter Reed Army Institute of Research (K.C.D., M.L., A.Y.), Silver Spring; Army Medical Research and Materiel Command (W.C.), Fort Detrick; and Naval Medical Research Center (P.W., S.A.), Silver Spring, MD
| | - Lindsay Arcurio
- Intramural Research Program, CNRM Co Director Biomarkers Core, Uniformed Services University of the Health Sciences (J.G.) and National Institute of Nursing Research (A.C., N.O., L.A., V.M., H.-S.K., S.Y.), National Institutes of Health, Bethesda; Walter Reed Army Institute of Research (K.C.D., M.L., A.Y.), Silver Spring; Army Medical Research and Materiel Command (W.C.), Fort Detrick; and Naval Medical Research Center (P.W., S.A.), Silver Spring, MD
| | - Vida Motamedi
- Intramural Research Program, CNRM Co Director Biomarkers Core, Uniformed Services University of the Health Sciences (J.G.) and National Institute of Nursing Research (A.C., N.O., L.A., V.M., H.-S.K., S.Y.), National Institutes of Health, Bethesda; Walter Reed Army Institute of Research (K.C.D., M.L., A.Y.), Silver Spring; Army Medical Research and Materiel Command (W.C.), Fort Detrick; and Naval Medical Research Center (P.W., S.A.), Silver Spring, MD
| | - Kristine C Dell
- Intramural Research Program, CNRM Co Director Biomarkers Core, Uniformed Services University of the Health Sciences (J.G.) and National Institute of Nursing Research (A.C., N.O., L.A., V.M., H.-S.K., S.Y.), National Institutes of Health, Bethesda; Walter Reed Army Institute of Research (K.C.D., M.L., A.Y.), Silver Spring; Army Medical Research and Materiel Command (W.C.), Fort Detrick; and Naval Medical Research Center (P.W., S.A.), Silver Spring, MD
| | - Walter Carr
- Intramural Research Program, CNRM Co Director Biomarkers Core, Uniformed Services University of the Health Sciences (J.G.) and National Institute of Nursing Research (A.C., N.O., L.A., V.M., H.-S.K., S.Y.), National Institutes of Health, Bethesda; Walter Reed Army Institute of Research (K.C.D., M.L., A.Y.), Silver Spring; Army Medical Research and Materiel Command (W.C.), Fort Detrick; and Naval Medical Research Center (P.W., S.A.), Silver Spring, MD
| | - Hyung-Suk Kim
- Intramural Research Program, CNRM Co Director Biomarkers Core, Uniformed Services University of the Health Sciences (J.G.) and National Institute of Nursing Research (A.C., N.O., L.A., V.M., H.-S.K., S.Y.), National Institutes of Health, Bethesda; Walter Reed Army Institute of Research (K.C.D., M.L., A.Y.), Silver Spring; Army Medical Research and Materiel Command (W.C.), Fort Detrick; and Naval Medical Research Center (P.W., S.A.), Silver Spring, MD
| | - Sijung Yun
- Intramural Research Program, CNRM Co Director Biomarkers Core, Uniformed Services University of the Health Sciences (J.G.) and National Institute of Nursing Research (A.C., N.O., L.A., V.M., H.-S.K., S.Y.), National Institutes of Health, Bethesda; Walter Reed Army Institute of Research (K.C.D., M.L., A.Y.), Silver Spring; Army Medical Research and Materiel Command (W.C.), Fort Detrick; and Naval Medical Research Center (P.W., S.A.), Silver Spring, MD
| | - Peter Walker
- Intramural Research Program, CNRM Co Director Biomarkers Core, Uniformed Services University of the Health Sciences (J.G.) and National Institute of Nursing Research (A.C., N.O., L.A., V.M., H.-S.K., S.Y.), National Institutes of Health, Bethesda; Walter Reed Army Institute of Research (K.C.D., M.L., A.Y.), Silver Spring; Army Medical Research and Materiel Command (W.C.), Fort Detrick; and Naval Medical Research Center (P.W., S.A.), Silver Spring, MD
| | - Stephen Ahlers
- Intramural Research Program, CNRM Co Director Biomarkers Core, Uniformed Services University of the Health Sciences (J.G.) and National Institute of Nursing Research (A.C., N.O., L.A., V.M., H.-S.K., S.Y.), National Institutes of Health, Bethesda; Walter Reed Army Institute of Research (K.C.D., M.L., A.Y.), Silver Spring; Army Medical Research and Materiel Command (W.C.), Fort Detrick; and Naval Medical Research Center (P.W., S.A.), Silver Spring, MD
| | - Matthew LoPresti
- Intramural Research Program, CNRM Co Director Biomarkers Core, Uniformed Services University of the Health Sciences (J.G.) and National Institute of Nursing Research (A.C., N.O., L.A., V.M., H.-S.K., S.Y.), National Institutes of Health, Bethesda; Walter Reed Army Institute of Research (K.C.D., M.L., A.Y.), Silver Spring; Army Medical Research and Materiel Command (W.C.), Fort Detrick; and Naval Medical Research Center (P.W., S.A.), Silver Spring, MD
| | - Angela Yarnell
- Intramural Research Program, CNRM Co Director Biomarkers Core, Uniformed Services University of the Health Sciences (J.G.) and National Institute of Nursing Research (A.C., N.O., L.A., V.M., H.-S.K., S.Y.), National Institutes of Health, Bethesda; Walter Reed Army Institute of Research (K.C.D., M.L., A.Y.), Silver Spring; Army Medical Research and Materiel Command (W.C.), Fort Detrick; and Naval Medical Research Center (P.W., S.A.), Silver Spring, MD
| |
Collapse
|