1
|
You XM, Xu B, Zhou H, Qiao H, Lv X, Huang Z, Pang J, Yang L, Liu PF, Guan X, Yang HG, Wang X, Yao YF. Ultrahigh Bifunctional Photocatalytic CO 2 Reduction and H 2 Evolution by Synergistic Interaction of Heteroatomic Pt-Ru Dimerization Sites. ACS NANO 2024; 18:9403-9412. [PMID: 38488193 DOI: 10.1021/acsnano.3c10807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Diatomic-site catalysts (DASCs) inherit the excellent performance of single-atom catalysts (SACs) by utilizing two adjacent atomic metal species to achieve functional complementarity and synergistic effects that improve the carbon dioxide reduction reaction (CO2RR) and H2 evolution reaction (HER) kinetics. Herein, we report a method to further improve the catalytic efficiency of Pt by using Pt and Ru single atoms randomly anchored on a g-C3N4 surface, yielding partial Pt-Ru dimers. The synthesized catalyst exhibits extraordinary photocatalytic activity and stability in both the CO2RR and HER processes. In-depth experimentation, the pH-dependent chemical exchange saturation transfer (CEST) imaging nuclear magnetic resonance (NMR) method, and theoretical analyses reveal that the excellent performance is attributed to orbital coupling between the Pt atoms and the neighboring Ru atoms (mainly dxy and dxz), which decreases the orbital energy levels and weakens the bond strength with intermediates, resulting in improved CO2RR and HER performance. This study successfully applies the pH-dependent CEST imaging NMR method to catalytic reactions, and CO2 adsorption is directly observed using CEST 2D imaging maps. This work presents significant potential for a variety of catalytic reaction applications by systematically designing bimetallic dimers with higher activity and stability.
Collapse
Affiliation(s)
- Xiao-Meng You
- Physics Department & Shanghai Key Laboratory of Magnetic Resonance, School of Physics and Electronic Science, East China Normal University, Shanghai 200241 China
| | - Beibei Xu
- Physics Department & Shanghai Key Laboratory of Magnetic Resonance, School of Physics and Electronic Science, East China Normal University, Shanghai 200241 China
| | - Hang Zhou
- Physics Department & Shanghai Key Laboratory of Magnetic Resonance, School of Physics and Electronic Science, East China Normal University, Shanghai 200241 China
| | - Hongwei Qiao
- Physics Department & Shanghai Key Laboratory of Magnetic Resonance, School of Physics and Electronic Science, East China Normal University, Shanghai 200241 China
| | - Xingxi Lv
- Physics Department & Shanghai Key Laboratory of Magnetic Resonance, School of Physics and Electronic Science, East China Normal University, Shanghai 200241 China
| | - Zejiang Huang
- Physics Department & Shanghai Key Laboratory of Magnetic Resonance, School of Physics and Electronic Science, East China Normal University, Shanghai 200241 China
| | - Jingyi Pang
- Physics Department & Shanghai Key Laboratory of Magnetic Resonance, School of Physics and Electronic Science, East China Normal University, Shanghai 200241 China
| | - Lingyun Yang
- iHuman Institute, ShanghaiTech University, Shanghai 201210, China
| | - Peng Fei Liu
- Key Laboratory for Ultrafine Materials of Ministry of Education, Shanghai, Engineering Research Center of Hierarchical Nanomaterials, School of Materials, Science and Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Xiaohong Guan
- Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, School of Ecological and Environmental Science, East China Normal University, Shanghai 200241, China
| | - Hua Gui Yang
- Key Laboratory for Ultrafine Materials of Ministry of Education, Shanghai, Engineering Research Center of Hierarchical Nanomaterials, School of Materials, Science and Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Xuelu Wang
- Physics Department & Shanghai Key Laboratory of Magnetic Resonance, School of Physics and Electronic Science, East China Normal University, Shanghai 200241 China
| | - Ye-Feng Yao
- Physics Department & Shanghai Key Laboratory of Magnetic Resonance, School of Physics and Electronic Science, East China Normal University, Shanghai 200241 China
| |
Collapse
|
2
|
Zhuang C, Chen B, Wu S, Xu L, Zhang X, Zheng X, Chen Y, Geng Y, Guan J, Lin Y, Wilman AH, Wu R. Repurposing of the PET Probe Prototype PiB for Label and Radiation-Free CEST MRI Molecular Imaging of Amyloid. ACS Chem Neurosci 2023; 14:4344-4351. [PMID: 38061891 PMCID: PMC10741654 DOI: 10.1021/acschemneuro.3c00539] [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: 08/16/2023] [Revised: 11/21/2023] [Accepted: 11/22/2023] [Indexed: 12/21/2023] Open
Abstract
Positron emission tomography (PET) probes are specific and sensitive while suffering from radiation risk. It is worthwhile to explore the chemical emission saturation transfer (CEST) effects of the probe prototypes and repurpose them for CEST imaging to avoid radiation. In this study, we used 11C-PiB as an example of a PET probe for detecting amyloid and tested the feasibility of repurposing this PET probe prototype, PiB, for CEST imaging. After optimizing the parameters through preliminary phantom experiments, we used APP/PS1 transgenic mice and age-matched C57 mice for in vivo CEST magnetic resonance imaging (MRI) of amyloid. Furthermore, the pathological assessment was conducted on the same brain slices to evaluate the correlation between the CEST MRI signal abnormality and β-amyloid deposition detected by immunohistochemical staining. In our results, the Z-spectra revealed an apparent CEST effect that peaked at approximately 6 ppm. APP/PS1 mice as young as 9 months injected with PiB showed a significantly higher CEST effect compared to the control groups. The hyperintense region was correlated with the Aβ deposition shown by pathological staining. In conclusion, repurposing the PET probe prototype for CEST MRI imaging is feasible and enables label- and radiation-free detection of the amyloid while maintaining the sensitivity and specificity of the ligand. This study opens the door to developing CEST probes based on PET probe prototypes.
Collapse
Affiliation(s)
- Caiyu Zhuang
- Department
of Radiology, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041, China
- Department
of Radiology, First Affiliated Hospital, Shantou University Medical College, Shantou 515041, China
| | - Beibei Chen
- Department
of Radiology, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041, China
| | - Shuohua Wu
- Department
of Radiology, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041, China
| | - Liang Xu
- Department
of Medical Imaging, Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen 518107, China
| | - Xiaolei Zhang
- Department
of Radiology, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041, China
| | - Xinhui Zheng
- Department
of Radiology, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041, China
| | - Yue Chen
- Department
of Radiology, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041, China
| | - Yiqun Geng
- Laboratory
of Molecular Pathology, Shantou University
Medical College, Shantou 515041, China
| | - Jitian Guan
- Department
of Radiology, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041, China
| | - Yan Lin
- Department
of Radiology, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041, China
- Provincial
Key Laboratory for Breast Cancer Diagnosis and Treatment, Shantou 515041, China
| | - Alan H. Wilman
- The Department
of Biomedical Engineering, University of
Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Renhua Wu
- Department
of Radiology, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041, China
- Provincial
Key Laboratory for Breast Cancer Diagnosis and Treatment, Shantou 515041, China
| |
Collapse
|
3
|
Zeng Z, Dong Y, Zou L, Xu D, Luo X, Chu T, Wang J, Ren Q, Liu Q, Li X. GluCEST Imaging and Structural Alterations of the Bilateral Hippocampus in First-Episode and Early-Onset Major Depression Disorder. J Magn Reson Imaging 2023; 58:1431-1440. [PMID: 36808678 DOI: 10.1002/jmri.28651] [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: 12/02/2022] [Revised: 02/05/2023] [Accepted: 02/06/2023] [Indexed: 02/22/2023] Open
Abstract
BACKGROUND Glutamate dysregulation is one of the key pathogenic mechanisms of major depressive disorder (MDD), and glutamate chemical exchange saturation transfer (GluCEST) has been used for glutamate measurement in some brain diseases but rarely in depression. PURPOSE To investigate the GluCEST changes in hippocampus in MDD and the relationship between glutamate and hippocampal subregional volumes. STUDY TYPE Cross-sectional. SUBJECTS Thirty-two MDD patients (34% males; 22.03 ± 7.21 years) and 47 healthy controls (HCs) (43% males; 22.00 ± 3.28 years). FIELD STRENGTH/SEQUENCE 3.0 T; magnetization prepared rapid gradient echo (MPRAGE) for three-dimensional T1-weighted images, two-dimensional turbo spin echo GluCEST, and multivoxel chemical shift imaging (CSI) for proton magnetic resonance spectroscopy (1 H MRS). ASSESSMENT GluCEST data were quantified by magnetization transfer ratio asymmetry (MTRasym ) analysis and assessed by the relative concentration of 1 H MRS-measured glutamate. FreeSurfer was used for hippocampus segmentation. STATISTICAL TESTS The independent sample t test, Mann-Whitney U test, Spearman's correlation, and partial correlation analysis were used. P < 0.05 was considered statistically significant. RESULTS In the left hippocampus, GluCEST values were significantly decreased in MDD (2.00 ± 1.08 [MDD] vs. 2.62 ± 1.41 [HCs]) and showed a significantly positive correlation with Glx/Cr (r = 0.37). GluCEST values were significantly positively correlated with the volumes of CA1 (r = 0.40), subiculum (r = 0.40) in the left hippocampus and CA1 (r = 0.51), molecular_layer_HP (r = 0.50), GC-ML-DG (r = 0.42), CA3 (r = 0.44), CA4 (r = 0.44), hippocampus-amygdala-transition-area (r = 0.46), and the whole hippocampus (r = 0.47) in the right hippocampus. Hamilton Depression Rating Scale scores showed significantly negative correlations with the volumes of the left presubiculum (r = -0.40), left parasubiculum (r = -0.47), and right presubiculum (r = -0.41). DATA CONCLUSION GluCEST can be used to measure glutamate changes and help to understand the mechanism of hippocampal volume loss in MDD. Hippocampal volume changes are associated with disease severity. LEVEL OF EVIDENCE 2 TECHNICAL EFFICACY: Stage 1.
Collapse
Affiliation(s)
- Zhen Zeng
- School of Medical Imaging, Binzhou Medical University, Yantai, China
| | - Yingying Dong
- Department of Psychology, Binzhou Medical University Hospital, Binzhou, China
| | - Linxuan Zou
- School of Medical Imaging, Binzhou Medical University, Yantai, China
| | - Donghao Xu
- School of Medical Imaging, Binzhou Medical University, Yantai, China
| | - Xunrong Luo
- Department of Radiology, Cancer Hospital of Chongqing University, Chongqing, China
| | - Tongpeng Chu
- Department of Radiology, Yantai Yuhuangding Hospital, Affiliated Hospital of Qingdao University, Yantai, China
| | - Jing Wang
- Department of Radiology, Binzhou Medical University Hospital, Binzhou, China
| | - Qingfa Ren
- School of Medical Imaging, Binzhou Medical University, Yantai, China
| | - Quanyuan Liu
- Department of Radiology, Binzhou Medical University Hospital, Binzhou, China
| | - Xianglin Li
- School of Medical Imaging, Binzhou Medical University, Yantai, China
| |
Collapse
|
4
|
Muñoz-Ballester C, Robel S. Astrocyte-mediated mechanisms contribute to traumatic brain injury pathology. WIREs Mech Dis 2023; 15:e1622. [PMID: 37332001 PMCID: PMC10526985 DOI: 10.1002/wsbm.1622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Revised: 05/25/2023] [Accepted: 05/29/2023] [Indexed: 06/20/2023]
Abstract
Astrocytes respond to traumatic brain injury (TBI) with changes to their molecular make-up and cell biology, which results in changes in astrocyte function. These changes can be adaptive, initiating repair processes in the brain, or detrimental, causing secondary damage including neuronal death or abnormal neuronal activity. The response of astrocytes to TBI is often-but not always-accompanied by the upregulation of intermediate filaments, including glial fibrillary acidic protein (GFAP) and vimentin. Because GFAP is often upregulated in the context of nervous system disturbance, reactive astrogliosis is sometimes treated as an "all-or-none" process. However, the extent of astrocytes' cellular, molecular, and physiological adjustments is not equal for each TBI type or even for each astrocyte within the same injured brain. Additionally, new research highlights that different neurological injuries and diseases result in entirely distinctive and sometimes divergent astrocyte changes. Thus, extrapolating findings on astrocyte biology from one pathological context to another is problematic. We summarize the current knowledge about astrocyte responses specific to TBI and point out open questions that the field should tackle to better understand how astrocytes shape TBI outcomes. We address the astrocyte response to focal versus diffuse TBI and heterogeneity of reactive astrocytes within the same brain, the role of intermediate filament upregulation, functional changes to astrocyte function including potassium and glutamate homeostasis, blood-brain barrier maintenance and repair, metabolism, and reactive oxygen species detoxification, sex differences, and factors influencing astrocyte proliferation after TBI. This article is categorized under: Neurological Diseases > Molecular and Cellular Physiology.
Collapse
Affiliation(s)
- Carmen Muñoz-Ballester
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Stefanie Robel
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| |
Collapse
|
5
|
Cember ATJ, Nanga RPR, Reddy R. Glutamate-weighted CEST (gluCEST) imaging for mapping neurometabolism: An update on the state of the art and emerging findings from in vivo applications. NMR IN BIOMEDICINE 2023; 36:e4780. [PMID: 35642353 DOI: 10.1002/nbm.4780] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 05/27/2022] [Accepted: 05/30/2022] [Indexed: 05/23/2023]
Abstract
Glutamate is the primary excitatory neurotransmitter in the mammalian central nervous system. As such, its proper regulation is essential to the healthy function of the human brain, and dysregulation of glutamate metabolism and compartmentalization underlies numerous neurological and neuropsychiatric pathologies. Glutamate-weighted chemical exchange saturation transfer (gluCEST) MRI is one of the only ways to non-invasively observe the relative concentration and spatial distribution of glutamate in the human brain. In the past 10 years, gluCEST has developed from a proof-of-concept experiment carried out in imaging phantoms and model systems to an increasingly sophisticated technique applied to reveal deviations from baseline neural metabolism in human beings, most notably in patients experiencing seizures of various origins or those on the psychosis spectrum. This article traces that progress, including in-depth discussion of the technical specifics of gluCEST and potential challenges to performing these experiments rigorously. We discuss the neurobiological context of glutamate, including the widely accepted hypotheses and models in the literature regarding its involvement in neurodegenerative diseases and other pathology. We then review the state of the art of in vivo glutamate detection by magnetic resonance imaging and the limitations on this front of in vivo MR spectroscopy. The gluCEST experiment is introduced and its advantages, challenges and limitations are thoroughly explored, beginning with the phantom experiment results demonstrated in the initial publication, through the latest approaches to correcting human brain images for B1 inhomogeneity. We then give a comprehensive overview of preclinical applications demonstrated to date, including Alzheimer's disease, Parkinson's disease, Huntington's disease, Traumatic brain injury and cancer, followed by a similar discussion of human studies. Finally, we highlight emerging applications, and discuss technical improvements on the horizon that hold promise for improving the robustness and versatility of gluCEST and its increasing presence in the arena of translational and precision medicine.
Collapse
Affiliation(s)
- Abigail T J Cember
- Center for Advanced Metabolic Imaging in Precision Medicine (CAMIPM), Department of Radiology, University of Pennsylvania
| | - Ravi Prakash Reddy Nanga
- Center for Advanced Metabolic Imaging in Precision Medicine (CAMIPM), Department of Radiology, University of Pennsylvania
| | - Ravinder Reddy
- Center for Advanced Metabolic Imaging in Precision Medicine (CAMIPM), Department of Radiology, University of Pennsylvania
| |
Collapse
|
6
|
Dai Z, Yang Z, Li Z, Li M, Sun H, Zhuang Z, Yang W, Hu Z, Chen X, Lin D, Wu X. Increased glymphatic system activity in patients with mild traumatic brain injury. Front Neurol 2023; 14:1148878. [PMID: 37251219 PMCID: PMC10213560 DOI: 10.3389/fneur.2023.1148878] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 04/24/2023] [Indexed: 05/31/2023] Open
Abstract
Purpose This study aims to investigate the glymphatic system activity changes in patients with mild traumatic brain injury (mTBI), particularly in MRI-negative patients, using analysis along the perivascular space (ALPS) technology. Methods A total of 161 mTBI patients (age: 15-92 years old) and 28 healthy controls (age: 15-84 years old) were included in this retrospective study. The mTBI patients were divided into MRI-negative and MRI-positive groups. ALPS index was calculated automatically using whole-brain T1-MPRAGE imaging and diffusion tensor imaging. The Student's t and chi-squared tests were performed to compare the ALPS index, age, gender, course of disease, and Glasgow Coma Scale (GCS) score between groups. Correlations among ALPS index, age, course of disease and GCS score were computed using Spearman's correlation analysis. Results Increased activity of the glymphatic system was suggested in mTBI patients based on ALPS index analysis, including the MRI-negative patients. There was a significant negative correlation between the ALPS index and age. In addition, a weak positive correlation between the ALPS index and course of disease was also observed. On the contrary, there was no significant correlation between the ALPS index and sex nor between the ALPS index and GCS score. Conclusion Our study demonstrated that the activity level of the glymphatic system was enhanced in mTBI patients, even when their brain MRI scans were negative. These findings may provide novel insights for understanding the pathophysiology of mild TBI.
Collapse
Affiliation(s)
- Zhuozhi Dai
- Department of Radiology, Shantou Central Hospital, Shantou, Guangdong, China
- Department of Radiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Zhiqi Yang
- Department of Radiology, Meizhou People's Hospital, Meizhou, Guangdong, China
| | - Zhaolin Li
- Department of Pulmonary and Critical Care Medicine, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Mu Li
- Department of Neurosurgery, Second Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong, China
| | - Hongfu Sun
- School of Information Technology and Electrical Engineering, University of Queensland, Brisbane, QLD, Australia
| | - Zerui Zhuang
- Department of Neurosurgery, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Weichao Yang
- Department of Radiology, Meizhou People's Hospital, Meizhou, Guangdong, China
| | - Zehuan Hu
- Department of Radiology, Shantou Central Hospital, Shantou, Guangdong, China
| | - Xiaofeng Chen
- Department of Radiology, Meizhou People's Hospital, Meizhou, Guangdong, China
| | - Daiying Lin
- Department of Radiology, Shantou Central Hospital, Shantou, Guangdong, China
| | - Xianheng Wu
- Department of Radiology, Shantou Central Hospital, Shantou, Guangdong, China
| |
Collapse
|
7
|
Hameed MQ, Hodgson N, Lee HHC, Pascual-Leone A, MacMullin PC, Jannati A, Dhamne SC, Hensch TK, Rotenberg A. N-acetylcysteine treatment mitigates loss of cortical parvalbumin-positive interneuron and perineuronal net integrity resulting from persistent oxidative stress in a rat TBI model. Cereb Cortex 2023; 33:4070-4084. [PMID: 36130098 PMCID: PMC10068300 DOI: 10.1093/cercor/bhac327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 07/26/2022] [Accepted: 07/27/2022] [Indexed: 11/12/2022] Open
Abstract
Traumatic brain injury (TBI) increases cerebral reactive oxygen species production, which leads to continuing secondary neuronal injury after the initial insult. Cortical parvalbumin-positive interneurons (PVIs; neurons responsible for maintaining cortical inhibitory tone) are particularly vulnerable to oxidative stress and are thus disproportionately affected by TBI. Systemic N-acetylcysteine (NAC) treatment may restore cerebral glutathione equilibrium, thus preventing post-traumatic cortical PVI loss. We therefore tested whether weeks-long post-traumatic NAC treatment mitigates cortical oxidative stress, and whether such treatment preserves PVI counts and related markers of PVI integrity and prevents pathologic electroencephalographic (EEG) changes, 3 and 6 weeks after fluid percussion injury in rats. We find that moderate TBI results in persistent oxidative stress for at least 6 weeks after injury and leads to the loss of PVIs and the perineuronal net (PNN) that surrounds them as well as of per-cell parvalbumin expression. Prolonged post-TBI NAC treatment normalizes the cortical redox state, mitigates PVI and PNN loss, and - in surviving PVIs - increases per-cell parvalbumin expression. NAC treatment also preserves normal spectral EEG measures after TBI. We cautiously conclude that weeks-long NAC treatment after TBI may be a practical and well-tolerated treatment strategy to preserve cortical inhibitory tone post-TBI.
Collapse
Affiliation(s)
- Mustafa Q Hameed
- F.M. Kirby Neurobiology Center, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
- Neuromodulation Program, Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
- Department of Neurosurgery, Boston Children’s Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
| | - Nathaniel Hodgson
- F.M. Kirby Neurobiology Center, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
| | - Henry H C Lee
- F.M. Kirby Neurobiology Center, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
- Rosamund Stone Zander Translational Neuroscience Center, Boston Children’s Hospital, 300 Longwood Avenue, Boston, MA 02115, United States
| | - Andres Pascual-Leone
- F.M. Kirby Neurobiology Center, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
- Neuromodulation Program, Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
| | - Paul C MacMullin
- F.M. Kirby Neurobiology Center, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
- Neuromodulation Program, Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
| | - Ali Jannati
- F.M. Kirby Neurobiology Center, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
- Neuromodulation Program, Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
| | - Sameer C Dhamne
- F.M. Kirby Neurobiology Center, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
- Neuromodulation Program, Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
| | - Takao K Hensch
- F.M. Kirby Neurobiology Center, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
- Department of Molecular & Cellular Biology, Center for Brain Science, Harvard University, 52 Oxford Street, Cambridge, MA 02138, United States
| | - Alexander Rotenberg
- F.M. Kirby Neurobiology Center, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
- Neuromodulation Program, Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
- Rosamund Stone Zander Translational Neuroscience Center, Boston Children’s Hospital, 300 Longwood Avenue, Boston, MA 02115, United States
| |
Collapse
|
8
|
Exosomes derived from bone marrow mesenchymal stem cells attenuate neurological damage in traumatic brain injury by alleviating glutamate-mediated excitotoxicity. Exp Neurol 2022; 357:114182. [PMID: 35901975 DOI: 10.1016/j.expneurol.2022.114182] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 07/08/2022] [Accepted: 07/21/2022] [Indexed: 12/12/2022]
Abstract
BACKGROUND Traumatic brain injury (TBI) is one of the major contributors to disability and death worldwide. Glutamate-mediated excitotoxicity, one of the secondary injuries occurring after TBI, leads to extreme neuronal apoptosis, and can be a potential target for intervention. Bone marrow mesenchymal stem cells-derived exosomes (BMSCs-Exos) have demonstrated neuroprotective effects on TBI. However, their precise role and the underlying mechanism by which they regulate glutamate-mediated excitotoxicity have not yet been determined. Therefore, this study aimed to determine whether BMSCs-Exos alleviate glutamate excitotoxicity post-TBI and their associated mechanism. METHODS BMSCs-Exos were extracted from the BMSCs incubation medium and identified by transmission electron microscopy, nanoparticle trafficking analysis, and western blotting. The neuroprotective effects of BMSCs-Exos on glutamate excitotoxicity were investigated in the glutamate-mediated excitotoxicity neuronal cell model and the TBI rat model (TBI induced by controlled cortical impact) using western blotting and TUNEL assay. Cortical lesion samples were collected post-TBI on day-1 and day-14 to study histology. In addition, cortical lesion volume on days 1, 3 and 7 following TBI was determined using T2-weighted magnetic resonance imaging (MRI), and cognitive function was assessed at 4 weeks following TBI using the Morris water maze (MWM) test. RESULTS BMSC-Exos were observed to be spherical with a mean diameter of 109.9 nm, and expressed exosomal markers CD9, CD81 and TSg101. BMSCs-Exos were efficiently endocytosed by astrocytes after co-incubation for 24 h. In vitro studies revealed that 125 μM of glutamate significantly induced neuronal apoptosis, which was attenuated by BMSCs-Exos in astrocyte-neuron co-cultures. This attenuation was mediated by the upregulation of glutamate transporter-1 (GLT-1) level and the downregulation of p-p38 MAPK level in astrocytes. Similar results were obtained in vivo, wherein we verified that PKH67-labeled BMSCs-Exos administered intravenously could reach the perilesional cortex crossing the blood-brain barrier and significantly reduce glutamate levels in the perilesional cortex of the TBI rat, accompanied by increased GLT-1 level and downregulation in p-p38 MAPK level. Additionally, western blotting and TUNEL staining also revealed that BMSCs-Exos significantly downregulated the expression of pro-apoptosis markers, including cleaved caspase-3 and cleaved caspase-9, and attenuated neuronal apoptosis following TBI. Immunohistochemical analysis and Nissl staining showed that BMSCs-Exos significantly increased GLT-1-positive cells, and the number of apoptotic neurons decreased in the perilesional cortex. Moreover, MRI and MWM results revealed that BMSCs-Exos significantly minimized cortical lesion volume and ameliorated cognitive function after TBI. The underlying neuroprotective mechanism of BMSCs-Exos may be due to an increase in GLT-1 level in astrocytes by blocking the p38 MAPK signaling pathway. CONCLUSION Taken together, our findings demonstrate that the implementation of BMSCs-Exos may be an effective prospective therapy for attenuating post-TBI neurological damage.
Collapse
|
9
|
Xu Y, Zhuang Z, Zheng H, Shen Z, Gao Q, Lin Q, Fan R, Luo L, Zheng W. Glutamate Chemical Exchange Saturation Transfer (GluCEST) Magnetic Resonance Imaging of Rat Brain With Acute Carbon Monoxide Poisoning. Front Neurol 2022; 13:865970. [PMID: 35665050 PMCID: PMC9160993 DOI: 10.3389/fneur.2022.865970] [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: 02/04/2022] [Accepted: 04/05/2022] [Indexed: 02/05/2023] Open
Abstract
OBJECTIVES To evaluate the diagnostic and prognostic values of glutamate chemical exchange saturation transfer (GluCEST) magnetic resonance imaging as a quantitative method for pathogenetic research and clinical application of carbon monoxide (CO) poisoning-induced encephalopathy combined with the proton magnetic resonance spectroscopy (1H-MRS) and the related histopathological and behavioral changes. METHODS A total of 63 Sprague-Dawley rats were randomly divided into four groups. Group A (n = 12) was used for animal modeling verification; Group B (n = 15) was used for magnetic resonance molecular imaging, Group C (n = 15) was used for animal behavior experiments, and Group D (n = 21) was used for histopathological examination. All the above quantitative results were analyzed by statistics. RESULTS The peak value of carboxyhemoglobin saturation in the blood after modeling was 7.3-fold higher than before and lasted at least 2.5 h. The GluCEST values of the parietal lobe, hippocampus, and thalamus were significantly higher than the base values in CO poisoning rats (p < 0.05) and the 1H-MRS showed significant differences in the parietal lobe and hippocampus. In the Morris water maze tests, the average latency and distance were significantly prolonged in poisoned rats (p < 0.05), and the cumulative time was shorter and negatively correlated with GluCEST. CONCLUSION The GluCEST imaging non-invasively reflects the changes of glutamate in the brain in vivo with higher sensitivity and spatial resolution than 1H-MRS. Our study implies that GluCEST imaging may be used as a new imaging method for providing a pathogenetic and prognostic assessment of CO-associated encephalopathy.
Collapse
Affiliation(s)
- Yuan Xu
- Department of Radiology, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Zerui Zhuang
- Department of Neurosurgery, The Second Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Hongyi Zheng
- Department of Radiology, The Second Affiliated Hospital of Shantou University Medical College, Shantou, China
| | | | - Qilu Gao
- Department of Radiology, The Second Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Qihuan Lin
- Department of Radiology, The Second Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Rong Fan
- Department of Radiology, The Second Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Liangping Luo
- Department of Radiology, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Wenbin Zheng
- Department of Radiology, The Second Affiliated Hospital of Shantou University Medical College, Shantou, China
| |
Collapse
|
10
|
BADE AN, GENDELMAN HE, MCMILLAN J, LIU Y. Chemical exchange saturation transfer for detection of antiretroviral drugs in brain tissue. AIDS 2021; 35:1733-1741. [PMID: 34049358 PMCID: PMC8373768 DOI: 10.1097/qad.0000000000002960] [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] [Indexed: 10/21/2022]
Abstract
OBJECTIVE Antiretroviral drug theranostics facilitates the monitoring of biodistribution and efficacy of therapies designed to target HIV type-1 (HIV-1) reservoirs. To this end, we have now deployed intrinsic drug chemical exchange saturation transfer (CEST) contrasts to detect antiretroviral drugs within the central nervous system (CNS). DESIGN AND METHODS CEST effects for lamivudine (3TC) and emtricitabine (FTC) were measured by asymmetric magnetization transfer ratio analyses. The biodistribution of 3TC in different brain sub-regions of C57BL/6 mice treated with lipopolysaccharides was determined using MRI. CEST effects of 3TC protons were quantitated by Lorentzian fitting analysis. 3TC levels in plasma and brain regions were measured using ultraperformance liquid chromatography tandem mass spectrometry to affirm the CEST test results. RESULTS CEST effects of the hydroxyl and amino protons in 3TC and FTC linearly correlated to drug concentrations. 3TC was successfully detected in vivo in brain sub-regions by MRI. The imaging results were validated by measurements of CNS drug concentrations. CONCLUSION CEST contrasts can be used to detect antiretroviral drugs using MRI. Such detection can be used to assess spatial--temporal drug biodistribution. This is most notable within the CNS where drug biodistribution may be more limited with the final goal of better understanding antiretroviral drug-associated efficacy and potential toxicity.
Collapse
Affiliation(s)
- Aditya N. BADE
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198 USA
| | - Howard E. GENDELMAN
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198 USA
| | - JoEllyn MCMILLAN
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198 USA
| | - Yutong LIU
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198 USA
- Department of Radiology, University of Nebraska Medical Center, Omaha, NE 68198 USA
| |
Collapse
|
11
|
Dai Z, Kalra S, Mah D, Seres P, Sun H, Wu R, Wilman AH. Amide signal intensities may be reduced in the motor cortex and the corticospinal tract of ALS patients. Eur Radiol 2021; 31:1401-1409. [PMID: 32909054 DOI: 10.1007/s00330-020-07243-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 07/21/2020] [Accepted: 08/28/2020] [Indexed: 02/05/2023]
Abstract
OBJECTIVES The aim of the study is to assess amide concentration changes in ALS patients compared with healthy controls by using quantitative amide proton transfer (APT) and multiparameter magnetic resonance imaging, and testing its correlation with clinical scores. METHODS Sixteen ALS patients and sixteen healthy controls were recruited as part of the Canadian ALS Neuroimaging Consortium, and multimodal magnetic resonance imaging was performed at 3 T, including APT and diffusion imaging. Lorentz fitting was used to quantify the amide effect. Clinical disability was evaluated using the revised ALS functional rating scale (ALSFRS-R), and its correlation with image characteristics was assessed. The diagnostic performance of different imaging parameters was evaluated with receiver operating characteristic analysis. RESULTS Our results showed that the amide peak was significantly different between the motor cortex and other gray matter territories within the brain of ALS patients (p < 0.001). Compared with controls, amide signal intensities in ALS were significantly reduced in the motor cortex (p < 0.001) and corticospinal tract (p = 0.046), while abnormalities were not detected using routine imaging methods. There was no significant correlation between amide and ALSFRS-R score. The diagnostic accuracy of the amide peak was superior to that of diffusion imaging. CONCLUSIONS This study demonstrated changes of amide signal intensities in the motor cortex and corticospinal tract of ALS patients. KEY POINTS • The neurodegenerative disease amyotrophic lateral sclerosis (ALS) has a lack of objective imaging indicators for diagnosis and assessment. • Analysis of amide proton transfer imaging revealed changes in the motor cortex and corticospinal tract of ALS patients that were not visible on standard magnetic resonance imaging. • The diagnostic accuracy of the amide peak was superior to that of diffusion imaging.
Collapse
Affiliation(s)
- Zhuozhi Dai
- Department of Radiology, 2nd Affiliated Hospital of Shantou University Medical College, Shantou, 515041, Guangdong, China
- Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, T6G 2V2, Canada
| | - Sanjay Kalra
- Department of Medicine (Neurology), University of Alberta, Edmonton, Alberta, T6G 2S2, Canada
| | - Dennell Mah
- Department of Medicine (Neurology), University of Alberta, Edmonton, Alberta, T6G 2S2, Canada
| | - Peter Seres
- Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, T6G 2V2, Canada
| | - Hongfu Sun
- School of Information Technology and Electrical Engineering, University of Queensland, Brisbane, Queensland, 4072, Australia
| | - Renhua Wu
- Department of Radiology, 2nd Affiliated Hospital of Shantou University Medical College, Shantou, 515041, Guangdong, China.
| | - Alan H Wilman
- Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, T6G 2V2, Canada.
| |
Collapse
|
12
|
Zeng H, Zhang X, Wang W, Shen Z, Dai Z, Yu Z, Xu S, Yan G, Huang Q, Wu R, Chen X, Xu H. Maternal separation with early weaning impairs neuron-glia integrity: non-invasive evaluation and substructure demonstration. Sci Rep 2020; 10:19440. [PMID: 33173142 PMCID: PMC7656452 DOI: 10.1038/s41598-020-76640-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 10/29/2020] [Indexed: 02/05/2023] Open
Abstract
Astrocytes and oligodendrocytes play essential roles in regulating neural signal transduction along neural circuits in CNS. The perfect coordination of neuron/astrocyte and neuron/oligodendrocyte entities was termed as neuron-glia integrity recently. Here we monitored the status of neuron-glia integrity via non-invasive neuroimaging methods and demonstrated the substructures of it using other approaches in an animal model of maternal separation with early weaning (MSEW), which mimics early life neglect and abuse in humans. Compared to controls, MSEW rats showed higher glutamate level, but lower GABA in prefrontal cortex (PFC) detected by chemical exchange saturation transfer and 1H-MRS methods, lower levels of glial glutamate transporter-1 and ATP-α, but increased levels of glutamate decarboxylase-65 and glutamine synthetase in PFC; reduced fractional anisotropy in various brain regions revealed by diffusion tensor imaging, along with increased levels of N-acetyl-aspartate measured by 1H-MRS; and hypomyelination in PFC as evidenced by relevant cellular and molecular changes.
Collapse
Affiliation(s)
- Haiyan Zeng
- The Mental Health Center, Shantou University Medical College, Shantou, China
- Xianyue Hospital/Xiamen Mental Health Center, Xiamen, China
| | - Xiaolei Zhang
- Department of Medical Imaging, The Second Affiliated Hospital, Shantou University Medical College, Shantou, China
| | - Wenqiang Wang
- Xianyue Hospital/Xiamen Mental Health Center, Xiamen, China
| | - Zhiwei Shen
- Department of Medical Imaging, The Second Affiliated Hospital, Shantou University Medical College, Shantou, China
| | - Zhuozhi Dai
- Department of Medical Imaging, The Second Affiliated Hospital, Shantou University Medical College, Shantou, China
| | - Zhijia Yu
- The Mental Health Center, Shantou University Medical College, Shantou, China
| | - Shuqin Xu
- Department of Anatomy, Shantou University Medical College, Shantou, China
| | - Gen Yan
- Department of Medical Imaging, The Second Affiliated Hospital, Shantou University Medical College, Shantou, China
| | - Qingjun Huang
- The Mental Health Center, Shantou University Medical College, Shantou, China
| | - Renhua Wu
- Department of Medical Imaging, The Second Affiliated Hospital, Shantou University Medical College, Shantou, China
| | - Xi Chen
- McLean Imaging Center, McLean Hospital, Harvard Medical School, Belmont, USA
| | - Haiyun Xu
- The Mental Health Center, Shantou University Medical College, Shantou, China.
- Department of Anatomy, Shantou University Medical College, Shantou, China.
- The School of Psychiatry, Wenzhou Medical University, Wenzhou, China.
| |
Collapse
|
13
|
|
14
|
Lee DW, Woo CW, Woo DC, Kim JK, Kim KW, Lee DH. Regional Mapping of Brain Glutamate Distributions Using Glutamate-Weighted Chemical Exchange Saturation Transfer Imaging. Diagnostics (Basel) 2020; 10:E571. [PMID: 32784483 PMCID: PMC7459654 DOI: 10.3390/diagnostics10080571] [Citation(s) in RCA: 2] [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: 06/30/2020] [Revised: 08/06/2020] [Accepted: 08/06/2020] [Indexed: 01/24/2023] Open
Abstract
PURPOSE To investigate glutamate signal distributions in multiple brain regions of a healthy rat brain using glutamate-weighted chemical exchange saturation transfer (GluCEST) imaging. METHOD The GluCEST data were obtained using a 7.0 T magnetic resonance imaging (MRI) scanner, and all data were analyzed using conventional magnetization transfer ratio asymmetry in eight brain regions (cortex, hippocampus, corpus callosum, and rest of midbrain in each hemisphere). GluCEST data acquisition was performed again one month later in five randomly selected rats to evaluate the stability of the GluCEST signal. To evaluate glutamate level changes calculated by GluCEST data, we compared the results with the concentration of glutamate acquired from 1H magnetic resonance spectroscopy (1H MRS) data in the cortex and hippocampus. RESULTS GluCEST signals showed significant differences (all p ≤ 0.001) between the corpus callosum (-1.71 ± 1.04%; white matter) and other brain regions (3.59 ± 0.41%, cortex; 5.47 ± 0.61%, hippocampus; 4.49 ± 1.11%, rest of midbrain; gray matter). The stability test of GluCEST findings for each brain region was not significantly different (all p ≥ 0.263). In line with the GluCEST results, glutamate concentrations measured by 1H MRS also appeared higher in the hippocampus (7.30 ± 0.16 μmol/g) than the cortex (6.89 ± 0.72 μmol/g). CONCLUSION Mapping of GluCEST signals in the healthy rat brain clearly visualize glutamate distributions. These findings may yield a valuable database and insights for comparing glutamate signal changes in pre-clinical brain diseases.
Collapse
Affiliation(s)
- Do-Wan Lee
- Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea; (D.-W.L.); (J.K.K.); (K.W.K.)
| | - Chul-Woong Woo
- Convergence Medicine Research Center, Asan Institute for Life Sciences, Asan Medical Center, Seoul 05505, Korea; (C.-W.W.); (D.-C.W.)
| | - Dong-Cheol Woo
- Convergence Medicine Research Center, Asan Institute for Life Sciences, Asan Medical Center, Seoul 05505, Korea; (C.-W.W.); (D.-C.W.)
- Department of Convergence Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Jeong Kon Kim
- Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea; (D.-W.L.); (J.K.K.); (K.W.K.)
| | - Kyung Won Kim
- Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea; (D.-W.L.); (J.K.K.); (K.W.K.)
| | - Dong-Hoon Lee
- Department of Radiation Convergence Engineering, Yonsei University, Wonju 26493, Korea
| |
Collapse
|
15
|
Chen Y, Dai Z, Fan R, Mikulis DJ, Qiu J, Shen Z, Wang R, Lai L, Tang Y, Li Y, Jia Y, Yan G, Wu R. Glymphatic System Visualized by Chemical-Exchange-Saturation-Transfer Magnetic Resonance Imaging. ACS Chem Neurosci 2020; 11:1978-1984. [PMID: 32492333 DOI: 10.1021/acschemneuro.0c00222] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Dysfunction of the glymphatic system may play a significant role in the development of neurodegenerative diseases. However, in vivo imaging of the glymphatic system is challenging. In this study, we describe an unconventional MRI method for imaging the glymphatic system based on chemical exchange saturation transfer, which we tested in an in vivo porcine model of impaired glymphatic function. The blood, lymph, and cerebrospinal fluid (CSF) from one pig were used for testing the MRI effect in vitro at 7 Tesla (T). Unilateral deep cervical lymph node ligation models were then performed in 20 adult male Sprague-Dawley rats. The brains were scanned in vivo dynamically after surgery using the new MRI method. Behavioral tests were performed after each scanning session and the results were tested for correlations with the MRI signal intensity. Finally, the pathological assessment was conducted in the same brain slices. The special MRI effect in the lymph was evident at about 1.0 ppm in water and was distinguishable from those of blood and CSF. In the model group, the intensity of this MRI signal was significantly higher in the ipsilateral than in the contralateral hippocampus. The correlation between the signal abnormality and the behavioral score was significant (Pearson's, R2 = 0.9154, p < 0.005). We conclude that the novel MRI method can visualize the glymphatic system in vivo.
Collapse
Affiliation(s)
- Yuanfeng Chen
- Department of Radiology, the Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, P.R. China
| | - Zhuozhi Dai
- Department of Radiology, the Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, P.R. China
| | - Ruhang Fan
- Department of Pathology, Medical College of Shantou University, Guangdong, Shantou 515031, P.R. China
| | - David John Mikulis
- Division of Neuroradiology, Department of Medical Imaging, University Health Network, Toronto, Ontario M5T 2S7, Canada
| | - Jinming Qiu
- Department of Radiology, the Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, P.R. China
| | - Zhiwei Shen
- Department of Radiology, the Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, P.R. China
| | - Runrun Wang
- Department of Radiology, the Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, P.R. China
| | - Lihua Lai
- Department of Radiology, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, P. R. China
| | - Yanyan Tang
- Department of Radiology, the Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, P.R. China
| | - Yan Li
- Department of Radiology, the Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, P.R. China
| | - Yanlong Jia
- Department of Radiology, the Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, P.R. China
| | - Gen Yan
- Department of Radiology, the Second Affiliated Hospital of Xiamen Medical College, Xiamen, Fujian Province 361022, China
| | - Renhua Wu
- Department of Radiology, the Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, P.R. China
- Provincial Key Laboratory of Medical Molecular Imaging, Guangdong, Shantou 515041, P.R. China
| |
Collapse
|
16
|
Klein P, Friedman A, Hameed MQ, Kaminski RM, Bar-Klein G, Klitgaard H, Koepp M, Jozwiak S, Prince DA, Rotenberg A, Twyman R, Vezzani A, Wong M, Löscher W. Repurposed molecules for antiepileptogenesis: Missing an opportunity to prevent epilepsy? Epilepsia 2020; 61:359-386. [PMID: 32196665 PMCID: PMC8317585 DOI: 10.1111/epi.16450] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 01/26/2020] [Accepted: 01/27/2020] [Indexed: 12/11/2022]
Abstract
Prevention of epilepsy is a great unmet need. Acute central nervous system (CNS) insults such as traumatic brain injury (TBI), cerebrovascular accidents (CVA), and CNS infections account for 15%-20% of all epilepsy. Following TBI and CVA, there is a latency of days to years before epilepsy develops. This allows treatment to prevent or modify postinjury epilepsy. No such treatment exists. In animal models of acquired epilepsy, a number of medications in clinical use for diverse indications have been shown to have antiepileptogenic or disease-modifying effects, including medications with excellent side effect profiles. These include atorvastatin, ceftriaxone, losartan, isoflurane, N-acetylcysteine, and the antiseizure medications levetiracetam, brivaracetam, topiramate, gabapentin, pregabalin, vigabatrin, and eslicarbazepine acetate. In addition, there are preclinical antiepileptogenic data for anakinra, rapamycin, fingolimod, and erythropoietin, although these medications have potential for more serious side effects. However, except for vigabatrin, there have been almost no translation studies to prevent or modify epilepsy using these potentially "repurposable" medications. We may be missing an opportunity to develop preventive treatment for epilepsy by not evaluating these medications clinically. One reason for the lack of translation studies is that the preclinical data for most of these medications are disparate in terms of types of injury, models within different injury type, dosing, injury-treatment initiation latencies, treatment duration, and epilepsy outcome evaluation mode and duration. This makes it difficult to compare the relative strength of antiepileptogenic evidence across the molecules, and difficult to determine which drug(s) would be the best to evaluate clinically. Furthermore, most preclinical antiepileptogenic studies lack information needed for translation, such as dose-blood level relationship, brain target engagement, and dose-response, and many use treatment parameters that cannot be applied clinically, for example, treatment initiation before or at the time of injury and dosing higher than tolerated human equivalent dosing. Here, we review animal and human antiepileptogenic evidence for these medications. We highlight the gaps in our knowledge for each molecule that need to be filled in order to consider clinical translation, and we suggest a platform of preclinical antiepileptogenesis evaluation of potentially repurposable molecules or their combinations going forward.
Collapse
Affiliation(s)
- Pavel Klein
- Mid-Atlantic Epilepsy and Sleep Center, Bethesda, Maryland
| | - Alon Friedman
- Departments of Physiology and Cell Biology, and Brain and Cognitive Science, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Departments of Medical Neuroscience and Brain Repair Center, Dalhousie University, Halifax, Canada
| | - Mustafa Q. Hameed
- Neuromodulation Program, Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts
| | - Rafal M. Kaminski
- Neurosymptomatic Domains Section, Roche Pharma Research & Early Development, Roche Innovation Center, Basel, Switzerland
| | - Guy Bar-Klein
- McKusick-Nathans Institute of Genetic Medicine, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Henrik Klitgaard
- Neurosciences Therapeutic Area, UCB Pharma, Braine-l’Alleud, Belgium
| | - Mathias Koepp
- Department of Clinical and Experimental Epilepsy, University College London Institute of Neurology, London, UK
| | - Sergiusz Jozwiak
- Department of Pediatric Neurology, Warsaw Medical University, Warsaw, Poland
| | - David A. Prince
- Neurology and the Neurological Sciences, Stanford University School of Medicine, Stanford, California
| | - Alexander Rotenberg
- Neuromodulation Program, Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts
| | | | - Annamaria Vezzani
- Department of Neuroscience, Mario Negri Institute for Pharmacological Research, Scientific Institute for Research and Health Care, Milan, Italy
| | - Michael Wong
- Department of Neurology, Washington University School of Medicine, St Louis, Missouri
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany
- Center for Systems Neuroscience, Hannover, Germany
| |
Collapse
|
17
|
Jia Y, Chen Y, Geng K, Cheng Y, Li Y, Qiu J, Huang H, Wang R, Zhang Y, Wu R. Glutamate Chemical Exchange Saturation Transfer (GluCEST) Magnetic Resonance Imaging in Pre-clinical and Clinical Applications for Encephalitis. Front Neurosci 2020; 14:750. [PMID: 32848546 PMCID: PMC7399024 DOI: 10.3389/fnins.2020.00750] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Accepted: 06/25/2020] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Encephalitis is a common central nervous system inflammatory disease that seriously endangers human health owing to the lack of effective diagnostic methods, which leads to a high rate of misdiagnosis and mortality. Glutamate is implicated closely in microglial activation, and activated microglia are key players in encephalitis. Hence, using glutamate chemical exchange saturation transfer (GluCEST) imaging for the early diagnosis of encephalitis holds promise. METHODS The sensitivity of GluCEST imaging with different concentrations of glutamate and other major metabolites in the brain was validated in phantoms. Twenty-seven Sprague-Dawley (SD) rats with encephalitis induced by Staphylococcus aureus infection were used for preclinical research of GluCEST imaging in a 7.0-Tesla scanner. For the clinical study, six patients with encephalitis, six patients with lacunar infarction, and six healthy volunteers underwent GluCEST imaging in a 3.0-Tesla scanner. RESULTS The number of amine protons on glutamate that had a chemical shift of 3.0 ppm away from bulk water and the signal intensity of GluCEST were concentration-dependent. Under physiological conditions, glutamate is the main contributor to the GluCEST signal. Compared with normal tissue, in both rats and patients with encephalitis, the encephalitis areas demonstrated a hyper-intense GluCEST signal, while the lacunar infarction had a decreased GluCEST signal intensity. After intravenous immunoglobulin therapy, patients with encephalitis lesions showed a decrease in GluCEST signal, and the results were significantly different from the pre-treatment signal (1.34 ± 0.31 vs 5.0 ± 0.27%, respectively; p = 0.000). CONCLUSION Glutamate plays a role in encephalitis, and the GluCEST imaging signal has potential as an in vivo imaging biomarker for the early diagnosis of encephalitis. GluCEST will provide new insight into encephalitis and help improve the differential diagnosis of brain disorders.
Collapse
Affiliation(s)
- Yanlong Jia
- Department of Radiology, The Second Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Yanzi Chen
- Department of Radiology, Affiliated Longhua People’s Hospital, Southern Medical University, Shenzhen, China
| | - Kuan Geng
- Department of Radiology, The First People’s Hospital of Honghe Prefecture, Mengzi, China
| | - Yan Cheng
- Department of Radiology, The Second Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Yan Li
- Department of Radiology, The Second Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Jinming Qiu
- Department of Radiology, The Second Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Huaidong Huang
- Department of Radiology, The Second Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Runrun Wang
- Department of Radiology, The Second Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Yunping Zhang
- Department of Nuclear Medicine, Shenzhen Luohu District People’s Hospital, Shenzhen, China
- *Correspondence: Yunping Zhang,
| | - Renhua Wu
- Department of Radiology, The Second Affiliated Hospital of Shantou University Medical College, Shantou, China
- Renhua Wu,
| |
Collapse
|
18
|
Li R, Dai Z, Hu D, Zeng H, Fang Z, Zhuang Z, Xu H, Huang Q, Cui Y, Zhang H. Mapping the Alterations of Glutamate Using Glu-Weighted CEST MRI in a Rat Model of Fatigue. Front Neurol 2020; 11:589128. [PMID: 33250853 PMCID: PMC7673456 DOI: 10.3389/fneur.2020.589128] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 10/07/2020] [Indexed: 02/05/2023] Open
Abstract
Objective: Glutamate dysregulation may play an important role in the pathophysiology of fatigue. Glutamate weighted chemical exchange saturation transfer (Glu-weighted CEST) MRI is a recently developed technology which enables measuring glutamate in vivo with high sensitivity and spatial resolution. The purpose of this study is to map the alternations of brain glutamate in a rat model of fatigue. Methods: Rats were subjected to 10 days fatigue loading procedure (fatigue group) or reared without any fatigue loading (control group). Spontaneous activities of rats in the fatigue group were recorded from 3 days before fatigue loading to 4 days after the end of fatigue loading. Glu-weighted CEST were performed following 10-day fatigue loading. Results: Rats in the fatigue group exhibited significant reduced spontaneous activities after 10-day fatigue loading. The glutamate level in the whole brain increased significantly in the fatigue group compared to that in the control group. Further analysis of glutamate in the sub-regions of brain including the prefrontal cortex, hippocampus, and striatum revealed a trend of increment, although statistical significance was not reached. Significance: The increase of glutamate level in the brain may be a crucial process involved in the pathophysiology of fatigue.
Collapse
Affiliation(s)
- Ruili Li
- Department of Psychiatry, Mental Health Center of Shantou University, Shantou, China
| | - Zhuozhi Dai
- Department of Radiology, Shantou Central Hospital, Shantou, China
- Department of Radiology, The Second Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Di Hu
- Laboratory for Biofunction Dynamic Imaging, RIkagaku KENkyusho/Institute of Physical and Chemical Research (RIKEN) Center for Systems Dynamics Research, Kobe, Japan
| | - Haiyan Zeng
- Department of Psychiatry, Mental Health Center of Shantou University, Shantou, China
- Mental Health Center, Xianyue Hospital, Xiamen, China
| | - Zeman Fang
- Department of Psychiatry, Mental Health Center of Shantou University, Shantou, China
| | - Zerui Zhuang
- Department of Radiology, The Second Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Haiyun Xu
- Department of Psychiatry, Mental Health Center of Shantou University, Shantou, China
- School of Psychiatry, Wenzhou Medical University, Wenzhou, China
| | - Qingjun Huang
- Department of Psychiatry, Mental Health Center of Shantou University, Shantou, China
| | - Yilong Cui
- Mental Health Center, Xianyue Hospital, Xiamen, China
| | - Handi Zhang
- Department of Psychiatry, Mental Health Center of Shantou University, Shantou, China
- *Correspondence: Handi Zhang
| |
Collapse
|
19
|
Jia Y, Wang C, Zheng J, Lin G, Ni D, Shen Z, Huang B, Li Y, Guan J, Hong W, Chen Y, Wu R. Novel nanomedicine with a chemical-exchange saturation transfer effect for breast cancer treatment in vivo. J Nanobiotechnology 2019; 17:123. [PMID: 31847857 PMCID: PMC6918642 DOI: 10.1186/s12951-019-0557-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 12/10/2019] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Nanomedicine is a promising new approach to cancer treatment that avoids the disadvantages of traditional chemotherapy and improves therapeutic indices. However, the lack of a real-time visualization imaging technology to monitor drug distribution greatly limits its clinical application. Image-tracked drug delivery is of great clinical interest; it is useful for identifying those patients for whom the therapy is more likely to be beneficial. This paper discusses a novel nanomedicine that displays features of nanoparticles and facilitates functional magnetic resonance imaging but is challenging to prepare. RESULTS To achieve this goal, we synthesized an acylamino-containing amphiphilic block copolymer (polyethylene glycol-polyacrylamide-polyacetonitrile, PEG-b-P(AM-co-AN)) by reversible addition-fragmentation chain transfer (RAFT) polymerization. The PEG-b-P(AM-co-AN) has chemical exchange saturation transfer (CEST) effects, which enable the use of CEST imaging for monitoring nanocarrier accumulation and providing molecular information of pathological tissues. Based on PEG-b-P(AM-co-AN), a new nanomedicine PEG-PAM-PAN@DOX was constructed by nano-precipitation. The self-assembling nature of PEG-PAM-PAN@DOX made the synthesis effective, straightforward, and biocompatible. In vitro studies demonstrate decreased cytotoxicity of PEG-PAM-PAN@DOX compared to free doxorubicin (half-maximal inhibitory concentration (IC50), mean ~ 0.62 μg/mL vs. ~ 5 μg/mL), and the nanomedicine more efficiently entered the cytoplasm and nucleus of cancer cells to kill them. Further, in vivo animal experiments showed that the nanomedicine developed was not only effective against breast cancer, but also displayed an excellent sensitive CEST effect for monitoring drug accumulation (at about 0.5 ppm) in tumor areas. The CEST signal of post-injection 2 h was significantly higher than that of pre-injection (2.17 ± 0.88% vs. 0. 09 ± 0.75%, p < 0.01). CONCLUSIONS The nanomedicine with CEST imaging reflects the characterization of tumors and therapeutic functions has great potential medical applications.
Collapse
Affiliation(s)
- Yanlong Jia
- Department of Radiology, Second Affiliated Hospital, Shantou University Medical College, Shantou, 515041, People's Republic of China
| | - Chaochao Wang
- Shanghai Key Laboratory of Advanced Polymeric Materials, School of Chemistry and Molecular Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China
| | - Jiehua Zheng
- Department of General Surgery, Second Affiliated Hospital, Shantou University Medical College, Shantou, 515041, People's Republic of China
| | - Guisen Lin
- Department of Radiology, Second Affiliated Hospital, Shantou University Medical College, Shantou, 515041, People's Republic of China
| | - Dalong Ni
- Departments of Radiology and Medical Physics, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Zhiwei Shen
- Department of Radiology, Second Affiliated Hospital, Shantou University Medical College, Shantou, 515041, People's Republic of China
| | - Baoxuan Huang
- Shanghai Key Laboratory of Advanced Polymeric Materials, School of Chemistry and Molecular Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China
| | - Yan Li
- Department of Radiology, Second Affiliated Hospital, Shantou University Medical College, Shantou, 515041, People's Republic of China
| | - Jitian Guan
- Department of Radiology, Second Affiliated Hospital, Shantou University Medical College, Shantou, 515041, People's Republic of China
| | - Weida Hong
- Department of General Surgery, Second Affiliated Hospital, Shantou University Medical College, Shantou, 515041, People's Republic of China
| | - Yuanfeng Chen
- Department of Radiology, Second Affiliated Hospital, Shantou University Medical College, Shantou, 515041, People's Republic of China
| | - Renhua Wu
- Department of Radiology, Second Affiliated Hospital, Shantou University Medical College, Shantou, 515041, People's Republic of China.
| |
Collapse
|
20
|
Hameed MQ, Hsieh TH, Morales-Quezada L, Lee HHC, Damar U, MacMullin PC, Hensch TK, Rotenberg A. Ceftriaxone Treatment Preserves Cortical Inhibitory Interneuron Function via Transient Salvage of GLT-1 in a Rat Traumatic Brain Injury Model. Cereb Cortex 2019; 29:4506-4518. [PMID: 30590449 PMCID: PMC7150617 DOI: 10.1093/cercor/bhy328] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 11/26/2018] [Accepted: 11/28/2018] [Indexed: 12/16/2022] Open
Abstract
Traumatic brain injury (TBI) results in a decrease in glutamate transporter-1 (GLT-1) expression, the major mechanism for glutamate removal from synapses. Coupled with an increase in glutamate release from dead and dying neurons, this causes an increase in extracellular glutamate. The ensuing glutamate excitotoxicity disproportionately damages vulnerable GABAergic parvalbumin-positive inhibitory interneurons, resulting in a progressively worsening cortical excitatory:inhibitory imbalance due to a loss of GABAergic inhibitory tone, as evidenced by chronic post-traumatic symptoms such as epilepsy, and supported by neuropathologic findings. This loss of intracortical inhibition can be measured and followed noninvasively using long-interval paired-pulse transcranial magnetic stimulation with mechanomyography (LI-ppTMS-MMG). Ceftriaxone, a β-lactam antibiotic, is a potent stimulator of the expression of rodent GLT-1 and would presumably decrease excitotoxic damage to GABAergic interneurons. It may thus be a viable antiepileptogenic intervention. Using a rat fluid percussion injury TBI model, we utilized LI-ppTMS-MMG, quantitative PCR, and immunohistochemistry to test whether ceftriaxone treatment preserves intracortical inhibition and cortical parvalbumin-positive inhibitory interneuron function after TBI in rat motor cortex. We show that neocortical GLT-1 gene and protein expression are significantly reduced 1 week after TBI, and this transient loss is mitigated by ceftriaxone. Importantly, whereas intracortical inhibition declines progressively after TBI, 1 week of post-TBI ceftriaxone treatment attenuates the loss of inhibition compared to saline-treated controls. This finding is accompanied by significantly higher parvalbumin gene and protein expression in ceftriaxone-treated injured rats. Our results highlight prospects for ceftriaxone as an intervention after TBI to prevent cortical inhibitory interneuron dysfunction, partly by preserving GLT-1 expression.
Collapse
Affiliation(s)
- Mustafa Q Hameed
- Department of Neurology, Division of Epilepsy and Clinical Neurophysiology, Neuromodulation Program, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
- Department of Neurosurgery, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Tsung-Hsun Hsieh
- Department of Neurology, Division of Epilepsy and Clinical Neurophysiology, Neuromodulation Program, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
- Department of Physical Therapy & Graduate Institute of Rehabilitation Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Neuroscience Research Center, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan, Taiwan
| | - Leon Morales-Quezada
- Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Henry H C Lee
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Ugur Damar
- Department of Neurology, Division of Epilepsy and Clinical Neurophysiology, Neuromodulation Program, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Paul C MacMullin
- Department of Neurology, Division of Epilepsy and Clinical Neurophysiology, Neuromodulation Program, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Takao K Hensch
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
- Department of Molecular & Cellular Biology, Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Alexander Rotenberg
- Department of Neurology, Division of Epilepsy and Clinical Neurophysiology, Neuromodulation Program, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| |
Collapse
|
21
|
Pernici CD, Kemp BS, Murray TA. Time course images of cellular injury and recovery in murine brain with high-resolution GRIN lens system. Sci Rep 2019; 9:7946. [PMID: 31138885 PMCID: PMC6538613 DOI: 10.1038/s41598-019-44174-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 05/10/2019] [Indexed: 12/20/2022] Open
Abstract
Time course, in vivo imaging of brain cells is crucial to fully understand the progression of secondary cellular damage and recovery in murine models of injury. We have combined high-resolution gradient index lens technology with a model of diffuse axonal injury in rodents to enable repeated visualization of fine features of individual cells in three-dimensional space over several weeks. For example, we recorded changes in morphology in the same axons in the external capsule numerous times over 30 to 60 days, before and after induced traumatic brain injury. We observed the expansion of secondary injury and limited recovery of individual axons in this subcortical white matter tract over time. In another application, changes in microglial activation state were visualized in the penumbra region of mice before and after ischemia induced by middle carotid artery occlusion. The ability to collect a series of high-resolution images of cellular features of the same cells pre- and post-injury enables a unique opportunity to study the progression of damage, spontaneous healing, and effects of therapeutics in mouse models of neurodegenerative disease and brain injury.
Collapse
Affiliation(s)
- Chelsea D Pernici
- Center for Biomedical Engineering and Rehabilitation Sciences, Louisiana Tech University, Ruston, Louisiana, USA
| | - Benjamin S Kemp
- Center for Biomedical Engineering and Rehabilitation Sciences, Louisiana Tech University, Ruston, Louisiana, USA
| | - Teresa A Murray
- Center for Biomedical Engineering and Rehabilitation Sciences, Louisiana Tech University, Ruston, Louisiana, USA.
| |
Collapse
|
22
|
Mollayeva T, Hurst M, Escobar M, Colantonio A. Sex-specific incident dementia in patients with central nervous system trauma. ALZHEIMER'S & DEMENTIA: DIAGNOSIS, ASSESSMENT & DISEASE MONITORING 2019; 11:355-367. [PMID: 31065582 PMCID: PMC6495080 DOI: 10.1016/j.dadm.2019.03.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Introduction Despite evidence that central nervous system (CNS) trauma, including traumatic brain injury and spinal cord injury, can cause sustained neurocognitive impairment, it remains unclear whether trauma-related variables are associated with incident dementia independently of other known risk factors. Methods All adults without dementia entering the health-care system with diagnoses of CNS trauma were examined for occurrence of dementia. All trauma-related variables were examined as predictors in sex-specific Cox regression models, controlling for other known risk factors. Results Over a median follow-up of 52 months, 32,834 of 712,708 patients (4.6%) developed dementia. Traumatic brain injury severity and spinal cord injury interacted with age to influence dementia onset; women were at a greater risk of developing dementia earlier than men, all other factors being equal. Discussion Risk stratification of patients with CNS trauma by sex is vital in identifying those most likely to develop dementia and in understanding the course and modifying factors.
Collapse
Affiliation(s)
- Tatyana Mollayeva
- Rehabilitation Sciences Institute, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Toronto Rehab-University Health Network, Toronto, Ontario, Canada.,Acquired Brain Injury Research Lab, University of Toronto, Toronto, Ontario, Canada
| | - Mackenzie Hurst
- Toronto Rehab-University Health Network, Toronto, Ontario, Canada
| | - Michael Escobar
- Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
| | - Angela Colantonio
- Rehabilitation Sciences Institute, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Toronto Rehab-University Health Network, Toronto, Ontario, Canada.,Acquired Brain Injury Research Lab, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|