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Soni ND, Swain A, Juul H, Cao Q, Haris M, Wolk DA, Lee VMY, Detre JA, Nanga RPR, Reddy R. Detection of sex-specific glutamate changes in subregions of hippocampus in an early-stage Alzheimer's disease mouse model using GluCEST MRI. Alzheimers Dement 2024. [PMID: 39262197 DOI: 10.1002/alz.14190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Revised: 07/05/2024] [Accepted: 07/24/2024] [Indexed: 09/13/2024]
Abstract
INTRODUCTION Regional glucose hypometabolism resulting in glutamate loss has been shown as one of the characteristics of Alzheimer's disease (AD). Because the impact of AD varies between the sexes, we utilized glutamate-weighted chemical exchange saturation transfer (GluCEST) magnetic resonance imaging (MRI) for high-resolution spatial mapping of cerebral glutamate and investigated subregional changes in a sex-specific manner. METHODS Eight-month-old male and female AD mice harboring mutant amyloid precursor protein (APPNL-F/NL-F: n = 36) and wild-type (WT: n = 39) mice underwent GluCEST MRI, followed by proton magnetic resonance spectroscopy (1H-MRS) in hippocampus and thalamus/hypothalamus using 9.4T preclinical MR scanner. RESULTS GluCEST measurements revealed significant (p ≤ 0.02) glutamate loss in the entorhinal cortex (% change ± standard error: 8.73 ± 2.12%), hippocampus (11.29 ± 2.41%), and hippocampal fimbriae (19.15 ± 2.95%) of male AD mice. A similar loss of hippocampal glutamate in male AD mice (11.22 ± 2.33%; p = 0.01) was also observed in 1H-MRS. DISCUSSIONS GluCEST MRI detected glutamate reductions in the fimbria and entorhinal cortex of male AD mice, which was not reported previously. Resilience in female AD mice against these changes indicates an intact status of cerebral energy metabolism. HIGHLIGHTS Glutamate levels were monitored in different brain regions of early-stage Alzheimer's disease (AD) and wild-type male and female mice using glutamate-weighted chemical exchange saturation transfer (GluCEST) magnetic resonance imaging (MRI). Male AD mice exhibited significant glutamate loss in the hippocampus, entorhinal cortex, and the fimbriae of the hippocampus. Interestingly, female AD mice did not have any glutamate loss in any brain region and should be investigated further to find the probable cause. These findings demonstrate previously unreported sex-specific glutamate changes in hippocampal sub-regions using high-resolution GluCEST MRI.
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Affiliation(s)
- Narayan Datt Soni
- Department of Radiology, Perelman School of Medicine, Center for Advanced Metabolic Imaging in Precision Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Anshuman Swain
- Department of Radiology, Perelman School of Medicine, Center for Advanced Metabolic Imaging in Precision Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Halvor Juul
- Department of Radiology, Perelman School of Medicine, Center for Advanced Metabolic Imaging in Precision Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Quy Cao
- Department of Biostatistics, Epidemiology, and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Mohammad Haris
- Department of Radiology, Perelman School of Medicine, Center for Advanced Metabolic Imaging in Precision Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - David A Wolk
- Center for Cognitive Neuroscience, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Alzheimer's Disease Research Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Virginia M-Y Lee
- Alzheimer's Disease Research Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Center for Neurodegenerative Disease Research, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - John A Detre
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Ravi Prakash Reddy Nanga
- Department of Radiology, Perelman School of Medicine, Center for Advanced Metabolic Imaging in Precision Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Ravinder Reddy
- Department of Radiology, Perelman School of Medicine, Center for Advanced Metabolic Imaging in Precision Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Shahid SS, Dzemidzic M, Butch ER, Jarvis EE, Snyder SE, Wu YC. Estimating the synaptic density deficit in Alzheimer's disease using multi-contrast CEST imaging. PLoS One 2024; 19:e0299961. [PMID: 38483851 PMCID: PMC10939256 DOI: 10.1371/journal.pone.0299961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 02/12/2024] [Indexed: 03/17/2024] Open
Abstract
In vivo noninvasive imaging of neurometabolites is crucial to improve our understanding of the underlying pathophysiological mechanism in neurodegenerative diseases. Abnormal changes in synaptic organization leading to synaptic degradation and neuronal loss is considered as one of the primary factors driving Alzheimer's disease pathology. Magnetic resonance based molecular imaging techniques such as chemical exchange saturation transfer (CEST) and magnetic resonance spectroscopy (MRS) can provide neurometabolite specific information which may relate to underlying pathological and compensatory mechanisms. In this study, CEST and short echo time single voxel MRS was performed to evaluate the sensitivity of cerebral metabolites to beta-amyloid (Aβ) induced synaptic deficit in the hippocampus of a mouse model of Alzheimer's disease. The CEST based spectra (Z-spectra) were acquired on a 9.4 Tesla small animal MR imaging system with two radiofrequency (RF) saturation amplitudes (1.47 μT and 5.9 μT) to obtain creatine-weighted and glutamate-weighted CEST contrasts, respectively. Multi-pool Lorentzian fitting and quantitative T1 longitudinal relaxation maps were used to obtain metabolic specific apparent exchange-dependent relaxation (AREX) maps. Short echo time (TE = 12 ms) single voxel MRS was acquired to quantify multiple neurometabolites from the right hippocampus region. AREX contrasts and MRS based metabolite concentration levels were examined in the ARTE10 animal model for Alzheimer's disease and their wild type (WT) littermate counterparts (age = 10 months). Using MRS voxel as a region of interest, group-wise analysis showed significant reduction in Glu-AREX and Cr-AREX in ARTE10, compared to WT animals. The MRS based results in the ARTE10 mice showed significant decrease in glutamate (Glu) and glutamate-total creatine (Glu/tCr) ratio, compared to WT animals. The MRS results also showed significant increase in total creatine (tCr), phosphocreatine (PCr) and glutathione (GSH) concentration levels in ARTE10, compared to WT animals. In the same ROI, Glu-AREX and Cr-AREX demonstrated positive associations with Glu/tCr ratio. These results indicate the involvement of neurotransmitter metabolites and energy metabolism in Aβ-mediated synaptic degradation in the hippocampus region. The study also highlights the feasibility of CEST and MRS to identify and track multiple competing and compensatory mechanisms involved in heterogeneous pathophysiology of Alzheimer's disease in vivo.
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Affiliation(s)
- Syed Salman Shahid
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States of America
| | - Mario Dzemidzic
- Department of Neurology, Indiana University School of Medicine, Indianapolis, IN, United States of America
| | - Elizabeth R. Butch
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States of America
| | - Erin E. Jarvis
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States of America
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, United States of America
| | - Scott E. Snyder
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States of America
| | - Yu-Chien Wu
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States of America
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, United States of America
- Weldon School of Biomedical Engineering at Purdue University, West Lafayette, IN, United States of America
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Sidoryk-Węgrzynowicz M, Adamiak K, Strużyńska L. Astrocyte-Neuron Interaction via the Glutamate-Glutamine Cycle and Its Dysfunction in Tau-Dependent Neurodegeneration. Int J Mol Sci 2024; 25:3050. [PMID: 38474295 DOI: 10.3390/ijms25053050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 02/26/2024] [Accepted: 03/01/2024] [Indexed: 03/14/2024] Open
Abstract
Astroglia constitute the largest group of glial cells and are involved in numerous actions that are critical to neuronal development and functioning, such as maintaining the blood-brain barrier, forming synapses, supporting neurons with nutrients and trophic factors, and protecting them from injury. These properties are deeply affected in the course of many neurodegenerative diseases, including tauopathies, often before the onset of the disease. In this respect, the transfer of essential amino acids such as glutamate and glutamine between neurons and astrocytes in the glutamate-glutamine cycle (GGC) is one example. In this review, we focus on the GGC and the disruption of this cycle in tau-dependent neurodegeneration. A profound understanding of the complex functions of the GGC and, in the broader context, searching for dysfunctions in communication pathways between astrocytes and neurons via GGC in health and disease, is of critical significance for the development of novel mechanism-based therapies for neurodegenerative disorders.
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Affiliation(s)
- Marta Sidoryk-Węgrzynowicz
- Laboratory of Pathoneurochemistry, Department of Neurochemistry, Mossakowski Medical Research Institute, Polish Academy of Sciences, 5 Pawińskiego Str., 02-106 Warsaw, Poland
| | - Kamil Adamiak
- Laboratory of Pathoneurochemistry, Department of Neurochemistry, Mossakowski Medical Research Institute, Polish Academy of Sciences, 5 Pawińskiego Str., 02-106 Warsaw, Poland
| | - Lidia Strużyńska
- Laboratory of Pathoneurochemistry, Department of Neurochemistry, Mossakowski Medical Research Institute, Polish Academy of Sciences, 5 Pawińskiego Str., 02-106 Warsaw, Poland
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Tsai YC, Huang SM, Peng HH, Lin SW, Lin SR, Chin TY, Huang SM. Imbalance of synaptic and extrasynaptic NMDA receptors induced by the deletion of CRMP1 accelerates age-related cognitive decline in mice. Neurobiol Aging 2024; 135:48-59. [PMID: 38176125 DOI: 10.1016/j.neurobiolaging.2023.12.006] [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: 07/04/2023] [Revised: 12/25/2023] [Accepted: 12/27/2023] [Indexed: 01/06/2024]
Abstract
Collapsin response mediator protein 1 (CRMP1) is involved in semaphorin 3A signaling pathway, promoting neurite extension and growth cone collapse. It is highly expressed in the nervous system, especially the hippocampus. The crmp1 knockout (KO) mice display impaired spatial learning and memory, and this phenomenon seemingly tends to deteriorate with age. Here we investigated whether CRMP1 is involved in age-related cognitive decline in WT and crmp1 KO mice at adult, middle-aged and older stages. The results revealed that cognitive dysfunction in the Morris water maze task became more severe and decreased glutamate and glutamine level in middle-aged crmp1 KO mice. Additionally, increasing levels of extrasynaptic NMDA receptors and phosphorylation of Tau were observed in middle-aged crmp1 KO mice, leading to synaptic and neuronal loss in the CA3 regions of hippocampus. These findings suggest that deletion of CRMP1 accelerates age-related cognitive decline by disrupting the balance between synaptic and extrasynaptic NMDA receptors, resulting in the loss of synapses and neurons.
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Affiliation(s)
- Yun-Chieh Tsai
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
| | - Sheng-Min Huang
- Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, Miaoli, Taiwan
| | - Hsu-Hsia Peng
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan
| | - Shu-Wha Lin
- Department of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Shu-Rung Lin
- Department of Bioscience Technology, Chung Yuan Christian University, Taoyuan, Taiwan.
| | - Ting-Yu Chin
- Department of Bioscience Technology, Chung Yuan Christian University, Taoyuan, Taiwan.
| | - Shih-Ming Huang
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan; Department of Biochemistry, National Defense Medical Center, Taipei, Taiwan.
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Viswanathan M, Kurmi Y, Zu Z. Nuclear Overhauser enhancement imaging at -1.6 ppm in rat brain at 4.7T. Magn Reson Med 2024; 91:615-629. [PMID: 37867419 DOI: 10.1002/mrm.29896] [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: 06/12/2023] [Revised: 09/21/2023] [Accepted: 10/04/2023] [Indexed: 10/24/2023]
Abstract
PURPOSE A new nuclear Overhauser enhancement (NOE)-mediated saturation transfer signal at around -1.6 ppm, termed NOE(-1.6), has been reported at high fields of 7T and 9.4T previously. This study aims to validate the presence of this signal at a relatively low field of 4.7T and evaluate its variations in different brain regions and tumors. METHODS Rats were injected with monocrystalline iron oxide nanoparticles to reduce the NOE(-1.6) signal. CEST signals were measured using different saturation powers before and after injection to assess the presence of this signal. Multiple-pool Lorentzian fits, with/without inclusion of the NOE(-1.6) pool, were performed on CEST Z-spectra obtained from healthy rat brains and rats with 9L tumors. These fits aimed to further validate the presence of the NOE(-1.6) signal and quantify its amplitude. RESULTS The NOE(-1.6) signal exhibited a dramatic change following the injection of monocrystalline iron oxide nanoparticles, confirming its presence at 4.7T. The NOE(-1.6) signal reached its peak at a saturation power of ∼0.75 μT, indicating an optimized power level. The multiple-pool Lorentzian fit without the NOE(-1.6) pool showed higher residuals around -1.6 ppm compared to the fit with this pool, further supporting the presence of this signal. The NOE(-1.6) signal did not exhibit significant variation in the corpus callosum and caudate putamen regions, but it showed a significant decrease in tumors, which aligns with previous findings at 9.4T. CONCLUSION This study successfully demonstrated the presence of the NOE(-1.6) signal at 4.7T, which provides valuable insights into its potential applications at lower field strengths.
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Affiliation(s)
- Malvika Viswanathan
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA
| | - Yashwant Kurmi
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Zhongliang Zu
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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Perera Molligoda Arachchige AS, Garner AK. Seven Tesla MRI in Alzheimer's disease research: State of the art and future directions: A narrative review. AIMS Neurosci 2023; 10:401-422. [PMID: 38188012 PMCID: PMC10767068 DOI: 10.3934/neuroscience.2023030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 11/29/2023] [Accepted: 12/04/2023] [Indexed: 01/09/2024] Open
Abstract
Seven tesla magnetic resonance imaging (7T MRI) is known to offer a superior spatial resolution and a signal-to-noise ratio relative to any other non-invasive imaging technique and provides the possibility for neuroimaging researchers to observe disease-related structural changes, which were previously only apparent on post-mortem tissue analyses. Alzheimer's disease is a natural and widely used subject for this technology since the 7T MRI allows for the anticipation of disease progression, the evaluation of secondary prevention measures thought to modify the disease trajectory, and the identification of surrogate markers for treatment outcome. In this editorial, we discuss the various neuroimaging biomarkers for Alzheimer's disease that have been studied using 7T MRI, which include morphological alterations, molecular characterization of cerebral T2*-weighted hypointensities, the evaluation of cerebral microbleeds and microinfarcts, biochemical changes studied with MR spectroscopy, as well as some other approaches. Finally, we discuss the limitations of the 7T MRI regarding imaging Alzheimer's disease and we provide our outlook for the future.
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7
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Sidoryk-Węgrzynowicz M, Dąbrowska-Bouta B, Sulkowski G, Strużyńska L. Mutant Tau protein-induced abnormalities in the Na +-dependent glutamine translocation and recycling and their impact on astrocyte-neuron integrity in vitro. Neurochem Int 2023; 168:105551. [PMID: 37295680 DOI: 10.1016/j.neuint.2023.105551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 05/15/2023] [Accepted: 05/22/2023] [Indexed: 06/12/2023]
Abstract
Tau-dependent neurodegeneration is accompanied by astrocytosis in a mouse trans-genic model, which replicates the neuropathological characteristic of tauopathy and other human neurodegenerative disorders where astrocyte activation precedes neuronal loss and is associated with disease progression. This indicates an important role of astrocytes in the development of the disease. Astrocytes derived from a transgenic mouse model expressing human Tau, exhibit changes in cellular markers of astrocyte neuroprotective function related to the glutamate-glutamine cycle (GGC), representing a key part of astrocyte-neuron integrity. Here, we focused on investigating the functional properties of key GGC components involved in the astrocyte-neuron network associated with Tau pathology in vitro. Mutant recombinant Tau (rTau) carrying the P301L mutation was added to the neuronal cultures, with or without control astrocyte-conditioned medium (ACM), to study glutamine translocation through the GGC. We demonstrated that mutant Tau in vitro induces neuronal degeneration, while control astrocytes response in neuroprotective way by preventing neurodegeneration. In parallel with this observation, we noticed the Tau-dependent decline of neuronal microtubule associated protein 2 (MAP2), followed by changes in glutamine (Gln) transport. Exposure to rTau decreases sodium-dependent Gln uptake in neurons and that effect was reversed when cells were co-incubated with control ACM after induction of rTau dependent pathology. Further, we found that neuronal Na+-dependent system A is the most specific system that is affected under rTau exposure. In addition, in rTau-treated astrocytes total Na+-dependent uptake of Gln, which is mediated by the N system, increases. Altogether, our study suggest mechanisms operating in Tau pathology may be related to the alterations in glutamine transport and recycling that affect neuronal-astrocytic integrity.
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Affiliation(s)
- Marta Sidoryk-Węgrzynowicz
- Laboratory of Pathoneurochemistry, Department of Neurochemistry, Mossakowski Medical Research Institute, Polish Academy of Sciences, 5 Pawińskiego str, 02-106, Warsaw, Poland.
| | - Beata Dąbrowska-Bouta
- Laboratory of Pathoneurochemistry, Department of Neurochemistry, Mossakowski Medical Research Institute, Polish Academy of Sciences, 5 Pawińskiego str, 02-106, Warsaw, Poland
| | - Grzegorz Sulkowski
- Laboratory of Pathoneurochemistry, Department of Neurochemistry, Mossakowski Medical Research Institute, Polish Academy of Sciences, 5 Pawińskiego str, 02-106, Warsaw, Poland
| | - Lidia Strużyńska
- Laboratory of Pathoneurochemistry, Department of Neurochemistry, Mossakowski Medical Research Institute, Polish Academy of Sciences, 5 Pawińskiego str, 02-106, Warsaw, Poland
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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.
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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
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Perez-Garcia G, Bicak M, Haure-Mirande JV, Perez GM, Otero-Pagan A, Gama Sosa MA, De Gasperi R, Sano M, Barlow C, Gage FH, Readhead B, Ehrlich ME, Gandy S, Elder GA. BCI-838, an orally active mGluR2/3 receptor antagonist pro-drug, rescues learning behavior deficits in the PS19 MAPT P301S mouse model of tauopathy. Neurosci Lett 2023; 797:137080. [PMID: 36657633 PMCID: PMC9974759 DOI: 10.1016/j.neulet.2023.137080] [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: 11/27/2022] [Revised: 01/04/2023] [Accepted: 01/12/2023] [Indexed: 01/18/2023]
Abstract
Tauopathies are a heterogeneous group of neurodegenerative disorders that are clinically and pathologically distinct from Alzheimer's disease (AD) having tau inclusions in neurons and/or glia as their most prominent neuropathological feature. BCI-838 (MGS00210) is a group II metabotropic glutamate receptor (mGluR2/3) antagonist pro-drug. Previously, we reported that orally administered BCI-838 improved learning behavior and reduced anxiety in Dutch (APPE693Q) transgenic mice, a model of the pathological accumulation of Aβ oligomers found in AD. Herein, we investigated effects of BCI-838 on PS19 male mice that express the tauopathy mutation MAPTP301S associated with human frontotemporal lobar degeneration (FTLD). These mice develop an aging-related tauopathy without amyloid accumulation. Mice were divided into three experimental groups: (1) non-transgenic wild type mice treated with vehicle, (2) PS19 mice treated with vehicle and (3) PS19 mice treated with 5 mg/kg BCI-838. Groups of 10-13 mice were utilized. Vehicle or BCI-838 was administered by oral gavage for 4 weeks. Behavioral testing consisting of a novel object recognition task was conducted after drug administration. Two studies were performed beginning treatment of mice at 3 or 7 months of age. One month of BCI-838 treatment rescued deficits in recognition memory in PS19 mice whether treatment was begun at 3 or 7 months of age. These studies extend the potential utility of BCI-838 to neurodegenerative conditions that have tauopathy as their underlying basis. They also suggest an mGluR2/3 dependent mechanism as a basis for the behavioral deficits in PS19 mice.
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Affiliation(s)
- Georgina Perez-Garcia
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Research and Development, James J. Peters Veterans Affairs Medical Center, Bronx, NY 10468, USA
| | - Mesude Bicak
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Hasso Plattner Institute for Digital Health at Mount Sinai, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | | | - Gissel M Perez
- Research and Development, James J. Peters Veterans Affairs Medical Center, Bronx, NY 10468, USA
| | - Alena Otero-Pagan
- Research and Development, James J. Peters Veterans Affairs Medical Center, Bronx, NY 10468, USA
| | - Miguel A Gama Sosa
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; General Medical Research Service, James J. Peters Department of Veterans Affairs Medical Center, Bronx, NY 10468, USA
| | - Rita De Gasperi
- Research and Development, James J. Peters Veterans Affairs Medical Center, Bronx, NY 10468, USA; Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Mary Sano
- Research and Development, James J. Peters Veterans Affairs Medical Center, Bronx, NY 10468, USA; Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Mount Sinai Alzheimer's Disease Research Center and Ronald M. Loeb Center for Alzheimer's Disease, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Carrolee Barlow
- BrainCells Inc., La Jolla, CA 92037, USA; EScape Bio, South San Francisco, CA 94080, USA
| | - Fred H Gage
- BrainCells Inc., La Jolla, CA 92037, USA; Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Benjamin Readhead
- Arizona State University-Banner Neurodegenerative Disease Research Center, Arizona State University, Tempe, AZ 85287, USA
| | - Michelle E Ehrlich
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Sam Gandy
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Research and Development, James J. Peters Veterans Affairs Medical Center, Bronx, NY 10468, USA; Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Mount Sinai Alzheimer's Disease Research Center and Ronald M. Loeb Center for Alzheimer's Disease, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Mount Sinai Center for Cognitive Health, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Gregory A Elder
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Mount Sinai Alzheimer's Disease Research Center and Ronald M. Loeb Center for Alzheimer's Disease, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Neurology Service, James J. Peters Veterans Affairs Medical Center, Bronx, NY 10468, USA.
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Cui J, Sun C, Zu Z. NOE-weighted imaging in tumors using low-duty-cycle 2π-CEST. Magn Reson Med 2023; 89:636-651. [PMID: 36198015 PMCID: PMC9792266 DOI: 10.1002/mrm.29475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 08/19/2022] [Accepted: 09/12/2022] [Indexed: 02/03/2023]
Abstract
PURPOSE Nuclear Overhauser enhancement (NOE)-mediated CEST imaging at -3.5 ppm has shown clinical interest in diagnosing tumors. Multiple-pool Lorentzian fit has been used to quantify NOE, which, however, requires a long scan time. Asymmetric analysis of CEST signals could be a simple and fast method to quantify this NOE, but it has contamination from the amide proton transfer (APT) at 3.5 ppm. This work proposes a new method using an asymmetric analysis of a low-duty-cycle pulsed-CEST sequence with a flip angle of 360°, termed 2π-CEST, to reduce the contribution from APT. METHODS Simulations were used to evaluate the capability of the 2π-CEST to reduce APT. Experiments on animal tumor models were performed to show its advantages compared with the conventional asymmetric analysis. Samples of reconstituted phospholipids and proteins were used to evaluate the molecular origin of this NOE. RESULTS The 2π-CEST has reduced contribution from APT. In tumors where we show that the NOE is comparable to the APT effect, reducing the contamination from APT is crucial. The results show that the NOE signal obtained with 2π-CEST in tumor regions appears more homogeneous than that obtained with the conventional method. The phantom study showed that both phospholipids and proteins contribute to the NOE at -3.5 ppm. CONCLUSION The NOE at -3.5 ppm has a different contrast mechanism from APT and other CEST/NOE effects. The proposed 2π-CEST is more accurate than the conventional asymmetric analysis in detecting NOE, and requires much less scan time than the multiple-pool Lorentzian fit.
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Affiliation(s)
- Jing Cui
- Vanderbilt University Institute of Imaging Science, Nashville, US,Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, US
| | - Casey Sun
- Vanderbilt University Institute of Imaging Science, Nashville, US,Department of Chemistry, University of Florida, Gainesville, US
| | - Zhongliang Zu
- Vanderbilt University Institute of Imaging Science, Nashville, US,Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, US
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11
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Cox MF, Hascup ER, Bartke A, Hascup KN. Friend or Foe? Defining the Role of Glutamate in Aging and Alzheimer’s Disease. FRONTIERS IN AGING 2022; 3:929474. [PMID: 35821835 PMCID: PMC9261322 DOI: 10.3389/fragi.2022.929474] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 05/17/2022] [Indexed: 11/13/2022]
Abstract
Aging is a naturally occurring decline of physiological processes and biological pathways that affects both the structural and functional integrity of the body and brain. These physiological changes reduce motor skills, executive function, memory recall, and processing speeds. Aging is also a major risk factor for multiple neurodegenerative disorders including Alzheimer’s disease (AD). Identifying a biomarker, or biomarkers, that signals the transition from physiological to pathological aging would aid in earlier therapeutic options or interventional strategies. Considering the importance of glutamate signaling in synaptic plasticity, motor movement, and cognition, this neurotransmitter serves as a juncture between cognitive health and disease. This article discusses glutamatergic signaling during physiological aging and the pathological changes observed in AD patients. Findings from studies in mouse models of successful aging and AD are reviewed and provide a biological context for this transition. Finally, current techniques to monitor brain glutamate are highlighted. These techniques may aid in elucidating time-point specific therapeutic windows to modify disease outcome.
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Affiliation(s)
- MaKayla F. Cox
- Dale and Deborah Smith Center for Alzheimer’s Research and Treatment, Department of Neurology, Neurosciences Institute, Southern Illinois University School of Medicine, Springfield, IL, United States
| | - Erin R. Hascup
- Dale and Deborah Smith Center for Alzheimer’s Research and Treatment, Department of Neurology, Neurosciences Institute, Southern Illinois University School of Medicine, Springfield, IL, United States
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL, United States
| | - Andrzej Bartke
- Dale and Deborah Smith Center for Alzheimer’s Research and Treatment, Department of Neurology, Neurosciences Institute, Southern Illinois University School of Medicine, Springfield, IL, United States
- Department of Internal Medicine, Southern Illinois University School of Medicine, Springfield, IL, United States
- Department of Medical Microbiology, Immunology and Cell Biology, Southern Illinois University School of Medicine, Springfield, IL, United States
| | - Kevin N. Hascup
- Dale and Deborah Smith Center for Alzheimer’s Research and Treatment, Department of Neurology, Neurosciences Institute, Southern Illinois University School of Medicine, Springfield, IL, United States
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL, United States
- Department of Medical Microbiology, Immunology and Cell Biology, Southern Illinois University School of Medicine, Springfield, IL, United States
- *Correspondence: Kevin N. Hascup,
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12
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Serrano ME, Kim E, Petrinovic MM, Turkheimer F, Cash D. Imaging Synaptic Density: The Next Holy Grail of Neuroscience? Front Neurosci 2022; 16:796129. [PMID: 35401097 PMCID: PMC8990757 DOI: 10.3389/fnins.2022.796129] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 02/15/2022] [Indexed: 12/19/2022] Open
Abstract
The brain is the central and most complex organ in the nervous system, comprising billions of neurons that constantly communicate through trillions of connections called synapses. Despite being formed mainly during prenatal and early postnatal development, synapses are continually refined and eliminated throughout life via complicated and hitherto incompletely understood mechanisms. Failure to correctly regulate the numbers and distribution of synapses has been associated with many neurological and psychiatric disorders, including autism, epilepsy, Alzheimer’s disease, and schizophrenia. Therefore, measurements of brain synaptic density, as well as early detection of synaptic dysfunction, are essential for understanding normal and abnormal brain development. To date, multiple synaptic density markers have been proposed and investigated in experimental models of brain disorders. The majority of the gold standard methodologies (e.g., electron microscopy or immunohistochemistry) visualize synapses or measure changes in pre- and postsynaptic proteins ex vivo. However, the invasive nature of these classic methodologies precludes their use in living organisms. The recent development of positron emission tomography (PET) tracers [such as (18F)UCB-H or (11C)UCB-J] that bind to a putative synaptic density marker, the synaptic vesicle 2A (SV2A) protein, is heralding a likely paradigm shift in detecting synaptic alterations in patients. Despite their limited specificity, novel, non-invasive magnetic resonance (MR)-based methods also show promise in inferring synaptic information by linking to glutamate neurotransmission. Although promising, all these methods entail various advantages and limitations that must be addressed before becoming part of routine clinical practice. In this review, we summarize and discuss current ex vivo and in vivo methods of quantifying synaptic density, including an evaluation of their reliability and experimental utility. We conclude with a critical assessment of challenges that need to be overcome before successfully employing synaptic density biomarkers as diagnostic and/or prognostic tools in the study of neurological and neuropsychiatric disorders.
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Affiliation(s)
- Maria Elisa Serrano
- Department of Neuroimaging, The BRAIN Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom.,Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, London, United Kingdom
| | - Eugene Kim
- Department of Neuroimaging, The BRAIN Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom.,Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, London, United Kingdom
| | - Marija M Petrinovic
- Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom.,MRC Centre for Neurodevelopmental Disorders, King's College London, London, United Kingdom
| | - Federico Turkheimer
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, London, United Kingdom
| | - Diana Cash
- Department of Neuroimaging, The BRAIN Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom.,Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, London, United Kingdom
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13
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Cember ATJ, Deck BL, Kelkar A, Faseyitan O, Zimmerman JP, Erickson B, Elliott MA, Coslett HB, Hamilton RH, Reddy R, Medaglia JD. Glutamate-Weighted Magnetic Resonance Imaging (GluCEST) Detects Effects of Transcranial Magnetic Stimulation to the Motor Cortex. Neuroimage 2022; 256:119191. [PMID: 35413447 DOI: 10.1016/j.neuroimage.2022.119191] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Revised: 03/18/2022] [Accepted: 04/05/2022] [Indexed: 11/18/2022] Open
Abstract
Transcranial magnetic stimulation (TMS) is used in several FDA-approved treatments and, increasingly, to treat neurological disorders in off-label uses. However, the mechanism by which TMS causes physiological change is unclear, as are the origins of response variability in the general population. Ideally, objective in vivo biomarkers could shed light on these unknowns and eventually inform personalized interventions. Continuous theta-burst stimulation (cTBS) is a form of TMS observed to reduce motor evoked potentials (MEPs) for 60 min or longer post-stimulation, although the consistency of this effect and its mechanism continue to be under debate. Here, we use glutamate-weighted chemical exchange saturation transfer (gluCEST) magnetic resonance imaging (MRI) at ultra-high magnetic field (7T) to measure changes in glutamate concentration at the site of cTBS. We find that the gluCEST signal in the ipsilateral hemisphere of the brain generally decreases in response to cTBS, whereas consistent changes were not detected in the contralateral region of interest (ROI) or in subjects receiving sham stimulation.
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Affiliation(s)
- Abigail T J Cember
- Center for Advanced Metabolic Imaging in Precision Medicine, Department of Radiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA.
| | - Benjamin L Deck
- Department of Psychological and Brain Sciences, Drexel University, Philadelphia, PA, USA
| | - Apoorva Kelkar
- Department of Psychological and Brain Sciences, Drexel University, Philadelphia, PA, USA
| | - Olu Faseyitan
- Department of Neurology, Laboratory for Cognition and Neural Stimulation, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Jared P Zimmerman
- Department of Neurology, Laboratory for Cognition and Neural Stimulation, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Brian Erickson
- Department of Psychological and Brain Sciences, Drexel University, Philadelphia, PA, USA
| | - Mark A Elliott
- Center for Advanced Metabolic Imaging in Precision Medicine, Department of Radiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - H Branch Coslett
- Department of Neurology, Laboratory for Cognition and Neural Stimulation, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Roy H Hamilton
- Department of Neurology, Laboratory for Cognition and Neural Stimulation, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Ravinder Reddy
- Center for Advanced Metabolic Imaging in Precision Medicine, Department of Radiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - John D Medaglia
- Department of Psychological and Brain Sciences, Drexel University, Philadelphia, PA, USA; Department of Neurology, Laboratory for Cognition and Neural Stimulation, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
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14
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O'Grady KP, Satish S, Owen QR, Box BA, Bagnato F, Combes AJE, Cook SR, Westervelt HJ, Feiler HR, Lawless RD, Sarma A, Malone SD, Ndolo JM, Yoon K, Dortch RD, Rogers BP, Smith SA. Relaxation-Compensated Chemical Exchange Saturation Transfer MRI in the Brain at 7T: Application in Relapsing-Remitting Multiple Sclerosis. Front Neurol 2022; 13:764690. [PMID: 35299614 PMCID: PMC8923037 DOI: 10.3389/fneur.2022.764690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 02/01/2022] [Indexed: 11/16/2022] Open
Abstract
Chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI) can probe tissue biochemistry in vivo with high resolution and sensitivity without requiring exogenous contrast agents. Applying CEST MRI at ultrahigh field provides advantages of increasing spectral resolution and improving sensitivity to metabolites with faster proton exchange rates such as glutamate, a critical neurotransmitter in the brain. Prior magnetic resonance spectroscopy and CEST MRI studies have revealed altered regulation of glutamate in patients with multiple sclerosis (MS). While CEST imaging facilitates new strategies for investigating the pathology underlying this complex and heterogeneous neurological disease, CEST signals are contaminated or diluted by concurrent effects (e.g., semi-solid magnetization transfer (MT) and direct water saturation) and are scaled by the T1 relaxation time of the free water pool which may also be altered in the context of disease. In this study of 20 relapsing-remitting MS patients and age- and sex-matched healthy volunteers, glutamate-weighted CEST data were acquired at 7.0 T. A Lorentzian fitting procedure was used to remove the asymmetric MT contribution from CEST z-spectra, and the apparent exchange-dependent relaxation (AREX) correction was applied using an R1 map derived from an inversion recovery sequence to further isolate glutamate-weighted CEST signals from concurrent effects. Associations between AREX and cognitive function were examined using the Minimal Assessment of Cognitive Function in MS battery. After isolating CEST effects from MT, direct water saturation, and T1 effects, glutamate-weighted AREX contrast remained higher in gray matter than in white matter, though the difference between these tissues decreased. Glutamate-weighted AREX in normal-appearing gray and white matter in MS patients did not differ from healthy gray and white matter but was significantly elevated in white matter lesions. AREX in some cortical regions and in white matter lesions correlated with disability and measures of cognitive function in MS patients. However, further studies with larger sample sizes are needed to confirm these relationships due to potential confounding effects. The application of MT and AREX corrections in this study demonstrates the importance of isolating CEST signals for more specific characterization of the contribution of metabolic changes to tissue pathology and symptoms in MS.
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Affiliation(s)
- Kristin P. O'Grady
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Sanjana Satish
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Quinn R. Owen
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Bailey A. Box
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Francesca Bagnato
- Neuroimaging Unit, Division of Neuroimmunology, Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, United States
- Department of Neurology, Nashville VA Medical Center, TN Valley Healthcare System, Nashville, TN, United States
| | - Anna J. E. Combes
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Sarah R. Cook
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Holly James Westervelt
- Division of Behavioral and Cognitive Neurology, Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Haley R. Feiler
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Richard D. Lawless
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Asha Sarma
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Shekinah D. Malone
- School of Medicine, Meharry Medical College, Nashville, TN, United States
| | - Josephine M. Ndolo
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Keejin Yoon
- Neuroimaging Unit, Division of Neuroimmunology, Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Richard D. Dortch
- Department of Translational Neuroscience, Barrow Neurological Institute, Phoenix, AZ, United States
| | - Baxter P. Rogers
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN, United States
- Biomedical Engineering, Vanderbilt University, Nashville, TN, United States
| | - Seth A. Smith
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States
- Biomedical Engineering, Vanderbilt University, Nashville, TN, United States
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15
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Ni R. Magnetic Resonance Imaging in Tauopathy Animal Models. Front Aging Neurosci 2022; 13:791679. [PMID: 35145392 PMCID: PMC8821905 DOI: 10.3389/fnagi.2021.791679] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 12/27/2021] [Indexed: 11/13/2022] Open
Abstract
The microtubule-associated protein tau plays an important role in tauopathic diseases such as Alzheimer's disease and primary tauopathies such as progressive supranuclear palsy and corticobasal degeneration. Tauopathy animal models, such as transgenic, knock-in mouse and rat models, recapitulating tauopathy have facilitated the understanding of disease mechanisms. Aberrant accumulation of hyperphosphorylated tau contributes to synaptic deficits, neuroinflammation, and neurodegeneration, leading to cognitive impairment in animal models. Recent advances in molecular imaging using positron emission tomography (PET) and magnetic resonance imaging (MRI) have provided valuable insights into the time course of disease pathophysiology in tauopathy animal models. High-field MRI has been applied for in vivo imaging in animal models of tauopathy, including diffusion tensor imaging for white matter integrity, arterial spin labeling for cerebral blood flow, resting-state functional MRI for functional connectivity, volumetric MRI for neurodegeneration, and MR spectroscopy. In addition, MR contrast agents for non-invasive imaging of tau have been developed recently. Many preclinical MRI indicators offer excellent translational value and provide a blueprint for clinical MRI in the brains of patients with tauopathies. In this review, we summarized the recent advances in using MRI to visualize the pathophysiology of tauopathy in small animals. We discussed the outstanding challenges in brain imaging using MRI in small animals and propose a future outlook for visualizing tau-related alterations in the brains of animal models.
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Affiliation(s)
- Ruiqing Ni
- Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland
- Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland
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16
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Takado Y, Takuwa H, Sampei K, Urushihata T, Takahashi M, Shimojo M, Uchida S, Nitta N, Shibata S, Nagashima K, Ochi Y, Ono M, Maeda J, Tomita Y, Sahara N, Near J, Aoki I, Shibata K, Higuchi M. MRS-measured glutamate versus GABA reflects excitatory versus inhibitory neural activities in awake mice. J Cereb Blood Flow Metab 2022; 42:197-212. [PMID: 34515548 PMCID: PMC8721779 DOI: 10.1177/0271678x211045449] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
To assess if magnetic resonance spectroscopy (MRS)-measured Glutamate (Glu) and GABA reflect excitatory and inhibitory neural activities, respectively, we conducted MRS measurements along with two-photon mesoscopic imaging of calcium signals in excitatory and inhibitory neurons of living, unanesthetized mice. For monitoring stimulus-driven activations of a brain region, MRS signals and mesoscopic neural activities were measured during two consecutive sessions of 15-min prolonged sensory stimulations. In the first session, putative excitatory neuronal activities were increased, while inhibitory neuronal activities remained at the baseline level. In the second half, while excitatory neuronal activities remained elevated, inhibitory neuronal activities were significantly enhanced. We assessed regional neurochemical statuses by measuring MRS signals, which were overall in accordance with the neural activities, and neuronal activities and neurochemical statuses in a mouse model of Dravet syndrome under resting condition. Mesoscopic assessments showed that activities of inhibitory neurons in the cortex were diminished relative to wild-type mice in contrast to spared activities of excitatory neurons. Consistent with these observations, the Dravet model exhibited lower concentrations of GABA than wild-type controls. Collectively, the current investigations demonstrate that MRS-measured Glu and GABA can reflect spontaneous and stimulated activities of neurons producing and releasing these neurotransmitters in an awake condition.
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Affiliation(s)
- Yuhei Takado
- Department of Functional Brain Imaging, Institute of Quantum Medical Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
- Yuhei Takado, Department of Functional Brain Imaging, Institute of Quantum Medical Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan.
| | - Hiroyuki Takuwa
- Department of Functional Brain Imaging, Institute of Quantum Medical Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
- Hiroyuki Takuwa, Department of Functional Brain Imaging, Institute of Quantum Medical Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan.
| | - Kazuaki Sampei
- Department of Functional Brain Imaging, Institute of Quantum Medical Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Takuya Urushihata
- Department of Functional Brain Imaging, Institute of Quantum Medical Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Manami Takahashi
- Department of Functional Brain Imaging, Institute of Quantum Medical Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Masafumi Shimojo
- Department of Functional Brain Imaging, Institute of Quantum Medical Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Shoko Uchida
- Department of Functional Brain Imaging, Institute of Quantum Medical Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Nobuhiro Nitta
- Department of Molecular Imaging and Theranostics, Institute of Quantum Medical Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Sayaka Shibata
- Department of Molecular Imaging and Theranostics, Institute of Quantum Medical Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Keisuke Nagashima
- Kansai Photon Science Institute, National Institutes for Quantum and Radiological Science and Technology, Kyoto, Japan
| | - Yoshihiro Ochi
- Kansai Photon Science Institute, National Institutes for Quantum and Radiological Science and Technology, Kyoto, Japan
| | - Maiko Ono
- Department of Functional Brain Imaging, Institute of Quantum Medical Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Jun Maeda
- Department of Functional Brain Imaging, Institute of Quantum Medical Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Yutaka Tomita
- Department of Neurology, Keio University School of Medicine, Tokyo, Japan
| | - Naruhiko Sahara
- Department of Functional Brain Imaging, Institute of Quantum Medical Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Jamie Near
- Douglas Mental Health University Institute and Department of Psychiatry, McGill University, Montreal, Canada
| | - Ichio Aoki
- Department of Molecular Imaging and Theranostics, Institute of Quantum Medical Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Kazuhisa Shibata
- Department of Functional Brain Imaging, Institute of Quantum Medical Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
- Laboratory for Human Cognition and Learning, Center for Brain Science, RIKEN, Saitama, Japan
| | - Makoto Higuchi
- Department of Functional Brain Imaging, Institute of Quantum Medical Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
- Makoto Higuchi, Department of Functional Brain Imaging, Institute of Quantum Medical Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan.
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17
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Orzyłowska A, Oakden W. Saturation Transfer MRI for Detection of Metabolic and Microstructural Impairments Underlying Neurodegeneration in Alzheimer's Disease. Brain Sci 2021; 12:53. [PMID: 35053797 PMCID: PMC8773856 DOI: 10.3390/brainsci12010053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 12/21/2021] [Accepted: 12/25/2021] [Indexed: 01/08/2023] Open
Abstract
Alzheimer's disease (AD) is one of the most common causes of dementia and difficult to study as the pool of subjects is highly heterogeneous. Saturation transfer (ST) magnetic resonance imaging (MRI) methods are quantitative modalities with potential for non-invasive identification and tracking of various aspects of AD pathology. In this review we cover ST-MRI studies in both humans and animal models of AD over the past 20 years. A number of magnetization transfer (MT) studies have shown promising results in human brain. Increased computing power enables more quantitative MT studies, while access to higher magnetic fields improves the specificity of chemical exchange saturation transfer (CEST) techniques. While much work remains to be done, results so far are very encouraging. MT is sensitive to patterns of AD-related pathological changes, improving differential diagnosis, and CEST is sensitive to particular pathological processes which could greatly assist in the development and monitoring of therapeutic treatments of this currently incurable disease.
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Affiliation(s)
- Anna Orzyłowska
- Department of Neurosurgery and Paediatric Neurosurgery, Medical University of Lublin, Jaczewskiego 8 (SPSK 4), 20-090 Lublin, Poland
| | - Wendy Oakden
- Physical Sciences, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON M4N 3M5, Canada;
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18
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Genetic variations influence brain changes in patients with attention-deficit hyperactivity disorder. Transl Psychiatry 2021; 11:349. [PMID: 34091591 PMCID: PMC8179928 DOI: 10.1038/s41398-021-01473-w] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Revised: 05/04/2021] [Accepted: 05/12/2021] [Indexed: 12/12/2022] Open
Abstract
Attention-deficit hyperactivity disorder (ADHD) is a neurological and neurodevelopmental childhood-onset disorder characterized by a persistent pattern of inattentiveness, impulsiveness, restlessness, and hyperactivity. These symptoms may continue in 55-66% of cases from childhood into adulthood. Even though the precise etiology of ADHD is not fully understood, it is considered as a multifactorial and heterogeneous disorder with several contributing factors such as heritability, auxiliary to neurodevelopmental issues, severe brain injuries, neuroinflammation, consanguineous marriages, premature birth, and exposure to environmental toxins. Neuroimaging and neurodevelopmental assessments may help to explore the possible role of genetic variations on ADHD neuropsychobiology. Multiple genetic studies have observed a strong genetic association with various aspects of neuropsychobiological functions, including neural abnormalities and delayed neurodevelopment in ADHD. The advancement in neuroimaging and molecular genomics offers the opportunity to analyze the impact of genetic variations alongside its dysregulated pathways on structural and functional derived brain imaging phenotypes in various neurological and psychiatric disorders, including ADHD. Recently, neuroimaging genomic studies observed a significant association of brain imaging phenotypes with genetic susceptibility in ADHD. Integrating the neuroimaging-derived phenotypes with genomics deciphers various neurobiological pathways that can be leveraged for the development of novel clinical biomarkers, new treatment modalities as well as therapeutic interventions for ADHD patients. In this review, we discuss the neurobiology of ADHD with particular emphasis on structural and functional changes in the ADHD brain and their interactions with complex genomic variations utilizing imaging genetics methodologies. We also highlight the genetic variants supposedly allied with the development of ADHD and how these, in turn, may affect the brain circuit function and related behaviors. In addition to reviewing imaging genetic studies, we also examine the need for complementary approaches at various levels of biological complexity and emphasize the importance of combining and integrating results to explore biological pathways involved in ADHD disorder. These approaches include animal models, computational biology, bioinformatics analyses, and multimodal imaging genetics studies.
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19
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Ma D, Huang R, Guo K, Zhao Z, Wei W, Gu L, Li L, Zhang L. Cornel Iridoid Glycoside Protects Against STAT1-Dependent Synapse and Memory Deficits by Increasing N-Methyl-D-aspartate Receptor Expression in a Tau Transgenic Mice. Front Aging Neurosci 2021; 13:671206. [PMID: 34113246 PMCID: PMC8185567 DOI: 10.3389/fnagi.2021.671206] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 04/13/2021] [Indexed: 12/14/2022] Open
Abstract
P301S transgenic mice are an animal model of tauopathy and Alzheimer’s disease (AD), exhibiting tau pathology and synaptic dysfunction. Cornel iridoid glycoside (CIG) is an active ingredient extracted from Cornus officinalis, a traditional Chinese herb. In the present study, the purpose was to investigate the effects and mechanisms of CIG on tau pathology and synaptic dysfunction using P301S transgenic mice. The results showed that intragastric administration of CIG for 3.5 months improved cognitive impairments and the survival rate of P301S mice. Electrophysiological recordings and transmission electron microscopy study showed that CIG improved synaptic plasticity and increased the ultrastructure and number of synapse. Moreover, CIG increased the expression levels of N-methyl-D-aspartate receptors (NMDAR) subunits GluN1, GluN2A, and GluN2B, and α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor (AMPAR) subunit GluA1. We inferred that the major mechanism of CIG involving in the regulation of synaptic dysfunctions was inhibiting the activation of Janus kinase-2 (JAK2)/signal transducer and activator of transcription 1 (STAT1) signaling pathway and alleviating STAT1-induced suppression of NMDAR expressions. Based on our findings, we thought CIG might be a promising candidate for the therapy of tauopathy such as AD.
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Affiliation(s)
- Denglei Ma
- Key Laboratory for Neurodegenerative Diseases of Ministry of Education, Department of Pharmacy, Beijing Institute for Brain Disorders, Beijing Engineering Research Center for Nerve System Drugs, National Clinical Research Center for Geriatric Diseases, Xuanwu Hospital of Capital Medical University, Beijing, China
| | - Rui Huang
- Key Laboratory for Neurodegenerative Diseases of Ministry of Education, Department of Pharmacy, Beijing Institute for Brain Disorders, Beijing Engineering Research Center for Nerve System Drugs, National Clinical Research Center for Geriatric Diseases, Xuanwu Hospital of Capital Medical University, Beijing, China
| | - Kaiwen Guo
- Key Laboratory for Neurodegenerative Diseases of Ministry of Education, Department of Pharmacy, Beijing Institute for Brain Disorders, Beijing Engineering Research Center for Nerve System Drugs, National Clinical Research Center for Geriatric Diseases, Xuanwu Hospital of Capital Medical University, Beijing, China
| | - Zirun Zhao
- Renaissance School of Medicine at Stony Brook University, Stony Brook, NY, United States
| | - Weipeng Wei
- Key Laboratory for Neurodegenerative Diseases of Ministry of Education, Department of Pharmacy, Beijing Institute for Brain Disorders, Beijing Engineering Research Center for Nerve System Drugs, National Clinical Research Center for Geriatric Diseases, Xuanwu Hospital of Capital Medical University, Beijing, China
| | - Lihong Gu
- Key Laboratory for Neurodegenerative Diseases of Ministry of Education, Department of Pharmacy, Beijing Institute for Brain Disorders, Beijing Engineering Research Center for Nerve System Drugs, National Clinical Research Center for Geriatric Diseases, Xuanwu Hospital of Capital Medical University, Beijing, China
| | - Lin Li
- Key Laboratory for Neurodegenerative Diseases of Ministry of Education, Department of Pharmacy, Beijing Institute for Brain Disorders, Beijing Engineering Research Center for Nerve System Drugs, National Clinical Research Center for Geriatric Diseases, Xuanwu Hospital of Capital Medical University, Beijing, China
| | - Lan Zhang
- Key Laboratory for Neurodegenerative Diseases of Ministry of Education, Department of Pharmacy, Beijing Institute for Brain Disorders, Beijing Engineering Research Center for Nerve System Drugs, National Clinical Research Center for Geriatric Diseases, Xuanwu Hospital of Capital Medical University, Beijing, China
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20
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Mamoune KE, Barantin L, Adriaensen H, Tillet Y. Application of Chemical Exchange Saturation Transfer (CEST) in neuroimaging. J Chem Neuroanat 2021; 114:101944. [PMID: 33716103 DOI: 10.1016/j.jchemneu.2021.101944] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 03/02/2021] [Accepted: 03/04/2021] [Indexed: 12/14/2022]
Abstract
Since the early eighties MRI has become the most powerful technic for in-vivo imaging particularly in the field of brain research. This non-invasive method allows acute anatomical observations of the living brain similar to post-mortem dissected tissues. However, one of the main limitation of MRI is that it does not make possible the neurochemical identification of the tissues conversely to positron emission tomography scanner which can provide a specific molecular characterization of tissue, in spite of poor anatomical definition. To gain neurochemical information using MRI, new categories of contrast agents were developed from the beginning of the 2000's, particularly using the chemical-exchange saturation transfer (CEST) method. This method induces a significant change in the magnitude of the water proton signal and allows the detection of specific molecules within the tissues like sugars, amino acids, transmitters, and nucleosides. This short review presents several CEST contrast agents and their recent developments for in vivo detection of metabolites and neurotransmitters in the brain for research and clinical purposes.
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Affiliation(s)
- Kahina El Mamoune
- Physiologie de la Reproduction et des Comportements, UMR 085 INRAE, CNRS 7247, Université de Tours, IFCE, Centre INRAE Val de Loire, 37380 Nouzilly, France; Siemens Healthcare SAS, Saint Denis, France; SFR FED 4226, Université de Tours, 2 Bd Tonnellé, 37032 Tours, France
| | - Laurent Barantin
- iBrain, UMR 1253 INSERM, Université de Tours, 10 Bd Tonnellé, 37032 Tours, France; SFR FED 4226, Université de Tours, 2 Bd Tonnellé, 37032 Tours, France
| | - Hans Adriaensen
- Physiologie de la Reproduction et des Comportements, UMR 085 INRAE, CNRS 7247, Université de Tours, IFCE, Centre INRAE Val de Loire, 37380 Nouzilly, France; CIRE UMR 085 INRAE, CNRS 7247, Université de Tours, IFCE, Centre INRAE Val de Loire, 37380 Nouzilly, France; SFR FED 4226, Université de Tours, 2 Bd Tonnellé, 37032 Tours, France
| | - Yves Tillet
- Physiologie de la Reproduction et des Comportements, UMR 085 INRAE, CNRS 7247, Université de Tours, IFCE, Centre INRAE Val de Loire, 37380 Nouzilly, France; SFR FED 4226, Université de Tours, 2 Bd Tonnellé, 37032 Tours, France.
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21
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Walker CK, Greathouse KM, Boros BD, Poovey EH, Clearman KR, Ramdas R, Muhammad HM, Herskowitz JH. Dendritic Spine Remodeling and Synaptic Tau Levels in PS19 Tauopathy Mice. Neuroscience 2021; 455:195-211. [PMID: 33346120 PMCID: PMC8142378 DOI: 10.1016/j.neuroscience.2020.12.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 11/20/2020] [Accepted: 12/07/2020] [Indexed: 01/13/2023]
Abstract
Synapse or dendritic spine loss is the strongest correlate of cognitive decline in Alzheimer's disease (AD), and neurofibrillary tangles (NFTs), but not amyloid-β plaques, associate more closely with transition to mild cognitive impairment. Yet, how dendritic spine architecture is affected by hyperphosphorylated tau is still an ongoing question. To address this, we combined cell and biochemical analyses of the Tau P301S mouse line (PS19). Individual pyramidal neurons in the hippocampus and medial prefrontal cortex (mPFC) were targeted for iontophoretic microinjection of fluorescent dye, followed by high-resolution confocal microscopy and 3D morphometry analysis. In the hippocampus, PS19 mice and non-transgenic (NTG) littermates displayed equivalent spine density at 6 and 9 months, but both genotypes exhibited age-related thin spine loss. PS19 mice exhibited significant increases in synaptic tau protein levels and mean dendritic spine head diameter with age. This suggests that CA1 pyramidal neurons in PS19 mice may undergo spine remodeling in response to tau accumulation and age. In the mPFC, spine density was similar among PS19 mice and NTG littermates at 6 and 9 months, but age-related reductions in synaptic tau levels were observed among PS19 mice. Collectively, these studies reveal brain region-specific changes in dendritic spine density and morphology in response to age and the presence of hyperphosphorylated tau in the PS19 mouse line.
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Affiliation(s)
- Courtney K Walker
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, University of Alabama at Birmingham, 1825 University Blvd, Birmingham, AL 35294, United States
| | - Kelsey M Greathouse
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, University of Alabama at Birmingham, 1825 University Blvd, Birmingham, AL 35294, United States
| | - Benjamin D Boros
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, University of Alabama at Birmingham, 1825 University Blvd, Birmingham, AL 35294, United States
| | - Emily H Poovey
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, University of Alabama at Birmingham, 1825 University Blvd, Birmingham, AL 35294, United States
| | - Kelsey R Clearman
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, University of Alabama at Birmingham, 1825 University Blvd, Birmingham, AL 35294, United States
| | - Raksha Ramdas
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, University of Alabama at Birmingham, 1825 University Blvd, Birmingham, AL 35294, United States
| | - Hamad M Muhammad
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, University of Alabama at Birmingham, 1825 University Blvd, Birmingham, AL 35294, United States
| | - Jeremy H Herskowitz
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, University of Alabama at Birmingham, 1825 University Blvd, Birmingham, AL 35294, United States.
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22
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Longitudinal GluCEST MRI Changes and Cerebral Blood Flow in 5xFAD Mice. CONTRAST MEDIA & MOLECULAR IMAGING 2020; 2020:8831936. [PMID: 33304204 PMCID: PMC7714610 DOI: 10.1155/2020/8831936] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 11/05/2020] [Accepted: 11/11/2020] [Indexed: 11/17/2022]
Abstract
Many of the focal neurological symptoms associated with Alzheimer's disease (AD) are due to synaptic loss. Glutamate chemical exchange saturation transfer (GluCEST) magnetic resonance imaging (MRI) is a candidate method to assess synaptic dysfunction. We assessed chronological changes in GluCEST in a 5xFAD mouse model of AD, comparing Glucest effects and regional cerebral blood flow (CBF). GluCEST effects and CBF in 5xFAD mice aged 1–15 months and their littermates (WT) were measured. Neurite orientation dispersion and density imaging (NODDI) MRI reflecting dendritic/axonal density was also measured and compared with GluCEST in 7-month-old mice. While regional CBF's decrease began at 7 months, GluCEST-reduction effects preceded hypoperfusion of the temporal cortex and hippocampus. While longitudinal 5xFAD mouse measurements revealed a correlation between the regional GluCEST effects and CBF, a generalized linear mixed model revealed statistically different correlations in cortical and basal brain regions. Further, NODDI-derived neurite density correlated with GluCEST effects in the parietal cortex, but not in the hippocampus, thereby revealing regional differences in pathophysiological mechanisms. Finally, GluCEST's effects correlated with regional synaptophysin. These results demonstrate that GluCEST can reflect subtle synaptic changes and may be a potential imaging method for AD diagnosis as well as serve as a biomarker of AD progression.
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23
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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.
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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.
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24
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L-3-n-Butylphthalide improves synaptic and dendritic spine plasticity and ameliorates neurite pathology in Alzheimer's disease mouse model and cultured hippocampal neurons. Mol Neurobiol 2020; 58:1260-1274. [PMID: 33146400 DOI: 10.1007/s12035-020-02183-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 10/20/2020] [Indexed: 01/23/2023]
Abstract
Alzheimer's disease (AD) is the most common cause of dementia among elderly people. Despite enormous efforts, the pathogenesis of AD still remains unclear and no drug has yet been proved to be disease-modifying. As the basis of learning and memory, the plasticity of synapse and dendritic spine has been impaired during AD progression. Previous studies have showed a protective effect of L-3-n-butylphthalide (L-NBP) on cognitive deficits in AD, we wonder whether this protective effect is associated with positive alterations on synapse and dendritic spines. In this study, we first of all confirmed the anti-dementia effect of L-NBP in 13-month-old APP/PS1 mice, and then investigated the alterations in synaptic and dendritic spine plasticity due to L-NBP treatment both in vivo and in vitro. We also conducted preliminary studies and found the possible mechanisms related to the inhibition of over-activated complement cascade and the remodeling of actin cytoskeleton. Besides, we also found extra benefits of L-NBP on presynaptic dystrophic neurites and attempted to give explanations from the view of autophagy regulation. Taken together, our study added some new evidence to the application of L-NBP in AD treatment and provided deeper insight into the relevant mechanisms for future study.
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25
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Hascup KN, Findley CA, Sime LN, Hascup ER. Hippocampal alterations in glutamatergic signaling during amyloid progression in AβPP/PS1 mice. Sci Rep 2020; 10:14503. [PMID: 32879385 PMCID: PMC7467928 DOI: 10.1038/s41598-020-71587-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 08/18/2020] [Indexed: 11/17/2022] Open
Abstract
Our previous research demonstrated that soluble amyloid-β (Aβ)42, elicits presynaptic glutamate release. We hypothesized that accumulation and deposition of Aβ altered glutamatergic neurotransmission in a temporally and spatially dependent manner. To test this hypothesis, a glutamate selective microelectrode array (MEA) was used to monitor dentate (DG), CA3, and CA1 hippocampal extracellular glutamate levels in 2–4, 6–8, and 18–20 month-old male AβPP/PS1 and age-matched C57BL/6J control mice. Starting at 6 months of age, AβPP/PS1 basal glutamate levels are elevated in all three hippocampal subregions that becomes more pronounced at the oldest age group. Evoked glutamate release was elevated in all three age groups in the DG, but temporally delayed to 18–20 months in the CA3 of AβPP/PS1 mice. However, CA1 evoked glutamate release in AβPP/PS1 mice was elevated at 2–4 months of age and declined with age. Plaque deposition was anatomically aligned (but temporally delayed) with elevated glutamate levels; whereby accumulation was first observed in the CA1 and DG starting at 6–8 months that progressed throughout all hippocampal subregions by 18–20 months of age. The temporal hippocampal glutamate changes observed in this study may serve as a biomarker allowing for time point specific therapeutic interventions in Alzheimer’s disease patients.
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Affiliation(s)
- Kevin N Hascup
- Department of Neurology, Center for Alzheimer's Disease and Related Disorders, Neurosciences Institute, Southern Illinois University School of Medicine, P.O. Box 19628, Springfield, IL, 62794-9628, USA.,Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL, USA.,Department of Medical Microbiology, Immunology, and Cell Biology, Southern Illinois University School of Medicine, Springfield, IL, USA
| | - Caleigh A Findley
- Department of Neurology, Center for Alzheimer's Disease and Related Disorders, Neurosciences Institute, Southern Illinois University School of Medicine, P.O. Box 19628, Springfield, IL, 62794-9628, USA.,Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL, USA
| | - Lindsey N Sime
- Department of Neurology, Center for Alzheimer's Disease and Related Disorders, Neurosciences Institute, Southern Illinois University School of Medicine, P.O. Box 19628, Springfield, IL, 62794-9628, USA
| | - Erin R Hascup
- Department of Neurology, Center for Alzheimer's Disease and Related Disorders, Neurosciences Institute, Southern Illinois University School of Medicine, P.O. Box 19628, Springfield, IL, 62794-9628, USA. .,Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL, USA.
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26
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Li Y, Xie D, Cember A, Nanga RPR, Yang H, Kumar D, Hariharan H, Bai L, Detre JA, Reddy R, Wang Z. Accelerating GluCEST imaging using deep learning for B 0 correction. Magn Reson Med 2020; 84:1724-1733. [PMID: 32301185 DOI: 10.1002/mrm.28289] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 03/27/2020] [Accepted: 03/27/2020] [Indexed: 02/06/2023]
Abstract
PURPOSE Glutamate weighted Chemical Exchange Saturation Transfer (GluCEST) MRI is a noninvasive technique for mapping parenchymal glutamate in the brain. Because of the sensitivity to field (B0 ) inhomogeneity, the total acquisition time is prolonged due to the repeated image acquisitions at several saturation offset frequencies, which can cause practical issues such as increased sensitivity to patient motions. Because GluCEST signal is derived from the small z-spectrum difference, it often has a low signal-to-noise-ratio (SNR). We proposed a novel deep learning (DL)-based algorithm armed with wide activation neural network blocks to address both issues. METHODS B0 correction based on reduced saturation offset acquisitions was performed for the positive and negative sides of the z-spectrum separately. For each side, a separate deep residual network was trained to learn the nonlinear mapping from few CEST-weighted images acquired at different ppm values to the one at 3 ppm (where GluCEST peaks) in the same side of the z-spectrum. RESULTS All DL-based methods outperformed the "traditional" method visually and quantitatively. The wide activation blocks-based method showed the highest performance in terms of Structural Similarity Index (SSIM) and peak signal-to-noise ratio (PSNR), which were 0.84 and 25dB respectively. SNR increases in regions of interest were over 8dB. CONCLUSION We demonstrated that the new DL-based method can reduce the entire GluCEST imaging time by ˜50% and yield higher SNR than current state-of-the-art.
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Affiliation(s)
- Yiran Li
- Department of Electrical and Computer Engineering, Temple University, Philadelphia, Pennsylvania, USA
| | - Danfeng Xie
- Department of Electrical and Computer Engineering, Temple University, Philadelphia, Pennsylvania, USA
| | - Abigail Cember
- Department of Radiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Ravi Prakash Reddy Nanga
- Department of Radiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Hanlu Yang
- Department of Electrical and Computer Engineering, Temple University, Philadelphia, Pennsylvania, USA
| | - Dushyant Kumar
- Department of Radiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Hari Hariharan
- Department of Radiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Li Bai
- Department of Electrical and Computer Engineering, Temple University, Philadelphia, Pennsylvania, USA
| | - John A Detre
- Department of Neurology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Ravinder Reddy
- Department of Radiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Ze Wang
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA
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27
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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.
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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,
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28
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Van Erum J, Valkenburg F, Van Dam D, De Deyn PP. Pentylenetetrazole-induced Seizure Susceptibility in the Tau58/4 Transgenic Mouse Model of Tauopathy. Neuroscience 2019; 425:112-122. [PMID: 31785360 DOI: 10.1016/j.neuroscience.2019.11.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 11/04/2019] [Accepted: 11/05/2019] [Indexed: 11/19/2022]
Abstract
In several tauopathies such as Alzheimer's disease (AD), an increased incidence of seizures is observed. Tau, one of the major proteins implicated in AD pathology, is an important regulator of neural network excitability and might participate in the underlying epileptic cascade. However, the mechanisms underlying this relationship are not fully elucidated. We aim to investigate this mechanism by analyzing seizure susceptibility to the convulsant pentylenetetrazole (PTZ) in a novel rodent tauopathy model. A single dose of PTZ was systemically injected in Tau58/4 transgenic mice. To investigate whether young and aged heterozygous (HET) mice exhibit a higher susceptibility to seizures in comparison with wild-type (WT) littermates, video electroencephalography (EEG) in combination with behavioral scoring according to a modified Racine scale was used. The employment of different dosage groups enabled us to characterize the dose range reliably inducing seizures. Here, we report an increased seizure susceptibility in young but not in old HET Tau58/4 mice. Young HET animals displayed more severe seizures and had a reduced latency to the first seizure compared to WTs. Also, age-related differences in susceptibility could be demonstrated for both genotypes. Identification and targeting of secondary diseases such as epilepsy, which aggravate dementia and lead to earlier institutionalization, is key. This study finds that tau pathology itself is sufficient to alter seizure susceptibility in a rodent model, indicating that the disease process is crucial in the emergence of epilepsy in patients with tauopathy.
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Affiliation(s)
- Jan Van Erum
- Laboratory of Neurochemistry and Behavior, Institute Born-Bunge, Department of Biomedical Sciences, University of Antwerp, Wilrijk (Antwerp), Belgium
| | - Femke Valkenburg
- Laboratory of Neurochemistry and Behavior, Institute Born-Bunge, Department of Biomedical Sciences, University of Antwerp, Wilrijk (Antwerp), Belgium
| | - Debby Van Dam
- Laboratory of Neurochemistry and Behavior, Institute Born-Bunge, Department of Biomedical Sciences, University of Antwerp, Wilrijk (Antwerp), Belgium; Department of Neurology and Alzheimer Center, University of Groningen and University Medical Center Groningen (UMCG), Groningen, The Netherlands
| | - Peter Paul De Deyn
- Laboratory of Neurochemistry and Behavior, Institute Born-Bunge, Department of Biomedical Sciences, University of Antwerp, Wilrijk (Antwerp), Belgium; Department of Neurology and Alzheimer Center, University of Groningen and University Medical Center Groningen (UMCG), Groningen, The Netherlands; Department of Neurology, Memory Clinic of Hospital Network Antwerp (ZNA) Middelheim and Hoge Beuken, Antwerp, Belgium.
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29
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Cui J, Zu Z. Towards the molecular origin of glutamate CEST (GluCEST) imaging in rat brain. Magn Reson Med 2019; 83:1405-1417. [DOI: 10.1002/mrm.28021] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 09/04/2019] [Accepted: 09/05/2019] [Indexed: 12/24/2022]
Affiliation(s)
- Jing Cui
- Vanderbilt University Institute of Imaging Science Nashville Tennessee
- Department of Radiology and Radiological Sciences Vanderbilt University Nashville Tennessee
| | - Zhongliang Zu
- Vanderbilt University Institute of Imaging Science Nashville Tennessee
- Department of Radiology and Radiological Sciences Vanderbilt University Nashville Tennessee
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30
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Perlman O, Herz K, Zaiss M, Cohen O, Rosen MS, Farrar CT. CEST MR-Fingerprinting: Practical considerations and insights for acquisition schedule design and improved reconstruction. Magn Reson Med 2019; 83:462-478. [PMID: 31400034 DOI: 10.1002/mrm.27937] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 06/19/2019] [Accepted: 07/17/2019] [Indexed: 01/13/2023]
Abstract
PURPOSE To understand the influence of various acquisition parameters on the ability of CEST MR-Fingerprinting (MRF) to discriminate different chemical exchange parameters and to provide tools for optimal acquisition schedule design and parameter map reconstruction. METHODS Numerical simulations were conducted using a parallel computing implementation of the Bloch-McConnell equations, examining the effect of TR, TE, flip-angle, water T 1 and T 2 , saturation-pulse duration, power, and frequency on the discrimination ability of CEST-MRF. A modified Euclidean distance matching metric was evaluated and compared to traditional dot product matching. L-Arginine phantoms of various concentrations and pH were scanned at 4.7T and the results compared to numerical findings. RESULTS Simulations for dot product matching demonstrated that the optimal flip-angle and saturation times are 30 ∘ and 1100 ms, respectively. The optimal maximal saturation power was 3.4 μT for concentrated solutes with a slow exchange rate, and 5.2 μT for dilute solutes with medium-to-fast exchange rates. Using the Euclidean distance matching metric, much lower maximum saturation powers were required (1.6 and 2.4 μT, respectively), with a slightly longer saturation time (1500 ms) and 90 ∘ flip-angle. For both matching metrics, the discrimination ability increased with the repetition time. The experimental results were in agreement with simulations, demonstrating that more than a 50% reduction in scan-time can be achieved by Euclidean distance-based matching. CONCLUSIONS Optimization of the CEST-MRF acquisition schedule is critical for obtaining the best exchange parameter accuracy. The use of Euclidean distance-based matching of signal trajectories simultaneously improved the discrimination ability and reduced the scan time and maximal saturation power required.
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Affiliation(s)
- Or Perlman
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts
| | - Kai Herz
- Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, Tübingen, Germany.,IMPRS for Cognitive and Systems Neuroscience, University of Tübingen, Tübingen, Germany
| | - Moritz Zaiss
- Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
| | - Ouri Cohen
- Memorial Sloan Kettering Cancer Center, New York, New York
| | - Matthew S Rosen
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts.,Department of Physics, Harvard University, Cambridge, Massachusetts
| | - Christian T Farrar
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts
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31
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Sugar alcohol provides imaging contrast in cancer detection. Sci Rep 2019; 9:11092. [PMID: 31366892 PMCID: PMC6668433 DOI: 10.1038/s41598-019-47275-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 07/09/2019] [Indexed: 01/30/2023] Open
Abstract
Clinical imaging is widely used to detect, characterize and stage cancers in addition to monitoring the therapeutic progress. Magnetic resonance imaging (MRI) aided by contrast agents utilizes the differential relaxivity property of water to distinguish between tumorous and normal tissue. Here, we describe an MRI contrast method for the detection of cancer using a sugar alcohol, maltitol, a common low caloric sugar substitute that exploits the chemical exchange saturation transfer (CEST) property of the labile hydroxyl group protons on maltitol (malCEST). In vitro studies pointed toward concentration and pH-dependent CEST effect peaking at 1 ppm downfield to the water resonance. Studies with control rats showed that intravenously injected maltitol does not cross the intact blood-brain barrier (BBB). In glioma carrying rats, administration of maltitol resulted in the elevation of CEST contrast in the tumor region only owing to permeable BBB. These preliminary results show that this method may lead to the development of maltitol and other sugar alcohol derivatives as MRI contrast agents for a variety of preclinical imaging applications.
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32
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Vemula P, Jing Y, Zhang H, Hunt JB, Sandusky‑Beltran LA, Lee DC, Liu P. Altered brain arginine metabolism in a mouse model of tauopathy. Amino Acids 2019; 51:513-528. [PMID: 30604097 PMCID: PMC6431576 DOI: 10.1007/s00726-018-02687-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 12/12/2018] [Indexed: 12/26/2022]
Abstract
Tauopathies consist of intracellular accumulation of hyperphosphorylated and aggregated microtubule protein tau, which remains a histopathological feature of Alzheimer's disease (AD) and frontotemporal dementia. L-Arginine is a semi-essential amino acid with a number of bioactive molecules. Its downstream metabolites putrescine, spermidine, and spermine (polyamines) are critically involved in microtubule assembly and stabilization. Recent evidence implicates altered arginine metabolism in the pathogenesis of AD. Using high-performance liquid chromatographic and mass spectrometric assays, the present study systematically determined the tissue concentrations of L-arginine and its nine downstream metabolites in the frontal cortex, hippocampus, parahippocampal region, striatum, thalamus, and cerebellum in male PS19 mice-bearing human tau P301S mutation at 4, 8, and 12-14 months of age. As compared to their wild-type littermates, PS19 mice displayed early and/or prolonged increases in L-ornithine and altered polyamine levels with age. There were also genotype- and age-related changes in L-arginine, L-citrulline, glutamine, glutamate, and γ-aminobutyric acid in a region- and/or chemical-specific manner. The results demonstrate altered brain arginine metabolism in PS19 mice with the most striking changes in L-ornithine, polyamines, and glutamate, indicating a shift of L-arginine metabolism to favor the arginase-polyamine pathway. Given the role of polyamines in maintaining microtubule stability, the functional significance of these changes remains to be explored in future research.
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Affiliation(s)
- Pranav Vemula
- Department of Anatomy, School of Biomedical Sciences, Brain Health Research Centre, University of Otago, Dunedin, New Zealand
- Brain Research New Zealand, Dunedin, New Zealand
| | - Yu Jing
- Department of Anatomy, School of Biomedical Sciences, Brain Health Research Centre, University of Otago, Dunedin, New Zealand
- Brain Research New Zealand, Dunedin, New Zealand
| | - Hu Zhang
- School of Pharmacy, Brain Health Research Centre, University of Otago, Dunedin, New Zealand
- Brain Research New Zealand, Dunedin, New Zealand
| | - Jerry B. Hunt
- Byrd Alzheimer’s Institute, College of Pharmacy and Pharmaceutical Sciences, University of South Florida, Florida, USA
| | - Leslie A. Sandusky‑Beltran
- Byrd Alzheimer’s Institute, College of Pharmacy and Pharmaceutical Sciences, University of South Florida, Florida, USA
| | - Daniel C. Lee
- Byrd Alzheimer’s Institute, College of Pharmacy and Pharmaceutical Sciences, University of South Florida, Florida, USA
| | - Ping Liu
- Department of Anatomy, School of Biomedical Sciences, Brain Health Research Centre, University of Otago, Dunedin, New Zealand
- School of Pharmacy, Brain Health Research Centre, University of Otago, Dunedin, New Zealand
- Brain Research New Zealand, Dunedin, New Zealand
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33
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Zhuang Z, Shen Z, Chen Y, Dai Z, Zhang X, Mao Y, Zhang B, Zeng H, Chen P, Wu R. Mapping the Changes of Glutamate Using Glutamate Chemical Exchange Saturation Transfer (GluCEST) Technique in a Traumatic Brain Injury Model: A Longitudinal Pilot Study. ACS Chem Neurosci 2019; 10:649-657. [PMID: 30346712 DOI: 10.1021/acschemneuro.8b00482] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Glutamate excitoxicity plays a crucial role in the pathophysiology of traumatic brain injury (TBI) through the initiation of secondary injuries. Glutamate chemical exchange saturation transfer (GluCEST) MRI is a newly developed technique to noninvasively image glutamate in vivo with high sensitivity and spatial resolution. The aim of the present study was to use a rat model of TBI to map changes in brain glutamate distribution and explore the capability of GluCEST imaging for detecting secondary injuries. Sequential GluCEST imaging scans were performed in adult male Sprague-Dawley rats before TBI and at 1, 3, 7, and 14 days after TBI. GluCEST% increased and peaked on day 1 after TBI in the core lesion of injured cortex and peaked on day 3 in the ipsilateral hippocampus, as compared to baseline and controls. GluCEST% gradually declined to baseline by day 14 after TBI. A negative correlation between the GluCEST% of the ipsilateral hippocampus on day 3 and the time in the correct quadrant was observed in injured rats. Immunolabeling for glial fibrillary acidic protein showed significant astrocyte activation in the ipsilateral hippocampus of TBI rats. IL-6 and TNF-α in the core lesion peaked on day 1 postinjury, while those in the ipsilateral hippocampus peaked on day 3. These subsequently gradually declined to sham levels by day 14. It was concluded that GluCEST imaging has potential to be a novel neuroimaging approach for predicting cognitive outcome and to better understand neuroinflammation following TBI.
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Affiliation(s)
- Zerui Zhuang
- Department of Neurosurgery, The Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, China
| | - Zhiwei Shen
- Department of Radiology, The Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, China
| | - Yanzi Chen
- Department of Radiology, The Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, China
| | - Zhuozhi Dai
- Department of Radiology, The Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, China
| | - Xiaolei Zhang
- Department of Radiology, The Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, China
| | - Yifei Mao
- Department of Radiology, The Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, China
| | - Bingna Zhang
- Translational Medicine, The Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, China
| | - Haiyan Zeng
- Medical College of Shantou University, Shantou 515041, China
| | - Peidong Chen
- Department of Radiology, The Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, China
| | - Renhua Wu
- Department of Radiology, The Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, China
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34
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Nanga RPR, DeBrosse C, Kumar D, Roalf D, McGeehan B, D'Aquilla K, Borthakur A, Hariharan H, Reddy D, Elliott M, Detre JA, Epperson CN, Reddy R. Reproducibility of 2D GluCEST in healthy human volunteers at 7 T. Magn Reson Med 2018; 80:2033-2039. [PMID: 29802635 PMCID: PMC6107408 DOI: 10.1002/mrm.27362] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 04/11/2018] [Accepted: 04/24/2018] [Indexed: 01/06/2023]
Abstract
PURPOSE To investigate the reproducibility of gray and white matter glutamate contrast of a brain slice among a small group of healthy volunteers by using the 2D single-slice glutamate CEST (GluCEST) imaging technique. METHODS Six healthy volunteers were scanned multiple times for within-day and between-day reproducibility. One more volunteer was scanned for within-day reproducibility at 7T MRI. Glutamate CEST contrast measurements were calculated for within subjects and among the subjects and the coefficient of variations are reported. RESULTS The GluCEST measurements were highly reproducible in the gray and white matter area of the brain slice, whether it was within-day or between-day with a coefficient of variation of less than 5%. CONCLUSION This preliminary study in a small group of healthy volunteers shows a high degree of reproducibility of GluCEST MRI in brain and holds promise for implementation in studying age-dependent changes in the brain.
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Affiliation(s)
- Ravi Prakash Reddy Nanga
- Department of RadiologyUniversity of Pennsylvania Perelman School of MedicinePhiladelphiaPennsylvania
| | - Catherine DeBrosse
- Department of RadiologyUniversity of Pennsylvania Perelman School of MedicinePhiladelphiaPennsylvania
| | - Dushyant Kumar
- Department of RadiologyUniversity of Pennsylvania Perelman School of MedicinePhiladelphiaPennsylvania
| | - David Roalf
- Department of PsychiatryUniversity of Pennsylvania Perelman School of MedicinePhiladelphiaPennsylvania
| | - Brendan McGeehan
- Department of PsychiatryUniversity of Pennsylvania Perelman School of MedicinePhiladelphiaPennsylvania
| | - Kevin D'Aquilla
- Department of RadiologyUniversity of Pennsylvania Perelman School of MedicinePhiladelphiaPennsylvania
| | - Arijitt Borthakur
- Department of RadiologyUniversity of Pennsylvania Perelman School of MedicinePhiladelphiaPennsylvania
| | - Hari Hariharan
- Department of RadiologyUniversity of Pennsylvania Perelman School of MedicinePhiladelphiaPennsylvania
| | - Damodara Reddy
- Department of RadiologyUniversity of Pennsylvania Perelman School of MedicinePhiladelphiaPennsylvania
| | - Mark Elliott
- Department of RadiologyUniversity of Pennsylvania Perelman School of MedicinePhiladelphiaPennsylvania
| | - John A. Detre
- Department of NeurologyUniversity of Pennsylvania Perelman School of MedicinePhiladelphiaPennsylvania
| | - Cynthia Neill Epperson
- Department of PsychiatryUniversity of Pennsylvania Perelman School of MedicinePhiladelphiaPennsylvania
| | - Ravinder Reddy
- Department of RadiologyUniversity of Pennsylvania Perelman School of MedicinePhiladelphiaPennsylvania
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35
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Edison P, Donat CK, Sastre M. In vivo Imaging of Glial Activation in Alzheimer's Disease. Front Neurol 2018; 9:625. [PMID: 30131755 PMCID: PMC6090997 DOI: 10.3389/fneur.2018.00625] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 07/10/2018] [Indexed: 12/12/2022] Open
Abstract
Alzheimer's disease (AD) is characterized by memory loss and decline of cognitive function, associated with progressive neurodegeneration. While neuropathological processes like amyloid plaques and tau neurofibrillary tangles have been linked to neuronal death in AD, the precise role of glial activation on disease progression is still debated. It was suggested that neuroinflammation could occur well ahead of amyloid deposition and may be responsible for clearing amyloid, having a neuroprotective effect; however, later in the disease, glial activation could become deleterious, contributing to neuronal toxicity. Recent genetic and preclinical studies suggest that the different activation states of microglia and astrocytes are complex, not as polarized as previously thought, and that the heterogeneity in their phenotype can switch during disease progression. In the last few years, novel imaging techniques e.g., new radiotracers for assessing glia activation using positron emission tomography and advanced magnetic resonance imaging technologies have emerged, allowing the correlation of neuro-inflammatory markers with cognitive decline, brain function and brain pathology in vivo. Here we review all new imaging technology in AD patients and animal models that has the potential to serve for early diagnosis of the disease, to monitor disease progression and to test the efficacy and the most effective time window for potential anti-inflammatory treatments.
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Affiliation(s)
- Paul Edison
- Division of Brain Sciences, Department of Medicine, Imperial College London, London, United Kingdom
| | - Cornelius K Donat
- Division of Brain Sciences, Department of Medicine, Imperial College London, London, United Kingdom
| | - Magdalena Sastre
- Division of Brain Sciences, Department of Medicine, Imperial College London, London, United Kingdom
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36
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Zhou R, Bagga P, Nath K, Hariharan H, Mankoff DA, Reddy R. Glutamate-Weighted Chemical Exchange Saturation Transfer Magnetic Resonance Imaging Detects Glutaminase Inhibition in a Mouse Model of Triple-Negative Breast Cancer. Cancer Res 2018; 78:5521-5526. [PMID: 30072394 DOI: 10.1158/0008-5472.can-17-3988] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 05/25/2018] [Accepted: 07/30/2018] [Indexed: 11/16/2022]
Abstract
Glutamate is an important metabolite of glutaminolysis, a metabolic pathway used by many aggressive cancers, including triple-negative breast cancer (TNBC). With the exception of the brain, in vivo detection of glutamate in tissues using 1H magnetic resonance spectroscopy (MRS) is challenging. Compared with MRS, glutamate-weighted chemical exchange saturation transfer MR imaging (GluCEST MRI) offers a more sensitive detection mechanism that is free of glutamine interference. Here, we developed a robust, highly repeatable GluCEST MRI protocol in mice bearing human TNBC xenografts and treated with a potent glutaminase inhibitor, CB-839. In paired studies, treatment with CB-839 for 2 days reduced the GluCEST asymmetry value compared with baseline (P < 0.05, n = 10). The absolute change of the GluCEST asymmetry value was -2.5 percent points after CB-839 treatment versus +0.3 after vehicle (P < 0.01). Correspondingly, treatment with CB-839 reduced tumor glutamate concentrations by 1.5 mmol/L, consistent with prior calibration between changes of the GluCEST value versus tissue glutamate concentration; CB-839, however, did not change tumor intracellular pH. These results demonstrate in a mouse model of breast cancer the utility of GluCEST MRI to detect the early response to glutaminase inhibition.Significance: A sensitive method enables noninvasive detection of tumor response to inhibitors of glutamine metabolism. Cancer Res; 78(19); 5521-6. ©2018 AACR.
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Affiliation(s)
- Rong Zhou
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
| | - Puneet Bagga
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Kavindra Nath
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Hari Hariharan
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - David A Mankoff
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Ravinder Reddy
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
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37
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Tolomeo D, Micotti E, Serra SC, Chappell M, Snellman A, Forloni G. Chemical exchange saturation transfer MRI shows low cerebral 2-deoxy-D-glucose uptake in a model of Alzheimer's Disease. Sci Rep 2018; 8:9576. [PMID: 29934551 PMCID: PMC6015016 DOI: 10.1038/s41598-018-27839-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 06/11/2018] [Indexed: 12/17/2022] Open
Abstract
Glucose is the central nervous system's only energy source. Imaging techniques capable to detect pathological alterations of the brain metabolism are useful in different diagnostic processes. Such techniques are also beneficial for assessing the evaluation efficacy of therapies in pre-clinical and clinical stages of diseases. Chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI) is a possible alternative to positron emission tomography (PET) imaging that has been widely explored in cancer research in humans and animal models. We propose that pathological alterations in brain 2-deoxy-D-glucose (2DG) uptake, typical of neurodegenerative diseases, can be detected with CEST MRI. Transgenic mice overexpressing a mutated form of amyloid precusrsor protein (APP23), a model of Alzheimer's disease, analyzed with CEST MRI showed a clear reduction of 2DG uptake in different brain regions. This was reminiscent of the cerebral condition observed in Alzheimer's patients. The results indicate the feasibility of CEST for analyzing the brain metabolic state, with better image resolution than PET in experimental models.
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Affiliation(s)
- Daniele Tolomeo
- Laboratory of Biology of Neurodegenerative Disorders, Department of Neuroscience, IRCCS, Mario Negri Institute for Pharmacological Research, Milan, (MI), Italy
| | - Edoardo Micotti
- Laboratory of Biology of Neurodegenerative Disorders, Department of Neuroscience, IRCCS, Mario Negri Institute for Pharmacological Research, Milan, (MI), Italy
| | | | - Michael Chappell
- Department of Engineering Science, Institute of Biomedical Engineering, University of Oxford, 6396, Oxford, UK
| | - Anniina Snellman
- Medicity Research Laboratory, University of Turku, (Tykistökatu 6, FI-20510), Turku, Finland.,Turku PET Centre, University of Turku, (Kiinamyllynkatu 4-8, FI-20520,), Turku, Finland
| | - Gianluigi Forloni
- Laboratory of Biology of Neurodegenerative Disorders, Department of Neuroscience, IRCCS, Mario Negri Institute for Pharmacological Research, Milan, (MI), Italy.
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38
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AD-Related N-Terminal Truncated Tau Is Sufficient to Recapitulate In Vivo the Early Perturbations of Human Neuropathology: Implications for Immunotherapy. Mol Neurobiol 2018; 55:8124-8153. [PMID: 29508283 DOI: 10.1007/s12035-018-0974-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 02/19/2018] [Indexed: 01/08/2023]
Abstract
The NH2tau 26-44 aa (i.e., NH2htau) is the minimal biologically active moiety of longer 20-22-kDa NH2-truncated form of human tau-a neurotoxic fragment mapping between 26 and 230 amino acids of full-length protein (htau40)-which is detectable in presynaptic terminals and peripheral CSF from patients suffering from AD and other non-AD neurodegenerative diseases. Nevertheless, whether its exogenous administration in healthy nontransgenic mice is able to elicit a neuropathological phenotype resembling human tauopathies has not been yet investigated. We explored the in vivo effects evoked by subchronic intracerebroventricular (i.c.v.) infusion of NH2htau or its reverse counterpart into two lines of young (2-month-old) wild-type mice (C57BL/6 and B6SJL). Six days after its accumulation into hippocampal parenchyma, significant impairment in memory/learning performance was detected in NH2htau-treated group in association with reduced synaptic connectivity and neuroinflammatory response. Compromised short-term plasticity in paired-pulse facilitation paradigm (PPF) was detected in the CA3/CA1 synapses from NH2htau-impaired animals along with downregulation in calcineurin (CaN)-stimulated pCREB/c-Fos pathway(s). Importantly, these behavioral, synaptotoxic, and neuropathological effects were independent from the genetic background, occurred prior to frank neuronal loss, and were specific because no alterations were detected in the control group infused with its reverse counterpart. Finally, a 2.0-kDa peptide which biochemically and immunologically resembles the injected NH2htau was endogenously detected in vivo, being present in hippocampal synaptosomal preparations from AD subjects. Given that the identification of the neurotoxic tau species is mandatory to develop a more effective tau-based immunological approach, our evidence can have important translational implications for cure of human tauopathies.
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Bagga P, Pickup S, Crescenzi R, Martinez D, Borthakur A, D'Aquilla K, Singh A, Verma G, Detre JA, Greenberg J, Hariharan H, Reddy R. In vivo GluCEST MRI: Reproducibility, background contribution and source of glutamate changes in the MPTP model of Parkinson's disease. Sci Rep 2018; 8:2883. [PMID: 29440753 PMCID: PMC5811435 DOI: 10.1038/s41598-018-21035-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 01/24/2018] [Indexed: 01/01/2023] Open
Abstract
Glutamate Chemical Exchange Saturation Transfer (GluCEST) MRI is a recently developed technique to image glutamate. In the present study, we evaluated the reproducibility and background contamination to the GluCEST and source of the GluCEST changes in a mouse model of Parkinson's disease. Repeated measurements in five mice demonstrated an intra-animal coefficient of variation (CV) of GluCEST signal to be 2.3 ± 1.3% and inter-animal CV of GluCEST to be 3.3 ± 0.3%. Mice were treated with MPTP to create a localized striatal elevation of glutamate. We found an elevation in the GluCEST contrast of the striatum following MPTP treatment (Control: 23.3 ± 0.8%, n = 16; MPTP: 26.2 ± 0.8%, n = 19; p ≤ 0.001). Additionally, the positive association between glutamate concentration measured via 1H MRS and GluCEST signal was used to estimate background contribution to the measured GluCEST. The contribution of signal from non-glutamate sources was found to be ~28% of the total GluCEST. Immunohistochemical analysis of the brain showed co-localization of glutamate with GFAP in the striatum. This suggests that the elevated glutamate present in the striatum in this mouse model reflects astroglial proliferation or reactivity due to the action of MPTP. The potential of GluCEST as a biomarker for imaging inflammation mediated gliosis is discussed.
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Affiliation(s)
- Puneet Bagga
- Center for Magnetic Resonance and Optical Imaging, Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States.
| | - Stephen Pickup
- Center for Magnetic Resonance and Optical Imaging, Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
| | - Rachelle Crescenzi
- Center for Magnetic Resonance and Optical Imaging, Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
| | - Daniel Martinez
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Arijitt Borthakur
- Center for Magnetic Resonance and Optical Imaging, Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
| | - Kevin D'Aquilla
- Center for Magnetic Resonance and Optical Imaging, Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
| | - Anup Singh
- Centre for Biomedical Engineering, Indian institute of Technology, New Delhi, India
| | - Gaurav Verma
- Center for Magnetic Resonance and Optical Imaging, Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
| | - John A Detre
- Center for Magnetic Resonance and Optical Imaging, Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | - Joel Greenberg
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | - Hari Hariharan
- Center for Magnetic Resonance and Optical Imaging, Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
| | - Ravinder Reddy
- Center for Magnetic Resonance and Optical Imaging, Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States.
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40
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Zhang XY, Wang F, Xu J, Gochberg DF, Gore JC, Zu Z. Increased CEST specificity for amide and fast-exchanging amine protons using exchange-dependent relaxation rate. NMR IN BIOMEDICINE 2018; 31:10.1002/nbm.3863. [PMID: 29193448 PMCID: PMC5773365 DOI: 10.1002/nbm.3863] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 10/22/2017] [Accepted: 10/25/2017] [Indexed: 05/10/2023]
Abstract
Chemical exchange saturation transfer (CEST) imaging of amides at 3.5 ppm and fast-exchanging amines at 3 ppm provides a unique means to enhance the sensitivity of detection of, for example, proteins/peptides and neurotransmitters, respectively, and hence can provide important information on molecular composition. However, despite the high sensitivity relative to conventional magnetic resonance spectroscopy (MRS), in practice, CEST often has relatively poor specificity. For example, CEST signals are typically influenced by several confounding effects, including direct water saturation (DS), semi-solid non-specific magnetization transfer (MT), the influence of water relaxation times (T1w ) and nearby overlapping CEST signals. Although several editing techniques have been developed to increase the specificity by removing DS, semi-solid MT and T1w influences, it is still challenging to remove overlapping CEST signals from different exchanging sites. For instance, the amide proton transfer (APT) signal could be contaminated by CEST effects from fast-exchanging amines at 3 ppm and intermediate-exchanging amines at 2 ppm. The current work applies an exchange-dependent relaxation rate (Rex ) to address this problem. Simulations demonstrate that: (1) slowly exchanging amides and fast-exchanging amines have distinct dependences on irradiation powers; and (2) Rex serves as a resonance frequency high-pass filter to selectively reduce CEST signals with resonance frequencies closer to water. These characteristics of Rex provide a means to isolate the APT signal from amines. In addition, previous studies have shown that CEST signals from fast-exchanging amines have no distinct features around their resonance frequencies. However, Rex gives Lorentzian lineshapes centered at their resonance frequencies for fast-exchanging amines and thus can significantly increase the specificity of CEST imaging for amides and fast-exchanging amines.
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Affiliation(s)
- Xiao-Yong Zhang
- Vanderbilt University Institute of Imaging Science
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center
| | - Feng Wang
- Vanderbilt University Institute of Imaging Science
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center
| | - Junzhong Xu
- Vanderbilt University Institute of Imaging Science
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center
- Department of Physics and Astronomy, Vanderbilt University
- Department of Biomedical Engineering, Vanderbilt University
| | - Daniel F. Gochberg
- Vanderbilt University Institute of Imaging Science
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center
- Department of Physics and Astronomy, Vanderbilt University
| | - John C. Gore
- Vanderbilt University Institute of Imaging Science
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center
- Department of Physics and Astronomy, Vanderbilt University
- Department of Biomedical Engineering, Vanderbilt University
- Department of Molecular Physiology and Biophysics
| | - Zhongliang Zu
- Vanderbilt University Institute of Imaging Science
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center
- Correspondence to: Zhongliang Zu, Ph.D., Vanderbilt University Institute of Imaging Science, 1161 21st Ave. S, Medical Center North, AAA-3112, Nashville, TN 37232-2310, , Phone: 615-875-9815, Fax: 615-322-0734
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Flament J, Hantraye P, Valette J. In Vivo Multidimensional Brain Imaging in Huntington's Disease Animal Models. Methods Mol Biol 2018; 1780:285-301. [PMID: 29856025 DOI: 10.1007/978-1-4939-7825-0_15] [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] [Indexed: 06/08/2023]
Abstract
Huntington's disease (HD) is a genetic neurodegenerative disorder caused by an abnormal expansion of a CAG repeat located in the gene encoding for huntingtin protein. This mutation induces the expression of a polyglutamine stretch in the mutated protein resulting in the modification of various biological properties of the wild-type protein and the progressive appearance of motor, cognitive, and psychiatric disorders that are typically associated to this condition. Although the exact neuropathological mechanisms of degeneration are still not fully understood, HD pathology is characterized by severe neuronal losses in various brain regions including the basal ganglia and many cortical areas. Early signs of astrogliosis may precede actual neuronal degeneration. Early metabolic impairment at least in part associated with mitochondrial complex II deficiency may play a key role in huntingtin-induced mechanisms of neurodegeneration. Clinical trials are actively prepared including various gene-silencing approaches aiming at decreasing mutated huntingtin production. However, with the lack of a specific imaging biomarker capable of visualizing mutated huntingtin or huntingtin aggregates, there is a need for surrogate markers of huntingtin neurodegeneration. MRI and caudate nucleus atrophy is one of the most sensitive imaging biomarkers of HD. As such it can be used as a means to study disease progression and potential halting of the neurodegenerative process by therapeutic intervention, but this marker relies on actual neuronal loss which is a somewhat a late event in the pathology. As a means to develop, characterize and evaluate new, potentially earlier biomarkers of HD pathology we have recently embarked on a series of NMR developments looking for brain imaging techniques that allow for noninvasive longitudinal evaluation/characterization of functional alterations in animal models of HD. This chapter describes an assemblage of innovative NMR methods that have proved useful in detecting pathological cell dysfunctions in various preclinical models of HD.
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Affiliation(s)
- Julien Flament
- CEA, DRF, Institut de biologie François Jacob, Molecular Imaging Research Center (MIRCen), Fontenay-aux-Roses, France
- INSERM, US27, Fontenay-aux-Roses, France
| | - Philippe Hantraye
- CEA, DRF, Institut de biologie François Jacob, Molecular Imaging Research Center (MIRCen), Fontenay-aux-Roses, France.
- INSERM, US27, Fontenay-aux-Roses, France.
- CNRS, CEA, Paris-Sud Univ., Univ. Paris-Saclay, Neurodegenerative Diseases Laboratory (UMR9199), Fontenay-aux-Roses, France.
| | - Julien Valette
- CEA, DRF, Institut de biologie François Jacob, Molecular Imaging Research Center (MIRCen), Fontenay-aux-Roses, France
- CNRS, CEA, Paris-Sud Univ., Univ. Paris-Saclay, Neurodegenerative Diseases Laboratory (UMR9199), Fontenay-aux-Roses, France
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Sidoryk-Wegrzynowicz M, Gerber YN, Ries M, Sastre M, Tolkovsky AM, Spillantini MG. Astrocytes in mouse models of tauopathies acquire early deficits and lose neurosupportive functions. Acta Neuropathol Commun 2017; 5:89. [PMID: 29187256 PMCID: PMC6389177 DOI: 10.1186/s40478-017-0478-9] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 10/02/2017] [Indexed: 01/17/2023] Open
Abstract
Microtubule-associated protein tau aggregates constitute the characteristic neuropathological features of several neurodegenerative diseases grouped under the name of tauopathies. It is now clear that the process of tau aggregation is associated with neurodegeneration. Several transgenic tau mouse models have been developed where tau progressively aggregates, causing neuronal death. Previously we have shown that transplantation of astrocytes in P301S tau transgenic mice rescues cortical neuron death, implying that the endogenous astrocytes are deficient in survival support. We now show that the gliosis markers Glial fibrillary acidic protein (GFAP) and S100 calcium-binding protein B (S100β) are elevated in brains from P301S tau mice compared to control C57Bl/6 mice whereas the expression of proteins involved in glutamine/glutamate metabolism are reduced, pointing to a functional deficit. To test whether astrocytes from P301S mice are intrinsically deficient, we co-cultured astrocytes and neurons from control and P301S mice. Significantly more C57-derived and P301S-derived neurons survived when cells were cultured with C57-derived astrocytes or astrocyte conditioned medium (C57ACM) than with P301S-derived astrocytes or astrocyte conditioned medium (P301SACM), or ACM from P301L tau mice, where the transgene is also specifically expressed in neurons. The astrocytic alterations developed in mice during the first postnatal week of life. In addition, P301SACM significantly decreased presynaptic (synaptophysin, SNP) and postsynaptic (postsynaptic density protein 95, PSD95) protein expression in cortical neuron cultures whereas C57ACM enhanced these markers. Since thrombospondin 1 (TSP-1) is a major survival and synaptogenic factor, we examined whether TSP-1 is deficient in P301S mouse brains and ACM. Significantly less TSP-1 was expressed in the brains of P301S tau mice or produced by P301S-derived astrocytes, whereas supplementation of P301SACM with TSP-1 increased its neurosupportive capacity. Our results demonstrate that P301S-derived astrocytes acquire an early functional deficiency that may explain in part the loss of cortical neurons in the P301S tau mice.
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Shimizu M, Suzuki Y, Yamada K, Ueki S, Watanabe M, Igarashi H, Nakada T. Maturational decrease of glutamate in the human cerebral cortex from childhood to young adulthood: a 1H-MR spectroscopy study. Pediatr Res 2017; 82:749-752. [PMID: 28388602 DOI: 10.1038/pr.2017.101] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2016] [Accepted: 04/03/2017] [Indexed: 11/09/2022]
Abstract
BackgroundThe aim of the present study was to investigate maturational changes in glutamate (Glu) in the human cerebral cortex from childhood to young adulthood using 3.0-Tesla proton magnetic resonance spectroscopy (1H-MRS), which is capable of quantifying Glu in vivo.MethodsNormal volunteers comprising 11 children (aged 4-13 years) and 11 young adults (aged 18-33 years) participated in the study. Single-voxel point-resolved spectroscopy (PRESS, repetition time/echo time=2,000/80 ms) was performed on the frontal and occipital cortices, and the Glu-to-creatine ratio (Glu/Cr) and N-acetylaspartate-to-creatine ratio (NAA/Cr) were determined.ResultsIn both the frontal and occipital cortices, Glu/Cr was significantly lower during young adulthood relative to that during childhood. NAA/Cr did not differ significantly between the two age groups.ConclusionThis study has provided objective evidence that cerebral cortical Glu/Cr decreases between childhood and young adulthood. The observed decrease in Glu/Cr may reflect the simultaneous occurrence of maturational changes, such as changes in cortical microstructure and the intercellular compartmentation of Glu metabolism.
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Affiliation(s)
- Mami Shimizu
- Center for Integrated Human Brain Science, Brain Research Institute, University of Niigata, Niigata, Japan
| | - Yuji Suzuki
- Center for Integrated Human Brain Science, Brain Research Institute, University of Niigata, Niigata, Japan
| | - Kenichi Yamada
- Center for Integrated Human Brain Science, Brain Research Institute, University of Niigata, Niigata, Japan
| | - Satoshi Ueki
- Center for Integrated Human Brain Science, Brain Research Institute, University of Niigata, Niigata, Japan
| | - Masaki Watanabe
- Center for Integrated Human Brain Science, Brain Research Institute, University of Niigata, Niigata, Japan
| | - Hironaka Igarashi
- Center for Integrated Human Brain Science, Brain Research Institute, University of Niigata, Niigata, Japan
| | - Tsutomu Nakada
- Center for Integrated Human Brain Science, Brain Research Institute, University of Niigata, Niigata, Japan
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Roalf DR, Nanga RPR, Rupert PE, Hariharan H, Quarmley M, Calkins ME, Dress E, Prabhakaran K, Elliott MA, Moberg PJ, Gur RC, Gur RE, Reddy R, Turetsky BI. Glutamate imaging (GluCEST) reveals lower brain GluCEST contrast in patients on the psychosis spectrum. Mol Psychiatry 2017; 22:1298-1305. [PMID: 28115738 PMCID: PMC5822706 DOI: 10.1038/mp.2016.258] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 10/19/2016] [Accepted: 12/06/2016] [Indexed: 01/05/2023]
Abstract
Psychosis commonly develops in adolescence or early adulthood. Youths at clinical high risk (CHR) for psychosis exhibit similar, subtle symptoms to those with schizophrenia (SZ). Malfunctioning neurotransmitter systems, such as glutamate, are implicated in the disease progression of psychosis. Yet, in vivo imaging techniques for measuring glutamate across the cortex are limited. Here, we use a novel 7 Tesla MRI glutamate imaging technique (GluCEST) to estimate changes in glutamate levels across cortical and subcortical regions in young healthy individuals and ones on the psychosis spectrum. Individuals on the psychosis spectrum (PS; n=19) and healthy young individuals (HC; n=17) underwent MRI imaging at 3 and 7 T. At 7 T, a single slice GluCEST technique was used to estimate in vivo glutamate. GluCEST contrast was compared within and across the subcortex, frontal, parietal and occipital lobes. Subcortical (χ2 (1)=4.65, P=0.031) and lobular (χ2 (1)=5.17, P=0.023) GluCEST contrast levels were lower in PS compared with HC. Abnormal GluCEST contrast levels were evident in both CHR (n=14) and SZ (n=5) subjects, and correlated differentially, across regions, with clinical symptoms. Our findings describe a pattern of abnormal brain neurochemistry early in the course of psychosis. Specifically, CHR and young SZ exhibit diffuse abnormalities in GluCEST contrast attributable to a major contribution from glutamate. We suggest that neurochemical profiles of GluCEST contrast across cortex and subcortex may be considered markers of early psychosis. GluCEST methodology thus shows promise to further elucidate the progression of the psychosis disease state.
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Affiliation(s)
- David R. Roalf
- Neuropsychiatry Section, Department of Psychiatry, University of Pennsylvania, Philadelphia PA 19104, USA
| | - Ravi Prakash Reddy Nanga
- Department of Radiology & Center for Magnetic and Optical Imaging, University of Pennsylvania Perelman School of Medicine, University of Pennsylvania, Philadelphia PA 19104, USA
| | - Petra E. Rupert
- Neuropsychiatry Section, Department of Psychiatry, University of Pennsylvania, Philadelphia PA 19104, USA
| | - Hari Hariharan
- Department of Radiology & Center for Magnetic and Optical Imaging, University of Pennsylvania Perelman School of Medicine, University of Pennsylvania, Philadelphia PA 19104, USA
| | - Megan Quarmley
- Neuropsychiatry Section, Department of Psychiatry, University of Pennsylvania, Philadelphia PA 19104, USA
| | - Monica E. Calkins
- Neuropsychiatry Section, Department of Psychiatry, University of Pennsylvania, Philadelphia PA 19104, USA
| | - Erich Dress
- Neuropsychiatry Section, Department of Psychiatry, University of Pennsylvania, Philadelphia PA 19104, USA
| | - Karthik Prabhakaran
- Neuropsychiatry Section, Department of Psychiatry, University of Pennsylvania, Philadelphia PA 19104, USA
| | - Mark A. Elliott
- Department of Radiology & Center for Magnetic and Optical Imaging, University of Pennsylvania Perelman School of Medicine, University of Pennsylvania, Philadelphia PA 19104, USA
| | - Paul J. Moberg
- Neuropsychiatry Section, Department of Psychiatry, University of Pennsylvania, Philadelphia PA 19104, USA
| | - Ruben C. Gur
- Neuropsychiatry Section, Department of Psychiatry, University of Pennsylvania, Philadelphia PA 19104, USA
| | - Raquel E. Gur
- Neuropsychiatry Section, Department of Psychiatry, University of Pennsylvania, Philadelphia PA 19104, USA
| | - Ravinder Reddy
- Department of Radiology & Center for Magnetic and Optical Imaging, University of Pennsylvania Perelman School of Medicine, University of Pennsylvania, Philadelphia PA 19104, USA
| | - Bruce I. Turetsky
- Neuropsychiatry Section, Department of Psychiatry, University of Pennsylvania, Philadelphia PA 19104, USA
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Zhang XY, Wang F, Li H, Xu J, Gochberg DF, Gore JC, Zu Z. CEST imaging of fast exchanging amine pools with corrections for competing effects at 9.4 T. NMR IN BIOMEDICINE 2017; 30:10.1002/nbm.3715. [PMID: 28272785 PMCID: PMC5490838 DOI: 10.1002/nbm.3715] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 01/31/2017] [Accepted: 02/01/2017] [Indexed: 05/08/2023]
Abstract
Chemical exchange saturation transfer (CEST) imaging of fast exchanging amine protons at 3 ppm offset from the water resonant frequency is of practical interest, but quantification of fast exchanging pools by CEST is challenging. To effectively saturate fast exchanging protons, high irradiation powers need to be applied, but these may cause significant direct water saturation as well as non-specific semi-solid magnetization transfer (MT) effects, and thus decrease the specificity of the measured signal. In addition, the CEST signal may depend on the water longitudinal relaxation time (T1w ), which likely varies between tissues and with pathology, further reducing specificity. Previously, an analysis of the asymmetry of saturation effects (MTRasym ) has been commonly used to quantify fast exchanging amine CEST signals. However, our results show that MTRasym is greatly affected by the above factors, as well as asymmetric MT and nuclear Overhauser enhancement (NOE) effects. Here, we instead applied a relatively more specific inverse analysis method, named AREX (apparent exchange-dependent relaxation), that has previously been applied only to slow and intermediate exchanging solutes. Numerical simulations and controlled phantom experiments show that, although MTRasym depends on T1w and semi-solid content, AREX acquired in steady state does not, which suggests that AREX is more specific than MTRasym . By combining with a fitting approach instead of using the asymmetric analysis to obtain reference signals, AREX can also avoid contaminations from asymmetric MT and NOE effects. Animal experiments show that these two quantification methods produce differing contrasts between tumors and contralateral normal tissues in rat brain tumor models, suggesting that conventional MTRasym applied in vivo may be influenced by variations in T1w , semi-solid content, or NOE effect. Thus, the use of MTRasym may lead to misinterpretation, while AREX with corrections for competing effects likely enhances the specificity and accuracy of quantification to fast exchanging pools.
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Affiliation(s)
- Xiao-Yong Zhang
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Feng Wang
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Hua Li
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Junzhong Xu
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA
- Deparment of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee, USA
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA
| | - Daniel F. Gochberg
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA
- Deparment of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee, USA
| | - John C. Gore
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA
- Deparment of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee, USA
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA
- Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
| | - Zhongliang Zu
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA
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Salzillo TC, Hu J, Nguyen L, Whiting N, Lee J, Weygand J, Dutta P, Pudakalakatti S, Millward NZ, Gammon ST, Lang FF, Heimberger AB, Bhattacharya PK. Interrogating Metabolism in Brain Cancer. Magn Reson Imaging Clin N Am 2017; 24:687-703. [PMID: 27742110 DOI: 10.1016/j.mric.2016.07.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This article reviews existing and emerging techniques of interrogating metabolism in brain cancer from well-established proton magnetic resonance spectroscopy to the promising hyperpolarized metabolic imaging and chemical exchange saturation transfer and emerging techniques of imaging inflammation. Some of these techniques are at an early stage of development and clinical trials are in progress in patients to establish the clinical efficacy. It is likely that in vivo metabolomics and metabolic imaging is the next frontier in brain cancer diagnosis and assessing therapeutic efficacy; with the combined knowledge of genomics and proteomics a complete understanding of tumorigenesis in brain might be achieved.
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Affiliation(s)
- Travis C Salzillo
- Department of Cancer Systems Imaging, MD Anderson Cancer Center, The University of Texas, Houston, TX, USA; The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Jingzhe Hu
- Department of Cancer Systems Imaging, MD Anderson Cancer Center, The University of Texas, Houston, TX, USA; Department of Bioengineering, Rice University, Houston, TX, USA
| | - Linda Nguyen
- The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Nicholas Whiting
- Department of Cancer Systems Imaging, MD Anderson Cancer Center, The University of Texas, Houston, TX, USA
| | - Jaehyuk Lee
- Department of Cancer Systems Imaging, MD Anderson Cancer Center, The University of Texas, Houston, TX, USA
| | - Joseph Weygand
- Department of Cancer Systems Imaging, MD Anderson Cancer Center, The University of Texas, Houston, TX, USA; The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Prasanta Dutta
- Department of Cancer Systems Imaging, MD Anderson Cancer Center, The University of Texas, Houston, TX, USA
| | - Shivanand Pudakalakatti
- Department of Cancer Systems Imaging, MD Anderson Cancer Center, The University of Texas, Houston, TX, USA
| | - Niki Zacharias Millward
- Department of Cancer Systems Imaging, MD Anderson Cancer Center, The University of Texas, Houston, TX, USA
| | - Seth T Gammon
- Department of Cancer Systems Imaging, MD Anderson Cancer Center, The University of Texas, Houston, TX, USA
| | - Frederick F Lang
- Department of Neurosurgery, MD Anderson Cancer Center, The University of Texas, Houston, TX, USA
| | - Amy B Heimberger
- Department of Neurosurgery, MD Anderson Cancer Center, The University of Texas, Houston, TX, USA
| | - Pratip K Bhattacharya
- Department of Cancer Systems Imaging, MD Anderson Cancer Center, The University of Texas, Houston, TX, USA; The University of Texas Health Science Center at Houston, Houston, TX, USA.
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Bonvento G, Valette J, Flament J, Mochel F, Brouillet E. Imaging and spectroscopic approaches to probe brain energy metabolism dysregulation in neurodegenerative diseases. J Cereb Blood Flow Metab 2017; 37:1927-1943. [PMID: 28276944 PMCID: PMC5464722 DOI: 10.1177/0271678x17697989] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 01/10/2017] [Accepted: 02/06/2017] [Indexed: 12/14/2022]
Abstract
Changes in energy metabolism are generally considered to play an important role in neurodegenerative diseases such as Alzheimer's, Parkinson's, and Huntington's diseases. Whether these changes are causal or simply a part of self-defense mechanisms is a matter of debate. Furthermore, energy defects have often been discussed solely in the context of their probable neuronal origin without considering the cellular heterogeneity of the brain. Recent data point towards the existence of a tri-cellular compartmentation of brain energy metabolism between neurons, astrocytes, and oligodendrocytes, each cell type having a distinctive metabolic profile. Still, the number of methods to follow energy metabolism in patients is extremely limited and existing clinical techniques are blind to most cellular processes. There is a need to better understand how brain energy metabolism is regulated in health and disease through experiments conducted at different scales in animal models to implement new methods in the clinical setting. The purpose of this review is to offer a brief overview of the broad spectrum of methodological approaches that have emerged in recent years to probe energy metabolism in more detail. We conclude that multi-modal neuroimaging is needed to follow non-cell autonomous energy metabolism dysregulation in neurodegenerative diseases.
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Affiliation(s)
- Gilles Bonvento
- Commissariat à l’Energie Atomique et aux Energies Alternatives (CEA), Département de la Recherche Fondamentale (DRF), Institut d’Imagerie Biomédicale (I2BM), Molecular Imaging Research Center (MIRCen), CNRS UMR 9199, Université Paris-Sud, Université Paris-Saclay, Fontenay-aux-Roses, France
| | - Julien Valette
- Commissariat à l’Energie Atomique et aux Energies Alternatives (CEA), Département de la Recherche Fondamentale (DRF), Institut d’Imagerie Biomédicale (I2BM), Molecular Imaging Research Center (MIRCen), CNRS UMR 9199, Université Paris-Sud, Université Paris-Saclay, Fontenay-aux-Roses, France
| | - Julien Flament
- Commissariat à l’Energie Atomique et aux Energies Alternatives (CEA), Département de la Recherche Fondamentale (DRF), Institut d’Imagerie Biomédicale (I2BM), Molecular Imaging Research Center (MIRCen), CNRS UMR 9199, Université Paris-Sud, Université Paris-Saclay, Fontenay-aux-Roses, France
- INSERM US 27, Molecular Imaging Research Center (MIRCen), Fontenay-aux-Roses, France
| | - Fanny Mochel
- INSERM U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Université Paris 6, Institut du Cerveau et de la Moelle épinière, Paris, France
- Department of Genetics, AP-HP Hôpital Pitié-Salpêtrière, Paris, France
- University Pierre and Marie Curie, Neurometabolic Research Group, Paris, France
| | - Emmanuel Brouillet
- Commissariat à l’Energie Atomique et aux Energies Alternatives (CEA), Département de la Recherche Fondamentale (DRF), Institut d’Imagerie Biomédicale (I2BM), Molecular Imaging Research Center (MIRCen), CNRS UMR 9199, Université Paris-Sud, Université Paris-Saclay, Fontenay-aux-Roses, France
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Bagga P, Haris M, D'Aquilla K, Wilson NE, Marincola FM, Schnall MD, Hariharan H, Reddy R. Non-caloric sweetener provides magnetic resonance imaging contrast for cancer detection. J Transl Med 2017; 15:119. [PMID: 28558795 PMCID: PMC5450413 DOI: 10.1186/s12967-017-1221-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Accepted: 05/19/2017] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Image contrast enhanced by exogenous contrast agents plays a crucial role in the early detection, characterization, and determination of the precise location of cancers. Here, we investigate the feasibility of using a non-nutritive sweetener, sucralose (commercial name, Splenda), as magnetic resonance imaging (MRI) contrast agent for cancer studies. METHODS High-resolution nuclear-magnetic-resonance spectroscopy and MR studies on sucralose solution phantom were performed to detect the chemical exchange saturation transfer (CEST) property of sucralose hydroxyl protons with bulk water (sucCEST). For the animal experiments, female Fisher rats (F344/NCR) were used to generate 9L-gliosarcoma model. MRI with CEST experiments were performed on anesthetized rats at 9.4 T MR scanner. Following the baseline CEST scans, sucralose solution was intravenously administered in control and tumor bearing rats. CEST acquisitions were continued during and following the administration of sucralose. Following the sucCEST, Gadolinium-diethylenetriamine pentaacetic acid was injected to perform Gd-enhanced imaging for visualizing the tumor. RESULTS The sucCEST contrast in vitro was found to correlate positively with the sucralose concentration and negatively with the pH, indicating the potential of this technique in cancer imaging. In a control animal, the CEST contrast from the brain was found to be unaffected following the administration of sucralose, demonstrating its blood-brain barrier impermeability. In a 9L glioma model, enhanced localized sucCEST contrast in the tumor region was detected while the unaffected brain region showed unaltered CEST effect implying the specificity of sucralose toward the tumorous tissue. The CEST asymmetry plots acquired from the tumor region before and after the sucralose infusion showed elevation of asymmetry at 1 ppm, pointing towards the role of sucralose in increased contrast. CONCLUSIONS We show the feasibility of using sucralose and sucCEST in study of preclinical models of cancer. This study paves the way for the potential development of sucralose and other sucrose derivatives as contrast agents for clinical MRI applications.
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Affiliation(s)
- Puneet Bagga
- Department of Radiology, Center for Magnetic Resonance and Optical Imaging, Perelman School of Medicine, University of Pennsylvania, 422 Curie Blvd, B1-Stellar-Chance Laboratories, Philadelphia, PA, USA
| | - Mohammad Haris
- Research Branch, Sidra Medical and Research Center, Doha, Qatar
| | - Kevin D'Aquilla
- Department of Radiology, Center for Magnetic Resonance and Optical Imaging, Perelman School of Medicine, University of Pennsylvania, 422 Curie Blvd, B1-Stellar-Chance Laboratories, Philadelphia, PA, USA
| | - Neil E Wilson
- Department of Radiology, Center for Magnetic Resonance and Optical Imaging, Perelman School of Medicine, University of Pennsylvania, 422 Curie Blvd, B1-Stellar-Chance Laboratories, Philadelphia, PA, USA
| | | | - Mitchell D Schnall
- Department of Radiology, Center for Magnetic Resonance and Optical Imaging, Perelman School of Medicine, University of Pennsylvania, 422 Curie Blvd, B1-Stellar-Chance Laboratories, Philadelphia, PA, USA
| | - Hari Hariharan
- Department of Radiology, Center for Magnetic Resonance and Optical Imaging, Perelman School of Medicine, University of Pennsylvania, 422 Curie Blvd, B1-Stellar-Chance Laboratories, Philadelphia, PA, USA
| | - Ravinder Reddy
- Department of Radiology, Center for Magnetic Resonance and Optical Imaging, Perelman School of Medicine, University of Pennsylvania, 422 Curie Blvd, B1-Stellar-Chance Laboratories, Philadelphia, PA, USA.
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van Zijl PCM, Lam WW, Xu J, Knutsson L, Stanisz GJ. Magnetization Transfer Contrast and Chemical Exchange Saturation Transfer MRI. Features and analysis of the field-dependent saturation spectrum. Neuroimage 2017; 168:222-241. [PMID: 28435103 DOI: 10.1016/j.neuroimage.2017.04.045] [Citation(s) in RCA: 206] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 04/18/2017] [Accepted: 04/19/2017] [Indexed: 11/30/2022] Open
Abstract
Magnetization Transfer Contrast (MTC) and Chemical Exchange Saturation Transfer (CEST) experiments measure the transfer of magnetization from molecular protons to the solvent water protons, an effect that becomes apparent as an MRI signal loss ("saturation"). This allows molecular information to be accessed with the enhanced sensitivity of MRI. In analogy to Magnetic Resonance Spectroscopy (MRS), these saturation data are presented as a function of the chemical shift of participating proton groups, e.g. OH, NH, NH2, which is called a Z-spectrum. In tissue, these Z-spectra contain the convolution of multiple saturation transfer effects, including nuclear Overhauser enhancements (NOEs) and chemical exchange contributions from protons in semi-solid and mobile macromolecules or tissue metabolites. As a consequence, their appearance depends on the magnetic field strength (B0) and pulse sequence parameters such as B1 strength, pulse shape and length, and interpulse delay, which presents a major problem for quantification and reproducibility of MTC and CEST effects. The use of higher B0 can bring several advantages. In addition to higher detection sensitivity (signal-to-noise ratio, SNR), both MTC and CEST studies benefit from longer water T1 allowing the saturation transferred to water to be retained longer. While MTC studies are non-specific at any field strength, CEST specificity is expected to increase at higher field because of a larger chemical shift dispersion of the resonances of interest (similar to MRS). In addition, shifting to a slower exchange regime at higher B0 facilitates improved detection of the guanidinium protons of creatine and the inherently broad resonances of the amine protons in glutamate and the hydroxyl protons in myoinositol, glycogen, and glucosaminoglycans. Finally, due to the higher mobility of the contributing protons in CEST versus MTC, many new pulse sequences can be designed to more specifically edit for CEST signals and to remove MTC contributions.
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Affiliation(s)
- Peter C M van Zijl
- The Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA.
| | - Wilfred W Lam
- Physical Sciences, Sunnybrook Research Institute, Toronto, ON, Canada
| | - Jiadi Xu
- The Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Linda Knutsson
- The Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Medical Radiation Physics, Lund University, Lund, Sweden
| | - Greg J Stanisz
- Physical Sciences, Sunnybrook Research Institute, Toronto, ON, Canada; Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada; Department of Neurosurgery and Pediatric Neurosurgery, Medical University of Lublin, Lublin, Poland.
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Crescenzi R, DeBrosse C, Nanga RP, Byrne MD, Krishnamoorthy G, D’Aquilla K, Nath H, Morales KH, Iba M, Hariharan H, Lee VM, Detre JA, Reddy R. Longitudinal imaging reveals subhippocampal dynamics in glutamate levels associated with histopathologic events in a mouse model of tauopathy and healthy mice. Hippocampus 2017; 27:285-302. [PMID: 27997993 PMCID: PMC5396955 DOI: 10.1002/hipo.22693] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 12/02/2016] [Accepted: 12/02/2016] [Indexed: 11/08/2022]
Abstract
Tauopathies are neurodegenerative disorders characterized by abnormal intracellular aggregates of tau protein, and include Alzheimer's disease, corticobasal degeneration, frontotemporal dementia, and traumatic brain injury. Glutamate metabolism is altered in neurodegenerative disorders manifesting in higher or lower concentrations of glutamate, its transporters or receptors. Previously, glutamate chemical exchange saturation transfer (GluCEST) magnetic resonance imaging (MRI) demonstrated that glutamate levels are reduced in regions of synapse loss in the hippocampus of a mouse model of late-stage tauopathy. We performed a longitudinal GluCEST imaging experiment paired with a cross-sectional study of histologic markers of tauopathy to determine whether (1) early GluCEST changes are associated with synapse loss before volume loss occurs in the hippocampus, and whether (2) subhippocampal dynamics in GluCEST are associated with histopathologic events related to glutamate alterations in tauopathy. Live imaging of the hippocampus in three serial slices was performed without exogenous contrast agents, and subregions were segmented based on a k-means cluster model. Subregions of the hippocampus were analyzed (cornu ammonis CA1, CA3, dentate gyrus DG, and ventricle) in order to associate local MRI-observable changes in glutamate with histological measures of glial cell proliferation (GFAP), synapse density (synaptophysin, VGlut1) and glutamate receptor (NMDA-NR1) levels. Early differences in GluCEST between healthy and tauopathy mice were measured in the CA1 and DG subregions (30% reduction, P ≤ 0.001). Synapse density was also significantly reduced in every subregion of the hippocampus in tauopathy mice by 6 months. Volume was not significantly reduced in any subregion until 13 months. Further, a gradient in glutamate levels was observed in vivo along hippocampal axes that became polarized as tauopathy progressed. Dynamics in hippocampal glutamate levels throughout lifetime were most closely correlated with combined changes in synaptophysin and GFAP, indicating that GluCEST imaging may be a surrogate marker of glutamate concentration in glial cells and at the synaptic level. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Rachelle Crescenzi
- Department of Biochemistry & Molecular Biophysics (BMB), University of Pennsylvania, Philadelphia, PA, USA
- Center for Magnetic Resonance and Optical Imaging (CMROI), University of Pennsylvania, Philadelphia, PA, USA
| | - Catherine DeBrosse
- Department of Biochemistry & Molecular Biophysics (BMB), University of Pennsylvania, Philadelphia, PA, USA
- Center for Magnetic Resonance and Optical Imaging (CMROI), University of Pennsylvania, Philadelphia, PA, USA
| | - Ravi P.R. Nanga
- Center for Magnetic Resonance and Optical Imaging (CMROI), University of Pennsylvania, Philadelphia, PA, USA
| | - Matthew D. Byrne
- Center for Neurodegenerative Disease Research (CNDR), University of Pennsylvania, Philadelphia, PA, USA
| | - Guruprasad Krishnamoorthy
- Center for Magnetic Resonance and Optical Imaging (CMROI), University of Pennsylvania, Philadelphia, PA, USA
| | - Kevin D’Aquilla
- Center for Magnetic Resonance and Optical Imaging (CMROI), University of Pennsylvania, Philadelphia, PA, USA
| | - Hari Nath
- Center for Magnetic Resonance and Optical Imaging (CMROI), University of Pennsylvania, Philadelphia, PA, USA
| | - Knashawn H. Morales
- Department of Biostatistics and Epidemiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Michiyo Iba
- Center for Neurodegenerative Disease Research (CNDR), University of Pennsylvania, Philadelphia, PA, USA
| | - Hari Hariharan
- Center for Magnetic Resonance and Optical Imaging (CMROI), University of Pennsylvania, Philadelphia, PA, USA
| | - Virginia M.Y Lee
- Center for Neurodegenerative Disease Research (CNDR), University of Pennsylvania, Philadelphia, PA, USA
| | - John A. Detre
- Center for Functional Neuroimaging (CfN), University of Pennsylvania, Philadelphia, PA, USA
| | - Ravinder Reddy
- Center for Magnetic Resonance and Optical Imaging (CMROI), University of Pennsylvania, Philadelphia, PA, USA
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