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Hassel B, Sørnes K, Elsais A, Cordero PR, Frøland AS, Rise F. Glyceraldehyde metabolism in mouse brain and the entry of blood-borne glyceraldehyde into the brain. J Neurochem 2024; 168:2868-2879. [PMID: 38922704 DOI: 10.1111/jnc.16158] [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: 01/26/2024] [Revised: 06/10/2024] [Accepted: 06/11/2024] [Indexed: 06/28/2024]
Abstract
D-Glyceraldehyde, a reactive aldehyde metabolite of fructose and glucose, is neurotoxic in vitro by forming advanced glycation end products (AGEs) with neuronal proteins. In Alzheimer's disease brains, glyceraldehyde-containing AGEs have been detected intracellularly and in extracellular plaques. However, little information exists on how the brain handles D-glyceraldehyde metabolically or if glyceraldehyde crosses the blood-brain barrier from the circulation into the brain. We injected [U-13C]-D-glyceraldehyde intravenously into awake mice and analyzed extracts of serum and brain by 13C nuclear magnetic resonance spectroscopy. 13C-Labeling of brain lactate and glutamate indicated passage of D-glyceraldehyde from blood to brain and glycolytic and oxidative D-glyceraldehyde metabolism in brain cells. 13C-Labeling of serum glucose and lactate through hepatic metabolism of [U-13C]-D-glyceraldehyde could not explain the formation of 13C-labeled lactate and glutamate in the brain. Cerebral glyceraldehyde dehydrogenase and reductase activities, leading to the formation of D-glycerate and glycerol, respectively, were 0.27-0.28 nmol/mg/min; triokinase, which phosphorylates D-glyceraldehyde to D-glyceraldehyde-3-phosphate, has been demonstrated previously at low levels. Thus, D-glyceraldehyde metabolism toward glycolysis could proceed both through D-glycerate, glycerol, and D-glyceraldehyde-3-phosphate. The aldehyde group of D-glyceraldehyde was overwhelmingly hydrated into a diol in aqueous solution, but the diol dehydration rate greatly exceeded glyceraldehyde metabolism and did not restrict it. We conclude that (1) D-glyceraldehyde crosses the blood-brain barrier, and so blood-borne glyceraldehyde could contribute to AGE formation in the brain, (2) glyceraldehyde is taken up and metabolized by brain cells. Metabolism thus constitutes a detoxification mechanism for this reactive aldehyde, a mechanism that may be compromised in disease states.
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Affiliation(s)
- Bjørnar Hassel
- Department of Neurohabilitation, Oslo University Hospital, Oslo, Norway
- Norwegian Defence Research Establishment (FFI), Kjeller, Norway
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | | | - Ahmed Elsais
- Department of Neurology, Oslo University Hospital, Oslo, Norway
| | | | - Anne Sofie Frøland
- Department of Neurohabilitation, Oslo University Hospital, Oslo, Norway
- Department of Chemistry, University of Oslo, Norway
| | - Frode Rise
- Department of Chemistry, University of Oslo, Norway
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2
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Carbon sources and pathways for citrate secreted by human prostate cancer cells determined by NMR tracing and metabolic modeling. Proc Natl Acad Sci U S A 2022; 119:e2024357119. [PMID: 35353621 PMCID: PMC9168453 DOI: 10.1073/pnas.2024357119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The human prostate accumulates high luminal citrate levels to serve sperm viability. There is only indirect qualitative evidence about metabolic pathways and carbon sources maintaining these levels. Human citrate-secreting prostate cancer cells were supplied with 13C-labeled substrates, and NMR spectra of extracellular fluid were recorded. We report absolute citrate production rates of prostate cells and direct evidence that glucose is the main carbon source for secreted citrate. Pyruvate carboxylase provides sufficient anaplerotic carbons to support citrate secretion. Glutamine carbons exchange with carbons for secreted citrate but are likely not involved in its net synthesis. Moreover, we developed metabolic models employing the 13C distribution in extracellular citrate as input to assess intracellular pathways followed by carbons toward citrate. Prostate epithelial cells have the unique capacity to secrete large amounts of citrate, but the carbon sources and metabolic pathways that maintain this production are not well known. We mapped potential pathways for citrate carbons in the human prostate cancer metastasis cell lines LNCaP and VCaP, for which we first established that they secrete citrate (For LNCaP 5.6 ± 0.9 nmol/h per 106 cells). Using 13C-labeled substrates, we traced the incorporation of 13C into citrate by NMR of extracellular fluid. Our results provide direct evidence that glucose is a main carbon source for secreted citrate. We also demonstrate that carbons from supplied glutamine flow via oxidative Krebs cycle and reductive carboxylation routes to positions in secreted citrate but likely do not contribute to its net synthesis. The potential anaplerotic carbon sources aspartate and asparagine did not contribute to citrate carbons. We developed a quantitative metabolic model employing the 13C distribution in extracellular citrate after 13C glucose and pyruvate application to assess intracellular pathways of carbons for secreted citrate. From this model, it was estimated that in LNCaP about 21% of pyruvate entering the Krebs cycle is converted via pyruvate carboxylase as an anaplerotic route at a rate more than sufficient to compensate carbon loss of this cycle by citrate secretion. This model provides an estimation of the fraction of molecules, including citrate, leaving the Krebs cycle at every turn. The measured ratios of 13C atoms at different positions in extracellular citrate may serve as biomarkers for (malignant) epithelial cell metabolism.
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3
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Guo M, Fang Y, Zhu J, Chen C, Zhang Z, Tian X, Xiang H, Manyande A, Ehsanifar M, Jafari AJ, Xu F, Wang J, Peng M. Investigation of metabolic kinetics in different brain regions of awake rats using the [ 1H- 13C]-NMR technique. J Pharm Biomed Anal 2021; 204:114240. [PMID: 34246879 DOI: 10.1016/j.jpba.2021.114240] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 06/30/2021] [Accepted: 07/02/2021] [Indexed: 12/12/2022]
Abstract
Energy metabolism and neurotransmission are necessary for sustaining normal life activities. Hence, neurological or psychiatric disorders are always associated with changes in neurotransmitters and energy metabolic states in the brain. Most studies have only focused on the most important neurotransmitters, particularly GABA and Glu, however, other metabolites such as NAA and aspartate which are also very important for cerebral function are rarely investigated. In this study, most of the metabolic kinetics information of different brain regions was investigated in awake rats using the [1H-13C]-NMR technique. Briefly, rats (n = 8) were infused [1-13C] glucose through the tail vein for two minutes. After 20 min of glucose metabolism, the animals were sacrificed and the brain tissue was extracted and treated. Utilizing the 1H observed/13C-edited nuclear magnetic resonance (POCE-NMR), the enrichment of neurochemicals was detected which reflected the metabolic changes in different brain regions and the metabolic connections between neurons and glial cells in the brain. The results suggest that the distribution of every metabolite differed from every brain region and the metabolic rate of NAA was relatively low at 8.64 ± 2.37 μmol/g/h. In addition, there were some correlations between several 13C enriched metabolites, such as Glu4-Gln4 (p = 0.062), Glu4-GABA2 (p < 0.01), Glx2-Glx3 (p < 0.001), Asp3-NAA3 (p < 0.001). This correlativity reflects the signal transmission between astrocytes and neurons, as well as the potential interaction between energy metabolism and neurotransmission. In conclusion, the current study systematically demonstrated the metabolic kinetics in the brain which shed light on brain functions and the mechanisms of various pathophysiological states.
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Affiliation(s)
- Meimei Guo
- Department of Anesthesiology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, 430071, PR China; Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences-Wuhan National Laboratory for Optoelectronics, 430071, Wuhan, PR China
| | - Yuanyuan Fang
- Department of Anesthesiology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, 430071, PR China; Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences-Wuhan National Laboratory for Optoelectronics, 430071, Wuhan, PR China
| | - Jinpiao Zhu
- Department of Anesthesiology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, 430071, PR China; Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences-Wuhan National Laboratory for Optoelectronics, 430071, Wuhan, PR China
| | - Chang Chen
- Department of Anesthesiology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, 430071, PR China
| | - Zongze Zhang
- Department of Anesthesiology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, 430071, PR China
| | - Xuebi Tian
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430070, PR China
| | - Hongbing Xiang
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430070, PR China
| | - Anne Manyande
- School of Human and Social Sciences, University of West London, London, UK
| | - Mojtaba Ehsanifar
- Department of Environmental Health Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran
| | - Ahmad Jonidi Jafari
- Department of Environmental Health Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran
| | - Fuqiang Xu
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences-Wuhan National Laboratory for Optoelectronics, 430071, Wuhan, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Jie Wang
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences-Wuhan National Laboratory for Optoelectronics, 430071, Wuhan, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China; Hebei Provincial Key Laboratory of Basic Medicine for Diabetes, 2nd Hospital of Shijiazhuang, Shijiazhuang, Hebei, 050051, PR China.
| | - Mian Peng
- Department of Anesthesiology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, 430071, PR China.
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Abdik E, Çakır T. Systematic investigation of mouse models of Parkinson's disease by transcriptome mapping on a brain-specific genome-scale metabolic network. Mol Omics 2021; 17:492-502. [PMID: 34370801 DOI: 10.1039/d0mo00135j] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Genome-scale metabolic networks enable systemic investigation of metabolic alterations caused by diseases by providing interpretation of omics data. Although Mus musculus (mouse) is one of the most commonly used model organisms for neurodegenerative diseases, a brain-specific metabolic network model of mice has not yet been reconstructed. Here we reconstructed the first brain-specific metabolic network model of mice, iBrain674-Mm, by a homology-based approach, which consisted of 992 reactions controlled by 674 genes and distributed over 48 pathways. We validated the newly reconstructed network model by showing that it predicts healthy resting-state metabolic phenotypes of mouse brain compatible with the literature. We later used iBrain674-Mm to interpret various experimental mouse models of Parkinson's Disease (PD) at the transcriptome level. To this end, we applied a constraint-based modelling based biomarker prediction method called TIMBR (Transcriptionally Inferred Metabolic Biomarker Response) to predict altered metabolite production from transcriptomic data. Systemic analysis of seven different PD mouse models by TIMBR showed that the neuronal levels of glutamate, lactate, creatine phosphate, neuronal acetylcholine, bilirubin and formate increased in most of the PD mouse models, whereas the levels of melatonin, epinephrine, astrocytic formate and astrocytic bilirubin decreased. Although most of the predictions were consistent with the literature, there were some inconsistencies among different PD mouse models, signifying that there is no perfect experimental model to reflect PD metabolism. The newly reconstructed brain-specific genome-scale metabolic network model of mice can make important contributions to the interpretation and development of experimental mouse models of PD and other neurodegenerative diseases.
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Affiliation(s)
- Ecehan Abdik
- Department of Bioengineering, Gebze Technical University, Kocaeli, Turkey.
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Cherix A, Donati G, Lizarbe B, Lanz B, Poitry-Yamate C, Lei H, Gruetter R. Excitatory/inhibitory neuronal metabolic balance in mouse hippocampus upon infusion of [U- 13C 6]glucose. J Cereb Blood Flow Metab 2021; 41:282-297. [PMID: 32151224 PMCID: PMC8370000 DOI: 10.1177/0271678x20910535] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Hippocampus plays a critical role in linking brain energetics and behavior typically associated to stress exposure. In this study, we aimed to simultaneously assess excitatory and inhibitory neuronal metabolism in mouse hippocampus in vivo by applying 18FDG-PET and indirect 13C magnetic resonance spectroscopy (1H-[13C]-MRS) at 14.1 T upon infusion of uniformly 13C-labeled glucose ([U-13C6]Glc). Improving the spectral fitting by taking into account variable decoupling efficiencies of [U-13C6]Glc and refining the compartmentalized model by including two γ-aminobutyric acid (GABA) pools permit us to evaluate the relative contributions of glutamatergic and GABAergic metabolism to total hippocampal neuroenergetics. We report that GABAergic activity accounts for ∼13% of total neurotransmission (VNT) and ∼27% of total neuronal TCA cycle (VTCA) in mouse hippocampus suggesting a higher VTCA/VNT ratio for inhibitory neurons compared to excitatory neurons. Finally, our results provide new strategies and tools for bringing forward the developments and applications of 13C-MRS in specific brain regions of small animals.
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Affiliation(s)
- Antoine Cherix
- Laboratory for Functional and Metabolic Imaging, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Guillaume Donati
- Laboratory for Functional and Metabolic Imaging, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Blanca Lizarbe
- Laboratory for Functional and Metabolic Imaging, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Instituto de Investigaciones Biomedicas "Alberto Sols", CSIC-UAM, Madrid, Spain
| | - Bernard Lanz
- Laboratory for Functional and Metabolic Imaging, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Sir Peter Mansfield Imaging Centre (SPMIC), School of Medicine, University of Nottingham, Nottingham, UK
| | - Carole Poitry-Yamate
- Laboratory for Functional and Metabolic Imaging, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Hongxia Lei
- Center for Biomedical Imaging (CIBM-AIT), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Rolf Gruetter
- Laboratory for Functional and Metabolic Imaging, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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6
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Cherix A, Sonti R, Lanz B, Lei H. In Vivo Metabolism of [1,6- 13C 2]Glucose Reveals Distinct Neuroenergetic Functionality between Mouse Hippocampus and Hypothalamus. Metabolites 2021; 11:metabo11010050. [PMID: 33445747 PMCID: PMC7828183 DOI: 10.3390/metabo11010050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 01/06/2021] [Accepted: 01/08/2021] [Indexed: 12/27/2022] Open
Abstract
Glucose is a major energy fuel for the brain, however, less is known about specificities of its metabolism in distinct cerebral areas. Here we examined the regional differences in glucose utilization between the hypothalamus and hippocampus using in vivo indirect 13C magnetic resonance spectroscopy (1H-[13C]-MRS) upon infusion of [1,6-13C2]glucose. Using a metabolic flux analysis with a 1-compartment mathematical model of brain metabolism, we report that compared to hippocampus, hypothalamus shows higher levels of aerobic glycolysis associated with a marked gamma-aminobutyric acid-ergic (GABAergic) and astrocytic metabolic dependence. In addition, our analysis suggests a higher rate of ATP production in hypothalamus that is accompanied by an excess of cytosolic nicotinamide adenine dinucleotide (NADH) production that does not fuel mitochondria via the malate-aspartate shuttle (MAS). In conclusion, our results reveal significant metabolic differences, which might be attributable to respective cell populations or functional features of both structures.
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Affiliation(s)
- Antoine Cherix
- Laboratory of Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland; (A.C.); (R.S.); (B.L.)
| | - Rajesh Sonti
- Laboratory of Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland; (A.C.); (R.S.); (B.L.)
| | - Bernard Lanz
- Laboratory of Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland; (A.C.); (R.S.); (B.L.)
| | - Hongxia Lei
- Animal Imaging and Technology (AIT), Center for Biomedical Imaging (CIBM), Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
- Faculty of Medicine, University of Geneva, CH-1206 Geneva, Switzerland
- Correspondence:
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7
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Lanz B, Abaei A, Braissant O, Choi IY, Cudalbu C, Henry PG, Gruetter R, Kara F, Kantarci K, Lee P, Lutz NW, Marjańska M, Mlynárik V, Rasche V, Xin L, Valette J. Magnetic resonance spectroscopy in the rodent brain: Experts' consensus recommendations. NMR IN BIOMEDICINE 2020; 34:e4325. [PMID: 33565219 PMCID: PMC9429976 DOI: 10.1002/nbm.4325] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 03/29/2020] [Accepted: 04/30/2020] [Indexed: 05/21/2023]
Abstract
In vivo MRS is a non-invasive measurement technique used not only in humans, but also in animal models using high-field magnets. MRS enables the measurement of metabolite concentrations as well as metabolic rates and their modifications in healthy animals and disease models. Such data open the way to a deeper understanding of the underlying biochemistry, related disturbances and mechanisms taking place during or prior to symptoms and tissue changes. In this work, we focus on the main preclinical 1H, 31P and 13C MRS approaches to study brain metabolism in rodent models, with the aim of providing general experts' consensus recommendations (animal models, anesthesia, data acquisition protocols). An overview of the main practical differences in preclinical compared with clinical MRS studies is presented, as well as the additional biochemical information that can be obtained in animal models in terms of metabolite concentrations and metabolic flux measurements. The properties of high-field preclinical MRS and the technical limitations are also described.
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Affiliation(s)
- Bernard Lanz
- Laboratory for Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
- Sir Peter Mansfield Imaging Centre, School of Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Alireza Abaei
- Core Facility Small Animal Imaging, Ulm University, Ulm, Germany
| | - Olivier Braissant
- Service of Clinical Chemistry, University of Lausanne and University Hospital of Lausanne, Lausanne, Switzerland
| | - In-Young Choi
- Department of Neurology, University of Kansas Medical Center, Kansas City, Kansas, US
| | - Cristina Cudalbu
- Centre d'Imagerie Biomedicale (CIBM), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Pierre-Gilles Henry
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, Minnesota, US
| | - Rolf Gruetter
- Laboratory for Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Firat Kara
- Department of Radiology, Mayo Clinic, Rochester, Minnesota, US
| | - Kejal Kantarci
- Department of Radiology, Mayo Clinic, Rochester, Minnesota, US
| | - Phil Lee
- Department of Radiology, University of Kansas Medical Center, Kansas City, Kansas, US
| | - Norbert W Lutz
- CNRS, CRMBM, Aix-Marseille University, Marseille, France
| | - Małgorzata Marjańska
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, Minnesota, US
| | - Vladimír Mlynárik
- High Field MR Centre, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Volker Rasche
- Core Facility Small Animal Imaging, Ulm University, Ulm, Germany
| | - Lijing Xin
- Centre d'Imagerie Biomedicale (CIBM), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Julien Valette
- Commissariat à l'Energie Atomique et aux Energies Alternatives, MIRCen, Fontenay-aux-Roses, France
- Neurodegenerative Diseases Laboratory, Centre National de la Recherche Scientifique, Université Paris-Sud, Université Paris-Saclay, UMR 9199, Fontenay-aux-Roses, France
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8
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Dobberthien BJ, Tessier AG, Stanislaus AE, Sawyer MB, Fallone BG, Yahya A. PRESS timings for resolving 13 C 4 -glutamate 1 H signal at 9.4 T: Demonstration in rat with uniformly labelled 13 C-glucose. NMR IN BIOMEDICINE 2019; 32:e4180. [PMID: 31518031 DOI: 10.1002/nbm.4180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 07/30/2019] [Accepted: 08/18/2019] [Indexed: 06/10/2023]
Abstract
MRS of 13 C4 -labelled glutamate (13 C4 -Glu) during an infusion of a carbon-13 (13 C)-labelled substrate, such as uniformly labelled glucose ([U-13 C6 ]-Glc), provides a measure of Glc metabolism. The presented work provides a single-shot indirect 13 C detection technique to quantify the approximately 2.51 ppm 13 C4 -Glu satellite proton (1 H) peak at 9.4 T. The methodology is an optimized point-resolved spectroscopy (PRESS) sequence that minimizes signal contamination from the strongly coupled protons of N-acetylaspartate (NAA), which resonate at approximately 2.49 ppm. J-coupling evolution of protons was characterized numerically and verified experimentally. A (TE1 , TE2 ) combination of (20 ms, 106 ms) was found to be suitable for minimizing NAA signal in the 2.51 ppm 1 H 13 C4 -Glu spectral region, while retaining the 13 C4 -Glu 1 H satellite peak. The efficacy of the technique was verified on phantom solutions and on two rat brains in vivo during an infusion of [U-13 C6 ]-Glc. LCModel was employed for analysis of the in vivo spectra to quantify the 2.51 ppm 1 H 13 C4 -Glu signal to obtain Glu C4 fractional enrichment time courses during the infusions. Cramér-Rao lower bounds of about 8% were obtained for the 2.51 ppm 13 C4 -Glu 1 H satellite peak with the optimal TE combination.
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Affiliation(s)
| | - Anthony G Tessier
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
- Department of Medical Physics, Cross Cancer Institute, Edmonton, Alberta, Canada
| | | | - Michael B Sawyer
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
| | - B Gino Fallone
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
- Department of Medical Physics, Cross Cancer Institute, Edmonton, Alberta, Canada
| | - Atiyah Yahya
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
- Department of Medical Physics, Cross Cancer Institute, Edmonton, Alberta, Canada
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9
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Syed MBJ, Fletcher AJ, Forsythe RO, Kaczynski J, Newby DE, Dweck MR, van Beek EJR. Emerging techniques in atherosclerosis imaging. Br J Radiol 2019; 92:20180309. [PMID: 31502858 PMCID: PMC6849665 DOI: 10.1259/bjr.20180309] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 08/14/2019] [Accepted: 08/27/2019] [Indexed: 12/13/2022] Open
Abstract
Atherosclerosis is a chronic immunomodulated disease that affects multiple vascular beds and results in a significant worldwide disease burden. Conventional imaging modalities focus on the morphological features of atherosclerotic disease such as the degree of stenosis caused by a lesion. Modern CT, MR and positron emission tomography scanners have seen significant improvements in the rapidity of image acquisition and spatial resolution. This has increased the scope for the clinical application of these modalities. Multimodality imaging can improve cardiovascular risk prediction by informing on the constituency and metabolic processes within the vessel wall. Specific disease processes can be targeted using novel biological tracers and "smart" contrast agents. These approaches have the potential to inform clinicians of the metabolic state of atherosclerotic plaque. This review will provide an overview of current imaging techniques for the imaging of atherosclerosis and how various modalities can provide information that enhances the depiction of basic morphology.
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Affiliation(s)
- Maaz BJ Syed
- British Heart Foundation Centre of Cardiovascular Science
| | | | | | | | | | - Marc R Dweck
- British Heart Foundation Centre of Cardiovascular Science
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10
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Lizarbe B, Cherix A, Duarte JMN, Cardinaux JR, Gruetter R. High-fat diet consumption alters energy metabolism in the mouse hypothalamus. Int J Obes (Lond) 2018; 43:1295-1304. [PMID: 30301962 DOI: 10.1038/s41366-018-0224-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 08/14/2018] [Accepted: 08/29/2018] [Indexed: 12/15/2022]
Abstract
BACKGROUND/OBJECTIVES High-fat diet consumption is known to trigger an inflammatory response in the hypothalamus, which has been characterized by an initial expression of pro-inflammatory genes followed by hypothalamic astrocytosis, microgliosis, and the appearance of neuronal injury markers. The specific effects of high-fat diet on hypothalamic energy metabolism and neurotransmission are however not yet known and have not been investigated before. SUBJECTS/METHODS We used 1H and 13C magnetic resonance spectroscopy (MRS) and immunofluorescence techniques to evaluate in vivo the consequences of high-saturated fat diet administration to mice, and explored the effects on hypothalamic metabolism in three mouse cohorts at different time points for up to 4 months. RESULTS We found that high-fat diet increases significantly the hypothalamic levels of glucose (P < 0.001), osmolytes (P < 0.001), and neurotransmitters (P < 0.05) from 2 months of diet, and alters the rates of metabolic (P < 0.05) and neurotransmission fluxes (P < 0.001), and the contribution of non-glycolytic substrates to hypothalamic metabolism (P < 0.05) after 10 weeks of high-fat feeding. CONCLUSIONS/INTERPRETATION We report changes that reveal a high-fat diet-induced alteration of hypothalamic metabolism and neurotransmission that is quantifiable by 1H and 13C MRS in vivo, and present the first evidence of the extension of the inflammation pathology to a localized metabolic imbalance.
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Affiliation(s)
- Blanca Lizarbe
- Laboratory of Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
| | - Antoine Cherix
- Laboratory of Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - João M N Duarte
- Laboratory of Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Department of Experimental Medical Science, Faculty of Medicine, Lund University, Lund, Sweden.,Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden
| | - Jean-René Cardinaux
- Center for Psychiatric Neuroscience (CNP), Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
| | - Rolf Gruetter
- Laboratory of Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Department of Radiology, University of Geneva, Geneva, Switzerland.,Department of Radiology, University of Lausanne, Lausanne, Switzerland
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11
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Lai M, Lanz B, Poitry-Yamate C, Romero JF, Berset CM, Cudalbu C, Gruetter R. In vivo 13C MRS in the mouse brain at 14.1 Tesla and metabolic flux quantification under infusion of [1,6- 13C 2]glucose. J Cereb Blood Flow Metab 2018; 38:1701-1714. [PMID: 29047296 PMCID: PMC6168901 DOI: 10.1177/0271678x17734101] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
In vivo 13C magnetic resonance spectroscopy (MRS) enables the investigation of cerebral metabolic compartmentation while, e.g. infusing 13C-labeled glucose. Metabolic flux analysis of 13C turnover previously yielded quantitative information of glutamate and glutamine metabolism in humans and rats, while the application to in vivo mouse brain remains exceedingly challenging. In the present study, 13C direct detection at 14.1 T provided highly resolved in vivo spectra of the mouse brain while infusing [1,6-13C2]glucose for up to 5 h. 13C incorporation to glutamate and glutamine C4, C3, and C2 and aspartate C3 were detected dynamically and fitted to a two-compartment model: flux estimation of neuron-glial metabolism included tricarboxylic acid cycle (TCA) flux in astrocytes (Vg = 0.16 ± 0.03 µmol/g/min) and neurons (VTCAn = 0.56 ± 0.03 µmol/g/min), pyruvate carboxylase activity (VPC = 0.041 ± 0.003 µmol/g/min) and neurotransmission rate (VNT = 0.084 ± 0.008 µmol/g/min), resulting in a cerebral metabolic rate of glucose (CMRglc) of 0.38 ± 0.02 µmol/g/min, in excellent agreement with that determined with concomitant 18F-fluorodeoxyglucose positron emission tomography (18FDG PET).We conclude that modeling of neuron-glial metabolism in vivo is accessible in the mouse brain from 13C direct detection with an unprecedented spatial resolution under [1,6-13C2]glucose infusion.
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Affiliation(s)
- Marta Lai
- 1 Laboratory for Functional and Metabolic Imaging (LIFMET), École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Bernard Lanz
- 1 Laboratory for Functional and Metabolic Imaging (LIFMET), École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Carole Poitry-Yamate
- 2 Center for Biomedical Imaging, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Jackeline F Romero
- 2 Center for Biomedical Imaging, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Corina M Berset
- 2 Center for Biomedical Imaging, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Cristina Cudalbu
- 2 Center for Biomedical Imaging, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Rolf Gruetter
- 1 Laboratory for Functional and Metabolic Imaging (LIFMET), École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,2 Center for Biomedical Imaging, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,3 Department of Radiology, University of Geneva, Geneva, Switzerland.,4 Department of Radiology, University of Lausanne, Lausanne, Switzerland
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12
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Harris T, Azar A, Sapir G, Gamliel A, Nardi-Schreiber A, Sosna J, Gomori JM, Katz-Brull R. Real-time ex-vivo measurement of brain metabolism using hyperpolarized [1- 13C]pyruvate. Sci Rep 2018; 8:9564. [PMID: 29934508 PMCID: PMC6014998 DOI: 10.1038/s41598-018-27747-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 06/11/2018] [Indexed: 12/19/2022] Open
Abstract
The ability to directly monitor in vivo brain metabolism in real time in a matter of seconds using the dissolution dynamic nuclear polarization technology holds promise to aid the understanding of brain physiology in health and disease. However, translating the hyperpolarized signal observed in the brain to cerebral metabolic rates is not straightforward, as the observed in vivo signals reflect also the influx of metabolites produced in the body, the cerebral blood volume, and the rate of transport across the blood brain barrier. We introduce a method to study rapid metabolism of hyperpolarized substrates in the viable rat brain slices preparation, an established ex vivo model of the brain. By retrospective evaluation of tissue motion and settling from analysis of the signal of the hyperpolarized [1-13C]pyruvate precursor, the T1s of the metabolites and their rates of production can be determined. The enzymatic rates determined here are in the range of those determined previously with classical biochemical assays and are in agreement with hyperpolarized metabolite relative signal intensities observed in the rodent brain in vivo.
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Affiliation(s)
- Talia Harris
- Department of Radiology, Hadassah-Hebrew University Medical Center, Jerusalem, 9112001, Israel
| | - Assad Azar
- Department of Radiology, Hadassah-Hebrew University Medical Center, Jerusalem, 9112001, Israel
| | - Gal Sapir
- Department of Radiology, Hadassah-Hebrew University Medical Center, Jerusalem, 9112001, Israel
| | - Ayelet Gamliel
- Department of Radiology, Hadassah-Hebrew University Medical Center, Jerusalem, 9112001, Israel
| | - Atara Nardi-Schreiber
- Department of Radiology, Hadassah-Hebrew University Medical Center, Jerusalem, 9112001, Israel
| | - Jacob Sosna
- Department of Radiology, Hadassah-Hebrew University Medical Center, Jerusalem, 9112001, Israel
| | - J Moshe Gomori
- Department of Radiology, Hadassah-Hebrew University Medical Center, Jerusalem, 9112001, Israel
| | - Rachel Katz-Brull
- Department of Radiology, Hadassah-Hebrew University Medical Center, Jerusalem, 9112001, Israel.
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13
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Lizarbe B, Lei H, Duarte JM, Lanz B, Cherix A, Gruetter R. Feasibility of in vivo measurement of glucose metabolism in the mouse hypothalamus by1H-[13C] MRS at 14.1T. Magn Reson Med 2018; 80:874-884. [DOI: 10.1002/mrm.27129] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 01/22/2018] [Accepted: 01/22/2018] [Indexed: 12/24/2022]
Affiliation(s)
- Blanca Lizarbe
- Laboratory of Functional and Metabolic Imaging (LIFMET), École Polytechnique Fédérale de Lausanne; Lausanne Switzerland
| | - Hongxia Lei
- Department of Radiology; University of Geneva, Geneva, Switzerland and Center for Biomedical Imaging (CIBM); Lausanne Switzerland
| | - Joao M.N. Duarte
- Laboratory of Functional and Metabolic Imaging (LIFMET), École Polytechnique Fédérale de Lausanne; Lausanne Switzerland
| | - Bernard Lanz
- Laboratory of Functional and Metabolic Imaging (LIFMET), École Polytechnique Fédérale de Lausanne; Lausanne Switzerland
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham; Nottingham United Kingdom
| | - Antoine Cherix
- Laboratory of Functional and Metabolic Imaging (LIFMET), École Polytechnique Fédérale de Lausanne; Lausanne Switzerland
| | - Rolf Gruetter
- Laboratory of Functional and Metabolic Imaging (LIFMET), École Polytechnique Fédérale de Lausanne; Lausanne Switzerland
- Department of Radiology; University of Geneva, Geneva, Switzerland and Center for Biomedical Imaging (CIBM); Lausanne Switzerland
- Department of Radiology; University of Lausanne; Lausanne Switzerland
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14
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Abstract
Magnetic Resonance Spectroscopy is a technique that has the capability of measuring metabolites in vivo and, in appropriate conditions, to infer its metabolic rates. The success of MRS depends a lot on its sensitivity, which limits the usage of X-nuclei MRS. However, technological developments and refinements in methods have made in vivo heteronuclear MRS possible in humans and in small animals. This chapter provides detailed descriptions of the main procedures needed to perform successful in vivo heteronuclear MRS experiments, with a particular focus on experimental setup in 13C MRS experiments in rodents.
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Affiliation(s)
- Blanca Lizarbe
- Laboratory for Functional and Metabolic Imaging (LIFMET), École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
| | - Antoine Cherix
- Laboratory for Functional and Metabolic Imaging (LIFMET), École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Rolf Gruetter
- Laboratory for Functional and Metabolic Imaging (LIFMET), École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Department of Radiology, University of Geneva, Geneva, Switzerland.,Department of Radiology, University of Lausanne, Lausanne, Switzerland
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15
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Lai M, Gruetter R, Lanz B. Progress towards in vivo brain 13C-MRS in mice: Metabolic flux analysis in small tissue volumes. Anal Biochem 2017; 529:229-244. [PMID: 28119064 DOI: 10.1016/j.ab.2017.01.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Revised: 01/19/2017] [Accepted: 01/20/2017] [Indexed: 01/08/2023]
Abstract
The combination of dynamic 13C MRS data under infusion of 13C-labelled substrates and compartmental models of cerebral metabolism enabled in vivo measurement of metabolic fluxes with a quantitative and distinct determination of cellular-specific activities. The non-invasive nature and the chemical specificity of the 13C dynamic data obtained in those tracer experiments makes it an attractive approach offering unique insights into cerebral metabolism. Genetically engineered mice present a wealth of disease models particularly interesting for the neuroscience community. Nevertheless, in vivo13C NMR studies of the mouse brain are only recently appearing in the field due to the numerous challenges linked to the small mouse brain volume and the difficulty to follow the mouse physiological parameters within the NMR system during the infusion experiment. This review will present the progresses in the quest for a higher in vivo13C signal-to-noise ratio up to the present state of the art techniques, which made it feasible to assess glucose metabolism in different regions of the mouse brain. We describe how experimental results were integrated into suitable compartmental models and how a deep understanding of cerebral metabolism depends on the reliable detection of 13C in the different molecules and carbon positions.
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Affiliation(s)
- Marta Lai
- Laboratory for Functional and Metabolic Imaging (LIFMET), École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
| | - Rolf Gruetter
- Laboratory for Functional and Metabolic Imaging (LIFMET), École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland; Department of Radiology, University of Geneva, 1205 Geneva, Switzerland; Department of Radiology, University of Lausanne, 1015 Lausanne, Switzerland
| | - Bernard Lanz
- Laboratory for Functional and Metabolic Imaging (LIFMET), École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland; Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom
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16
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Central Role of Glutamate Metabolism in the Maintenance of Nitrogen Homeostasis in Normal and Hyperammonemic Brain. Biomolecules 2016; 6:biom6020016. [PMID: 27023624 PMCID: PMC4919911 DOI: 10.3390/biom6020016] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 03/10/2016] [Accepted: 03/15/2016] [Indexed: 12/21/2022] Open
Abstract
Glutamate is present in the brain at an average concentration—typically 10–12 mM—far in excess of those of other amino acids. In glutamate-containing vesicles in the brain, the concentration of glutamate may even exceed 100 mM. Yet because glutamate is a major excitatory neurotransmitter, the concentration of this amino acid in the cerebral extracellular fluid must be kept low—typically µM. The remarkable gradient of glutamate in the different cerebral compartments: vesicles > cytosol/mitochondria > extracellular fluid attests to the extraordinary effectiveness of glutamate transporters and the strict control of enzymes of glutamate catabolism and synthesis in well-defined cellular and subcellular compartments in the brain. A major route for glutamate and ammonia removal is via the glutamine synthetase (glutamate ammonia ligase) reaction. Glutamate is also removed by conversion to the inhibitory neurotransmitter γ-aminobutyrate (GABA) via the action of glutamate decarboxylase. On the other hand, cerebral glutamate levels are maintained by the action of glutaminase and by various α-ketoglutarate-linked aminotransferases (especially aspartate aminotransferase and the mitochondrial and cytosolic forms of the branched-chain aminotransferases). Although the glutamate dehydrogenase reaction is freely reversible, owing to rapid removal of ammonia as glutamine amide, the direction of the glutamate dehydrogenase reaction in the brain in vivo is mainly toward glutamate catabolism rather than toward the net synthesis of glutamate, even under hyperammonemia conditions. During hyperammonemia, there is a large increase in cerebral glutamine content, but only small changes in the levels of glutamate and α-ketoglutarate. Thus, the channeling of glutamate toward glutamine during hyperammonemia results in the net synthesis of 5-carbon units. This increase in 5-carbon units is accomplished in part by the ammonia-induced stimulation of the anaplerotic enzyme pyruvate carboxylase. Here, we suggest that glutamate may constitute a buffer or bulwark against changes in cerebral amine and ammonia nitrogen. Although the glutamate transporters are briefly discussed, the major emphasis of the present review is on the enzymology contributing to the maintenance of glutamate levels under normal and hyperammonemic conditions. Emphasis will also be placed on the central role of glutamate in the glutamine-glutamate and glutamine-GABA neurotransmitter cycles between neurons and astrocytes. Finally, we provide a brief and selective discussion of neuropathology associated with altered cerebral glutamate levels.
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17
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Dehghani M M, Lanz B, Duarte JMN, Kunz N, Gruetter R. Refined Analysis of Brain Energy Metabolism Using In Vivo Dynamic Enrichment of 13C Multiplets. ASN Neuro 2016; 8:8/2/1759091416632342. [PMID: 26969691 PMCID: PMC4790427 DOI: 10.1177/1759091416632342] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 12/30/2015] [Indexed: 11/18/2022] Open
Abstract
Carbon-13 nuclear magnetic resonance spectroscopy in combination with the infusion of 13C-labeled precursors is a unique approach to study in vivo brain energy metabolism. Incorporating the maximum information available from in vivo localized 13C spectra is of importance to get broader knowledge on cerebral metabolic pathways. Metabolic rates can be quantitatively determined from the rate of 13C incorporation into amino acid neurotransmitters such as glutamate and glutamine using suitable mathematical models. The time course of multiplets arising from 13C-13C coupling between adjacent carbon atoms was expected to provide additional information for metabolic modeling leading to potential improvements in the estimation of metabolic parameters. The aim of the present study was to extend two-compartment neuronal/glial modeling to include dynamics of 13C isotopomers available from fine structure multiplets in 13C spectra of glutamate and glutamine measured in vivo in rats brain at 14.1 T, termed bonded cumomer approach. Incorporating the labeling time courses of 13C multiplets of glutamate and glutamine resulted in elevated precision of the estimated fluxes in rat brain as well as reduced correlations between them.
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Affiliation(s)
- Masoumeh Dehghani M
- Laboratory for Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland
| | - Bernard Lanz
- Laboratory for Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland
| | - João M N Duarte
- Laboratory for Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland Department of Radiology, University of Lausanne, Switzerland
| | - Nicolas Kunz
- CIBM-AIT, Ecole Polytechnique Fédérale de Lausanne, Switzerland
| | - Rolf Gruetter
- Laboratory for Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland Department of Radiology, University of Lausanne, Switzerland Department of Radiology, University of Geneva, Switzerland
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18
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Cuellar-Baena S, Landeck N, Sonnay S, Buck K, Mlynarik V, In 't Zandt R, Kirik D. Assessment of brain metabolite correlates of adeno-associated virus-mediated over-expression of human alpha-synuclein in cortical neurons by in vivo (1) H-MR spectroscopy at 9.4 T. J Neurochem 2016; 137:806-19. [PMID: 26811128 DOI: 10.1111/jnc.13547] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 01/12/2016] [Accepted: 01/14/2016] [Indexed: 12/19/2022]
Abstract
In this study, we used proton-localized spectroscopy ((1) H-MRS) for the acquisition of the neurochemical profile longitudinally in a novel rat model of human wild-type alpha-synuclein (α-syn) over-expression. Our goal was to find out if the increased α-syn load in this model could be linked to changes in metabolites in the frontal cortex. Animals injected with AAV vectors encoding for human α-syn formed the experimental group, whereas green fluorescent protein expressing animals were used as the vector-treated control group and a third group of uninjected animals were used as naïve controls. Data were acquired at 2, 4, and 8 month time points. Nineteen metabolites were quantified in the MR spectra using LCModel software. On the basis of 92 spectra, we evaluated any potential gender effect and found that lactate (Lac) levels were lower in males compared to females, while the opposite was observed for ascorbate (Asc). Next, we assessed the effect of age and found increased levels of GABA, Tau, and GPC+PCho. Finally, we analyzed the effect of treatment and found that Lac levels (p = 0.005) were specifically lower in the α-syn group compared to the green fluorescent protein and control groups. In addition, Asc levels (p = 0.05) were increased in the vector-injected groups, whereas glucose levels remained unchanged. This study indicates that the metabolic switch between glucose-lactate could be detectable in vivo and might be modulated by Asc. No concomitant changes were found in markers of neuronal integrity (e.g., N-acetylaspartate) consistent with the fact that α-syn over-expression in cortical neurons did not result in neurodegeneration in this model. We acquired the neurochemical profile longitudinally in a rat model of human wild-type alpha-synuclein (α-syn) over-expression in cortical neurons. We found that Lactate levels were reduced in the α-syn group compared to the control groups and Ascorbate levels were increased in the vector-injected groups. No changes were found in markers of neuronal integrity consistent with the fact that α-syn over-expression did not result in frank neurodegeneration.
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Affiliation(s)
- Sandra Cuellar-Baena
- Brain Repair And Imaging in Neural Systems (B.R.A.I.N.S), Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Natalie Landeck
- Brain Repair And Imaging in Neural Systems (B.R.A.I.N.S), Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Sarah Sonnay
- Brain Repair And Imaging in Neural Systems (B.R.A.I.N.S), Department of Experimental Medical Science, Lund University, Lund, Sweden.,Laboratory of functional and metabolic imaging (LIFMET), École Polytechnique Fédérale de Lausanne EPFL, Lausanne, Switzerland
| | - Kerstin Buck
- Brain Repair And Imaging in Neural Systems (B.R.A.I.N.S), Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Vladimir Mlynarik
- Laboratory of functional and metabolic imaging (LIFMET), École Polytechnique Fédérale de Lausanne EPFL, Lausanne, Switzerland.,Department of Radiology and Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - René In 't Zandt
- Lund University BioImaging Center, Lund University, Lund, Sweden
| | - Deniz Kirik
- Brain Repair And Imaging in Neural Systems (B.R.A.I.N.S), Department of Experimental Medical Science, Lund University, Lund, Sweden.,Lund University BioImaging Center, Lund University, Lund, Sweden
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19
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Hollinshead KER, Williams DS, Tennant DA, Ludwig C. Probing Cancer Cell Metabolism Using NMR Spectroscopy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 899:89-111. [PMID: 27325263 DOI: 10.1007/978-3-319-26666-4_6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Altered cellular metabolism is now accepted to be at the core of many diseases including cancer. Over the past 20 years, NMR has become a core technology to study these metabolic perturbations in detail. This chapter reviews current NMR-based methods for steady-state metabolism and, in particular, the use of non-radioactive stable isotope-enriched tracers. Opportunities and challenges for each method, such as 1D (1)H NMR spectroscopy and (13)C carbon-based NMR spectroscopic methods, are discussed. Ultimately, the combination of NMR and mass spectra as orthogonal technologies are required to compensate for the drawbacks of each technique when used singly are discussed.
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Affiliation(s)
- Kate E R Hollinshead
- Institute of Metabolism and Systems Research, University of Birmingham, IBR, Edgbaston, Birmingham, B15 2TT, UK
| | - Debbie S Williams
- Institute of Metabolism and Systems Research, University of Birmingham, IBR, Edgbaston, Birmingham, B15 2TT, UK
| | - Daniel A Tennant
- Institute of Metabolism and Systems Research, University of Birmingham, IBR, Edgbaston, Birmingham, B15 2TT, UK
| | - Christian Ludwig
- Institute of Metabolism and Systems Research, University of Birmingham, IBR, Edgbaston, Birmingham, B15 2TT, UK.
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