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Sun C, Zhao Y, Zu Z. Evaluation of the molecular origin of amide proton transfer-weighted imaging. Magn Reson Med 2024; 91:716-734. [PMID: 37749854 PMCID: PMC10841347 DOI: 10.1002/mrm.29878] [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: 08/15/2023] [Accepted: 09/08/2023] [Indexed: 09/27/2023]
Abstract
PURPOSE To evaluate the assumption in amide proton transfer weighted (APTw) imaging that the APT dominates over the relayed nuclear Overhauser enhancement (rNOE) and other CEST effects such as those from amines/guanidines, thereby providing imaging of mobile proteins/peptides. METHODS We introduced two auxiliary asymmetric analysis metrics that can vary the relative contributions from amine/guanidinium CEST and other effects. By comparing these metrics with the conventional asymmetric analysis metric on healthy rat brains, we can approximately assess the contribution from amines/guanidines to APTw and determine whether the APT dominates over the rNOE effect. To further investigate the molecular origin of APTw, we used samples of dialyzed tissue homogenates to eliminate small metabolites and supernatants of homogenates to separate lipids from other components. RESULTS When the APTw signal is positive using high saturation amplitudes (e.g., 2-3 μT), the contributions from amines/guanidines are significant and cannot be ignored. The APTw signal from the dialyzed homogenates and the controls has negligible changes, indicating that it primarily originates from macromolecules rather than small metabolites. Additionally, the APTw signals with low saturation amplitudes (e.g., 1 μT) were negative in tissue homogenates but positive in their supernatants, suggesting that proteins contribute positively to APTw signals, whereas lipids contribute negatively to it. CONCLUSION The positive APTw signal using high saturation amplitudes could have significant contributions from soluble proteins through CEST, including amide/amine/guanidine proton transfer effects. In contrast, the negative APTw signal using low saturation amplitudes has significant contribution from lipids through rNOE.
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Affiliation(s)
- Casey Sun
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, US
- Department of Chemistry, University of Florida, Gainesville, US
| | - Yu Zhao
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, US
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, US
- Department of Radiology, West China Hospital of Sichuan University, Chengdu, China
| | - Zhongliang Zu
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, US
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, US
- Department of Biomedical Engineering, Vanderbilt University, Nashville, US
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2
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Zhao Y, Sun C, Zu Z. Assignment of molecular origins of NOE signal at -3.5 ppm in the brain. Magn Reson Med 2023; 90:673-685. [PMID: 36929814 PMCID: PMC10644915 DOI: 10.1002/mrm.29643] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 02/15/2023] [Accepted: 03/06/2023] [Indexed: 03/18/2023]
Abstract
PURPOSE Nuclear Overhauser enhancemen mediated saturation transfer effect, termed NOE (-3.5 ppm), is a major source of CEST MRI contrasts at 3.5 ppm in the brain. Previous phantom experiments have demonstrated that both proteins and lipids, two major components in tissues, have substantial contributions to NOE (-3.5 ppm) signals. Their relative contributions in tissues are informative for the interpretation of NOE (-3.5 ppm) contrasts that could provide potential imaging biomarkers for relevant diseases, which remain incompletely understood. METHODS Experiments on homogenates and supernatants of brain tissues collected from healthy rats, that could isolate proteins from lipids, were performed to evaluate the relative contribution of lipids to NOE (-3.5 ppm) signals. On the other hand, experiments on ghost membranes with varied pH, and reconstituted phospholipids with different chemical compositions were conducted to study the dependence of NOE (-3.5 ppm) on physiological conditions. Besides, CEST imaging on rat brains bearing 9 L tumors and healthy rat brains was performed to analyze the causes of the NOE (-3.5 ppm) contrast variations between tumors and normal tissues, and between gray matter and white matter. RESULTS Our experiments reveal that lipids have dominant contributions to the NOE (-3.5 ppm) signals. Further analysis suggests that decreased NOE (-3.5 ppm) signals in tumors and higher NOE (-3.5 ppm) signals in white matter than in gray matter are mainly explained by changes in membrane lipids, rather than proteins. CONCLUSION NOE (-3.5 ppm) could be exploited as a highly sensitive MRI contrast for imaging membrane lipids in the brain.
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Affiliation(s)
- Yu Zhao
- Vanderbilt University Institute of Imaging Science, Nashville, US
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, US
- Department of Radiology, West China Hospital of Sichuan University, Chengdu, China
| | - 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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3
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Zhao Y, Sun C, Zu Z. Assignment of molecular origins of NOE signal at -3.5 ppm in the brain. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.03.526979. [PMID: 36778370 PMCID: PMC9915742 DOI: 10.1101/2023.02.03.526979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Purpose Nuclear Overhauser Enhancement mediated saturation transfer effect, termed NOE(-3.5 ppm), is a major source of chemical exchange saturation transfer (CEST) MRI contrasts at 3.5 ppm in the brain. Previous phantom experiments have demonstrated that both proteins and lipids, two major components in tissues, have substantial contributions to NOE(-3.5 ppm) signals. Their relative contributions in tissues are informative for the interpretation of NOE(-3.5 ppm) contrasts that could provide potential imaging biomarkers for relevant diseases, which remain incompletely understood. Methods Experiments on homogenates and supernatants of brain tissues collected from healthy rats, that could isolate proteins from lipids, were performed to evaluate the relative contribution of lipids to NOE(-3.5 ppm) signals. On the other hand, experiments on ghost membranes with varied pH, and reconstituted phospholipids with different chemical compositions were conducted to study the dependence of NOE(-3.5 ppm) on physiological conditions. Besides, CEST imaging on rat brains bearing 9L tumors and healthy rat brains was performed to analyze the causes of the NOE(-3.5 ppm) contrast variations between tumors and normal tissues, and between gray matter and white matter. Results Our experiments reveal that lipids have dominant contributions to the NOE (-3.5 ppm) signals. Further analysis suggests that decreased NOE(-3.5 ppm) signals in tumors and higher NOE(-3.5 ppm) signals in white matter than in gray matter are mainly explained by changes in membrane lipids, rather than proteins. Conclusion NOE(-3.5 ppm) could be exploited as a highly sensitive MRI contrast for imaging membrane lipids in the brain.
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4
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Khalifa O, H. Mroue K, Mall R, Ullah E, S. Al-Akl N, Arredouani A. Investigation of the Effect of Exendin-4 on Oleic Acid-Induced Steatosis in HepG2 Cells Using Fourier Transform Infrared Spectroscopy. Biomedicines 2022; 10:biomedicines10102652. [PMID: 36289914 PMCID: PMC9599706 DOI: 10.3390/biomedicines10102652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 07/10/2022] [Accepted: 07/13/2022] [Indexed: 12/04/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is a common liver lesion that is untreatable with medications. Glucagon-like peptide-1 receptor (GLP-1R) agonists have recently emerged as a potential NAFLD pharmacotherapy. However, the molecular mechanisms underlying these drugs’ beneficial effects are not fully understood. Using Fourier transform infrared (FTIR) spectroscopy, we sought to investigate the biochemical changes in a steatosis cell model treated or not with the GLP-1R agonist Exendin-4 (Ex-4). HepG2 cells were made steatotic with 400 µM of oleic acid and then treated with 200 nM Ex-4 in order to reduce lipid accumulation. We quantified steatosis using the Oil Red O staining method. We investigated the biochemical alterations induced by steatosis and Ex-4 treatment using Fourier transform infrared (FTIR) spectroscopy and chemometric analyses. Analysis of the Oil Red O staining showed that Ex-4 significantly reduces steatosis. This reduction was confirmed by FTIR analysis, as the phospholipid band (C=O) at 1740 cm−1 in Ex-4 treated cells is significantly decreased compared to steatotic cells. The principal component analysis score plots for both the lipid and protein regions showed that the untreated and Ex-4-treated samples, while still separated, are clustered close to each other, far from the steatotic cells. The biochemical and structural changes induced by OA-induced lipotoxicity are at least partially reversed upon Ex-4 treatment. FTIR and chemometric analyses revealed that Ex-4 significantly reduces OA-induced lipid accumulation, and Ex-4 also restored the lipid and protein biochemical alterations caused by lipotoxicity-induced oxidative stress. In combination with chemometric analyses, FTIR spectroscopy may offer new approaches for investigating the mechanisms underpinning NAFLD.
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Affiliation(s)
- Olfa Khalifa
- Diabetes Research Center, Qatar Biomedical Research Institute, Hamad Bin Khalifa University, Qatar Foundation, Doha 34110, Qatar
| | - Kamal H. Mroue
- Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University (HBKU), Qatar Foundation, Doha 34110, Qatar
| | - Raghvendra Mall
- Qatar Computing Research Institute, Hamad Bin Khalifa University, Qatar Foundation, Doha 34110, Qatar
- Department of Immunology, St. Jude Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105-3678, USA
| | - Ehsan Ullah
- Qatar Computing Research Institute, Hamad Bin Khalifa University, Qatar Foundation, Doha 34110, Qatar
| | - Nayla S. Al-Akl
- Diabetes Research Center, Qatar Biomedical Research Institute, Hamad Bin Khalifa University, Qatar Foundation, Doha 34110, Qatar
| | - Abdelilah Arredouani
- Diabetes Research Center, Qatar Biomedical Research Institute, Hamad Bin Khalifa University, Qatar Foundation, Doha 34110, Qatar
- College of Health and Life Sciences, Hamad Bin Khalifa University, Qatar Foundation, Doha 34110, Qatar
- Correspondence:
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Tabtimmai L, Srisook P, Kuaprasert B, Thumanu K, Choowongkomon K. FTIR spectra signatures reveal different cellular effects of EGFR inhibitors on nonsmall cell lung cancer cells. JOURNAL OF BIOPHOTONICS 2020; 13:e201960012. [PMID: 31595681 DOI: 10.1002/jbio.201960012] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 08/25/2019] [Accepted: 10/02/2019] [Indexed: 06/10/2023]
Abstract
ATP-analogue inhibitors, Gefitinib (Iressa) and Erlotinib (Tarceva) had been approved for advanced and metastatic nonsmall cell lung cancer (NSCLC) cells against tyrosine kinase domain of epidermal growth factor receptor (EGFR). Many techniques have been developed to better understand the drug mechanism which is multistep, time-consuming and expensive. Herein, we performed Fourier-transform infrared (FTIR) microscopy for evaluating the biochemical change on NSCLC (A549) cells after treatment. At levels that produced equivalent effects, Gefitinib dramatically induced cell apoptosis via impaired mitochondrial transmembrane potential. Whereas, Erlotinib had a slight effect on A549. Principal component analysis was performed to distinguish the effect of EGFR inhibitors on A549. FTIR spectra regions were divided into three regions: lipids (3000-2800 cm-1 ), proteins (1700-1500 cm-1 ) and carbohydrates and nuclei acids (1200-1000 cm-1 ). Biochemical changes can be evaluated by these spectral regions. This work may be a novel concept for utilizing FTIR spectroscopy for high-throughput discriminative effects of a drug or compound and its derivatives on cells.
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Affiliation(s)
- Lueacha Tabtimmai
- Department of Biochemistry, Faculty of Science, Kasetsart University, Bangkok, Thailand
| | - Pimonwan Srisook
- Department of Biochemistry, Faculty of Science, Kasetsart University, Bangkok, Thailand
| | - Buabarn Kuaprasert
- Synchrotron Light Research Institute (Public Organization), Nakhon Ratchasrima, Thailand
| | - Kanjana Thumanu
- Synchrotron Light Research Institute (Public Organization), Nakhon Ratchasrima, Thailand
| | - Kiattawee Choowongkomon
- Department of Biochemistry, Faculty of Science, Kasetsart University, Bangkok, Thailand
- Center for Advanced Studies in Nanotechnology for Chemical, Food and Agricultural Industries, KU Institute for Advanced Studies, Kasetsart University, Bangkok, Thailand
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Duffy binding-like 1α adhesin from Plasmodium falciparum recognizes ABH histo-blood group saccharide in a type specific manner. Carbohydr Polym 2019; 207:266-275. [PMID: 30600009 DOI: 10.1016/j.carbpol.2018.11.082] [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: 06/21/2018] [Revised: 10/30/2018] [Accepted: 11/25/2018] [Indexed: 11/20/2022]
Abstract
The ability of erythrocytes, infected by Plasmodium falciparum, to adhere to endothelial cells (cytoadherence) and to capture uninfected erythrocyte (rosetting) is the leading cause of death by severe malaria. Evidences link the binding of the adhesin Duffy Binding Like1-α (DBL1α) domain to the ABH histo-blood antigens with formation of rosettes. Inspired by this very close relationship between the disease susceptibility and individual blood type, here we investigate the structural requirements involved in the interaction of DBL1α with A, B and H histo-blood determinants and their subtypes. Our results evidence the high preference of DBL1α to A epitopes, in comparison to B and H epitopes. DBL1α interacts with ABH epitopes in subtype specific manner, presenting a remarkable affinity for type 2 structures, Fucα1-2Galβ1-4GlcNAcβ1, particularly the A2 epitope. The contacts made by DBL1α binding pocket and the ABH histo-blood groups were mapped by theoretical methods and supported by NMR experiments.
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Prasad A, Chaichi A, Kelley DP, Francis J, Gartia MR. Current and future functional imaging techniques for post-traumatic stress disorder. RSC Adv 2019; 9:24568-24594. [PMID: 35527877 PMCID: PMC9069787 DOI: 10.1039/c9ra03562a] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Accepted: 08/02/2019] [Indexed: 11/21/2022] Open
Abstract
Posttraumatic stress disorder (PTSD) is a trauma and stressor related psychiatric disorder associated with structural, metabolic, and molecular alternations in several brain regions including diverse cortical areas, neuroendocrine regions, the striatum, dopaminergic, adrenergic and serotonergic pathways, and the limbic system. We are in critical need of novel therapeutics and biomarkers for PTSD and a deep understanding of cutting edge imaging and spectroscopy methods is necessary for the development of promising new approaches to better diagnose and treat the disorder. According to the Diagnostic and Statistical Manual of Mental Disorders (DSM-V) criterion, all forms of traumatic stress-induced disorder are considered acute stress disorder for the first month following the stressor. Only after symptoms do not remit for one month can the disorder be deemed PTSD. It would be particularly useful to differentiate between acute stress disorder and PTSD during the one month waiting period so that more intensive treatments can be applied early on to patients with a high likelihood of developing PTSD. This would potentially enhance treatment outcomes and/or prevent the development of PTSD. Comprehension of the qualities and limitations of currently applied methods as well as the novel emerging techniques provide invaluable knowledge for fast paced development. Conventional methods of studying PTSD have proven to be insufficient for diagnosis, measurement of treatment efficacy, and monitoring disease progression. As the field currently stands, there is no diagnostic biomarker available for any psychiatric disease, PTSD included. Currently, emerging and available technologies are not utilized to their full capacity and in appropriate experimental designs for the most fruitful possible studies in this area. Therefore, there is an apparent need for improved methods in PTSD research. This review demonstrates the current state of the literature in PTSD, including molecular, cellular, and behavioral indicators, possible biomarkers and clinical and pre-clinical imaging techniques relevant to PTSD, and through this, elucidate the void of current practical imaging and spectroscopy methods that provide true biomarkers for the disorder and the significance of devising new techniques for future investigations. We are unlikely to develop a single biomarker for any psychiatric disorder however. As psychiatric disorders are incomparably complex compared to other medical diagnoses, its most likely that transcriptomic, metabolomic and structural and connectomic imaging data will have to be analyzed in concert in order to produce a dependable non-behavioral marker of PTSD. This can explain the necessity of bridging conventional approaches to novel technologies in order to create a framework for further discoveries in the treatment of PTSD. Conventional methods of studying posttraumatic stress disorder (PTSD) have proven to be insufficient for diagnosis. We have reviewed clinical and preclinical imaging techniques as well as molecular, cellular, and behavioral indicators for PTSD.![]()
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Affiliation(s)
- Alisha Prasad
- Department of Mechanical and Industrial Engineering
- Louisiana State University
- Baton Rouge
- USA
| | - Ardalan Chaichi
- Department of Mechanical and Industrial Engineering
- Louisiana State University
- Baton Rouge
- USA
| | - D. Parker Kelley
- Comparative Biomedical Sciences
- School of Veterinary Medicine
- Louisiana State University
- Baton Rouge
- USA
| | - Joseph Francis
- Comparative Biomedical Sciences
- School of Veterinary Medicine
- Louisiana State University
- Baton Rouge
- USA
| | - Manas Ranjan Gartia
- Department of Mechanical and Industrial Engineering
- Louisiana State University
- Baton Rouge
- USA
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8
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Fimognari N, Hollings A, Lam V, Tidy RJ, Kewish CM, Albrecht MA, Takechi R, Mamo JCL, Hackett MJ. Biospectroscopic Imaging Provides Evidence of Hippocampal Zn Deficiency and Decreased Lipid Unsaturation in an Accelerated Aging Mouse Model. ACS Chem Neurosci 2018; 9:2774-2785. [PMID: 29901988 DOI: 10.1021/acschemneuro.8b00193] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Western society is facing a health epidemic due to the increasing incidence of dementia in aging populations, and there are still few effective diagnostic methods, minimal treatment options, and no cure. Aging is the greatest risk factor for memory loss that occurs during the natural aging process, as well as being the greatest risk factor for neurodegenerative disease such as Alzheimer's disease. Greater understanding of the biochemical pathways that drive a healthy aging brain toward dementia (pathological aging or Alzheimer's disease), is required to accelerate the development of improved diagnostics and therapies. Unfortunately, many animal models of dementia model chronic amyloid precursor protein overexpression, which although highly relevant to mechanisms of amyloidosis and familial Alzheimer's disease, does not model well dementia during the natural aging process. A promising animal model reported to model mechanisms of accelerated natural aging and memory impairments, is the senescence accelerated murine prone strain 8 (SAMP8), which has been adopted by many research group to study the biochemical transitions that occur during brain aging. A limitation to traditional methods of biochemical characterization is that many important biochemical and elemental markers (lipid saturation, lactate, transition metals) cannot be imaged at meso- or microspatial resolution. Therefore, in this investigation, we report the first multimodal biospectroscopic characterization of the SAMP8 model, and have identified important biochemical and elemental alterations, and colocalizations, between 4 month old SAMP8 mice and the relevant control (SAMR1) mice. Specifically, we demonstrate direct evidence of Zn deficiency within specific subregions of the hippocampal CA3 sector, which colocalize with decreased lipid unsaturation. Our findings also revealed colocalization of decreased lipid unsaturation and increased lactate in the corpus callosum white matter, adjacent to the hippocampus. Such findings may have important implication for future research aimed at elucidating specific biochemical pathways for therapeutic intervention.
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Affiliation(s)
- Nicholas Fimognari
- Curtin Health Innovation Research Institute, Curtin University, Bentley, WA 6102, Australia
- School of Biomedical Sciences, Curtin University, Bentley, WA 6102, Australia
| | - Ashley Hollings
- Curtin Health Innovation Research Institute, Curtin University, Bentley, WA 6102, Australia
- Curtin Institute for Functional Molecules and Interfaces, School of Molecular and Life Science, Curtin University, Bentley, WA 6845, Australia
| | - Virginie Lam
- Curtin Health Innovation Research Institute, Curtin University, Bentley, WA 6102, Australia
- School of Public Health, Curtin University, Bentley, WA 6102, Australia
| | - Rebecca J. Tidy
- Curtin Health Innovation Research Institute, Curtin University, Bentley, WA 6102, Australia
- Curtin Institute for Functional Molecules and Interfaces, School of Molecular and Life Science, Curtin University, Bentley, WA 6845, Australia
| | - Cameron M. Kewish
- Australian Nuclear Science and Technology Organisation, 800 Blackburn Road, Clayton, VIC 3168, Australia
| | - Matthew A. Albrecht
- Curtin Health Innovation Research Institute, Curtin University, Bentley, WA 6102, Australia
| | - Ryu Takechi
- Curtin Health Innovation Research Institute, Curtin University, Bentley, WA 6102, Australia
- School of Public Health, Curtin University, Bentley, WA 6102, Australia
| | - John C. L. Mamo
- Curtin Health Innovation Research Institute, Curtin University, Bentley, WA 6102, Australia
- School of Public Health, Curtin University, Bentley, WA 6102, Australia
| | - Mark J. Hackett
- Curtin Health Innovation Research Institute, Curtin University, Bentley, WA 6102, Australia
- Curtin Institute for Functional Molecules and Interfaces, School of Molecular and Life Science, Curtin University, Bentley, WA 6845, Australia
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Zhang XY, Xie J, Wang F, Lin EC, Xu J, Gochberg DF, Gore JC, Zu Z. Assignment of the molecular origins of CEST signals at 2 ppm in rat brain. Magn Reson Med 2017; 78:881-887. [PMID: 28653349 DOI: 10.1002/mrm.26802] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 05/26/2017] [Accepted: 05/27/2017] [Indexed: 01/13/2023]
Abstract
PURPOSE Chemical exchange saturation transfer effects at 2 ppm (CEST@2ppm) in brain have previously been interpreted as originating from creatine. However, protein guanidino amine protons may also contribute to CEST@2ppm. This study aims to investigate the molecular origins and specificity of CEST@2ppm in brain. METHODS Two experiments were performed: (i) samples containing egg white albumin and creatine were dialyzed using a semipermeable membrane to demonstrate that proteins and creatine can be separated by this method; and (ii) tissue homogenates of rat brain with and without dialysis to remove creatine were studied to measure the relative contributions of proteins and creatine to CEST@2ppm. RESULTS The experiments indicate that dialysis can successfully remove creatine from proteins. Measurements on tissue homogenates show that, with the removal of creatine via dialysis, CEST@2ppm decreases to approximately 34% of its value before dialysis, which indicates that proteins and creatine have comparable contribution to the CEST@2ppm in brain. However, considering the contribution from peptides and amino acids to CEST@2ppm, creatine may have much less contribution to CEST@2ppm. CONCLUSIONS The contribution of proteins, peptides, and amino acids to CEST@2ppm cannot be neglected. The CEST@2ppm measurements of creatine in rat brain should be interpreted with caution. Magn Reson Med 78:881-887, 2017. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Xiao-Yong Zhang
- Vanderbilt University Institute of Imaging Science, Nashville, Tennessee, USA.,Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Jingping Xie
- Vanderbilt University Institute of Imaging Science, Nashville, Tennessee, USA.,Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Feng Wang
- Vanderbilt University Institute of Imaging Science, Nashville, Tennessee, USA.,Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Eugene C Lin
- Vanderbilt University Institute of Imaging Science, Nashville, Tennessee, USA.,Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Junzhong Xu
- Vanderbilt University Institute of Imaging Science, 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, Nashville, Tennessee, USA.,Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA.,Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA
| | - John C Gore
- Vanderbilt University Institute of Imaging Science, 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, Nashville, Tennessee, USA.,Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA
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10
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Lee J, Wen B, Carter EA, Combes V, Grau GER, Lay PA. Infrared spectroscopic characterization of monocytic microvesicles (microparticles) released upon lipopolysaccharide stimulation. FASEB J 2017; 31:2817-2827. [PMID: 28314769 DOI: 10.1096/fj.201601272r] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Accepted: 02/26/2017] [Indexed: 12/28/2022]
Abstract
Microvesicles (MVs) are involved in cell-cell interactions, including disease pathogenesis. Nondestructive Fourier-transform infrared (FTIR) spectra from MVs were assessed as a technique to provide new biochemical insights into a LPS-induced monocyte model of septic shock. FTIR spectroscopy provided a quick method to investigate relative differences in biomolecular content of different MV populations that was complementary to traditional semiquantitative omics approaches, with which it is difficult to provide information on relative changes between classes (proteins, lipids, nucleic acids, carbohydrates) or protein conformations. Time-dependent changes were detected in biomolecular contents of MVs and in the monocytes from which they were released. Differences in phosphatidylcholine and phosphatidylserine contents were observed in MVs released under stimulation, and higher relative concentrations of RNA and α-helical structured proteins were present in stimulated MVs compared with MVs from resting cells. FTIR spectra of stimulated monocytes displayed changes that were consistent with those observed in the corresponding MVs they released. LPS-stimulated monocytes had reduced concentrations of nucleic acids, α-helical structured proteins, and phosphatidylcholine compared with resting monocytes but had an increase in total lipids. FTIR spectra of MV biomolecular content will be important in shedding new light on the mechanisms of MVs and the different roles they play in physiology and disease pathogenesis.-Lee, J., Wen, B., Carter, E. A., Combes, V., Grau, G. E. R., Lay, P. A. Infrared spectroscopic characterization of monocytic microvesicles (microparticles) released upon lipopolysaccharide stimulation.
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Affiliation(s)
- Joonsup Lee
- School of Chemistry and Vibrational Spectroscopy Core Facility, The University of Sydney, Sydney, New South Wales, Australia
| | - Beryl Wen
- Vascular Immunopathology Unit, Bosch Institute-School of Medical Sciences, and
| | - Elizabeth A Carter
- School of Chemistry and Vibrational Spectroscopy Core Facility, The University of Sydney, Sydney, New South Wales, Australia
| | - Valery Combes
- Vascular Immunopathology Unit, Bosch Institute-School of Medical Sciences, and.,Faculty of Science, School of Life Sciences, University of Technology Sydney, Sydney, New South Wales, Australia
| | - Georges E R Grau
- Vascular Immunopathology Unit, Bosch Institute-School of Medical Sciences, and.,Australian Institute of Nanoscale Science and Technology (AINST), The University of Sydney, Sydney, New South Wales, Australia
| | - Peter A Lay
- School of Chemistry and Vibrational Spectroscopy Core Facility, The University of Sydney, Sydney, New South Wales, Australia; .,Australian Institute of Nanoscale Science and Technology (AINST), The University of Sydney, Sydney, New South Wales, Australia
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11
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Caine S, Hackett MJ, Hou H, Kumar S, Maley J, Ivanishvili Z, Suen B, Szmigielski A, Jiang Z, Sylvain NJ, Nichol H, Kelly ME. A novel multi-modal platform to image molecular and elemental alterations in ischemic stroke. Neurobiol Dis 2016; 91:132-42. [DOI: 10.1016/j.nbd.2016.03.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 02/13/2016] [Accepted: 03/07/2016] [Indexed: 02/06/2023] Open
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12
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Pilling M, Gardner P. Fundamental developments in infrared spectroscopic imaging for biomedical applications. Chem Soc Rev 2016; 45:1935-57. [PMID: 26996636 DOI: 10.1039/c5cs00846h] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Infrared chemical imaging is a rapidly emerging field with new advances in instrumentation, data acquisition and data analysis. These developments have had significant impact in biomedical applications and numerous studies have now shown that this technology offers great promise for the improved diagnosis of the diseased state. Relying on purely biochemical signatures rather than contrast from exogenous dyes and stains, infrared chemical imaging has the potential to revolutionise histopathology for improved disease diagnosis. In this review we discuss the recent advances in infrared spectroscopic imaging specifically related to spectral histopathology (SHP) and consider the current state of the field. Finally we consider the practical application of SHP for disease diagnosis and consider potential barriers to clinical translation highlighting current directions and the future outlook.
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Affiliation(s)
- Michael Pilling
- Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK.
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13
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Kochan K, Maslak E, Chlopicki S, Baranska M. FT-IR imaging for quantitative determination of liver fat content in non-alcoholic fatty liver. Analyst 2016; 140:4997-5002. [PMID: 26051164 DOI: 10.1039/c5an00737b] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
In this work we apply FT-IR imaging of large areas of liver tissue cross-section samples (∼5 cm × 5 cm) for quantitative assessment of steatosis in murine model of Non-Alcoholic Fatty Liver (NAFLD). We quantified the area of liver tissue occupied by lipid droplets (LDs) by FT-IR imaging and Oil Red O (ORO) staining for comparison. Two alternative FT-IR based approaches are presented. The first, straightforward method, was based on average spectra from tissues and provided values of the fat content by using a PLS regression model and the reference method. The second one – the chemometric-based method – enabled us to determine the values of the fat content, independently of the reference method by means of k-means cluster (KMC) analysis. In summary, FT-IR images of large size liver sections may prove to be useful for quantifying liver steatosis without the need of tissue staining.
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Affiliation(s)
- K Kochan
- Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University, Krakow, Poland.
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14
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Hackett MJ, Smith SE, Caine S, Nichol H, George GN, Pickering IJ, Paterson PG. Novel bio-spectroscopic imaging reveals disturbed protein homeostasis and thiol redox with protein aggregation prior to hippocampal CA1 pyramidal neuron death induced by global brain ischemia in the rat. Free Radic Biol Med 2015; 89:806-18. [PMID: 26454085 PMCID: PMC5509437 DOI: 10.1016/j.freeradbiomed.2015.08.029] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 08/16/2015] [Accepted: 08/31/2015] [Indexed: 10/22/2022]
Abstract
Global brain ischemia resulting from cardiac arrest and cardiac surgery can lead to permanent brain damage and mental impairment. A clinical hallmark of global brain ischemia is delayed neurodegeneration, particularly within the CA1 subsector of the hippocampus. Unfortunately, the biochemical mechanisms have not been fully elucidated, hindering optimization of current therapies (i.e., therapeutic hypothermia) or development of new therapies. A major limitation to elucidating the mechanisms that contribute to neurodegeneration and understanding how these are influenced by potential therapies is the inability to relate biochemical markers to alterations in the morphology of individual neurons. Although immunocytochemistry allows imaging of numerous biochemical markers at the sub-cellular level, it is not a direct chemical imaging technique and requires successful "tagging" of the desired analyte. Consequently, important biochemical parameters, particularly those that manifest from oxidative damage to biological molecules, such as aggregated protein levels, have been notoriously difficult to image at the cellular or sub-cellular level. It has been hypothesized that reactive oxygen species (ROS) generated during ischemia and reperfusion facilitate protein aggregation, impairing neuronal protein homeostasis (i.e., decreasing protein synthesis) that in turn promotes neurodegeneration. Despite indirect evidence for this theory, direct measurements of morphology and ROS induced biochemical damage, such as increased protein aggregates and decreased protein synthesis, within the same neuron is lacking, due to the unavailability of a suitable imaging method. Our experimental approach has incorporated routine histology with novel wide-field synchrotron radiation Fourier transform infrared imaging (FTIRI) of the same neurons, ex vivo within brain tissue sections. The results demonstrate for the first time that increased protein aggregation and decreased levels of total protein occur in the same CA1 pyramidal neurons 1 day after global ischemia. Further, analysis of serial tissue sections using X-ray absorption spectroscopy at the sulfur K-edge has revealed that CA1 pyramidal neurons have increased disulfide levels, a direct indicator of oxidative stress, at this time point. These changes at 1 day after ischemia precede a massive increase in aggregated protein and disulfide levels concomitant with loss of neuron integrity 2 days after ischemia. Therefore, this study has provided direct support for a correlative mechanistic link in both spatial and temporal domains between oxidative stress, protein aggregation and altered protein homeostasis prior to irreparable neuron damage following global ischemia.
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Affiliation(s)
- Mark J Hackett
- Molecular and Environmental Sciences Group, Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Shari E Smith
- College of Pharmacy and Nutrition, University of Saskatchewan, 107 Wiggins Rd, Saskatoon, Saskatchewan, S7N 5E5, Canada
| | - Sally Caine
- Department of Anatomy and Cell Biology, University of Saskatchewan, 107 Wiggins Rd, Saskatoon, Saskatchewan, S7N 5E5, Canada
| | - Helen Nichol
- Department of Anatomy and Cell Biology, University of Saskatchewan, 107 Wiggins Rd, Saskatoon, Saskatchewan, S7N 5E5, Canada
| | - Graham N George
- Molecular and Environmental Sciences Group, Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada; Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, Saskatchewan S7N 5C9, Canada
| | - Ingrid J Pickering
- Molecular and Environmental Sciences Group, Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada; Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, Saskatchewan S7N 5C9, Canada
| | - Phyllis G Paterson
- College of Pharmacy and Nutrition, University of Saskatchewan, 107 Wiggins Rd, Saskatoon, Saskatchewan, S7N 5E5, Canada.
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15
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Hackett MJ, Aitken JB, El-Assaad F, McQuillan JA, Carter EA, Ball HJ, Tobin MJ, Paterson D, de Jonge MD, Siegele R, Cohen DD, Vogt S, Grau GE, Hunt NH, Lay PA. Mechanisms of murine cerebral malaria: Multimodal imaging of altered cerebral metabolism and protein oxidation at hemorrhage sites. SCIENCE ADVANCES 2015; 1:e1500911. [PMID: 26824064 PMCID: PMC4730848 DOI: 10.1126/sciadv.1500911] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 11/03/2015] [Indexed: 06/05/2023]
Abstract
Using a multimodal biospectroscopic approach, we settle several long-standing controversies over the molecular mechanisms that lead to brain damage in cerebral malaria, which is a major health concern in developing countries because of high levels of mortality and permanent brain damage. Our results provide the first conclusive evidence that important components of the pathology of cerebral malaria include peroxidative stress and protein oxidation within cerebellar gray matter, which are colocalized with elevated nonheme iron at the site of microhemorrhage. Such information could not be obtained previously from routine imaging methods, such as electron microscopy, fluorescence, and optical microscopy in combination with immunocytochemistry, or from bulk assays, where the level of spatial information is restricted to the minimum size of tissue that can be dissected. We describe the novel combination of chemical probe-free, multimodal imaging to quantify molecular markers of disturbed energy metabolism and peroxidative stress, which were used to provide new insights into understanding the pathogenesis of cerebral malaria. In addition to these mechanistic insights, the approach described acts as a template for the future use of multimodal biospectroscopy for understanding the molecular processes involved in a range of clinically important acute and chronic (neurodegenerative) brain diseases to improve treatment strategies.
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Affiliation(s)
- Mark J. Hackett
- School of Chemistry and Vibrational Spectroscopy Core Facility, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Jade B. Aitken
- School of Chemistry and Vibrational Spectroscopy Core Facility, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Fatima El-Assaad
- Vascular Immunology Unit, Bosch Institute and School of Medical Sciences, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - James A. McQuillan
- Molecular Immunopathology Unit, Bosch Institute and School of Medical Sciences, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Elizabeth A. Carter
- School of Chemistry and Vibrational Spectroscopy Core Facility, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Helen J. Ball
- Molecular Immunopathology Unit, Bosch Institute and School of Medical Sciences, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Mark J. Tobin
- Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168, Australia
| | - David Paterson
- Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168, Australia
| | - Martin D. de Jonge
- Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168, Australia
| | - Rainer Siegele
- Institute for Environmental Research, Australian Nuclear Science and Technology Organisation, Lucas Heights, New South Wales 2234, Australia
| | - David D. Cohen
- Institute for Environmental Research, Australian Nuclear Science and Technology Organisation, Lucas Heights, New South Wales 2234, Australia
| | - Stefan Vogt
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Georges E. Grau
- Vascular Immunology Unit, Bosch Institute and School of Medical Sciences, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Nicholas H. Hunt
- Molecular Immunopathology Unit, Bosch Institute and School of Medical Sciences, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Peter A. Lay
- School of Chemistry and Vibrational Spectroscopy Core Facility, The University of Sydney, Sydney, New South Wales 2006, Australia
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16
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Hackett MJ, Britz CJ, Paterson PG, Nichol H, Pickering IJ, George GN. In situ biospectroscopic investigation of rapid ischemic and postmortem induced biochemical alterations in the rat brain. ACS Chem Neurosci 2015; 6:226-38. [PMID: 25350866 PMCID: PMC4372066 DOI: 10.1021/cn500157j] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
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Rapid advances in
imaging technologies have pushed novel spectroscopic
modalities such as Fourier transform infrared spectroscopy (FTIR)
and X-ray absorption spectroscopy (XAS) at the sulfur K-edge to the
forefront of direct in situ investigation of brain biochemistry. However,
few studies have examined the extent to which sample preparation artifacts
confound results. Previous investigations using traditional analyses,
such as tissue dissection, homogenization, and biochemical assay,
conducted extensive research to identify biochemical alterations that
occur ex vivo during sample preparation. In particular, altered metabolism
and oxidative stress may be caused by animal death. These processes
were a concern for studies using biochemical assays, and protocols
were developed to minimize their occurrence. In this investigation,
a similar approach was taken to identify the biochemical alterations
that are detectable by two in situ spectroscopic methods (FTIR, XAS)
that occur as a consequence of ischemic conditions created during
humane animal killing. FTIR and XAS are well suited to study markers
of altered metabolism such as lactate and creatine (FTIR) and markers
of oxidative stress such as aggregated proteins (FTIR) and altered
thiol redox (XAS). The results are in accordance with previous investigations
using biochemical assays and demonstrate that the time between animal
death and tissue dissection results in ischemic conditions that alter
brain metabolism and initiate oxidative stress. Therefore, future
in situ biospectroscopic investigations utilizing FTIR and XAS must
take into consideration that brain tissue dissected from a healthy
animal does not truly reflect the in vivo condition, but rather reflects
a state of mild ischemia. If studies require the levels of metabolites
(lactate, creatine) and markers of oxidative stress (thiol redox)
to be preserved as close as possible to the in vivo condition, then
rapid freezing of brain tissue via decapitation into liquid nitrogen,
followed by chiseling the brain out at dry ice temperatures is required.
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Affiliation(s)
- Mark J. Hackett
- Molecular
and Environmental Sciences Group, Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Carter J. Britz
- Department
of Anatomy and Cell Biology, University of Saskatchewan, 107
Wiggins Rd, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Phyllis G. Paterson
- College
of Pharmacy and Nutrition, University of Saskatchewan, D Wing Health Sciences, 107 Wiggins Road, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Helen Nichol
- Department
of Anatomy and Cell Biology, University of Saskatchewan, 107
Wiggins Rd, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Ingrid J. Pickering
- Molecular
and Environmental Sciences Group, Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Graham N. George
- Molecular
and Environmental Sciences Group, Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada
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17
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Chwiej J, Skoczen A, Janeczko K, Kutorasinska J, Matusiak K, Figiel H, Dumas P, Sandt C, Setkowicz Z. The biochemical changes in hippocampal formation occurring in normal and seizure experiencing rats as a result of a ketogenic diet. Analyst 2015; 140:2190-204. [DOI: 10.1039/c4an01857e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this study, ketogenic diet-induced biochemical changes occurring in normal and epileptic hippocampal formations were compared.
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Affiliation(s)
- Joanna Chwiej
- AGH-University of Science and Technology
- Faculty of Physics and Applied Computer Science
- Krakow
- Poland
| | - Agnieszka Skoczen
- AGH-University of Science and Technology
- Faculty of Physics and Applied Computer Science
- Krakow
- Poland
| | | | - Justyna Kutorasinska
- AGH-University of Science and Technology
- Faculty of Physics and Applied Computer Science
- Krakow
- Poland
| | - Katarzyna Matusiak
- AGH-University of Science and Technology
- Faculty of Physics and Applied Computer Science
- Krakow
- Poland
| | - Henryk Figiel
- AGH-University of Science and Technology
- Faculty of Physics and Applied Computer Science
- Krakow
- Poland
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18
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Alaverdashvili M, Hackett MJ, Pickering IJ, Paterson PG. Laminar-specific distribution of zinc: evidence for presence of layer IV in forelimb motor cortex in the rat. Neuroimage 2014; 103:502-510. [PMID: 25192655 DOI: 10.1016/j.neuroimage.2014.08.046] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 06/29/2014] [Accepted: 08/24/2014] [Indexed: 10/24/2022] Open
Abstract
The rat is the most widely studied pre-clinical model system of various neurological and neurodegenerative disorders affecting hand function. Although brain injury to the forelimb region of the motor cortex in rats mostly induces behavioral abnormalities in motor control of hand movements, behavioral deficits in the sensory-motor domain are also observed. This questions the prevailing view that cortical layer IV, a recipient of sensory information from the thalamus, is absent in rat motor cortex. Because zinc-containing neurons are generally not found in pathways that run from the thalamus, an absence of zinc (Zn) in a cortical layer would be suggestive of sensory input from the thalamus. To test this hypothesis, we used synchrotron micro X-ray fluorescence imaging to measure Zn distribution across cortical layers. Zn maps revealed a heterogeneous layered Zn distribution in primary and secondary motor cortices of the forelimb region in the adult rat. Two wider bands with elevated Zn content were separated by a narrow band having reduced Zn content, and this was evident in two rat strains. The Zn distribution pattern was comparable to that in sensorimotor cortex, which is known to contain a well demarcated layer IV. Juxtaposition of Zn maps and the images of brain stained for Nissl bodies revealed a "Zn valley" in primary motor cortex, apparently starting at the ventral border of pyramidal layer III and ending at the close vicinity of layer V. This finding indicates the presence of a conspicuous cortical layer between layers III and V, i.e. layer IV, the presence of which previously has been disputed. The results have implications for the use of rat models to investigate human brain function and neuropathology, such as after stroke. The presence of layer IV in the forelimb region of the motor cortex suggests that therapeutic interventions used in rat models of motor cortex injury should target functional abnormalities in both motor and sensory domains. The finding is also critical for future investigation of the biochemical mechanisms through which therapeutic interventions can enhance neural plasticity, particularly through Zn dependent pathways.
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Affiliation(s)
- Mariam Alaverdashvili
- Neuroscience Research Group, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada; College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada.
| | - Mark J Hackett
- Neuroscience Research Group, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada; Department of Geological Sciences, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
| | - Ingrid J Pickering
- Department of Geological Sciences, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
| | - Phyllis G Paterson
- Neuroscience Research Group, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada; College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
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19
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WANG Q, JIANG XT, XIN YZ, CUI JX, ZHANG PD. Characterization of In vitro Mineralization of Porous Poly (L-Lactic Acid)/Bioactive Glass Composites by Attenuated Total Reflectance-Fourier Transform Infrared Mapping. CHINESE JOURNAL OF ANALYTICAL CHEMISTRY 2014. [DOI: 10.1016/s1872-2040(13)60713-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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20
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Hackett MJ, Borondics F, Brown D, Hirschmugl C, Smith SE, Paterson PG, Nichol H, Pickering IJ, George GN. Subcellular biochemical investigation of purkinje neurons using synchrotron radiation fourier transform infrared spectroscopic imaging with a focal plane array detector. ACS Chem Neurosci 2013; 4:1071-80. [PMID: 23638613 DOI: 10.1021/cn4000346] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Coupling Fourier transform infrared spectroscopy with focal plane array detectors at synchrotron radiation sources (SR-FTIR-FPA) has provided a rapid method to simultaneously image numerous biochemical markers in situ at diffraction limited resolution. Since cells and nuclei are well resolved at this spatial resolution, a direct comparison can be made between FTIR functional group images and the histology of the same section. To allow histological analysis of the same section analyzed with infrared imaging, unfixed air-dried tissue sections are typically fixed (after infrared spectroscopic analysis is completed) via immersion fixation. This post fixation process is essential to allow histological staining of the tissue section. Although immersion fixation is a common practice in this filed, the initial rehydration of the dehydrated unfixed tissue can result in distortion of subcellular morphology and confound correlation between infrared images and histology. In this study, vapor fixation, a common choice in other research fields where postfixation of unfixed tissue sections is required, was employed in place of immersion fixation post spectroscopic analysis. This method provided more accurate histology with reduced distortions as the dehydrated tissue section is fixed in vapor rather than during rehydration in an aqueous fixation medium. With this approach, accurate correlation between infrared images and histology of the same section revealed that Purkinje neurons in the cerebellum are rich in cytosolic proteins and not depleted as once thought. In addition, we provide the first direct evidence of intracellular lactate within Purkinje neurons. This highlights the significant potential for future applications of SR-FTIR-FPA imaging to investigate cellular lactate under conditions of altered metabolic demand such as increased brain activity and hypoxia or ischemia.
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Affiliation(s)
- Mark J. Hackett
- Molecular and Environmental Sciences Group, Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon,
Saskatchewan S7N5E2, Canada
| | | | - Devin Brown
- Department of Anatomy and Cell Biology, University of Saskatchewan, 107 Wiggins Rd, Saskatoon,
Saskatchewan S7N5E5, Canada
| | - Carol Hirschmugl
- Department of Physics, University of Wisconsin—Milwaukee, Milwaukee,
Wisconsin 53211, United States
| | - Shari E. Smith
- College of Pharmacy and Nutrition, University of Saskatchewan, 110 Science Place, Saskatoon, Saskatchewn S7N5C9, Canada
| | - Phyllis G. Paterson
- College of Pharmacy and Nutrition, University of Saskatchewan, 110 Science Place, Saskatoon, Saskatchewn S7N5C9, Canada
| | - Helen Nichol
- Department of Anatomy and Cell Biology, University of Saskatchewan, 107 Wiggins Rd, Saskatoon,
Saskatchewan S7N5E5, Canada
| | - Ingrid J. Pickering
- Molecular and Environmental Sciences Group, Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon,
Saskatchewan S7N5E2, Canada
| | - Graham N. George
- Molecular and Environmental Sciences Group, Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon,
Saskatchewan S7N5E2, Canada
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