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Pushie MJ, Kelly ME, Hackett MJ. Direct label-free imaging of brain tissue using synchrotron light: a review of new spectroscopic tools for the modern neuroscientist. Analyst 2019; 143:3761-3774. [PMID: 29961790 DOI: 10.1039/c7an01904a] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The incidence of brain disease and brain disorders is increasing on a global scale. Unfortunately, development of new therapeutic strategies has not increased at the same rate, and brain diseases and brain disorders now inflict substantial health and economic impacts. A greater understanding of the fundamental neurochemistry that underlies healthy brain function, and the chemical pathways that manifest in brain damage or malfunction, are required to enable and accelerate therapeutic development. A previous limitation to the study of brain function and malfunction has been the limited number of techniques that provide both a wealth of biochemical information, and spatially resolved information (i.e., there was a previous lack of techniques that provided direct biochemical or elemental imaging at the cellular level). In recent times, a suite of direct spectroscopic imaging techniques, such as Fourier transform infrared spectroscopy (FTIR), X-ray fluorescence microscopy (XFM), and X-ray absorption spectroscopy (XAS) have been adapted, optimized and integrated into the field of neuroscience, to fill the above mentioned capability-gap. Advancements at synchrotron light sources, such as improved light intensity/flux, increased detector sensitivities and new capabilities of imaging/optics, has pushed the above suite of techniques beyond "proof-of-concept" studies, to routine application to study complex research problems in the field of neuroscience (and other scientific disciplines). This review examines several of the major advancements that have occurred over the last several years, with respect to FTIR, XFM and XAS capabilities at synchrotron facilities, and how the increases in technical capabilities have being integrated and used in the field of neuroscience.
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Affiliation(s)
- M J Pushie
- Department of Surgery, Division of Neurosurgery, College of Medicine, University of Saskatchewan, 107 Wiggins Road, Saskatoon, Saskatchewan S7N 5E5, Canada
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Koudouna E, Mikula E, Brown DJ, Young RD, Quantock AJ, Jester JV. Cell regulation of collagen fibril macrostructure during corneal morphogenesis. Acta Biomater 2018; 79:96-112. [PMID: 30170195 DOI: 10.1016/j.actbio.2018.08.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 08/06/2018] [Accepted: 08/17/2018] [Indexed: 11/26/2022]
Abstract
While tissue form and function is highly dependent upon tissue-specific collagen composition and organization, little is known of the mechanisms controlling the bundling of collagen fibrils into fibers and larger structural designs that lead to the formation of bones, tendons and other tissues. Using the cornea as a model system, our previous 3 dimensional mapping of collagen fiber organization has demonstrated that macrostructural organization of collagen fibers involving interweaving, branching and anastomosing plays a critical role in controlling mechanical stiffness, corneal shape and refractive power. In this work, the cellular and mechanical mechanisms regulating critical events in the assembly of collagen macrostructure are analysed in the developing chicken cornea. We elucidated the temporal events leading to adult corneal structure and determined the effects of intraocular pressure (IOP) on the organization of the collagen macrostructure. Our findings indicate that the complex adult collagen organization begins to appear on embryonic day 10 (E10) after deposition of the primary stroma and full invasion of keratocytes. Importantly, organizational changes in keratocytes appearing at E9 preceded and predicted later changes in collagen organization. Corneal collagen organization remained unaffected when the development of IOP was blocked at E4. These findings support a primary role for keratocytes in controlling stromal organization, mechanical stiffness and corneal shape that are not regulated by the IOP. Our findings also suggest that the avian cornea represents an excellent experimental model for elucidating key regulatory steps and mechanisms controlling the collagen fiber organization that is critical to determining tissue form and function. STATEMENT OF SIGNIFICANCE This work by using an ex ovo model system, begins to investigate the potential mechanisms controlling collagen fibril macrostructure. In particular, this work highlights a convergent role for the corneal keratocytes in organizing the complex collagen macrostructure, necessary to support high visual acuity. Our data supports that the intraocular pressure does not influence collagen fibril macrostructure and suggest that the avian cornea represents an excellent experimental model for elucidating key regulatory steps and mechanisms controlling the collagen fiber organization that is critical to determining tissue form and function. Clearly understanding the cellular and molecular mechanisms that underlie collagen fibril macrostructure will be highly beneficial for future tissue engineering and regenerative medicine applications.
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Porcaro F, Roudeau S, Carmona A, Ortega R. Advances in element speciation analysis of biomedical samples using synchrotron-based techniques. Trends Analyt Chem 2018. [DOI: 10.1016/j.trac.2017.09.016] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Kozachuk M, Martin R, Sham T, Robinson M, Nelson A. The application of XANES for the examination of silver, gold, mercury, and sulfur on the daguerreotype surface. CAN J CHEM 2017. [DOI: 10.1139/cjc-2017-0062] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
X-ray absorption near edge structure (XANES) spectroscopy was used to study a freshly prepared reference daguerreotype surface as the first step in devising improved methods for the conservation of these important historic artifacts. The results are consistent with the formation of alloy image particles. Interdiffusion of gold and silver has led to the development of a silver–gold alloy; the composition varies with depth. The amount of gold appeared to be elevated in the highlighted regions of the image, whereas shadow regions have lower levels of gold on the surface. The apparent increase in gold within the highlighted region may be due to the larger surface area presented by an array of small image particles. The mercury used to develop the daguerreian image showed no evidence of oxidation while a mercury–silver alloy was detected. Sulfur-based contaminants are also detected. The implications of these findings are discussed.
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Affiliation(s)
- M.S. Kozachuk
- Department of Chemistry, University of Western Ontario, 1151 Richmond Street, London, ON N6A 5B7, Canada
| | - R.R. Martin
- Department of Chemistry, University of Western Ontario, 1151 Richmond Street, London, ON N6A 5B7, Canada
| | - T.K. Sham
- Department of Chemistry, University of Western Ontario, 1151 Richmond Street, London, ON N6A 5B7, Canada
| | - M. Robinson
- Century Darkroom, 245 Carlaw Avenue, Studio 502, Toronto, ON M4M 2S1, Canada
| | - A.J. Nelson
- Department of Anthropology, University of Western Ontario, 1151 Richmond Street, London, ON N6A 5B7, Canada
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Xiao Q, Maclennan A, Hu Y, Hackett M, Leinweber P, Sham TK. Medium-energy microprobe station at the SXRMB of the CLS. JOURNAL OF SYNCHROTRON RADIATION 2017; 24:333-337. [PMID: 28009575 DOI: 10.1107/s1600577516017604] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 11/04/2016] [Indexed: 06/06/2023]
Abstract
Micro-XAFS and chemical imaging techniques have been widely applied for studies of heterogeneously distributed systems, mostly in hard X-ray (>5 keV) or in soft X-ray (<1.5 keV) energies. The microprobe endstation of the SXRMB (soft X-ray microcharacterization beamline) at the Canadian Light Source is optimized at the medium energy (1.7-5 keV), and it has been recently commissioned and is available for general users. The technical design and the performance (energy range, beam size and flux) of the SXRMB microprobe are presented. Examples in chemical imaging and micro-XAFS in the medium energy for important elements such as P, S and Ca for soil and biological samples are highlighted.
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Affiliation(s)
- Qunfeng Xiao
- Canadian Light Source, 44 Innovation Boulevard, Saskatoon, SK, Canada S7N 2V3
| | - Aimee Maclennan
- Canadian Light Source, 44 Innovation Boulevard, Saskatoon, SK, Canada S7N 2V3
| | - Yongfeng Hu
- Canadian Light Source, 44 Innovation Boulevard, Saskatoon, SK, Canada S7N 2V3
| | - Mark Hackett
- Department of Geological Sciences, University of Saskatchewan, Saskatoon, SK, Canada S7N 5E2
| | - Peter Leinweber
- Soil Science, Faculty for Agricultural and Environmental Sciences, University of Rostock, Justus-von-Liebig Weg 6, 18051 Rostock, Germany
| | - Tsun Kong Sham
- Department of Chemistry, The University of Western Ontario, 1151 Richmond Street, London, ONT, Canada N6A 5B7
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Hackett MJ, Paterson PG, Pickering IJ, George GN. Imaging Taurine in the Central Nervous System Using Chemically Specific X-ray Fluorescence Imaging at the Sulfur K-Edge. Anal Chem 2016; 88:10916-10924. [PMID: 27700065 DOI: 10.1021/acs.analchem.6b02298] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A method to image taurine distributions within the central nervous system and other organs has long been sought. Since taurine is small and mobile, it cannot be chemically "tagged" and imaged using conventional immuno-histochemistry methods. Combining numerous indirect measurements, taurine is known to play critical roles in brain function during health and disease and is proposed to act as a neuro-osmolyte, neuro-modulator, and possibly a neuro-transmitter. Elucidation of taurine's neurochemical roles and importance would be substantially enhanced by a direct method to visualize alterations, due to physiological and pathological events in the brain, in the local concentration of taurine at or near cellular spatial resolution in vivo or in situ in tissue sections. We thus have developed chemically specific X-ray fluorescence imaging (XFI) at the sulfur K-edge to image the sulfonate group in taurine in situ in ex vivo tissue sections. To our knowledge, this represents the first undistorted imaging of taurine distribution in brain at 20 μm resolution. We report quantitative technique validation by imaging taurine in the cerebellum and hippocampus regions of the rat brain. Further, we apply the technique to image taurine loss from the vulnerable CA1 (cornus ammonis 1) sector of the rat hippocampus following global brain ischemia. The location-specific loss of taurine from CA1 but not CA3 neurons following ischemia reveals osmotic stress may be a key factor in delayed neurodegeneration after a cerebral ischemic insult and highlights the significant potential of chemically specific XFI to study the role of taurine in brain disease.
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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.,Department of Chemistry, Curtin University , GPO Box U1987, Perth, Western Australia 6845, Australia
| | - Phyllis G Paterson
- College of Pharmacy and Nutrition, University of Saskatchewan , 107 Wiggins Road, 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.,Department of Chemistry, University of Saskatchewan , 110 Science Place, Saskatoon, Saskatchewan S7N 5C9, Canada
| | - Graham N George
- Molecular and Environmental Sciences Group, Department of 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
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Ben Lakhdar A, Daudon M, Mathieu MC, Kellum A, Balleyguier C, Bazin D. Underlining the complexity of the structural and chemical characteristics of ectopic calcifications in breast tissues through FE-SEM and μFTIR spectroscopy. CR CHIM 2016. [DOI: 10.1016/j.crci.2015.03.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Hackett MJ, George GN, Pickering IJ, Eames BF. Chemical Biology in the Embryo: In Situ Imaging of Sulfur Biochemistry in Normal and Proteoglycan-Deficient Cartilage Matrix. Biochemistry 2016; 55:2441-51. [PMID: 26985789 DOI: 10.1021/acs.biochem.5b01136] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Proteoglycans (PGs) are heavily glycosylated proteins that play major structural and biological roles in many tissues. Proteoglycans are abundant in cartilage extracellular matrix; their loss is a main feature of the joint disease osteoarthritis. Proteoglycan function is regulated by sulfation-sulfate ester formation with specific sugar residues. Visualization of sulfation within cartilage matrix would yield vital insights into its biological roles. We present synchrotron-based X-ray fluorescence imaging of developing zebrafish cartilage, providing the first in situ maps of sulfate ester distribution. Levels of both sulfur and sulfate esters decrease as cartilage develops through late phase differentiation (maturation or hypertrophy), suggesting a functional link between cartilage matrix sulfur content and chondrocyte differentiation. Genetic experiments confirm that sulfate ester levels were due to cartilage proteoglycans and support the hypothesis that sulfate ester levels regulate chondrocyte differentiation. Surprisingly, in the PG synthesis mutant, the total level of sulfur was not significantly reduced, suggesting sulfur is distributed in an alternative chemical form during lowered cartilage proteoglycan production. Fourier transform infrared imaging indicated increased levels of protein in the mutant fish, suggesting that this alternative sulfur form might be ascribed to an increased level of protein synthesis in the mutant fish, as part of a compensatory mechanism.
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Affiliation(s)
- Mark J Hackett
- Molecular and Environmental Sciences Group, Department of Geological Sciences, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Graham N George
- Molecular and Environmental Sciences Group, Department of Geological Sciences, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5E2, Canada.,Department of Chemistry, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5C9, Canada.,Toxicology Centre, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5B3, Canada
| | - Ingrid J Pickering
- Molecular and Environmental Sciences Group, Department of Geological Sciences, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5E2, Canada.,Department of Chemistry, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5C9, Canada.,Toxicology Centre, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5B3, Canada
| | - B Frank Eames
- Department of Anatomy and Cell Biology, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5E5, Canada
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Czapla-Masztafiak J, Okoń K, Gałka M, Huthwelker T, Kwiatek WM. Investigating the Distribution of Chemical Forms of Sulfur in Prostate Cancer Tissue Using X-ray Absorption Spectroscopy. APPLIED SPECTROSCOPY 2016; 70:264-271. [PMID: 26903562 DOI: 10.1177/0003702815620128] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 06/22/2015] [Indexed: 06/05/2023]
Abstract
The use of synchrotron radiation may shed more light on the study of prostate cancer, one of the leading diseases among men. In the presented study the microbeam setup at the PSI Swiss Light Source combined with fluorescence detected X-ray absorption spectroscopy (XAS) was applied to determine two-dimensional (2D) imaging of distributions of various chemical sulfur forms in prostate cancer tissue sections, since sulfur is considered important and essential in cancer progression. The research focused on prostate tissues obtained during routine prostatectomies on patients suffering from prostate cancer.Our previous studies using μ-XAS point measurements on prostate cancer cell lines showed the differences in fractions of various forms of sulfur between cancerous and non-cancerous cells. Therefore, in this experiment the chosen areas of prostate cancer tissues were scanned to get the full picture of the chemical composition of tissue, which is highly heterogeneous. The incident X-ray beams of energies tuned to spectroscopic features of the near-edge region of sulfur K-edge absorption spectra were used to provide contrast between chemical species presented in the tissue. Next, the relative content of the three main sulfur forms, found in biological systems, was calculated and the results are presented in a form of 2D color maps. These maps are correlated with the microscopic histological image of the scanned area.The main findings show that sulfur occurs in prostate tissue mainly in reduced form. The oxidized form of sulfur is present mostly in prostatic stroma, while sulfur in intermediate oxidation state is present in trace amount.
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Affiliation(s)
| | - Krzysztof Okoń
- Chair of Pathomorphology, Jagiellonian University Medical College, Kraków, Poland
| | - Marek Gałka
- Gabriel Narutowicz City Specialist Hospital, Kraków, Poland
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Urgast DS, Beattie JH, Feldmann J. Imaging of trace elements in tissues: with a focus on laser ablation inductively coupled plasma mass spectrometry. Curr Opin Clin Nutr Metab Care 2014; 17:431-9. [PMID: 25023186 DOI: 10.1097/mco.0000000000000087] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
PURPOSE OF REVIEW Elemental imaging techniques are capable of showing the spatial distribution of elements in a sample. Their application in biomedical sciences is promising, but they are not yet widely employed. The review gives a short overview about techniques available and then focuses on the advantages of using laser ablation inductively coupled plasma mass spectrometry for elemental bioimaging. Current examples for the use of elemental imaging with medical context are given to illustrate the potential of this type of analysis for clinical applications. RECENT FINDINGS Recently, synchrotron-based techniques and laser ablation inductively coupled plasma mass spectrometry have been successfully applied to analyse the spatial distribution of elements in biological samples of medical relevance. SUMMARY Elemental bioimaging methods have a great potential for medical applications. They are complementary to molecular imaging and histological staining and are especially attractive when used in combination with stable isotope tracer experiments.
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Affiliation(s)
- Dagmar S Urgast
- aTrace Element Speciation Laboratory, Department of Chemistry, College of Physical Science bMicronutrients Group, Rowett Institute of Nutrition and Health, College of Life Sciences and Medicine, University of Aberdeen, Aberdeen, Scotland, United Kingdom
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