1
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Ashford F, Kuo CW, Dunning E, Brown E, Calagan S, Jayasinghe I, Henderson C, Fuller W, Wypijewski K. Cysteine post-translational modifications regulate protein interactions of caveolin-3. FASEB J 2024; 38:e23535. [PMID: 38466300 DOI: 10.1096/fj.202201497rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 02/12/2024] [Accepted: 02/20/2024] [Indexed: 03/12/2024]
Abstract
Caveolae are small flask-shaped invaginations of the surface membrane which are proposed to recruit and co-localize signaling molecules. The distinctive caveolar shape is achieved by the oligomeric structural protein caveolin, of which three isoforms exist. Aside from the finding that caveolin-3 is specifically expressed in muscle, functional differences between the caveolin isoforms have not been rigorously investigated. Caveolin-3 is relatively cysteine-rich compared to caveolins 1 and 2, so we investigated its cysteine post-translational modifications. We find that caveolin-3 is palmitoylated at 6 cysteines and becomes glutathiolated following redox stress. We map the caveolin-3 palmitoylation sites to a cluster of cysteines in its C terminal membrane domain, and the glutathiolation site to an N terminal cysteine close to the region of caveolin-3 proposed to engage in protein interactions. Glutathiolation abolishes caveolin-3 interaction with heterotrimeric G protein alpha subunits. Our results indicate that a caveolin-3 oligomer contains up to 66 palmitates, compared to up to 33 for caveolin-1. The additional palmitoylation sites in caveolin-3 therefore provide a mechanistic basis by which caveolae in smooth and striated muscle can possess unique phospholipid and protein cargoes. These unique adaptations of the muscle-specific caveolin isoform have important implications for caveolar assembly and signaling.
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Affiliation(s)
- Fiona Ashford
- School of Medicine, University of Dundee, Dundee, UK
| | - Chien-Wen Kuo
- School of Cardiovascular & Metabolic Health, University of Glasgow, Glasgow, UK
| | - Emma Dunning
- School of Cardiovascular & Metabolic Health, University of Glasgow, Glasgow, UK
| | - Elaine Brown
- School of Cardiovascular & Metabolic Health, University of Glasgow, Glasgow, UK
| | - Sarah Calagan
- School of Biomedical Sciences, University of Leeds, Leeds, UK
| | - Izzy Jayasinghe
- School of Biomedical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | | | - William Fuller
- School of Cardiovascular & Metabolic Health, University of Glasgow, Glasgow, UK
| | - Krzysztof Wypijewski
- School of Cardiovascular & Metabolic Health, University of Glasgow, Glasgow, UK
- School of Life Sciences, University of Dundee, Dundee, UK
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2
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Aghi K, Anderson BM, Castellano BM, Cunningham A, Delano M, Dickinson ES, von Diezmann L, Forslund-Startceva SK, Grijseels DM, Groh SS, Guthman EM, Jayasinghe I, Johnston J, Long S, McLaughlin JF, McLaughlin M, Miyagi M, Rajaraman B, Sancheznieto F, Scheim AI, Sun SED, Titmuss FD, Walsh RJ, Weinberg ZY. Rigorous science demands support of transgender scientists. Cell 2024; 187:1327-1334. [PMID: 38490174 DOI: 10.1016/j.cell.2024.02.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 02/09/2024] [Accepted: 02/20/2024] [Indexed: 03/17/2024]
Abstract
To build a just, equitable, and diverse academy, scientists and institutions must address systemic barriers that sex and gender minorities face. This Commentary summarizes (1) critical context informing the contemporary oppression of transgender people, (2) how this shapes extant research on sex and gender, and (3) actions to build an inclusive and rigorous academy for all.
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Affiliation(s)
- Krisha Aghi
- Department of Integrative Biology and Physiology, UCLA, Los Angeles, CA, USA
| | | | | | | | - Maggie Delano
- Department of Engineering, Swarthmore College, Swarthmore, PA, USA
| | | | - Lexy von Diezmann
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN, USA.
| | - Sofia Kirke Forslund-Startceva
- Experimental and Clinical Research Centre, a joint venture of Charité University Hospital and the Max Delbrück Centre, Berlin, Germany
| | - Dori M Grijseels
- Social Systems and Circuits Group, Max Planck Institute for Brain Research, Frankfurt am Main, Germany
| | - Sebastian S Groh
- Quality Enhancement Directorate, Cardiff Metropolitan University, Cardiff, UK
| | - Eartha Mae Guthman
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA; Center for Applied Transgender Studies, Chicago, IL, USA
| | - Izzy Jayasinghe
- School of Biosciences, The University of Sheffield, Sheffield, UK; Department of Molecular Medicine, University of New South Wales, Sydney, Australia
| | - Juliet Johnston
- Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Sam Long
- Denver Public Schools, Denver, CO, USA
| | - Jess F McLaughlin
- Department of Environmental Conservation, University of Massachusetts Amherst, Amherst, MA, USA
| | - Maeve McLaughlin
- Department of Microbiology, Genetics, and Immunology, Michigan State University, East Lansing, MI, USA.
| | - Miriam Miyagi
- Center for Computational Molecular Biology, Brown University, Providence, RI, USA
| | - Bittu Rajaraman
- Departments of Biology and Psychology, Ashoka University, Sonipat, Haryana, India
| | - Fátima Sancheznieto
- Institute for Clinical and Translational Research, University of Wisconsin-Madison, Madison, WI, USA
| | - Ayden I Scheim
- Epidemiology and Biostatistics, Drexel University, Philadelphia, PA, USA
| | - Simón E D Sun
- Center for Applied Transgender Studies, Chicago, IL, USA; Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA.
| | - F Dylan Titmuss
- Department of Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - Reubs J Walsh
- Center for Applied Transgender Studies, Chicago, IL, USA; Department of Psychology, Faculty of Arts & Sciences, University of Toronto, Toronto, ON, Canada
| | - Zara Y Weinberg
- Department of Biochemistry & Biophysics, UCSF, San Francisco, CA, USA
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3
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Suen KM, Sheard TM, Lin CC, Milonaityte D, Jayasinghe I, Ladbury JE. Correction: Expansion microscopy reveals subdomains in C. elegans germ granules. Life Sci Alliance 2024; 7:e202302405. [PMID: 37813490 PMCID: PMC10561762 DOI: 10.26508/lsa.202302405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 10/02/2023] [Indexed: 10/12/2023] Open
Abstract
Correction to Materials and Methods.
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Affiliation(s)
- Kin M Suen
- https://ror.org/024mrxd33 School of Molecular and Cellular Biology, University of Leeds, Leeds, UK
| | | | - Chi-Chuan Lin
- https://ror.org/024mrxd33 School of Molecular and Cellular Biology, University of Leeds, Leeds, UK
| | - Dovile Milonaityte
- https://ror.org/024mrxd33 School of Molecular and Cellular Biology, University of Leeds, Leeds, UK
| | - Izzy Jayasinghe
- School of Biosciences, University of Sheffield, Sheffield, UK
| | - John E Ladbury
- https://ror.org/024mrxd33 School of Molecular and Cellular Biology, University of Leeds, Leeds, UK
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4
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Hurley ME, Shah SS, Sheard TMD, Kirton HM, Steele DS, Gamper N, Jayasinghe I. Super-Resolution Analysis of the Origins of the Elementary Events of ER Calcium Release in Dorsal Root Ganglion Neurons. Cells 2023; 13:38. [PMID: 38201242 PMCID: PMC10778190 DOI: 10.3390/cells13010038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 12/18/2023] [Accepted: 12/21/2023] [Indexed: 01/12/2024] Open
Abstract
Coordinated events of calcium (Ca2+) released from the endoplasmic reticulum (ER) are key second messengers in excitable cells. In pain-sensing dorsal root ganglion (DRG) neurons, these events can be observed as Ca2+ sparks, produced by a combination of ryanodine receptors (RyR) and inositol 1,4,5-triphosphate receptors (IP3R1). These microscopic signals offer the neuronal cells with a possible means of modulating the subplasmalemmal Ca2+ handling, initiating vesicular exocytosis. With super-resolution dSTORM and expansion microscopies, we visualised the nanoscale distributions of both RyR and IP3R1 that featured loosely organised clusters in the subplasmalemmal regions of cultured rat DRG somata. We adapted a novel correlative microscopy protocol to examine the nanoscale patterns of RyR and IP3R1 in the locality of each Ca2+ spark. We found that most subplasmalemmal sparks correlated with relatively small groups of RyR whilst larger sparks were often associated with larger groups of IP3R1. These data also showed spontaneous Ca2+ sparks in <30% of the subplasmalemmal cell area but consisted of both these channel species at a 3.8-5 times higher density than in nonactive regions of the cell. Taken together, these observations reveal distinct patterns and length scales of RyR and IP3R1 co-clustering at contact sites between the ER and the surface plasmalemma that encode the positions and the quantity of Ca2+ released at each Ca2+ spark.
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Affiliation(s)
- Miriam E. Hurley
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Shihab S. Shah
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Thomas M. D. Sheard
- School of Biosciences, Faculty of Science, The University of Sheffield, Sheffield S10 2TN, UK
| | - Hannah M. Kirton
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Derek S. Steele
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Nikita Gamper
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Izzy Jayasinghe
- School of Biosciences, Faculty of Science, The University of Sheffield, Sheffield S10 2TN, UK
- EMBL Australia Node in Single Molecule Science, School of Biomedical Science, University of New South Wales, Kensington, Sydney 2052, Australia
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5
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Sheard TMD, Shakespeare TB, Seehra RS, Spencer ME, Suen KM, Jayasinghe I. Differential labelling of human sub-cellular compartments with fluorescent dye esters and expansion microscopy. Nanoscale 2023; 15:18489-18499. [PMID: 37942554 PMCID: PMC10667587 DOI: 10.1039/d3nr01129a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 10/07/2023] [Indexed: 11/10/2023]
Abstract
Amine-reactive esters of aromatic fluorescent dyes are emerging as imaging probes for nondescript staining of cellular and tissue architectures. We characterised the staining patterns of 14 fluorescent dye ester species with varying physical and spectral properties in the broadly studied human HeLa cell line. When combined with the super-resolution technique expansion microscopy (ExM) involving swellable acrylamide hydrogels, fluorescent esters reveal nanoscale features including cytoplasmic membrane-bound compartments and nucleolar densities. We observe differential labelling patterns linked to the biochemical properties of the conjugated dye. Alterations in staining density and compartment specificity were seen depending on the timepoint of application in the ExM protocol. Additional complexity in labelling patterns was detected arising from inter-ester interactions. Our findings raise a number of considerations for the use of fluorescent esters. We demonstrate esters as a useful addition to the repertoire of stains of the cellular proteome, whether applied either on their own to visualise overall cellular morphology, or as counterstains providing ultrastructural context alongside specific target markers like antibodies.
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Affiliation(s)
- Thomas M D Sheard
- School of Biosciences, Faculty of Science, University of Sheffield, Sheffield S10 2TN, UK.
| | - Tayla B Shakespeare
- School of Biosciences, Faculty of Science, University of Sheffield, Sheffield S10 2TN, UK.
| | - Rajpinder S Seehra
- School of Biosciences, Faculty of Science, University of Sheffield, Sheffield S10 2TN, UK.
| | - Michael E Spencer
- School of Biosciences, Faculty of Science, University of Sheffield, Sheffield S10 2TN, UK.
| | - Kin M Suen
- School of Molecular and Cellular Biology, University of Leeds, LS2 9JT, UK
| | - Izzy Jayasinghe
- School of Biosciences, Faculty of Science, University of Sheffield, Sheffield S10 2TN, UK.
- EMBL Australia Node in Single Molecule Science, School of Biomedical Sciences, University of New South Wales, Sydney, Australia.
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6
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Hurley ME, White E, Sheard TMD, Steele D, Jayasinghe I. Correlative super-resolution analysis of cardiac calcium sparks and their molecular origins in health and disease. Open Biol 2023; 13:230045. [PMID: 37220792 PMCID: PMC10205181 DOI: 10.1098/rsob.230045] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Accepted: 04/28/2023] [Indexed: 05/25/2023] Open
Abstract
Rapid release of calcium from internal stores via ryanodine receptors (RyRs) is one of the fastest types of cytoplasmic second messenger signalling in excitable cells. In the heart, rapid summation of the elementary events of calcium release, 'calcium sparks', determine the contraction of the myocardium. We adapted a correlative super-resolution microscopy protocol to correlate sub-plasmalemmal spontaneous calcium sparks in rat right ventricular myocytes with the local nanoscale RyR2 positions. This revealed a steep relationship between the integral of a calcium spark and the sum of the local RyR2s. Segmentation of recurring spark sites showed evidence of repeated and triggered saltatory activation of multiple local RyR2 clusters. In myocytes taken from failing right ventricles, RyR2 clusters themselves showed a dissipated morphology and fragmented (smaller) clusters. They also featured greater heterogeneity in both the spark properties and the relationship between the integral of the calcium spark and the local ensemble of RyR2s. While fragmented (smaller) RyR2 clusters were rarely observed directly underlying the larger sparks or the recurring spark sites, local interrogation of the channel-to-channel distances confirmed a clear link between the positions of each calcium spark and the tight, non-random clustering of the local RyR2 in both healthy and failing ventricles.
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Affiliation(s)
- Miriam E. Hurley
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Ed White
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Thomas M. D. Sheard
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
- School of Biosciences, Faculty of Science, The University of Sheffield, Sheffield S10 2TN, UK
| | - Derek Steele
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Izzy Jayasinghe
- School of Biosciences, Faculty of Science, The University of Sheffield, Sheffield S10 2TN, UK
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7
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Suen KM, Sheard TM, Lin CC, Milonaityte D, Jayasinghe I, Ladbury JE. Expansion microscopy reveals subdomains in C. elegans germ granules. Life Sci Alliance 2023; 6:e202201650. [PMID: 36750365 PMCID: PMC9905708 DOI: 10.26508/lsa.202201650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 01/25/2023] [Accepted: 01/26/2023] [Indexed: 02/09/2023] Open
Abstract
Light and electron microscopy techniques have been indispensable in the identification and characterization of liquid-liquid phase separation membraneless organelles. However, for complex membraneless organelles such as the perinuclear germ granule in C. elegans, our understanding of how the intact organelle is regulated is hampered by (1) technical limitations in confocal fluorescence imaging for the simultaneous examination of multiple granule protein markers and (2) inaccessibility of electron microscopy. We take advantage of the newly developed super resolution method of expansion microscopy (ExM) and in situ staining of the whole proteome to examine the C. elegans germ granule, the P granule. We show that in small RNA pathway mutants, the P granule is smaller compared with WT animals. Furthermore, we investigate the relationship between the P granule and two other germ granules, Mutator foci and Z granule, and show that they are located within the same protein-dense regions while occupying distinct subdomains within this ultrastructure. This study will serve as an important tool in our understanding of germ granule biology and the biological role of liquid-liquid phase separation.
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Affiliation(s)
- Kin M Suen
- School of Molecular and Cellular Biology, University of Leeds, Leeds, UK
| | | | - Chi-Chuan Lin
- School of Molecular and Cellular Biology, University of Leeds, Leeds, UK
| | - Dovile Milonaityte
- School of Molecular and Cellular Biology, University of Leeds, Leeds, UK
| | - Izzy Jayasinghe
- School of Biosciences, University of Sheffield, Sheffield, UK
| | - John E Ladbury
- School of Molecular and Cellular Biology, University of Leeds, Leeds, UK
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8
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Sheard TMD, Hurley ME, Smith AJ, Colyer J, White E, Jayasinghe I. Three-dimensional visualization of the cardiac ryanodine receptor clusters and the molecular-scale fraying of dyads. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210316. [PMID: 36189802 PMCID: PMC9527906 DOI: 10.1098/rstb.2021.0316] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Clusters of ryanodine receptor calcium channels (RyRs) form the primary molecular machinery of intracellular calcium signalling in cardiomyocytes. While a range of optical super-resolution microscopy techniques have revealed the nanoscale structure of these clusters, the three-dimensional (3D) nanoscale topologies of the clusters have remained mostly unresolved. In this paper, we demonstrate the exploitation of molecular-scale resolution in enhanced expansion microscopy (EExM) along with various 2D and 3D visualization strategies to observe the topological complexities, geometries and molecular sub-domains within the RyR clusters. Notably, we observed sub-domains containing RyR-binding protein junctophilin-2 (JPH2) occupying the central regions of RyR clusters in the deeper interior of the myocytes (including dyads), while the poles were typically devoid of JPH2, lending to a looser RyR arrangement. By contrast, peripheral RyR clusters exhibited variable co-clustering patterns and ratios between RyR and JPH2. EExM images of dyadic RyR clusters in right ventricular (RV) myocytes isolated from rats with monocrotaline-induced RV failure revealed hallmarks of RyR cluster fragmentation accompanied by breaches in the JPH2 sub-domains. Frayed RyR patterns observed adjacent to these constitute new evidence that the destabilization of the RyR arrays inside the JPH2 sub-domains may seed the primordial foci of dyad remodelling observed in heart failure. This article is part of the theme issue 'The cardiomyocyte: new revelations on the interplay between architecture and function in growth, health, and disease'.
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Affiliation(s)
- Thomas M D Sheard
- School of Biosciences, Faculty of Science, University of Sheffield, Sheffield S10 2TN, UK.,School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Miriam E Hurley
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Andrew J Smith
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - John Colyer
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Ed White
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Izzy Jayasinghe
- School of Biosciences, Faculty of Science, University of Sheffield, Sheffield S10 2TN, UK.,School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
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9
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Holmes M, Hurley ME, Sheard TMD, Benson AP, Jayasinghe I, Colman MA. Increased SERCA2a sub-cellular heterogeneity in right-ventricular heart failure inhibits excitation-contraction coupling and modulates arrhythmogenic dynamics. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210317. [PMID: 36189801 PMCID: PMC9527927 DOI: 10.1098/rstb.2021.0317] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 12/21/2021] [Indexed: 12/14/2022] Open
Abstract
The intracellular calcium handling system of cardiomyocytes is responsible for controlling excitation-contraction coupling (ECC) and has been linked to pro-arrhythmogenic cellular phenomena in conditions such as heart failure (HF). SERCA2a, responsible for intracellular uptake, is a primary regulator of calcium homeostasis, and remodelling of its function has been proposed as a causal factor underlying cellular and tissue dysfunction in disease. Whereas adaptations to the global (i.e. whole-cell) expression of SERCA2a have been previously investigated in the context of multiple diseases, the role of its spatial profile in the sub-cellular volume has yet to be elucidated. We present an approach to characterize the sub-cellular heterogeneity of SERCA2a and apply this approach to quantify adaptations to the length-scale of heterogeneity (the distance over which expression is correlated) associated with right-ventricular (RV)-HF. These characterizations informed simulations to predict the functional implications of this heterogeneity, and its remodelling in disease, on ECC, the dynamics of calcium-transient alternans and the emergence of spontaneous triggered activity. Image analysis reveals that RV-HF is associated with an increase in length-scale and its inter-cellular variability; simulations predict that this increase in length-scale can reduce ECC and critically modulate the vulnerability to both alternans and triggered activity. This article is part of the theme issue 'The cardiomyocyte: new revelations on the interplay between architecture and function in growth, health, and disease'.
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Affiliation(s)
- M. Holmes
- Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - M. E. Hurley
- School of Biomedical Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - T. M. D. Sheard
- School of Biosciences, The University of Sheffield, Sheffield S10 2TN, UK
| | - A. P. Benson
- Institute of Membrane and Systems Biology, University of Leeds, Leeds LS2 9JT, UK
| | - I. Jayasinghe
- School of Biomedical Sciences, University of Leeds, Leeds LS2 9JT, UK
- School of Biosciences, The University of Sheffield, Sheffield S10 2TN, UK
| | - M. A. Colman
- Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
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10
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Jebsen JM, Nicoll Baines K, Oliver RA, Jayasinghe I. Dismantling barriers faced by women in STEM. Nat Chem 2022; 14:1203-1206. [DOI: 10.1038/s41557-022-01072-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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11
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Bristow RG, Engel J, Jayasinghe I, Kampmann M, James Sansom O, Bryant DM. Conversations with LGBT+ scientists about visibility, leadership and climbing the career ladder. J Cell Sci 2022; 135:274462. [DOI: 10.1242/jcs.259880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
ABSTRACT
February is LGBT+ history month, and to celebrate, Journal of Cell Science Editorial Advisory Board member David Bryant organised a conversation with a selection of scientists to explore their experiences of being LGBT+ in academia.
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Affiliation(s)
- Robert G. Bristow
- CRUK Manchester Institute and Manchester Cancer Research Centre, University of Manchester, Manchester M20 4GJ, UK
| | - Joanne Engel
- Department of Medicine, and Department of Microbiology and Immunology, University of California, San Francisco, CA 94143, USA
| | - Izzy Jayasinghe
- Division of Molecular & Cellular Biology, School of Biosciences, The University of Sheffield, Sheffield S10 2TN, UK
| | - Martin Kampmann
- Institute for Neurodegenerative Diseases, Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Owen James Sansom
- Cancer Research UK Beatson Institute, Glasgow G61 1BD, UK
- Institute of Cancer Sciences, The University of Glasgow, Glasgow G61 1QH, UK
| | - David M. Bryant
- Cancer Research UK Beatson Institute, Glasgow G61 1BD, UK
- Institute of Cancer Sciences, The University of Glasgow, Glasgow G61 1QH, UK
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12
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Hurley ME, Sheard TMD, Norman R, Kirton HM, Shah SS, Pervolaraki E, Yang Z, Gamper N, White E, Steele D, Jayasinghe I. A correlative super-resolution protocol to visualise structural underpinnings of fast second-messenger signalling in primary cell types. Methods 2021; 193:27-37. [PMID: 33059034 DOI: 10.1016/j.ymeth.2020.10.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 09/28/2020] [Accepted: 10/07/2020] [Indexed: 10/24/2022] Open
Abstract
Nanometre-scale cellular information obtained through super-resolution microscopies are often unaccompanied by functional information, particularly transient and diffusible signals through which life is orchestrated in the nano-micrometre spatial scale. We describe a correlative imaging protocol which allows the ubiquitous intracellular second messenger, calcium (Ca2+), to be directly visualised against nanoscale patterns of the ryanodine receptor (RyR) Ca2+ channels which give rise to these Ca2+ signals in wildtype primary cells. This was achieved by combining total internal reflection fluorescence (TIRF) imaging of the elementary Ca2+ signals, with the subsequent DNA-PAINT imaging of the RyRs. We report a straightforward image analysis protocol of feature extraction and image alignment between correlative datasets and demonstrate how such data can be used to visually identify the ensembles of Ca2+ channels that are locally activated during the genesis of cytoplasmic Ca2+ signals.
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Affiliation(s)
- Miriam E Hurley
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, LS2 9JT, UK
| | - Thomas M D Sheard
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, LS2 9JT, UK
| | - Ruth Norman
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, LS2 9JT, UK
| | - Hannah M Kirton
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, LS2 9JT, UK
| | - Shihab S Shah
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, LS2 9JT, UK
| | - Eleftheria Pervolaraki
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, LS2 9JT, UK
| | - Zhaokang Yang
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, LS2 9JT, UK
| | - Nikita Gamper
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, LS2 9JT, UK
| | - Ed White
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, LS2 9JT, UK
| | - Derek Steele
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, LS2 9JT, UK
| | - Izzy Jayasinghe
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, LS2 9JT, UK; Department of Molecular Biology and Biotechnology, Faculty of Science, The University of Sheffield, S10 2TN, UK.
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13
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Armada-Moreira A, Cizauskas C, Fleury G, Forslund SK, Guthman EM, Hanafiah A, Hope JM, Jayasinghe I, McSweeney D, Young ID. STEM Pride: Perspectives from transgender, nonbinary, and genderqueer scientists. Cell 2021; 184:3352-3355. [PMID: 34171316 DOI: 10.1016/j.cell.2021.05.043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
In celebration of Pride Month, we asked transgender, genderqueer, and nonbinary scientists to tell us about what fascinates them, their ambitions and achievements, and how their gender identities have shaped their experiences in STEM. We owe a special thanks to 500 Queer Scientists (https://500queerscientists.com/), whose network and efforts at increasing LGBTQ+ scientists' visibility made this article possible.
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14
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Colman MA, Holmes M, Whittaker DG, Jayasinghe I, Benson AP. Multi-scale approaches for the simulation of cardiac electrophysiology: I - Sub-cellular and stochastic calcium dynamics from cell to organ. Methods 2020; 185:49-59. [PMID: 32126258 DOI: 10.1016/j.ymeth.2020.02.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 02/14/2020] [Accepted: 02/26/2020] [Indexed: 12/15/2022] Open
Abstract
Computational models of the heart at multiple spatial scales, from sub-cellular nanodomains to the whole-organ, are a powerful tool for the simulation of cardiac electrophysiology. Application of these models has provided remarkable insight into the normal and pathological functioning of the heart. In these two articles, we present methods for modelling cardiac electrophysiology at all of these spatial scales. In part one, presented here, we discuss methods and approaches for modelling sub-cellular calcium dynamics at the whole-cell and organ scales, valuable for modelling excitation-contraction coupling and mechanisms of arrhythmia triggers.
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Affiliation(s)
- Michael A Colman
- School of Biomedical Sciences, University of Leeds, Leeds LS2 9JT, UK.
| | - Maxx Holmes
- School of Biomedical Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Dominic G Whittaker
- School of Biomedical Sciences, University of Leeds, Leeds LS2 9JT, UK; School of Mathematical Sciences, University of Nottingham, Nottingham NG7 2RD, UK
| | - Izzy Jayasinghe
- School of Biomedical Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Alan P Benson
- School of Biomedical Sciences, University of Leeds, Leeds LS2 9JT, UK
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15
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Hurley ME, Sheard TM, Norman R, Kirton HM, Shah SS, Pervolaraki E, Yang Z, Steele DS, Gamper N, White E, Jayasinghe I. Optical Superresolution Analysis of Intracellular Calcium Handling Proteins and Correlating Calcium Signal Morphology. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.1054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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16
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Miteva KT, Pedicini L, Wilson LA, Jayasinghe I, Slip RG, Marszalek K, Gaunt HJ, Bartoli F, Deivasigamani S, Sobradillo D, Beech DJ, McKeown L. Rab46 integrates Ca 2+ and histamine signaling to regulate selective cargo release from Weibel-Palade bodies. J Cell Biol 2019; 218:2232-2246. [PMID: 31092558 PMCID: PMC6605797 DOI: 10.1083/jcb.201810118] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 03/24/2019] [Accepted: 04/22/2019] [Indexed: 12/12/2022] Open
Abstract
It is unclear how a plethora of stimuli evoke differential cargo secretion from endothelial cells to produce stimulus-appropriate responses. Miteva et al. show that Rab46 integrates histamine signaling and Ca2+ signals to regulate selective cargo release from Weibel-Palade bodies. Endothelial cells selectively release cargo stored in Weibel-Palade bodies (WPBs) to regulate vascular function, but the underlying mechanisms are poorly understood. Here we show that histamine evokes the release of the proinflammatory ligand, P-selectin, while diverting WPBs carrying non-inflammatory cargo away from the plasma membrane to the microtubule organizing center. This differential trafficking is dependent on Rab46 (CRACR2A), a newly identified Ca2+-sensing GTPase, which localizes to a subset of P-selectin–negative WPBs. After acute stimulation of the H1 receptor, GTP-bound Rab46 evokes dynein-dependent retrograde transport of a subset of WPBs along microtubules. Upon continued histamine stimulation, Rab46 senses localized elevations of intracellular calcium and evokes dispersal of microtubule organizing center–clustered WPBs. These data demonstrate for the first time that a Rab GTPase, Rab46, integrates G protein and Ca2+ signals to couple on-demand histamine signals to selective WPB trafficking.
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Affiliation(s)
- Katarina T Miteva
- Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - Lucia Pedicini
- Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - Lesley A Wilson
- Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - Izzy Jayasinghe
- Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Raphael G Slip
- Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - Katarzyna Marszalek
- Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - Hannah J Gaunt
- Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - Fiona Bartoli
- Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - Shruthi Deivasigamani
- Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - Diego Sobradillo
- Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - David J Beech
- Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - Lynn McKeown
- Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
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17
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Sheard TD, Hurley ME, Colyer J, White E, Norman R, Pervolaraki E, Narayanasamy KK, Hou Y, Kirton HM, Yang Z, Hunter L, Shim JU, Clowsley AH, Smith AJ, Baddeley D, Soeller C, Colman MA, Jayasinghe I. Three-Dimensional and Chemical Mapping of Intracellular Signaling Nanodomains in Health and Disease with Enhanced Expansion Microscopy. ACS Nano 2019; 13:2143-2157. [PMID: 30715853 PMCID: PMC6396323 DOI: 10.1021/acsnano.8b08742] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 02/04/2019] [Indexed: 05/08/2023]
Abstract
Nanodomains are intracellular foci which transduce signals between major cellular compartments. One of the most ubiquitous signal transducers, the ryanodine receptor (RyR) calcium channel, is tightly clustered within these nanodomains. Super-resolution microscopy has previously been used to visualize RyR clusters near the cell surface. A majority of nanodomains located deeper within cells have remained unresolved due to limited imaging depths and axial resolution of these modalities. A series of enhancements made to expansion microscopy allowed individual RyRs to be resolved within planar nanodomains at the cell periphery and the curved nanodomains located deeper within the interiors of cardiomyocytes. With a resolution of ∼ 15 nm, we localized both the position of RyRs and their individual phosphorylation for the residue Ser2808. With a three-dimensional imaging protocol, we observed disturbances to the RyR arrays in the nanometer scale which accompanied right-heart failure caused by pulmonary hypertension. The disease coincided with a distinct gradient of RyR hyperphosphorylation from the edge of the nanodomain toward the center, not seen in healthy cells. This spatial profile appeared to contrast distinctly from that sustained by the cells during acute, physiological hyperphosphorylation when they were stimulated with a β-adrenergic agonist. Simulations of RyR arrays based on the experimentally determined channel positions and phosphorylation signatures showed how the nanoscale dispersal of the RyRs during pathology diminishes its intrinsic likelihood to ignite a calcium signal. It also revealed that the natural topography of RyR phosphorylation could offset potential heterogeneity in nanodomain excitability which may arise from such RyR reorganization.
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Affiliation(s)
- Thomas
M. D. Sheard
- School
of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Miriam E. Hurley
- School
of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - John Colyer
- School
of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Ed White
- School
of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Ruth Norman
- School
of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Eleftheria Pervolaraki
- School
of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Kaarjel K. Narayanasamy
- School
of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Yufeng Hou
- Institute
of Experimental Medical Research, Oslo University
Hospital Ullevål, Oslo 0407, Norway
| | - Hannah M. Kirton
- School
of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Zhaokang Yang
- School
of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Liam Hunter
- School
of Physics and Astronomy, Faculty of Mathematics and Physical Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Jung-uk Shim
- School
of Physics and Astronomy, Faculty of Mathematics and Physical Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
| | | | - Andrew J. Smith
- School
of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - David Baddeley
- Auckland
Bioengineering Institute, University of
Auckland, UniServices
House, Level, 6/70 Symonds St, Grafton, Auckland 1010, New Zealand
| | - Christian Soeller
- Living
Systems Institute, University of Exeter, Devon EX4 4QL, United Kingdom
| | - Michael A. Colman
- School
of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Izzy Jayasinghe
- School
of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
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18
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Jayasinghe I, Clowsley AH, de Langen O, Sali SS, Crossman DJ, Soeller C. Shining New Light on the Structural Determinants of Cardiac Couplon Function: Insights From Ten Years of Nanoscale Microscopy. Front Physiol 2018; 9:1472. [PMID: 30405432 PMCID: PMC6204384 DOI: 10.3389/fphys.2018.01472] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 09/28/2018] [Indexed: 12/12/2022] Open
Abstract
Remodelling of the membranes and protein clustering patterns during the pathogenesis of cardiomyopathies has renewed the interest in spatial visualisation of these structures in cardiomyocytes. Coincidental emergence of single molecule (super-resolution) imaging and tomographic electron microscopy tools in the last decade have led to a number of new observations on the structural features of the couplons, the primary sites of excitation-contraction coupling in the heart. In particular, super-resolution and tomographic electron micrographs have revised and refined the classical views of the nanoscale geometries of couplons, t-tubules and the organisation of the principal calcium handling proteins in both healthy and failing hearts. These methods have also allowed the visualisation of some features which were too small to be detected with conventional microscopy tools. With new analytical capabilities such as single-protein mapping, in situ protein quantification, correlative and live cell imaging we are now observing an unprecedented interest in adapting these research tools across the cardiac biophysical research discipline. In this article, we review the depth of the new insights that have been enabled by these tools toward understanding the structure and function of the cardiac couplon. We outline the major challenges that remain in these experiments and emerging avenues of research which will be enabled by these technologies.
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Affiliation(s)
- Izzy Jayasinghe
- Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | | | - Oscar de Langen
- Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Sonali S Sali
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India
| | - David J Crossman
- Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Christian Soeller
- Living Systems Institute, University of Exeter, Exeter, United Kingdom
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19
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Jayasinghe I, Clowsley AH, Lin R, Lutz T, Harrison C, Green E, Baddeley D, Di Michele L, Soeller C. True Molecular Scale Visualization of Variable Clustering Properties of Ryanodine Receptors. Cell Rep 2018; 22:557-567. [PMID: 29320748 PMCID: PMC5775502 DOI: 10.1016/j.celrep.2017.12.045] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 11/17/2017] [Accepted: 12/12/2017] [Indexed: 11/25/2022] Open
Abstract
Signaling nanodomains rely on spatial organization of proteins to allow controlled intracellular signaling. Examples include calcium release sites of cardiomyocytes where ryanodine receptors (RyRs) are clustered with their molecular partners. Localization microscopy has been crucial to visualizing these nanodomains but has been limited by brightness of markers, restricting the resolution and quantification of individual proteins clustered within. Harnessing the remarkable localization precision of DNA-PAINT (<10 nm), we visualized punctate labeling within these nanodomains, confirmed as single RyRs. RyR positions within sub-plasmalemmal nanodomains revealed how they are organized randomly into irregular clustering patterns leaving significant gaps occupied by accessory or regulatory proteins. RyR-inhibiting protein junctophilin-2 appeared highly concentrated adjacent to RyR channels. Analyzing these molecular maps showed significant variations in the co-clustering stoichiometry between junctophilin-2 and RyR, even between nearby nanodomains. This constitutes an additional level of complexity in RyR arrangement and regulation of calcium signaling, intrinsically built into the nanodomains.
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Affiliation(s)
- Izzy Jayasinghe
- Faculty of Biological Sciences, University of Leeds, Leeds, UK; Living Systems Institute, University of Exeter, Exeter, UK
| | | | - Ruisheng Lin
- Living Systems Institute, University of Exeter, Exeter, UK
| | - Tobias Lutz
- Living Systems Institute, University of Exeter, Exeter, UK
| | - Carl Harrison
- Living Systems Institute, University of Exeter, Exeter, UK
| | - Ellen Green
- Living Systems Institute, University of Exeter, Exeter, UK
| | - David Baddeley
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
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20
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Cully TR, Murphy RM, Roberts L, Raastad T, Fassett RG, Coombes JS, Jayasinghe I, Launikonis BS. Human skeletal muscle plasmalemma alters its structure to change its Ca 2+-handling following heavy-load resistance exercise. Nat Commun 2017; 8:14266. [PMID: 28193999 PMCID: PMC5316829 DOI: 10.1038/ncomms14266] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 12/08/2016] [Indexed: 01/30/2023] Open
Abstract
High-force eccentric exercise results in sustained increases in cytoplasmic Ca2+ levels ([Ca2+]cyto), which can cause damage to the muscle. Here we report that a heavy-load strength training bout greatly alters the structure of the membrane network inside the fibres, the tubular (t-) system, causing the loss of its predominantly transverse organization and an increase in vacuolation of its longitudinal tubules across adjacent sarcomeres. The transverse tubules and vacuoles displayed distinct Ca2+-handling properties. Both t-system components could take up Ca2+ from the cytoplasm but only transverse tubules supported store-operated Ca2+ entry. The retention of significant amounts of Ca2+ within vacuoles provides an effective mechanism to reduce the total content of Ca2+ within the fibre cytoplasm. We propose this ability can reduce or limit resistance exercise-induced, Ca2+-dependent damage to the fibre by the reduction of [Ca2+]cyto to help maintain fibre viability during the period associated with delayed onset muscle soreness.
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Affiliation(s)
- Tanya R. Cully
- School of Biomedical Sciences, The University of Queensland,
Brisbane, Queensland
4072, Australia
| | - Robyn M. Murphy
- Department of Biochemistry & Genetics, La Trobe Institute for
Molecular Science, La Trobe University, Melbourne, Victoria
3086, Australia
| | - Llion Roberts
- School of Human Movement and Nutritional Sciences, The University of
Queensland, Brisbane, Queensland
4072, Australia
- Centre of Excellence for Applied Sport Science Research, Queensland
Academy of Sport, Brisbane, Queensland
4111, Australia
| | - Truls Raastad
- Norwegian School of Sport Sciences, Oslo
N-0806, Norway
| | - Robert G. Fassett
- School of Human Movement and Nutritional Sciences, The University of
Queensland, Brisbane, Queensland
4072, Australia
| | - Jeff S. Coombes
- School of Human Movement and Nutritional Sciences, The University of
Queensland, Brisbane, Queensland
4072, Australia
| | - Izzy Jayasinghe
- School of Biomedical Sciences, The University of Queensland,
Brisbane, Queensland
4072, Australia
- School of Biomedical Sciences, University of Leeds,
Leeds
LS2 9JT, UK
| | - Bradley S. Launikonis
- School of Biomedical Sciences, The University of Queensland,
Brisbane, Queensland
4072, Australia
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21
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Munro ML, Jayasinghe I, Wang Q, Quick A, Wang W, Baddeley D, Wehrens XHT, Soeller C. Junctophilin-2 in the nanoscale organisation and functional signalling of ryanodine receptor clusters in cardiomyocytes. J Cell Sci 2016; 129:4388-4398. [PMID: 27802169 PMCID: PMC5201013 DOI: 10.1242/jcs.196873] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 10/14/2016] [Indexed: 11/20/2022] Open
Abstract
Signalling nanodomains requiring close contact between the plasma membrane and internal compartments, known as 'junctions', are fast communication hubs within excitable cells such as neurones and muscle. Here, we have examined two transgenic murine models probing the role of junctophilin-2, a membrane-tethering protein crucial for the formation and molecular organisation of sub-microscopic junctions in ventricular muscle cells of the heart. Quantitative single-molecule localisation microscopy showed that junctions in animals producing above-normal levels of junctophilin-2 were enlarged, allowing the re-organisation of the primary functional protein within it, the ryanodine receptor (RyR; in this paper, we use RyR to refer to the myocardial isoform RyR2). Although this change was associated with much enlarged RyR clusters that, due to their size, should be more excitable, functionally it caused a mild inhibition in the Ca2+ signalling output of the junctions (Ca2+ sparks). Analysis of the single-molecule densities of both RyR and junctophilin-2 revealed an ∼3-fold increase in the junctophilin-2 to RyR ratio. This molecular rearrangement is compatible with direct inhibition of RyR opening by junctophilin-2 to intrinsically stabilise the Ca2+ signalling properties of the junction and thus the contractile function of the cell.
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Affiliation(s)
- Michelle L Munro
- Department of Physiology, School of Medical Sciences, University of Auckland, 1023, New Zealand
| | - Izzy Jayasinghe
- School of Physics, University of Exeter, Exeter EX4 4QL, UK
- School of Biomedical Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Qiongling Wang
- Cardiovascular Research Institute, Departments of Molecular Physiology and Biophysics, Medicine (Cardiology), and Pediatrics (Cardiology), Baylor College of Medicine, Houston, TX 77030, USA
| | - Ann Quick
- Cardiovascular Research Institute, Departments of Molecular Physiology and Biophysics, Medicine (Cardiology), and Pediatrics (Cardiology), Baylor College of Medicine, Houston, TX 77030, USA
| | - Wei Wang
- Cardiovascular Research Institute, Departments of Molecular Physiology and Biophysics, Medicine (Cardiology), and Pediatrics (Cardiology), Baylor College of Medicine, Houston, TX 77030, USA
| | - David Baddeley
- Department of Cell Biology, Yale University, New Haven, CT 06520, USA
| | - Xander H T Wehrens
- Cardiovascular Research Institute, Departments of Molecular Physiology and Biophysics, Medicine (Cardiology), and Pediatrics (Cardiology), Baylor College of Medicine, Houston, TX 77030, USA
| | - Christian Soeller
- Department of Physiology, School of Medical Sciences, University of Auckland, 1023, New Zealand
- School of Physics, University of Exeter, Exeter EX4 4QL, UK
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22
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Crossman DJ, Hou Y, Jayasinghe I, Baddeley D, Soeller C. Combining confocal and single molecule localisation microscopy: A correlative approach to multi-scale tissue imaging. Methods 2015; 88:98-108. [PMID: 25814438 DOI: 10.1016/j.ymeth.2015.03.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 03/05/2015] [Accepted: 03/18/2015] [Indexed: 10/23/2022] Open
Abstract
Many biological questions require information at different spatial scales that include molecular, organelle, cell and tissue scales. Here we detail a method of multi-scale imaging of human cardiac tissue by correlatively combining nano-scale data of direct stochastic optical reconstruction microscopy (dSTORM) with cellular and tissue level data provided by confocal microscopy. By utilising conventional fluorescence dyes the same cellular structures can be imaged with both modalities. Human cardiac tissue was first imaged at the nanoscale to identify macro-molecular membrane complexes containing the cardiac muscle proteins junctophilin (JPH) and the ryanodine receptor (RyR). The distribution of these proteins and an additional cell membrane marker (wheat germ agglutinin, WGA) were subsequently imaged by confocal microscopy. By segmenting dSTORM data into membrane and non-membrane components we demonstrate increased colocalization of RyR with JPH at the plasma-membrane as compared to intracellular compartments. Strategies for antibody labelling, quality control, locating and aligning structures between modalities, and analysis of combined multi-scaled data sets are described.
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Affiliation(s)
- David J Crossman
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Yufeng Hou
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | | | - David Baddeley
- Department of Physiology, University of Auckland, Auckland, New Zealand; Department of Cell Biology, Yale University, New Haven, USA
| | - Christian Soeller
- Department of Physiology, University of Auckland, Auckland, New Zealand; Biomedical Physics, University of Exeter, UK.
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23
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Abstract
Skeletal muscle fibres are very large and elongated. In response to excitation there must be a rapid and uniform release of Ca(2+) throughout for contraction. To ensure a uniform spread of excitation throughout the fibre to all the Ca(2+) release sites, the muscle internalizes the plasma membrane, to form the tubular (t-) system. Hence the t-system forms a complex and dense network throughout the fibre that is responsible for excitation-contraction coupling and other signalling mechanisms. However, we currently do not have a very detailed view of this membrane network because of limitations in previously used imaging techniques to visualize it. In this study we serially imaged fluorescent dye trapped in the t-system of fibres from rat and toad muscle using the confocal microscope, and deconvolved and reconstructed these images to produce the first three-dimensional reconstructions of large volumes of the vertebrate t-system. These images showed complex arrangements of tubules that have not been described previously and also allowed the association of the t-system with cellular organelles to be visualized. There was a high density of tubules close to the nuclear envelope because of the close and parallel alignment of the long axes of the myofibrils and the nuclei. Furthermore local fluorescence intensity variations from sub-resolution tubules were converted to tubule diameters. Mean diameters of tubules were 85.9±6.6 and 91.2±8.2 nm, from rat and toad muscle under isotonic conditions, respectively. Under osmotic stress the distribution of tubular diameters shifted significantly in toad muscle only, with change specifically occurring in the transverse but not longitudinal tubules.
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Affiliation(s)
- Izzy Jayasinghe
- School of Biomedical Science, The University of Queensland, Brisbane, QLD 4072, Australia
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24
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Jayasinghe I, Lo H, Morgan G, Baddeley D, Parton R, Soeller C, Launikonis B. Examination of the subsarcolemmal tubular system of mammalian skeletal muscle fibers. Biophys J 2013; 104:L19-21. [PMID: 23746530 PMCID: PMC3672866 DOI: 10.1016/j.bpj.2013.04.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 04/02/2013] [Accepted: 04/16/2013] [Indexed: 11/26/2022] Open
Abstract
A subsarcolemmal tubular system network (SSTN) has been detected in skeletal muscle fibers by confocal imaging after the removal of the sarcolemma. Here we confirm the existence and resolve the fine architecture and the localization of the SSTN at an unprecedented level of detail by examining extracellularly applied tubular system markers in skeletal muscle fiber preparations with a combination of three imaging modalities: confocal fluorescence microscopy, direct stochastic optical reconstruction microscopy, and tomographic electron microscopy. Three-dimensional reconstructions showed that the SSTN was a dense two-dimensional network within the subsarcolemmal space around the fiber, running ~500-600 nm underneath and parallel to the sarcolemma. The SSTN is composed of tubules ~95 nm in width with ~60% of the tubules directed transversely and >30% directed longitudinally. The deeper regular transverse tubules located at each A-I boundary of the sarcomeres branched from the SSTN, indicating individual transverse tubules that form triads are continuous with, but do not directly contact the sarcolemma. This suggests that the SSTN plays an important role in affecting the exchange of deeper tubule lumina with the extracellular space.
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Affiliation(s)
- Izzy Jayasinghe
- School of Biomedical Sciences, Faculty of Science, The University of Queensland, Brisbane, Australia
| | - Harriet P. Lo
- School of Molecular and Microbial Sciences, The University of Queensland, Brisbane, Australia
| | - Garry P. Morgan
- Institute for Molecular Bioscience and Centre for Microscopy and Microanalysis, The University of Queensland, Brisbane, Australia
| | - David Baddeley
- School of Medical Sciences, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Department of Cell Biology, Yale University, New Haven
| | - Robert G. Parton
- School of Molecular and Microbial Sciences, The University of Queensland, Brisbane, Australia
| | - Christian Soeller
- School of Medical Sciences, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- School of Physics, The University of Exeter, United Kingdom
| | - Bradley S. Launikonis
- School of Biomedical Sciences, Faculty of Science, The University of Queensland, Brisbane, Australia
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25
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Jayasinghe I, Baddeley D, Kong C, Wehrens X, Cannell M, Soeller C. Nanoscale organization of junctophilin-2 and ryanodine receptors within peripheral couplings of rat ventricular cardiomyocytes. Biophys J 2012; 102:L19-21. [PMID: 22404946 PMCID: PMC3296050 DOI: 10.1016/j.bpj.2012.01.034] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Revised: 12/25/2011] [Accepted: 01/17/2012] [Indexed: 11/26/2022] Open
Abstract
The peripheral distributions of the cardiac ryanodine receptor (RyR) and a junctional protein, junctophilin-2 (JPH2), were examined using single fluorophore localization-based super-resolution microscopy in rat ventricular myocytes. JPH2 was strongly associated with RyR clusters. Estimates of the colocalizing fraction of JPH labeling with RyR was ~90% within 30 nm of RyR clusters. This is comparable to fractions estimated from confocal data (~87%). Similarly, most RyRs were associated with JPH2 labeling in super-resolution images (~81% within 30 nm of JPH2 clusters). The shape of associated RyR clusters and JPH2 clusters were very similar, but not identical, suggesting that JPH2 is dispersed throughout RyR clusters and that the packing of JPH2 into junctions and the assembly of RyR clusters are tightly linked.
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Affiliation(s)
- Izzy Jayasinghe
- Department of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
- School of Biomedical Sciences, University of Queensland, Brisbane, Australia
| | - David Baddeley
- Department of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - Cherrie H.T. Kong
- Department of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - Xander H.T. Wehrens
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas
| | - Mark B. Cannell
- Department of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
- Department of Physiology and Pharmacology, School of Medical Sciences, University of Bristol, Bristol, United Kingdom
| | - Christian Soeller
- Department of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
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Jayasinghe I, Cannell MB, Soeller C. Organization of ryanodine receptors, transverse tubules, and sodium-calcium exchanger in rat myocytes. Biophys J 2009; 97:2664-73. [PMID: 19917219 PMCID: PMC2776253 DOI: 10.1016/j.bpj.2009.08.036] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2009] [Revised: 08/12/2009] [Accepted: 08/13/2009] [Indexed: 10/20/2022] Open
Abstract
Confocal and total internal reflection fluorescence imaging was used to examine the distribution of caveolin-3, sodium-calcium exchange (NCX) and ryanodine receptors (RyRs) in rat ventricular myocytes. Transverse and longitudinal optical sectioning shows that NCX is distributed widely along the transverse and longitudinal tubular system (t-system). The NCX labeling consisted of both punctate and distributed components, which partially colocalize with RyRs (27%). Surface membrane labeling showed a similar pattern but the fraction of RyR clusters containing NCX label was decreased and no nonpunctate labeling was observed. Sixteen percent of RyRs were not colocalized with the t-system and 1.6% of RyRs were found on longitudinal elements of the t-system. The surface distribution of RyR labeling was not generally consistent with circular patches of RyRs. This suggests that previous estimates for the number of RyRs in a junction (based on circular close-packed arrays) need to be revised. The observed distribution of caveolin-3 labeling was consistent with its exclusion from RyR clusters. Distance maps for all colocalization pairs were calculated to give the distance between centroids of punctate labeling and edges for distributed components. The possible roles for punctate NCX labeling are discussed.
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Affiliation(s)
- Izzy Jayasinghe
- Department of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - Mark B. Cannell
- Department of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - Christian Soeller
- Department of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
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Baddeley D, Jayasinghe I, Cremer C, Cannell MB, Soeller C. Light-induced dark states of organic fluochromes enable 30 nm resolution imaging in standard media. Biophys J 2009; 96:L22-4. [PMID: 19167284 PMCID: PMC2716455 DOI: 10.1016/j.bpj.2008.11.002] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2008] [Accepted: 11/11/2008] [Indexed: 10/21/2022] Open
Abstract
We show that high quantum efficiency fluorophores can exhibit reversible photobleaching. This observation provides the basis for an imaging technique we call reversible photobleaching microscopy. We demonstrate applicability of this technique using antibody labeled biological samples in standard aqueous (or glycerol based) media to produce far-field images at approximately 30 nm resolution. Our novel method relies on intense illumination to reversibly induce a very long-lived (>10 s) dark state from which single fluorochromes slowly return stochastically. As in other localization microscopy methods, reversible photobleaching microscopy localizes single fluorochromes, but has the advantage that specialized photoactivatible and photoswitchable molecules or special immersion/embedding media are not required.
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Affiliation(s)
- David Baddeley
- Department of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - Izzy Jayasinghe
- Department of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - Christoph Cremer
- Kirchhoff Institut für Physik, University of Heidelberg, Heidelberg, Germany
| | - Mark B. Cannell
- Department of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - Christian Soeller
- Department of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
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