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Giuraniuc CV, Parkin C, Almeida MC, Fricker M, Shadmani P, Nye S, Wehmeier S, Chawla S, Bedekovic T, Lehtovirta-Morley L, Richards DM, Gow NA, Brand AC. Dynamic calcium-mediated stress response and recovery signatures in the fungal pathogen, Candida albicans. mBio 2023; 14:e0115723. [PMID: 37750683 PMCID: PMC10653887 DOI: 10.1128/mbio.01157-23] [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: 05/09/2023] [Accepted: 08/07/2023] [Indexed: 09/27/2023] Open
Abstract
IMPORTANCE Intracellular calcium signaling plays an important role in the resistance and adaptation to stresses encountered by fungal pathogens within the host. This study reports the optimization of the GCaMP fluorescent calcium reporter for live-cell imaging of dynamic calcium responses in single cells of the pathogen, Candida albicans, for the first time. Exposure to membrane, osmotic or oxidative stress generated both specific changes in single cell intracellular calcium spiking and longer calcium transients across the population. Repeated treatments showed that calcium dynamics become unaffected by some stresses but not others, consistent with known cell adaptation mechanisms. By expressing GCaMP in mutant strains and tracking the viability of individual cells over time, the relative contributions of key signaling pathways to calcium flux, stress adaptation, and cell death were demonstrated. This reporter, therefore, permits the study of calcium dynamics, homeostasis, and signaling in C. albicans at a previously unattainable level of detail.
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Affiliation(s)
- C. V. Giuraniuc
- School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Aberdeen, United Kingdom
| | - C. Parkin
- MRC Centre for Medical Mycology at the University of Exeter, Exeter, United Kingdom
| | - M. C. Almeida
- School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Aberdeen, United Kingdom
| | - M. Fricker
- School of Plant Sciences, University of Oxford, Oxford, United Kingdom
| | - P. Shadmani
- Living Systems Institute, University of Exeter, Exeter, United Kingdom
| | - S. Nye
- Living Systems Institute, University of Exeter, Exeter, United Kingdom
| | - S. Wehmeier
- School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Aberdeen, United Kingdom
| | - S. Chawla
- School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Aberdeen, United Kingdom
| | - T. Bedekovic
- School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Aberdeen, United Kingdom
- MRC Centre for Medical Mycology at the University of Exeter, Exeter, United Kingdom
| | - L. Lehtovirta-Morley
- School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Aberdeen, United Kingdom
| | - D. M. Richards
- Living Systems Institute, University of Exeter, Exeter, United Kingdom
- Department of Physics and Astronomy, University of Exeter, Exeter, United Kingdom
| | - N. A. Gow
- School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Aberdeen, United Kingdom
- MRC Centre for Medical Mycology at the University of Exeter, Exeter, United Kingdom
| | - A. C. Brand
- School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Aberdeen, United Kingdom
- MRC Centre for Medical Mycology at the University of Exeter, Exeter, United Kingdom
- Living Systems Institute, University of Exeter, Exeter, United Kingdom
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Faber BG, Bredbenner TL, Baird D, Gregory J, Saunders F, Giuraniuc CV, Aspden RM, Lane NE, Orwoll E, Tobias JH. Subregional statistical shape modelling identifies lesser trochanter size as a possible risk factor for radiographic hip osteoarthritis, a cross-sectional analysis from the Osteoporotic Fractures in Men Study. Osteoarthritis Cartilage 2020; 28:1071-1078. [PMID: 32387760 PMCID: PMC7387228 DOI: 10.1016/j.joca.2020.04.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 03/17/2020] [Accepted: 04/27/2020] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Statistical shape modelling (SSM) of hip dual-energy X-ray absorptiometry (DXA) scans has identified relationships between hip shape and radiographic hip OA (rHOA). We aimed to further elucidate shape characteristics related to rHOA by focusing on subregions identified from whole-hip shape models. METHOD SSM was applied to hip DXAs obtained in the Osteoporotic Fractures in Men Study. Whole-hip shape modes (HSMs) associated with rHOA were combined to form a composite at-risk-shape. Subsequently, subregional HSMs (cam-type and lesser trochanter modes) were built, and associations with rHOA were examined by logistic regression. Subregional HSMs were further characterised, by examining associations with 3D-HSMs derived from concurrent hip CT scans. RESULTS 4,098 participants were identified with hip DXAs and radiographs. Composite shapes from whole-hip HSMs revealed that lesser trochanter size and cam-type femoral head are related to rHOA. From sub-regional models, lesser trochanter mode (LTM)1 [OR 0.74; 95%CI 0.63.0.87] and cam-type mode (CTM)3 [OR 1.27; 1.13.1.42] were associated with rHOA, associations being similar to those for whole hip HSMs. 515 MrOS participants had hip DXAs and 3D-HSMs derived from hip CT scans. LTM1 was associated with 3D-HSMs that also represented a larger lesser trochanter [3D-HSM7 (beta (β)-0.23;-0.33,-0.14) and 3D-HSM9 (β0.36; 0.27.0.45)], and CTM3 with 3D-HSMs describing cam morphology [3D-HSM3 (β-0.16;-0.25,-0.07) and 3D-HSM6 (β 0.19; 0.10.0.28)]. CONCLUSION Subregional SSM of hip DXA scans suggested larger lesser trochanter and cam morphology underlie associations between overall hip shape and rHOA. 3D hip modelling suggests our subregional SSMs represent true anatomical variations in hip shape, warranting further investigation.
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Affiliation(s)
- B G Faber
- Medical Research Council Clinical Research Fellow, Musculoskeletal Research Unit, University of Bristol, Bristol, UK.
| | - T L Bredbenner
- Mechanical and Aerospace Engineering, University of Colorado Colorado Springs, Colorado, USA
| | - D Baird
- Integrative Epidemiology Unit, University of Bristol, Bristol, UK
| | - J Gregory
- Centre for Arthritis and Musculoskeletal Health, University of Aberdeen, Aberdeen, UK
| | - F Saunders
- Centre for Arthritis and Musculoskeletal Health, University of Aberdeen, Aberdeen, UK
| | - C V Giuraniuc
- Centre for Arthritis and Musculoskeletal Health, University of Aberdeen, Aberdeen, UK
| | - R M Aspden
- Centre for Arthritis and Musculoskeletal Health, University of Aberdeen, Aberdeen, UK
| | - N E Lane
- Center for Musculoskeletal Health, U.C. Davis School of Medicine, Sacramento, CA 95817, USA
| | - E Orwoll
- Bone and Mineral Unit, Oregon Health and Sciences University, Portland, OR, USA
| | - J H Tobias
- Musculoskeletal Research Unit, University of Bristol, Bristol, UK
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Blossey R, Giuraniuc CV. Mean-field versus stochastic models for transcriptional regulation. Phys Rev E Stat Nonlin Soft Matter Phys 2008; 78:031909. [PMID: 18851067 DOI: 10.1103/physreve.78.031909] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2008] [Revised: 08/16/2008] [Indexed: 05/26/2023]
Abstract
We introduce a minimal model description for the dynamics of transcriptional regulatory networks. It is studied within a mean-field approximation, i.e., by deterministic ODE's representing the reaction kinetics, and by stochastic simulations employing the Gillespie algorithm. We elucidate the different results that both approaches can deliver, depending on the network under study, and in particular depending on the level of detail retained in the respective description. Two examples are addressed in detail: The repressilator, a transcriptional clock based on a three-gene network realized experimentally in E. coli, and a bistable two-gene circuit under external driving, a transcriptional network motif recently proposed to play a role in cellular development.
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Affiliation(s)
- R Blossey
- Biological Nanosystems, Interdisciplinary Research Institute, Lille University of Science and Technology, USR 3078 CNRS, Parc Scientifique de la Haute Borne, 50, Avenue Halley, F-59658 Villeneuve d'Ascq, France
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Giuraniuc CV, Hatchett JPL, Indekeu JO, Leone M, Pérez Castillo I, Van Schaeybroeck B, Vanderzande C. Criticality on networks with topology-dependent interactions. Phys Rev E Stat Nonlin Soft Matter Phys 2006; 74:036108. [PMID: 17025709 DOI: 10.1103/physreve.74.036108] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2006] [Indexed: 05/12/2023]
Abstract
Weighted scale-free networks with topology-dependent interactions are studied. It is shown that the possible universality classes of critical behavior, which are known to depend on topology, can also be explored by tuning the form of the interactions at fixed topology. For a model of opinion formation, simple mean field and scaling arguments show that a mapping gamma'=(gamma-mu)(1-mu) describes how a shift of the standard exponent gamma of the degree distribution can absorb the effect of degree-dependent pair interactions J(ij) proportional to (k(i)k(j))(-mu), where k(i) stands for the degree of vertex i. This prediction is verified by extensive numerical investigations using the cavity method and Monte Carlo simulations. The critical temperature of the model is obtained through the Bethe-Peierls approximation and with the replica technique. The mapping can be extended to nonequilibrium models such as those describing the spreading of a disease on a network.
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Affiliation(s)
- C V Giuraniuc
- Laboratorium voor Vaste-Stoffysica en Magnetisme, Katholieke Universiteit Leuven, B-3001 Leuven, Belgium
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Giuraniuc CV, Hatchett JPL, Indekeu JO, Leone M, Pérez Castillo I, Van Schaeybroeck B, Vanderzande C. Trading interactions for topology in scale-free networks. Phys Rev Lett 2005; 95:098701. [PMID: 16197261 DOI: 10.1103/physrevlett.95.098701] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2004] [Indexed: 05/04/2023]
Abstract
Scale-free networks with topology-dependent interactions are studied. It is shown that the universality classes of critical behavior, which conventionally depend only on topology, can also be explored by tuning the interactions. A mapping, gamma'=(gamma-mu)/(1-mu), describes how a shift of the standard exponent gamma of the degree distribution P(q) can absorb the effect of degree-dependent pair interactions J(ij)proportional to(q(i)q(j))(-mu). The replica technique, cavity method, and Monte Carlo simulation support the physical picture suggested by Landau theory for the critical exponents and by the Bethe-Peierls approximation for the critical temperature. The equivalence of topology and interaction holds for equilibrium and nonequilibrium systems, and is illustrated with interdisciplinary applications.
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Affiliation(s)
- C V Giuraniuc
- Laboratorium voor Vaste-Stoffysica en Magnetisme, Katholieke Universiteit Leuven, 3001 Leuven, Belgium
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