1
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Plavskii VY, Sobchuk AN, Mikulich AV, Dudinova ON, Plavskaya LG, Tretyakova AI, Nahorny RK, Ananich TS, Svechko AD, Yakimchuk SV, Leusenka IA. Identification by methods of steady-state and kinetic spectrofluorimetry of endogenous porphyrins and flavins sensitizing the formation of reactive oxygen species in cancer cells. Photochem Photobiol 2024; 100:1310-1327. [PMID: 38258972 DOI: 10.1111/php.13911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 12/20/2023] [Accepted: 01/09/2024] [Indexed: 01/24/2024]
Abstract
The question about acceptor molecules of optical radiation that determine the effects of photobiomodulation in relation to various types of cells still remains the focus of attention of researchers. This issue is most relevant for cancer cells, since, depending on the parameters of optical radiation, light can either stimulate their growth or inhibit them and lead to death. This study shows that endogenous porphyrins, which have sensitizing properties, may play an important role in the implementation of the effects of photobiomodulation, along with flavins. For the first time, using steady-state and kinetic spectrofluorimetry, free-base porphyrins and their zinc complexes were discovered and identified in living human cervical epithelial carcinoma (HeLa) cells, as well as in their extracts. It has been shown that reliable detection of porphyrin fluorescence in cells is hampered by the intense fluorescence of flavins due to their high concentration (micromolar range) and higher (compared to tetrapyrroles) fluorescence quantum yield. Optimization of the spectral range of excitation and the use of extractants that provide multiple quenching of the flavin component while increasing the emission efficiency of tetrapyrroles makes it possible to weaken the contribution of the flavin component to the recorded fluorescence spectra.
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Affiliation(s)
- Vitaly Yu Plavskii
- State Scientific Institution "B.I. Stepanov Institute of Physics of the National Academy of Sciences of Belarus", Minsk, Belarus
| | - Andrei N Sobchuk
- State Scientific Institution "B.I. Stepanov Institute of Physics of the National Academy of Sciences of Belarus", Minsk, Belarus
| | - Aliaksandr V Mikulich
- State Scientific Institution "B.I. Stepanov Institute of Physics of the National Academy of Sciences of Belarus", Minsk, Belarus
| | - Olga N Dudinova
- State Scientific Institution "B.I. Stepanov Institute of Physics of the National Academy of Sciences of Belarus", Minsk, Belarus
| | - Ludmila G Plavskaya
- State Scientific Institution "B.I. Stepanov Institute of Physics of the National Academy of Sciences of Belarus", Minsk, Belarus
| | - Antonina I Tretyakova
- State Scientific Institution "B.I. Stepanov Institute of Physics of the National Academy of Sciences of Belarus", Minsk, Belarus
| | - Raman K Nahorny
- State Scientific Institution "B.I. Stepanov Institute of Physics of the National Academy of Sciences of Belarus", Minsk, Belarus
| | - Tatsiana S Ananich
- State Scientific Institution "B.I. Stepanov Institute of Physics of the National Academy of Sciences of Belarus", Minsk, Belarus
| | - Alexei D Svechko
- State Scientific Institution "B.I. Stepanov Institute of Physics of the National Academy of Sciences of Belarus", Minsk, Belarus
| | - Sergey V Yakimchuk
- State Scientific Institution "B.I. Stepanov Institute of Physics of the National Academy of Sciences of Belarus", Minsk, Belarus
| | - Ihar A Leusenka
- State Scientific Institution "B.I. Stepanov Institute of Physics of the National Academy of Sciences of Belarus", Minsk, Belarus
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2
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Hore PJ. Spin chemistry in living systems. Natl Sci Rev 2024; 11:nwae126. [PMID: 39144744 PMCID: PMC11321246 DOI: 10.1093/nsr/nwae126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 03/26/2024] [Accepted: 03/26/2024] [Indexed: 08/16/2024] Open
Affiliation(s)
- P J Hore
- Department of Chemistry, Oxford University, UK
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3
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Zakrzewski J, Liberka M, Wang J, Chorazy S, Ohkoshi SI. Optical Phenomena in Molecule-Based Magnetic Materials. Chem Rev 2024; 124:5930-6050. [PMID: 38687182 PMCID: PMC11082909 DOI: 10.1021/acs.chemrev.3c00840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
Since the last century, we have witnessed the development of molecular magnetism which deals with magnetic materials based on molecular species, i.e., organic radicals and metal complexes. Among them, the broadest attention was devoted to molecule-based ferro-/ferrimagnets, spin transition materials, including those exploring electron transfer, molecular nanomagnets, such as single-molecule magnets (SMMs), molecular qubits, and stimuli-responsive magnetic materials. Their physical properties open the application horizons in sensors, data storage, spintronics, and quantum computation. It was found that various optical phenomena, such as thermochromism, photoswitching of magnetic and optical characteristics, luminescence, nonlinear optical and chiroptical effects, as well as optical responsivity to external stimuli, can be implemented into molecule-based magnetic materials. Moreover, the fruitful interactions of these optical effects with magnetism in molecule-based materials can provide new physical cross-effects and multifunctionality, enriching the applications in optical, electronic, and magnetic devices. This Review aims to show the scope of optical phenomena generated in molecule-based magnetic materials, including the recent advances in such areas as high-temperature photomagnetism, optical thermometry utilizing SMMs, optical addressability of molecular qubits, magneto-chiral dichroism, and opto-magneto-electric multifunctionality. These findings are discussed in the context of the types of optical phenomena accessible for various classes of molecule-based magnetic materials.
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Affiliation(s)
- Jakub
J. Zakrzewski
- Faculty
of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Krakow, Poland
- Doctoral
School of Exact and Natural Sciences, Jagiellonian
University, Lojasiewicza
11, 30-348 Krakow, Poland
| | - Michal Liberka
- Faculty
of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Krakow, Poland
- Doctoral
School of Exact and Natural Sciences, Jagiellonian
University, Lojasiewicza
11, 30-348 Krakow, Poland
| | - Junhao Wang
- Department
of Materials Science, Faculty of Pure and Applied Science, University of Tsukuba, 1-1-1 Tonnodai, Tsukuba, Ibaraki 305-8573, Japan
| | - Szymon Chorazy
- Faculty
of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Krakow, Poland
| | - Shin-ichi Ohkoshi
- Department
of Chemistry, School of Science, The University
of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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4
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Liu L, Huang B, Lu Y, Zhao Y, Tang X, Shi Y. Interactions between electromagnetic radiation and biological systems. iScience 2024; 27:109201. [PMID: 38433903 PMCID: PMC10906530 DOI: 10.1016/j.isci.2024.109201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/05/2024] Open
Abstract
Even though the bioeffects of electromagnetic radiation (EMR) have been extensively investigated during the past several decades, our understandings of the bioeffects of EMR and the mechanisms of the interactions between the biological systems and the EMRs are still far from satisfactory. In this article, we introduce and summarize the consensus, controversy, limitations, and unsolved issues. The published works have investigated the EMR effects on different biological systems including humans, animals, cells, and biochemical reactions. Alternative methodologies also include dielectric spectroscopy, detection of bioelectromagnetic emissions, and theoretical predictions. In many studies, the thermal effects of the EMR are not properly controlled or considered. The frequency of the EMR investigated is limited to the commonly used bands, particularly the frequencies of the power line and the wireless communications; far fewer studies were performed for other EMR frequencies. In addition, the bioeffects of the complex EM environment were rarely discussed. In summary, our understanding of the bioeffects of the EMR is quite restrictive and further investigations are needed to answer the unsolved questions.
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Affiliation(s)
- Lingyu Liu
- Beijing Advanced Innovation Center for Structural Biology & Frontier Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Bing Huang
- Brain Function and Disease Laboratory, Department of Pharmacology, Shantou University Medical College, 22 Xin-Ling Road, Shantou 515041, China
| | - Yingxian Lu
- Westlake Laboratory of Life Sciences and Biomedicine, Xihu District, Hangzhou 310024, Zhejiang Province, China
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University; Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
| | - Yanyu Zhao
- Westlake Laboratory of Life Sciences and Biomedicine, Xihu District, Hangzhou 310024, Zhejiang Province, China
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University; Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
| | - Xiaping Tang
- Westlake Laboratory of Life Sciences and Biomedicine, Xihu District, Hangzhou 310024, Zhejiang Province, China
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University; Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
| | - Yigong Shi
- Beijing Advanced Innovation Center for Structural Biology & Frontier Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Westlake Laboratory of Life Sciences and Biomedicine, Xihu District, Hangzhou 310024, Zhejiang Province, China
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University; Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
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5
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Smith HE, Mackenzie AM, Seddon C, Mould R, Kalampouka I, Malakar P, Needham SR, Beis K, Bell JD, Nunn A, Botchway SW. The use of NADH anisotropy to investigate mitochondrial cristae alignment. Sci Rep 2024; 14:5980. [PMID: 38472304 PMCID: PMC10933486 DOI: 10.1038/s41598-024-55780-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 02/26/2024] [Indexed: 03/14/2024] Open
Abstract
Life may be expressed as the flow of electrons, protons, and other ions, resulting in large potential difference. It is also highly photo-sensitive, as a large proportion of the redox capable molecules it relies on are chromophoric. It is thus suggestive that a key organelle in eukaryotes, the mitochondrion, constantly adapt their morphology as part of the homeostatic process. Studying unstained in vivo nano-scale structure in live cells is technically very challenging. One option is to study a central electron carrier in metabolism, reduced nicotinamide adenine dinucleotide (NADH), which is fluorescent and mostly located within mitochondria. Using one and two-photon absorption (340-360 nm and 730 nm, respectively), fluorescence lifetime imaging and anisotropy spectroscopy of NADH in solution and in live cells, we show that mitochondria do indeed appear to be aligned and exhibit high anisotropy (asymmetric directionality). Aqueous solution of NADH showed an anisotropy of ~ 0.20 compared to fluorescein or coumarin of < 0.1 and 0.04 in water respectively and as expected for small organic molecules. The anisotropy of NADH also increased further to 0.30 in the presence of proteins and 0.42 in glycerol (restricted environment) following two-photon excitation, suggesting more ordered structures. Two-photon NADH fluorescence imaging of Michigan Cancer Foundation-7 (MCF7) also showed strong anisotropy of 0.25 to 0.45. NADH has a quantum yield of fluorescence of 2% compared to more than 40% for photoionisation (electron generation), when exposed to light at 360 nm and below. The consequence of such highly ordered and directional NADH patterns with respect to electron ejection upon ultra-violet (UV) excitation could be very informative-especially in relation to ascertaining the extent of quantum effects in biology, including electron and photonic cascade, communication and modulation of effects such as spin and tunnelling.
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Affiliation(s)
- Holly E Smith
- UKRI, STFC, Central Laser Facility, Rutherford Appleton Laboratory, Oxfordshire, OX11 0QX, UK
| | - Alasdair M Mackenzie
- UKRI, STFC, Central Laser Facility, Rutherford Appleton Laboratory, Oxfordshire, OX11 0QX, UK
| | - Chloe Seddon
- Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK
- Rutherford Appleton Laboratory, Research Complex at Harwell, Didcot, Oxfordshire, OX11 0FA, UK
| | - Rhys Mould
- School of Life Sciences, Research Centre for Optimal Health, University of Westminster, London, W1W 6UW, UK
| | - Ifi Kalampouka
- School of Life Sciences, Research Centre for Optimal Health, University of Westminster, London, W1W 6UW, UK
| | - Partha Malakar
- UKRI, STFC, Central Laser Facility, Rutherford Appleton Laboratory, Oxfordshire, OX11 0QX, UK
| | - Sarah R Needham
- UKRI, STFC, Central Laser Facility, Rutherford Appleton Laboratory, Oxfordshire, OX11 0QX, UK
| | - Konstantinos Beis
- Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK
- Rutherford Appleton Laboratory, Research Complex at Harwell, Didcot, Oxfordshire, OX11 0FA, UK
| | - Jimmy D Bell
- School of Life Sciences, Research Centre for Optimal Health, University of Westminster, London, W1W 6UW, UK
| | - Alistair Nunn
- School of Life Sciences, Research Centre for Optimal Health, University of Westminster, London, W1W 6UW, UK
| | - Stanley W Botchway
- UKRI, STFC, Central Laser Facility, Rutherford Appleton Laboratory, Oxfordshire, OX11 0QX, UK.
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6
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Aguida B, Babo J, Baouz S, Jourdan N, Procopio M, El-Esawi MA, Engle D, Mills S, Wenkel S, Huck A, Berg-Sørensen K, Kampranis SC, Link J, Ahmad M. 'Seeing' the electromagnetic spectrum: spotlight on the cryptochrome photocycle. FRONTIERS IN PLANT SCIENCE 2024; 15:1340304. [PMID: 38495372 PMCID: PMC10940379 DOI: 10.3389/fpls.2024.1340304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 01/12/2024] [Indexed: 03/19/2024]
Abstract
Cryptochromes are widely dispersed flavoprotein photoreceptors that regulate numerous developmental responses to light in plants, as well as to stress and entrainment of the circadian clock in animals and humans. All cryptochromes are closely related to an ancient family of light-absorbing flavoenzymes known as photolyases, which use light as an energy source for DNA repair but themselves have no light sensing role. Here we review the means by which plant cryptochromes acquired a light sensing function. This transition involved subtle changes within the flavin binding pocket which gave rise to a visual photocycle consisting of light-inducible and dark-reversible flavin redox state transitions. In this photocycle, light first triggers flavin reduction from an initial dark-adapted resting state (FADox). The reduced state is the biologically active or 'lit' state, correlating with biological activity. Subsequently, the photoreduced flavin reoxidises back to the dark adapted or 'resting' state. Because the rate of reoxidation determines the lifetime of the signaling state, it significantly modulates biological activity. As a consequence of this redox photocycle Crys respond to both the wavelength and the intensity of light, but are in addition regulated by factors such as temperature, oxygen concentration, and cellular metabolites that alter rates of flavin reoxidation even independently of light. Mechanistically, flavin reduction is correlated with conformational change in the protein, which is thought to mediate biological activity through interaction with biological signaling partners. In addition, a second, entirely independent signaling mechanism arises from the cryptochrome photocycle in the form of reactive oxygen species (ROS). These are synthesized during flavin reoxidation, are known mediators of biotic and abiotic stress responses, and have been linked to Cry biological activity in plants and animals. Additional special properties arising from the cryptochrome photocycle include responsivity to electromagnetic fields and their applications in optogenetics. Finally, innovations in methodology such as the use of Nitrogen Vacancy (NV) diamond centers to follow cryptochrome magnetic field sensitivity in vivo are discussed, as well as the potential for a whole new technology of 'magneto-genetics' for future applications in synthetic biology and medicine.
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Affiliation(s)
- Blanche Aguida
- Unite Mixed de Recherche (UMR) Centre Nationale de la Recherche Scientifique (CNRS) 8256 (B2A), Institut de Biologie Paris-Seine (IBPS), Sorbonne Université, Paris, France
| | - Jonathan Babo
- Unite Mixed de Recherche (UMR) Centre Nationale de la Recherche Scientifique (CNRS) 8256 (B2A), Institut de Biologie Paris-Seine (IBPS), Sorbonne Université, Paris, France
| | - Soria Baouz
- Unite Mixed de Recherche (UMR) Centre Nationale de la Recherche Scientifique (CNRS) 8256 (B2A), Institut de Biologie Paris-Seine (IBPS), Sorbonne Université, Paris, France
| | - Nathalie Jourdan
- Unite Mixed de Recherche (UMR) Centre Nationale de la Recherche Scientifique (CNRS) 8256 (B2A), Institut de Biologie Paris-Seine (IBPS), Sorbonne Université, Paris, France
| | - Maria Procopio
- Department of Biophysics, Faculty of Arts and Sciences, Johns Hopkins University, Baltimore, MD, United States
| | | | - Dorothy Engle
- Biology Department, Xavier University, Cincinnati, OH, United States
| | - Stephen Mills
- Chemistry Department, Xavier University, Cincinnati, OH, United States
| | - Stephan Wenkel
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Umeå, Sweden
| | - Alexander Huck
- DTU Physics, Technical University of Denmark, Kongens Lyngby, Denmark
| | | | - Sotirios C. Kampranis
- Biochemical Engineering Group, Plant Biochemistry Section, Department of Plant and Environment Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Justin Link
- Physics and Engineering Department, Cincinnati, OH, United States
| | - Margaret Ahmad
- Unite Mixed de Recherche (UMR) Centre Nationale de la Recherche Scientifique (CNRS) 8256 (B2A), Institut de Biologie Paris-Seine (IBPS), Sorbonne Université, Paris, France
- Biology Department, Xavier University, Cincinnati, OH, United States
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7
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Austvold CK, Keable SM, Procopio M, Usselman RJ. Quantitative measurements of reactive oxygen species partitioning in electron transfer flavoenzyme magnetic field sensing. Front Physiol 2024; 15:1348395. [PMID: 38370016 PMCID: PMC10869518 DOI: 10.3389/fphys.2024.1348395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Accepted: 01/16/2024] [Indexed: 02/20/2024] Open
Abstract
Biological magnetic field sensing that gives rise to physiological responses is of considerable importance in quantum biology. The radical pair mechanism (RPM) is a fundamental quantum process that can explain some of the observed biological magnetic effects. In magnetically sensitive radical pair (RP) reactions, coherent spin dynamics between singlet and triplet pairs are modulated by weak magnetic fields. The resulting singlet and triplet reaction products lead to distinct biological signaling channels and cellular outcomes. A prevalent RP in biology is between flavin semiquinone and superoxide (O2 •-) in the biological activation of molecular oxygen. This RP can result in a partitioning of reactive oxygen species (ROS) products to form either O2 •- or hydrogen peroxide (H2O2). Here, we examine magnetic sensing of recombinant human electron transfer flavoenzyme (ETF) reoxidation by selectively measuring O2 •- and H2O2 product distributions. ROS partitioning was observed between two static magnetic fields at 20 nT and 50 μT, with a 13% decrease in H2O2 singlet products and a 10% increase in O2 •- triplet products relative to 50 µT. RPM product yields were calculated for a realistic flavin/superoxide RP across the range of static magnetic fields, in agreement with experimental results. For a triplet born RP, the RPM also predicts about three times more O2 •- than H2O2, with experimental results exhibiting about four time more O2 •- produced by ETF. The method presented here illustrates the potential of a novel magnetic flavoprotein biological sensor that is directly linked to mitochondria bioenergetics and can be used as a target to study cell physiology.
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Affiliation(s)
- Chase K. Austvold
- Chemistry and Biochemistry, Montana State University, Bozeman, MT, United States
| | - Stephen M. Keable
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Maria Procopio
- Biophysics, Johns Hopkins University, Baltimore, MD, United States
| | - Robert J. Usselman
- Chemistry and Chemical Engineering, Florida Institute of Technology, Melbourne, FL, United States
- Computational Research At Florida Tech, Melbourne, FL, United States
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8
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Vecheck AM, McNamee CM, Reijo Pera R, Usselman RJ. Magnetic Field Intervention Enhances Cellular Migration Rates in Biological Scaffolds. Bioengineering (Basel) 2023; 11:9. [PMID: 38247887 PMCID: PMC10813414 DOI: 10.3390/bioengineering11010009] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 12/15/2023] [Accepted: 12/20/2023] [Indexed: 01/23/2024] Open
Abstract
The impact of magnetic fields on cellular function is diverse but can be described at least in part by the radical pair mechanism (RPM), where magnetic field intervention alters reactive oxygen species (ROS) populations and downstream cellular signaling. Here, cellular migration within three-dimensional scaffolds was monitored in an applied oscillating 1.4 MHz radiofrequency (RF) magnetic field with an amplitude of 10 µT and a static 50 µT magnetic field. Given that cellular bioenergetics can be altered based on applied RF magnetic fields, this study focused on a magnetic field configuration that increased cellular respiration. Results suggest that RF accelerated cell clustering and elongation after 1 day, with increased levels of clustering and cellular linkage after 7 days. Cell distribution analysis within the scaffolds revealed that the clustering rate during the first day was increased nearly five times in the RF environment. Electron microscopy provided additional topological information and verified the development of fibrous networks, with a cell-derived matrix (CDM) visualized after 7 days in samples maintained in RF. This work demonstrates time-dependent cellular migration that may be influenced by quantum biology (QB) processes and downstream oxidative signaling, enhancing cellular migration behavior.
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Affiliation(s)
- Amy M. Vecheck
- Department of Biomedical Engineering and Sciences, Florida Institute of Technology, Melbourne, FL 32901, USA
| | - Cameron M. McNamee
- Department of Mathematics, California Institute of Technology, Pasadena, CA 91125, USA
- McLaughlin Research Institute, Great Falls, MT 59405, USA
| | | | - Robert J. Usselman
- Department of Chemistry and Chemical Engineering, Florida Institute of Technology, Melbourne, FL 32901, USA
- Computational Research At Florida Tech (CRAFT), Florida Institute of Technology, Melbourne, FL 32901, USA
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9
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Franco-Obregón A. Harmonizing Magnetic Mitohormetic Regenerative Strategies: Developmental Implications of a Calcium-Mitochondrial Axis Invoked by Magnetic Field Exposure. Bioengineering (Basel) 2023; 10:1176. [PMID: 37892906 PMCID: PMC10604793 DOI: 10.3390/bioengineering10101176] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 10/05/2023] [Accepted: 10/08/2023] [Indexed: 10/29/2023] Open
Abstract
Mitohormesis is a process whereby mitochondrial stress responses, mediated by reactive oxygen species (ROS), act cumulatively to either instill survival adaptations (low ROS levels) or to produce cell damage (high ROS levels). The mitohormetic nature of extremely low-frequency electromagnetic field (ELF-EMF) exposure thus makes it susceptible to extraneous influences that also impinge on mitochondrial ROS production and contribute to the collective response. Consequently, magnetic stimulation paradigms are prone to experimental variability depending on diverse circumstances. The failure, or inability, to control for these factors has contributed to the existing discrepancies between published reports and in the interpretations made from the results generated therein. Confounding environmental factors include ambient magnetic fields, temperature, the mechanical environment, and the conventional use of aminoglycoside antibiotics. Biological factors include cell type and seeding density as well as the developmental, inflammatory, or senescence statuses of cells that depend on the prior handling of the experimental sample. Technological aspects include magnetic field directionality, uniformity, amplitude, and duration of exposure. All these factors will exhibit manifestations at the level of ROS production that will culminate as a unified cellular response in conjunction with magnetic exposure. Fortunately, many of these factors are under the control of the experimenter. This review will focus on delineating areas requiring technical and biological harmonization to assist in the designing of therapeutic strategies with more clearly defined and better predicted outcomes and to improve the mechanistic interpretation of the generated data, rather than on precise applications. This review will also explore the underlying mechanistic similarities between magnetic field exposure and other forms of biophysical stimuli, such as mechanical stimuli, that mutually induce elevations in intracellular calcium and ROS as a prerequisite for biological outcome. These forms of biophysical stimuli commonly invoke the activity of transient receptor potential cation channel classes, such as TRPC1.
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Affiliation(s)
- Alfredo Franco-Obregón
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore; ; Tel.: +65-6777-8427 or +65-6601-6143
- Institute of Health Technology and Innovation (iHealthtech), National University of Singapore, Singapore 117599, Singapore
- Biolonic Currents Electromagnetic Pulsing Systems Laboratory (BICEPS), National University of Singapore, Singapore 117599, Singapore
- NUS Centre for Cancer Research (N2CR), Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore
- Healthy Longevity Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117593, Singapore
- Nanomedicine Translational Research Programme, Centre for NanoMedicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117544, Singapore
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10
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Winkler R, Ciria M, Ahmad M, Plank H, Marcuello C. A Review of the Current State of Magnetic Force Microscopy to Unravel the Magnetic Properties of Nanomaterials Applied in Biological Systems and Future Directions for Quantum Technologies. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2585. [PMID: 37764614 PMCID: PMC10536909 DOI: 10.3390/nano13182585] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 09/13/2023] [Accepted: 09/15/2023] [Indexed: 09/29/2023]
Abstract
Magnetism plays a pivotal role in many biological systems. However, the intensity of the magnetic forces exerted between magnetic bodies is usually low, which demands the development of ultra-sensitivity tools for proper sensing. In this framework, magnetic force microscopy (MFM) offers excellent lateral resolution and the possibility of conducting single-molecule studies like other single-probe microscopy (SPM) techniques. This comprehensive review attempts to describe the paramount importance of magnetic forces for biological applications by highlighting MFM's main advantages but also intrinsic limitations. While the working principles are described in depth, the article also focuses on novel micro- and nanofabrication procedures for MFM tips, which enhance the magnetic response signal of tested biomaterials compared to commercial nanoprobes. This work also depicts some relevant examples where MFM can quantitatively assess the magnetic performance of nanomaterials involved in biological systems, including magnetotactic bacteria, cryptochrome flavoproteins, and magnetic nanoparticles that can interact with animal tissues. Additionally, the most promising perspectives in this field are highlighted to make the reader aware of upcoming challenges when aiming toward quantum technologies.
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Affiliation(s)
- Robert Winkler
- Christian Doppler Laboratory—DEFINE, Graz University of Technology, 8010 Graz, Austria; (R.W.); (H.P.)
| | - Miguel Ciria
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain;
- Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza, Spain
| | - Margaret Ahmad
- Photobiology Research Group, IBPS, UMR8256 CNRS, Sorbonne Université, 75005 Paris, France;
| | - Harald Plank
- Christian Doppler Laboratory—DEFINE, Graz University of Technology, 8010 Graz, Austria; (R.W.); (H.P.)
- Graz Centre for Electron Microscopy, 8010 Graz, Austria
- Institute of Electron Microscopy, Graz University of Technology, 8010 Graz, Austria
| | - Carlos Marcuello
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain;
- Laboratorio de Microscopias Avanzadas (LMA), Universidad de Zaragoza, 50018 Zaragoza, Spain
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11
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Zhang L, Malkemper EP. Cryptochromes in mammals: a magnetoreception misconception? Front Physiol 2023; 14:1250798. [PMID: 37670767 PMCID: PMC10475740 DOI: 10.3389/fphys.2023.1250798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 08/01/2023] [Indexed: 09/07/2023] Open
Abstract
Cryptochromes are flavoproteins related to photolyases that are widespread throughout the plant and animal kingdom. They govern blue light-dependent growth in plants, control circadian rhythms in a light-dependent manner in invertebrates, and play a central part in the circadian clock in vertebrates. In addition, cryptochromes might function as receptors that allow animals to sense the Earth's magnetic field. As cryptochromes are also present in mammals including humans, the possibility of a magnetosensitive protein is exciting. Here we attempt to provide a concise overview of cryptochromes in mammals. We briefly review their canonical role in the circadian rhythm from the molecular level to physiology, behaviour and diseases. We then discuss their disputed light sensitivity and proposed role in the magnetic sense in mammals, providing three mechanistic hypotheses. Specifically, mammalian cryptochromes could form light-induced radical pairs in particular cellular milieus, act as magnetoreceptors in darkness, or as secondary players in a magnetoreception signalling cascade. Future research can test these hypotheses to investigate if the role of mammalian cryptochromes extends beyond the circadian clock.
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Affiliation(s)
| | - E. Pascal Malkemper
- Max Planck Research Group Neurobiology of Magnetoreception, Max Planck Institute for Neurobiology of Behavior—caesar, Bonn, Germany
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12
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Chuchkova L, Bodenstedt S, Picazo-Frutos R, Eills J, Tretiak O, Hu Y, Barskiy DA, de Santis J, Tayler MCD, Budker D, Sheberstov KF. Magnetometer-Detected Nuclear Magnetic Resonance of Photochemically Hyperpolarized Molecules. J Phys Chem Lett 2023:6814-6822. [PMID: 37486855 DOI: 10.1021/acs.jpclett.3c01310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/26/2023]
Abstract
Photochemically induced dynamic nuclear polarization (photo-CIDNP) enables nuclear spin ordering by irradiating samples with light. Polarized spins are conventionally detected via high-field chemical-shift-resolved NMR (above 0.1 T). In this Letter, we demonstrate in situ low-field photo-CIDNP measurements using a magnetically shielded fast-field-cycling NMR setup detecting Larmor precession via atomic magnetometers. For solutions comprising mM concentrations of the photochemically polarized molecules, hyperpolarized 1H magnetization is detected by pulse-acquired NMR spectroscopy. The observed NMR line widths are about 5 times narrower than normally anticipated in high-field NMR and are systematically affected by light irradiation during the acquisition period, reflecting a reduction of the transverse relaxation time constant, T2*, on the order of 10%. Magnetometer-detected photo-CIDNP spectroscopy enables straightforward observation of spin-chemistry processes in the ambient field range from a few nT to tens of mT. Potential applications of this measuring modality are discussed.
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Affiliation(s)
- Liubov Chuchkova
- Institut für Physik, Johannes Gutenberg Universität-Mainz, 55128 Mainz, Germany
- Helmholtz-Institut Mainz, GSI Helmholtzzentrum für Schwerionenforschung, 55128 Mainz, Germany
| | - Sven Bodenstedt
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
| | - Román Picazo-Frutos
- Institut für Physik, Johannes Gutenberg Universität-Mainz, 55128 Mainz, Germany
- Helmholtz-Institut Mainz, GSI Helmholtzzentrum für Schwerionenforschung, 55128 Mainz, Germany
| | - James Eills
- Institute for Bioengineering of Catalonia, 08028 Barcelona, Spain
| | - Oleg Tretiak
- Institut für Physik, Johannes Gutenberg Universität-Mainz, 55128 Mainz, Germany
- Helmholtz-Institut Mainz, GSI Helmholtzzentrum für Schwerionenforschung, 55128 Mainz, Germany
| | - Yinan Hu
- Institut für Physik, Johannes Gutenberg Universität-Mainz, 55128 Mainz, Germany
- Helmholtz-Institut Mainz, GSI Helmholtzzentrum für Schwerionenforschung, 55128 Mainz, Germany
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Danila A Barskiy
- Institut für Physik, Johannes Gutenberg Universität-Mainz, 55128 Mainz, Germany
- Helmholtz-Institut Mainz, GSI Helmholtzzentrum für Schwerionenforschung, 55128 Mainz, Germany
| | - Jacopo de Santis
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
| | - Michael C D Tayler
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
| | - Dmitry Budker
- Institut für Physik, Johannes Gutenberg Universität-Mainz, 55128 Mainz, Germany
- Helmholtz-Institut Mainz, GSI Helmholtzzentrum für Schwerionenforschung, 55128 Mainz, Germany
- Department of Physics, University of California, Berkeley, California 94720-7300, United States
| | - Kirill F Sheberstov
- Institut für Physik, Johannes Gutenberg Universität-Mainz, 55128 Mainz, Germany
- Helmholtz-Institut Mainz, GSI Helmholtzzentrum für Schwerionenforschung, 55128 Mainz, Germany
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13
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Uzhytchak M, Smolková B, Frtús A, Stupakov A, Lunova M, Scollo F, Hof M, Jurkiewicz P, Sullivan GJ, Dejneka A, Lunov O. Sensitivity of endogenous autofluorescence in HeLa cells to the application of external magnetic fields. Sci Rep 2023; 13:10818. [PMID: 37402779 DOI: 10.1038/s41598-023-38015-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 06/30/2023] [Indexed: 07/06/2023] Open
Abstract
Dramatically increased levels of electromagnetic radiation in the environment have raised concerns over the potential health hazards of electromagnetic fields. Various biological effects of magnetic fields have been proposed. Despite decades of intensive research, the molecular mechanisms procuring cellular responses remain largely unknown. The current literature is conflicting with regards to evidence that magnetic fields affect functionality directly at the cellular level. Therefore, a search for potential direct cellular effects of magnetic fields represents a cornerstone that may propose an explanation for potential health hazards associated with magnetic fields. It has been proposed that autofluorescence of HeLa cells is magnetic field sensitive, relying on single-cell imaging kinetic measurements. Here, we investigate the magnetic field sensitivity of an endogenous autofluorescence in HeLa cells. Under the experimental conditions used, magnetic field sensitivity of an endogenous autofluorescence was not observed in HeLa cells. We present a number of arguments indicating why this is the case in the analysis of magnetic field effects based on the imaging of cellular autofluorescence decay. Our work indicates that new methods are required to elucidate the effects of magnetic fields at the cellular level.
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Affiliation(s)
- Mariia Uzhytchak
- Department of Optical and Biophysical Systems, Institute of Physics of the Czech Academy of Sciences, Prague, 18221, Czech Republic
| | - Barbora Smolková
- Department of Optical and Biophysical Systems, Institute of Physics of the Czech Academy of Sciences, Prague, 18221, Czech Republic
| | - Adam Frtús
- Department of Optical and Biophysical Systems, Institute of Physics of the Czech Academy of Sciences, Prague, 18221, Czech Republic
| | - Alexandr Stupakov
- Department of Optical and Biophysical Systems, Institute of Physics of the Czech Academy of Sciences, Prague, 18221, Czech Republic
| | - Mariia Lunova
- Department of Optical and Biophysical Systems, Institute of Physics of the Czech Academy of Sciences, Prague, 18221, Czech Republic
- Institute for Clinical and Experimental Medicine (IKEM), Prague, 14021, Czech Republic
| | - Federica Scollo
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Prague, 18223, Czech Republic
| | - Martin Hof
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Prague, 18223, Czech Republic
| | - Piotr Jurkiewicz
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Prague, 18223, Czech Republic
| | - Gareth John Sullivan
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
- Department of Pediatric Research, Oslo University Hospital, Oslo, Norway
- Department of Immunology, Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Alexandr Dejneka
- Department of Optical and Biophysical Systems, Institute of Physics of the Czech Academy of Sciences, Prague, 18221, Czech Republic
| | - Oleg Lunov
- Department of Optical and Biophysical Systems, Institute of Physics of the Czech Academy of Sciences, Prague, 18221, Czech Republic.
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14
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Bradlaugh AA, Fedele G, Munro AL, Hansen CN, Hares JM, Patel S, Kyriacou CP, Jones AR, Rosato E, Baines RA. Essential elements of radical pair magnetosensitivity in Drosophila. Nature 2023; 615:111-116. [PMID: 36813962 PMCID: PMC9977682 DOI: 10.1038/s41586-023-05735-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 01/16/2023] [Indexed: 02/24/2023]
Abstract
Many animals use Earth's magnetic field (also known as the geomagnetic field) for navigation1. The favoured mechanism for magnetosensitivity involves a blue-light-activated electron-transfer reaction between flavin adenine dinucleotide (FAD) and a chain of tryptophan residues within the photoreceptor protein CRYPTOCHROME (CRY). The spin-state of the resultant radical pair, and therefore the concentration of CRY in its active state, is influenced by the geomagnetic field2. However, the canonical CRY-centric radical-pair mechanism does not explain many physiological and behavioural observations2-8. Here, using electrophysiology and behavioural analyses, we assay magnetic-field responses at the single-neuron and organismal levels. We show that the 52 C-terminal amino acid residues of Drosophila melanogaster CRY, lacking the canonical FAD-binding domain and tryptophan chain, are sufficient to facilitate magnetoreception. We also show that increasing intracellular FAD potentiates both blue-light-induced and magnetic-field-dependent effects on the activity mediated by the C terminus. High levels of FAD alone are sufficient to cause blue-light neuronal sensitivity and, notably, the potentiation of this response in the co-presence of a magnetic field. These results reveal the essential components of a primary magnetoreceptor in flies, providing strong evidence that non-canonical (that is, non-CRY-dependent) radical pairs can elicit magnetic-field responses in cells.
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Affiliation(s)
- Adam A Bradlaugh
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Giorgio Fedele
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
- Department of Biology, Ecology and Earth Sciences (DiBEST), University of Calabria, Rende, Italy
| | - Anna L Munro
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Celia Napier Hansen
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
| | - John M Hares
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
- Pelican Healthcare, Cardiff, UK
| | - Sanjai Patel
- Manchester Fly Facility, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | | | - Alex R Jones
- Biometrology, Chemical and Biological Sciences Department, National Physical Laboratory, Teddington, UK
| | - Ezio Rosato
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK.
| | - Richard A Baines
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK.
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15
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Yu X, Ji X, Fan Y, Yu B, Wang X, Feng C, Zhang L, Song C, Zhang X. Static Magnetic Fields Protect against Cisplatin-Induced Kidney Toxicity. Antioxidants (Basel) 2022; 12:73. [PMID: 36670933 PMCID: PMC9854588 DOI: 10.3390/antiox12010073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 12/26/2022] [Accepted: 12/27/2022] [Indexed: 01/01/2023] Open
Abstract
Cisplatin is one of the most widely used anti-cancer drugs that can effectively inhibit the growth of multiple types of cancer. However, its clinical application is limited by its severe side effects, especially kidney toxicity, caused by cisplatin-induced oxidative stress, inflammation and kidney cell apoptosis. Here, we found that moderate (a few hundred mT) quasi-uniform static magnetic fields (SMFs) could inhibit cisplatin-induced renal proximal tubular cell death, especially the vertically downward direction SMF. RNA-seq experiments demonstrate that SMFs induced differential gene expressions that are closely associated with oxidative stress, apoptosis, cytokine production, transmembrane transport and DNA repair. In vivo experiments show that SMFs can reduce cisplatin-induced kidney injury in cisplatin-administrated tumor-bearing mice by reducing oxidative stress, inflammation and cell apoptosis. Furthermore, high-dose cisplatin-induced acute nephrotoxicity can be effectively alleviated by SMF treatment of as little as one day, which significantly reduced the reactive oxygen species levels in kidneys and prolonged the mice's survival. Moreover, the concentration of cisplatin in the kidney was significantly attenuated in SMF-treated mice. Therefore, our study demonstrates the effects of moderate SMFs as a novel physical method to reduce oxidative stress, and revealed their future potential to be used against cisplatin-induced kidney toxicity in cancer treatment.
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Affiliation(s)
- Xin Yu
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China
- Science Island Branch of Graduate School, University of Science and Technology of China, Hefei 230036, China
| | - Xinmiao Ji
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China
| | - Yixiang Fan
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China
- Science Island Branch of Graduate School, University of Science and Technology of China, Hefei 230036, China
| | - Biao Yu
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China
| | - Xinyu Wang
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China
- Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, China
| | - Chuanlin Feng
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China
- Science Island Branch of Graduate School, University of Science and Technology of China, Hefei 230036, China
| | - Lei Zhang
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China
| | - Chao Song
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China
| | - Xin Zhang
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China
- Science Island Branch of Graduate School, University of Science and Technology of China, Hefei 230036, China
- Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, China
- International Magnetobiology Frontier Research Center, Science Island, Hefei 230036, China
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16
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Kyriacou CP, Rosato E. Genetic analysis of cryptochrome in insect magnetosensitivity. Front Physiol 2022; 13:928416. [PMID: 36035470 PMCID: PMC9399412 DOI: 10.3389/fphys.2022.928416] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 07/05/2022] [Indexed: 11/18/2022] Open
Abstract
The earth's magnetic field plays an important role in the spectacular migrations and navigational abilities of many higher animals, particularly birds. However, these organisms are not amenable to genetic analysis, unlike the model fruitfly, Drosophila melanogaster, which can respond to magnetic fields under laboratory conditions. We therefore review the field of insect magnetosensitivity focusing on the role of the Cryptochromes (CRYs) that were first identified in Arabidopsis and Drosophila as key molecular components of circadian photo-entrainment pathways. Physico-chemical studies suggest that photo-activation of flavin adenine dinucleotide (FAD) bound to CRY generates a FADo- Trpo+ radical pair as electrons skip along a chain of specific Trp residues and that the quantum spin chemistry of these radicals is sensitive to magnetic fields. The manipulation of CRY in several insect species has been performed using gene editing, replacement/rescue and knockdown methods. The effects of these various mutations on magnetosensitivity have revealed a number of surprises that are discussed in the light of recent developments from both in vivo and in vitro studies.
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Affiliation(s)
- Charalambos P. Kyriacou
- Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom
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17
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Zadeh-Haghighi H, Simon C. Magnetic field effects in biology from the perspective of the radical pair mechanism. J R Soc Interface 2022; 19:20220325. [PMID: 35919980 PMCID: PMC9346374 DOI: 10.1098/rsif.2022.0325] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 07/14/2022] [Indexed: 04/07/2023] Open
Abstract
Hundreds of studies have found that weak magnetic fields can significantly influence various biological systems. However, the underlying mechanisms behind these phenomena remain elusive. Remarkably, the magnetic energies implicated in these effects are much smaller than thermal energies. Here, we review these observations, and we suggest an explanation based on the radical pair mechanism, which involves the quantum dynamics of the electron and nuclear spins of transient radical molecules. While the radical pair mechanism has been studied in detail in the context of avian magnetoreception, the studies reviewed here show that magnetosensitivity is widespread throughout biology. We review magnetic field effects on various physiological functions, discussing static, hypomagnetic and oscillating magnetic fields, as well as isotope effects. We then review the radical pair mechanism as a potential unifying model for the described magnetic field effects, and we discuss plausible candidate molecules for the radical pairs. We review recent studies proposing that the radical pair mechanism provides explanations for isotope effects in xenon anaesthesia and lithium treatment of hyperactivity, magnetic field effects on the circadian clock, and hypomagnetic field effects on neurogenesis and microtubule assembly. We conclude by discussing future lines of investigation in this exciting new area of quantum biology.
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Affiliation(s)
- Hadi Zadeh-Haghighi
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada T2N 1N4
- Institute for Quantum Science and Technology, University of Calgary, Calgary, Alberta, Canada T2N 1N4
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada T2N 1N4
| | - Christoph Simon
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada T2N 1N4
- Institute for Quantum Science and Technology, University of Calgary, Calgary, Alberta, Canada T2N 1N4
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada T2N 1N4
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18
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Relationships Organize Information in Mind and Nature: Empirical Findings of Action–Reaction Relationships (R) in Cognitive and Material Complexity. SYSTEMS 2022. [DOI: 10.3390/systems10030071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Diverse phenomena such as feedback, interconnectedness, causality, network dynamics, and complexity are all born from Relationships. They are fundamentally important, as they are transdisciplinary and synonymous with connections, links, edges, and interconnections. The foundation of systems thinking and systems themselves consists of four universals, one of which is action–reaction Relationships. They are also foundational to the consilience of knowledge. This publication gives a formal description of and predictions of action–reaction Relationships (R) or “R-rule”. There are seven original empirical studies presented in this paper. For these seven studies, experiments for the subjects were created on software (unless otherwise noted). The experiments had the subjects complete a task and/or answer a question. The samples are generalizable to a normal distribution of the US population and they vary for each study (ranging from N = 407 to N = 34,398). With high statistical significance the studies support the predictions made by DSRP Theory regarding action–reaction Relationships including its universality as an observable phenomenon in both nature (ontological complexity) and mind (cognitive complexity); mutual dependencies on other universals (i.e., Distinctions, Systems, and Perspectives); role in structural predictions; internal structures and dynamics; efficacy as a metacognitive skill. In conclusion, these data suggest the observable and empirical existence, parallelism (between cognitive and ontological complexity), universality, and efficacy of action–reaction Relationships (R).
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Abstract
The potential therapeutic uses of electromagnetic fields (EMF), part of the nonionizing radiation spectrum, increase with time. Among them, those considering the potential antitumor effects exerted by the Magnetic Fields (MFs), part of the EMF entity, have gained more and more interest. A recent review on this subject reports the MFs' effect on apoptosis of tumor cells as one of the most important breakthroughs. Apoptosis is considered a key mechanism regulating the genetic stability of cells and as such is considered of fundamental importance in cancer initiation and development. According to an atomic/sub-atomic analysis, based on quantum physics, of the complexity of biological life and the role played by oxygen and its radicals in cancer biology, a possible biophysical mechanism is described. The mechanism considers the influence of MFs on apoptosis through an effect on electron spin that is able to increase reactive oxygen species (ROS) concentration. Impacting on the delicate balance between ROS production and ROS elimination in tumor cells is considered a promising cancer therapy, affecting different biological processes, such as apoptosis and metastasis. An analysis in the literature, which allows correlation between MFs exposure characteristics and their influence on apoptosis and ROS concentration, supports the validity of the mechanism.
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Affiliation(s)
- Santi Tofani
- Department of Medical Physics, Ivrea Hospital - ASL Torino Nord-Ovest TO4, Ivrea Torino, Italy.,Department of Public Health Science, School of Medicine, University of Turin, Ivrea Torino, Italy
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Perspectives Organize Information in Mind and Nature: Empirical Findings of Point-View Perspective (P) in Cognitive and Material Complexity. SYSTEMS 2022. [DOI: 10.3390/systems10030052] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The importance of perspective-taking crosses disciplines and is foundational to diverse phenomena such as point-of-view, scale, mindset, theory of mind, opinion, belief, empathy, compassion, analysis, and problem solving, etc. This publication gives predictions for and a formal description of point-view Perspectives (P) or the “P-rule”. This makes the P-rule foundational to systems, systems thinking and the consilience of knowledge. It is one of four universals of the organization of information as a whole. This paper presents nine empirical studies in which subjects were asked to complete a task and/or answer a question. The samples vary for each study (ranging from N = 407 to N = 34,398) and are generalizable to a normal distribution of the US population. As was evident in Cabrera, “These studies support—with high statistical significance—the predictions made by DSRP Theory (Distinctions, Systems Relationships, Perspectives) point-view Perspectives including its: universality as an observable phenomenon in both mind (cognitive complexity) and nature (material complexity) (i.e., parallelism); internal structures and dynamics; mutual dependencies on other universals (i.e., Distinctions, Systems, and Relationships); role in structural predictions; and, efficacy as a metacognitive skill”. These data suggest that point-view Perspectives (P) observably and empirically exist, and that universality, efficacy, and parallelism (between cognitive and material complexity) exist as well. The impact of this paper is that it provides empirical evidence for the phenomena of point-view perspective taking (“P-rule”) as a universal pattern/structure of systems thinking, a field in which scholarly debate is often based on invalidated opinioned frameworks; this sets the stage for theory building in the field.
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Systems Organize Information in Mind and Nature: Empirical Findings of Part-Whole Systems (S) in Cognitive and Material Complexity. SYSTEMS 2022. [DOI: 10.3390/systems10020044] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Part-whole Systems (S) structure is foundational to a diverse array of phenomena such as belonging and containment, networks, statistics, reductionism, holism, etc. and is extremely similar if not synonymous with sets, sorts, groups, combinations and combinatorics, clusters, etc. In Cabrera (1998), part-whole Systems (S) or “S-rule” is established as one of four universals for the organization of information and thus is foundational to systems and systems thinking as well as the consilience of knowledge. In this paper, seven empirical studies are presented in which (unless otherwise noted) subjects completed a task. Ranging from n = 407 to n = 34,398, the sample sizes vary for each study but are generalizeable to a normal distribution of the US population. With high statistical significance, the results of these studies support the predictions made by DSRP Theory regarding part-whole Systems (a.k.a., “S-rule”) including: the universality of S-rule as an observable phenomenon in both mind (cognitive complexity) and nature (ontological complexity) (i.e., parallelism); the internal structures and dynamics of S-rule; S-rule’s mutual dependencies on other universals of DSRP (Distinctions, Systems, Relationships, and Perspectives (i.e., Distinctions, Relationships, and Perspectives); the role S-rule plays in making structural predictions; and, S-rule’s efficacy as a metacognitive skill. In conclusion, these data suggest the observable and empirical existence, universality, efficacy, and parallelism (between cognitive and ontological complexity) of part-whole Systems (S).
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Distinctions Organize Information in Mind and Nature: Empirical Findings of Identity–Other Distinctions (D) in Cognitive and Material Complexity. SYSTEMS 2022. [DOI: 10.3390/systems10020041] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The transdisciplinary importance of distinctions is well-established as foundational to such diverse phenomena as recognition, identification, individual and social identity, marginalization, externalities, boundaries, concept formation, etc., and synonymous general ideas, such as thingness, concepts, nodes, objects, etc. Cabrera provides a formal description of and predictions for identity–other distinctions (D) or “D-rule” as one of four universals for the organization of information that is foundational to systems and systems thinking, as well as the consilience of knowledge. This paper presents seven empirical studies in which (unless otherwise noted) software was used to create an experiment for subjects to complete a task and/or answer a question. The samples varied for each study (ranging from N = 407 to N = 34,398) and were generalizable to a normal distribution of the US population. These studies support—with high statistical significance—the predictions made by DSRP theory regarding identity–other distinctions including its: universality as an observable phenomenon in both mind (cognitive complexity) and nature (ontological complexity) (i.e., parallelism); internal structures and dynamics; mutual dependencies on other universals (i.e., relationships, systems, and perspectives); role in structural predictions; and efficacy as a metacognitive skill. In conclusion, these data suggest the observable and empirical existence, universality, efficacy, and parallelism (between cognitive and ontological complexity) of identity–other distinctions (D).
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The “Fish Tank” Experiments: Metacognitive Awareness of Distinctions, Systems, Relationships, and Perspectives (DSRP) Significantly Increases Cognitive Complexity. SYSTEMS 2022. [DOI: 10.3390/systems10020029] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
In the field of systems thinking, there are far too many opinioned frameworks and far too few empirical studies. This could be described as a “gap” in the research but it is more like a dearth in the research. More theory and empirical validation of theory are needed if the field and the phenomenon of systems thinking holds promise and not just popularity. This validation comes in the form of both basic (existential) and applied (efficacy) research studies. This article presents efficacy data for a set of empirical studies of DSRP Theory. According to Cabrera, Cabrera, and Midgley, DSRP Theory has equal or more empirical evidence supporting it than any existing systems theories (including frameworks, which are not theories). Four separate studies show highly statistically relevant findings for the effect of a short (less than one minute) treatment of D, S, R, and P. Subjects’ cognitive complexity and the systemic nature of their thinking increased in all four studies. These findings indicate that even a short treatment in DSRP is effective in increasing systems thinking skills. Based on these results, a longer, more in-depth treatment—such as a one hour or semester long training, such is the norm—would therefore likely garner transformative results and efficacy.
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Abstract
DSRP Theory is now over 25 years old with more empirical evidence supporting it than any other systems thinking framework. Yet, it is often misunderstood and described in ways that are inaccurate. DSRP Theory describes four patterns and their underlying elements—identity (i) and other (o) for Distinctions (D), part (p) and whole (w) for Systems (S), action (a) and reaction (r) for Relationships (R), and point (ρ) and view (v) for Perspectives (P)—that are universal in both cognitive complexity (mind) and material complexity (nature). DSRP Theory provides a basis for systems thinking or cognitive complexity as well as material complexity (systems science). This paper, as a relatively short primer on the theory, provides clarity to those wanting to understand DSRP and its implications.
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Static Magnetic Fields Reduce Oxidative Stress to Improve Wound Healing and Alleviate Diabetic Complications. Cells 2022; 11:cells11030443. [PMID: 35159252 PMCID: PMC8834397 DOI: 10.3390/cells11030443] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 01/22/2022] [Accepted: 01/24/2022] [Indexed: 12/24/2022] Open
Abstract
Although some studies have shown that some static magnetic fields (SMFs) can promote wound healing in diabetic mice, it is not clear whether the other diabetes complications, such as liver disease and diabetic nephropathy, can also be alleviated. Here, we constructed two simple magnetic plates using neodymium permanent magnets to examine the comprehensive effects of moderate SMFs on genetically obese leptin receptor-deficient db/db diabetic mice. We found that although the blood glucose was not obviously reduced by these two SMF settings, both of the glycated serum protein (GSP) and malondialdehyde (MDA) levels were significantly decreased (Cohen’s d = 2.57–3.04). Moreover, the wound healing, liver lipid accumulation, and renal defects were all significantly improved by SMF treatment (Cohen’s d = 0.91–2.05). Wound tissue examination showed obvious nuclear factor erythroid 2-related factor 2 (NRF2) level decrease (Cohen’s d = 2.49–5.40) and Ki-67 level increase (Cohen’s d = 2.30–3.40), indicating decreased oxidative stress and increased cell proliferation. In vitro cellular studies with fibroblast NIH3T3 cells showed that SMFs could reduce high glucose-induced NRF2 nucleus translocation (Cohen’s d = 0.87–1.15) and cellular reactive oxygen species (ROS) elevation (Cohen’s d = 0.92), indicating decreased oxidative stress. Consequently, high glucose-induced impairments in cell vitality, proliferation, and migration were all improved by SMF treatment. Therefore, our results demonstrate that these simple SMF devices could effectively reduce oxidative stress in diabetic mice and may provide a cost-effective physical therapy strategy to alleviate multiple diabetic complications in the future.
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Moderate Static Magnet Fields Suppress Ovarian Cancer Metastasis via ROS-Mediated Oxidative Stress. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:7103345. [PMID: 34917231 PMCID: PMC8670934 DOI: 10.1155/2021/7103345] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Accepted: 11/08/2021] [Indexed: 11/18/2022]
Abstract
Metastasis is the leading cause of cancer patient death, which is closely correlated with reactive oxygen species (ROS) levels. It is well known that the effects of ROS on tumors are diverse, depending on ROS concentration and cell type. We found that ovarian cancer cells have significantly lower levels of ROS than normal ovarian cells. Moreover, increased ROS levels in ovarian cancer cells can substantially inhibit their migration and invasion ability. Furthermore, the results show that moderate static magnetic field (SMF) can inhibit ovarian cancer cell migration, invasion, and stemness in a ROS-dependent manner. RNA sequencing results confirm that SMFs increased the oxidative stress level and reduced the stemness of ovarian cancer cells. Consistently, the expressions of stemness-related genes were significantly decreased, including hyaluronan receptor (CD44), SRY-box transcription factor 2 (Sox2), and cell myc proto-oncogene protein (C-myc). Furthermore, moderate SMFs provided by a superconducting magnet and permanent magnet have good biosafety and can both inhibit ovarian cancer metastasis in mice. Therefore, our study demonstrates the effects of SMFs on oxidative stress and metastasis in the ovarian cancer cells, which reveals the potential of applying SMF as a physical method in cancer therapy in the future.
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Dziob D, Ramian J, Ramian J, Lisowski B, Laska J. Design and Construction of a Chamber Enabling the Observation of Living Cells in the Field of a Constant Magnetic Force. Cells 2021; 10:cells10123339. [PMID: 34943846 PMCID: PMC8699672 DOI: 10.3390/cells10123339] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 11/21/2021] [Accepted: 11/25/2021] [Indexed: 02/06/2023] Open
Abstract
The aim of the work was to design and construct a microscopic stage that enables the observation of biological cells in a magnetic field with a constant magnetic force. Regarding the requirements for biological observations in the magnetic field, construction was based on the standard automatic stage of an optical microscope ZEISS Axio Observer, and the main challenge was to design a set of magnets which were the source of a field in which the magnetic force was constant in the observation zone. Another challenge was to design a magnet arrangement producing a weak magnetic field to manipulate the cells without harming them. The Halbach array of magnets was constructed using permanent cubic neodymium magnets mounted on a 3D printed polymer ring. Four sets of magnets were used, differing in their dimensions, namely, 20, 15, 12, and 10 mm. The polymer rings were designed to resist magnetic forces and to keep their shape undisturbed when working under biological conditions. To check the usability of the constructs, experiments with magnetic microparticles were executed. Magnetic microparticles were placed under the microscope and their movement was observed to find the acting magnetic force.
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Affiliation(s)
- Daniel Dziob
- Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688 Kraków, Poland
- Correspondence:
| | - Jakub Ramian
- Faculty of Mechanical engineering and Robotics, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Kraków, Poland;
| | - Jan Ramian
- Faculty of Medical Sciences in Katowice, Medical University of Silesia, Poniatowskiego 15, 40-055 Katowice, Poland;
| | - Bartosz Lisowski
- Faculty of Medicine, Jagiellonian University Medical College, św. Łazarza 16, 31-530 Kraków, Poland;
| | - Jadwiga Laska
- Faculty of Materials Science and Ceramics, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Kraków, Poland;
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Khan MW, Juutilainen J, Naarala J, Roivainen P. Residential extremely low frequency magnetic fields and skin cancer. Occup Environ Med 2021; 79:49-54. [PMID: 34593542 DOI: 10.1136/oemed-2021-107776] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 09/07/2021] [Indexed: 11/03/2022]
Abstract
OBJECTIVE Photoinduced radical reactions have a fundamental role in skin cancer induced by ultraviolet radiation, and changes in radical reactions have also been proposed as a mechanism for the putative carcinogenic effects of extremely low frequency (ELF) magnetic fields (MFs). We assessed the association of melanoma and squamous cell carcinoma with residential MF exposure. METHODS All cohort members had lived in buildings with indoor transformer stations (TSs) during the period from 1971 to 2016. MF exposure was assessed based on apartment location. Out of the 225 492 individuals, 8617 (149 291 person-years of follow-up) living in apartments next to TSs were considered as exposed, while individuals living on higher floors of the same buildings were considered as referents. Associations between MF exposure and skin cancers were examined using Cox proportional hazard models. RESULTS The HR for MF exposure ≥6 month was 1.05 (95% CI 0.72 to 1.53) for melanoma and 0.94 (95% CI 0.55 to 1.61) for squamous cell carcinoma. Analysis of the age at the start of residence showed an elevated HR (2.55, 95% CI 1.15 to 5.69) for melanoma among those who lived in the apartments when they were less than 15 years old. This finding was based on seven exposed cases. CONCLUSIONS The results of this study suggested an association between childhood ELF MF exposure and adult melanoma. This is in agreement with previous findings suggesting that the carcinogenic effects of ELF MFs may be associated particularly with childhood exposure.
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Affiliation(s)
- Muhammad Waseem Khan
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland.,Department of Biotechnology, Balochistan University of Information Technology, Engineering and Management Sciences, Quetta, Pakistan
| | - Jukka Juutilainen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | - Jonne Naarala
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | - Päivi Roivainen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland .,Radiation and Nuclear Safety Authority (STUK), Helsinki, Finland
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Ting MS, Travas-Sejdic J, Malmström J. Modulation of hydrogel stiffness by external stimuli: soft materials for mechanotransduction studies. J Mater Chem B 2021; 9:7578-7596. [PMID: 34596202 DOI: 10.1039/d1tb01415c] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Mechanotransduction is an important process in determining cell survival, proliferation, migration and differentiation. The extracellular matrix (ECM) is the component of natural tissue that provides structural support and biochemical signals to adhering cells. The ECM is dynamic and undergoes physical and biochemical changes in response to various stimuli and there is an interest in understanding the effect of dynamic changes in stiffness on cell behaviour and fate. Therefore, stimuli-responsive hydrogels have been developed to mimic the cells' microenvironment in a controlled fashion. Herein, we review strategies for dynamic modulation of stiffness using various stimuli, such as light, temperature and pH. Special emphasis is placed on conducting polymer (CP) hydrogels and their fabrication procedures. We believe that the redox properties of CPs and hydrogels' biological properties make CPs hydrogels a promising substrate to investigate the effect of dynamic stiffness changes and mechanical actuation on cell fate in future studies.
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Affiliation(s)
- Matthew S Ting
- Department of Chemical and Materials Engineering, The University of Auckland, Auckland, New Zealand. .,MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington, New Zealand.,Polymer Biointerface Centre, School of Chemical Sciences, The University of Auckland, Auckland, New Zealand
| | - Jadranka Travas-Sejdic
- MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington, New Zealand.,Polymer Biointerface Centre, School of Chemical Sciences, The University of Auckland, Auckland, New Zealand
| | - Jenny Malmström
- Department of Chemical and Materials Engineering, The University of Auckland, Auckland, New Zealand. .,MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington, New Zealand.,Polymer Biointerface Centre, School of Chemical Sciences, The University of Auckland, Auckland, New Zealand
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Abstract
Species throughout the animal kingdom use the Earth's magnetic field (MF) to navigate using either or both of two mechanisms. The first relies on magnetite crystals in tissue where their magnetic moments align with the MF to transduce a signal transmitted to the central nervous system. The second and the subject of this paper involves cryptochrome (CRY) proteins located in cone photoreceptors distributed across the retina, studied most extensively in birds. According to the "Radical Pair Mechanism" (RPM), blue/UV light excites CRY's flavin cofactor (FAD) to generate radical pairs whose singlet-to-triplet interconversion rate is modulated by an external MF. The signaling product of the RPM produces an impression of the field across the retinal surface. In birds, the resulting signal on the optic nerve is transmitted along the thalamofugal pathway to the primary visual cortex, which projects to brain regions concerned with image processing, memory, and executive function. The net result is a bird's orientation to the MF's inclination: its vector angle relative to the Earth's surface. The quality of ambient light (e.g., polarization) provides additional input to the compass. In birds, the Type IV CRY isoform appears pivotal to the compass, given its positioning within retinal cones; a cytosolic location therein indicating no role in the circadian clock; relatively steady diurnal levels (unlike Type II CRY's cycling); and a full complement of FAD (essential for photosensitivity). The evidence indicates that mammalian Type II CRY isoforms play a light-independent role in the cellular molecular clock without a photoreceptive function.
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Affiliation(s)
| | - Joseph Brain
- Environmental Physiology, Molecular, and Integrative Physiological Sciences Program, Department of Environmental Health, Harvard T. H. Chan School of Public Health, Boston, Massachusetts
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