1
|
Gul A, Ahmad M, Ullah R, Ullah R, Kang Y, Liao W. Systematic review on antibacterial photodynamic therapeutic effects of transition metals ruthenium and iridium complexes. J Inorg Biochem 2024; 255:112523. [PMID: 38489864 DOI: 10.1016/j.jinorgbio.2024.112523] [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: 12/03/2023] [Revised: 02/29/2024] [Accepted: 03/10/2024] [Indexed: 03/17/2024]
Abstract
The prevalence of antibiotic-resistant pathogenic bacteria poses a significant threat to public health and ranks among the principal causes of morbidity and mortality worldwide. Antimicrobial photodynamic therapy is an emerging therapeutic technique that has excellent potential to embark upon antibiotic resistance problems. The efficacy of this therapy hinges on the careful selection of suitable photosensitizers (PSs). Transition metal complexes, such as Ruthenium (Ru) and Iridium (Ir), are highly suitable for use as PSs because of their surface plasmonic resonance, crystal structure, optical characteristics, and photonics. These metals belong to the platinum family and exhibit similar chemical behavior due to their partially filled d-shells. Ruthenium and Iridium-based complexes generate reactive oxygen species (ROS), which interact with proteins and DNA to induce cell death. As photodynamic therapeutic agents, these complexes have been widely studied for their efficacy against cancer cells, but their potential for antibacterial activity remains largely unexplored. Our study focuses on exploring the antibacterial photodynamic effect of Ruthenium and Iridium-based complexes against both Gram-positive and Gram-negative bacteria. We aim to provide a comprehensive overview of various types of research in this area, including the structures, synthesis methods, and antibacterial photodynamic applications of these complexes. Our findings will provide valuable insights into the design, development, and modification of PSs to enhance their photodynamic therapeutic effect on bacteria, along with a clear understanding of their mechanism of action.
Collapse
Affiliation(s)
- Anadil Gul
- College of Applied Sciences, Shenzhen University, Shenzhen 518060, China; Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, National-Regional Key Technology Engineering Laboratory for Medical Ultrasound, School of Biomedical Engineering, Shenzhen University Medical School, Shenzhen 518060, China; College of Health Science and Environmental Engineering, Shenzhen Technology University, Pingshan District, Shenzhen 518118, China
| | - Munir Ahmad
- Shenzhen Key Laboratory of Advanced Thin Films and Applications, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, Guangdong, China
| | - Raza Ullah
- College of Materials Science and Engineering, Institute of Biomedical Materials and Engineering, Qingdao University, Qingdao 266071, China
| | - Rizwan Ullah
- School of Physics, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Yan Kang
- College of Applied Sciences, Shenzhen University, Shenzhen 518060, China; Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, National-Regional Key Technology Engineering Laboratory for Medical Ultrasound, School of Biomedical Engineering, Shenzhen University Medical School, Shenzhen 518060, China; College of Health Science and Environmental Engineering, Shenzhen Technology University, Pingshan District, Shenzhen 518118, China.
| | - Wenchao Liao
- College of Health Science and Environmental Engineering, Shenzhen Technology University, Pingshan District, Shenzhen 518118, China.
| |
Collapse
|
2
|
Fasciani I, Petragnano F, Bono F, Aloisi G, Mutti V, Pardini C, Carli M, Scarselli M, Vaglini F, Angelucci A, Fiorentini C, Lozzi L, Missale C, Maggio R, Rossi M. In-vitro Approaches to Investigate the Detrimental Effect of Light on Dopaminergic Neurons. Neuroscience 2024; 544:104-116. [PMID: 38244669 DOI: 10.1016/j.neuroscience.2024.01.009] [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: 09/23/2023] [Revised: 01/08/2024] [Accepted: 01/11/2024] [Indexed: 01/22/2024]
Abstract
Our recent study revealed that fluorescent lamp light can penetrate deep into the brain of mice and rats leading to the development of typical histological characteristics associated with Parkinson's disease such as the loss of dopamine neurons in the substantia nigra. Monochromatic LED lights were thus used in this work to deepen our knowledge on the effects of the major wavelength peaks of fluorescent light on mouse and human dopaminergic cells. In particular, we exposed immortalized dopaminergic MN9D neuronal cells, primary cultures of mouse mesencephalic dopaminergic cells and human dopaminergic neurons differentiated from induced pluripotent stem cells (hiPSC) to different LED light wavelengths. We found that chronic exposure to LED light reduced overall undifferentiated MN9D cell number, with the most significant effects observed at wavelengths of 485 nm and 610 nm. Moreover, LED light especially at 610 nm was able to negatively impact on the survival of mouse mesencephalic dopaminergic cells and of human dopaminergic neurons derived from hiPSC. Notably, differentiated MN9D dopaminergic cells, which closely resemble mature dopamine neuronal phenotype, acutely exposed for 3 h at 610 nm, showed a clear increase in ROS production and cytotoxicity compared to controls undifferentiated MN9D cells. These increases were even more pronounced by the co-treatment with the oxidative agent H2O2. Collectively, these findings suggest that specific wavelengths, particularly those capable of penetrating deep into the brain, could potentially pose an environmental hazard in relation to Parkinson's disease.
Collapse
Affiliation(s)
- Irene Fasciani
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, 67100 L'Aquila, Italy
| | - Francesco Petragnano
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, 67100 L'Aquila, Italy
| | - Federica Bono
- Section of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123 Brescia, Italy
| | - Gabriella Aloisi
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, 67100 L'Aquila, Italy
| | - Veronica Mutti
- Section of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123 Brescia, Italy
| | - Carla Pardini
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Marco Carli
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Marco Scarselli
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Francesca Vaglini
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Adriano Angelucci
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, 67100 L'Aquila, Italy
| | - Chiara Fiorentini
- Section of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123 Brescia, Italy
| | - Luca Lozzi
- Department of Physical and Chemical Science, University of L'Aquila, via Vetoio, Coppito, 67100 L'Aquila, Italy
| | - Cristina Missale
- Section of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123 Brescia, Italy
| | - Roberto Maggio
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, 67100 L'Aquila, Italy
| | - Mario Rossi
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, 67100 L'Aquila, Italy.
| |
Collapse
|
3
|
Munoz-Robles BG, DeForest CA. Irreversible light-activated SpyLigation mediates split-protein assembly in 4D. Nat Protoc 2024; 19:1015-1052. [PMID: 38253657 PMCID: PMC11288621 DOI: 10.1038/s41596-023-00938-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 10/23/2023] [Indexed: 01/24/2024]
Abstract
The conditional assembly of split-protein pairs to modulate biological activity is commonly achieved by fusing split-protein fragments to dimerizing components that bring inactive pairs into close proximity in response to an exogenous trigger. However, current methods lack full spatial and temporal control over reconstitution, require sustained activation and lack specificity. Here light-activated SpyLigation (LASL), based on the photoregulation of the covalent SpyTag (ST)/SpyCatcher (SC) peptide-protein reaction, assembles nonfunctional split fragment pairs rapidly and irreversibly in solution, in engineered biomaterials and intracellularly. LASL introduces an ortho-nitrobenzyl(oNB)-caged lysine into SC's reactive site to generate a photoactivatable SC (pSC). Split-protein pairs of interest fused to pSC and ST are conditionally assembled via near-ultraviolet or pulsed near-infrared irradiation, as the uncaged SC can react with ST to ligate appended fragments. We describe procedures for the efficient synthesis of the photocaged amino acid that is incorporated within pSC (<5 days) as well as the design and cloning of LASL plasmids (1-4 days) for recombinant protein expression in either Escherichia coli (5-6 days) or mammalian cells (4-6 days), which require some prior expertise in protein engineering. We provide a chemoenzymatic scheme for appending bioorthogonal reactive handles onto E. coli-purified pSC protein (<4 days) that permits LASL component incorporation and patterned protein activation within many common biomaterial platforms. Given that LASL is irreversible, the photolithographic patterning procedures are fast and do not require sustained light exposure. Overall, LASL can be used to interrogate and modulate cell signaling in various settings.
Collapse
Affiliation(s)
- Brizzia G Munoz-Robles
- Department of Bioengineering, University of Washington, Seattle, WA, USA
- Institute of Stem Cell & Regenerative Medicine, University of Washington, Seattle, WA, USA
| | - Cole A DeForest
- Department of Bioengineering, University of Washington, Seattle, WA, USA.
- Institute of Stem Cell & Regenerative Medicine, University of Washington, Seattle, WA, USA.
- Department of Chemical Engineering, University of Washington, Seattle, WA, USA.
- Department of Chemistry, University of Washington, Seattle, WA, USA.
- Molecular Engineering & Sciences Institute, University of Washington, Seattle, WA, USA.
- Institute for Protein Design, University of Washington, Seattle, WA, USA.
| |
Collapse
|
4
|
Fan L, Wang C, Wang J, Zhang X, Li Q, Wang H, Zhao YH. Photolysis and photo-enhanced toxicity of three novel designed neonicotinoids: Impact of novel modifying groups. JOURNAL OF HAZARDOUS MATERIALS 2023; 459:132132. [PMID: 37494794 DOI: 10.1016/j.jhazmat.2023.132132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 06/29/2023] [Accepted: 07/21/2023] [Indexed: 07/28/2023]
Abstract
Three novel neonicotinoids (cycloxaprid, flupyradifurone and sulfoxaflor) were designed to reduce the biotoxicity for non-target organisms. These neonicotinoids were photolyzed under light radiation, but it was unclear for the photo-enhanced toxicity and influences of the novel modifying group of the three neonicotinoids. The photolysis and photo-enhanced toxicity experiments were performed for the three neonicotinoids, coupled with quantum chemistry calculation, the mechanisms of photolysis, photo-enhanced toxicity and the influences of novel modifying groups were analyzed. The results showed the photolysis pathways were enriched as compared with previous neonicotinoids due to the composition of modifying groups, singlet oxygen and hydroxyl participated the photolysis of cycloxaprid and flupyradifurone. All tested neonicotinoids exhibited photo-enhanced toxicity to Vibrio fischeri. Due to the difference of photolysis mechanism and toxicity to V. fischeri, the photo-enhanced toxicity curves showed diverse variation when histidine, tert-butanol or dissolved organic matters was in presence of the test solutions. The impact of novel modifying groups over photolysis and photo-enhanced toxicity were analyzed based on the comparison with previous neonicotinoids, theoretically predicted UV-Vis spectra and photo-physical/chemical property descriptors. The data showed the composition of novel modifying group increased the light absorption and photo-chemical activities for the three neonicotinoids.
Collapse
Affiliation(s)
- Lingyun Fan
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun 130117, China; Heilongjiang Province Key Laboratory of Geographical Environment Monitoring and Spatial Information Service in Cold Regions, Heilongjiang Province Collaborative Innovation Center of Cold Region Ecological Safety, School of Geographical Sciences, Harbin Normal University, Harbin 150025, China
| | - Chen Wang
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun 130117, China
| | - Jia Wang
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun 130117, China
| | - Xujia Zhang
- Heilongjiang Province Key Laboratory of Geographical Environment Monitoring and Spatial Information Service in Cold Regions, Heilongjiang Province Collaborative Innovation Center of Cold Region Ecological Safety, School of Geographical Sciences, Harbin Normal University, Harbin 150025, China
| | - Qi Li
- School of Environmental Science & Engineering, Yancheng Institute of Technology, Yancheng 224051, China
| | - Hanxi Wang
- Heilongjiang Province Key Laboratory of Geographical Environment Monitoring and Spatial Information Service in Cold Regions, Heilongjiang Province Collaborative Innovation Center of Cold Region Ecological Safety, School of Geographical Sciences, Harbin Normal University, Harbin 150025, China.
| | - Yuan Hui Zhao
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun 130117, China.
| |
Collapse
|
5
|
Fonseca M, Rehman M, Soares R, Fonte P. The Impact of Flavonoid-Loaded Nanoparticles in the UV Protection and Safety Profile of Topical Sunscreens. Biomolecules 2023; 13:biom13030493. [PMID: 36979428 PMCID: PMC10046639 DOI: 10.3390/biom13030493] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 02/14/2023] [Accepted: 02/17/2023] [Indexed: 03/10/2023] Open
Abstract
Excessive UV radiation exposure is harmful to skin cells since sunburn is accompanied by oxidative burst, leading to a rapid increase in skin cancer. However, the insufficient UV photoprotection of approved sunscreens and the negative impact of their compositions on ecosystems and human health makes the utility of sunscreen a questionable recommendation. Therefore, discovering UV filters with significant antioxidant activity and improved topical performance and photostability is an urgent need. Recently, the use of nanosized natural molecules incorporated in sunscreens has been a scientific hot topic, as it has been suggested that they provide a synergistic effect with synthetic UV filters, improving overall SPF and antioxidant activity, higher retention on the epidermis, and less toxicity. The aim of this review was to verify the usefulness of sunscreens incorporating flavonoid-loaded nanoparticles. A literature review was performed, where original and review articles published in the last 6 years were analyzed. Formulations containing nanosized flavonoids with improved UVA photoprotection and safer toxicological profiles, associated or not with synthetic filters, are promising sunscreens and more clinical investigation must be performed to validate these findings.
Collapse
Affiliation(s)
- Magda Fonseca
- EPI Unit, Department of Epidemiological Research, Institute of Public Health of University of Porto (ISPUP), Rua das Taipas 135, 4050-600 Porto, Portugal
| | - Mubashar Rehman
- Department of Pharmacy, Quaid-i-Azam University, Islamabad 45320, Pakistan
| | - Raquel Soares
- Department of Biomedicine, Faculty of Medicine, University of Porto, Al Prof Hernani Monteiro, 4200-319 Porto, Portugal
- I3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal
| | - Pedro Fonte
- Center for Marine Sciences (CCMAR), Gambelas Campus, University of Algarve, 8005-139 Faro, Portugal
- Department of Chemistry and Pharmacy, Faculty of Sciences and Technology, Gambelas Campus, University of Algarve, 8005-139 Faro, Portugal
- IBB—Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
- Associate Laboratory i4HB—Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
- Correspondence:
| |
Collapse
|
6
|
Piksa M, Lian C, Samuel IC, Pawlik KJ, Samuel IDW, Matczyszyn K. The role of the light source in antimicrobial photodynamic therapy. Chem Soc Rev 2023; 52:1697-1722. [PMID: 36779328 DOI: 10.1039/d0cs01051k] [Citation(s) in RCA: 74] [Impact Index Per Article: 74.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Antimicrobial photodynamic therapy (APDT) is a promising approach to fight the growing problem of antimicrobial resistance that threatens health care, food security and agriculture. APDT uses light to excite a light-activated chemical (photosensitiser), leading to the generation of reactive oxygen species (ROS). Many APDT studies confirm its efficacy in vitro and in vivo against bacteria, fungi, viruses and parasites. However, the development of the field is focused on exploring potential targets and developing new photosensitisers. The role of light, a crucial element for ROS production, has been neglected. What are the main parameters essential for effective photosensitiser activation? Does an optimal light radiant exposure exist? And finally, which light source is best? Many reports have described the promising antibacterial effects of APDT in vitro, however, its application in vivo, especially in clinical settings remains very limited. The restricted availability may partially be due to a lack of standard conditions or protocols, arising from the diversity of selected photosensitising agents (PS), variable testing conditions including light sources used for PS activation and methods of measuring anti-bacterial activity and their effectiveness in treating bacterial infections. We thus sought to systematically review and examine the evidence from existing studies on APDT associated with the light source used. We show how the reduction of pathogens depends on the light source applied, radiant exposure and irradiance of light used, and type of pathogen, and so critically appraise the current state of development of APDT and areas to be addressed in future studies. We anticipate that further standardisation of the experimental conditions will help the field advance, and suggest key optical and biological parameters that should be reported in all APDT studies. More in vivo and clinical studies are needed and are expected to be facilitated by advances in light sources, leading to APDT becoming a sustainable, alternative therapeutic option for bacterial and other microbial infections in the future.
Collapse
Affiliation(s)
- Marta Piksa
- Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Science, Weigla 12, 53-114, Wroclaw, Poland
| | - Cheng Lian
- Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St Andrews, Fife, KY16 9SS, UK.
| | - Imogen C Samuel
- School of Medicine, University of Manchester, Manchester, M13 9PL, UK
| | - Krzysztof J Pawlik
- Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Science, Weigla 12, 53-114, Wroclaw, Poland
| | - Ifor D W Samuel
- Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St Andrews, Fife, KY16 9SS, UK.
| | - Katarzyna Matczyszyn
- Institute of Advanced Materials, Faculty of Chemistry, Wroclaw University of Science and Technology, Wyb. Wyspianskiego 27, 50-370 Wroclaw, Poland.
| |
Collapse
|
7
|
Kvam E, Davis B, Benner K. Comparative Assessment of Pulsed and Continuous LED UV-A Lighting for Disinfection of Contaminated Surfaces. Life (Basel) 2022; 12:1747. [PMID: 36362902 PMCID: PMC9696731 DOI: 10.3390/life12111747] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 10/23/2022] [Accepted: 10/29/2022] [Indexed: 08/27/2023] Open
Abstract
The germicidal efficacy of LED UV-A lighting has scarcely been compared in continuous and pulsed modes for contaminated surfaces. Herein, we compare the disinfection properties of pulsed versus continuous lighting at equal irradiances using a 365 nm LED device that replicates the doses of occupied-space continuous disinfection UV-A products. Representative organisms evaluated in this study included human-infectious enveloped and non-enveloped viruses (lentivirus and adeno-associated virus, respectively), a bacterial endospore (Bacillus atrophaeus), and a resilient gram-positive bacterium (Enterococcus faecalis). Nominal UV-A irradiances were tested at or below the UL standard limit for continuous human exposure (maximum irradiance of 10 W/m2). We observed photoinactivation properties that varied by organism type, with bacteria and enveloped virus being more susceptible to UV-A than non-enveloped virus and spores. Overall, we conclude that continuous-mode UV-A lighting is better suited for occupied-space disinfection than pulsing UV-A at equivalent low irradiances, and we draw comparisons to other studies in the literature.
Collapse
Affiliation(s)
- Erik Kvam
- GE Research, One Research Circle, K1 5D29, Niskayuna, NY 12309, USA
| | - Brian Davis
- GE Research, One Research Circle, K1 5D29, Niskayuna, NY 12309, USA
| | | |
Collapse
|
8
|
Petrus P, Cervantes M, Samad M, Sato T, Chao A, Sato S, Koronowski KB, Park G, Alam Y, Mejhert N, Seldin MM, Monroy Kuhn JM, Dyar KA, Lutter D, Baldi P, Kaiser P, Jang C, Sassone-Corsi P. Tryptophan metabolism is a physiological integrator regulating circadian rhythms. Mol Metab 2022; 64:101556. [PMID: 35914650 PMCID: PMC9382333 DOI: 10.1016/j.molmet.2022.101556] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 07/15/2022] [Accepted: 07/15/2022] [Indexed: 01/20/2023] Open
Abstract
OBJECTIVE The circadian clock aligns physiology with the 24-hour rotation of Earth. Light and food are the main environmental cues (zeitgebers) regulating circadian rhythms in mammals. Yet, little is known about the interaction between specific dietary components and light in coordinating circadian homeostasis. Herein, we focused on the role of essential amino acids. METHODS Mice were fed diets depleted of specific essential amino acids and their behavioral rhythms were monitored and tryptophan was selected for downstream analyses. The role of tryptophan metabolism in modulating circadian homeostasis was studied using isotope tracing as well as transcriptomic- and metabolomic- analyses. RESULTS Dietary tryptophan depletion alters behavioral rhythms in mice. Furthermore, tryptophan metabolism was shown to be regulated in a time- and light- dependent manner. A multi-omics approach and combinatory diet/light interventions demonstrated that tryptophan metabolism modulates temporal regulation of metabolism and transcription programs by buffering photic cues. Specifically, tryptophan metabolites regulate central circadian functions of the suprachiasmatic nucleus and the core clock machinery in the liver. CONCLUSIONS Tryptophan metabolism is a modulator of circadian homeostasis by integrating environmental cues. Our findings propose tryptophan metabolism as a potential point for pharmacologic intervention to modulate phenotypes associated with disrupted circadian rhythms.
Collapse
Affiliation(s)
- Paul Petrus
- Center for Epigenetics and Metabolism, U1233 INSERM, Department of Biological Chemistry, University of California, Irvine, Irvine, CA 92697, USA.
| | - Marlene Cervantes
- Center for Epigenetics and Metabolism, U1233 INSERM, Department of Biological Chemistry, University of California, Irvine, Irvine, CA 92697, USA.
| | - Muntaha Samad
- Institute for Genomics and Bioinformatics, Department of Computer Science, University of California Irvine (UCI), Irvine, CA, USA
| | - Tomoki Sato
- Center for Epigenetics and Metabolism, U1233 INSERM, Department of Biological Chemistry, University of California, Irvine, Irvine, CA 92697, USA
| | - Alina Chao
- Department of Biological Chemistry, Chao Family Comprehensive Cancer Center, University of California Irvine, Irvine, CA 92697, USA
| | - Shogo Sato
- Center for Epigenetics and Metabolism, U1233 INSERM, Department of Biological Chemistry, University of California, Irvine, Irvine, CA 92697, USA
| | - Kevin B Koronowski
- Center for Epigenetics and Metabolism, U1233 INSERM, Department of Biological Chemistry, University of California, Irvine, Irvine, CA 92697, USA
| | - Grace Park
- Department of Biological Chemistry, Chao Family Comprehensive Cancer Center, University of California Irvine, Irvine, CA 92697, USA
| | - Yasmine Alam
- Department of Biological Chemistry, Chao Family Comprehensive Cancer Center, University of California Irvine, Irvine, CA 92697, USA
| | - Niklas Mejhert
- Department of Medicine (H7), Karolinska Institutet, C2-94, Karolinska University Hospital, 141 86 Stockholm, Sweden
| | - Marcus M Seldin
- Center for Epigenetics and Metabolism, Department of Biological Chemistry, University of California, Irvine, CA, USA
| | - José Manuel Monroy Kuhn
- Computational Discovery Research, Institute for Diabetes and Obesity (IDO), Helmholtz Diabetes Center (HDC), Helmholtz Zentrum Munich - German Research Center for Environmental Health, 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany
| | - Kenneth A Dyar
- German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany; Metabolic Physiology, Institute for Diabetes and Cancer (IDC), Helmholtz Diabetes Center, Helmholtz Zentrum Munich - German Research Center for Environmental Health, 85764 Neuherberg, Germany
| | - Dominik Lutter
- Computational Discovery Research, Institute for Diabetes and Obesity (IDO), Helmholtz Diabetes Center (HDC), Helmholtz Zentrum Munich - German Research Center for Environmental Health, 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany
| | - Pierre Baldi
- Institute for Genomics and Bioinformatics, Department of Computer Science, University of California Irvine (UCI), Irvine, CA, USA
| | - Peter Kaiser
- Department of Biological Chemistry, School of Medicine, University of California Irvine, Irvine, CA, USA
| | - Cholsoon Jang
- Department of Biological Chemistry, Chao Family Comprehensive Cancer Center, University of California Irvine, Irvine, CA 92697, USA
| | - Paolo Sassone-Corsi
- Center for Epigenetics and Metabolism, U1233 INSERM, Department of Biological Chemistry, University of California, Irvine, Irvine, CA 92697, USA
| |
Collapse
|
9
|
Bauer R, Hoenes K, Meurle T, Hessling M, Spellerberg B. The effects of violet and blue light irradiation on ESKAPE pathogens and human cells in presence of cell culture media. Sci Rep 2021; 11:24473. [PMID: 34963696 PMCID: PMC8714816 DOI: 10.1038/s41598-021-04202-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 12/16/2021] [Indexed: 12/18/2022] Open
Abstract
Bacteria belonging to the group of ESKAPE pathogens are responsible for the majority of nosocomial infections. Due to the increase of antibiotic resistance, alternative treatment strategies are of high clinical relevance. In this context visible light as disinfection technique represents an interesting option as microbial pathogens can be inactivated without adjuvants. However cytotoxic effects of visible light on host cells have also been reported. We compared the cytotoxicity of violet and blue light irradiation on monocytic THP-1 and alveolar epithelium A549 cells with the inactivation effect on ESKAPE pathogens. THP-1 cells displayed a higher susceptibility to irradiation than A549 cells with first cytotoxic effects occurring at 300 J cm−2 (405 nm) and 400 J cm−2 (450 nm) in comparison to 300 J cm−2 and 1000 J cm−2, respectively. We could define conditions in which a significant reduction of colony forming units for all ESKAPE pathogens, except Enterococcus faecium, was achieved at 405 nm while avoiding cytotoxicity. Irradiation at 450 nm demonstrated a more variable effect which was species and medium dependent. In summary a significant reduction of viable bacteria could be achieved at subtoxic irradiation doses, supporting a potential use of visible light as an antimicrobial agent in clinical settings.
Collapse
Affiliation(s)
- Richard Bauer
- Institute of Medical Microbiology and Hygiene, University Hospital Ulm, 89081, Ulm, Germany
| | - Katharina Hoenes
- Institute of Medical Engineering and Mechatronics, Ulm University of Applied Sciences, 89081, Ulm, Germany
| | - Tobias Meurle
- Institute of Medical Engineering and Mechatronics, Ulm University of Applied Sciences, 89081, Ulm, Germany
| | - Martin Hessling
- Institute of Medical Engineering and Mechatronics, Ulm University of Applied Sciences, 89081, Ulm, Germany
| | - Barbara Spellerberg
- Institute of Medical Microbiology and Hygiene, University Hospital Ulm, 89081, Ulm, Germany.
| |
Collapse
|
10
|
Darrah KE, Deiters A. Translational control of gene function through optically regulated nucleic acids. Chem Soc Rev 2021; 50:13253-13267. [PMID: 34739027 DOI: 10.1039/d1cs00257k] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Translation of mRNA into protein is one of the most fundamental processes within biological systems. Gene expression is tightly regulated both in space and time, often involving complex signaling or gene regulatory networks, as most prominently observed in embryo development. Thus, studies of gene function require tools with a matching level of external control. Light is an excellent conditional trigger as it is minimally invasive, can be easily tuned in wavelength and amplitude, and can be applied with excellent spatial and temporal resolution. To this end, modification of established oligonucleotide-based technologies with optical control elements, in the form of photocaging groups and photoswitches, has rendered these tools capable of navigating the dynamic regulatory pathways of mRNA translation in cellular and in vivo models. In this review, we discuss the different optochemical approaches used to generate photoresponsive nucleic acids that activate and deactivate gene expression and function at the translational level.
Collapse
Affiliation(s)
- Kristie E Darrah
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania, 15260, USA.
| | - Alexander Deiters
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania, 15260, USA.
| |
Collapse
|
11
|
Mayrhofer P, Reinhart D, Castan A, Kunert R. Monitoring of heat- and light exposure of cell culture media by RAMAN spectroscopy: Towards an analytical tool for cell culture media quality control. Biochem Eng J 2021. [DOI: 10.1016/j.bej.2020.107845] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
12
|
Kolarski D, Sugiyama A, Rodat T, Schulte A, Peifer C, Itami K, Hirota T, Feringa BL, Szymanski W. Reductive stability evaluation of 6-azopurine photoswitches for the regulation of CKIα activity and circadian rhythms. Org Biomol Chem 2021; 19:2312-2321. [DOI: 10.1039/d1ob00014d] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
6-Azopurines were evaluated for their reductive stability, and the ability to modulate CKIα activity and cellular circadian rhythms, revealing key challenges for long-term activity modulation utilizing chronophotopharmacology.
Collapse
Affiliation(s)
- Dušan Kolarski
- Stratingh Institute for Chemistry
- University of Groningen
- Groningen
- The Netherlands
| | - Akiko Sugiyama
- Institute of Transformative Bio-Molecules (WPI-ITbM)
- Nagoya University
- Nagoya 464-8601
- Japan
| | - Theo Rodat
- Department of Pharmaceutical and Medicinal Chemistry
- Christian-Albrechts-University of Kiel
- 24118 Kiel
- Germany
| | - Albert Schulte
- Stratingh Institute for Chemistry
- University of Groningen
- Groningen
- The Netherlands
| | - Christian Peifer
- Department of Pharmaceutical and Medicinal Chemistry
- Christian-Albrechts-University of Kiel
- 24118 Kiel
- Germany
| | - Kenichiro Itami
- Institute of Transformative Bio-Molecules (WPI-ITbM)
- Nagoya University
- Nagoya 464-8601
- Japan
| | - Tsuyoshi Hirota
- Institute of Transformative Bio-Molecules (WPI-ITbM)
- Nagoya University
- Nagoya 464-8601
- Japan
| | - Ben L. Feringa
- Stratingh Institute for Chemistry
- University of Groningen
- Groningen
- The Netherlands
| | - Wiktor Szymanski
- Stratingh Institute for Chemistry
- University of Groningen
- Groningen
- The Netherlands
- Medical Imaging Center
| |
Collapse
|
13
|
Bellmaine S, Schnellbaecher A, Zimmer A. Reactivity and degradation products of tryptophan in solution and proteins. Free Radic Biol Med 2020; 160:696-718. [PMID: 32911085 DOI: 10.1016/j.freeradbiomed.2020.09.002] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 08/06/2020] [Accepted: 09/02/2020] [Indexed: 12/13/2022]
Abstract
Tryptophan is one of the essential mammalian amino acids and is thus a required component in human nutrition, animal feeds, and cell culture media. However, this aromatic amino acid is highly susceptible to oxidation and is known to degrade into multiple products during manufacturing, storage, and processing. Many physical and chemical processes contribute to the degradation of this compound, primarily via oxidation or cleavage of the highly reactive indole ring. The central contributing factors are reactive oxygen species, such as singlet oxygen, hydrogen peroxide, and hydroxyl radicals; light and photosensitizers; metals; and heat. In a multi-component mixture, tryptophan also commonly reacts with carbonyl-containing compounds, leading to a wide variety of products. The purpose of this review is to summarize the current state of knowledge regarding the degradation and interaction products of tryptophan in complex liquid solutions and in proteins. For the purposes of context, a brief summary of the key pathways in tryptophan metabolism will be included, along with common methods and issues in tryptophan manufacturing. The review will focus on the conditions that lead to tryptophan degradation, the products generated in these processes, their known biological effects, and methods which may be applied to stabilize the amino acid.
Collapse
Affiliation(s)
- Stephanie Bellmaine
- Merck Life Science, Upstream R&D, Frankfurter Strasse 250, 64293, Darmstadt, Germany
| | - Alisa Schnellbaecher
- Merck Life Science, Upstream R&D, Frankfurter Strasse 250, 64293, Darmstadt, Germany
| | - Aline Zimmer
- Merck Life Science, Upstream R&D, Frankfurter Strasse 250, 64293, Darmstadt, Germany.
| |
Collapse
|
14
|
Giacomoni PU. Appropriate Technologies to Accompany Sunscreens in the Battle Against Ultraviolet, Superoxide, and Singlet Oxygen. Antioxidants (Basel) 2020; 9:antiox9111091. [PMID: 33172011 PMCID: PMC7694687 DOI: 10.3390/antiox9111091] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 10/31/2020] [Accepted: 11/04/2020] [Indexed: 12/19/2022] Open
Abstract
The interaction of ultraviolet radiation with biological matter results in direct damage such as pyrimidine dimers in DNA. It also results in indirect damage provoked by the production of reactive oxygen species (ROS) catalyzed by photosensitizers. Photosensitizers can be endogenous (e.g., tryptophan) or exogenous (e.g., TiO2 and other photostable UVA sunscreens). Direct damage triggers an inflammatory response and the oxidative and proteolytic bursts that characterize its onset. The inflammatory reaction multiplies the effects of one single photon. Indirect damage, such as the peroxidative cascade in membrane lipids, can extend to thousands of molecular modifications per absorbed photon. Sunscreens should therefore be formulated in the presence of appropriate antioxidants. Superoxide and singlet oxygen are the main ROS that need to be tackled: this review describes some of the molecular, biochemical, cellular, and clinical consequences of exposure to UV radiation as well as some results associated with scavengers and quenchers of superoxide and singlet oxygen, as well as with inhibitors of singlet oxygen production.
Collapse
|
15
|
Kvam E, Benner K. Mechanistic insights into UV-A mediated bacterial disinfection via endogenous photosensitizers. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2020; 209:111899. [PMID: 32485344 DOI: 10.1016/j.jphotobiol.2020.111899] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 05/13/2020] [Accepted: 05/15/2020] [Indexed: 01/09/2023]
Abstract
UV-A and visible light are thought to excite endogenous photosensitizers in microbes, thereby initiating complex chemical interactions that ultimately kill cells. Natural solar-based disinfection methods have been adapted into commercial lighting technologies with varying degrees of reported efficacy and associated safety hazards for human exposure. Here we utilize a narrow-spectrum UV-A LED prototype (currently in development for health care applications) to investigate the mechanism of bacterial photoinactivation using 365 nm light. Using a combination of reverse genetics and biochemical investigation, we report mechanistic evidence that 365nm light initiates a chain-reaction of superoxide-mediated damage via auto-excitation of vitamin-based electron carriers, specifically vitamin K2 menaquinones and the FAD flavoprotein in Complex II in the electron transport chain. We observe that photoinactivation is modifiable through supplementation of the environment to bypass cell damage. Lastly, we observe that bacteria forced into metabolic dormancy by desiccation become hypersensitized to the effects of UV-A light, thereby permitting photoinactivation at fluences that are significantly lower than the industry threshold for safe human exposure. In total, these results substantiate the mechanism and potential application of narrow- spectrum UV-A light for bacterial disinfection purposes.
Collapse
Affiliation(s)
- Erik Kvam
- GE Research, One Research Circle, Niskayuna, NY 12309, USA.
| | - Kevin Benner
- GE Current, a Daintree Company, East Cleveland, OH 44112, USA
| |
Collapse
|
16
|
Wallace A, Trimble S, Valliere-Douglass JF, Allen M, Eakin C, Balland A, Reddy P, Treuheit MJ. Control of Antibody Impurities Induced by Riboflavin in Culture Media During Production. J Pharm Sci 2020; 109:566-575. [DOI: 10.1016/j.xphs.2019.10.039] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 10/15/2019] [Accepted: 10/22/2019] [Indexed: 11/28/2022]
|
17
|
Hammill ML, Islam G, Desaulniers JP. Reversible control of RNA interference by siRNAzos. Org Biomol Chem 2020; 18:41-46. [DOI: 10.1039/c9ob02509j] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In this study, we report the reversible control of RNA interference using siRNAzos, a class of siRNAs that contain azobenzene.
Collapse
Affiliation(s)
- Matthew L. Hammill
- University of Ontario Institute of Technology
- Faculty of Science
- Oshawa
- Canada
| | - Golam Islam
- University of Ontario Institute of Technology
- Faculty of Science
- Oshawa
- Canada
| | | |
Collapse
|
18
|
Abu-Laban M, Hamal P, Arrizabalaga JH, Forghani A, Dikkumbura AS, Kumal RR, Haber LH, Hayes DJ. Combinatorial Delivery of miRNA-Nanoparticle Conjugates in Human Adipose Stem Cells for Amplified Osteogenesis. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2019; 15:e1902864. [PMID: 31725198 PMCID: PMC8530457 DOI: 10.1002/smll.201902864] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Revised: 10/15/2019] [Indexed: 05/25/2023]
Abstract
It is becoming more apparent in tissue engineering applications that fine temporal control of multiple therapeutics is desirable to modulate progenitor cell fate and function. Herein, the independent temporal control of the co-delivery of miR-148b and miR-21 mimic plasmonic nanoparticle conjugates to induce osteogenic differentiation of human adipose stem cells (hASCs), in a de novo fashion, is described. By applying a thermally labile retro-Diels-Alder caging and linkage chemistry, these miRNAs can be triggered to de-cage serially with discrete control of activation times. The method relies on illumination of the nanoparticles at their resonant wavelengths to generate sufficient local heating and trigger the untethering of the Diels-Alder cycloadduct. Characterization of the photothermal release using fluorophore-tagged miRNA mimics in vitro is carried out with fluorescence measurements, second harmonic generation, and confocal imaging. Osteogenesis of hASCs from the sequential co-delivery of miR-21 and miR-148b mimics is assessed using xylenol orange and alizarin red staining of deposited minerals, and quantitative polymerase chain reaction for gene expression of osteogenic markers. The results demonstrate that sequential miRNA mimic activation results in upregulation of osteogenic markers and mineralization relative to miR-148b alone, and co-activation of miR-148b and miR-21 at the same time.
Collapse
Affiliation(s)
- Mohammad Abu-Laban
- The Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Prakash Hamal
- The Department of Chemistry, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Julien H Arrizabalaga
- The Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Anoosha Forghani
- The Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Asela S Dikkumbura
- The Department of Chemistry, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Raju R Kumal
- John and Willie Leone Family Department of Energy and Mineral Engineering, Pennsylvania State University, University Park, PA, 16802, USA
| | - Louis H Haber
- The Department of Chemistry, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Daniel J Hayes
- The Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
- Materials Research Institute, Millennium Science Complex, Pennsylvania State University, University Park, PA, 16802, USA
- The Huck Institute of the Life Sciences, Millennium Science Complex, Pennsylvania State University, University Park, PA, 16802, USA
| |
Collapse
|
19
|
Singh G, Sridharan D, Khan M, Seshagiri PB. Mouse embryonic stem cell-derived cardiomyocytes cease to beat following exposure to monochromatic light: association with increased ROS and loss of calcium transients. Am J Physiol Cell Physiol 2019; 317:C725-C736. [PMID: 31314584 DOI: 10.1152/ajpcell.00188.2019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We earlier established the mouse embryonic stem (ES) cell "GS-2" line expressing enhanced green fluorescent protein (EGFP) and have been routinely using it to understand the molecular regulation of differentiation into cardiomyocytes. During such studies, we made a serendipitous discovery that functional cardiomyocytes derived from ES cells stopped beating when exposed to blue light. We observed a gradual cessation of contractility within a few minutes, regardless of wavelength (nm) ranges tested: blue (~420-495), green (~510-575), and red (~600-700), with green light manifesting the strongest impact. Following shifting of cultures back into the incubator (darkness), cardiac clusters regained beatings within a few hours. The observed light-induced contractility-inhibition effect was intrinsic to cardiomyocytes and not due to interference from other cell types. Also, this was not influenced by any physicochemical parameters or intracellular EGFP expression. Interestingly, the light-induced cardiomyocyte contractility inhibition was accompanied by increased intracellular reactive oxygen species (ROS), which could be abolished in the presence of N-acetylcysteine (ROS quencher). Besides, the increased intracardiomyocyte ROS levels were incidental to the inhibition of calcium transients and suppression of mitochondrial activity, both being essential for sarcomere function. To the best of our knowledge, ours is the first report to demonstrate the monochromatic light-mediated inhibition of contractions of cardiomyocytes with no apparent loss of cell viability and contractility. Our findings have implications in cardiac cell biology context in terms of 1) mechanistic insights into light impact on cardiomyocyte contraction, 2) potential use in laser beam-guided (cardiac) microsurgery, photo-optics-dependent medical diagnostics, 3) transient cessation of hearts during coronary artery bypass grafting, and 4) functional preservation of hearts for transplantation.
Collapse
Affiliation(s)
- Gurbind Singh
- Centre for Stem Cell Research, Christian Medical College Campus, Bagayam, Vellore, India
| | - Divya Sridharan
- Department of Molecular Reproduction, Development, and Genetics, Indian Institute of Science, Bangalore, India
| | - Mahmood Khan
- Department of Emergency Medicine, Wexner Medical Centre, Ohio State University, Columbus, Ohio
| | - Polani B Seshagiri
- Department of Molecular Reproduction, Development, and Genetics, Indian Institute of Science, Bangalore, India
| |
Collapse
|
20
|
Blue Light Increases Neuronal Activity-Regulated Gene Expression in the Absence of Optogenetic Proteins. eNeuro 2019; 6:ENEURO.0085-19.2019. [PMID: 31444226 PMCID: PMC6751372 DOI: 10.1523/eneuro.0085-19.2019] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 08/01/2019] [Accepted: 08/15/2019] [Indexed: 01/05/2023] Open
Abstract
Optogenetics is widely used to control diverse cellular functions with light, requiring experimenters to expose cells to bright light. Because extended exposure to visible light can be toxic to cells, it is important to characterize the effects of light stimulation on cellular function in the absence of optogenetic proteins. Here we exposed mouse cortical cultures with no exogenous optogenetic proteins to several hours of flashing blue, red, or green light. We found that exposing these cultures to as short as 1 h of blue light, but not red or green light, results in an increase in the expression of neuronal activity-regulated genes. Our findings suggest that blue light stimulation is ill suited to long-term optogenetic experiments, especially those that measure transcription, and they emphasize the importance of performing light-only control experiments in samples without optogenetic proteins.
Collapse
|
21
|
Tao JX, Zhou WC, Zhu XG. Mitochondria as Potential Targets and Initiators of the Blue Light Hazard to the Retina. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:6435364. [PMID: 31531186 PMCID: PMC6721470 DOI: 10.1155/2019/6435364] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Revised: 06/18/2019] [Accepted: 07/25/2019] [Indexed: 12/20/2022]
Abstract
Commercially available white light-emitting diodes (LEDs) have an intense emission in the range of blue light, which has raised a range of public concerns about their potential risks as retinal hazards. Distinct from other visible light components, blue light is characterized by short wavelength, high energy, and strong penetration that can reach the retina with relatively little loss in damage potential. Mitochondria are abundant in retinal tissues, giving them relatively high access to blue light, and chromophores, which are enriched in the retina, have many mitochondria able to absorb blue light and induce photochemical effects. Therefore, excessive exposure of the retina to blue light tends to cause ROS accumulation and oxidative stress, which affect the structure and function of the retinal mitochondria and trigger mitochondria-involved death signaling pathways. In this review, we highlight the essential roles of mitochondria in blue light-induced photochemical damage and programmed cell death in the retina, indicate directions for future research and preventive targets in terms of the blue light hazard to the retina, and suggest applying LED devices in a rational way to prevent the blue light hazard.
Collapse
Affiliation(s)
- Jin-Xin Tao
- Department of Neurosurgery, The Second Affiliated Hospital of Nanchang University, Nanchang 330006, China
- Department of Clinical Medicine, The Second Clinical Medical College, Nanchang University, Nanchang 330006, China
| | - Wen-Chuan Zhou
- Department of Neurosurgery, The Second Affiliated Hospital of Nanchang University, Nanchang 330006, China
- Department of Clinical Medicine, The Second Clinical Medical College, Nanchang University, Nanchang 330006, China
| | - Xin-Gen Zhu
- Department of Neurosurgery, The Second Affiliated Hospital of Nanchang University, Nanchang 330006, China
| |
Collapse
|
22
|
Yang Z, Loh KY, Chu YT, Feng R, Satyavolu NSR, Xiong M, Nakamata Huynh SM, Hwang K, Li L, Xing H, Zhang X, Chemla YR, Gruebele M, Lu Y. Optical Control of Metal Ion Probes in Cells and Zebrafish Using Highly Selective DNAzymes Conjugated to Upconversion Nanoparticles. J Am Chem Soc 2018; 140:17656-17665. [PMID: 30427666 DOI: 10.1021/jacs.8b09867] [Citation(s) in RCA: 176] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Spatial and temporal distributions of metal ions in vitro and in vivo are crucial in our understanding of the roles of metal ions in biological systems, and yet there is a very limited number of methods to probe metal ions with high space and time resolution, especially in vivo. To overcome this limitation, we report a Zn2+-specific near-infrared (NIR) DNAzyme nanoprobe for real-time metal ion tracking with spatiotemporal control in early embryos and larvae of zebrafish. By conjugating photocaged DNAzymes onto lanthanide-doped upconversion nanoparticles (UCNPs), we have achieved upconversion of a deep tissue penetrating NIR 980 nm light into 365 nm emission. The UV photon then efficiently photodecages a substrate strand containing a nitrobenzyl group at the 2'-OH of adenosine ribonucleotide, allowing enzymatic cleavage by a complementary DNA strand containing a Zn2+-selective DNAzyme. The product containing a visible FAM fluorophore that is initially quenched by BHQ1 and Dabcyl quenchers is released after cleavage, resulting in higher fluorescent signals. The DNAzyme-UCNP probe enables Zn2+ sensing by exciting in the NIR biological imaging window in both living cells and zebrafish embryos and detecting in the visible region. In this study, we introduce a platform that can be used to understand the Zn2+ distribution with spatiotemporal control, thereby giving insights into the dynamical Zn2+ ion distribution in intracellular and in vivo models.
Collapse
Affiliation(s)
| | | | | | | | | | - Mengyi Xiong
- Institute of Chemical Biology and Nanomedicine, College of Chemistry and Chemical Engineering , Hunan University , Changsha , Hunan 410082 , China
| | | | | | - Lele Li
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety and CAS Center for Excellence in Nanoscience , National Center for Nanoscience and Technology , Beijing 100190 , China
| | - Hang Xing
- Institute of Chemical Biology and Nanomedicine, College of Chemistry and Chemical Engineering , Hunan University , Changsha , Hunan 410082 , China
| | - Xiaobing Zhang
- Institute of Chemical Biology and Nanomedicine, College of Chemistry and Chemical Engineering , Hunan University , Changsha , Hunan 410082 , China
| | | | | | | |
Collapse
|
23
|
Ribeiro OK, Zentmyer GA, Erwin DC. The Influence of Qualitative and Quantitative Radiation on Reproduction and Spore Germination of Four Phytophthora Species. Mycologia 2018. [DOI: 10.1080/00275514.1976.12020005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- O. K. Ribeiro
- Department of Plant Pathology, University of California, Riverside, California 92502
| | - G. A. Zentmyer
- Department of Plant Pathology, University of California, Riverside, California 92502
| | - D. C. Erwin
- Department of Plant Pathology, University of California, Riverside, California 92502
| |
Collapse
|
24
|
Kolesky DB, Homan KA, Skylar-Scott M, Lewis JA. In Vitro Human Tissues via Multi-material 3-D Bioprinting. Altern Lab Anim 2018; 46:209-215. [DOI: 10.1177/026119291804600404] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
This paper highlights the foundational research on multi-material 3-D bioprinting of human tissues, for which the Lewis Bioprinting team at Harvard University was awarded the 2017 Lush Science Prize. The team's bioprinting platform enables the rapid fabrication of 3-D human tissues that contain all of the essential components found in their in vivo counterparts: cells, vasculature (or other tubular features) and extracellular matrix. The printed 3-D tissues are housed within a customised perfusion system and are subjected to controlled microphysiological environments over long durations (days to months). As exemplars, the team created a thick, stem cell-laden vascularised tissue that was controllably differentiated toward an osteogenic lineage in situ, and a 3-D kidney tissue that recapitulated the proximal tubule, a sub-unit of the nephron responsible for solute reabsorption. This highly versatile platform for manufacturing 3D human tissue in vitro opens new avenues for replacing animal models used to develop next-generation therapies, test toxicity and study disease pathology.
Collapse
Affiliation(s)
- David B. Kolesky
- Wyss Institute for Biologically Inspired Engineering and Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - Kimberly A. Homan
- Wyss Institute for Biologically Inspired Engineering and Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - Mark Skylar-Scott
- Wyss Institute for Biologically Inspired Engineering and Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - Jennifer A. Lewis
- Wyss Institute for Biologically Inspired Engineering and Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| |
Collapse
|
25
|
Neutsch L, Kroll P, Brunner M, Pansy A, Kovar M, Herwig C, Klein T. Media photo-degradation in pharmaceutical biotechnology - impact of ambient light on media quality, cell physiology, and IgG production in CHO cultures. JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY (OXFORD, OXFORDSHIRE : 1986) 2018; 93:2141-2151. [PMID: 30069078 PMCID: PMC6055871 DOI: 10.1002/jctb.5643] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2017] [Revised: 02/22/2018] [Accepted: 03/24/2018] [Indexed: 05/13/2023]
Abstract
BACKGROUND Many vital components in bioprocess media are prone to photo-conversion or photo-degradation upon exposure to ambient light, with severe negative consequences for biomass yield and overall productivity. However, there is only limited awareness of light irradiation as a potential risk factor when working in transparent glass bioreactors, storage vessels or disposable bag systems. The chemical complexity of most media renders a root-cause analysis difficult. This study investigated in a novel, holistic approach how light-induced changes in media composition relate to alterations in radical burden, cell physiology, morphology, and product formation in industrial Chinese hamster ovary (CHO) bioprocesses. RESULTS Two media formulations from proprietary and commercial sources were tested in a pre-hoc light exposure scenario prior to cultivation. Using fluorescence excitation/emission (EEM) matrix spectroscopy, a photo-sensitization of riboflavin was identified as a likely cause for drastically decreased IgG titers (up to -80%) and specific growth rates (-50% to -90%). Up to three-fold higher radical levels were observed in photo-degraded medium. On the biological side, this resulted in significant changes in cell morphology and aberrations in the normal IgG biosynthesis/secretion pathway. CONCLUSION These findings clearly illustrate the underrated impact of room light after only short periods of exposure, occurring accidentally or knowingly during bioprocess development and scale- up. The detrimental effects, which may share a common mechanistic cause at the molecular level, correlate well with changes in spectroscopic properties. This offers new perspectives for online monitoring concepts, and improved detectability of such effects in future. © 2018 The Authors. Journal of Chemical Technology & Biotechnology published by JohnWiley & Sons Ltd on behalf of Society of Chemical Industry.
Collapse
Affiliation(s)
- Lukas Neutsch
- Research Division Biochemical EngineeringVienna University of Technology, Institute of Chemical EngineeringViennaAustria
| | - Paul Kroll
- Research Division Biochemical EngineeringVienna University of Technology, Institute of Chemical EngineeringViennaAustria
- CD Laboratory on Mechanistic and Physiological Methods for Improved BioprocessesVienna University of TechnologyViennaAustria
| | - Matthias Brunner
- Research Division Biochemical EngineeringVienna University of Technology, Institute of Chemical EngineeringViennaAustria
- CD Laboratory on Mechanistic and Physiological Methods for Improved BioprocessesVienna University of TechnologyViennaAustria
| | - Alexander Pansy
- Research Division Biochemical EngineeringVienna University of Technology, Institute of Chemical EngineeringViennaAustria
- CD Laboratory on Mechanistic and Physiological Methods for Improved BioprocessesVienna University of TechnologyViennaAustria
| | - Michael Kovar
- Research Division Biochemical EngineeringVienna University of Technology, Institute of Chemical EngineeringViennaAustria
- CD Laboratory on Mechanistic and Physiological Methods for Improved BioprocessesVienna University of TechnologyViennaAustria
| | - Christoph Herwig
- Research Division Biochemical EngineeringVienna University of Technology, Institute of Chemical EngineeringViennaAustria
- CD Laboratory on Mechanistic and Physiological Methods for Improved BioprocessesVienna University of TechnologyViennaAustria
| | - Tobias Klein
- Research Division Biochemical EngineeringVienna University of Technology, Institute of Chemical EngineeringViennaAustria
- CD Laboratory on Mechanistic and Physiological Methods for Improved BioprocessesVienna University of TechnologyViennaAustria
| |
Collapse
|
26
|
Nakashima Y, Ohta S, Wolf AM. Blue light-induced oxidative stress in live skin. Free Radic Biol Med 2017; 108:300-310. [PMID: 28315451 DOI: 10.1016/j.freeradbiomed.2017.03.010] [Citation(s) in RCA: 121] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 03/02/2017] [Accepted: 03/11/2017] [Indexed: 11/16/2022]
Abstract
Skin damage from exposure to sunlight induces aging-like changes in appearance and is attributed to the ultraviolet (UV) component of light. Photosensitized production of reactive oxygen species (ROS) by UVA light is widely accepted to contribute to skin damage and carcinogenesis, but visible light is thought not to do so. Using mice expressing redox-sensitive GFP to detect ROS, blue light could produce oxidative stress in live skin. Blue light induced oxidative stress preferentially in mitochondria, but green, red, far red or infrared light did not. Blue light-induced oxidative stress was also detected in cultured human keratinocytes, but the per photon efficacy was only 25% of UVA in human keratinocyte mitochondria, compared to 68% of UVA in mouse skin. Skin autofluorescence was reduced by blue light, suggesting flavins are the photosensitizer. Exposing human skin to the blue light contained in sunlight depressed flavin autofluorescence, demonstrating that the visible component of sunlight has a physiologically significant effect on human skin. The ROS produced by blue light is probably superoxide, but not singlet oxygen. These results suggest that blue light contributes to skin aging similar to UVA.
Collapse
Affiliation(s)
- Yuya Nakashima
- Department of Biochemistry and Cell Biology, Institute of Development and Aging Sciences, Graduate School of Medicine, Nippon Medical School, 1-396 Kosugi, Nakahara-ku, Kawasaki, Kanagawa 211-8533, Japan
| | - Shigeo Ohta
- Department of Biochemistry and Cell Biology, Institute of Development and Aging Sciences, Graduate School of Medicine, Nippon Medical School, 1-396 Kosugi, Nakahara-ku, Kawasaki, Kanagawa 211-8533, Japan
| | - Alexander M Wolf
- Department of Biochemistry and Cell Biology, Institute of Development and Aging Sciences, Graduate School of Medicine, Nippon Medical School, 1-396 Kosugi, Nakahara-ku, Kawasaki, Kanagawa 211-8533, Japan.
| |
Collapse
|
27
|
Buckley K, Ryder AG. Applications of Raman Spectroscopy in Biopharmaceutical Manufacturing: A Short Review. APPLIED SPECTROSCOPY 2017; 71:1085-1116. [PMID: 28534676 DOI: 10.1177/0003702817703270] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The production of active pharmaceutical ingredients (APIs) is currently undergoing its biggest transformation in a century. The changes are based on the rapid and dramatic introduction of protein- and macromolecule-based drugs (collectively known as biopharmaceuticals) and can be traced back to the huge investment in biomedical science (in particular in genomics and proteomics) that has been ongoing since the 1970s. Biopharmaceuticals (or biologics) are manufactured using biological-expression systems (such as mammalian, bacterial, insect cells, etc.) and have spawned a large (>€35 billion sales annually in Europe) and growing biopharmaceutical industry (BioPharma). The structural and chemical complexity of biologics, combined with the intricacy of cell-based manufacturing, imposes a huge analytical burden to correctly characterize and quantify both processes (upstream) and products (downstream). In small molecule manufacturing, advances in analytical and computational methods have been extensively exploited to generate process analytical technologies (PAT) that are now used for routine process control, leading to more efficient processes and safer medicines. In the analytical domain, biologic manufacturing is considerably behind and there is both a huge scope and need to produce relevant PAT tools with which to better control processes, and better characterize product macromolecules. Raman spectroscopy, a vibrational spectroscopy with a number of useful properties (nondestructive, non-contact, robustness) has significant potential advantages in BioPharma. Key among them are intrinsically high molecular specificity, the ability to measure in water, the requirement for minimal (or no) sample pre-treatment, the flexibility of sampling configurations, and suitability for automation. Here, we review and discuss a representative selection of the more important Raman applications in BioPharma (with particular emphasis on mammalian cell culture). The review shows that the properties of Raman have been successfully exploited to deliver unique and useful analytical solutions, particularly for online process monitoring. However, it also shows that its inherent susceptibility to fluorescence interference and the weakness of the Raman effect mean that it can never be a panacea. In particular, Raman-based methods are intrinsically limited by the chemical complexity and wide analyte-concentration-profiles of cell culture media/bioprocessing broths which limit their use for quantitative analysis. Nevertheless, with appropriate foreknowledge of these limitations and good experimental design, robust analytical methods can be produced. In addition, new technological developments such as time-resolved detectors, advanced lasers, and plasmonics offer potential of new Raman-based methods to resolve existing limitations and/or provide new analytical insights.
Collapse
Affiliation(s)
- Kevin Buckley
- Nanoscale Biophotonics Laboratory, School of Chemistry, National University of Ireland - Galway, Galway, Ireland
| | - Alan G Ryder
- Nanoscale Biophotonics Laboratory, School of Chemistry, National University of Ireland - Galway, Galway, Ireland
| |
Collapse
|
28
|
Yamada K, Ishiyama S, Onizuka K, Nagatsugi F. Synthesis and properties of cross-linkable DNA duplex using 4-amino-2-oxo-6-vinyl-1,3,5-triazine. Tetrahedron 2017. [DOI: 10.1016/j.tet.2017.01.043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
|
29
|
Abstract
The advancement of tissue and, ultimately, organ engineering requires the ability to pattern human tissues composed of cells, extracellular matrix, and vasculature with controlled microenvironments that can be sustained over prolonged time periods. To date, bioprinting methods have yielded thin tissues that only survive for short durations. To improve their physiological relevance, we report a method for bioprinting 3D cell-laden, vascularized tissues that exceed 1 cm in thickness and can be perfused on chip for long time periods (>6 wk). Specifically, we integrate parenchyma, stroma, and endothelium into a single thick tissue by coprinting multiple inks composed of human mesenchymal stem cells (hMSCs) and human neonatal dermal fibroblasts (hNDFs) within a customized extracellular matrix alongside embedded vasculature, which is subsequently lined with human umbilical vein endothelial cells (HUVECs). These thick vascularized tissues are actively perfused with growth factors to differentiate hMSCs toward an osteogenic lineage in situ. This longitudinal study of emergent biological phenomena in complex microenvironments represents a foundational step in human tissue generation.
Collapse
|
30
|
Zheng B, Su L, Pan H, Hou B, Zhang Y, Zhou F, Wu X, Gong X, Wang H, Chang J. NIR-Remote Selected Activation Gene Expression in Living Cells by Upconverting Microrods. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2016; 28:707-714. [PMID: 26619378 DOI: 10.1002/adma.201503961] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 10/20/2015] [Indexed: 06/05/2023]
Abstract
An NIR-controlled gene expression system based on upconverting rods (UCRs) is demonstrated. The UCRs can harvest the "biocompatible" NIR light and convert it into local UV light, resulting in cleavage of the photosensitive molecule (4-(hydroxymethyl)-3-nitrobenzoic acid, ONA) and on-demand release of gene carriers, thus realizing target gene expression at high spatial and temporal resolutions.
Collapse
Affiliation(s)
- Bin Zheng
- School of Life Sciences, Tianjin University, Tianjin Engineering Center of Micro-Nano Biomaterials and Detection-Treatment Technology, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), 92 Weijin Road, Nankai District, Tianjin, 300072, P.R. China
| | - Lin Su
- School of Materials Science and Engineering, Tianjin University, 92 Weijin Road, Nankai District, Tianjin, 300072, P.R. China
| | - Huizhuo Pan
- School of Life Sciences, Tianjin University, Tianjin Engineering Center of Micro-Nano Biomaterials and Detection-Treatment Technology, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), 92 Weijin Road, Nankai District, Tianjin, 300072, P.R. China
| | - Beibei Hou
- School of Materials Science and Engineering, Tianjin University, 92 Weijin Road, Nankai District, Tianjin, 300072, P.R. China
| | - Ying Zhang
- School of Life Sciences, Tianjin University, Tianjin Engineering Center of Micro-Nano Biomaterials and Detection-Treatment Technology, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), 92 Weijin Road, Nankai District, Tianjin, 300072, P.R. China
| | - Fang Zhou
- School of Materials Science and Engineering, Tianjin University, 92 Weijin Road, Nankai District, Tianjin, 300072, P.R. China
| | - Xiaoli Wu
- School of Life Sciences, Tianjin University, Tianjin Engineering Center of Micro-Nano Biomaterials and Detection-Treatment Technology, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), 92 Weijin Road, Nankai District, Tianjin, 300072, P.R. China
| | - Xiaoqun Gong
- School of Life Sciences, Tianjin University, Tianjin Engineering Center of Micro-Nano Biomaterials and Detection-Treatment Technology, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), 92 Weijin Road, Nankai District, Tianjin, 300072, P.R. China
| | - Hanjie Wang
- School of Life Sciences, Tianjin University, Tianjin Engineering Center of Micro-Nano Biomaterials and Detection-Treatment Technology, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), 92 Weijin Road, Nankai District, Tianjin, 300072, P.R. China
| | - Jin Chang
- School of Life Sciences, Tianjin University, Tianjin Engineering Center of Micro-Nano Biomaterials and Detection-Treatment Technology, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), 92 Weijin Road, Nankai District, Tianjin, 300072, P.R. China
| |
Collapse
|
31
|
McElearney K, Ali A, Gilbert A, Kshirsagar R, Zang L. Tryptophan oxidation catabolite,N-formylkynurenine, in photo degraded cell culture medium results in reduced cell culture performance. Biotechnol Prog 2015; 32:74-82. [DOI: 10.1002/btpr.2198] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 10/24/2015] [Indexed: 12/14/2022]
Affiliation(s)
- Kyle McElearney
- Cell Culture Development, Biogen; 225 Binney Street Cambridge MA 02142
| | - Amr Ali
- Cell Culture Development, Biogen; 225 Binney Street Cambridge MA 02142
| | - Alan Gilbert
- Cell Culture Development, Biogen; 225 Binney Street Cambridge MA 02142
| | - Rashmi Kshirsagar
- Cell Culture Development, Biogen; 225 Binney Street Cambridge MA 02142
| | - Li Zang
- Analytical Development, Biogen; 225 Binney Street Cambridge MA 02142
| |
Collapse
|
32
|
Risović D, Maver-Bišćanin M, Mravak-Stipetić M, Bukovski S, Bišćanin A. Quantitative investigation of efficiency of ultraviolet and visible light in eradication of Candida albicans in vitro. Photomed Laser Surg 2015; 32:232-9. [PMID: 24697585 DOI: 10.1089/pho.2013.3691] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
OBJECTIVE The aim of this study was to quantitatively investigate the efficiency of the ultraviolet (UV) and visible light in eradication of Candida albicans in vitro; in particular, to determine, for selected wavelengths, the specific eradication coefficients and thresholds in terms of energy density levels required to effect 3.0log10 and 4.0log10 reduction. BACKGROUND DATA Oral candidosis is the most common infection of the oral cavity and is caused by Candida species. The widespread use of topical and systemic antifungal agents as conventional treatment for oral candidosis has resulted in the development of resistance in C. albicans. Therefore, it has become necessary to develop alternative therapies for the treatment of oral candidosis. METHODS C. albicans ATCC(®) 90028(™) was irradiated with 254 nm, 365 nm, 406 nm, 420 nm, and broadband Xe spectrum. For each wavelength, a fit of experimental data (survival fraction vs. applied energy density) with an exponential decay function enabled estimation of the specific eradication coefficients and thresholds. RESULTS Based on estimated specific efficiencies (Δ) and eradication thresholds (ET) of the investigated wavelengths, the ranking in eradication efficiency of C. albicans (most to least effective) is: 254 nm (Δ=6.1 mJ/cm(-2), ET99.99=56 mJ/cm(-2)), broadband Xe spectrum (Δ=27.7 mJ/cm(-2), ET99.99=255 mJ/cm(-2)), 365 nm (Δ=4.3 J/cm(-2), ET99.99=39 J/cm(-2)), 420 nm (Δ=0.65 J/cm(-2), ET99.99=6 J/cm(-2)), and 406 nm (Δ=11.4 J/cm(-2), ET99.99=104 J/cm(-2)). CONCLUSIONS The results provide insight into the wavelength-dependent dynamics of eradication of C. albicans. For each investigated wavelength, the eradication coefficient and corresponding eradication threshold were estimated. The observed different eradication efficiencies are consequence of different spectrally dependent inactivation mechanisms. The established methodology enables unambiguous quantitative comparison of eradication efficiencies of optical radiation and selection of most effective wavelengths for clinical and therapeutic use.
Collapse
Affiliation(s)
- Dubravko Risović
- 1 Molecular Physics Laboratory, Ruđer Bošković Institute , Bijenicka, Zagreb, Croatia
| | | | | | | | | |
Collapse
|
33
|
Griepenburg JC, Rapp TL, Carroll PJ, Eberwine J, Dmochowski IJ. Ruthenium-Caged Antisense Morpholinos for Regulating Gene Expression in Zebrafish Embryos. Chem Sci 2015; 6:2342-2346. [PMID: 26023327 PMCID: PMC4443914 DOI: 10.1039/c4sc03990d] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 01/29/2015] [Indexed: 11/25/2022] Open
Abstract
Photochemical approaches afford high spatiotemporal control over molecular structure and function, for broad applications in materials and biological science. Here, we present the first example of a visible light responsive ruthenium-based photolinker, Ru(bipyridine)2(3-ethynylpyridine)2 (RuBEP), which was reacted stoichiometrically with a 25mer DNA or morpholino (MO) oligonucleotide functionalized with 3' and 5' terminal azides, via Cu(I)-mediated [3+2] Huisgen cycloaddition reactions. RuBEP-caged circular morpholinos (Ru-MOs) targeting two early developmental zebrafish genes, chordin and notail, were synthesized and tested in vivo. One-cell-stage zebrafish embryos microinjected with Ru-MO and incubated in the dark for 24 h developed normally, consistent with caging, whereas irradiation at 450 nm dissociated one 3-ethynylpyridine ligand (ϕ = 0.33) and uncaged the MO to achieve gene knockdown. As demonstrated, Ru photolinkers provide a versatile method for controlling structure and function of biopolymers.
Collapse
Affiliation(s)
- Julianne C. Griepenburg
- Department of Chemistry , University of Pennsylvania , 231 South 34th Street , Philadelphia , Pennsylvania 19104 , USA .
| | - Teresa L. Rapp
- Department of Chemistry , University of Pennsylvania , 231 South 34th Street , Philadelphia , Pennsylvania 19104 , USA .
| | - Patrick J. Carroll
- Department of Chemistry , University of Pennsylvania , 231 South 34th Street , Philadelphia , Pennsylvania 19104 , USA .
| | - James Eberwine
- Department of Systems Pharmacology and Experimental Therapeutics , Perelman School of Medicine , University of Pennsylvania , 37 John Morgan Building, 3620 Hamilton Walk , Philadelphia , Pennsylvania 19104 , USA
| | - Ivan J. Dmochowski
- Department of Chemistry , University of Pennsylvania , 231 South 34th Street , Philadelphia , Pennsylvania 19104 , USA .
| |
Collapse
|
34
|
Calvet A, Ryder AG. Monitoring cell culture media degradation using surface enhanced Raman scattering (SERS) spectroscopy. Anal Chim Acta 2014; 840:58-67. [DOI: 10.1016/j.aca.2014.06.021] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 05/30/2014] [Accepted: 06/02/2014] [Indexed: 11/26/2022]
|
35
|
Mallaney M, Wang SH, Sreedhara A. Effect of ambient light on monoclonal antibody product quality during small-scale mammalian cell culture process in clear glass bioreactors. Biotechnol Prog 2014; 30:562-70. [PMID: 24777986 DOI: 10.1002/btpr.1920] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Revised: 04/22/2014] [Indexed: 12/14/2022]
Abstract
During a small-scale cell culture process producing a monoclonal antibody, a larger than expected difference was observed in the charge variants profile of the harvested cell culture fluid (HCCF) between the 2 L and larger scales (e.g., 400 L and 12 kL). Small-scale studies performed at the 2 L scale consistently showed an increase in acidic species when compared with the material made at larger scale. Since the 2 L bioreactors were made of clear transparent glass while the larger scale reactors are made of stainless steel, the effect of ambient laboratory light on cell culture process in 2 L bioreactors as well as handling the HCCF was carefully evaluated. Photoreactions in the 2 L glass bioreactors including light mediated increase in acidic variants in HCCF and formulation buffers were identified and carefully analyzed. While the acidic variants comprised of a mixture of sialylated, reduced disulfide, crosslinked (nonreducible), glycated, and deamidated forms, an increase in the nonreducible forms, deamidation and Met oxidation was predominantly observed under light stress. The monoclonal antibody produced in glass bioreactors that were protected from light behaved similar to the one produced in the larger scale. Our data clearly indicate that care should be taken when glass bioreactors are used in cell culture studies during monoclonal antibody production.
Collapse
Affiliation(s)
- Mary Mallaney
- Purification Department, Genentech, South San Francisco, CA 94080
| | | | | |
Collapse
|
36
|
Calvet A, Li B, Ryder AG. A rapid fluorescence based method for the quantitative analysis of cell culture media photo-degradation. Anal Chim Acta 2014; 807:111-9. [DOI: 10.1016/j.aca.2013.11.028] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Revised: 10/31/2013] [Accepted: 11/14/2013] [Indexed: 10/26/2022]
|
37
|
Singh R, Tønnesen HH, Kristensen S, Berg K. The influence of Pluronics® on dark cytotoxicity, photocytotoxicity, localization and uptake of curcumin in cancer cells: studies of curcumin and curcuminoids XLIX. Photochem Photobiol Sci 2013; 12:559-75. [PMID: 23108412 DOI: 10.1039/c2pp25249j] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In order to apply curcumin as a photosensitizer in photodynamic therapy (PDT) one needs a formulation that can solubilize and stabilize the compound. Pluronics® (Pluronic) are reported to both solubilize and stabilize curcumin against hydrolytic degradation. The aim of the present work was therefore to investigate the influence of Pluronic formulation on the photocytotoxicity of curcumin. Interactions between curcumin and Pluronics were investigated by fluorescence emission and absorption spectroscopy. Cell survival was measured with the MTT assay. The location of curcumin in the cells was investigated with fluorescence microscopy, and the cellular uptake was measured with fluorescence emission spectroscopy. Pluronics P123 and F127 in contrast to Pluronic P85 and PEG 400 may solubilize curcumin under non-cytotoxic conditions. An inverse relationship between the concentration of Pluronic and the photocytotoxicity of curcumin was observed. Curcumin could rapidly translocate across the cell membrane by passive diffusion. The fluorescence from curcumin in the cells (in the cytoplasm) after 1 hour of incubation was lowered by the presence of Pluronics in the formulation. However, the absolute amount of cell-bound curcumin after 1 hour of incubation was independent of the presence of Pluronics. Curcumin was bound more strongly to cells when incubated with formulations without Pluronics compared to cells incubated with curcumin formulations with Pluronics. Incubation of WiDr cells with curcumin for 6 hours resulted in lysosomal accumulation of curcumin independent of the presence of Pluronics. Lysosomally located curcumin could not be observed in HT1080 cells after 6 hours of incubation. The Pluronics P123 and F127 were found to be suitable for solubilizing and stabilizing curcumin, but inhibited photocytotoxic effects of curcumin unless the Pluronic concentration during treatment of the cells was less than 5-10× above the critical micellar concentration.
Collapse
Affiliation(s)
- Ravinder Singh
- School of Pharmacy, Department of Pharmaceutics, University of Oslo, P.O. Box 1068, Blindern, 0316 Oslo, Norway.
| | | | | | | |
Collapse
|
38
|
Abstract
In oviparous animals, the egg hatches outside of the body and is exposed to light; in some cases throughout the development of the fetus. In mammals, fertilization and the growth of embryos in vivo occurs in the dark but in human IVF, these embryos are exposed to variable light sources and intensities. Light can affect embryonic development in some species via either a direct toxic effect on the embryo, or indirectly via photo-oxidation of components in the media or oil. Although data regarding the effect of light on human embryos is lacking, it is prudent to take appropriate steps to minimize the potential harmful effects of both ambient and microscopic light on embryos.
Collapse
Affiliation(s)
- Kimball O Pomeroy
- Florida Institute for Reproductive Medicine, Miami, FL, 33143, USA and Arizona Reproductive Medicine Specialists, Phoenix, AZ, 85016, USA
| | - Michael L. Reed
- Center for Reproductive Medicine of New Mexico, Albuquerque, NM, 87106, USA
| |
Collapse
|
39
|
del Olmo-Aguado S, Manso AG, Osborne NN. Light Might Directly Affect Retinal Ganglion Cell Mitochondria to Potentially Influence Function†. Photochem Photobiol 2012; 88:1346-55. [DOI: 10.1111/j.1751-1097.2012.01120.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
|
40
|
Zang L, Frenkel R, Simeone J, Lanan M, Byers M, Lyubarskaya Y. Metabolomics Profiling of Cell Culture Media Leading to the Identification of Riboflavin Photosensitized Degradation of Tryptophan Causing Slow Growth in Cell Culture. Anal Chem 2011; 83:5422-30. [DOI: 10.1021/ac2009492] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Li Zang
- Analytical Development Department and ‡Manufacturing Sciences Department, BiogenIdec, Cambridge, Massachusetts 02142, United States
| | - Ruth Frenkel
- Analytical Development Department and ‡Manufacturing Sciences Department, BiogenIdec, Cambridge, Massachusetts 02142, United States
| | - Jeffrey Simeone
- Analytical Development Department and ‡Manufacturing Sciences Department, BiogenIdec, Cambridge, Massachusetts 02142, United States
| | - Maureen Lanan
- Analytical Development Department and ‡Manufacturing Sciences Department, BiogenIdec, Cambridge, Massachusetts 02142, United States
| | - Mark Byers
- Analytical Development Department and ‡Manufacturing Sciences Department, BiogenIdec, Cambridge, Massachusetts 02142, United States
| | - Yelena Lyubarskaya
- Analytical Development Department and ‡Manufacturing Sciences Department, BiogenIdec, Cambridge, Massachusetts 02142, United States
| |
Collapse
|
41
|
Allahverdiyev AM, Koc RC, Ates SC, Bagirova M, Elcicek S, Oztel ON. Leishmania tropica: the effect of darkness and light on biological activities in vitro. Exp Parasitol 2011; 128:318-23. [PMID: 21510933 DOI: 10.1016/j.exppara.2011.04.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2010] [Revised: 04/01/2011] [Accepted: 04/05/2011] [Indexed: 11/27/2022]
Abstract
Leishmania parasites can be exposed to effects of light in their vectors and hosts, at various periods. However, there is no information about the effects of light on Leishmania parasites. The aim of this study is to investigate the effects of light on various cell parameters of Leishmania tropica, in vitro. All experiments were conducted on L. tropica promastigotes and amastigote-macrophage cultures, using flow cytometric analysis, MTT and phenol-sulfuric acid assay, DAPI and Giemsa. The results showed that the morphology of parasites has changed; the cell cycle has been affected and this caused parasites to remain at G0/G1 phase. Furthermore the proliferation, infectivity, glucose consumption and mitochondrial dehydrogenase activities of parasites were decreased. Thus, for the first time, in this study, the effects of light on biological activities of Leishmania parasites were shown. These new information about parasites' biology, would be very important to investigate the effects of light on the parasites in infected vectors and hosts.
Collapse
Affiliation(s)
- Adil M Allahverdiyev
- Yildiz Technical University, Department of Bioengineering, 34220 Istanbul, Turkey.
| | | | | | | | | | | |
Collapse
|
42
|
Olivier D, Douillard S, Lhommeau I, Patrice T. Photodynamic Treatment of Culture Medium Containing Serum Induces Long-Lasting ToxicityIn Vitro. Radiat Res 2009; 172:451-62. [DOI: 10.1667/rr1646.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
43
|
Huvaere K, Olsen K, Skibsted LH. Quenching of Triplet-Excited Flavins by Flavonoids. Structural Assessment of Antioxidative Activity. J Org Chem 2009; 74:7283-93. [DOI: 10.1021/jo901301c] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kevin Huvaere
- Food Chemistry, Department of Food Science, Faculty of Life Sciences, University of Copenhagen, Rolighedsvej 30, DK-1958 Frederiksberg C, Denmark
| | - Karsten Olsen
- Food Chemistry, Department of Food Science, Faculty of Life Sciences, University of Copenhagen, Rolighedsvej 30, DK-1958 Frederiksberg C, Denmark
| | - Leif H. Skibsted
- Food Chemistry, Department of Food Science, Faculty of Life Sciences, University of Copenhagen, Rolighedsvej 30, DK-1958 Frederiksberg C, Denmark
| |
Collapse
|
44
|
Pritchard DJ. Transdifferentiation and survival of neural retina cells in relation to illumination. ACTA ACUST UNITED AC 2009; 4:187-91. [PMID: 6545396 DOI: 10.3109/13816818409006120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Cultures of chicken embryo neural retina cells were exposed to light of different intensities and colours, in order to identify the wavelengths that promote cell degeneration and transdifferentiation into pigment epithelium. Blue and green light caused cell death; blue, green and yellow light enhanced transdifferentiation; red light had no effect. The relevance of these findings to retinal degeneration in man and the possible mediation of rhodopsin, riboflavin and other chromophores are discussed.
Collapse
|
45
|
Babich H, Liebling EJ, Burger RF, Zuckerbraun HL, Schuck AG. Choice of DMEM, formulated with or without pyruvate, plays an important role in assessing the in vitro cytotoxicity of oxidants and prooxidant nutraceuticals. In Vitro Cell Dev Biol Anim 2009; 45:226-33. [DOI: 10.1007/s11626-008-9168-z] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2008] [Accepted: 12/16/2008] [Indexed: 01/23/2023]
|
46
|
Weaver CA, Tuveson RW. BLACKLIGHT AND SHORTWAVE UV SENSITIVITY OF NEUROSPORA CRASSA AS A FUNCTION OF CULTURE AGE. Photochem Photobiol 2008. [DOI: 10.1111/j.1751-1097.1979.tb07836.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
47
|
Girotti AW, Giacomoni PU. Lipid and Protein Damage Provoked by Ultraviolet Radiation: Mechanisms of Indirect Photooxidative Damage. BIOPHYSICAL AND PHYSIOLOGICAL EFFECTS OF SOLAR RADIATION ON HUMAN SKIN 2007. [DOI: 10.1039/9781847557957-00271] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Albert W. Girotti
- Department of Biochemistry Medical College of Wisconsin Milwaukee WI USA
| | | |
Collapse
|
48
|
Stangegaard M, Petronis S, Jørgensen AM, Christensen CBV, Dufva M. A biocompatible micro cell culture chamber (microCCC) for the culturing and on-line monitoring of eukaryote cells. LAB ON A CHIP 2006; 6:1045-51. [PMID: 16874376 DOI: 10.1039/b603379b] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
We have previously shown that a polymeric (PMMA) chip with medium perfusion and integrated heat regulation provides sufficiently precise heat regulation, pH-control and medium exchange to support cell growth for weeks. However, it was unclear how closely the cells cultured in the chip resembled cells cultured in the culture flask. In the current study, gene expression profiles of cells cultured in the chip were compared with gene expression profiles of cells cultured in culture flasks. The results showed that there were only two genes that were differently expressed in cells grown in the cell culture chip compared to cell culture flasks. The cell culture chip could without further modification support cell growth of two other cell lines. Light coming from the microscope lamp during optical recordings of the cells was the only external factor identified, that could have a negative effect on cell survival. Low grade light exposure was however compatible with optical recordings as well as cell viability. These results strongly indicate that a cell culture chip could be constructed that allowed for on-line optical recording of cellular events without affecting the cell culturing condition compared to cell cultured in culture flasks incubated in a dark and CO2 conditioned incubator.
Collapse
Affiliation(s)
- Michael Stangegaard
- Department of Micro and Nanotechnology, Technical University of Denmark, Ørsteds Plads 345 east, DK-2800 Kgs. Lyngby, Denmark
| | | | | | | | | |
Collapse
|
49
|
Merwald H, Klosner G, Kokesch C, Der-Petrossian M, Hönigsmann H, Trautinger F. UVA-induced oxidative damage and cytotoxicity depend on the mode of exposure. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2005; 79:197-207. [PMID: 15896646 DOI: 10.1016/j.jphotobiol.2005.01.002] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2004] [Revised: 01/12/2005] [Accepted: 01/12/2005] [Indexed: 11/24/2022]
Abstract
The reciprocity rule (Bunsen-Roscoe law) states that a photochemical reaction is directly proportional to the total energy dose, irrespective of the dose distribution. In photomedicine the validity of this law is usually taken for granted, although the influence of radiation intensity and dose distribution are largely unknown. We have examined in a tissue culture model the effects of fractionated versus single dose exposure to UV from a metal halide source on survival, DNA synthesis, glutathione, and oxidative membrane damage. Exposure to fractionated UVA was followed by an increased rate of cell death compared to single dose exposure, when intervals between fractions where short (10-120 min). Longer intervals had the opposite effect. Corresponding results were obtained for DNA synthesis (BrdU incorporation). The increased cytotoxicity of dose fractionation with short intervals could not be abrogated by non-enzymatic antioxidants (astaxanthin, ascorbic acid, alpha-tocopherol). Fractionated irradiation with short intervals led to higher degree of depletion of glutathione (GSH) and to enhanced formation of thiobarbituric acid reactive substances (TBARS) in comparison to an identical single dose. Long intervals between fractions induced opposite effects. Taken together, these data indicate that immediately after UVA exposure cells are more sensitive to a further oxidative attack making repeated exposure with short intervals more cytotoxic than continuous single dose UVA. This might have implications also for responses to UVA in vivo and further studies will have to extend these findings to the situation in healthy and diseased human skin.
Collapse
Affiliation(s)
- Helga Merwald
- Division of Special and Environmental Dermatology, Department of Dermatology, Medical University of Vienna, Währinger Gürtel 18-20, A-1090 Vienna, Austria
| | | | | | | | | | | |
Collapse
|
50
|
Keynes RG, Griffiths C, Garthwaite J. Superoxide-dependent consumption of nitric oxide in biological media may confound in vitro experiments. Biochem J 2003; 369:399-406. [PMID: 12366375 PMCID: PMC1223083 DOI: 10.1042/bj20020933] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2002] [Revised: 09/17/2002] [Accepted: 10/04/2002] [Indexed: 11/17/2022]
Abstract
NO functions ubiquitously as a biological messenger but has also been implicated in various pathologies, a role supported by many reports that exogenous or endogenous NO can kill cells in tissue culture. In the course of experiments aimed at examining the toxicity of exogenous NO towards cultured cells, we found that most of the NO delivered using a NONOate (diazeniumdiolate) donor was removed by reaction with the tissue-culture medium. Two NO-consuming ingredients were identified: Hepes buffer and, under laboratory lighting, the vitamin riboflavin. In each case, the loss of NO was reversed by the addition of superoxide dismutase. The effect of Hepes was observed over a range of NONOate concentrations (producing up to 1 microM NO). Furthermore, from measurements of soluble guanylate cyclase activity, Hepes-dependent NO consumption remained significant at the low nanomolar NO concentrations relevant to physiological NO signalling. The combination of Hepes and riboflavin (in the light) acted synergistically to the extent that, instead of a steady-state concentration of about 1 microM being generated, NO was undetectable (<10 nM). Again, the consumption could be inhibited by superoxide dismutase. A scheme is proposed whereby a "vicious cycle" of superoxide radical (O(2)(.-)) formation occurs as a result of oxidation of Hepes to its radical species, fuelled by the subsequent reaction of O(2)(.-) with NO to form peroxynitrite (ONOO(-)). The inadvertent production of ONOO(-) and other reactive species in biological media, or the associated loss of NO, may contribute to the adverse effects, or otherwise, of NO in vitro.
Collapse
Affiliation(s)
- Robert G Keynes
- Wolfson Institute for Biomedical Research, University College London, Cruciform Building, Gower Street, London WC1E 6BT, U.K
| | | | | |
Collapse
|