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Neveu M, Quinn R, Barge LM, Craft KL, German CR, Getty S, Glein C, Parra M, Burton AS, Cary F, Corpolongo A, Fifer L, Gangidine A, Gentry D, Georgiou CD, Haddadin Z, Herbold C, Inaba A, Jordan SF, Kalucha H, Klier P, Knicely K, Li AY, McNally P, Millan M, Naz N, Raj CG, Schroedl P, Timm J, Yang Z. Future of the Search for Life: Workshop Report. Astrobiology 2024; 24:114-129. [PMID: 38227837 DOI: 10.1089/ast.2022.0158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2024]
Abstract
The 2-week, virtual Future of the Search for Life science and engineering workshop brought together more than 100 scientists, engineers, and technologists in March and April 2022 to provide their expert opinion on the interconnections between life-detection science and technology. Participants identified the advances in measurement and sampling technologies they believed to be necessary to perform in situ searches for life elsewhere in our Solar System, 20 years or more in the future. Among suggested measurements for these searches, those pertaining to three potential indicators of life termed "dynamic disequilibrium," "catalysis," and "informational polymers" were identified as particularly promising avenues for further exploration. For these three indicators, small breakout groups of participants identified measurement needs and knowledge gaps, along with corresponding constraints on sample handling (acquisition and processing) approaches for a variety of environments on Enceladus, Europa, Mars, and Titan. Despite the diversity of these environments, sample processing approaches all tend to be more complex than those that have been implemented on missions or envisioned for mission concepts to date. The approaches considered by workshop breakout groups progress from nondestructive to destructive measurement techniques, and most involve the need for fluid (especially liquid) sample processing. Sample processing needs were identified as technology gaps. These gaps include technology and associated sampling strategies that allow the preservation of the thermal, mechanical, and chemical integrity of the samples upon acquisition; and to optimize the sample information obtained by operating suites of instruments on common samples. Crucially, the interplay between science-driven life-detection strategies and their technological implementation highlights the need for an unprecedented level of payload integration and extensive collaboration between scientists and engineers, starting from concept formulation through mission deployment of life-detection instruments and sample processing systems.
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Affiliation(s)
- Marc Neveu
- Department of Astronomy, University of Maryland, College Park, Maryland, USA
- NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
| | - Richard Quinn
- NASA Ames Research Center, Moffett Field, California, USA
| | - Laura M Barge
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - Kathleen L Craft
- Applied Physics Laboratory, Johns Hopkins University, Laurel, Maryland, USA
| | | | | | | | - Macarena Parra
- NASA Ames Research Center, Moffett Field, California, USA
| | | | - Francesca Cary
- Hawai'i Institute of Geophysics and Planetology, University of Hawai'i, Mānoa, Hawaii, USA
| | - Andrea Corpolongo
- Department of Geosciences, University of Cincinnati, Cincinnati, Ohio, USA
| | - Lucas Fifer
- Department of Earth and Space Sciences, University of Washington, Seattle, Washington, USA
| | - Andrew Gangidine
- Office of Development, Yale University, New Haven, Connecticut, USA
| | - Diana Gentry
- NASA Ames Research Center, Moffett Field, California, USA
| | | | - Zaid Haddadin
- Department of Electrical and Computer Engineering, University of California, San Diego, California, USA
| | - Craig Herbold
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Aila Inaba
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, New Jersey, USA
| | - Seán F Jordan
- School of Chemical Sciences, Dublin City University, Dublin, Ireland
| | - Hemani Kalucha
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, USA
| | - Pavel Klier
- NASA Ames Research Center, Moffett Field, California, USA
- NASA Postdoctoral Program, Oak Ridge Associated Universities, Oak Ridge, Tennessee, USA
| | - Kas Knicely
- Geophysical Institute, University of Alaska, Fairbanks, Alaska, USA
| | - An Y Li
- Department of Earth and Space Sciences, University of Washington, Seattle, Washington, USA
| | - Patrick McNally
- Space Physics Research Laboratory, University of Michigan, Ann Arbor, Michigan, USA
| | - Maëva Millan
- Laboratory Atmosphere and Space Observations, Guyancourt, France
| | - Neveda Naz
- Department of Chemistry, Tufts University, Medford, Massachusetts, USA
| | - Chinmayee Govinda Raj
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Peter Schroedl
- Department of Biology, Boston University, Boston, Massachusetts, USA
| | - Jennifer Timm
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, New Jersey, USA
| | - Ziming Yang
- Department of Chemistry, Oakland University, Rochester, Michigan, USA
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Georgiou CD, McKay C, Reymond JL. Organic Catalytic Activity as a Method for Agnostic Life Detection. Astrobiology 2023; 23:1118-1127. [PMID: 37523279 DOI: 10.1089/ast.2023.0022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/02/2023]
Abstract
An ideal life detection instrument would have high sensitivity but be insensitive to abiotic processes and would be capable of detecting life with alternate molecular structures. In this study, we propose that catalytic activity can be the basis of a nearly ideal life detection instrument. There are several advantages to catalysis as an agnostic life detection method. Demonstrating catalysis does not necessarily require culturing/growing the alien life and in fact may persist even in dead biomass for some time, and the amplification by catalysis is large even by minute amounts of catalysts and, hence, can be readily detected against abiotic background rates. In specific, we propose a hydrolytic catalysis detection instrument that could detect activity in samples of extraterrestrial organic material from unknown life. The instrument uses chromogenic assay-based detection of various hydrolytic catalytic activities, which are matched to corresponding artificial substrates having the same, chromogenic (preferably fluorescent) upon release, group; D- and L-enantiomers of these substrates can be used to also answer the question whether unknown life is chiral. Since catalysis is a time-proportional product-concentration amplification process, hydrolytic catalytic activity can be measured on a sample of even a minute size, and with instruments based on, for example, optofluidic chip technology.
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Affiliation(s)
| | | | - Jean-Louis Reymond
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland
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Papadea P, Kalaitzopoulou E, Skipitari M, Varemmenou A, Papasotiriou M, Papachristou E, Goumenos D, Grune T, Georgiou CD. Novel oxidized LDL-based clinical markers in peritoneal dialysis patients for atherosclerosis risk assessment. Redox Biol 2023; 64:102762. [PMID: 37302344 PMCID: PMC10363433 DOI: 10.1016/j.redox.2023.102762] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 05/09/2023] [Accepted: 05/23/2023] [Indexed: 06/13/2023] Open
Abstract
Maintenance peritoneal dialysis (PD) is commonly associated with cardiovascular diseases (CVDs), whose risk is assessed via LDL-C. Nonetheless, oxidized LDL (oxLDL), as being a key component of atherosclerotic lesions, could be also associated with atherosclerosis and related CVDs. However, its predictive value for CVDs risk assessment is subject of research studies due to the lack of specific methods to measure oxLDL status from its individual lipid/protein components. In the present study, six novel oxLDL markers, representative of certain oxidative modifications on the LDL protein and lipid components, are measured in atherosclerosis-prone PD patients (39) versus those in chronic kidney disease patients (61) under hemodialysis (HD) and healthy controls (40). LDL from serum of PD, HD and control subjects were isolated and fractionated into cholesteryl esters, triglycerides, free cholesterol, phospholipids and apolipoprotein B100 (apoB100). Subsequently the oxLDL markers cholesteryl ester hydroperoxides (-OOH), triglyceride-OOH, free cholesterol-OOH, phospholipid-OOH, apoB100 malondialdehyde and apoB100 dityrosines were measured. LDL carotenoid levels and LDL particle serum concentration were also measured. The levels of all oxLDL lipid-OOH markers were significantly elevated in PD patients versus control, while the levels of cholesteryl ester-/triglyceride-/free cholesterol-OOH were significantly elevated in PD versus HD patients, regardless of patients' underlying medical conditions, sex, age, PD type, clinical biochemical markers and medication. It should be noted that all fractionated lipid-OOH levels were inversely correlated with LDL-P concentration, while LDL-P concentration was not correlated with LDL-C in PD patients. Moreover, LDL carotenoids were significantly lower in PD patients versus control. The increased levels of oxLDL status specific markers in both PD and HD patients (compared to control), support a potential prognostic value of oxLDL regarding CVD risk assessment in both patient groups. Lastly, the study introduces the oxLDL peroxidation markers free cholesterol-OOH and cholesteryl ester-OOH as complementary to LDL-P number, and as possible alternatives to LDL-C.
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Affiliation(s)
| | | | | | | | | | | | | | - Tilman Grune
- Department of Molecular Toxicology, German Institute of Human Nutrition, Potsdam-Rehbrücke, Germany; German Center for Cardiovascular Research (DZHK), 10117, Berlin, Germany
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Angelis A, Kostakis ID, Lilimpakis K, Kalaitzopoulou E, Papadea P, Skipitari M, Georgiou CD, Vagianos C. Time-Related Evidence of Intestinal Oxidative Stress in Obstructive Jaundice-Induced Rats. Eur Surg Res 2023; 64:323-333. [PMID: 36921589 DOI: 10.1159/000530087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 02/28/2023] [Indexed: 03/17/2023]
Abstract
INTRODUCTION Obstructive jaundice is known to affect intestinal permeability and facilitate bacterial translocation through related mechanisms. This study was conducted to evaluate the alterations concerning blood biochemistry and levels of several markers of oxidative stress (OS) in blood and intestinal mucosa caused by obstructive jaundice and how these fluctuate over time, in order to further explore the possibility of intervening in the OS path in future experiments. METHODS A total of 54 albino Wistar rats were randomly divided into three groups (control, sham operated, and bile duct ligation) and sacrificed at specific time intervals (12 h and 2, 7, and 14 days). The intestinal barrier function was evaluated by measuring endotoxin levels in portal, aortic, and peripheral blood. Also, basic biochemical parameters were simultaneously measured in peripheral blood. Tissue samples collected from the terminal ileum were homogenized for determining the OS markers, lipid peroxidation, and protein-free radical-induced oxidation. RESULTS We designed this experiment to examine the alterations in enteric mucosa primarily in relation to OS in a period of 14 days. During this time period, we investigated in specific time intervals not only OS fluctuations but also other liver function parameters, as well as CRP and endotoxin levels. The alterations were monitored in relation to time after bile duct ligation. CONCLUSION Bile duct ligation in rats causes OS versus post-ligation time progression of the common bile duct. OS was increased by ∼50% compared to control/sham and peaked at 7 days and at least up to 14 days post-ligation. This phenomenon was accompanied with a deranging of liver function after ligation, as anticipated, but not in all measured parameters; biochemical and endotoxin levels followed the same pattern.
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Affiliation(s)
- Apostolos Angelis
- Second Department of Propaedeutic Surgery, National and Kapodistrian University of Athens, Athens, Greece
| | - Ioannis D Kostakis
- Department of Hepato-Pancreato-Biliary Surgery and Liver Transplantation, Royal Free Hospital, Royal Free London NHS Foundation Trust, London, UK
| | | | | | | | | | | | - Costas Vagianos
- Second Department of Propaedeutic Surgery, National and Kapodistrian University of Athens, Athens, Greece
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Papadea P, Skipitari M, Kalaitzopoulou E, Varemmenou A, Spiliopoulou M, Papasotiriou M, Papachristou E, Goumenos D, Onoufriou A, Rosmaraki E, Margiolaki I, Georgiou CD. Methods on LDL particle isolation, characterization, and component fractionation for the development of novel specific oxidized LDL status markers for atherosclerotic disease risk assessment. Front Med (Lausanne) 2023; 9:1078492. [PMID: 36687450 PMCID: PMC9851470 DOI: 10.3389/fmed.2022.1078492] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 12/05/2022] [Indexed: 01/06/2023] Open
Abstract
The present study uses simple, innovative methods to isolate, characterize and fractionate LDL in its main components for the study of specific oxidations on them that characterize oxidized low-density lipoprotein (oxLDL) status, as it causatively relates to atherosclerosis-associated cardiovascular disease (CVD) risk assessment. These methods are: (a) A simple, relatively time-short, low cost protocol for LDL isolation, to avoid shortcomings of the currently employed ultracentrifugation and affinity chromatography methodologies. (b) LDL purity verification by apoB100 SDS-PAGE analysis and by LDL particle size determination; the latter and its serum concentration are determined in the present study by a simple method more clinically feasible as marker of CVD risk assessment than nuclear magnetic resonance. (c) A protocol for LDL fractionation, for the first time, into its main protein/lipid components (apoB100, phospholipids, triglycerides, free cholesterol, and cholesteryl esters), as well as into LDL carotenoid/tocopherol content. (d) Protocols for the measurement, for the first time, of indicative specific LDL component oxidative modifications (cholesteryl ester-OOH, triglyceride-OOH, free cholesterol-OOH, phospholipid-OOH, apoB100-MDA, and apoB100-DiTyr) out of the many (known/unknown/under development) that collectively define oxLDL status, which contrasts with the current non-specific oxLDL status evaluation methods. The indicative oxLDL status markers, selected in the present study on the basis of expressing early oxidative stress-induced oxidative effects on LDL, are studied for the first time on patients with end stage kidney disease on maintenance hemodialysis, selected as an indicative model for atherosclerosis associated diseases. Isolating LDL and fractionating its protein and main lipid components, as well as its antioxidant arsenal comprised of carotenoids and tocopherols, paves the way for future studies to investigate all possible oxidative modifications responsible for turning LDL to oxLDL in association to their possible escaping from LDL's internal antioxidant defense. This can lead to studies to identify those oxidative modifications of oxLDL (after their artificial generation on LDL), which are recognized by macrophages and convert them to foam cells, known to be responsible for the formation of atherosclerotic plaques that lead to the various CVDs.
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Affiliation(s)
| | | | | | | | | | - Marios Papasotiriou
- Department of Nephrology, General University Hospital of Patras, Patras, Greece,Marios Papasotiriou,
| | | | - Dimitrios Goumenos
- Department of Nephrology, General University Hospital of Patras, Patras, Greece
| | - Anny Onoufriou
- Department of Microbiology, General University Hospital of Patras, University of Patras Medical School, Patras, Greece
| | | | | | - Christos D. Georgiou
- Department of Biology, University of Patras, Patras, Greece,*Correspondence: Christos D. Georgiou,
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Lilimpakis K, Tsepelaki A, Kalaitzopoulou E, Zisimopoulos D, Papadea P, Skipitari M, Varemmenou A, Aggelis A, Vagianos C, Constantoyannis C, Georgiou CD. Time progression and regional expression of brain oxidative stress induced by obstructive jaundice in rats. Lab Anim Res 2022; 38:35. [PMID: 36434681 PMCID: PMC9701014 DOI: 10.1186/s42826-022-00146-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 11/10/2022] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Obstructive jaundice induces oxidative changes in the brain parenchyma and plays significant role in clinical manifestations of hepatic encephalopathy. We aim to study the progression of the brain oxidative status over time and the differences of its pattern over the hemispheres, the brainstem and the cerebellum. We use an experimental model in rats and measuring the oxidative stress (OS) specific biomarkers protein malondialdehyde (PrMDA) and protein carbonyls (PrC = O). RESULTS Hyperbilirubinemia has been confirmed in all study groups as the result of common bile duct obstruction. We confirmed increase in both PrMDA and PrC = O biomarkers levels with different type of changes over time. We also confirmed that the oxidative process develops differently in each of the brain areas in study. CONCLUSIONS The present study confirms the progressive increase in OS in all brain areas studied using markers indicative of cumulative protein modification.
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Affiliation(s)
- Konstantinos Lilimpakis
- grid.11047.330000 0004 0576 5395Department of Medicine, Department of Neurosurgery, University of Patras, University Campus, GR26504 Rion, Achaia Patras, Greece ,grid.416564.40000 0004 0622 585XDepartment of Neurosurgery, St. Savvas Hospital, 171 Alexandras Avenue, 11522 Athens, Greece
| | - Aidona Tsepelaki
- grid.5216.00000 0001 2155 0800Department of Medicine, Second Department of Propaedeutic Surgery, National and Kapodistrian University of Athens, 75 Mikras Asias str, 11527 Athens, Goudi Greece
| | - Electra Kalaitzopoulou
- grid.11047.330000 0004 0576 5395Department of Biology, University of Patras, University Campus, GR26504 Rion, Achaia Patras, Greece
| | - Dimitrios Zisimopoulos
- grid.11047.330000 0004 0576 5395Department of Biology, University of Patras, University Campus, GR26504 Rion, Achaia Patras, Greece
| | - Polyxeni Papadea
- grid.11047.330000 0004 0576 5395Department of Biology, University of Patras, University Campus, GR26504 Rion, Achaia Patras, Greece
| | - Marianna Skipitari
- grid.11047.330000 0004 0576 5395Department of Biology, University of Patras, University Campus, GR26504 Rion, Achaia Patras, Greece
| | - Athina Varemmenou
- grid.11047.330000 0004 0576 5395Department of Medicine, Department of Neurosurgery, University of Patras, University Campus, GR26504 Rion, Achaia Patras, Greece
| | - Apostolos Aggelis
- grid.5216.00000 0001 2155 0800Department of Medicine, Second Department of Propaedeutic Surgery, National and Kapodistrian University of Athens, 75 Mikras Asias str, 11527 Athens, Goudi Greece
| | - Constantine Vagianos
- grid.5216.00000 0001 2155 0800Department of Medicine, Second Department of Propaedeutic Surgery, National and Kapodistrian University of Athens, 75 Mikras Asias str, 11527 Athens, Goudi Greece
| | - Constantine Constantoyannis
- grid.11047.330000 0004 0576 5395Department of Medicine, Department of Neurosurgery, University of Patras, University Campus, GR26504 Rion, Achaia Patras, Greece
| | - Christos D. Georgiou
- grid.11047.330000 0004 0576 5395Department of Biology, University of Patras, University Campus, GR26504 Rion, Achaia Patras, Greece
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Habeos GI, Filippopoulou F, Habeos EE, Kalaitzopoulou E, Skipitari M, Papadea P, Lagoumintzis G, Niarchos A, Georgiou CD, Chartoumpekis DV. Maternal Calorie Restriction Induces a Transcriptional Cytoprotective Response in Embryonic Liver Partially Dependent on Nrf2. Antioxidants (Basel) 2022; 11:2274. [PMID: 36421460 PMCID: PMC9687455 DOI: 10.3390/antiox11112274] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 11/07/2022] [Accepted: 11/15/2022] [Indexed: 08/27/2023] Open
Abstract
BACKGROUND Calorie restriction is known to enhance Nrf2 signaling and longevity in adult mice, partially by reducing reactive oxygen species, but calorie restriction during pregnancy leads to intrauterine growth retardation. The latter is associated with fetal reprogramming leading to increased incidence of obesity, metabolic syndrome and diabetes in adult life. Transcription factor Nrf2 is a central regulator of the antioxidant response and its crosstalk with metabolic pathways is emerging. We hypothesized that the Nrf2 pathway is induced in embryos during calorie restriction in pregnant mothers. METHODS From gestational day 10 up to day 16, 50% of the necessary mouse diet was provided to Nrf2 heterozygous pregnant females with fathers being of the same genotype. Embryos were harvested at the end of gestational day 16 and fetal liver was used for qRT-PCR and assessment of oxidative stress (OS). RESULTS Intrauterine calorie restriction led to upregulation of mRNA expression of antioxidant genes (Nqo1, Gsta1, Gsta4) and of genes related to integrated stress response (Chac1, Ddit3) in WT embryos. The expression of a key gluconeogenic (G6pase) and two lipogenic genes (Acacb, Fasn) was repressed in calorie-restricted embryos. In Nrf2 knockout embryos, the induction of Nqo1 and Gsta1 genes was abrogated while that of Gsta4 was preserved, indicating an at least partially Nrf2-dependent induction of antioxidant genes after in utero calorie restriction. Measures of OS showed no difference (superoxide radical and malondialdehyde) or a small decrease (thiobarbituric reactive substances) in calorie-restricted WT embryos. CONCLUSIONS Calorie restriction during pregnancy elicits the transcriptional induction of cytoprotective/antioxidant genes in the fetal liver, which is at least partially Nrf2-dependent, with a physiological significance that warrants further investigation.
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Affiliation(s)
- George I. Habeos
- Division of Endocrinology, Department of Internal Medicine, School of Medicine, University of Patras, 26504 Patras, Greece
| | - Fotini Filippopoulou
- Division of Endocrinology, Department of Internal Medicine, School of Medicine, University of Patras, 26504 Patras, Greece
| | - Evagelia E. Habeos
- Division of Endocrinology, Department of Internal Medicine, School of Medicine, University of Patras, 26504 Patras, Greece
| | - Electra Kalaitzopoulou
- Section of Genetics, Cell Biology and Development, Department of Biology, University of Patras, 26504 Patras, Greece
| | - Marianna Skipitari
- Section of Genetics, Cell Biology and Development, Department of Biology, University of Patras, 26504 Patras, Greece
| | - Polyxeni Papadea
- Section of Genetics, Cell Biology and Development, Department of Biology, University of Patras, 26504 Patras, Greece
| | - George Lagoumintzis
- Division of Endocrinology, Department of Internal Medicine, School of Medicine, University of Patras, 26504 Patras, Greece
- Department of Pharmacy, University of Patras, 26504 Patras, Greece
| | - Athanasios Niarchos
- Division of Endocrinology, Department of Internal Medicine, School of Medicine, University of Patras, 26504 Patras, Greece
| | - Christos D. Georgiou
- Section of Genetics, Cell Biology and Development, Department of Biology, University of Patras, 26504 Patras, Greece
| | - Dionysios V. Chartoumpekis
- Division of Endocrinology, Department of Internal Medicine, School of Medicine, University of Patras, 26504 Patras, Greece
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Zisimopoulos DN, Kalaitzopoulou E, Skipitari M, Papadea P, Panagopoulos NT, Salahas G, Georgiou CD. Detection of superoxide radical in all biological systems by Thin Layer Chromatography. Arch Biochem Biophys 2021; 716:109110. [PMID: 34958749 DOI: 10.1016/j.abb.2021.109110] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 12/15/2021] [Accepted: 12/16/2021] [Indexed: 12/20/2022]
Abstract
The study presents a new method that detects O2•-, via quantification of 2-hydroxyethidium (2-ΟΗ-Ε+) as low as ∼30 fmoles by High-Performance Thin Layer Chromatography (HPTLC). The method isolates 2-ΟΗ-Ε+ after its extraction by the anionic detergent SDS (at 18-fold higher than its CMC) together with certain organic/inorganic reagents, and its HPTLC-separation from di-ethidium (di-Ε+) and ethidium (Ε+). Quantification of 2-OH-E+ is based on its ex/em maxima at 290/540 nm, and of di-E+ and E+ at 295/545 nm. The major innovations of the present method are the development of protocols for (i) efficient extraction (by SDS) and (ii) sensitive quantification (by HPTLC) for 2-OH-E+ (as well as di-E+ and E+) from most biological systems (animals, plants, cells, subcellular compartments, fluids). The method extracts 2-ΟΗ-Ε+ (by neutralizing the strong binding between its quaternary N+ and negatively charged sites on phospholipids, DNA etc) together with free HE, while protects both from biological oxidases, and also extracts/quantifies total proteins (hydrophilic and hydrophobic) for expressing O2•- levels per protein quantity. The method also uses SDS (at 80-fold lower than its CMC) to extract/remove/wash 2-ΟΗ-Ε+ from cell/organelle exterior membrane sites, for more accurate internal content quantification. The new method is applied on indicative biological systems: (1) artificially stressed (mouse organs and liver mitochondria and nuclei, ±exposed to paraquat, a known O2•- generator), and (2) physiologically stressed (cauliflower plant, exposed to light/dark).
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Affiliation(s)
- Dimitrios N Zisimopoulos
- Section of Genetics, Cell Biology and Development, Department of Biology, University of Patras, Patras, Greece.
| | - Electra Kalaitzopoulou
- Section of Genetics, Cell Biology and Development, Department of Biology, University of Patras, Patras, Greece.
| | - Marianna Skipitari
- Section of Genetics, Cell Biology and Development, Department of Biology, University of Patras, Patras, Greece.
| | - Polyxeni Papadea
- Section of Genetics, Cell Biology and Development, Department of Biology, University of Patras, Patras, Greece.
| | | | | | - Christos D Georgiou
- Section of Genetics, Cell Biology and Development, Department of Biology, University of Patras, Patras, Greece.
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Kostopoulou E, Kalaitzopoulou E, Papadea P, Skipitari M, Rojas Gil AP, Spiliotis BE, Georgiou CD. Oxidized lipid-associated protein damage in children and adolescents with type 1 diabetes mellitus: New diagnostic/prognostic clinical markers. Pediatr Diabetes 2021; 22:1135-1142. [PMID: 34633133 DOI: 10.1111/pedi.13271] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 09/21/2021] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Type 1 diabetes mellitus (DM1), a chronic metabolic disorder of autoimmune origin, has been associated with oxidative stress (OS), which plays a central role in the onset, progression, and long-term complications of DM1. The markers of OS lipid peroxidation products, lipid hydroperoxides (LOOH), and also malondialdehyde (MDA) and thiobarbituric reactive substances (TBARS) that oxidatively modify proteins (Pr) (i.e., PrMDA and PrTBARS, respectively), have been associated with DM2, DM1, diabetic neuropathy, and microalbuminuria. OBJECTIVE/SUBJECTS Here, we investigated LOOH, PrMDA and PrTBARS in 50 children and adolescents with DM1 and 21 controls. RESULTS The novel OS marker PrTBARS was assessed for the first time in children and adolescents with DM1. LOOH and the pair PrMDA/PrTBARS, representing early and late peroxidation stages, respectively, are found to be significantly higher (130%, 50/90%, respectively, at p < 0.001) in patients with DM1 compared to controls. The studied OS parameters did not differ with age, age at diagnosis, sex, duration of DM1, presence of recent ketosis/ketoacidosis, or mode of treatment. CONCLUSIONS We propose that LOOH, PrMDA and the new marker PrTBARS could serve as potential diagnostic clinical markers for identifying OS in children and adolescents with DM1, and may, perhaps, hold promise as a prognostic tool for future complications associated with the disease.
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Affiliation(s)
- Eirini Kostopoulou
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics, University of Patras School of Medicine, Patras, Greece
| | | | | | | | - Andrea Paola Rojas Gil
- Faculty of Health Sciences, Department of Nursing, University of Peloponnese, Tripoli, Greece
| | - Bessie E Spiliotis
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics, University of Patras School of Medicine, Patras, Greece
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Georgiou CD, Margaritis LH. Oxidative Stress and NADPH Oxidase: Connecting Electromagnetic Fields, Cation Channels and Biological Effects. Int J Mol Sci 2021; 22:10041. [PMID: 34576203 PMCID: PMC8470280 DOI: 10.3390/ijms221810041] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 09/01/2021] [Accepted: 09/15/2021] [Indexed: 12/12/2022] Open
Abstract
Electromagnetic fields (EMFs) disrupt the electrochemical balance of biological membranes, thereby causing abnormal cation movement and deterioration of the function of membrane voltage-gated ion channels. These can trigger an increase of oxidative stress (OS) and the impairment of all cellular functions, including DNA damage and subsequent carcinogenesis. In this review we focus on the main mechanisms of OS generation by EMF-sensitized NADPH oxidase (NOX), the involved OS biochemistry, and the associated key biological effects.
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Affiliation(s)
- Christos D. Georgiou
- Department of Biology, Section of Genetics, Cell & Developmental Biology, University of Patras, 10679 Patras, Greece;
| | - Lukas H. Margaritis
- Section of Cell Biology and Biophysics, Department of Biology, National and Kapodistrian University of Athens, 26504 Athens, Greece
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11
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Georgiou CD, McKay CP, Quinn RC, Kalaitzopoulou E, Papadea P, Skipitari M. The Oxygen Release Instrument: Space Mission Reactive Oxygen Species Measurements for Habitability Characterization, Biosignature Preservation Potential Assessment, and Evaluation of Human Health Hazards. Life (Basel) 2019; 9:E70. [PMID: 31461989 PMCID: PMC6789740 DOI: 10.3390/life9030070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 08/21/2019] [Accepted: 08/25/2019] [Indexed: 11/17/2022] Open
Abstract
We describe the design of an instrument, the OxR (for Oxygen Release), for the enzymatically specific and non-enzymatic detection and quantification of the reactive oxidant species (ROS), superoxide radicals (O2•-), and peroxides (O22-, e.g., H2O2) on the surface of Mars and Moon. The OxR instrument is designed to characterize planetary habitability, evaluate human health hazards, and identify sites with high biosignature preservation potential. The instrument can also be used for missions to the icy satellites of Saturn's Titan and Enceladus, and Jupiter's Europa. The principle of the OxR instrument is based on the conversion of (i) O2•- to O2 via its enzymatic dismutation (which also releases H2O2), and of (ii) H2O2 (free or released by the hydrolysis of peroxides and by the dismutation of O2•-) to O2 via enzymatic decomposition. At stages i and ii, released O2 is quantitatively detected by an O2 sensor and stoichiometrically converted to moles of O2•- and H2O2. A non-enzymatic alternative approach is also designed. These methods serve as the design basis for the construction of a new small-footprint instrument for specific oxidant detection. The minimum detection limit of the OxR instrument for O2•- and O22- in Mars, Lunar, and Titan regolith, and in Europa and Enceladus ice is projected to be 10 ppb. The methodology of the OxR instrument can be rapidly advanced to flight readiness by leveraging the Phoenix Wet Chemical Laboratory, or microfluidic sample processing technologies.
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Affiliation(s)
| | | | - Richard C Quinn
- SETI Institute, Carl Sagan Center, Mountain View, CA 94043, USA
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Georgiou CD, Tairis N, Sotiropoulou A. Hydroxyl radical scavengers inhibit lateral-type sclerotial differentiation and growth in phytopathogenic fungi. Mycologia 2019. [DOI: 10.1080/00275514.2000.12061226] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Christos D. Georgiou
- Section of Genetics, Cell Biology and Development, Department of Biology, University of Patra, 26100 Patra, Greece
| | - Nikos Tairis
- Section of Genetics, Cell Biology and Development, Department of Biology, University of Patra, 26100 Patra, Greece
| | - Anna Sotiropoulou
- Section of Genetics, Cell Biology and Development, Department of Biology, University of Patra, 26100 Patra, Greece
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Sideri M, Georgiou CD. Differentiation and hydrogen peroxide production in Sclerotium rolfsii are induced by the oxidizing growth factors, light and iron. Mycologia 2019. [DOI: 10.1080/00275514.2000.12061248] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Marina Sideri
- Section of Genetics, Cell Biology and Development, Department of Biology, University of Patra, 26100 Patra, Greece
| | - Christos D. Georgiou
- Section of Genetics, Cell Biology and Development, Department of Biology, University of Patra, 26100 Patra, Greece
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14
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Affiliation(s)
- Christos D. Georgiou
- University of Patra, Department of Biology, Section of Genetics, Cell & Developmental Biology, Patra-26100, Greece
| | - Marina Sideri
- University of Patra, Department of Biology, Section of Genetics, Cell & Developmental Biology, Patra-26100, Greece
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15
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Papadopoulou G, Zisimopoulos D, Kalaitzopoulou E, Makri OE, Tsapardoni FN, Georgakopoulos CD, Georgiou CD. Age-related aqueous humor (AH) and lens epithelial cell/capsule protein carbonylation and AH protein concentration in cataract patients who have pseudoexfoliative diseases. Mol Vis 2018; 24:890-901. [PMID: 30713426 PMCID: PMC6334981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2018] [Accepted: 12/31/2018] [Indexed: 10/29/2022] Open
Abstract
Purpose The aim of this study is to investigate the age-correlation of oxidative stress (OS, assessed by the accumulative OS damage marker protein carbonyls) in aqueous humour (AH; together with protein concentration) and lens epithelial cells plus capsule (LECs/capsule) in patients with cataract (CAT), and also suffering from pseudoexfoliation syndrome (PEX), primary open-angle glaucoma (POAG) and pseudoexfoliation glaucoma (PXG). Methods AH samples from 78 male/female patients (21, 20, 19 and 18 with CAT, PEX, PXG, and POAG, respectively), and LECs/capsule samples from 104 male/female patients (34, 32, 18, and 20 with CAT, PEX, PXG and POAG, respectively) were collected during phacoemulsification CAT surgery. Average protein carbonyl concentrations were measured in patients grouped in 5-year age intervals (ranging from 56-60 to 86-90). The non-overlapping age ranges and numbers of the tested subjects did not allow comparative follow up studies for the tested diseases. Results There is an age-dependent increase of protein carbonyls in AH (nmol mg-1 protein and ml-1), and in the order CAT<PXG=~POAG<PEX and CAT<PEX=~POAG<PXG respectively. Moreover, protein concentration in AH accumulates in the order CAT<PEX<POAG<PXG but is not age-related. An age-dependent increase of protein carbonyls (nmol mg-1 protein) is also observed in LECs/capsule, and in the order CAT<PEX=~POAG<PXG. Conclusions The present study shows for the first time an age-increased OS-induced protein damage (protein carbonyl formation) in the AH and LECs/capsule of CAT patients with PEX, POAG or PXG. The slow rate of change of protein carbonyls strongly suggests a long-term implication of OS in ocular disease pathogenesis. Additionally, protein concentration levels in the AH of CAT patients increase independently of age, and in same as with protein carbonyls increasing order levels for CAT<POAG<PXG in AH and LECs/capsule. This may suggest a protein cross-diffusion taking place between AH and LECs/capsule, most likely originating from PEX deposition and/or necrotic/apoptotic LECs/capsule. Moreover, the findings of the present study establish the use of protein carbonyls (together with a methodology for their more accurate quantification, which overcomes serious unreliability problems of past methods) as an age accumulative marker of OS damage, for future studies that investigate long-term OS involvement in pseudoexfoliative ocular disorders.
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Affiliation(s)
| | | | | | - Olga E. Makri
- Department of Ophthalmology, University of Patras, Patras, Greece
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Georgiou CD. Functional Properties of Amino Acid Side Chains as Biomarkers of Extraterrestrial Life. Astrobiology 2018; 18:1479-1496. [PMID: 30129781 PMCID: PMC6211371 DOI: 10.1089/ast.2018.1868] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 07/10/2018] [Indexed: 05/22/2023]
Abstract
The present study proposes to search our solar system (Mars, Enceladus, Europa) for patterns of organic molecules that are universally associated with biological functions and structures. The functions are primarily catalytic because life could only have originated within volume/space-constrained compartments containing chemical reactions catalyzed by certain polymers. The proposed molecular structures are specific groups in the side chains of amino acids with the highest catalytic propensities related to life on Earth, that is, those that most frequently participate as key catalytic groups in the active sites of enzymes such as imidazole, thiol, guanidinium, amide, and carboxyl. Alternatively, these or other catalytic groups can be searched for on non-amino-acid organic molecules, which can be tested for certain hydrolytic catalytic activities. The first scenario assumes that life may have originated in a similar manner as the terrestrial set of α-amino acids, while the second scenario does not set such a requirement. From the catalytic propensity perspective proposed in the first scenario, life must have invented amino acids with high catalytic propensity (His, Cys, Arg) in order to overcome, and be complemented by, the low catalytic propensity of the initially available abiogenic amino acids. The abiogenic and the metabolically invented amino acids with the lowest catalytic propensity can also serve as markers of extraterrestrial life when searching for patterns on the basis of the following functional propensities related to protein secondary/quaternary structure: (1) amino acids that are able to form α-helical intramembrane peptide domains, which can serve as primitive transporters in protocell membrane bilayers and catalysts of simple biochemical reactions; (2) amino acids that tend to accumulate in extremophile proteins of Earth and possibly extraterrestrial life. The catalytic/structural functional propensity approach offers a new perspective in the search for extraterrestrial life and could help unify previous amino acid-based approaches.
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Georgiou CD, Zisimopoulos D, Argyropoulou V, Kalaitzopoulou E, Salachas G, Grune T. Protein and cell wall polysaccharide carbonyl determination by a neutral pH 2,4-dinitrophenylhydrazine-based photometric assay. Redox Biol 2018; 17:128-142. [PMID: 29684819 PMCID: PMC6006683 DOI: 10.1016/j.redox.2018.04.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 04/05/2018] [Accepted: 04/06/2018] [Indexed: 01/05/2023] Open
Abstract
A new 2,4-dinitrophenylhydrazine (DNPH)-based photometric assay is developed for the quantification of carbonyls in protein samples from any biological source by protein carbonyl-DNPH hydrazone formation at acidic pH in the presence of denaturing urea, and subsequent hydrazone solubilization in the presence of SDS and stabilization from acid hydrolysis at pH 7.0. At this neutral (ntr) pH, interfering unreacted DNPH is uncharged and its thus increased hydrophobicity permits its 100% effective removal from the solubilizate with ethyl acetate/hexane wash. The ntrDNPH assay is more reliable and sensitive than the standard (std) DNPH photometric assay because it eliminates its main limitations: (i) interfering unreacted DNPH (pKa 1.55) that is nonspecifically bound to the TCA (pKa 0.7)-protein pellet is not effectively removed after wash with EtOH: ethyl acetate because it is positively charged, (ii) acid (TCA-induced) hydrolysis of the protein carbonyl-DNPH hydrazone, (iii) sample protein concentration re-determination, (iv) loss of sample acid (TCA)-soluble proteins, (v) DNA interference, and (vi) requires high protein quantity samples (≥ 1 mg). Considering ntrDNPH assay's very low protein limit (1 µg), its cumulative and functional sensitivities are 2600- and 2000-fold higher than those of the stdDNPH assay, respectively. The present study elucidates the DNA interference mechanism on the stdDNPH assay, and also develops a standardized protocol for sample protein treatment and fractionation (into cytoplasmic/aqueous, membrane/lipid-bound, and histone/DNA-bound proteins; see Supplement section V) in order to ensure reproducible carbonyl determination on defined cell protein fractions, and to eliminate assay interference from protein samples containing (i) Cys sulfenic acid groups (via their neutralization with dithiothreitol), and (ii) DNA (via its removal by streptomycin sulfate precipitation). Lastly, the ntrDNPH assay determines carbonyl groups on cell wall polysaccharides, thus paving the way on studies to investigate cell walls acting as antioxidant defense in plants, fungi, bacteria and lichens.
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Affiliation(s)
| | | | | | | | - George Salachas
- Department of Agricultural Technology, TEI of Western Greece, Patras, Greece
| | - Tilman Grune
- Department of Molecular Toxicology, German Institute of Human Nutrition, Nuthetal, Germany
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Taprantzi D, Zisimopoulos D, Thomopoulos KC, Spiliopoulou I, Georgiou CD, Tsiaoussis G, Triantos C, Gogos CA, Labropoulou-Karatza C, Assimakopoulos SF. Propranolol reduces systemic oxidative stress and endotoxemia in cirrhotic patients with esophageal varices. Ann Gastroenterol 2018; 31:224-230. [PMID: 29507470 PMCID: PMC5825953 DOI: 10.20524/aog.2017.0222] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 11/03/2017] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND The aim of the study was to investigate the effect of propranolol on systemic oxidative stress and endotoxemia in patients with liver cirrhosis and clinically significant portal hypertension evidenced by the presence of esophageal varices. METHODS Fourteen patients with liver cirrhosis and esophageal varices, not previously been treated with non-selective beta-blockers (NSBB), were prospectively started on propranolol and followed up for three months. Serum early and late lipid peroxidation products (lipid hydroperoxides [LOOH] and malondialdehyde [MDA], respectively), and endotoxin concentrations in peripheral blood were measured. Fourteen age- and sex-matched healthy individuals were used as controls. RESULTS Patients with liver cirrhosis presented significantly higher systemic oxidative stress and endotoxin concentrations compared to healthy controls (P<0.001). Propranolol treatment for one month significantly reduced serum MDA (P<0.05), LOOH (P<0.01), and endotoxin levels (P<0.01) compared to pre-treatment values, whilst LOOH reached control levels. At three months of propranolol treatment, serum LOOH did not differ significantly from the one-month values, whilst serum endotoxin and MDA levels were further reduced between 3- and 1-month period (P<0.05 and P<0.01, respectively), with the latter reaching control levels. Amelioration of systemic endotoxemia at the one- and three-month follow-up intervals (compared to pre-treatment values) was not correlated with the respective reductions in serum MDA and LOOH. CONCLUSIONS This is the first study to show that NSBB treatment in liver cirrhosis exerts a significant systemic antioxidant action. This effect seems to be, at least partly, independent of their beneficial effects on intestinal barrier function and endotoxemia.
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Affiliation(s)
- Dimitra Taprantzi
- Department of Internal Medicine, University Hospital of Patras (Dimitra Taprantzi, Charalambos A. Gogos, Chrisoula Labropoulou-Karatza, Stelios F. Assimakopoulos), Greece
| | - Dimitrios Zisimopoulos
- Department of Biology, University of Patras (Dimitrios Zisimopoulos, Christos D. Georgiou), Greece
| | - Konstantinos C. Thomopoulos
- Division of Gastroenterology, Department of Internal Medicine, University Hospital of Patras (Konstantinos C. Thomopoulos, Georgios Tsiaoussis, Christos Triantos), Greece
| | - Iris Spiliopoulou
- Department of Microbiology, University Hospital of Patras (Iris Spiliopoulou), Greece
| | - Christos D. Georgiou
- Department of Biology, University of Patras (Dimitrios Zisimopoulos, Christos D. Georgiou), Greece
| | - Georgios Tsiaoussis
- Division of Gastroenterology, Department of Internal Medicine, University Hospital of Patras (Konstantinos C. Thomopoulos, Georgios Tsiaoussis, Christos Triantos), Greece
| | - Christos Triantos
- Division of Gastroenterology, Department of Internal Medicine, University Hospital of Patras (Konstantinos C. Thomopoulos, Georgios Tsiaoussis, Christos Triantos), Greece
| | - Charalambos A. Gogos
- Department of Internal Medicine, University Hospital of Patras (Dimitra Taprantzi, Charalambos A. Gogos, Chrisoula Labropoulou-Karatza, Stelios F. Assimakopoulos), Greece
| | - Chrisoula Labropoulou-Karatza
- Department of Internal Medicine, University Hospital of Patras (Dimitra Taprantzi, Charalambos A. Gogos, Chrisoula Labropoulou-Karatza, Stelios F. Assimakopoulos), Greece
| | - Stelios F. Assimakopoulos
- Department of Internal Medicine, University Hospital of Patras (Dimitra Taprantzi, Charalambos A. Gogos, Chrisoula Labropoulou-Karatza, Stelios F. Assimakopoulos), Greece
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Karavassili F, Valmas A, Fili S, Georgiou CD, Margiolaki I. In Quest for Improved Drugs against Diabetes: The Added Value of X-ray Powder Diffraction Methods. Biomolecules 2017; 7:E63. [PMID: 28829407 PMCID: PMC5618244 DOI: 10.3390/biom7030063] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 08/14/2017] [Accepted: 08/16/2017] [Indexed: 01/04/2023] Open
Abstract
Human insulin (HI) is a well-characterized natural hormone which regulates glycose levels into the blood-stream and is widely used for diabetes treatment. Numerous studies have manifested that despite significant efforts devoted to structural characterization of this molecule and its complexes with organic compounds (ligands), there is still a rich diagram of phase transitions and novel crystalline forms to be discovered. Towards the improvement of drug delivery, identification of new insulin polymorphs from polycrystalline samples, simulating the commercially available drugs, is feasible today via macromolecular X-ray powder diffraction (XRPD). This approach has been developed, and is considered as a respectable method, which can be employed in biosciences for various purposes, such as observing phase transitions and characterizing bulk pharmaceuticals. An overview of the structural studies on human insulin complexes performed over the past decade employing both synchrotron and laboratory sources for XRPD measurements, is reported herein. This review aims to assemble all of the recent advances in the diabetes treatment field in terms of drug formulation, verifying in parallel the efficiency and applicability of protein XRPD for quick and accurate preliminary structural characterization in the large scale.
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Affiliation(s)
- Fotini Karavassili
- Section of Genetics, Cell Biology and Development, Department of Biology, University of Patras, GR-26500 Patras, Greece.
| | - Alexandros Valmas
- Section of Genetics, Cell Biology and Development, Department of Biology, University of Patras, GR-26500 Patras, Greece.
| | - Stavroula Fili
- Section of Genetics, Cell Biology and Development, Department of Biology, University of Patras, GR-26500 Patras, Greece.
| | - Christos D Georgiou
- Section of Genetics, Cell Biology and Development, Department of Biology, University of Patras, GR-26500 Patras, Greece.
| | - Irene Margiolaki
- Section of Genetics, Cell Biology and Development, Department of Biology, University of Patras, GR-26500 Patras, Greece.
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Botsakis K, Mourtzi T, Panagiotakopoulou V, Vreka M, Stathopoulos GT, Pediaditakis I, Charalampopoulos I, Gravanis A, Delis F, Antoniou K, Zisimopoulos D, Georgiou CD, Panagopoulos NT, Matsokis N, Angelatou F. BNN-20, a synthetic microneurotrophin, strongly protects dopaminergic neurons in the "weaver" mouse, a genetic model of dopamine-denervation, acting through the TrkB neurotrophin receptor. Neuropharmacology 2017; 121:140-157. [PMID: 28461162 DOI: 10.1016/j.neuropharm.2017.04.043] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 04/26/2017] [Accepted: 04/27/2017] [Indexed: 12/23/2022]
Abstract
Neurotrophic factors are among the most promising treatments aiming at slowing or stopping and even reversing Parkinson's disease (PD). However, in most cases, they cannot readily cross the human blood-brain-barrier (BBB). Herein, we propose as a therapeutic for PD the small molecule 17-beta-spiro-[5-androsten-17,2'-oxiran]-3beta-ol (BNN-20), a synthetic analogue of DHEA, which crosses the BBB and is deprived of endocrine side-effects. Using the "weaver" mouse, a genetic model of PD, which exhibits progressive dopaminergic neurodegeneration in the Substantia Nigra (SN), we have shown that long-term administration (P1-P21) of BNN-20 almost fully protected the dopaminergic neurons and their terminals, via i) a strong anti-apoptotic effect, probably mediated through the Tropomyosin receptor kinase B (TrkB) neurotrophin receptor's PI3K-Akt-NF-κB signaling pathway, ii) by exerting an efficient antioxidant effect, iii) by inducing significant anti-inflammatory activity and iv) by restoring Brain-Derived Neurotrophic Factor (BDNF) levels. By intercrossing "weaver" with NGL mice (dual GFP/luciferase-NF-κΒ reporter mice, NF-κΒ.GFP.Luc), we obtained Weaver/NGL mice that express the NF-κB reporter in all somatic cells. Acute BNN-20 administration to Weaver/NGL mice induced a strong NF-κB-dependent transcriptional response in the brain as detected by bioluminescence imaging, which was abolished by co-administration of the TrkB inhibitor ANA-12. This indicates that BNN-20 exerts its beneficial action (at least in part) through the TrkB-PI3K-Akt-NF-κB signaling pathway. These results could be of clinical relevance, as they suggest BNN-20 as an important neuroprotective agent acting through the TrkB neurotrophin receptor pathway, mimicking the action of the endogenous neurotrophin BDNF. Thus BNN-20 could be proposed for treatment of PD.
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Affiliation(s)
- Konstantinos Botsakis
- Department of Physiology, School of Medicine, University of Patras, Patras, 26 500, Greece
| | - Theodora Mourtzi
- Laboratory of Human and Animal Physiology, Department of Biology, University of Patras, Patras, 26 500, Greece
| | - Vasiliki Panagiotakopoulou
- Laboratory of Human and Animal Physiology, Department of Biology, University of Patras, Patras, 26 500, Greece
| | - Malamati Vreka
- Department of Physiology, School of Medicine, University of Patras, Patras, 26 500, Greece
| | | | - Iosif Pediaditakis
- Department of Pharmacology, School of Medicine, University of Crete, Heraklion 71110, Greece
| | | | - Achilleas Gravanis
- Department of Pharmacology, School of Medicine, University of Crete, Heraklion 71110, Greece; Institute of Molecular Biology & Biotechnology Foundation for Research & Technology - Hellas, GR, 70013, Heraklion, Crete, Greece
| | - Foteini Delis
- Department of Pharmacology, School of Medicine, University of Ioannina, Ioannina 45110, Greece
| | - Katerina Antoniou
- Department of Pharmacology, School of Medicine, University of Ioannina, Ioannina 45110, Greece
| | | | | | - Nikolaos T Panagopoulos
- Laboratory of Human and Animal Physiology, Department of Biology, University of Patras, Patras, 26 500, Greece
| | - Nikolaos Matsokis
- Laboratory of Human and Animal Physiology, Department of Biology, University of Patras, Patras, 26 500, Greece
| | - Fevronia Angelatou
- Department of Physiology, School of Medicine, University of Patras, Patras, 26 500, Greece.
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Georgiou CD, Zisimopoulos D, Kalaitzopoulou E, Quinn RC. Radiation-Driven Formation of Reactive Oxygen Species in Oxychlorine-Containing Mars Surface Analogues. Astrobiology 2017; 17:319-336. [PMID: 28418706 DOI: 10.1089/ast.2016.1539] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The present study demonstrates that γ-radiolyzed perchlorate-containing Mars soil salt analogues (in a CO2 atmosphere) generate upon H2O wetting the reactive oxygen species (ROS) superoxide radical (O2•-), hydrogen peroxide (H2O2), and hydroxyl radicals (•OH). This study also validates that analogue radiolysis forms oxychlorine species that, in turn, can UV-photolyze to •OH upon UV photolysis. This investigation was made possible by the development of a new assay for inorganic-origin O2•- and H2O2 determination and by the modification of a previous assay for soil •OH. Results show that radiolyzed Mg(ClO4)2 generates H2O2 and •OH; and when included as part of a mixture analogous to the salt composition of samples analyzed at the Mars Phoenix site, the analogue generated O2•-, H2O2, and •OH, with •OH levels 150-fold higher than in the radiolyzed Mg(ClO4)2 samples. Radiolyzed Mars Phoenix site salt analogue that did not contain Mg(ClO4)2 generated only •OH also at 150-fold higher concentration than Mg(ClO4)2 alone. Additionally, UV photolysis of the perchlorate γ radiolysis product chlorite (ClO2-) generated the oxychlorine products trihalide (Cl3-), chlorine dioxide (ClO2•), and hypochlorite (ClO-), with the formation of •OH by UV photolysis of ClO-. While the generation of ROS may have contributed in part to 14CO2 production in the Viking Labeled Release (LR) experiment and O2 (g) release in the Viking Gas Exchange (GEx) experiment, our results indicate that they are not likely to be the major contributor to the LR and GEx results. However, due to their highly reactive nature, they are expected to play a significant role in the alteration of organics on Mars. Additionally, experiments with hypochlorite show that the thermal stability of NaClO is in the range of the thermal stability observed for thermally liable oxidant responsible for the Viking LR results. Key Words: Mars-Oxygen-Salts-Radiation-Habitability. Astrobiology 17, 319-336.
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Affiliation(s)
| | | | | | - Richard C Quinn
- 2 Exobiology Branch, NASA Ames Research Center , Moffett Field, California, USA
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Affiliation(s)
| | | | - Katerine P. Petropoulou
- Section of Genetics, Cell Biology and Development, Department of Biology, University of Patras, 26100—Patra, Greece
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Georgiou CD, Zisimopoulos D, Panagiotidis K, Grintzalis K, Papapostolou I, Quinn RC, McKay CP, Sun HJ. Martian Superoxide and Peroxide O2 Release (OR) Assay: A New Technology for Terrestrial and Planetary Applications. Astrobiology 2016; 16:126-142. [PMID: 26881470 DOI: 10.1089/ast.2015.1345] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
This study presents an assay for the detection and quantification of soil metal superoxides and peroxides in regolith and soil. The O2 release (OR) assay is based on the enzymatic conversion of the hydrolysis products of metal oxides to O2 and their quantification by an O2 electrode based on the stoichiometry of the involved reactions. The intermediate product O₂˙⁻ from the hydrolysis of metal superoxides is converted by cytochrome c to O2 and by superoxide dismutase (SOD) to ½ mol O2 and ½ mol H2O2, which is then converted by catalase (CAT) to ½ mol O2. The product H2O2 from the hydrolysis of metal peroxides and hydroperoxides is converted to ½ mol O2 by CAT. The assay method was validated in a sealed sample chamber by using a liquid-phase Clark-type O2 electrode with known concentrations of O₂˙⁻ and H2O2, and commercial metal superoxide and peroxide mixed with Mars analog Mojave and Atacama Desert soils. Carbonates and perchlorates, both present on Mars, do not interfere with the assay. The assay lower limit of detection, when using luminescence quenching/optical sensing O2-electrodes, is 1 nmol O2 cm(-3) or better. The activity of the assay enzymes SOD and cytochrome c was unaffected up to 6 Gy exposure by γ radiation, while CAT retained 100% and 40% of its activity at 3 and 6 Gy, respectively, which demonstrates the suitability of these enzymes for planetary missions, for example, on Mars or Europa.
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Affiliation(s)
| | | | | | | | | | - Richard C Quinn
- 2 SETI Institute, Carl Sagan Center , Mountain View, California, USA
| | | | - Henry J Sun
- 4 Desert Research Institute , Las Vegas, Nevada, USA
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Abstract
The conditions and properties of hydrothermal vents and hydrothermal fields are compared in terms of their ability to support processes related to the origin of life. The two sites can be considered as alternative hypotheses, and from this comparison we propose a series of experimental tests to distinguish between them, focusing on those that involve concentration of solutes, self-assembly of membranous compartments, and synthesis of polymers. Key Word: Hydrothermal systems.
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Affiliation(s)
- David W Deamer
- 1 Department of Biomolecular Engineering, Baskin School of Engineering, University of California , Santa Cruz, California, USA
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Grintzalis K, Georgiou CD, Schneider YJ. An accurate and sensitive Coomassie Brilliant Blue G-250-based assay for protein determination. Anal Biochem 2015; 480:28-30. [DOI: 10.1016/j.ab.2015.03.024] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 03/05/2015] [Accepted: 03/23/2015] [Indexed: 11/28/2022]
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Georgiou CD, Sun HJ, McKay CP, Grintzalis K, Papapostolou I, Zisimopoulos D, Panagiotidis K, Zhang G, Koutsopoulou E, Christidis GE, Margiolaki I. Evidence for photochemical production of reactive oxygen species in desert soils. Nat Commun 2015; 6:7100. [PMID: 25960012 DOI: 10.1038/ncomms8100] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Accepted: 04/01/2015] [Indexed: 11/09/2022] Open
Abstract
The combination of intense solar radiation and soil desiccation creates a short circuit in the biogeochemical carbon cycle, where soils release significant amounts of CO2 and reactive nitrogen oxides by abiotic oxidation. Here we show that desert soils accumulate metal superoxides and peroxides at higher levels than non-desert soils. We also show the photogeneration of equimolar superoxide and hydroxyl radical in desiccated and aqueous soils, respectively, by a photo-induced electron transfer mechanism supported by their mineralogical composition. Reactivity of desert soils is further supported by the generation of hydroxyl radical via aqueous extracts in the dark. Our findings extend to desert soils the photogeneration of reactive oxygen species by certain mineral oxides and also explain previous studies on desert soil organic oxidant chemistry and microbiology. Similar processes driven by ultraviolet radiation may be operating in the surface soils on Mars.
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Affiliation(s)
| | - Henry J Sun
- Desert Research Institute, Las Vegas, Nevada 89119, USA
| | | | | | | | | | | | - Gaosen Zhang
- Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 73000, China
| | - Eleni Koutsopoulou
- Laboratory of Electron Microscopy and Microanalysis, University of Patras, Patras 26500, Greece
| | - George E Christidis
- Department of Mineral Resources Engineering, Technical University of Crete, Chania 73100, Greece
| | - Irene Margiolaki
- Department of Biology, University of Patras, Patras 26504, Greece
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Grintzalis K, Papapostolou I, Zisimopoulos D, Stamatiou I, Georgiou CD. Multiparametric protocol for the determination of thiol redox state in living matter. Free Radic Biol Med 2014; 74:85-98. [PMID: 24996203 DOI: 10.1016/j.freeradbiomed.2014.06.024] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 06/13/2014] [Accepted: 06/20/2014] [Indexed: 12/22/2022]
Abstract
Thiol redox state (TRS) evaluation is mostly restricted to the estimation of GSH and GSSG. However, these TRS parameters can estimate the GSSG/GSH potential, which might be useful for indicating abnormalities in redox metabolism. Nonetheless, evaluation of the multiparameric nature of TRS is required for a more accurate assessment of its physiological role. The present protocol extends the partial assessment of TRS by current methodologies. It measures 15 key parameters of TRS by two modular subprotocols: one for the glutathione (GSH)- and cysteine (CSH)-based nonprotein (NP) thiols/mixed disulfides (i.e., GSH, GSSG, GSSNP, CSH, CSSNP, NPSH, NPSSNP, NP(x)SH(NPSSNP), NP(x)SH(NPSH)), and the other for their protein (P) thiols/mixed disulfides (i.e., PSH, PSSG, PSSC, PSSNP, PSSP, NP(x)SH(PSSNP)). The protocol eliminates autoxidation of GSH and CSH (and thus overestimation of GSSG and CSSNP). Its modularity allows the determination GSH and GSSG also by other published specific assays. The protocol uses three assays; two are based on the photometric reagents 4,4'-dithiopyridine (DTP) and ninhydrin (NHD), and the third on the fluorometric reagent o-phthaldialdehyde (OPT). The initial assays employing these reagents have been extensively modified and redesigned for increased specificity, sensitivity, and simplicity. TRS parameter values and their standard errors are estimated automatically by sets of Excel-adapted algebraic equations. Protocol sensitivity for NPSH, PSH, NPSSNP, PSSP, PSSNP, CSH, CSSNP, PSSC, NP(x)SH(NPSSNP), and NP(x)SH(NPSH) is 1 nmol -SH/CSH, for GSSNP 0.2 nmol, for GSH and GSSG 0.4 nmol, and for PSSG 0.6 nmol. The protocol was applied on human plasma, a sample of high clinical value, and can be also applied in any organism.
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Affiliation(s)
- Konstantinos Grintzalis
- Genetics, Cell and Developmental Biology Section, Department of Biology, University of Patras, Patras, Greece.
| | - Ioannis Papapostolou
- Genetics, Cell and Developmental Biology Section, Department of Biology, University of Patras, Patras, Greece.
| | - Dimitris Zisimopoulos
- Genetics, Cell and Developmental Biology Section, Department of Biology, University of Patras, Patras, Greece.
| | - Irene Stamatiou
- Genetics, Cell and Developmental Biology Section, Department of Biology, University of Patras, Patras, Greece.
| | - Christos D Georgiou
- Genetics, Cell and Developmental Biology Section, Department of Biology, University of Patras, Patras, Greece.
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Papapostolou I, Sideri M, Georgiou CD. Cell proliferating and differentiating role of H2O2 in Sclerotium rolfsii and Sclerotinia sclerotiorum. Microbiol Res 2014; 169:527-32. [DOI: 10.1016/j.micres.2013.12.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Revised: 12/06/2013] [Accepted: 12/07/2013] [Indexed: 11/30/2022]
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Abstract
In 1965, James Lovelock published a general statement, based on thermodynamic chemical equilibrium principles, about how to detect extant or extinct life on a planet other than Earth. Nearly 50 years later, it is possible to make such measurements with robotic missions such as current and future Mars rovers, and probes to sample icy plumes of Enceladus or Europa. We make a specific recommendation that certain characteristic patterns in the composition of lipid hydrocarbons can only result from a biological process, because the signal arises from a universal requirement related to lipid bilayer fluidity and membrane stability. Furthermore, the pattern can be preserved over millions of years, and instrumentation is already available to be incorporated into flight missions.
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Assimakopoulos SF, Tsamandas AC, Tsiaoussis GI, Karatza E, Zisimopoulos D, Maroulis I, Kontogeorgou E, Georgiou CD, Scopa CD, Thomopoulos KC. Intestinal mucosal proliferation, apoptosis and oxidative stress in patients with liver cirrhosis. Ann Hepatol 2013; 12:301-7. [PMID: 23396742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Intestinal mucosal barrier dysfunction in liver cirrhosis and its implicated mechanisms is of great clinical importance because it is associated with the development of serious complications from diverse organs through promotion of systemic endotoxemia. AIM The present study was designed to investigate whether enterocytes' proliferation, apoptosis and intestinal oxidative stress are altered in the intestinal mucosa of patients with compensated and decompensated liver cirrhosis. MATERIAL AND METHODS Twelve healthy controls (group A) and twenty four cirrhotic patients at a compensated (n = 12, group B) or decompensated condition (n = 12, group C) were subjected to duodenal biopsy. In intestinal specimens mucosal apoptotic and mitotic activity and their ratio were recorded by means of morphological assessment and mucosal lipid hydroperoxides were measured. Plasma endotoxin concentration, an index of gut barrier function, was also determined. RESULTS Cirrhotic patients presented significantly higher serum endotoxin concentrations as compared to healthy controls (P < 0.001), whilst endotoxemia was higher in decompensated disease (P < 0.05 vs. compensated cirrhosis). Intestinal mucosal mitotic count was significantly lower in patients with compensated and decompensated cirrhosis compared to controls (P < 0.01, respectively), whilst a trend towards increased apoptosis was recorded. The mitotic/apoptotic ratio was significantly reduced in groups B (P < 0.05) and C (P < 0.01) as compared to controls. Intestinal lipid peroxidation was significantly increased in decompensated cirrhotics (P < 0.001 vs. groups A and B). CONCLUSIONS The present study demonstrates for the first time that human liver cirrhosis is associated with decreased intestinal mucosal proliferation and proliferation/apoptosis ratio even at early stages of cirrhosis and increased intestinal oxidative stress in advanced liver disease.
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Pytharopoulou S, Kournoutou GG, Leotsinidis M, Georgiou CD, Kalpaxis DL. Cadmium versus copper toxicity: insights from an integrated dissection of protein synthesis pathway in the digestive glands of mussel Mytilus galloprovincialis. J Hazard Mater 2013; 260:263-71. [PMID: 23770617 DOI: 10.1016/j.jhazmat.2013.05.031] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Revised: 05/15/2013] [Accepted: 05/17/2013] [Indexed: 05/23/2023]
Abstract
The main purpose of this study was to investigate the impact of metal-mediated stress on the protein-synthesis pathway in mussels. To this end, mussels (Mytilus galloprovincialis) underwent a 15 days exposure to 100 μg/L Cu(2+) or Cd(2+). Both metals, in particular Cd(2+), accumulated in mussel digestive glands and generated a specific status of oxidative-stress. Exposure of mussels to each metal resulted in 40% decrease of the tRNA-aminoacylation efficiency, at the end of exposure. Cu(2+) also caused a progressive loss in the capability of 40S-ribosomal subunits to form 48S pre-initiation complex, which reached 34% of the control at the end of exposure. Other steps of translation underwent less pronounced, but measurable damages. Mussels exposed to Cd(2+) for 5 days presented a similar pattern of translational dysfunctions in digestive glands, but during the following days of exposure the ribosomal efficiency was gradually restored. Meanwhile, metallothionein levels significantly increased, suggesting that upon Cd(2+)-mediated stress the protein-synthesizing activity was reorganized both quantitatively and qualitatively. Conclusively, Cd(2+) and Cu(2+) affect translation at several levels. However, the pattern of translational responses differs, largely depending on the capability of each metal to affect cytotoxic pathways in the tissues, such as induction of antioxidant defense and specific repair mechanisms.
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Affiliation(s)
- S Pytharopoulou
- Laboratory of Biochemistry, School of Medicine, University of Patras, 26504 Patras, Greece
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Alakhras RS, Stephanou G, Demopoulos NA, Grintzalis K, Georgiou CD, Nikolaropoulos SS. DNA fragmentation induced by all-trans retinoic acid and its steroidal analogue EA-4 in C2 C12 mouse and HL-60 human leukemic cells in vitro. J Appl Toxicol 2013; 34:885-92. [PMID: 23913437 DOI: 10.1002/jat.2908] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 06/04/2013] [Accepted: 06/11/2013] [Indexed: 11/10/2022]
Abstract
We have recently shown that retinoic acid induces micronucleation mainly via chromosome breakage (Alakhras et al. Cancer Lett 2011; 306: 15-26). To further study retinoic acid clastogenicity and evaluate DNA damaging potential we investigated the ability of (a) all-trans retinoic acid and its steroidal analogue EA-4 to induce DNA fragmentation by using Comet assay under alkaline unwinding and neutral condition electrophoresis, and (b) the retinoids under study to induce small (0-1 kb) DNA fragments. Two cell lines, C2C12 mouse cells and HL-60 human leukemic cells were used in this study. We found that all-trans retinoic acid and its steroidal analogue EA-4 (a) provoke DNA migration due to DNA fragmentation as it is shown by the increased values of Comet parameters, and (b) induce significantly small-size fragmented genomic DNA as indicated by the quantification of necrotic/apoptotic small DNA segments in both cell systems. A different response between the two cell lines was observed in relation to retinoid ability to increase the percentage of DNA in the tail as well as break DNA in to small fragments. Our findings confirm the ability of retinoic acid to provoke micronucleation by disrupting DNA into fragments, among which small pieces of double-stranded DNA up to 1 kb are identified.
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Affiliation(s)
- Raghda S Alakhras
- Division of Genetics, Cell and Developmental Biology, Department of Biology, University of Patras, 26 500, Patras, Greece
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Pytharopoulou S, Kournoutou GG, Leotsinidis M, Georgiou CD, Kalpaxis DL. Dysfunctions of the translational machinery in digestive glands of mussels exposed to mercury ions. Aquat Toxicol 2013; 134-135:23-33. [PMID: 23537583 DOI: 10.1016/j.aquatox.2013.02.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2013] [Revised: 02/20/2013] [Accepted: 02/26/2013] [Indexed: 06/02/2023]
Abstract
Mercury is an element naturally occurring in the biosphere, but is also released into the environment by human activities, such as mining, smelting, and industrial discharge. Mercury is a biologically harmful element and any exposure of living organisms mainly due to contamination, can cause severe or even lethal side effects. In every form detected, elemental, inorganic, or organic, mercury exhibits toxicity associated with induced oxidative stress. Although the genotoxicity of mercury has been well demonstrated in mussels, little is known about its toxic effects on the translational machinery at the molecular level. To investigate possible effects, we exposed the common mussel Mytilus galloprovincialis in seawater supplemented by 30 μg/L Hg²⁺ for 15 days. We observed that Hg²⁺ was significantly accumulated in the digestive glands of mussels, reaching a level around 80 μg/g tissue (dry weight) at the 15th day of exposure. Exposure of mussels to Hg²⁺ resulted in failure of redox homeostasis, as reflected on lipid peroxidation levels and superoxide dismutase activity in glands, and micronucleus frequency in gills. Extracts from digestive glands after 15-day exposure to Hg²⁺ exhibited decreased tRNA aminoacylation ability and, moreover, a 70% reduction in the ability of 40S ribosomal subunits to form the 48S initiation ribosomal complex. A similar reduction was detected in the ability of ribosomes to translocate peptidyl-tRNA from the A-site to the P-site, an observation coinciding with the notion that regulation of protein synthesis by Hg²⁺ mainly occurs at the initiation and elongation stages of translation. A-site binding, peptidyl transferase activity, and termination of peptide chain synthesis underwent less pronounced but measurable reductions, a finding which explains why poly(Phe)-synthesis in ribosomes isolated from exposed mussels is reduced by 70%. In conclusion, Hg²⁺ apart from being a genotoxic ion acts as a modulator of protein synthesis in mussels, an observation probably related with its ability to induce oxidative stress.
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Affiliation(s)
- Sofia Pytharopoulou
- Laboratory of Biochemistry, School of Medicine, University of Patras, 26504 Patras, Greece
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Grintzalis K, Zisimopoulos D, Grune T, Weber D, Georgiou CD. Method for the simultaneous determination of free/protein malondialdehyde and lipid/protein hydroperoxides. Free Radic Biol Med 2013; 59:27-35. [PMID: 23041350 DOI: 10.1016/j.freeradbiomed.2012.09.038] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Revised: 09/25/2012] [Accepted: 09/27/2012] [Indexed: 11/21/2022]
Abstract
A simple and sensitive method is presented for the simultaneous quantification (spectrophotometric and spectrofluorimetric) of the main lipid and protein peroxidation products after their initial fractionation: free malondialdehyde (FrMDA), protein-bound malondialdehyde (PrMDA), total hydroperoxides (LOOH), and protein hydroperoxides (PrOOH). FrMDA and PrMDA (released from proteins by alkaline hydrolysis) are measured after the reaction of MDA with thiobarbituric acid (TBA) under acidic conditions, by the specific fluorimetric quantification of the resulting MDA-(TBA)2 adduct chromophore. The measurement of LOOH and PrOOH is based on the reaction of Fe(3+) (resulting from the reaction of LOOH and PrOOH with Fe(2+)) with xylenol orange (XO) and the photometric quantification of the resulting XO-Fe complex. The sensitivity of the assays for FrMDA/PrMDA and LOOH/PrOOH is 20 and 100pmol, respectively. The method was applied successfully on human plasma and can be used for the evaluation of oxidative stress in both basic and clinical research.
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Affiliation(s)
- Konstantinos Grintzalis
- Genetics, Cell, and Developmental Biology Section, Department of Biology, University of Patras, Patras 26100, Greece
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Grintzalis K, Georgiou CD, Dailianis S. Total thiol redox status as a potent biomarker of PAH-mediated effects on mussels. Mar Environ Res 2012; 81:26-34. [PMID: 22944588 DOI: 10.1016/j.marenvres.2012.08.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Revised: 07/27/2012] [Accepted: 08/03/2012] [Indexed: 06/01/2023]
Abstract
This laboratory study describes phenanthrene (Ph) and/or anthracene (An) ability to alter the total thiol redox status (TRS), via depletion of protein free thiols (PSH) and glutathione (GSH) levels, in gills of mussel Mytilus galloprovincialis, after a short-term (7 days) exposure period to each contaminant (at a final concentration of 0.1 mg L(-1)) or in a mixture (ration 1:1, at a final concentration of 0.2 mg L(-1)). A number of observable changes, like lysosomal membrane impairment (as detected via the neutral red retention time assay, primarily performed in haemocytes), enhancement of lipid peroxidation byproducts, increased nuclear abnormalities, inhibition of AChE and ALP activity, as well as a significant depletion of PSH and GSH were detected in gills of exposed mussels, in any case. Significant relationships occurred among TRS parameters with each change/stress indices measured in tissues of mussels, could reinforce the use of PSH as a potent biomarker.
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Affiliation(s)
- Konstantinos Grintzalis
- Department of Biology, Section of Genetics, Cell Biology and Development, University of Patras, Patras, Greece
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Pytharopoulou S, Grintzalis K, Sazakli E, Leotsinidis M, Georgiou CD, Kalpaxis DL. Translational responses and oxidative stress of mussels experimentally exposed to Hg, Cu and Cd: one pattern does not fit at all. Aquat Toxicol 2011; 105:157-165. [PMID: 21718659 DOI: 10.1016/j.aquatox.2011.06.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Revised: 05/31/2011] [Accepted: 06/03/2011] [Indexed: 05/31/2023]
Abstract
Certain metals, like Hg, Cu and Cd, are capable of down-regulating protein synthesis in several marine organisms, including Mytilus galloprovincialis. Nevertheless, due to the complexity of the environmental stress, it is difficult to evaluate the influence of individual metals on protein synthesis via field studies. To bypass this difficulty, experimental studies were carried out on M. galloprovincialis exposed in aquarium for 15 days to one of three selected metal salts, HgCl(2), CuCl(2) and CdCl(2). Polysome profile was determined in digestive gland extracts of the exposed mussels as a way of measuring the functional status of ribosomes, superoxide radical production and lipid peroxidation as indicators of oxidative stress, metallothionein content as a metal detoxification index, and superoxide dismutase activity as a free radicals-scavenging index. Exposure of mussels to Hg(2+) or Cu(2+) resulted in a concentration- and time-dependent decrease in the polysome content of digestive gland cells, which at 15th day of exposure and at the highest metal concentrations tested, was 32% and 19% of the control, respectively. Both metals, at the concentrations used (<40 μg/L), did not significantly influence the oxidative stress biomarkers. By contrast, Cd(2+) treatment significantly induced superoxide radical production and lipid peroxidation in digestive gland cells, hinting that mussels suffered from oxidative stress. Polysome levels in Cd(2+)-exposed mussels were initially decreased by day 5 in digestive gland cells and then elevated to reach nearly the control levels by 15 days of exposure. Elevated protein synthesis was associated with significantly increased production of metallothioneins, whereas such increase was not recorded in Hg(2+)- or Cu(2+)-exposed mussels. Interestingly, the ribosome efficiency at initiating protein synthesis followed a similar pattern of polysome alterations, a fact suggesting that regulation of protein synthesis mainly occurred at the initiation phase of translation. Overall, these results suggest that the effect of each metal on protein synthesis is idiosyncratic and depends on its ability to induce specific cellular defense mechanisms against oxidative stress.
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Affiliation(s)
- Sofia Pytharopoulou
- Laboratory of Biochemistry, School of Medicine, University of Patras, 26504 Patras, Greece
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Abstract
AIMS The purpose of this study was to investigate the role of H(2) O(2) and the related oxidative stress markers catalase (CAT) and lipid peroxidation in the sclerotial differentiation of the phytopathogenic filamentous fungi Sclerotium rolfsii, Sclerotinia minor, Sclerotinia sclerotiorum and Rhizoctonia solani. METHODS AND RESULTS Using the H(2) O(2) -specific scopoletin fluorometric assay and the CAT-dependent H(2) O(2) consumption assays, it was found that the production rate of intra/extracellular H(2) O(2) and CAT levels in the sclerotiogenic fungi were significantly higher and lower, respectively, than those of their nondifferentiating counterpart strains. They peaked in the transition between the undifferentiated and the differentiated state of the sclerotiogenic strains, suggesting both a cell proliferative and differentiative role. In addition, the indirect indicator of oxidative stress, lipid peroxidation, was substantially decreased in the nondifferentiating strains. CONCLUSIONS These findings suggest that the differentiative role of H(2) O(2) is expressed via induction of higher oxidative stress in the sclerotiogenic filamentous phytopathogenic fungi. SIGNIFICANCE AND IMPACT OF THE STUDY This study shows that the direct marker of oxidative stress H(2) O(2) is involved in the sclerotial differentiation of the phytopathogenic filamentous fungi S. rolfsii, S. minor, S. sclerotiorum and R. solani, which could have potential biotechnological implications in terms of developing antifungal strategies by regulating intracellular H(2) O(2) levels.
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Affiliation(s)
- I Papapostolou
- Department of Biology, Section of Genetics, Cell Biology and Development, University of Patras, Patras, Greece
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Panteli ES, Fligou F, Papamichail C, Papapostolou I, Zervoudakis G, Georgiou CD, Filos KS. Quantification of superoxide radical production in 4 vital organs of rats subjected to hemorrhagic shock. Am J Emerg Med 2011; 30:476-80. [PMID: 21354748 DOI: 10.1016/j.ajem.2010.12.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Revised: 12/14/2010] [Accepted: 12/23/2010] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVE The aim of this study was to measure the production of superoxide radical (O2-), a direct indicator of oxidative stress, in 4 vital organs of rats subjected to hemorrhagic shock. For this purpose, and for the first time, a new quantitative assay for the ex vivo measurement of O2- via an established 1:1 molar relationship between O2- and 2-OH-ethidium was used. The production of lipid hydroperoxides (LOOHs), a standard method of evaluation of oxidative stress, was also used for reasons of comparison. METHODS Sixteen male Wistar rats were divided into 2 groups: sham and hemorrhagic shock, targeting to a mean arterial pressure of 30 to 40 mm Hg for 60 minutes. Three hours after resuscitation, tissues were collected for measurement of LOOHs and O2- production. RESULTS Hemorrhagic shock induced increased production of LOOHs in the gut, liver, and lungs (P<.001), whereas the production of O2- was also increased in the gut (P<.001), liver (P<.001), and, to a lesser extent, in the lungs (P<.05). The oxidative load of the kidneys, as estimated by both techniques, remained unaffected. CONCLUSION The results of this new O2- assay were comparable with the results of the established LOOHs method, and this assay proved to be accurate and sensitive in the detection and quantification of O2- production in all organs tested. Thus, the proposed direct measurement of O2- in critically ill patients often facing in extremis situations could be used as a prognostic tool and as a method to evaluate therapeutic interventions in the setting of emergency medicine.
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Affiliation(s)
- Eleftheria S Panteli
- Department of Anesthesiology and Critical Care Medicine, School of Medicine, 26500 Rion, Greece
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Assimakopoulos SF, Tsamandas AC, Georgiou CD, Vagianos CE, Scopa CD. Bombesin and neurotensin exert antiproliferative effects on oval cells and augment the regenerative response of the cholestatic rat liver. Peptides 2010; 31:2294-303. [PMID: 20833216 DOI: 10.1016/j.peptides.2010.09.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Revised: 09/02/2010] [Accepted: 09/02/2010] [Indexed: 12/30/2022]
Abstract
The regenerative capacity of the cholestatic liver is significantly attenuated. Oval cells are hepatic stem cells involved in liver's regeneration following diverse types of injury. The present study investigated the effect of the neuropeptides bombesin (BBS) and neurotensin (NT) on oval cell proliferation as well as on hepatocyte and cholangiocyte proliferation and apoptosis in the cholestatic rat liver. Seventy male Wistar rats were randomly divided into five groups: controls, sham operated, bile duct ligated (BDL), BDL+BBS (30 μg/kg/d), BDL+NT (300 μg/kg/d). Ten days later, alpha-fetoprotein (AFP) mRNA (in situ hybridization), cytokeratin-19 and Ki67 antigen expression (immunohistochemistry) and apoptosis (TUNEL) were evaluated on liver tissue samples. Cells with morphologic features of oval cells that were cytokeratin-19(+) and AFP mRNA(+) were scored in morphometric analysis and their proliferation was recorded. In addition, the proliferation and apoptotic rates of hepatocytes and cholangiocytes were determined. Alanine aminotransferase (ALT) levels and hepatic oxidative stress (lipid peroxidation and glutathione redox state) were also estimated. The neuropeptides BBS and NT significantly reduced ALT levels and hepatic oxidative stress. Both agents exerted similar and cell type-specific effects on oval cells, hepatocytes and cholangiocytes: (a) oval cell proliferation and accumulation in the cholestatic liver was attenuated, (b) hepatocyte proliferation was increased along with a decreased rate of their apoptosis and (c) cholangiocyte proliferation was attenuated and their apoptosis was increased. These observations might be of potential value in patients with extrahepatic cholestasis.
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Papapostolou I, Georgiou CD. Superoxide radical is involved in the sclerotial differentiation of filamentous phytopathogenic fungi: identification of a fungal xanthine oxidase. Fungal Biol 2010; 114:387-95. [PMID: 20943149 DOI: 10.1016/j.funbio.2010.01.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2009] [Revised: 12/13/2009] [Accepted: 01/31/2010] [Indexed: 11/19/2022]
Abstract
This study shows that the direct indicator of oxidative stress superoxide radical (O·₂⁻) is involved in the sclerotial differentiation of the phytopathogenic filamentous fungi Rhizoctonia solani, Sclerotinia sclerotiorum, Sclerotium rolfsii, and Sclerotinia minor. The production rate of O·₂⁻ and the antioxidant enzyme superoxide dismutase (SOD) levels in the sclerotiogenic fungi were significantly higher and lower, respectively, than those of their non-differentiating counterpart strains, which strongly suggests that the oxidative stress of the sclerotium differentiating fungi is higher than that of the non-differentiating ones. Xanthine oxidase (XO), which was detected for the first time in fungi in general, was localized in the cytoplasmic membrane. The contribution of XO in the overall O·₂⁻production was very significant, reaching 30-70% among the strains, especially in the transition developmental stage between the undifferentiated and the differentiated state, suggesting a sclerotium triggering and a phytopathogenic role of XO during plant infection. The additional finding that these fungi secrete extracellular SOD can be related to their protection from the response of plants to produce O·₂⁻ at infection sites.
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Affiliation(s)
- Ioannis Papapostolou
- Department of Biology, Section of Genetics, Cell Biology and Development, University of Patras, 26100 Patras, Greece
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Faropoulos K, Chroni E, Assimakopoulos SF, Mavrakis A, Stamatopoulou V, Toumpeki C, Drainas D, Grintzalis K, Papapostolou I, Georgiou CD, Konstantinou D. Altered occludin expression in brain capillaries induced by obstructive jaundice in rats. Brain Res 2010; 1325:121-7. [PMID: 20170644 DOI: 10.1016/j.brainres.2010.02.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2009] [Revised: 01/30/2010] [Accepted: 02/04/2010] [Indexed: 11/18/2022]
Abstract
The development of increased oxidative stress in the context of obstructive cholestasis has been proven in various rats' organs including the brain. The present study aimed to detect alterations of tight junction-associated occludin in rat brain capillaries after bile duct ligation (BDL). In experiment 1, occludin expression was evaluated by Western blot analysis in 5 animals 10 days after BDL and compared with 5 sham-operated ones. In experiment 2, groups of 9 animals each were used to assess occludin levels on the 1st, 5th, and 10th days after BDL and to associate these measurements with the in vivo superoxide radical production measured by means of an ultrasensitive fluorescent assay. The results indicated that occludin expression in BDL animals, as opposed to sham-operated, was significantly reduced at every time point studied, being lowest in the rats remaining on BDL condition for 10 days. Moreover, it was demonstrated that the time-dependent downregulation of occludin expression in the brain endothelial was significantly correlated with the time-dependent increase of brain superoxide radical level, implying a relationship between these two abnormalities. In conclusion, the evidence presented herein suggests the implication of occludin and, therefore, of blood-brain barrier in the pathophysiology of extrahepatic cholestasis.
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Affiliation(s)
- Konstantinos Faropoulos
- Department of Neurosurgery, School of Medicine, Division of Genetics, Cell and Developmental Biology, University of Patras, Patras, Greece
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Chronidou F, Apostolakis E, Papapostolou I, Grintzalis K, Georgiou CD, Koletsis EN, Karanikolas M, Papathanasopoulos P, Dougenis D. Beneficial effect of the oxygen free radical scavenger amifostine (WR-2721) on spinal cord ischemia/reperfusion injury in rabbits. J Cardiothorac Surg 2009; 4:50. [PMID: 19758462 PMCID: PMC2751753 DOI: 10.1186/1749-8090-4-50] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2009] [Accepted: 09/17/2009] [Indexed: 11/10/2022] Open
Abstract
Background Paraplegia is the most devastating complication of thoracic or thoraco-abdominal aortic surgery. During these operations, an ischemia-reperfusion process is inevitable and the produced radical oxygen species cause severe oxidative stress for the spinal cord. In this study we examined the influence of Amifostine, a triphosphate free oxygen scavenger, on oxidative stress of spinal cord ischemia-reperfusion in rabbits. Methods Eighteen male, New Zealand white rabbits were anesthetized and spinal cord ischemia was induced by temporary occlusion of the descending thoracic aorta by a coronary artery balloon catheter, advanced through the femoral artery. The animals were randomly divided in 3 groups. Group I functioned as control. In group II the descending aorta was occluded for 30 minutes and then reperfused for 75 min. In group III, 500 mg Amifostine was infused into the distal aorta during the second half-time of ischemia period. At the end of reperfusion all animals were sacrificed and spinal cord specimens were examined for superoxide radicals by an ultra sensitive fluorescent assay. Results Superoxide radical levels ranged, in group I between 1.52 and 1.76 (1.64 ± 0.10), in group II between 1.96 and 2.50 (2.10 ± 0.23), and in group III (amifostine) between 1.21 and 1.60 (1.40 ± 0.19) (p = 0.00), showing a decrease of 43% in the Group of Amifostine. A lipid peroxidation marker measurement ranged, in group I between 0.278 and 0.305 (0.296 ± 0.013), in group II between 0.427 and 0.497 (0.463 ± 0.025), and in group III (amifostine) between 0.343 and 0.357 (0.350 ± 0.007) (p < 0.00), showing a decrease of 38% after Amifostine administration. Conclusion By direct and indirect methods of measuring the oxidative stress of spinal cord after ischemia/reperfusion, it is suggested that intra-aortic Amifostine infusion during spinal cord ischemia phase, significantly attenuated the spinal cord oxidative injury in rabbits.
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Affiliation(s)
- Fany Chronidou
- Cardiothoracic Surgery Department, Medical School, University of Patras, Patras, Greece.
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Gartaganis SP, Georgakopoulos CD, Patsoukis NE, Gotsis SS, Gartaganis VS, Georgiou CD. Glutathione and Lipid Peroxide Changes in Pseudoexfoliation Syndrome. Curr Eye Res 2009; 30:647-51. [PMID: 16109644 DOI: 10.1080/02713680590968367] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
PURPOSE To investigate the oxidative status of the aqueous humor of patients with pseudoexfoliation (PEX) syndrome. METHODS Aqueous humor samples obtained during cataract surgery of patients with PEX syndrome and normal age-matched control subjects were examined for changes in the levels of glutathione (GSH), glutathione disulfide (GSSG), and TBA reactive species (TBARS), products of lipid peroxidation. GSH, GSSG, and TBARS were determined by specific fluorescent assays. RESULTS Compared to normal controls, PEX syndrome aqueous humor samples showed a decrease of up to 28% of GSH concentration, and GSSG was increased up to 23%. The ratio of GSH/GSSG was 1.7-fold decreased in PEX syndrome samples. TBARS levels were increased by 100% in the PEX aqueous humor samples as compared to the controls. CONCLUSIONS High levels of GSSG and TBARS indicate high oxidative stress, as well as the decrease in the ratio of GSH/GSSG. Our findings suggest a role for oxidation stress in the pathogenesis and the progression of PEX syndrome.
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Affiliation(s)
- S P Gartaganis
- Department of Ophthalmology, School of Medicine, University of Patras, Patras, Greece.
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Georgiou CD, Papapostolou I, Grintzalis K. Protocol for the quantitative assessment of DNA concentration and damage (fragmentation and nicks). Nat Protoc 2009; 4:125-31. [PMID: 19180084 DOI: 10.1038/nprot.2008.222] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
An ultrasensitive protocol is presented for the quantitative assessment of fragmented and nicked dsDNA using PicoGreen and consists of four methods. The first quantifies the concentration of DNA, whereas the second (quantitative complement of the Comet assay) quantifies the degree of DNA fragmentation seen in a typical DNA agarose electrophoresis gel. Both methods have sensitivity of 5 pg of DNA. The third method (quantitative counterpart of the electrophoresis-based qualitative apoptotic and necrotic DNA assays) quantifies the polyethylene glycol-fractionated small-size (0-1 kb) fragmented DNA. This method also detects up to 5 pg of damaged DNA and requires a minimum sample of quantity 0.2 ml of 2.5 microg ml(-1). The fourth method measures the percentage of DNA nicks by alkaline DNA unwinding and requires up to 15 pg of DNA sample. The time required for processing 10 DNA samples is 1/2, 1, 13 and 1 h for the first, second, third and fourth method, respectively.
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Affiliation(s)
- Christos D Georgiou
- Department of Biology, Section of Genetics, Cell Biology and Development, University of Patras, 26100-Patras, Greece.
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Assimakopoulos SF, Grintzalis K, Papapostolou I, Thomopoulos KC, Georgiou CD. Increased Plasma Superoxide Radical in Patients with Non-Metastatic Colorectal Cancer. Gastroenterology Res 2008; 1:45-48. [PMID: 27994706 PMCID: PMC5154215 DOI: 10.4021/gr2008.11.1249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2008] [Accepted: 11/30/2008] [Indexed: 11/08/2022] Open
Abstract
Background Several studies have investigated the potential role of oxidative stress in the evolution of colorectal cancer. In most of these studies, oxidative stress was assessed indirectly by measurements of indices like lipid peroxidation, protein oxidation or antioxidant status. The present study was undertaken to directly assess systemic oxidative stress by measuring plasma superoxide radical (O2-·) in patients with non-metastatic colorectal cancer. Methods Twelve patients (6 males and 6 females) with a recent diagnosis of colorectal cancer and no signs of metastases and 12 healthy volunteers matched for age and gender were enrolled in the study. O2-· levels in plasma were assessed by application of a new ultra-sensitive fluorescent assay. Also lipid peroxidation levels in plasma were measured as thiobarbituric acid reactive species (TBARS). Results In the plasma fraction of whole blood, there was a significant increase (47%) of O2-· levels in colorectal carcinoma patients as compared to healthy volunteers (P < 0.001). In fractionated plasma, no O2-· was detected in both groups. Plasma TBARS levels were increased by 81% in colorectal carcinoma patients as compared to controls (P < 0.001). Conclusions These data show that colorectal cancer, even at early (non-metastatic) stages, induces systemic oxidative stress as evidenced by increased O2·- levels measured in plasma. Given the important role of oxidative stress in carcinogenesis and the fact that O2·- is considered its primary parameter, our findings if confirmed in larger studies might establish the potential validity of O2·- as a new biomarker for colorectal cancer.
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Affiliation(s)
| | - Konstantinos Grintzalis
- Section of Genetics, Cell and Developmental Biology, Department of Biology, University of Patras, Patras, Greece
| | - Ioannis Papapostolou
- Section of Genetics, Cell and Developmental Biology, Department of Biology, University of Patras, Patras, Greece
| | - Konstantinos C Thomopoulos
- Division of Gastroenterology, Department of Internal Medicine, University Hospital of Patras, Patras 26504, Greece
| | - Christos D Georgiou
- Section of Genetics, Cell and Developmental Biology, Department of Biology, University of Patras, Patras, Greece
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Fakas S, Papapostolou I, Papanikolaou S, Georgiou CD, Aggelis G. Susceptibility to peroxidation of the major mycelial lipids of Cunninghamella echinulata. EUR J LIPID SCI TECH 2008. [DOI: 10.1002/ejlt.200800025] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Pytharopoulou S, Sazakli E, Grintzalis K, Georgiou CD, Leotsinidis M, Kalpaxis DL. Translational responses of Mytilus galloprovincialis to environmental pollution: integrating the responses to oxidative stress and other biomarker responses into a general stress index. Aquat Toxicol 2008; 89:18-27. [PMID: 18599131 DOI: 10.1016/j.aquatox.2008.05.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2008] [Revised: 05/20/2008] [Accepted: 05/22/2008] [Indexed: 05/04/2023]
Abstract
Heavy metals are commonly associated with the generation of reactive oxygen species (ROS), which may cause oxidative damage to several cellular macromolecules and organelles. In an attempt to correlate biomarker responses to oxidative stress, caged mussels (Mytilus galloprovincialis) were exposed for 30 days in a relatively clean site and two areas (Stations 1 and 2) unevenly polluted by heavy metals in Gulf of Patras (Greece). Three periods of caging were: one in winter, the second in spring, and the third in autumn. Heavy metal content was determined in digestive glands of the exposed mussels as a measure of metal pollution, metallothionein content as an adaptive and detoxifying index, lysosomal membrane stability as a biomarker of general stress, superoxide radical production and lipid peroxidation as indicators of oxidative stress, and micronucleus frequency in gill cells as an index of chromosomal damage. Considering that protein-synthesizing machinery is one of the candidate targets for ROS, the in vivo activity of ribosomes in digestive glands was also tested. Compared with the reference samples, mussels transplanted to Station 1 showed increased levels of heavy metals and metallothionein in digestive glands, lower lysosomal membrane stability, higher values in oxidative stress indices, reduced activity of ribosomes, and increased chromosomal damage in gill cells. In addition, run-off ribosomes isolated from mussels transplanted to Station 1 were less efficient at initiating protein synthesis in a cell-free system than those from mussels in the reference site. Mussels transplanted to Station 2 exhibited similar but less pronounced responses. Statistical analysis revealed a strong positive correlation of ribosomal activity with lysosomal membrane stability, as well as a significant negative correlation with the oxidative stress indices, metallothionein content, micronucleus frequency, and the digestive gland content in Cr, Cu and Mn. Integration of all the measured biomarker responses into one general "stress index" demonstrated a clear distinction between the sampling sites, allowing classification along a pollution gradient (reference site<Station 2<Station 1), independently from the season. Moreover, this analysis allowed us to compare responses between sampling campaigns and showed that the biomarker responses show best integration in winter. It was also evident that climatic or metabolic changes could modulate bioavailability of pollutants and priming of cellular defence processes.
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Affiliation(s)
- Sofia Pytharopoulou
- Laboratory of Biochemistry, School of Medicine, University of Patras, 26504 Patras, Greece
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Abstract
Sclerotial differentiation in Sclerotinia minor is associated with oxidative stress and thiol redox state. The significance of oxidative stress to sclerotial differentiation was revealed by the higher oxidative stress of S. minor compared with a nonsclerotiogenic counterpart. The effect of thiol redox state on sclerotial differentiation was shown by the antioxidant action of the thiol (-SH) group of N-acetylcysteine and cysteine and by an unknown (not antioxidant) role of glutathione (GSH) on S. minor. The nonantioxidant role of GSH was indicated by the differentiation-inhibiting and differentiation-noninhibiting actions of the GSH biosynthesis inhibitor L-buthionine-S,R-sulfoximine and the GSH biosynthesis inducer L-2-oxo-thiazolidine-4-carboxylate, respectively, and by the increase of oxidative stress they caused during the transition from the undifferentiated to differentiated state of S. minor. Moreover, N-acetylcysteine can be used as a potent nontoxic fungicide against this phytopathogenic fungus by acting as a growth-inhibiting cytotoxic oxidant and by sustaining the fungus in the undifferentiated hyphal stage, which is vulnerable to degradation by soil microorganisms.
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Affiliation(s)
- Nikolaos Patsoukis
- Department of Biology, Section of Genetics, Cell Biology and Development, University of Patras, 26100-Patras, Greece
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Assimakopoulos SF, Maroulis I, Patsoukis N, Vagenas K, Scopa CD, Georgiou CD, Vagianos CE. Effect of antioxidant treatments on the gut-liver axis oxidative status and function in bile duct-ligated rats. World J Surg 2007; 31:2023-32. [PMID: 17665241 DOI: 10.1007/s00268-007-9191-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND Experimental and clinical studies have demonstrated the pivotal role of oxidative stress in the promotion of hepatic and intestinal injury in obstructive jaundice. The present study was undertaken to investigate the effect of well known antioxidant treatments on the gut-liver axis oxidative status and function in bile duct-ligated rats. METHODS A total of 60 male Wistar rats were randomly divided into six groups of 10 animals each: controls, sham operated, bile duct ligated (BDL), and BDL treated with either N-acetylcysteine (NAC), allopurinol, or alpha-tocopherol (alpha-TC). Ten days after treatment, the hepatic and intestinal oxidative status was estimated by measuring lipid peroxidation and a battery of biochemical markers comprising the organ's thiol redox state (i.e., glutathione, cysteine, protein thiols, oxidized glutathione, nonprotein mixed disulfides, oxidized cysteine derivatives, protein symmetrical disulfides, and protein mixed disulfides). Portal and aortic endotoxin concentrations and alanine aminotransferase (ALT) levels were also determined. RESULTS All antioxidant treatments significantly improved intestinal barrier function and protected from cholestatic liver injury, as evidenced by reduction of the portal and aortic endotoxin concentration and ALT levels, respectively. This effect accompanied their significant antioxidant action in both organs, mediated by a certain influence profile on the thiol redox state by each treatment. CONCLUSION NAC, allopurinol, and alpha-TC, exerting a potent combined antioxidant effect on the intestine and liver in experimental obstructive jaundice, significantly prevented intestinal barrier dysfunction and liver injury. The variety of results depending on the antioxidant agent that was administered and the marker of oxidative stress that was estimated, indicates that a battery of biomarkers would be more appropriate in assessing pharmacologic responses to therapeutic interventions.
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Patsoukis N, Georgiou CD. Thiol redox state and oxidative stress affect sclerotial differentiation of the phytopathogenic fungi Sclerotium rolfsii and Sclerotinia sclerotiorum. J Appl Microbiol 2007; 104:42-50. [PMID: 17850300 DOI: 10.1111/j.1365-2672.2007.03527.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
AIMS To investigate the involvement of oxidative stress and thiol redox state (TRS) in sclerotial differentiation of Sclerotium rolfsii and Sclerotinia sclerotiorum. METHODS AND RESULTS Oxidative stress in these fungi was assessed by lipid peroxidation, which was higher in comparison with their nonsclerotiogenic counterpart strains. TRS [measured as glutathione (GSH) and cysteine] was associated with oxidative stress and differentiation using the TRS modulator and antioxidant Nu-acetylcysteine (AcCSH) and the GSH biosynthesis inducer and inhibitor l-2-oxo-thiazolidine-4-carboxylate and L-buthionine-S,R-sulphoximine (BSO) respectively. Differentiation and oxidative stress was decreased by AcCSH in both fungi. The decrease of differentiation by BSO was not associated with oxidative stress in these fungi. CONCLUSIONS Differentiation and oxidative stress in both fungi depends on the availability of antioxidant noncytotoxic -SH groups and is not depended on any direct antioxidant role of GSH and its precursor cysteine. SIGNIFICANCE AND IMPACT OF THE STUDY This study helps to understand the mechanism(s) of sclerotial differentiation in these agriculturally important phytopathogenic fungi and proposes that AcCSH can be used as potent fungicide by (i) acting as growth inhibiting cytotoxic oxidant and (ii) sustaining these fungi in their undifferentiated hyphal stage where they are vulnerable to degradation by soil micro-organisms.
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Affiliation(s)
- N Patsoukis
- Department of Biology, Section of Genetics, Cell Biology and Development, University of Patras, Patras, Greece
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