1
|
Tonis E, Frousiou E, Heliopoulos NS, Kagkoura A, Stangel C, Siamidis D, Galeou A, Prombona A, Stamatakis K, Boukos N, Tagmatarchis N, Vougioukalakis GC. VAR Fabric Modification: Inducing Antibacterial Properties, Altering Wettability/Water Repellence, and Understanding Reactivity at the Molecular Level. ACS Omega 2023; 8:44708-44716. [PMID: 38046315 PMCID: PMC10688117 DOI: 10.1021/acsomega.3c05552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Accepted: 09/19/2023] [Indexed: 12/05/2023]
Abstract
The present work focuses on the surface coating of VAR technical fibers, consisting of 64% viscose (cellulose), 24% Kevlar, 10% other types of polyamides, and 2% antistatic polymers. Kevlar is an aramid material exhibiting excellent mechanical properties, while cellulose is a natural linear polymer composed of repeating β-d-glucose units, having several applications in the materials industry. Herein, we synthesized novel, tailor-designed organic molecules possessing functional groups able to anchor on VAR fabrics and cellulose materials, thus altering their properties on demand. To this end, we utilized methyl-α-d-glucopyranose as a model compound, both to optimize the reaction conditions, before applying them to the material and to understand the chemical behavior of the material at the molecular level. The efficient coating of the VAR fabric with the tailor-made compounds was then implemented. Thorough characterization studies using Raman and IR spectroscopies as well as SEM imaging and thermogravimetric analysis were also carried out. The wettability and water repellency and antibacterial properties of the modified VAR fabrics were also investigated in detail. To the best of our knowledge, such an approach has not been previously explored, among other factors regarding the understanding of the anchoring mechanism at the molecular level. The proposed modification protocol holds the potential to improve the properties of various cellulose-based materials beyond VAR fabrics.
Collapse
Affiliation(s)
- Efstathios Tonis
- Laboratory of Organic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Athens 15771, Greece
| | - Efrosyni Frousiou
- Laboratory of Organic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Athens 15771, Greece
| | - Nikolaos S Heliopoulos
- 700 Military Factory, Supreme Military Support Command, 50 Anapafseos, Piraeus 18648, Greece
| | - Antonia Kagkoura
- Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, Athens 11635, Greece
| | - Christina Stangel
- Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, Athens 11635, Greece
| | | | - Angeliki Galeou
- Institute of Biosciences and Applications, National Centre for Scientific Research "Demokritos", Patriarchou Grigoriou E' & Neapoleos Str., Agia Paraskevi,Athens, Attica 15341, Greece
| | - Anastasia Prombona
- Institute of Biosciences and Applications, National Centre for Scientific Research "Demokritos", Patriarchou Grigoriou E' & Neapoleos Str., Agia Paraskevi,Athens, Attica 15341, Greece
| | - Kostas Stamatakis
- Institute of Biosciences and Applications, National Centre for Scientific Research "Demokritos", Patriarchou Grigoriou E' & Neapoleos Str., Agia Paraskevi,Athens, Attica 15341, Greece
| | - Nikos Boukos
- Institute of Nanoscience and Nanotechnology, National Centre for Scientific Research "Demokritos", Patriarchou Grigoriou E' & Neapoleos Str., Agia Paraskevi,Athens, Attica 15341, Greece
| | - Nikos Tagmatarchis
- Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, Athens 11635, Greece
| | - Georgios C Vougioukalakis
- Laboratory of Organic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Athens 15771, Greece
| |
Collapse
|
2
|
Frousiou E, Tonis E, Rotas G, Pantelia A, Chalkidis SG, Heliopoulos NS, Kagkoura A, Siamidis D, Galeou A, Prombona A, Stamatakis K, Boukos N, Vougioukalakis GC. Kevlar ®, Nomex ®, and VAR Modification by Small Organic Molecules Anchoring: Transfusing Antibacterial Properties and Improving Water Repellency. Molecules 2023; 28:5465. [PMID: 37513342 PMCID: PMC10385662 DOI: 10.3390/molecules28145465] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 07/08/2023] [Accepted: 07/10/2023] [Indexed: 07/30/2023] Open
Abstract
The surface modification of fabrics composed of Kevlar®, Nomex®, or VAR was extensively investigated. Kevlar® and Nomex® are widely-utilized aramid materials, whereas VAR is a technical fabric comprising 64% viscose, 24% para-aramid (Kevlar®), 10% polyamide, and 2% antistatic fibers. Both aramid materials and cellulose/viscose exhibit exceptional mechanical properties that render them valuable in a wide range of applications. For the herein studied modification of Kevlar®, Nomex®, and VAR, we used small organic molecules 3-allyl-5,5-dimethylhydantoin (ADMH) and 3-(acrylamidopropyl)trimethylammonium chloride (APTAC), which were anchored onto the materials under study via graft polymerization. By doing so, excellent antibacterial properties were induced in the three studied fabrics. Their water repellency was improved in most cases as well. Extensive characterization studies were conducted to probe the properties of the modified materials, employing Raman and FTIR spectroscopies, Scanning Electron Microscopy (SEM), and thermogravimetric analysis (TGA).
Collapse
Affiliation(s)
- Efrosyni Frousiou
- Laboratory of Organic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, 15771 Athens, Greece
| | - Efstathios Tonis
- Laboratory of Organic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, 15771 Athens, Greece
| | - Georgios Rotas
- Laboratory of Organic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, 15771 Athens, Greece
- Laboratory of Organic Chemistry, Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece
| | - Anna Pantelia
- Laboratory of Organic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, 15771 Athens, Greece
| | - Savvas G Chalkidis
- Laboratory of Organic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, 15771 Athens, Greece
| | - Nikolaos S Heliopoulos
- 700 Military Factory, Supreme Military Support Command, 50 Anapafseos, 18648 Piraeus, Greece
| | - Antonia Kagkoura
- Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 11635 Athens, Greece
| | | | - Angeliki Galeou
- Institute of Biosciences and Applications, National Centre for Scientific Research "Demokritos", Patriarchou Grigoriou E' & Neapoleos Str., 15341 Agia Paraskevi Attica, Greece
| | - Anastasia Prombona
- Institute of Biosciences and Applications, National Centre for Scientific Research "Demokritos", Patriarchou Grigoriou E' & Neapoleos Str., 15341 Agia Paraskevi Attica, Greece
| | - Kostas Stamatakis
- Institute of Biosciences and Applications, National Centre for Scientific Research "Demokritos", Patriarchou Grigoriou E' & Neapoleos Str., 15341 Agia Paraskevi Attica, Greece
| | - Nikos Boukos
- Institute of Nanoscience and Nanotechnology, National Centre for Scientific Research "Demokritos", Patriarchou Grigoriou E' & Neapoleos Str., 15341 Agia Paraskevi Attica, Greece
| | - Georgios C Vougioukalakis
- Laboratory of Organic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, 15771 Athens, Greece
| |
Collapse
|
3
|
Perdikaki A, Galeou A, Pilatos G, Prombona A, Karanikolos GN. Ion-Based Metal/Graphene Antibacterial Agents Comprising Mono-Ionic and Bi-Ionic Silver and Copper Species. Langmuir 2018; 34:11156-11166. [PMID: 30145895 DOI: 10.1021/acs.langmuir.8b01880] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Design of novel and more efficient antibacterial agents is a continuous and dynamic process due to the appearance of new pathogenic strains and inherent resistance development to existing antimicrobial treatments. Metallic nanoparticles (NPs) are highly investigated, yet the role of released ions is crucial in the antibacterial activity of the NP-based systems. We developed herein ion-based, metal/graphene hybrid structures comprising surface-bound Ag and Cu mono-ionic and Ag/Cu bi-ionic species on functionalized graphene, without involvement of NPs. The antibacterial performance of the resulting systems was evaluated against Escherichia coli cells using a series of parametrization experiments of varying metal ion types and concentrations and compared with that of the respective NP-based systems. It was found that the bi-ionic Ag/Cu-graphene materials exhibited superior performance compared to that of the mono-ionic analogues owing to the synergistic action of the combination of the two different metal ions on the surface and the enhancing role of the graphene support, whereas all ion-based systems performed superiorly compared to their NP-based counterparts of the same metal type and concentration. In addition, the materials exhibited sustained action, as their activity was maintained after reuse in repeated cycles employing fresh bacteria in each cycle. The systems developed herein may open new prospects toward the development of novel, efficient, and tunable antibacterial agents by properly supporting and configuring metals in ionic form.
Collapse
Affiliation(s)
| | | | | | | | - Georgios N Karanikolos
- Department of Chemical Engineering, The Petroleum Institute , Khalifa University of Science & Technology , P.O. Box 2533, Abu Dhabi , UAE
- Center for Membranes and Advanced Water Technology , Khalifa University of Science & Technology , P.O. Box 127788, Abu Dhabi , UAE
| |
Collapse
|
4
|
Galeou A, Roussis A, Prombona A. Investigation of the Phaseolus vulgaris circadian clock and the repressive role of the PvTOC1 factor by a newly established in vitro system. J Plant Physiol 2018; 222:79-85. [PMID: 29407552 DOI: 10.1016/j.jplph.2017.12.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [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: 06/16/2017] [Revised: 11/01/2017] [Accepted: 12/15/2017] [Indexed: 06/07/2023]
Abstract
The circadian clock is crucial for the synchronization of an organism's physiology and metabolism with the geophysical time. In plants, previous work on the common bean (Phaseolus vulgaris) has identified various differing aspects of clock function compared to the widely studied Arabidopsis thaliana clock. However, transformation of legumes for the study of the circadian clock regulatory mechanisms is extremely laborious. In the present work, we describe an easy-to-follow and rapid method of preparing bean leaf protoplasts with high transformation potential and a functional circadian clock. In this system, we show that application of trichostatin A differentially changes the expression levels of several clock genes. More importantly, we investigate the effect of the clock protein PvTOC1 (Phaseolus vulgaris TIMING OF CAB EXPRESSION 1) on the activity of bean circadian promoters. We present new evidence on the function of PvTOC1 as a repressor of the promoter activity of its own gene, mediated by its conserved CCT (CONSTANS, CO-LIKE and TOC1) domain. Using our protoplast system we were able to uncover functions of the bean circadian clock and to identify an additional target of the PvTOC1clock transcription factor, not previously reported.
Collapse
Affiliation(s)
- Angeliki Galeou
- National Centre for Scientific Research "DEMOKRITOS", Institute of Biosciences and Applications, Patr. Grigoriou E' & 27 Neapoleos str., 153 41, Agia Paraskevi, Greece; National and Kapodistrian University of Athens, Faculty of Biology, Department of Botany, 15784 Athens, Greece
| | - Andreas Roussis
- National and Kapodistrian University of Athens, Faculty of Biology, Department of Botany, 15784 Athens, Greece
| | - Anastasia Prombona
- National Centre for Scientific Research "DEMOKRITOS", Institute of Biosciences and Applications, Patr. Grigoriou E' & 27 Neapoleos str., 153 41, Agia Paraskevi, Greece.
| |
Collapse
|
5
|
Xydous M, Prombona A, Sourlingas TG. Corrigendum to "The role of H3K4me3 and H3K9/14ac in the induction by dexamethasone of Per1 and Sgk1, two glucocorticoid early response genes that mediate the effects of acute stress in mammals" [Biochim. Biophys. Acta 1839 (2014) 866-872]. Biochim Biophys Acta Gene Regul Mech 2017; 1860:392. [PMID: 28132760 DOI: 10.1016/j.bbagrm.2017.01.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- M Xydous
- Laboratory of Nuclear Proteins and Chromatin Function, Institute of Biosciences and Applications, National Center for Scientific Research "DEMOKRITOS", P.O.B. 60037, Aghia Paraskevi 153 10, Attiki, Greece
| | - A Prombona
- Laboratory of Chronobiology, Institute of Biosciences and Applications, National Center for Scientific Research "DEMOKRITOS", P.O.B. 60037, Aghia Paraskevi 153 10, Attiki, Greece
| | - T G Sourlingas
- Laboratory of Nuclear Proteins and Chromatin Function, Institute of Biosciences and Applications, National Center for Scientific Research "DEMOKRITOS", P.O.B. 60037, Aghia Paraskevi 153 10, Attiki, Greece.
| |
Collapse
|
6
|
Perdikaki A, Galeou A, Pilatos G, Karatasios I, Kanellopoulos NK, Prombona A, Karanikolos GN. Ag and Cu Monometallic and Ag/Cu Bimetallic Nanoparticle-Graphene Composites with Enhanced Antibacterial Performance. ACS Appl Mater Interfaces 2016; 8:27498-27510. [PMID: 27680975 DOI: 10.1021/acsami.6b08403] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Increased proliferation of antimicrobial resistance and new strains of bacterial pathogens severely impact current health, environmental, and technological developments, demanding design of novel, highly efficient antibacterial agents. Ag, Cu monometallic and Ag/Cu bimetallic nanoparticles (NPs) were in situ grown on the surface of graphene, which was produced by chemical vapor deposition using ferrocene as precursor and further functionalized to introduce oxygen-containing surface groups. The antibacterial performance of the resulting hybrids was evaluated against Escherichia coli cells and compared through a series of parametrization experiments of varying metal type and concentration. It was found that both Ag- and Cu-based monometallic graphene composites significantly suppress bacterial growth, yet the Ag-based ones exhibit higher activity compared to that of their Cu-based counterparts. Compared with well-dispersed colloidal Ag NPs of the same metal concentration, Ag- and Cu-based graphene hybrids display weaker antibacterial activity. However, the bimetallic Ag/CuNP-graphene hybrids exhibit superior performance compared to that of all other materials tested, i.e., both the monometallic graphene structures as well as the colloidal NPs, achieving complete bacterial growth inhibition at all metal concentrations tested. This striking performance is attributed to the synergistic action of the combination of the two different metals that coexist on the surface as well as the enhancing role of the graphene support.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Georgios N Karanikolos
- Department of Chemical Engineering, The Petroleum Institute , P.O. Box 2533, Abu Dhabi, United Arab Emirates
| |
Collapse
|
7
|
Repouskou A, Prombona A. c-MYC targets the central oscillator gene Per1 and is regulated by the circadian clock at the post-transcriptional level. Biochim Biophys Acta 2016; 1859:541-52. [PMID: 26850841 DOI: 10.1016/j.bbagrm.2016.02.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [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: 09/30/2015] [Revised: 01/14/2016] [Accepted: 02/01/2016] [Indexed: 12/27/2022]
Abstract
Cell proliferation in mammals follows a circadian rhythm while disruption of clock gene expression has been linked to tumorigenesis. Expression of the c-Myc oncogene is frequently deregulated in tumors, facilitating aberrant cell proliferation. c-MYC protein levels display circadian rhythmicity, which is compatible with an in vitro repressive role of the clock-activating complex BMAL1/CLOCK on its promoter. In this report, we provide evidence for the in vivo binding of the core circadian factor BMAL1 on the human c-Myc promoter. In addition, analysis of protein synthesis and degradation rates, as well as post-translational acetylation, demonstrate that the clock tightly controls cellular MYC levels. The oncoprotein itself is a transcription factor that by responding to mitogenic signals regulates the expression of several hundred genes. c-MYC-driven transcription is generally exerted upon dimerization with MAX and binding to E-box elements, a sequence that is also recognized by the circadian heterodimer. Our reporter assays reveal that the MYC/MAX dimer cannot affect transcription of the circadian gene Per1. However, when overexpressed, c-MYC is able to repress Per1 transactivation by BMAL1/CLOCK via targeting selective E-box sequences. Importantly, upon serum stimulation, MYC was detected in BMAL1 protein complexes. Together, these data demonstrate a novel interaction between MYC and circadian transactivators resulting in reduced clock-driven transcription. Perturbation of Per1 expression by MYC constitutes a plausible alternative explanation for the deregulated expression of clock genes observed in many types of cancer.
Collapse
Affiliation(s)
- Anastasia Repouskou
- Institute of Biosciences and Applications, Laboratory of Chronobiology, NCSR 'Demokritos', 15310 Aghia Paraskevi, Attiki, Greece.
| | - Anastasia Prombona
- Institute of Biosciences and Applications, Laboratory of Chronobiology, NCSR 'Demokritos', 15310 Aghia Paraskevi, Attiki, Greece.
| |
Collapse
|
8
|
Xydous M, Sekeri-Pataryas KE, Prombona A, Sourlingas TG. Nicotinamide treatment reduces the levels of histone H3K4 trimethylation in the promoter of the mper1 circadian clock gene and blocks the ability of dexamethasone to induce the acute response. Biochim Biophys Acta 2012; 1819:877-84. [PMID: 22465780 DOI: 10.1016/j.bbagrm.2012.03.001] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Revised: 03/09/2012] [Accepted: 03/14/2012] [Indexed: 10/28/2022]
Abstract
Circadian rhythms, which measure time on a scale of 24h, are generated by one of the most ubiquitous endogenous mechanisms, the circadian clock. SIRT1, a class III histone deacetylase, and PARP-1, a poly(ADP-ribose) polymerase, are two NAD(+)-dependent enzymes that have been shown to be involved in the regulation of the clock. Here we present evidence that the metabolite nicotinamide, an inhibitor of SIRT1, PARP-1 and mono(ADP-ribosyl) transferases, blocks the ability of dexamethasone to induce the acute response of the circadian clock gene, mper1, while it concomitantly reduces the levels of histone H3 trimethylation of lysine 4 (H3K4me3) in the mper1 promoter. Moreover, application of alternative inhibitors of SIRT1 and ADP-ribosylation did not lead to similar results. Therefore, inhibition of these enzymes does not seem to be the mode by which NAM exerts these effects. These results suggest the presence of a novel mechanism, not previously documented, by which NAM can alter gene expression levels via changes in the histone H3K4 trimethylation state.
Collapse
Affiliation(s)
- M Xydous
- Institute of Biology, National Center for Scientific Research, Attiki, Greece.
| | | | | | | |
Collapse
|
9
|
Galeou A, Prombona A. Light at night resynchronizes the evening-phased rhythms of TOC1 and ELF4 in Phaseolus vulgaris. Plant Sci 2012; 184:141-147. [PMID: 22284718 DOI: 10.1016/j.plantsci.2011.12.014] [Citation(s) in RCA: 2] [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] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Revised: 12/14/2011] [Accepted: 12/15/2011] [Indexed: 05/31/2023]
Abstract
Circadian clocks regulate the adaptation of the organisms' physiology to the environmental light-dark cycles. Photic resetting of the clock differs among plant species. In Arabidopsis thaliana, morning-phased genes are not responsive to light signals at night, while in Phaseolus vulgaris, morning-phased genes are responsive to light at trough phases that are reached during the night. In order to explore this further, in this work we investigated the light-responsiveness at night of two P. vulgaris evening phased genes, the orthologs of TOC1 and ELF4. Our results demonstrate that the oscillation of their expression is symphasic under all applied photic conditions. Thus, under photoperiod peak phases are obtained in the evening (LD 12:12) or early at night (LD 6:18). Light application at the beginning of the night under LD 6:18 results in a phase shift of the PvTOC1 and PvELF4 oscillation, while at the end of the night the phase remains unchanged. Moreover, when light is applied at the narrow time window of the peak phase, a significant transient increase in the expression of both PvTOC1 and PvELF4 is caused. These results indicate that, depending on the plant species, evening-phased genes may also participate in the resetting of the circadian clock machinery by light.
Collapse
Affiliation(s)
- Angeliki Galeou
- Institute of Biology, Chronobiology Laboratory, NCSR Demokritos, 15310 Aghia Paraskevi, Attiki, Greece
| | | |
Collapse
|
10
|
Repouskou A, Sourlingas TG, Sekeri-Pataryas KE, Prombona A. The circadian expression of c-MYC is modulated by the histone deacetylase inhibitor trichostatin A in synchronized murine neuroblastoma cells. Chronobiol Int 2010; 27:722-41. [PMID: 20560708 DOI: 10.3109/07420521003786800] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Circadian clocks govern the mammalian physiology in a day/night-dependent manner. The circadian oscillator of peripheral organs is composed of the same elements as the central pacemaker at the suprachiasmatic nucleus (SCN). The interaction between the circadian clock and several cell cycle components has been established in recent years, since many key regulators of cell cycle and growth control were proved to be rhythmically expressed. In particular, the proto-oncogene c-Myc has been documented to be under circadian regulation. Given that it is overexpressed in many malignancies, the study of c-Myc mRNA and c-MYC protein regulation by the circadian clock is of great interest. Thus, the aim of this work was to: (a) analyze in detail the circadian oscillations of c-Myc steady-state mRNA levels and to investigate whether c-MYC protein levels display any oscillating pattern, and (b) ascertain whether circadian time is important for reducing c-MYC levels after drug application. For this purpose, we selected trichostatin A (TSA), since it is known that long (>or=12 h) treatment durations negatively influence the expression levels of c-Myc and short 2 h treatments up regulate the expression of the central oscillator gene Per1 resulting in the resetting of its rhythm. TSA is a specific inhibitor of histone deacetylases (HDACs), and its application results in increased acetylation levels of histone and non-histone proteins. Our results, using the murine neuroblastoma cell line N2A, show that Per1 and c-Myc steady-state mRNA levels oscillate with the same phase. Moreover, a short 2 h TSA treatment causes a phase-dependent decrease of oscillating c-Myc transcript levels only when applied at the trough of its mRNA rhythm, where a general decrease of c-MYC protein levels is also observed. At the peak of its rhythm, no apparent changes can be observed. These experiments demonstrate for the first time that a significant decrease in c-Myc transcript and protein levels can be achieved after a short TSA treatment applied only at specific circadian times. This is also followed by a reduction in the proliferation rate of the cell population.
Collapse
Affiliation(s)
- Anastasia Repouskou
- Institute of Biology, Laboratory of Chronobiology, NCSR Demokritos, Ag. Paraskevi Attiki, Greece
| | | | | | | |
Collapse
|
11
|
Kaldis AD, Prombona A. Synergy between the light-induced acute response and the circadian cycle: a new mechanism for the synchronization of the Phaseolus vulgaris clock to light. Plant Mol Biol 2006; 61:883-95. [PMID: 16927202 DOI: 10.1007/s11103-006-0056-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2006] [Accepted: 03/27/2006] [Indexed: 05/11/2023]
Abstract
PvLHY and Lhcb expression has been studied in primary bean leaves after exposure of etiolated leaves to two or three white light-pulses and under different photoperiods. Under the tested photoperiods, the steady-state mRNA levels exhibit diurnal oscillations with zenith in the morning between ZT21 and 4 for PvLHY and between ZT4 and 6 for Lhcb. Nadir is in the evening between ZT12 and 18 for PvLHY and ZT18 and 24 for Lhcb. Light-pulses to etiolated seedlings induce a differentiated acute response that is reciprocally correlated with the amplitude of the following circadian cycle. In addition, the clock modulates the duration of the acute response (descending part of the curve included), which according to the phase of the rhythm at light application extends from 7 to 18 h. This constitutes the response dynamics of the Phaseolus clock to light. Similarly, the waveform of PvLHY and Lhcb expression during the day of different photoperiods resembles in induction capability (accomplishment of peak after lights-on) and duration (from lights-on phase to trough) the phase-dependent progression of acute response in etiolated seedlings. Consequently, the peak of Lhcb (all tested photoperiods) and PvLHY (in LD 18:6) attained in the photophase corresponds to the acute response peak, while the peak of PvLHY during the scotophase (in LD 12:12 and 6:18) corresponds to the circadian peak. Thus, the effect of the response dynamics in the photoperiod determines the coincidence of the peak with the photo- or scotophase, respectively. This represents a new model mechanism for the adaptation of the Phaseolus clock to light.
Collapse
|
12
|
Kaldis AD, Kousidis P, Kesanopoulos K, Prombona A. Light and circadian regulation in the expression of LHY and Lhcb genes in Phaseolus vulgaris. Plant Mol Biol 2003; 52:981-97. [PMID: 14558659 DOI: 10.1023/a:1025433529082] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
In order to understand some aspects of the circadian clock function in Phaseolus vulgaris, we analyzed the temporal transcript profile of Lhcb genes, typical clock reporters in plants, and that of PvLHY, an orthologue of Arabidopsis thaliana LHY which is a putative transcription factor of Lhcb genes. Under different light regimes, Lhcb and PvLHY exhibit a clear circadian pattern of expression. Moreover, the rhythm of Lhcb genes appears to be tightly coupled to that of PvLHY with the latter having a slightly earlier phase. This supports the idea that the oscillating capacity of PvLHY may be one of the causes of the rhythmic expression of Lhcb genes in bean. In addition to their circadian regulation, Lhcb and PvLHY are induced by light with similar and relatively slow induction kinetics. Moreover, this light induction is gated by the circadian oscillator: minimal responses occur at times around peaks of the pre-existing rhythm, while maximal ones occur at troughs of the pre-existing rhythm. This pattern of gating is opposite to that observed in Arabidopsis. The failure to block the light induction pathways at pre-existing troughs appears to have a detrimental effect to the subsequent circadian rhythmicity. Briefly, the overall regulation of PvLHY and Lhcb genes by light and the circadian clock reveals different strategies between Phaseolus and Arabidopsis in the adaptation to photoperiodic conditions.
Collapse
|
13
|
Tsapali DS, Sekeri-Pataryas KE, Prombona A, Sourlingas TG. mRNA levels of the linker histone variant, H1o, in mitotically active human diploid fibroblasts as a function of the phases of the cell cycle and cumulative population doublings. Mech Ageing Dev 2000; 121:101-12. [PMID: 11164464 DOI: 10.1016/s0047-6374(00)00201-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [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: 10/18/2022]
Abstract
Senescence and differentiation have many similarities with respect to certain aspects of gene expression and cell cycle related events. One linker histone variant tightly associated with differentiation is the H1 variant, H1o. The work of this investigation has focused on the expression of H1o during the phases of the cell cycle and as a function of increasing cumulative population doublings (CPD) in an in vitro model ageing cell system, namely, human diploid fibroblasts. Increased H1o mRNA levels were found during the S phase of the cell cycle contrary to H1o protein relative synthesis rates, which were found to be increased during the Go phase of the cell cycle. These results were obtained in actively proliferating cell populations. However when the proliferative rate of the overall population begins to drop (CPD 50), H1o mRNA levels tend to remain stable throughout the Go, G1 and S phases. On the other hand, no changes in the H1o relative synthesis rates were found as a function of increasing CPD. Uncoupling of H1o protein and mRNA levels has been observed in numerous differentiating systems. The analogous mode in which H1o gene expression is regulated in both these two systems reinforces the opinion that senescence and differentiation may have similarities at the level of chromatin remodelling.
Collapse
Affiliation(s)
- D S Tsapali
- National Center for Scientific Research Demokritos, Institute of Biology, Aghia Paraskevi, 15310 Athens, Greece
| | | | | | | |
Collapse
|
14
|
Argyroudi-Akoyunoglou JH, Prombona A. Light-independent endogenous circadian rhythm in the capacity for chlorophyll formation. Journal of Photochemistry and Photobiology B: Biology 1996. [DOI: 10.1016/s1011-1344(96)07380-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
15
|
Prombona A, Tabler M, Providaki M, Tsagris M. Structure and expression of LeMA-1, a tomato protein belonging to the SEC18-PAS1-CDC48-TBP-1 protein family of putative Mg(2+)-dependent ATPases. Plant Mol Biol 1995; 27:1109-1118. [PMID: 7766893 DOI: 10.1007/bf00020884] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
cDNA clones of a tomato protein, called Lycopersicum esculentum putative Mg(2+)-dependent ATPase (LeMA-1), were isolated from a cDNA library. Sequence comparison of the tomato protein with other genes in the database revealed that the protein is highly homologous to a human protein called TBP-1 and a yeast Tat-binding-analogue protein YTA1A. All three proteins belong to the recently discovered protein family of putative Mg(2+)-dependent ATPases and form within this family a subgroup of proteins involved in controlled protein degradation and possibly also in transcriptional regulation. Expression of the mRNA of LeMA-1 could be monitored in several plant tissues. LeMA-1 is the first member of this subgroup of proteins isolated from plants.
Collapse
Affiliation(s)
- A Prombona
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology, Hellas, Heraklion, Greece
| | | | | | | |
Collapse
|
16
|
Hess WR, Prombona A, Fieder B, Subramanian AR, Börner T. Chloroplast rps15 and the rpoB/C1/C2 gene cluster are strongly transcribed in ribosome-deficient plastids: evidence for a functioning non-chloroplast-encoded RNA polymerase. EMBO J 1993; 12:563-71. [PMID: 8440246 PMCID: PMC413239 DOI: 10.1002/j.1460-2075.1993.tb05688.x] [Citation(s) in RCA: 119] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Transcription of plastid genes and transcript accumulation were investigated in white leaves of the albostrians mutant of barley (Hordeum vulgare) and in heat-bleached leaves of rye (Secale cereale) as well as in normal green leaves of both species. Cells of white leaves of the mutant and cells of heat-bleached leaves bear undifferentiated plastids lacking ribosomes and, consequently, plastid translation products, among them the subunits of a putative chloroplast RNA polymerase encoded by the plastid genes rpoA, B, C1 and C2. The following results were obtained. (i) Plastid genes are transcribed despite the lack of chloroplast gene-encoded RNA polymerase subunits. The plastid origin of these transcripts was proven. This finding provides evidence for the existence of a plastid RNA polymerase encoded entirely by nuclear genes. (ii) Transcripts of the rpo genes and of rps15, but not of genes involved in photosynthesis and related processes (psbA, rbcL, atpI-H), were abundantly accumulated in ribosome-deficient plastids. In contrast, chloroplasts accumulated transcripts of photosynthetic, but not of the rpo genes. (iii) Differences in transcript accumulation between chloroplasts and ribosome-deficient plastids are due to different relative transcription rates and different transcript stability. (iv) The observed differences in transcription are not caused by an altered pattern of methylation of plastid DNA. Thus, the prokaryotic plastid genome of higher plants is transcribed by two RNA polymerases. The observed differences in transcription between chloroplasts and undifferentiated plastids might reflect different functions of the two enzymes.
Collapse
Affiliation(s)
- W R Hess
- Humboldt University Berlin, Department of Genetics, Germany
| | | | | | | | | |
Collapse
|
17
|
Prombona A, Subramanian AR. Construction of a chloroplast DNA library from rye (Secale cereale), a cereal plant of temperature-inducible chloroplast ribosome deficiency. Biochem Int 1991; 24:559-66. [PMID: 1772433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The chloroplast genomes of flowering plants are circular DNA molecules, 120 to 160 kilobase pairs long, encoding the rRNA, all tRNAs, and 21 r-proteins of the chloroplast translational apparatus as well as key protein components of the photosynthetic and carbon reduction cycle reactions. In this paper we describe some characteristics of the rye chloroplast (plastid) genome and the construction and characterization of a clone library of 93% of its DNA in a plasmid and a cosmid vector. The size of rye chloroplast DNA is estimated at 135 kbp, similar to that for wheat and rice but slightly smaller than the estimate for maize (139 kbp). Chloroplast ribosome deficiency is induced in rye seedlings by germination and growth at 32 degrees-34 degrees C; therefore these clones would be useful for analyzing the regulation of chloroplast ribosome synthesis in higher plants, a process that requires coordinate expression of genes located in the nucleus and the chloroplast.
Collapse
Affiliation(s)
- A Prombona
- Max-Planck-Institut für Molekulare Genetik, Abteilung Wittmann, Berlin
| | | |
Collapse
|
18
|
Prombona A, Subramanian AR. A new rearrangement of angiosperm chloroplast DNA in rye (Secale cereale) involving translocation and duplication of the ribosomal rpS15 gene. J Biol Chem 1989; 264:19060-5. [PMID: 2808411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The mapping and nucleotide sequencing of the rpS15 gene in the rye chloroplast DNA has shown that it is located in the inverted repeat (IR) and thus has two copies/genome. This is in contrast to tobacco and liverwort chloroplasts where rpS15 occurs as single-copy gene localized in the small single copy region (SSC). The direction of transcription of both gene copies in rye is toward SSC; that in tobacco and liverwort is toward IR-II. Further sequence data have revealed that the 3' end of each rye rpS15 gene copy is only 352 base pairs away from the corresponding IR.SSC junction and that this rearrangement event in rye involves also a 3' downstream-encoded and highly conserved chloroplast gene designated ORF393 in tobacco and ORF392 in liverwort. The latter in rye starts in both the IRs, but continues to full length into the SSC only from the IR-II. The direction of transcription of the nontruncated gene is fixed toward IR-I, being thus the inverse of ORF393/392 in tobacco and liverwort. Northern blot analysis has shown that the rearranged rpS15 gene is actively transcribed in rye chloroplasts and etioplasts and that its transcription pattern is different from that recently reported for tobacco rpS15.
Collapse
Affiliation(s)
- A Prombona
- Max-Planck Institute für Molekulare Genetik, Abteilung Wittmann, Berlin, West, Federal Republic of Germany
| | | |
Collapse
|
19
|
Prombona A, Subramanian AR. A new rearrangement of angiosperm chloroplast DNA in rye (Secale cereale) involving translocation and duplication of the ribosomal rpS15 gene. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(19)47266-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
|
20
|
|