- MeSH
- Whole-Body Irradiation MeSH
- Humans MeSH
- Papio * MeSH
- Radiobiology MeSH
- Gene Expression Regulation radiation effects MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Review MeSH
Biological effects of high fluence low-power (HFLP) lasers have been reported for some time, yet the molecular mechanisms procuring cellular responses remain obscure. A better understanding of the effects of HFLP lasers on living cells will be instrumental for the development of new experimental and therapeutic strategies. Therefore, we investigated sub-cellular mechanisms involved in the laser interaction with human hepatic cell lines. We show that mitochondria serve as sub-cellular "sensor" and "effector" of laser light non-specific interactions with cells. We demonstrated that despite blue and red laser irradiation results in similar apoptotic death, cellular signaling and kinetic of biochemical responses are distinct. Based on our data, we concluded that blue laser irradiation inhibited cytochrome c oxidase activity in electron transport chain of mitochondria. Contrary, red laser triggered cytochrome c oxidase excessive activation. Moreover, we showed that Bcl-2 protein inhibited laser-induced toxicity by stabilizing mitochondria membrane potential. Thus, cells that either overexpress or have elevated levels of Bcl-2 are protected from laser-induced cytotoxicity. Our findings reveal the mechanism how HFLP laser irradiation interfere with cell homeostasis and underscore that such laser irradiation permits remote control of mitochondrial function in the absence of chemical or biological agents.
- MeSH
- Apoptosis radiation effects MeSH
- Hep G2 Cells MeSH
- Phototherapy * MeSH
- Low-Level Light Therapy * MeSH
- Humans MeSH
- Membrane Potential, Mitochondrial genetics radiation effects MeSH
- Mitochondrial Membranes metabolism radiation effects MeSH
- Mitochondria genetics radiation effects MeSH
- Oxidation-Reduction radiation effects MeSH
- Reactive Oxygen Species metabolism MeSH
- Gene Expression Regulation radiation effects MeSH
- Electron Transport Complex IV genetics MeSH
- Electron Transport genetics radiation effects MeSH
- Cell Survival genetics radiation effects MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
Radiotherapy is an important therapeutic approach against cervical cancer but associated with adverse effects including vaginal fibrosis and dyspareunia. We here assessed the immunological and oxidative responses to cervical irradiation in an animal model for radiation-induced cervicitis. Rats were sedated and either exposed to 20 Gy of ionising radiation given by a linear accelerator or only sedated (controls) and euthanized 1-14 days later. The expressions of toll-like receptors (TLRs) and coupled intracellular pathways in the cervix were assessed with immunohistofluorescence and western blot. Expression of cytokines were analysed with the Bio-Plex Suspension Array System (Bio-Rad). We showed that TLRs 2-9 were expressed in the rat cervix and cervical irradiation induced up-regulation of TLR5, TRIF and NF-κB. In the irradiated cervical epithelium, TLR5 and TRIF were increased in concert with an up-regulation of oxidative stress (8-OHdG) and antioxidant enzymes (SOD-1 and catalase). G-CSF, M-CSF, IL-10, IL- 17A, IL-18 and RANTES expressions in the cervix decreased two weeks after cervical irradiation. In conclusion, the rat uterine cervix expresses the TLRs 2-9. Cervical irradiation induces immunological changes and oxidative stress, which could have importance in the development of adverse effects to radiotherapy.
- MeSH
- Adaptor Proteins, Vesicular Transport immunology MeSH
- Cervix Uteri immunology pathology MeSH
- Cytokines immunology MeSH
- Radiation Injuries, Experimental immunology pathology MeSH
- Rats MeSH
- NF-kappa B immunology MeSH
- Oxidative Stress immunology radiation effects MeSH
- Rats, Sprague-Dawley MeSH
- Gene Expression Regulation immunology radiation effects MeSH
- Toll-Like Receptors immunology MeSH
- Uterine Cervicitis immunology pathology MeSH
- Gamma Rays adverse effects MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Repair of ribosomal DNA (rDNA) is a very important nuclear process due to the most active transcription of ribosomal genes. Proper repair of rDNA is required for physiological biogenesis of ribosomes. Here, we analyzed the epigenetics of the DNA damage response in a nucleolar compartment, thus in the ribosomal genes studied in nonirradiated and UVA-irradiated mouse embryonic fibroblasts (MEFs). We found that the promoter of ribosomal genes is not abundant on H4K20me2, but it is densely occupied by H4K20me3. Ribosomal genes, regulated via UBF1/2 proteins, were characterized by an interaction between UBF1/2 and H4K20me2/me3. This interaction was strengthened by UVA irradiation that additionally causes a focal accumulation of H4K20me3 in the nucleolus. No interaction has been found between UBF1/2 and H3K9me3. Interestingly, UVA irradiation decreases the levels of H3K9me3 and H4K20me3 at 28S rDNA. Altogether, the UVA light affects the epigenetic status of ribosomal genes at 28S rDNA and strengthens an interaction between UBF1/2 proteins and H4K20me2/me3.
- MeSH
- Cell Nucleolus metabolism MeSH
- Cell Nucleus metabolism MeSH
- Chromatin Immunoprecipitation MeSH
- DNA-Binding Proteins MeSH
- Epigenesis, Genetic radiation effects MeSH
- Fluorescent Antibody Technique MeSH
- Histones metabolism MeSH
- Methylation MeSH
- Mice MeSH
- Promoter Regions, Genetic MeSH
- Gene Expression Regulation radiation effects MeSH
- DNA, Ribosomal genetics MeSH
- Pol1 Transcription Initiation Complex Proteins metabolism MeSH
- Ultraviolet Rays * MeSH
- Protein Binding MeSH
- High-Throughput Nucleotide Sequencing MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The physiological function of the pancreas is controlled by the circadian clock. The aim of this study was to determine whether aging-induced changes in glucose homeostasis affect properties of the circadian clock in the pancreas and/or its sensitivity to disturbances in environmental lighting conditions. mPer2Luc mice aged 24-26 months developed hyperinsulinemic hypoglycaemia, which was likely due to the Pclo-mediated insulin hyper-secretion and Slc2a2-mediated glucose transport impairment in the pancreas, and due to the alterations in Pp1r3c-related glycogen storage and Sgk1-related glucose transport in the liver. In the pancreatic tissue, aging affected clock gene expression only marginally, it upregulated Bmal1 and downregulated Clock expression. Whereas aging significantly impaired the circadian clock in lung explants, which were used as a control tissue, the properties of the pancreatic clock in vitro were not affected. The data suggest a non-circadian role of Bmal1 in changes of pancreatic function that occur during aging. Additionally, the pancreatic clock was more sensitive to exposure of animals to constant light conditions. These findings provide an explanation for the previously demonstrated relationship between disturbances in the circadian system and disordered glucose homeostasis, including diabetes mellitus type 2, in subjects exposed to long-term shift work.
- MeSH
- Circadian Clocks * radiation effects MeSH
- Period Circadian Proteins metabolism MeSH
- Glucose metabolism MeSH
- Homeostasis * MeSH
- Liver metabolism MeSH
- Colon metabolism MeSH
- Mice MeSH
- Organ Specificity genetics MeSH
- Pancreas metabolism radiation effects MeSH
- CLOCK Proteins genetics metabolism MeSH
- Gene Expression Regulation radiation effects MeSH
- Aging metabolism MeSH
- Light MeSH
- ARNTL Transcription Factors genetics metabolism MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Mice MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Aging involves tissue accumulation of senescent cells (SC) whose elimination through senolytic approaches may evoke organismal rejuvenation. SC also contribute to aging-associated pathologies including cancer, hence it is imperative to better identify and target SC. Here, we aimed to identify new cell-surface proteins differentially expressed on human SC. Besides previously reported proteins enriched on SC, we identified 78 proteins enriched and 73 proteins underrepresented in replicatively senescent BJ fibroblasts, including L1CAM, whose expression is normally restricted to the neural system and kidneys. L1CAM was: 1) induced in premature forms of cellular senescence triggered chemically and by gamma-radiation, but not in Ras-induced senescence; 2) induced upon inhibition of cyclin-dependent kinases by p16INK4a; 3) induced by TGFbeta and suppressed by RAS/MAPK(Erk) signaling (the latter explaining the lack of L1CAM induction in RAS-induced senescence); and 4) induced upon downregulation of growth-associated gene ANT2, growth in low-glucose medium or inhibition of the mevalonate pathway. These data indicate that L1CAM is controlled by a number of cell growth- and metabolism-related pathways during SC development. Functionally, SC with enhanced surface L1CAM showed increased adhesion to extracellular matrix and migrated faster. Our results provide mechanistic insights into senescence of human cells, with implications for future senolytic strategies.
- MeSH
- Cell Adhesion physiology MeSH
- Cell Cycle MeSH
- Down-Regulation MeSH
- Fibroblasts MeSH
- Real-Time Polymerase Chain Reaction MeSH
- Humans MeSH
- Neural Cell Adhesion Molecule L1 genetics metabolism MeSH
- Cell Line, Tumor MeSH
- Cell Movement physiology MeSH
- Reverse Transcriptase Polymerase Chain Reaction MeSH
- Gene Expression Regulation drug effects radiation effects MeSH
- RNA Interference MeSH
- Signal Transduction MeSH
- Cellular Senescence MeSH
- Transforming Growth Factor beta metabolism pharmacology MeSH
- Gamma Rays MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
BACKGROUND: Low iron bioavailability is a common feature of ocean surface water and therefore micro-algae developed original strategies to optimize iron uptake and metabolism. The marine picoeukaryotic green alga Ostreococcus tauri is a very good model for studying physiological and genetic aspects of the adaptation of the green algal lineage to the marine environment: it has a very compact genome, is easy to culture in laboratory conditions, and can be genetically manipulated by efficient homologous recombination. In this study, we aimed at characterizing the mechanisms of iron assimilation in O. tauri by combining genetics and physiological tools. Specifically, we wanted to identify and functionally characterize groups of genes displaying tightly orchestrated temporal expression patterns following the exposure of cells to iron deprivation and day/night cycles, and to highlight unique features of iron metabolism in O. tauri, as compared to the freshwater model alga Chalamydomonas reinhardtii. RESULTS: We used RNA sequencing to investigated the transcriptional responses to iron limitation in O. tauri and found that most of the genes involved in iron uptake and metabolism in O. tauri are regulated by day/night cycles, regardless of iron status. O. tauri lacks the classical components of a reductive iron uptake system, and has no obvious iron regulon. Iron uptake appears to be copper-independent, but is regulated by zinc. Conversely, iron deprivation resulted in the transcriptional activation of numerous genes encoding zinc-containing regulation factors. Iron uptake is likely mediated by a ZIP-family protein (Ot-Irt1) and by a new Fea1-related protein (Ot-Fea1) containing duplicated Fea1 domains. The adaptation of cells to iron limitation involved an iron-sparing response tightly coordinated with diurnal cycles to optimize cell functions and synchronize these functions with the day/night redistribution of iron orchestrated by ferritin, and a stress response based on the induction of thioredoxin-like proteins, of peroxiredoxin and of tesmin-like methallothionein rather than ascorbate. We briefly surveyed the metabolic remodeling resulting from iron deprivation. CONCLUSIONS: The mechanisms of iron uptake and utilization by O. tauri differ fundamentally from those described in C. reinhardtii. We propose this species as a new model for investigation of iron metabolism in marine microalgae.
- MeSH
- Adaptation, Biological MeSH
- Chlorophyta classification genetics metabolism MeSH
- Eukaryota genetics metabolism MeSH
- Photoperiod MeSH
- Phylogeny MeSH
- Phytoplankton genetics metabolism MeSH
- Stress, Physiological MeSH
- Homeostasis MeSH
- Copper metabolism MeSH
- Oxidation-Reduction MeSH
- Gene Expression Regulation radiation effects MeSH
- Plant Proteins genetics metabolism MeSH
- Cluster Analysis MeSH
- Signal Transduction MeSH
- Iron Compounds metabolism MeSH
- Gene Expression Profiling MeSH
- Transcriptome MeSH
- High-Throughput Nucleotide Sequencing MeSH
- Iron metabolism MeSH
- Publication type
- Journal Article MeSH
In large regions of the open ocean, iron is a limiting resource for phytoplankton. The reduction of iron quota and the recycling of internal iron pools are among the diverse strategies that phytoplankton have evolved to allow them to grow under chronically low ambient iron levels. Phytoplankton species also have evolved strategies to cope with sporadic iron supply such as long-term storage of iron in ferritin. In the picophytoplanktonic species Ostreococcus we report evidence from observations both in the field and in laboratory cultures that ferritin and the main iron-binding proteins involved in photosynthesis and nitrate assimilation pathways show opposite diurnal expression patterns, with ferritin being maximally expressed during the night. Biochemical and physiological experiments using a ferritin knock-out line subsequently revealed that this protein plays a central role in the diel regulation of iron uptake and recycling and that this regulation of iron homeostasis is essential for cell survival under iron limitation.
- MeSH
- Chemical Precipitation MeSH
- Circadian Rhythm * drug effects genetics radiation effects MeSH
- Ferritins genetics metabolism MeSH
- Phytoplankton drug effects genetics growth & development metabolism MeSH
- Mass Spectrometry MeSH
- Homeostasis * drug effects genetics radiation effects MeSH
- Kinetics MeSH
- Microbial Viability drug effects radiation effects MeSH
- Seawater microbiology MeSH
- Iron-Binding Proteins metabolism MeSH
- Gene Expression Regulation drug effects radiation effects MeSH
- Light MeSH
- Transcriptome genetics MeSH
- Blotting, Western MeSH
- Iron metabolism pharmacology MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Stress-induced fibroblast senescence is thought to contribute to skin aging. Ultraviolet light (UV) radiation is the most potent environmental risk factor in these processes. An Epilobium angustifolium (EA) extract was evaluated for its capacity to reverse the senescent response of normal human dermal fibroblasts (NHDF) in vitro and to exhibit skin photo-protection in vivo. The HPLC-UV-MS analysis of the EA preparation identified three major polyphenol groups: tannins (oenothein B), phenolic acids (gallic and chlorogenic acids) and flavonoids. EA extract increased the cell viability of senescent NHDF induced by serum deprivation. It diminished connective tissue growth factor and fibronectin gene expressions in senescent NHDF. Down-regulation of the UV-induced release of both matrix metalloproteinase-1 and -3 and the tissue inhibitor of matrix metalloproteinases-1 and -2, and also down-regulation of the gene expression of hyaluronidase 2 were observed in repeatedly UV-irradiated NHDF after EA extract treatment. Interestingly, EA extract diminished the down-regulation of sirtuin 1 dampened by UV-irradiation. The application of EA extract using a sub-irritating dose protected skin against UV-induced erythema formation in vivo. In summary, EA extract diminished stress-induced effects on NHDF, particularly on connective tissue growth factor, fibronectin and matrix metalloproteinases. These results collectively suggest that EA extract may possess anti-aging properties and that the EA polyphenols might account for these benefits.
- MeSH
- Child MeSH
- Adult MeSH
- Down-Regulation drug effects radiation effects MeSH
- Epilobium chemistry MeSH
- Erythema drug therapy etiology MeSH
- Extracellular Matrix drug effects metabolism radiation effects MeSH
- Phenotype MeSH
- Fibroblasts cytology drug effects metabolism radiation effects MeSH
- Fibronectins genetics MeSH
- GPI-Linked Proteins genetics MeSH
- Hyaluronoglucosaminidase genetics MeSH
- Skin cytology drug effects radiation effects MeSH
- Humans MeSH
- Adolescent MeSH
- Young Adult MeSH
- Cell Adhesion Molecules genetics MeSH
- Radiation-Protective Agents chemistry pharmacology therapeutic use MeSH
- Gene Expression Regulation drug effects radiation effects MeSH
- Plant Extracts chemistry pharmacology therapeutic use MeSH
- Connective Tissue Growth Factor genetics MeSH
- Sirtuin 1 genetics MeSH
- Cellular Senescence drug effects radiation effects MeSH
- Skin Aging drug effects radiation effects MeSH
- Ultraviolet Rays adverse effects MeSH
- Cell Survival drug effects radiation effects MeSH
- Check Tag
- Child MeSH
- Adult MeSH
- Humans MeSH
- Adolescent MeSH
- Young Adult MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
