BACKGROUND: The Werner syndrome protein (WRN) belongs to the RecQ family of helicases and its loss of function results in the premature aging disease Werner syndrome (WS). We previously demonstrated that an early cellular change induced by WRN depletion is a posttranscriptional decrease in the levels of enzymes involved in metabolic pathways that control macromolecular synthesis and protect from oxidative stress. This metabolic shift is tolerated by normal cells but causes mitochondria dysfunction and acute oxidative stress in rapidly growing cancer cells, thereby suppressing their proliferation. RESULTS: To identify the mechanism underlying this metabolic shift, we examined global protein synthesis and mRNA nucleocytoplasmic distribution after WRN knockdown. We determined that WRN depletion in HeLa cells attenuates global protein synthesis without affecting the level of key components of the mRNA export machinery. We further observed that WRN depletion affects the nuclear export of mRNAs and demonstrated that WRN interacts with mRNA and the Nuclear RNA Export Factor 1 (NXF1). CONCLUSIONS: Our findings suggest that WRN influences the export of mRNAs from the nucleus through its interaction with the NXF1 export receptor thereby affecting cellular proteostasis. In summary, we identified a new partner and a novel function of WRN, which is especially important for the proliferation of cancer cells.
- MeSH
- buněčné jádro metabolismus MeSH
- HeLa buňky MeSH
- helikasy RecQ genetika MeSH
- helikáza Wernerova syndromu metabolismus MeSH
- lidé MeSH
- messenger RNA genetika MeSH
- metabolické sítě a dráhy fyziologie MeSH
- nádorové buněčné linie MeSH
- nádory metabolismus MeSH
- oxidace-redukce MeSH
- posttranskripční úpravy RNA fyziologie MeSH
- proliferace buněk fyziologie MeSH
- proteiny vázající RNA metabolismus MeSH
- transport RNA fyziologie MeSH
- Wernerův syndrom metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Malfunction of the circadian timing system may result in cardiovascular and metabolic diseases, and conversely, these diseases can impair the circadian system. The aim of this study was to reveal whether the functional state of the circadian system of spontaneously hypertensive rats (SHR) differs from that of control Wistar rat. This study is the first to analyze the function of the circadian system of SHR in its complexity, i.e., of the central clock in the suprachiasmatic nuclei (SCN) as well as of the peripheral clocks. The functional properties of the SCN clock were estimated by behavioral output rhythm in locomotor activity and daily profiles of clock gene expression in the SCN determined by in situ hybridization. The function of the peripheral clocks was assessed by daily profiles of clock gene expression in the liver and colon by RT-PCR and in vitro using real time recording of Bmal1-dLuc reporter. The potential impact of the SHR phenotype on circadian control of the metabolic pathways was estimated by daily profiles of metabolism-relevant gene expression in the liver and colon. The results revealed that SHR exhibited an early chronotype, because the central SCN clock was phase advanced relative to light/dark cycle and the SCN driven output rhythm ran faster compared to Wistar rats. Moreover, the output rhythm was dampened. The SHR peripheral clock reacted to the dampened SCN output with tissue-specific consequences. In the colon of SHR the clock function was severely altered, whereas the differences are only marginal in the liver. These changes may likely result in a mutual desynchrony of circadian oscillators within the circadian system of SHR, thereby potentially contributing to metabolic pathology of the strain. The SHR may thus serve as a valuable model of human circadian disorders originating in poor synchrony of the circadian system with external light/dark regime.
- MeSH
- časové faktory MeSH
- cirkadiánní hodiny * MeSH
- druhová specificita MeSH
- fenotyp MeSH
- fibroblasty metabolismus MeSH
- játra metabolismus patofyziologie MeSH
- kolon metabolismus patofyziologie MeSH
- krysa rodu rattus MeSH
- metabolické sítě a dráhy fyziologie MeSH
- nucleus suprachiasmaticus metabolismus patofyziologie MeSH
- orgánová specificita MeSH
- pohybová aktivita fyziologie MeSH
- potkani inbrední SHR MeSH
- transkriptom MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Převažující aerobní glykolýza v nádorových buňkách (tzv. Warburgův efekt) je na základě současných poznatků důsledkem přeprogramování buněčného metabolizmu během procesu maligní transformace. Regulace metabolizmu je neoddělitelnou komponentou procesu buněčné proliferace a je těsně svázána s aktivitami onkogenů a supresorových genů. Smyslem metabolické transformace nádorových buněk (a rovněž normálních intenzivně proliferujících buněk) je inkorporovat větší podíl metabolitů glukózy do nově syntetizovaných makromolekul. Mimo to aerobní glykolýza poskytuje nádorovým buňkám několik dalších selektivních výhod. Epidemiologická data naznačují, že diabetes mellitus 2. typu je asociován s rostoucí incidencí několika typů nádorů a že mortalita v důsledku nádorových onemocnění může být ovlivněna léčbou určitými druhy antidiabetik, nicméně další výzkum je nutný k vysvětlení toho, zda je tento vztah kauzální. Hlubší pochopení metabolizmu rychle proliferujících buněk může vést k dalšímu zlepšení protinádorové, imunosupresivní a protizánětové léčby.
The prevailing aerobic glycolysis (so called Warburg effect) in cancer cells is according to current understanding the consequence of reprogramming of cellular metabolism during the process of malignant transformation. Metabolic regulation is inseparable component of cell proliferation machinery and has a tight link with activities of oncogenes and suppressor genes. The purpose of metabolic reprogramming of cancer (but also normal intensively proliferating cells) is to incorporate greater fraction of glucose metabolites into newly synthesised macromolecules. Apart from that, aerobic glycolysis confers several other selective advantages to cancer cells. Epidemiological data indicate that type 2 diabetes mellitus is associated with increased incidence of several types of cancer and that cancer mortality can be influenced by certain types of anti-diabetic treatment, however future research is needed to explain whether this relationship might be causal. Deeper knowledge about metabolic properties of rapidly proliferating cells can be exploited for further improvement of anti-cancer, immunosuppressive or anti-inflammatory therapies.
- Klíčová slova
- p53, lýtransketoláza, glyoxaláza, metabolizmus,
- MeSH
- aerobióza MeSH
- diabetes mellitus 2. typu * komplikace MeSH
- glukosa metabolismus MeSH
- glykolýza fyziologie MeSH
- hypoglykemika škodlivé účinky MeSH
- lidé MeSH
- metabolické sítě a dráhy fyziologie MeSH
- metformin farmakologie škodlivé účinky terapeutické užití MeSH
- nádorová transformace buněk * metabolismus MeSH
- nádorový supresorový protein p53 metabolismus MeSH
- nádory * metabolismus MeSH
- obezita MeSH
- proliferace buněk MeSH
- transketolasa MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
- přehledy MeSH
We posit the following hypothesis: Independently of whether malignant tumors are initiated by a fundamental reprogramming of gene expression or seeded by stem cells, "waves" of gene expression that promote metabolic changes occur during carcinogenesis, beginning with oncogene-mediated changes, followed by hypoxia-induced factor (HIF)-mediated gene expression, both resulting in the highly glycolytic "Warburg" phenotype and suppression of mitochondrial biogenesis. Because high proliferation rates in malignancies cause aglycemia and nutrient shortage, the third (second oncogene) "wave" of adaptation stimulates glutaminolysis, which in certain cases partially re-establishes oxidative phosphorylation; this involves the LKB1-AMPK-p53, PI3K-Akt-mTOR axes and MYC dysregulation. Oxidative glutaminolysis serves as an alternative pathway compensating for cellular ATP. Together with anoxic glutaminolysis it provides pyruvate, lactate, and the NADPH pool (alternatively to pentose phosphate pathway). Retrograde signaling from revitalized mitochondria might constitute the fourth "wave" of gene reprogramming. In turn, upon reversal of the two Krebs cycle enzymes, glutaminolysis may partially (transiently) function even during anoxia, thereby further promoting malignancy. The history of the carcinogenic process within each malignant tumor determines the final metabolic phenotype of the selected surviving cells, resulting in distinct cancer bioenergetic phenotypes ranging from the highly glycolytic "classic Warburg" to partial or enhanced oxidative phosphorylation. We discuss the bioenergetically relevant functions of oncogenes, the involvement of mitochondrial biogenesis/degradation in carcinogenesis, the yet unexplained Crabtree effect of instant glucose blockade of respiration, and metabolic signaling stemming from the accumulation of succinate, fumarate, pyruvate, lactate, and oxoglutarate by interfering with prolyl hydroxylase domain enzyme-mediated hydroxylation of HIFα prolines.
- MeSH
- 1-fosfatidylinositol-3-kinasa metabolismus MeSH
- biologická adaptace fyziologie MeSH
- energetický metabolismus fyziologie MeSH
- geny myc fyziologie MeSH
- glukosa metabolismus MeSH
- glutamin metabolismus MeSH
- hypoxie buňky MeSH
- kyselina mléčná metabolismus MeSH
- kyselina pyrohroznová metabolismus MeSH
- lidé MeSH
- metabolické sítě a dráhy fyziologie MeSH
- mitochondrie metabolismus MeSH
- nádory metabolismus MeSH
- oxidativní fosforylace MeSH
- proliferace buněk MeSH
- protein-serin-threoninkinasy metabolismus MeSH
- regulace genové exprese fyziologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
Our previous work demonstrated the marked decrease of mitochondrial complex I activity in the cerebral cortex of immature rats during the acute phase of seizures induced by bilateral intracerebroventricular infusion of dl-homocysteic acid (600 nmol/side) and at short time following these seizures. The present study demonstrates that the marked decrease ( approximately 60%) of mitochondrial complex I activity persists during the long periods of survival, up to 5 weeks, following these seizures, i.e. periods corresponding to the development of spontaneous seizures (epileptogenesis) in this model of seizures. The decrease was selective for complex I and it was not associated with changes in the size of the assembled complex I or with changes in mitochondrial content of complex I. Inhibition of complex I was accompanied by a parallel, up to 5 weeks lasting significant increase (15-30%) of three independent mitochondrial markers of oxidative damage, 3-nitrotyrosine, 4-hydroxynonenal and protein carbonyls. This suggests that oxidative modification may be most likely responsible for the sustained deficiency of complex I activity although potential role of other factors cannot be excluded. Pronounced inhibition of complex I was not accompanied by impaired ATP production, apparently due to excess capacity of complex I documented by energy thresholds. The decrease of complex I activity was substantially reduced by treatment with selected free radical scavengers. It could also be attenuated by pretreatment with (S)-3,4-DCPG (an agonist for subtype 8 of group III metabotropic glutamate receptors) which had also a partial antiepileptogenic effect. It can be assumed that the persisting inhibition of complex I may lead to the enhanced production of reactive oxygen and/or nitrogen species, contributing not only to neuronal injury demonstrated in this model of seizures but also to epileptogenesis.
- MeSH
- agonisté excitačních aminokyselin farmakologie MeSH
- aldehydy metabolismus MeSH
- časové faktory MeSH
- down regulace účinky léků fyziologie MeSH
- energetický metabolismus účinky léků fyziologie MeSH
- epilepsie metabolismus patofyziologie MeSH
- homocystein analogy a deriváty toxicita MeSH
- konvulzíva toxicita MeSH
- krysa rodu rattus MeSH
- metabolické sítě a dráhy fyziologie MeSH
- míra přežití MeSH
- mitochondriální nemoci chemicky indukované metabolismus patofyziologie MeSH
- mitochondrie účinky léků metabolismus MeSH
- modely nemocí na zvířatech MeSH
- mozková kůra metabolismus patologie patofyziologie MeSH
- novorozená zvířata MeSH
- oxidační stres účinky léků fyziologie MeSH
- potkani Wistar MeSH
- respirační komplex I účinky léků metabolismus MeSH
- scavengery volných radikálů farmakologie MeSH
- tyrosin analogy a deriváty metabolismus MeSH
- záchvaty chemicky indukované metabolismus patofyziologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- MeSH
- biologické modely MeSH
- diabetes mellitus 1. typu komplikace krev metabolismus MeSH
- diabetes mellitus 2. typu komplikace krev metabolismus MeSH
- kardiovaskulární nemoci etiologie krev metabolismus MeSH
- komplikace diabetu metabolismus prevence a kontrola MeSH
- krevní glukóza metabolismus MeSH
- lidé MeSH
- metabolické sítě a dráhy fyziologie MeSH
- oxidační stres fyziologie MeSH
- produkty pokročilé glykace fyziologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
- souhrny MeSH
- MeSH
- chromatografie kapalinová metody využití MeSH
- chromatografie plynová metody využití MeSH
- endokrinologie metody normy statistika a číselné údaje MeSH
- financování organizované MeSH
- metabolické sítě a dráhy fyziologie účinky léků MeSH
- metoda nejmenších čtverců MeSH
- regresní analýza MeSH
- software MeSH
- statistika jako téma metody MeSH
- těhotenství MeSH
- Check Tag
- těhotenství MeSH
Metabolomics is the systematic identification and quantitation of all metabolites in a given organism or biological sample. The enhanced resolution provided by nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS), along with powerful chemometric software, allows the simultaneous determination and comparison of thousands of chemical entities, which has lead to an expansion of small molecule biochemistry studies in bacteria, plants, and mammals. Continued development of these analytical platforms will accelerate the widespread use of metabolomics and allow further integration of small molecules into systems biology. Here, recent studies using metabolomics in xenobiotic metabolism and genetically modified mice are highlighted.
- MeSH
- genotyp MeSH
- hmotnostní spektrometrie MeSH
- lidé MeSH
- magnetická rezonanční spektroskopie metody MeSH
- metabolické sítě a dráhy fyziologie genetika MeSH
- metabolismus MeSH
- myši knockoutované MeSH
- myši MeSH
- PPAR alfa genetika metabolismus MeSH
- software MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
