The human body is constantly exposed to ionizing radiation of different qualities. Especially the exposure to high-LET (linear energy transfer) particles increases due to new tumor therapy methods using e.g. carbon ions. Furthermore, upon radiation accidents, a mixture of radiation of different quality is adding up to human radiation exposure. Finally, long-term space missions such as the mission to mars pose great challenges to the dose assessment an astronaut was exposed to. Currently, DSB counting using γH2AX foci is used as an exact dosimetric measure for individuals. Due to the size of the γH2AX IRIF of ~ 0.6 μm, it is only possible to count DSB when they are separated by this distance. For high-LET particle exposure, the distance of the DSB is too small to be separated and the dose will be underestimated. In this study, we developed a method where it is possible to count DSB which are separated by a distance of ~ 140 nm. We counted the number of ionizing radiation-induced pDNA-PKcs (DNA-PKcs phosphorylated at T2609) foci (size = 140 nm ± 20 nm) in human HeLa cells using STED super-resolution microscopy that has an intrinsic resolution of 100 nm. Irradiation was performed at the ion microprobe SNAKE using high-LET 20 MeV lithium (LET = 116 keV/μm) and 27 MeV carbon ions (LET = 500 keV/μm). pDNA-PKcs foci label all DSB as proven by counterstaining with 53BP1 after low-LET γ-irradiation where separation of individual DSB is in most cases larger than the 53BP1 gross size of about 0.6 μm. Lithium ions produce (1.5 ± 0.1) IRIF/μm track length, for carbon ions (2.2 ± 0.2) IRIF/μm are counted. These values are enhanced by a factor of 2-3 compared to conventional foci counting of high-LET tracks. Comparison of the measurements to PARTRAC simulation data proof the consistency of results. We used these data to develop a measure for dosimetry of high-LET or mixed particle radiation exposure directly in the biological sample. We show that proper dosimetry for radiation up to a LET of 240 keV/μm is possible.

• MeSH
• biologické markery MeSH
• dávka záření MeSH
• dvouřetězcové zlomy DNA účinky záření   MeSH
• fluorescenční mikroskopie metody   MeSH
• fosforylace účinky záření   MeSH
• HeLa buňky MeSH
• lidé MeSH
• lineární přenos energie MeSH
• lithium škodlivé účinky   MeSH
• oprava DNA účinky záření   MeSH
• proteinkinasy účinky záření   MeSH
• radiační expozice MeSH
• radiometrie metody   MeSH
• těžké ionty škodlivé účinky   MeSH
• uhlík škodlivé účinky   MeSH
• záření gama škodlivé účinky   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Costunolide, a natural sesquiterpene lactone, has multiple pharmacological activities such as neuroprotection or induction of apoptosis and eryptosis. However, the effects of costunolide on pro-survival factors and enzymes in human erythrocytes, e.g. glutathione and glucose-6-phosphate dehydrogenase (G6PDH) respectively, have not been studied yet. Our aim was to determine the mechanisms underlying costunolide-induced eryptosis and to reverse this process. Phosphatidylserine exposure was estimated from annexin-V-binding, cell volume from forward scatter in flow cytometry, and intracellular glutathione [GSH]i from high performance liquid chromatography. The oxidized status of intracellular glutathione and enzyme activities were measured by spectrophotometry. Treatment of erythrocytes with costunolide dose-dependently enhanced the percentage of annexin-V-binding cells, decreased the cell volume, depleted [GSH]i and completely inhibited G6PDH activity. The effects of costunolide on annexin-V-binding and cell volume were significantly reversed by pre-treatment of erythrocytes with the specific PKC-α inhibitor chelerythrine. The latter, however, had no effect on costunolide-induced GSH depletion. Costunolide induces eryptosis, depletes [GSH]i and inactivates G6PDH activity. Furthermore, our study reveals an inhibitory effect of chelerythrine on costunolide-induced eryptosis, indicating a relationship between costunolide and PKC-α. In addition, chelerythrine acts independently of the GSH depletion. Understanding the mechanisms of G6PDH inhibition accompanied by GSH depletion should be useful for development of anti-malarial therapeutic strategies or for synthetic lethality-based approaches to escalate oxidative stress in cancer cells for their sensitization to chemotherapy and radiotherapy.

• MeSH
• apoptóza účinky léků   MeSH
• benzofenantridiny farmakologie   MeSH
• eryptóza účinky léků   genetika   MeSH
• erytrocyty účinky léků   patologie   MeSH
• glukosa-6-fosfátdehydrogenasa antagonisté a inhibitory   genetika   MeSH
• glutathion genetika   MeSH
• inhibitory enzymů farmakologie   MeSH
• lidé MeSH
• oxidační stres účinky léků   MeSH
• proteinkinasa C-alfa antagonisté a inhibitory   genetika   MeSH
• reaktivní formy kyslíku MeSH
• seskviterpeny farmakologie   MeSH
• vápník metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Although physical exercise is known to reduce size of infarction, incidence of ventricular arrhythmias, and to improve heart function, molecular mechanisms of this protection are not fully elucidated. We explored the hypothesis that voluntary running, similar to adaptive interventions, such as ischemic or remote preconditioning, may activate components of pro-survival (RISK) pathway and potentially modify cell proliferation. Sprague-Dawley adult male rats freely exercised for 23 days in cages equipped with running wheels, while sedentary controls were housed in standard cages. After 23 days, left ventricular (LV) myocardial tissue samples were collected for the detection of expression and activation of RISK proteins (WB). The day before, a marker of cell proliferation 5-bromo-2'-deoxyuridine (BrdU) was given to all animals to detect its incorporation into DNA of the LV cells (ELISA). Running increased phosphorylation (activation) of Akt, as well as the levels of PKC? and phospho-ERK1/2, whereas BrdU incorporation into DNA was unchanged. In contrast, exercise promoted pro-apoptotic signaling - enhanced Bax/Bcl-2 ratio and activation of GSK-3ß kinase. Results suggest that in the rat myocardium adapted to physical load, natural cardioprotective processes associated with physiological hypertrophy are stimulated, while cell proliferation is not modified. Up-regulation of pro-apoptotic markers indicates potential induction of cell death mechanisms that might lead to maladaptation in the long-term.

• MeSH
• kondiční příprava zvířat fyziologie   MeSH
• krysa rodu rattus MeSH
• mediátory zánětu metabolismus   MeSH
• míra přežití trendy   MeSH
• myokard metabolismus   patologie   MeSH
• náhodné rozdělení MeSH
• potkani Sprague-Dawley MeSH
• proliferace buněk fyziologie   MeSH
• rizikové faktory MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The Wee1 inhibitor MK1775 (AZD1775) is currently being tested in clinical trials for cancer treatment. Here, we show that the p53 target and CDK inhibitor p21 protects against MK1775-induced DNA damage during S-phase. Cancer and normal cells deficient for p21 (HCT116 p21-/-, RPE p21-/-, and U2OS transfected with p21 siRNA) showed higher induction of the DNA damage marker γH2AX in S-phase in response to MK1775 compared to the respective parental cells. Furthermore, upon MK1775 treatment the levels of phospho-DNA PKcs S2056 and phospho-RPA S4/S8 were higher in the p21 deficient cells, consistent with increased DNA breakage. Cell cycle analysis revealed that these effects were due to an S-phase function of p21, but MK1775-induced S-phase CDK activity was not altered as measured by CDK-dependent phosphorylations. In the p21 deficient cancer cells MK1775-induced cell death was also increased. Moreover, p21 deficiency sensitized to combined treatment of MK1775 and the CHK1-inhibitor AZD6772, and to the combination of MK1775 with ionizing radiation. These results show that p21 protects cancer cells against Wee1 inhibition and suggest that S-phase functions of p21 contribute to mediate such protection. As p21 can be epigenetically downregulated in human cancer, we propose that p21 levels may be considered during future applications of Wee1 inhibitors.

• MeSH
• checkpoint kinasa 1 antagonisté a inhibitory   MeSH
• cyklin-dependentní kinasy antagonisté a inhibitory   metabolismus   MeSH
• fosforylace účinky léků   MeSH
• HCT116 buňky MeSH
• inhibitor p21 cyklin-dependentní kinasy genetika   metabolismus   MeSH
• kontrolní body fáze S buněčného cyklu účinky léků   MeSH
• lidé MeSH
• malá interferující RNA genetika   MeSH
• nádory farmakoterapie   metabolismus   MeSH
• poškození DNA účinky léků   genetika   MeSH
• proteiny buněčného cyklu antagonisté a inhibitory   MeSH
• protinádorové látky farmakologie   terapeutické užití   MeSH
• pyrazoly farmakologie   terapeutické užití   MeSH
• pyrimidinony farmakologie   terapeutické užití   MeSH
• transfekce MeSH
• tyrosinkinasy antagonisté a inhibitory   MeSH
• viabilita buněk účinky léků   genetika   účinky záření   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Interplay between apicobasal cell polarity modules and the cytoskeleton is critical for differentiation and integrity of epithelia. However, this coordination is poorly understood at the level of gene regulation by transcription factors. Here, we establish the Drosophila activating transcription factor 3 (atf3) as a cell polarity response gene acting downstream of the membrane-associated Scribble polarity complex. Loss of the tumor suppressors Scribble or Dlg1 induces atf3 expression via aPKC but independent of Jun-N-terminal kinase (JNK) signaling. Strikingly, removal of Atf3 from Dlg1 deficient cells restores polarized cytoarchitecture, levels and distribution of endosomal trafficking machinery, and differentiation. Conversely, excess Atf3 alters microtubule network, vesicular trafficking and the partition of polarity proteins along the apicobasal axis. Genomic and genetic approaches implicate Atf3 as a regulator of cytoskeleton organization and function, and identify Lamin C as one of its bona fide target genes. By affecting structural features and cell morphology, Atf3 functions in a manner distinct from other transcription factors operating downstream of disrupted cell polarity.

• MeSH
• buněčná diferenciace MeSH
• chromatinová imunoprecipitace MeSH
• Drosophila melanogaster cytologie   genetika   MeSH
• endozomy metabolismus   MeSH
• geneticky modifikovaná zvířata MeSH
• imaginální disky cytologie   fyziologie   MeSH
• lamin typ A genetika   metabolismus   MeSH
• larva MeSH
• MAP kinasový signální systém MeSH
• nádorové supresorové proteiny genetika   metabolismus   MeSH
• nukleotidové motivy fyziologie   MeSH
• oči růst a vývoj   MeSH
• polarita buněk fyziologie   MeSH
• proteinkinasa C metabolismus   MeSH
• proteiny Drosophily genetika   metabolismus   MeSH
• transkripční faktor ATF3 genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Diabetická retinopatie je závažnou pozdní mikrovaskulární komplikací základního onemocnění diabetes mellitus. Přes významné pokroky posledních let v poznání molekulárních mechanismů, které stojí v pozadí diabetické retinopatie, nejsou některé aspekty její patofyziologie úplně odhaleny. Nejvýznamnější roli v patogenezi diabetické retinopatie hraje hyperglykémie. Dále jsou diskutovány role pokročilých produktů glykace, proteinkinázy C, oxidativního stresu, zánětu, vaskulárního endotelového růstového faktoru a sklivce. Přesné pochopení detailních mechanismů v diabetické retinopatii je nezbytné k vývoji nových léčiv a operačních postupů, které by mohly snížit nepříznivé dopady na vidění pacientů postižených diabetickou retinopatií.

Diabetic retinopathy is a serious late onset microvascular complication of diabetes mellitus. Even in spite of significant advances in understanding the molecular mechanisms behind DR, some of the aspects of its pathophysiology remain undiscovered. The key role in pathogenesis of diabetic retinopathy is played by hyperglycaemia. The possible roles of advanced products of glycation, proteinkinase C, oxidative stress, inflammation, vascular endothelial growth factor or vitreous humour are discussed as well. Precise understanding of the details of the mechanisms of diabetic retinopathy is necessary for developing new drugs and surgical procedures, which could lower the adverse effects on the sight of patients affected by diabetic retinopathy.

• MeSH
• diabetická retinopatie * etiologie   parazitologie   MeSH
• hyperglykemie komplikace   patofyziologie   MeSH
• lidé MeSH
• makulární edém * etiologie   patofyziologie   MeSH
• oxidační stres MeSH
• produkty pokročilé glykace škodlivé účinky   MeSH
• proteinkinasa C škodlivé účinky   MeSH
• rizikové faktory MeSH
• sklivec patofyziologie   patologie   MeSH
• vaskulární endoteliální růstové faktory antagonisté a inhibitory   MeSH
• Check Tag
• lidé MeSH

AIMS: Polymorphous low-grade adenocarcinoma (PLGA) is the second most common intra-oral salivary gland malignancy. The vast majority of PLGAs harbour a PRKD1 E710D hot-spot somatic mutation or somatic rearrangements of PRKD1, PRKD2 or PRKD3. Given the kinase domain homology among PRKD1, PRKD2 and PRKD3, we sought to define whether PLGAs lacking PRKD1 somatic mutations or PRKD gene family rearrangements would be driven by somatic mutations affecting the kinase domains of PRKD2 or PRKD3. METHODS AND RESULTS: DNA was extracted from eight microdissected PLGAs lacking PRKD1 somatic mutations or PRKD gene family rearrangements. Samples were thoroughly centrally reviewed, microdissected and subjected to Sanger sequencing of the kinase domains of the PRKD2 and PRKD3 genes. None of the PLGAs lacking PRKD1 somatic mutations or PRKD gene family rearrangements harboured somatic mutations in the kinase domains of the PRKD2 or PRKD3 genes. CONCLUSION: PLGAs lacking PRKD1 somatic mutations or PRKD gene family rearrangements are unlikely to harbour somatic mutations in the kinase domains of PRKD2 or PRKD3. Further studies are warranted to define the driver genetic events in this subgroup of PLGAs.

• MeSH
• adenokarcinom diagnóza   enzymologie   genetika   patologie   MeSH
• dospělí MeSH
• genotyp MeSH
• genová přestavba MeSH
• lidé středního věku MeSH
• lidé MeSH
• mikrodisekce MeSH
• mutace MeSH
• nádory slinných žláz diagnóza   enzymologie   genetika   patologie   MeSH
• proteinkinasa C genetika   MeSH
• proteinové domény MeSH
• sekvence aminokyselin MeSH
• sekvenční analýza DNA MeSH
• sekvenční seřazení MeSH
• senioři MeSH
• slinné žlázy patologie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Ischemic postconditioning and remote conditioning are potentially useful tools for protecting ischemic myocardium. This study tested the hypothesis that 2,3-dehydrosilybin (DHS), a flavonolignan component of Silybum marianum, could attenuate cardiomyocyte damage following hypoxia/reoxygenation by decreasing the generation of reactive oxygen species (ROS). After 5-6 days of cell culture in normoxic conditions the rat neonatal cardiomyocytes were divided into four groups. Control group (9 h at normoxic conditions), hypoxia/reoxygenation group (3 h at 1 % O₂, 94 % N₂and 5 % CO₂followed by 10 min of 10 micromol·l⁻¹DHS and 6 h of reoxygenation in normoxia) and postconditioning group (3 h of hypoxia, three cycles of 5 min reoxygenation and 5 min hypoxia followed by 6 h of normoxia). Cell viability assessed by propidium iodide staining was decreased after DHS treatment consistent with increased levels of lactatedehydrogenase (LDH) after reoxygenation. LDH leakage was significantly reduced when cardiomyocytes in the H/Re group were exposed to DHS. DHS treatment reduced H₂O₂production and also decreased the generation of ROS in the H/Re group as evidenced by a fluorescence indicator. DHS treatment reduces reoxygenation-induced injury in cardiomyocytes by attenuation of ROS generation, H₂O₂and protein carbonyls levels. In addition, we found that both the postconditioning protocol and the DHS treatment are associated with restored ratio of phosphorylated/total protein kinase C epsilon, relative to the H/Re group. In conclusion, our data support the protective role of DHS in hypoxia/reperfusion injury and indicate that DHS may act as a postconditioning mimic.

• MeSH
• antioxidancia farmakologie   MeSH
• cytoprotekce MeSH
• fosforylace MeSH
• ischemické přivykání MeSH
• karbonylace proteinů účinky léků   MeSH
• kardiomyocyty účinky léků   metabolismus   patologie   MeSH
• kultivované buňky MeSH
• L-laktátdehydrogenasa metabolismus   MeSH
• novorozená zvířata MeSH
• oxidační stres účinky léků   MeSH
• peroxid vodíku metabolismus   MeSH
• potkani Wistar MeSH
• proteinkinasa C-epsilon metabolismus   MeSH
• reperfuzní poškození myokardu metabolismus   patologie   prevence a kontrola   MeSH
• signální transdukce účinky léků   MeSH
• silymarin farmakologie   MeSH
• viabilita buněk účinky léků   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Polymorphous low-grade adenocarcinoma (PLGA) is the second most frequent type of malignant tumor of the minor salivary glands. We identified PRKD1 hotspot mutations encoding p.Glu710Asp in 72.9% of PLGAs but not in other salivary gland tumors. Functional studies demonstrated that this kinase-activating alteration likely constitutes a driver of PLGA.

• MeSH
• adenokarcinom genetika   patologie   MeSH
• buňky NIH 3T3 MeSH
• imunohistochemie MeSH
• imunoprecipitace MeSH
• konfokální mikroskopie MeSH
• lidé MeSH
• missense mutace genetika   MeSH
• molekulární modely * MeSH
• molekulární sekvence - údaje MeSH
• mutageneze MeSH
• myši MeSH
• nádory slinných žláz genetika   patologie   MeSH
• proteinkinasa C chemie   genetika   MeSH
• sekvence aminokyselin MeSH
• sekvenční analýza DNA MeSH
• sekvenční seřazení MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The involvement of members of the adipokinetic hormone (AKH) family in regulation of response to oxidative stress (OS) has been reported recently. However, despite these neuropeptides being the best studied family of insect hormones, their precise signaling pathways in their OS responsive role remain to be elucidated. In this study, we have used an in vitro assay to determine the importance of extra and intra-cellular Ca(2+) stores as well as the involvement of protein kinase C (PKC) and cyclic adenosine 3',5'-monophosphate (cAMP) pathways by which AKH exerts its anti-oxidative effects. Lipid peroxidation product (4-HNE) was significantly enhanced and membrane fluidity reduced in microsomal fractions of isolated brains (CNS) of Pyrrhocoris apterus when treated with hydrogen peroxide (H2O2), whereas these biomarkers of OS were reduced to control levels when H2O2 was co-treated with Pyrap-AKH. The effects of mitigation of OS in isolated CNS by AKH were negated when these treatments were conducted in the presence of Ca(2+) channel inhibitors (CdCl2 and thapsigargin). Presence of either bisindolylmaliemide or chelyrythrine chloride (inhibitors of PKC) in the incubating medium also compromised the anti-oxidative function of AKH. However, supplementing the medium with either phorbol myristate acetate (PMA, an activator of PKC) or forskolin (an activator of cAMP) restored the protective effects of exogenous AKH treatment by reducing 4-HNE levels and increasing membrane fluidity to control levels. Taken together, our results strongly implicate the importance of both PKC and cAMP pathways in AKHs' anti-oxidative action by mobilizing both extra and intra-cellular stores of Ca(2+).

• MeSH
• aldehydy metabolismus   MeSH
• AMP cyklický metabolismus   MeSH
• blokátory kalciových kanálů farmakologie   MeSH
• fluidita membrány účinky léků   MeSH
• Heteroptera MeSH
• hmyzí hormony fyziologie   MeSH
• kyselina pyrrolidonkarboxylová analogy a deriváty   MeSH
• oligopeptidy fyziologie   MeSH
• oxidační stres účinky léků   MeSH
• peroxidace lipidů účinky léků   MeSH
• proteinkinasa C metabolismus   MeSH
• signální transdukce účinky léků   fyziologie   MeSH
• tetradekanoylforbolacetát farmakologie   MeSH
• vápník metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH