Plants respond to diverse biotic and abiotic stimuli as well as to endogenous developmental cues. Many of these stimuli result in altered activity of phospholipase D (PLD), an enzyme that hydrolyzes structural phospholipids producing phosphatidic acid (PA). PA is a key signaling intermediate in animals, but its targets in plants are relatively uncharacterized. Recent studies have demonstrated that the cytoskeleton is a major target of PLD-PA signaling and identified a positive feedback loop between actin turnover and PLD activity. Moreover, two cytoskeletal proteins, capping protein and MAP65-1, have been identified as PA-binding proteins regulating actin and microtubule organization and dynamics. In this review, we highlight the role of the PLD-PA module as an important hub for housekeeping and stress-induced regulation of membrane-associated cytoskeletal dynamics.

• MeSH
• aktiny metabolismus   MeSH
• buněčná membrána metabolismus   MeSH
• cytoskelet metabolismus   MeSH
• fosfolipasa D metabolismus   MeSH
• fyziologický stres MeSH
• fyziologie rostlin MeSH
• kyseliny fosfatidové metabolismus   MeSH
• mikrotubuly metabolismus   MeSH
• rostlinné proteiny metabolismus   MeSH
• rostliny enzymologie   MeSH
• signální transdukce MeSH
• vazba proteinů MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH

Úvod. Značná časť neurónov počas ischemickej cievnej mozgovej príhody podlieha apoptóze. Sú údaje o zvýšených koncentráciách tumor nekrotizujúceho faktora-α (TNF-α) a iných cytokínov v periférnej krvi počas ischemickej cievnej mozgovej príhody (CMP). TNF-α je induktorom apoptózy a existujú tiež údaje o účasti sekrečnej fosfolipázy A2 (SFLA2) pri apoptóze. V predkladanej práci sme sa zamerali na štúdium vzťahu medzi apoptózou periférnych lymfocytov a aktivitou SFLA2 u pacientov s ischemickou cievnou mozgovou. Materiál a metodika. V súbore 21 pacientov s dokázanou ischemickou cievnou mozgovou príhodou sme porovnali aktivitu sekrečnej fosfolipázy A2 s hodnotami apoptózy periférnych lymfocytov na začiatku ochorenia (pred liečbou) a po liečbe. Výsledky. V súbore zdravých pacientov bola aktivita SFLA2 3,2 ± 0,9 nmol/mg proteínov/min. U pacientov s ischemickou CMP pred liečbou boli koncentrácie SFLA2 7,2 ± 1,1 nmol/mg proteínov/min. Po liečbe boli priemerné koncentrácie SFLA2 6,1 ± 0,8 nmol/mg proteínov/min. U zdravých boh hodnoty apoptózy lymfocytov v periférnej krvi 12,1 % ± 3,1. Pri ischemickej CMP pred liečbou boU priemerné hodnoty apoptózy periférnych lymfocytov 21,49 % ± 7,73, kým po ukončení Hečby dosahovah hodnoty 21,01 % ± 7,29. Záver. Zistili sme signifikantně vyššie hodnoty sérovej aktivity SFLA2 ako aj apoptózy periférnych lymfocytov v porovnaní so zdravými jedincami. Liečba významne neovplyvnila uveděné hodnoty.

Introduction. A significant proportion of neurons in the course of ischemic stroke undergoes apoptosis. There are data regarding elevated concentrations of tumor necrosis factor-α (TNF-α) and of other cytokines in the peripheral blood during ischemic stroke. TNF-α is an inductor of apoptosis and there are also data on the participation of secretory phospholipase A2 (SFLA2) in apoptosis. In the presented work, we have focused on studying the relationship between apoptosis of peripheral lymphocytes and SFLA2 activity in patients with ischemic stroke. Material and Methods. In a group of 21 patients with documented ischemic stroke, we compared the activity of secretory phospholipase A2 with values of apoptosis of peripheral lymphocytes at disease onset (before treatment) and after treatment. Results. In a group of healthy controls, the mean activity of SFLA2 was 3.2 ± 0.9 nmol/mg of proteins/min. In patients with ischemic stroke before treatment, the SFLA2 concentration was 7.2 ± 1.1 nmol/mg of proteins/min. After treatment, the mean SFLA2 concentration was 6.1 ± 0.8 nmol/mg of proteins/min. In normals, the values of apoptosis of lymphocytes in the peripheral blood were 12.1 ± 3.1 %. In ischemic stroke prior to treatment, the average value of apoptosis of peripheral lymphocytes were 21.49 ± 7.73 %, whereas after therapy they reached 21.01 ± 7.29 %. Conclusion. We found significantly higher levels of serum SFLA2 activity as well as higher apoptosis of peripheral lymphocytes in ischemic stroke patients when compared to healthy individuals. These values were not significantly influenced by treatment.

• MeSH
• apoptóza genetika   MeSH
• fosfolipasy A fyziologie   krev   MeSH
• interferon alfa fyziologie   krev   MeSH
• ischemie mozku diagnóza   farmakoterapie   patologie   MeSH
• klinické laboratorní techniky MeSH
• lidé středního věku MeSH
• lidé MeSH
• lymfocyty metabolismus   MeSH
• senioři MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• přehledy MeSH
• srovnávací studie MeSH

Perforated patch clamp recording was used to study the control of membrane potential (V(m)) and spontaneous electrical activity in the rat pinealocyte by norepinephrine. Norepinephrine did not alter spiking frequency. However, it was found to act through α(1B)-adrenoreceptors in a concentration-dependent manner (0.1-10 μM) to produce a biphasic change in V(m). The initial response was a hyperpolarization (∼13 mV from a resting potential of -46 mV) due to a transient (∼5 sec) outward K(+) current (∼50 pA). This current appears to be triggered by Ca(2+) released from intracellular stores, based on the observation that it was also seen in cells bathed in Ca(2+)-deficient medium. In addition, pharmacological studies indicate that this current was dependent on phospholipase C (PLC) activation and was in part mediated by bicuculline methiodide and apamin-sensitive Ca(2+)-controlled K(+) channels. The initial transient hyperpolarization was followed by a sustained depolarization (∼4 mV) due to an inward current (∼10 pA). This response was dependent on PLC-dependent activation of Na(+)/Ca(2+) influx but did not involve nifedipine-sensitive voltage-gated Ca(2+) channels. Together, these results indicate for the first time that activation of α(1B)-adrenoreceptors initiates a PLC-dependent biphasic change in pinealocyte V(m) characterized by an initial transient hyperpolarization mediated by a mixture of Ca(2+)-activated K(+) channels followed by a sustained depolarization mediated by a Ca(2+)-conducting nonselective cation channel. These observations indicate that both continuous elevation of intracellular Ca(2+) and sustained depolarization at approximately -40 mV are associated with and are likely to be required for activation of the pinealocyte.

• MeSH
• alfa-1-adrenergní receptory fyziologie   MeSH
• epifýza mozková cytologie   účinky léků   fyziologie   MeSH
• fosfolipasy typu C fyziologie   MeSH
• krysa rodu rattus MeSH
• membránové potenciály účinky léků   MeSH
• noradrenalin farmakologie   MeSH
• potkani Sprague-Dawley MeSH
• vápník metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Intramural MeSH

Plant phospholipase Ds (PLDs), essential regulators of phospholipid signaling, function in multiple signal transduction cascades; however, the mechanisms regulating PLDs in response to pathogens remain unclear. Here, we found that Arabidopsis (Arabidopsis thaliana) PLDδ accumulated in cells at the entry sites of the barley powdery mildew fungus, Blumeria graminis f. sp hordei Using fluorescence recovery after photobleaching and single-molecule analysis, we observed higher PLDδ density in the plasma membrane after chitin treatment; PLDδ also underwent rapid exocytosis. Fluorescence resonance energy transfer with fluorescence lifetime imaging microscopy showed that the interaction between PLDδ and the microdomain marker AtREMORIN1.3 (AtREM1.3) increased in response to chitin, indicating that exocytosis facilitates rapid, efficient sorting of PLDδ into microdomains upon pathogen stimulus. We further unveiled a trade-off between brefeldin A (BFA)-resistant and -sensitive pathways in secretion of PLDδ under diverse conditions. Upon pathogen attack, PLDδ secretion involved syntaxin-associated VAMP721/722-mediated exocytosis sensitive to BFA. Analysis of phosphatidic acid (PA), hydrogen peroxide, and jasmonic acid (JA) levels and expression of related genes indicated that the relocalization of PLDδ is crucial for its activation to produce PA and initiate reactive oxygen species and JA signaling pathways. Together, our findings revealed that the translocation of PLDδ to papillae is modulated by exocytosis, thus triggering PA-mediated signaling in plant innate immunity.plantcell;31/12/3015/FX1F1fx1.

• MeSH
• Arabidopsis genetika   imunologie   metabolismus   mikrobiologie   MeSH
• Ascomycota patogenita   MeSH
• brefeldin A imunologie   metabolismus   MeSH
• buněčná membrána metabolismus   MeSH
• chitin imunologie   metabolismus   MeSH
• cyklopentany metabolismus   MeSH
• exocytóza účinky léků   imunologie   MeSH
• fosfolipasa D genetika   metabolismus   MeSH
• kyseliny fosfatidové metabolismus   MeSH
• nemoci rostlin imunologie   mikrobiologie   MeSH
• oxylipiny metabolismus   MeSH
• peroxid vodíku metabolismus   MeSH
• přirozená imunita * účinky léků   MeSH
• proteiny huseníčku metabolismus   MeSH
• proteiny Qa-SNARE metabolismus   MeSH
• proteiny R-SNARE metabolismus   MeSH
• proteiny SNARE genetika   metabolismus   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• signální transdukce imunologie   fyziologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Exosomes are small vesicles that are secreted by cells and act as mediators of cell to cell communication. Because of their potential therapeutic significance, important efforts are being made towards characterizing exosomal contents. However, little is known about the mechanisms that govern exosome biogenesis. We have recently shown that the exosomal protein syntenin supports exosome production. Here we identify the small GTPase ADP ribosylation factor 6 (ARF6) and its effector phospholipase D2 (PLD2) as regulators of syntenin exosomes. ARF6 and PLD2 affect exosomes by controlling the budding of intraluminal vesicles (ILVs) into multivesicular bodies (MVBs). ARF6 also controls epidermal growth factor receptor degradation, suggesting a role in degradative MVBs. Yet ARF6 does not affect HIV-1 budding, excluding general effects on Endosomal Sorting Complexes Required for Transport. Our study highlights a novel pathway controlling ILV budding and exosome biogenesis and identifies an unexpected role for ARF6 in late endosomal trafficking.

• MeSH
• ADP-ribosylační faktory genetika   metabolismus   MeSH
• buněčné linie MeSH
• endozomální třídící komplexy pro transport genetika   metabolismus   MeSH
• erbB receptory metabolismus   MeSH
• exozómy enzymologie   genetika   metabolismus   MeSH
• fosfolipasa D genetika   metabolismus   MeSH
• HIV infekce genetika   metabolismus   virologie   MeSH
• HIV-1 fyziologie   MeSH
• lidé MeSH
• multivezikulární tělíska enzymologie   genetika   metabolismus   MeSH
• proteiny buněčného cyklu genetika   metabolismus   MeSH
• proteiny vázající vápník genetika   metabolismus   MeSH
• synteniny genetika   metabolismus   MeSH
• transport proteinů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Quorum sensing (QS) regulates group behaviors of Candida albicans such as biofilm, hyphal growth, and virulence factors. The sesquiterpene alcohol farnesol, a QS molecule produced by C. albicans, is known to regulate the expression of virulence weapons of this fungus. Fluconazole (FCZ) is a broad-spectrum antifungal drug that is used for the treatment of C. albicans infections. While FCZ can be cytotoxic at high concentrations, our results show that at much lower concentrations, quercetin (QC), a dietary flavonoid isolated from an edible lichen (Usnea longissima), can be implemented as a sensitizing agent for FCZ-resistant C. albicans NBC099, enhancing the efficacy of FCZ. QC enhanced FCZ-mediated cell killing of NBC099 and also induced cell death. These experiments indicated that the combined application of both drugs was FCZ dose dependent rather than QC dose dependent. In addition, we found that QC strongly suppressed the production of virulence weapons-biofilm formation, hyphal development, phospholipase, proteinase, esterase, and hemolytic activity. Treatment with QC also increased FCZ-mediated cell death in NBC099 biofilms. Interestingly, we also found that QC enhances the anticandidal activity of FCZ by inducing apoptotic cell death. We have also established that this sensitization is reliant on the farnesol response generated by QC. Molecular docking studies also support this conclusion and suggest that QC can form hydrogen bonds with Gln969, Thr1105, Ser1108, Arg1109, Asn1110, and Gly1061 in the ATP binding pocket of adenylate cyclase. Thus, this QS-mediated combined sensitizer (QC)-anticandidal agent (FCZ) strategy may be a novel way to enhance the efficacy of FCZ-based therapy of C. albicans infections.

• MeSH
• antifungální látky farmakologie   MeSH
• antioxidancia farmakologie   MeSH
• apoptóza účinky léků   MeSH
• biofilmy účinky léků   MeSH
• Candida albicans účinky léků   MeSH
• faktory virulence metabolismus   MeSH
• flukonazol farmakologie   MeSH
• fungální léková rezistence účinky léků   MeSH
• hyfy účinky léků   MeSH
• mikrobiální testy citlivosti MeSH
• quercetin farmakologie   MeSH
• quorum sensing účinky léků   MeSH
• Usnea chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Research on brown adipose tissue and its hallmark protein, mitochondrial uncoupling protein UCP1, has been conducted for half a century and has been traditionally studied in the Institute of Physiology (AS CR, Prague), likewise UCP2 residing in multiple tissues for the last two decades. Our group has significantly contributed to the elucidation of UCP uncoupling mechanism, fully dependent on free fatty acids (FFAs) within the inner mitochondrial membrane. Now we review UCP2 physiological roles emphasizing its roles in pancreatic beta-cells, such as antioxidant role, possible tuning of redox homeostasis (consequently UCP2 participation in redox regulations), and fine regulation of glucose-stimulated insulin secretion (GSIS). For example, NADPH has been firmly established as being a modulator of GSIS and since UCP2 may influence redox homeostasis, it likely affects NADPH levels. We also point out the role of phospholipase iPLA2 isoform gamma in providing FFAs for the UCP2 antioxidant function. Such initiation of mild uncoupling hypothetically precedes lipotoxicity in pancreatic beta-cells until it reaches the pathological threshold, after which the antioxidant role of UCP2 can be no more cell-protective, for example due to oxidative stress-accumulated mutations in mtDNA. These mechanisms, together with impaired autocrine insulin function belong to important causes of Type 2 diabetes etiology.

• MeSH
• antioxidancia metabolismus   MeSH
• beta-buňky metabolismus   MeSH
• glukosa metabolismus   MeSH
• inzulin biosyntéza   MeSH
• iontové kanály metabolismus   MeSH
• kultivované buňky MeSH
• lidé MeSH
• mitochondriální proteiny metabolismus   MeSH
• mitochondrie metabolismus   MeSH
• oxidace-redukce MeSH
• oxidační stres fyziologie   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• regulace genové exprese fyziologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

Arabidopsis MPK4 and MPK6 are implicated in different signalling pathways responding to diverse external stimuli. This was recently correlated with transcriptomic profiles of Arabidopsis mpk4 and mpk6 mutants, and thus it should be reflected also on the level of constitutive proteomes. Therefore, we performed a shot gun comparative proteomic analysis of Arabidopsis mpk4 and mpk6 mutant roots. We have used bioinformatic tools and propose several new proteins as putative MPK4 and MPK6 phosphorylation targets. Among these proteins in the mpk6 mutant were important modulators of development such as CDC48A and phospholipase D alpha 1. In the case of the mpk4 mutant transcriptional reprogramming might be mediated by phosphorylation and change in the abundance of mRNA decapping complex VCS. Further comparison of mpk4 and mpk6 root differential proteomes showed differences in the composition and regulation of defense related proteins. The mpk4 mutant showed altered abundances of antioxidant proteins. The examination of catalase activity in response to oxidative stress revealed that this enzyme might be preferentially regulated by MPK4. Finally, we proposed developmentally important proteins as either directly or indirectly regulated by MPK4 and MPK6. These proteins contribute to known phenotypic defects in the mpk4 and mpk6 mutants.

• MeSH
• Arabidopsis enzymologie   genetika   MeSH
• fosforylace MeSH
• fyziologický stres MeSH
• genová ontologie MeSH
• genový knockout MeSH
• katalasa metabolismus   MeSH
• kořeny rostlin enzymologie   genetika   MeSH
• missense mutace MeSH
• mitogenem aktivované proteinkinasy genetika   MeSH
• peroxidasa metabolismus   MeSH
• posttranslační úpravy proteinů MeSH
• proteiny huseníčku genetika   metabolismus   MeSH
• proteom metabolismus   MeSH
• proteomika MeSH
• receptory pro aktivovanou kinasu C metabolismus   MeSH
• sekvence aminokyselin MeSH
• vazba proteinů MeSH
• vazebná místa MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• srovnávací studie MeSH

Chronic hypoxia and exercise are natural stimuli that confer sustainable cardioprotection against ischemia-reperfusion (I/R) injury, but it is unknown whether they can act in synergy to enhance ischemic resistance. Inflammatory response mediated by tumor necrosis factor-α (TNF-α) plays a role in the infarct size limitation by continuous normobaric hypoxia (CNH), whereas exercise is associated with anti-inflammatory effects. This study was conducted to determine if exercise training performed under conditions of CNH (12% O2) affects myocardial ischemic resistance with respect to inflammatory and redox status. Adult male Wistar rats were assigned to one of the following groups: normoxic sedentary, normoxic trained, hypoxic sedentary, and hypoxic trained. ELISA and Western blot analysis, respectively, were used to quantify myocardial cytokines and the expression of TNF-α receptors, nuclear factor-κB (NF-κB), and selected components of related signaling pathways. Infarct size and arrhythmias were assessed in open-chest rats subjected to I/R. CNH increased TNF-α and interleukin-6 levels and the expression of TNF-α type 2 receptor, NF-κB, inducible nitric oxide synthase (iNOS), cytosolic phospholipase A2α, cyclooxygenase-2, manganese superoxide dismutase (MnSOD), and catalase. None of these effects occurred in the normoxic trained group, whereas exercise in hypoxia abolished or significantly attenuated CNH-induced responses, except for NF-κB, iNOS, and MnSOD. Both CNH and exercise reduced infarct size, but their combination provided the same degree of protection as CNH alone. In conclusion, exercise training does not amplify the cardioprotection conferred by CNH. High ischemic tolerance of the CNH hearts persists after exercise, possibly by maintaining the increased antioxidant capacity despite attenuating TNF-α-dependent protective signaling.NEW & NOTEWORTHYChronic hypoxia and regular exercise are natural stimuli that confer sustainable myocardial protection against acute ischemia-reperfusion injury. Signaling mediated by TNF-α via its type 2 receptor plays a role in the cardioprotective mechanism of chronic hypoxia. In the present study, we found that exercise training of rats during adaptation to hypoxia does not amplify the infarct size-limiting effect. Ischemia-resistant phenotype is maintained in the combined hypoxia-exercise setting despite exercise-induced attenuation of TNF-α-dependent protective signaling.

• MeSH
• cyklooxygenasa 2 metabolismus   MeSH
• fyzická vytrvalost fyziologie   MeSH
• fyziologická adaptace fyziologie   MeSH
• hypoxie metabolismus   patologie   MeSH
• interleukin-6 metabolismus   MeSH
• kondiční příprava zvířat fyziologie   MeSH
• krysa rodu rattus MeSH
• myokard metabolismus   patologie   MeSH
• NF-kappa B metabolismus   MeSH
• potkani Wistar MeSH
• receptory TNF - typ II metabolismus   MeSH
• reperfuzní poškození myokardu metabolismus   patofyziologie   MeSH
• superoxiddismutasa metabolismus   MeSH
• synthasa oxidu dusnatého, typ II metabolismus   MeSH
• TNF-alfa metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Aberrant glycosylation, which impairs recognition capability of NK cells or modifies recognition pattern of target cells, is associated with cancer. Synthetic glycoconjugates (GCs), which modulate cell glycosylation, increase the sensitivity of tumor cells to therapy or boost anti-cancer immune response. In the current study, we employed N-acetyl-D-glucosamine-calix[4]arene (GN4C) as a modulator of cell glycosylation of NK cells represented by the NK-92 cell line and fresh human NK cells. For the first time, we have demonstrated that calix[4]arene-based GC down-regulated the expression of glycosyltransferases MGAT3 and MGAT5 in NK-92 and fresh NK cells. GN4C increased the susceptibility of tumor cells to cytotoxicity by purified fresh NK cells or NK-92 cells. This functional activation of NK cells and the NK-92 cell line correlated with an increased expression of NKG2D mRNA. In the NK-92 cell line, GN4C induced the synthesis of IL-2, IFN-gamma and tumor necrosis factor-alpha as well. Cellular signaling triggered by GN4C engaged PI3-kinase/ERK but not phospholipase C-gamma/JNK pathways. Simultaneously, in transformed NK-92 cells, GN4C reduced the rate of proliferation and down-regulated the c-MYC, EGF-receptor 1 and REL-A molecules. In conclusion, the modulation of glycosyltransferases MGAT3 and MGAT5 by synthetic GN4C correlated with the improvement of NK cell effector functions and the augmentation of tumor cells sensitivity to NK cell-mediated cytotoxicity.

• MeSH
• acyltransferasy imunologie   metabolismus   MeSH
• aktivace lymfocytů imunologie   MeSH
• buněčné linie MeSH
• buňky HT-29 MeSH
• buňky NK imunologie   metabolismus   MeSH
• cytotoxicita imunologická genetika   imunologie   MeSH
• exprese genu MeSH
• fosfatidylinositol-3-kinasy imunologie   metabolismus   MeSH
• glykokonjugáty imunologie   metabolismus   MeSH
• glykosylace MeSH
• lidé MeSH
• messenger RNA analýza   MeSH
• N-acetylglukosaminyltransferasy imunologie   metabolismus   MeSH
• nádory genetika   imunologie   metabolismus   MeSH
• polymerázová řetězová reakce s reverzní transkripcí MeSH
• proliferace buněk MeSH
• proteiny nervové tkáně imunologie   metabolismus   MeSH
• průtoková cytometrie MeSH
• regulace genové exprese u nádorů MeSH
• sekvenční analýza hybridizací s uspořádaným souborem oligonukleotidů MeSH
• separace buněk MeSH
• signální transdukce imunologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH