We asked whether acute redox signaling from mitochondria exists concomitantly to fatty acid- (FA-) stimulated insulin secretion (FASIS) at low glucose by pancreatic β-cells. We show that FA β-oxidation produces superoxide/H2O2, providing: i) mitochondria-to-plasma-membrane redox signaling, closing KATP-channels synergically with elevated ATP (substituting NADPH-oxidase-4-mediated H2O2-signaling upon glucose-stimulated insulin secretion); ii) activation of redox-sensitive phospholipase iPLA2γ/PNPLA8, cleaving mitochondrial FAs, enabling metabotropic GPR40 receptors to amplify insulin secretion (IS). At fasting glucose, palmitic acid stimulated IS in wt mice; palmitic, stearic, lauric, oleic, linoleic, and hexanoic acids also in perifused pancreatic islets (PIs), with suppressed 1st phases in iPLA2γ/PNPLA8-knockout mice/PIs. Extracellular/cytosolic H2O2-monitoring indicated knockout-independent redox signals, blocked by mitochondrial antioxidant SkQ1, etomoxir, CPT1 silencing, and catalase overexpression, all inhibiting FASIS, keeping ATP-sensitive K+-channels open, and diminishing cytosolic [Ca2+]-oscillations. FASIS in mice was a postprandially delayed physiological event. Redox signals of FA β-oxidation are thus documented, reaching the plasma membrane, essentially co-stimulating IS.

• Klíčová slova
• Fatty acid-stimulated insulin secretion, GPR40, Mitochondrial fatty acids, Pancreatic β-cells, Redox signaling, Redox-activated phospholipase iPLA2γ,
• MeSH
• beta-buňky * metabolismus   MeSH
• buněčná membrána * metabolismus   MeSH
• fosfolipasy A2, skupina VI metabolismus   genetika   MeSH
• glukosa metabolismus   MeSH
• inzulin metabolismus   MeSH
• mastné kyseliny * metabolismus   MeSH
• mitochondrie * metabolismus   MeSH
• myši knockoutované MeSH
• myši MeSH
• oxidace-redukce * MeSH
• peroxid vodíku metabolismus   MeSH
• receptory spřažené s G-proteiny MeSH
• sekrece inzulinu * MeSH
• signální transdukce * MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• Ffar1 protein, mouse MeSH Prohlížeč
• fosfolipasy A2, skupina VI MeSH
• glukosa MeSH
• inzulin MeSH
• mastné kyseliny * MeSH
• peroxid vodíku MeSH
• Pla2g6 protein, mouse MeSH Prohlížeč
• receptory spřažené s G-proteiny MeSH

Peroxiredoxin 6 (Prdx6) is a multifunctional enzyme, a unique member of the peroxiredoxin family, with an important role in antioxidant defense. Moreover, it has also been linked with the biosynthesis of anti-inflammatory and anti-diabetic lipids called fatty acid esters of hydroxy fatty acids (FAHFAs) and many diseases, including cancer, inflammation, and metabolic disorders. Here, we performed metabolomic and lipidomic profiling of subcutaneous adipose tissue from mouse models with genetically modified Prdx6. Deletion of Prdx6 resulted in reduced levels of FAHFAs containing 13-hydroxylinoleic acid (13-HLA). Mutation of Prdx6 C47S impaired the glutathione peroxidase activity and reduced FAHFA levels, while D140A mutation, responsible for phospholipase A2 activity, showed only minor effects. Targeted analysis of oxidized phospholipids and triacylglycerols in adipocytes highlighted a correlation between FAHFA and hydroxy fatty acid production by Prdx6 or glutathione peroxidase 4. FAHFA regioisomer abundance was negatively affected by the Prdx6 deletion, and this effect was more pronounced in longer and more unsaturated FAHFAs. The predicted protein model of Prdx6 suggested that the monomer-dimer transition mechanism might be involved in the repair of longer-chain peroxidized phospholipids bound over two monomers and that the role of Prdx6 in FAHFA synthesis might be restricted to branching positions further from carbon 9. In conclusion, our work linked the peroxidase activity of Prdx6 with the levels of FAHFAs in adipose tissue.

• Klíčová slova
• Adipose tissue, FAHFA, Linoleic acid, Lipid oxidation, Peroxiredoxin,
• MeSH
• antioxidancia MeSH
• fosfolipidy MeSH
• mastné kyseliny MeSH
• metabolomika * MeSH
• myši MeSH
• peroxiredoxin VI * genetika   MeSH
• peroxiredoxiny MeSH
• tukové buňky MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antioxidancia MeSH
• fosfolipidy MeSH
• mastné kyseliny MeSH
• peroxiredoxin VI * MeSH
• peroxiredoxiny MeSH

Cellular senescence is a complex stress response defined as an essentially irreversible cell cycle arrest mediated by the inhibition of cell cycle-specific cyclin dependent kinases. The imbalance in redox homeostasis and oxidative stress have been repeatedly observed as one of the hallmarks of the senescent phenotype. However, a large-scale study investigating protein oxidation and redox signaling in senescent cells in vitro has been lacking. Here we applied a proteome-wide analysis using SILAC-iodoTMT workflow to quantitatively estimate the level of protein sulfhydryl oxidation and proteome level changes in ionizing radiation-induced senescence (IRIS) in hTERT-RPE-1 cells. We observed that senescent cells mobilized the antioxidant system to buffer the increased oxidation stress. Among the antioxidant proteins with increased relative abundance in IRIS, a unique 1-Cys peroxiredoxin family member, peroxiredoxin 6 (PRDX6), was identified as an important contributor to protection against oxidative stress. PRDX6 silencing increased ROS production in senescent cells, decreased their resistance to oxidative stress-induced cell death, and impaired their viability. Subsequent SILAC-iodoTMT and secretome analysis after PRDX6 silencing showed the downregulation of PRDX6 in IRIS affected protein secretory pathways, decreased expression of extracellular matrix proteins, and led to unexpected attenuation of senescence-associated secretory phenotype (SASP). The latter was exemplified by decreased secretion of pro-inflammatory cytokine IL-6 which was also confirmed after treatment with an inhibitor of PRDX6 iPLA2 activity, MJ33. In conclusion, by combining different methodological approaches we discovered a novel role of PRDX6 in senescent cell viability and SASP development. Our results suggest PRDX6 could have a potential as a drug target for senolytic or senomodulatory therapy.

• Klíčová slova
• Cellular senescence, Interleukin 6, Peroxiredoxin 6, Redox proteomics, SILAC-iodoTMT, Senescence-associated secretory phenotype,
• MeSH
• cytokiny * metabolismus   MeSH
• oxidace-redukce MeSH
• oxidační stres MeSH
• peroxiredoxin VI * genetika   metabolismus   MeSH
• stárnutí buněk fyziologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• cytokiny * MeSH
• peroxiredoxin VI * MeSH

The patatin-like phospholipase domain containing 3 (PNPLA3) gene (viz. its I148M variant) is one of the key players in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). We have identified a novel insertion/deletion variant of 1114 bp, localized in the second intron of the PNPLA3 gene, which corresponds to the 3' terminal sequence of the long-interspersed element (LINE-1). DNA analysis of 122 NAFLD patients and 167 control subjects as well as RNA analysis of 19 liver biopsies revealed that the novel variant is very common (frequency = 0.41), fully linked to the clinically important I148M variant, and clinically silent. Although the LINE-1 insertion does not seem to have any biological effect, it can impede genotyping of the I148M variant. If insertion prevents the attachment of the diagnostic primer, then the non-insertion allele will be selectively amplified; and thus the frequency of the 148M "risk" allele will be significantly overestimated due to the complete linkage of the LINE-1 insertion and the 148I allele of the PNPLA3 gene. Therefore, our findings underline the importance of careful design and consistent documentation of the methodology, including primer sequences. Critical revisions of the results of some studies that have already been reported may therefore be needed.

• MeSH
• acyltransferasy genetika   MeSH
• alely MeSH
• dlouhé rozptýlené jaderné elementy genetika   MeSH
• fosfolipasy A2 nezávislé na vápníku genetika   MeSH
• genetická predispozice k nemoci genetika   MeSH
• genotyp MeSH
• játra patologie   MeSH
• jednonukleotidový polymorfismus genetika   MeSH
• lidé MeSH
• nealkoholová steatóza jater genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• acyltransferasy MeSH
• adiponutrin, human MeSH Prohlížeč
• fosfolipasy A2 nezávislé na vápníku MeSH

The human iPSC cell lines, PLANFiPS1-Sv4F-1 (RCPFi004-A), PLANFiPS2-Sv4F-1 (RCPFi005-A), PLANFiPS3-Sv4F-1 RCPFi006-A), derived from dermal fibroblast from three patients suffering PLAN (PLA2G6-associated neurodegeneration; MIM 256600) caused by mutations in the PLA2G6 gene, was generated by non-integrative reprogramming technology using OCT3/4, SOX2, CMYC and KLF4 reprogramming factors. The pluripotency was assessed by immunocytochemistry and RT-PCR. Differentiation capacity was verified in vitro. This iPSC line can be further differentiated toward affected cells to better understand molecular mechanisms of disease and pathophysiology.

• MeSH
• buněčná diferenciace MeSH
• buněčné linie MeSH
• fosfolipasy A2, skupina VI MeSH
• indukované pluripotentní kmenové buňky * MeSH
• Krüppel-like faktor 4 MeSH
• lidé MeSH
• mutace MeSH
• neuroaxonální dystrofie * MeSH
• přeprogramování buněk MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• fosfolipasy A2, skupina VI MeSH
• KLF4 protein, human MeSH Prohlížeč
• Krüppel-like faktor 4 MeSH
• PLA2G6 protein, human MeSH Prohlížeč

The relationship between baroreflex sensitivity (BRS) and inflammatory vascular biomarker Lipoprotein associated phospholipase A2 (Lp-PLA2) in subjects with high normal blood pressure (HNBP, prehypertensives) with a positive family history of hypertension (FHH+) and hypertension history free control subjects (FHH-) was evaluated. A total of 24 HNBP participants (age 39.5 ± 2.5 years, 18 male/ 6 female) were studied. 14 HNBP subjects FHH+ were compared to 10 HNBP participants FHH-, being of similar age and body mass index. BRS (ms/mmHg) was determined by the sequence and spectral methods (five-minute non-invasive beat-to-beat recording of blood pressure and RR interval, controlled breathing at a frequency of 0.33 Hz). Venous blood was analyzed for Lp-PLA2 biomarker of vascular inflammation and atherothrombotic activity. A significant negative correlation between spontaneous BRS obtained by both methods and systolic blood pressure (BP) was present (BRS spect r = -0.54, P<0.001, BRS seq r = -0.59, P<0.001). BRS obtained by sequence and spectral methods were reduced in HNBP FHH+ compared to the group of HNBP FHH- (P = 0.0317 BRS seq, P = 0.0395 BRS spect). Lp-PLA2 was significantly higher in HNBP FHH+ compared to FHH- controls (P<0.05). Lp-PLA2 was negatively correlated with BRS obtained by sequence method (r = -0.798, R2 = 0.636, P<0.001) in the HNBP FHH+ subjects. These findings demonstrate that reduced baroreflex sensitivity, as a marker of autonomic dysfunction, is associated with vascular inflammation, predominantly in otherwise healthy participants with a positive family history of hypertension who could predispose to increased risk of hypertension. We conclude that our transversal study suggests that a lowbaroreflex sensitivity could be an early sign of autonomic dysfunction even in the prehypertensive period, and to corroborate these findings, a longitudinal study is needed.

• MeSH
• 1-alkyl-2-acetylglycerofosfocholinesterasa krev   MeSH
• anamnéza MeSH
• autonomní nervový systém patofyziologie   MeSH
• baroreflex * MeSH
• biologické markery krev   MeSH
• dospělí MeSH
• hypertenze krev   diagnóza   enzymologie   patofyziologie   MeSH
• krevní tlak * MeSH
• lidé středního věku MeSH
• lidé MeSH
• prediktivní hodnota testů MeSH
• rizikové faktory MeSH
• studie případů a kontrol MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• 1-alkyl-2-acetylglycerofosfocholinesterasa MeSH
• biologické markery MeSH
• PLA2G7 protein, human MeSH Prohlížeč

Obesity is believed to be associated with a dysregulated endocannabinoid system which may reflect enhanced inflammation. However, reports of this in human white adipose tissue (WAT) are limited and inconclusive. Marine long-chain omega-3 polyunsaturated fatty acids (LC n-3 PUFAs) have anti-inflammatory actions and therefore may improve obesity-associated adipose tissue inflammation. Therefore, fatty acid (FA) concentrations, endocannabinoid concentrations, and gene expression were assessed in subcutaneous WAT (scWAT) biopsies from healthy normal weight individuals (BMI 18.5-25 kg/m2) and individuals living with metabolically healthy obesity (BMI 30-40 kg/m2) prior to and following a 12-week intervention with 3 g fish oil/day (1.1 g eicosapentaenoic acid (EPA) + 0.8 g DHA) or 3 g corn oil/day (placebo). WAT from individuals living with metabolically healthy obesity had higher n-6 PUFAs and EPA, higher concentrations of two endocannabinoids (anandamide (AEA) and eicosapentaenoyl ethanolamide (EPEA)), higher expression of phospholipase A2 Group IID (PLA2G2D) and phospholipase A2 Group IVA (PLA2G4A), and lower expression of CNR1. In response to fish oil intervention, WAT EPA increased to a similar extent in both BMI groups, and WAT DHA increased by a greater extent in normal weight individuals. WAT EPEA and docosahexaenoyl ethanolamide (DHEA) increased in normal weight individuals only and WAT 2-arachidonyl glycerol (2-AG) decreased in individuals living with metabolically healthy obesity only. Altered WAT fatty acid, endocannabinoid, and gene expression profiles in metabolically healthy obesity at baseline may be linked. WAT incorporates n-3 PUFAs when their intake is increased which affects the endocannabinoid system; however, effects appear greater in normal weight individuals than in those living with metabolically healthy obesity.

• Klíčová slova
• LC n-3 PUFA, adipose tissue, endocannabinoids, lipids, obesity,
• MeSH
• časové faktory MeSH
• dospělí MeSH
• dvojitá slepá metoda MeSH
• endokanabinoidy metabolismus   MeSH
• fixní kombinace léků MeSH
• fosfolipasy A2, skupina II metabolismus   MeSH
• fosfolipasy A2, skupina IV metabolismus   MeSH
• kyselina eikosapentaenová aplikace a dávkování   MeSH
• kyseliny arachidonové metabolismus   MeSH
• kyseliny dokosahexaenové aplikace a dávkování   MeSH
• lidé středního věku MeSH
• lidé MeSH
• metabolicky zdravá obezita diagnóza   farmakoterapie   metabolismus   MeSH
• mladiství MeSH
• mladý dospělý MeSH
• podkožní tuk účinky léků   metabolismus   MeSH
• polynenasycené alkamidy metabolismus   MeSH
• potravní doplňky * MeSH
• receptor kanabinoidní CB1 metabolismus   MeSH
• výsledek terapie MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• randomizované kontrolované studie MeSH
• Geografické názvy
• Anglie MeSH
• Názvy látek
• anandamide MeSH Prohlížeč
• CNR1 protein, human MeSH Prohlížeč
• endokanabinoidy MeSH
• fixní kombinace léků MeSH
• fosfolipasy A2, skupina II MeSH
• fosfolipasy A2, skupina IV MeSH
• kyselina eikosapentaenová MeSH
• kyseliny arachidonové MeSH
• kyseliny dokosahexaenové MeSH
• N-docosahexaenoylethanolamide MeSH Prohlížeč
• PLA2G2D protein, human MeSH Prohlížeč
• PLA2G4A protein, human MeSH Prohlížeč
• polynenasycené alkamidy MeSH
• receptor kanabinoidní CB1 MeSH

To date, the effects of specific modification types and sites on protein lifetime have not been systematically illustrated. Here, we describe a proteomic method, DeltaSILAC, to quantitatively assess the impact of site-specific phosphorylation on the turnover of thousands of proteins in live cells. Based on the accurate and reproducible mass spectrometry-based method, a pulse labeling approach using stable isotope-labeled amino acids in cells (pSILAC), phosphoproteomics, and a unique peptide-level matching strategy, our DeltaSILAC profiling revealed a global, unexpected delaying effect of many phosphosites on protein turnover. We further found that phosphorylated sites accelerating protein turnover are functionally selected for cell fitness, enriched in Cyclin-dependent kinase substrates, and evolutionarily conserved, whereas the glutamic acids surrounding phosphosites significantly delay protein turnover. Our method represents a generalizable approach and provides a rich resource for prioritizing the effects of phosphorylation sites on protein lifetime in the context of cell signaling and disease biology.

• Klíčová slova
• DeltaSILAC, data-independent acquisition, mass spectrometry, phosphomodiform, phosphorylation, protein lifetime, protein turnover, proteomics, pulse SILAC,
• MeSH
• buněčný cyklus fyziologie   MeSH
• cyklin-dependentní kinasy genetika   metabolismus   MeSH
• fosfoproteiny chemie   metabolismus   MeSH
• fosforylace MeSH
• glutamáty metabolismus   MeSH
• hmotnostní spektrometrie metody   MeSH
• izotopové značení metody   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• peptidy metabolismus   MeSH
• peroxiredoxin VI chemie   metabolismus   MeSH
• proteolýza * MeSH
• proteom genetika   metabolismus   MeSH
• proteomika metody   MeSH
• sekvence aminokyselin MeSH
• sestřihové faktory chemie   metabolismus   MeSH
• signální transdukce genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• cyklin-dependentní kinasy MeSH
• fosfoproteiny MeSH
• glutamáty MeSH
• peptidy MeSH
• peroxiredoxin VI MeSH
• PRDX6 protein, human MeSH Prohlížeč
• proteom MeSH
• sestřihové faktory MeSH
• SF3B1 protein, human MeSH Prohlížeč

• MeSH
• alergeny aplikace a dávkování   imunologie   MeSH
• alergie diagnóza   imunologie   MeSH
• biologické markery krev   MeSH
• dítě MeSH
• dospělí MeSH
• fosfolipasy A aplikace a dávkování   imunologie   MeSH
• hmyzí proteiny aplikace a dávkování   imunologie   MeSH
• imunoglobulin E krev   MeSH
• imunologické testy * MeSH
• kousnutí a bodnutí hmyzem diagnóza   imunologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• prediktivní hodnota testů MeSH
• rekombinantní proteiny aplikace a dávkování   imunologie   MeSH
• retrospektivní studie MeSH
• senioři MeSH
• včelí jedy imunologie   MeSH
• vosí jedy imunologie   MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• dopisy MeSH
• multicentrická studie MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH
• Slovinsko MeSH
• Názvy látek
• alergeny MeSH
• Api m 1 allergen, Apis mellifera MeSH Prohlížeč
• biologické markery MeSH
• fosfolipasy A MeSH
• hmyzí proteiny MeSH
• imunoglobulin E MeSH
• rekombinantní proteiny MeSH
• včelí jedy MeSH
• Ves v 5 allergen MeSH Prohlížeč
• vosí jedy MeSH

The inflammatory process is a natural self-defense response of the organism to damage agents and its action mechanism involves a series of complex reactions. However, in some cases, this process can become chronic, causing much harm to the body. Therefore, over the years, many anti-inflammatory drugs have been developed aiming to decrease the concentrations of inflammatory mediators in the organism, which is a way of controlling these abnormal chain reactions. The main target of conventional anti-inflammatory drugs is the cyclooxygenase (COX) enzyme, but its use implies several side effects. Thus, based on these limitations, many studies have been performed, aiming to create new drugs, with new action mechanisms. In this sense, the phospholipase A2 (PLA2) enzymes stand out. Among all the existing isoforms, secretory PLA2 is the major target for inhibitor development, since many studies have proven that this enzyme participates in various inflammatory conditions, such as cancer, Alzheimer and arthritis. Finally, for the purpose of developing anti-inflammatory drugs that are sPLA2 inhibitors, many molecules have been designed. Accordingly, this work presents an overview of inflammatory processes and mediators, the current available anti-inflammatory drugs, and it briefly covers the PLA2 enzymes, as well as the diverse structural array of the newest sPLA2 inhibitors as a possible target for the production of new anti-inflammatory drugs.

• Klíčová slova
• Phospholipases A2, anti-inflammatory drugs, drug design, enzymatic inhibitors, inflammation, newest patents.,
• MeSH
• antiflogistika farmakologie   MeSH
• cyklooxygenasa 2 MeSH
• fosfolipasy A2 MeSH
• inhibitory enzymů MeSH
• inhibitory fosfolipasy A2 MeSH
• lidé MeSH
• nádory MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• antiflogistika MeSH
• cyklooxygenasa 2 MeSH
• fosfolipasy A2 MeSH
• inhibitory enzymů MeSH
• inhibitory fosfolipasy A2 MeSH