Search

It remains largely unclear how thymocytes translate relative differences in T cell receptor (TCR) signal strength into distinct developmental programs that drive the cell fate decisions towards conventional (Tconv) or regulatory T cells (Treg). Following TCR activation, intracellular calcium (Ca2+) is the most important second messenger, for which the potassium channel K2P18.1 is a relevant regulator. Here, we identify K2P18.1 as a central translator of the TCR signal into the thymus-derived Treg (tTreg) selection process. TCR signal was coupled to NF-κB-mediated K2P18.1 upregulation in tTreg progenitors. K2P18.1 provided the driving force for sustained Ca2+ influx that facilitated NF-κB- and NFAT-dependent expression of FoxP3, the master transcription factor for Treg development and function. Loss of K2P18.1 ion-current function induced a mild lymphoproliferative phenotype in mice, with reduced Treg numbers that led to aggravated experimental autoimmune encephalomyelitis, while a gain-of-function mutation in K2P18.1 resulted in increased Treg numbers in mice. Our findings in human thymus, recent thymic emigrants and multiple sclerosis patients with a dominant-negative missense K2P18.1 variant that is associated with poor clinical outcomes indicate that K2P18.1 also plays a role in human Treg development. Pharmacological modulation of K2P18.1 specifically modulated Treg numbers in vitro and in vivo. Finally, we identified nitroxoline as a K2P18.1 activator that led to rapid and reversible Treg increase in patients with urinary tract infections. Conclusively, our findings reveal how K2P18.1 translates TCR signals into thymic T cell fate decisions and Treg development, and provide a basis for the therapeutic utilization of Treg in several human disorders.

The Food Chain Plus (FoCus) cohort was launched in 2011 for population-based research related to metabolic inflammation. To characterize this novel pathology in a comprehensive manner, data collection included multiple omics layers such as phenomics, microbiomics, metabolomics, genomics, and metagenomics as well as nutrition profiling, taste perception phenotyping and social network analysis. The cohort was set-up to represent a Northern German population of the Kiel region. Two-step recruitment included the randomised enrolment of participants via residents’ registration offices and via the Obesity Outpatient Centre of the University Medical Center Schleswig–Holstein (UKSH). Hence, both a population- and metabolic inflammation- based cohort was created. In total, 1795 individuals were analysed at baseline. Baseline data collection took place between 2011 and 2014, including 63% females and 37% males with an age range of 18–83 years. The median age of all participants was 52.0 years [IQR: 42.5; 63.0 years] and the median baseline BMI in the study population was 27.7 kg/m2 [IQR: 23.7; 35.9 kg/m2]. In the baseline cohort, 14.1% of participants had type 2 diabetes mellitus, which was more prevalent in the subjects of the metabolic inflammation group (MIG; 31.8%). Follow-up for the assessment of disease progression, as well as the onset of new diseases with changes in subject’s phenotype, diet or lifestyle factors is planned every 5 years. The first follow-up period was finished in 2020 and included 820 subjects.

Die Festschrift zeichnet die Entwicklung der Agrar- und Ernährungswissenschaftlichen Fakultät der Christian-Albrechts-Universität zu Kiel von ihrer Vorgeschichte bis zur Gegenwart nach. Gezeigt wird der Wandel der Instituts- und Forschungsstruktur ebenso wie der Weg vom einstigen Landwirtschafts- zum heutigen Bachelor- und Masterstudium der Agrar- und Ernährungswissenschaften. Von der Phase der Ernährungssicherung nach dem Zweiten Weltkrieg bis zu den aktuellen vernetzten Forschungsgebieten haben sich Agrarökonomie, Ernährungs-, Nutzpflanzen-, Nutztier- und Umweltwissenschaften in den vergangenen 75 Jahren stark verändert. Damals wie heute sind sie gleichwohl gesellschaftlich hochrelevante Leuchttürme der Forschung im hohen Norden.

Chloroform has been used over decades in anesthesia before it was replaced by other volatile anesthetics like halothane or sevoflurane. Some of the reasons were inadmissible side effects of chloroform like bradycardia or neural illness. In the present study, we identified members of the G protein-activated inwardly rectifying potassium channel family (Kir3) expressed in Xenopus oocytes as potential common molecular targets for both the neural and cardiac effects of chloroform. Millimolar concentration currents representing a 1:10000 dilution of commercially available chloroform were used in laboratories that augment neuronal Kir3.1/3.2 currents as well as cardiac Kir3.1/3.4. This effect was selective and only observed in currents from Kir3 subunits but not in currents from Kir2 subunits. Augmentation of atrial Kir3.1/3.4 currents leads to an effective drop of the heart rate and a reduction in contraction force in isolated mouse atria.

Adjusting the efficiency of movement in response to environmental cues is an essential integrative characteristic of adaptive locomotion behavior across species. However, the modulatory molecules and the pathways involved are largely unknown. Recently, we demonstrated that in Caenorhabditis elegans, a loss-of-function of the two-pore-domain potassium (K2P) channel TWK-7 causes a fast, coordinated, and persistent forward crawling behavior in which five central aspects of stimulated locomotion—velocity, direction, wave parameters, duration, and straightness—are affected. Here, we isolated the reduction-of-function allele cau1 of the C. elegans gene kin-2 in a forward genetic screen and showed that it phenocopies the locomotor activity and locomotion behavior of twk-7(null) animals. Kin-2 encodes the negative regulatory subunit of protein kinase A (KIN-1/PKA). Consistently, we found that other gain-of-function mutants of the GαS-KIN-1/PKA pathway resemble kin-2(cau1) and twk-7(null) in locomotion phenotype. Using the powerful genetics of the C. elegans system in combination with cell type-specific approaches and detailed locomotion analyses, we identified TWK-7 as a putative downstream target of the GαS-KIN-1/PKA pathway at the level of the γ-aminobutyric acid (GABA)ergic D-type motor neurons. Due to this epistatic interaction, we suggest that KIN-1/PKA and TWK-7 may share a common pathway that is probably involved in the modulation of both locomotor activity and locomotion behavior during forward crawling.

The suitability of C. elegans as a model for the question of nutritional science is a controversial topic. The discussion makes clear that C. elegans is its own best model for revealing, via genetic approaches, biological principles of nutritional behavior, and the biochemical function of vitamins. In this case, the model has a discovery function. Worm research serves also in the identification of nutrition-dependent pathways that could be used for novel approaches in human nutritional studies. This heuristic function of the model guides the applied nutrition research in an innovative direction. Since the nutrition and metabolism for the worm and man differ from each other somewhat strongly, results of nutritional studies in C. elegans are not directly applicable to human nutrition. In general, the C. elegans model is primarily appropriate for explaining the causality of general species’ nutritional phenotypes. Experience tells us that the analysis of drastic nutritional phenotypes in C. elegans has the potential to enrich the canon of knowledge of nutritional science.

The change of locomotion activity in response to external cues is a considerable achievement of animals and is required for escape responses, foraging, and other complex behaviors. Little is known about the molecular regulators of such an adaptive locomotion. The conserved eukaryotic two-pore domain potassium (K2P) channels have been recognized as regulatory K+ channels that modify the membrane potential of cells, thereby affecting, e.g., rhythmic muscle activity. By using the Caenorhabditis elegans system combined with cell-type-specific approaches and locomotion in-depth analyses, here, we found that the loss of K2P channel TWK-7 increases the locomotor activity of worms during swimming and crawling in a coordinated mode. Moreover, loss of TWK-7 function results in a hyperactive state that (although less pronounced) resembles the fast, persistent, and directed forward locomotion behavior of stimulated C. elegans. TWK-7 is expressed in several head neurons as well as in cholinergic excitatory and GABAergic inhibitory motor neurons. Remarkably, the abundance of TWK-7 in excitatory B-type and inhibitory D-type motor neurons affected five central aspects of adaptive locomotion behavior: velocity/frequency, wavelength/amplitude, direction, duration, and straightness. Hence, we suggest that TWK-7 activity might represent a means to modulate a complex locomotion behavior at the level of certain types of motor neurons.

Mitragyna speciosa Korth is known for its euphoric properties and is frequently used for recreational purposes. Several poisoning and fatal cases involving mitragynine have been reported but the underlying causes remain unclear. Human ether-a-go-go-related gene (hERG) encodes the cardiac IKr current which is a determinant of the duration of ventricular action potentials and QT interval. On the other hand, IK1, a Kir current mediated by Kir2.1 channel and IKACh, a receptor-activated Kir current mediated by GIRK channel are also known to be important in maintaining the cardiac function. This study investigated the effects of mitragynine on the current, mRNA and protein expression of hERG channel in hERG-transfected HEK293 cells and Xenopus oocytes. The effects on Kir2.1 and GIRK channels currents were also determined in the oocytes. The hERG tail currents following depolarization pulses were inhibited by mitragynine with an IC50 value of 1.62μM and 1.15μM in the transfected cell line and Xenopus oocytes, respectively. The S6 point mutations of Y652A and F656A attenuated the inhibitor effects of mitragynine, indicating that mitragynine interacts with these high affinity drug-binding sites in the hERG channel pore cavity which was consistent with the molecular docking simulation. Interestingly, mitragynine does not affect the hERG expression at the transcriptional level but inhibits the protein expression. Mitragynine is also found to inhibit IKACh current with an IC50 value of 3.32μM but has no significant effects on IK1. Blocking of both hERG and GIRK channels may cause additive cardiotoxicity risks.

Lipids play a pivotal role in embryogenesis as structural components of cellular membranes, as a source of energy, and as signaling molecules. On the basis of a collection of temperature-sensitive embryonic lethal mutants, a systematic database search, and a subsequent microscopic analysis of >300 interference RNA (RNAi)–treated/mutant worms, we identified a couple of evolutionary conserved genes associated with lipid storage in Caenorhabditis elegans embryos. The genes include cpl-1 (cathepsin L–like cysteine protease), ccz-1 (guanine nucleotide exchange factor subunit), and asm-3 (acid sphingomyelinase), which is closely related to the human Niemann-Pick disease–causing gene SMPD1. The respective mutant embryos accumulate enlarged droplets of neutral lipids (cpl-1) and yolk-containing lipid droplets (ccz-1) or have larger genuine lipid droplets (asm-3). The asm-3 mutant embryos additionally showed an enhanced resistance against C band ultraviolet (UV-C) light. Herein we propose that cpl-1, ccz-1, and asm-3 are genes required for the processing of lipid-containing droplets in C. elegans embryos. Owing to the high levels of conservation, the identified genes are also useful in studies of embryonic lipid storage in other organisms.

Coenzyme Q10 (CoQ10) is synthesized in almost all human tissues and presumably involved in age-related alterations and diseases. Here, we examined the impact of aging and sex on the serum CoQ10 status in 860 European adults ranging in age from 18 to 82 years. We identified an inverse U-shaped relationship between CoQ10 concentration and age. Women showed lower cholesterol-adjusted CoQ10 levels than men, irrespective of age. As observed in both sexes, the decrease in CoQ10 concentration in older subjects was accompanied by a shift in the redox status in favour of the oxidized form. A strong positive correlation was found for total CoQ10 and cholesterol concentrations (Spearman’s, p≤1E-74). We found strong negative correlations between total (Spearman’s, p≤1E-07) and between cholesterol-adjusted CoQ10 concentration (Spearman’s, p≤1E-14) and the proportion of the oxidized form of CoQ10. These correlations were not dependent on age and sex and were attenuated by supplementation with 150 mg/day reduced CoQ10 for 14 days. Overall, our results are useful to define risk groups with critical CoQ10 status in humans. In particular, older subjects were characterized by impaired CoQ10 status due to their lowered serum CoQ10 concentration and concomitant decrease of CoQ10 redox capacity.

Introduction Coenzyme Q10 (CoQ10) is a lipophilic endogenously synthesised antioxidant that is present in nearly all human tissues and plays an important role in mitochondrial energy production. It has been postulated that smoking has a consumptive effect on CoQ10. Material and methods To further define the relation between smoking and the serum CoQ10 status, 276 healthy volunteers aged 19 to 62 years were grouped into non-smokers (n = 113; 77 male, 36 female) and smokers (n = 163; 102 male, 61 female). Serum lipid profile was analysed by standard clinical chemistry. Coenzyme Q10 concentration and redox status were analysed by high-pressure liquid chromatography with electrochemical detection. Results Male smokers showed higher serum CoQ10 levels than female smokers. This sex-related difference was accounted for when CoQ10 was related to low-density lipoprotein (LDL) cholesterol as the main carrier of CoQ10 in the circulation. Neither LDL-adjusted CoQ10 concentration nor redox status significantly differed when smokers and non-smokers were compared. Regarding the smoking history, the number of cigarettes consumed per day did not significantly affect the CoQ10 status. Interestingly, with increasing time of smoking habit we observed increasing levels of LDL-adjusted serum CoQ10 concentration (Spearman's p < 0.002) and of the reduced form of CoQ10 (Spearman's p < 0.0001). Conclusions As an adaptive response to oxidative stress in long-term smokers an increased demand for antioxidant capacity may be covered by increasing levels of LDL-adjusted CoQ10 serum concentrations and by a concomitantly increased availability of the reduced, active form of CoQ10, possibly by induction of enzymes that are involved in converting CoQ10ox to CoQ10red.

Fabry disease (FD) is a life-threatening X-linked lysosomal storage disorder caused by α-galactosidase A (α-GAL) deficiency. Small fiber pathology and pain are major FD symptoms of unknown pathophysiology. α-GAL deficient mice (GLA KO) age-dependently accumulate globotriaosylceramide (Gb3) in dorsal root ganglion (DRG) neurons paralleled by endoplasmic stress and apoptosis as contributors to skin denervation. Old GLA KO mice show increased TRPV1 protein in DRG neurons and heat hypersensitivity upon i.pl. capsaicin. In turn, GLA KO mice are protected from heat and mechanical hypersensitivity in neuropathic and inflammatory pain models based on reduced neuronal Ih and Nav1.7 currents. We show that in vitro α-GAL silencing increases intracellular Gb3 accumulation paralleled by loss of Nav1.7 currents, which is reversed by incubation with agalsidase-α and lucerastat. We provide first evidence of a direct Gb3 effect on neuronal integrity and ion channel function as potential mechanism underlying pain and small fiber pathology in FD.

Natural killer (NK) cells are a subset of cytotoxic lymphocytes that recognize and kill tumor- and virus-infected cells without prior stimulation. Killing of target cells is a multistep process including adhesion to target cells, formation of an immunological synapse, and polarization and release of cytolytic granules. The role of distinct potassium channels in this orchestrated process is still poorly understood. The current study reveals that in addition to the voltage-gated KV 1.3 and the calcium-activated KCa 3.1 channels, human NK cells also express the two-pore domain K2 P channel TASK2 (TWIK-related acid-sensitive potassium channel). Expression of Task2 varies among NK-cell subsets and depends on their differentiation and activation state. Despite its different expression in TASK2(high) CD56(bright) CD16(-) and TASK2(low) CD56(dim) CD16(+) NK cells, TASK2 is involved in cytokine-induced proliferation and cytolytic function of both subsets. TASK2 is crucial for leukocyte functional antigen (LFA-1) mediated adhesion of both resting and cytokine-activated NK cells to target cells, an early step in killing of target cells. With regard to the following mechanism, TASK2 plays a role in release of cytotoxic granules by resting, but not IL-15-induced NK cells. Taken together, our data exhibit two-pore potassium channels as important players in NK-cell activation and effector function.

Coenzyme Q10 (CoQ10) exists in a reduced (ubiquinol) and an oxidized (ubiquinone) form in all human tissues and functions, amongst others, in the respiratory chain, redox-cycles, and gene expression. As the status of CoQ10 is an important risk factor for several diseases, here we determined the CoQ10 status (ubiquinol, ubiquinone) in a large Caucasian study population (n = 1,911). The study population covers a wide age range (age: 18–83 years, 43.4% men), has information available on more than 10 measured clinical phenotypes, more than 30 diseases (presence vs. absence), about 30 biomarkers, and comprehensive genetic information including whole-genome SNP typing (>891,000 SNPs). The major aim of this long-term resource in CoQ10 research is the comprehensive analysis of the CoQ10 status with respect to integrated health parameters (i.e., fat metabolism, inflammation), disease-related biomarkers (i.e., liver enzymes, marker for heart failure), common diseases (i.e., neuropathy, myocardial infarction), and genetic risk in humans. Based on disease status, biomarkers, and genetic variants, our cohort is also useful to perform Mendelian randomisation approaches. In conclusion, the present study population is a promising resource to gain deeper insight into CoQ10 status in human health and disease. © 2015 BioFactors, 41(4):211–221, 2015

Coenzyme Q10 (CoQ10) is synthesized in most human tissues, with high concentration in the skeletal muscle. CoQ10 functions in the mitochondrial respiratory chain and serves as a potent liphophilic antioxidant in membranes. CoQ10 deficiency impairs mitochondrial ATP synthesis and increases oxidative stress. It has been suggested that plasma CoQ10 status is not a robust proxy for the diagnosis of CoQ10 deficiency. We determined the concentration and redox-status of CoQ10 in plasma and muscle tissue from 140 healthy children (0.8–15.3 y) by high-performance liquid chromatography (HPLC) with electrochemical detection. There was no correlation between CoQ10 concentration or redox status between plasma and muscle tissue. Lipid-related CoQ10 plasma concentrations showed a negative correlation with age (Spearman’s, P ≤ 0.02), but there was no significant age-related correlation for muscle concentration. In muscle tissue, we found a distinct shift in the redox status in favor of the oxidized proportion with increasing age (Spearman’s, P ≤ 0.00001). Reference values for muscle CoQ10 concentration (40.5 ± 12.2 pmol/mg wet tissue) and CoQ10 redox status (46.8 ± 6.8% oxidized within total) were established for healthy children. The age-related redox shift in muscle tissue suggests changes in antioxidative defense during childhood. The reference values established here provide a necessary prerequisite for diagnosing early CoQ10 deficiency.

Dietary restriction (DR) is a robust intervention that extends both health span and life span in many organisms. Ubiquinol and ubiquinone represent the reduced and oxidized forms of coenzyme Q (CoQ). CoQ plays a central role in energy metabolism and functions in several cellular processes including gene expression. Here we used the model organism Caenorhabditis elegans to determine level and redox state of CoQ and expression of genes in response to DR. We found that DR down-regulates the steady-state expression levels of several evolutionary conserved genes (i.e. coq-1) that encode key enzymes of the mevalonate and CoQ-synthesizing pathways. In line with this, DR decreases the levels of total CoQ and ubiquinol. This CoQ-reducing effect of DR is obvious in adult worms but not in L4 larvae and is also evident in the eat-2 mutant, a genetic model of DR. In conclusion, we propose that DR reduces the level of CoQ and ubiquinol via gene expression in the model organism C. elegans.

Ubiquinone and ubiquinol represent the oxidized and reduced forms of Coenzyme Q10 (CoQ10). CoQ10 is present in membranes of almost all human tissues and organs, with highest concentration in the heart. In patients with heart failure, serum levels of the N-terminal pro-brain natriuretic peptide (NT-proBNP) are an indicator of disease severity. Here, we investigated the relationship between serum levels of CoQ10 and NT-proBNP in healthy volunteers of an elderly study population (mean age 52 years, n = 871). We found a negative association between serum levels of ubiquinol and NT-proBNP (P

Coenzyme Q (CoQ) is necessary for mitochondrial energy production and modulates the expression of genes that are important for inflammatory processes, growth and detoxification reactions. A cellular surveillance-activated detoxification and defenses (cSADDs) pathway has been recently identified in C. elegans. The down-regulation of the components of the cSADDs pathway initiates an aversion behavior of the nematode. Here we hypothesized that CoQ regulates genes of the cSADDs pathway. To verify this we generated CoQ-deficient worms ("CoQ-free") and performed whole-genome expression profiling. We found about 30% (120 genes) of the cSADDs pathway genes were differentially regulated under CoQ-deficient condition. Remarkably, 83% of these genes were down-regulated. The majority of the CoQ-sensitive cSADDs pathway genes encode for proteins involved in larval development (enrichment score (ES) = 38.0, p = 5.0E(-37)), aminoacyl-tRNA biosynthesis, proteasome function (ES 8.2, p = 5.9E(-31)) and mitochondria function (ES 3.4, p = 1.7E(-5)). 67% (80 genes) of these genes are categorized as lethal. Thus it is shown for the first time that CoQ regulates a substantial number of essential genes that function in the evolutionary conserved cellular surveillance-activated detoxification and defenses pathway in C. elegans.

Environmental conditions experienced during animal development are thought to have sustained impact on maturation and adult lifespan. Here we show that in the model organism C. elegans developmental rate and adult lifespan depend on larval population density, and that this effect is mediated by excreted small molecules. By using the time point of first egg laying as a marker for full maturity, we found that wildtype hermaphrodites raised under high density conditions developed significantly faster than animals raised in isolation. Population density-dependent acceleration of development (Pdda) was dramatically enhanced in fatty acid β-oxidation mutants that are defective in the biosynthesis of ascarosides, small-molecule signals that induce developmental diapause. In contrast, Pdda is abolished by synthetic ascarosides and steroidal ligands of the nuclear hormone receptor DAF-12. We show that neither ascarosides nor any known steroid hormones are required for Pdda and that another chemical signal mediates this phenotype, in part via the nuclear hormone receptor NHR-8. Our results demonstrate that C. elegans development is regulated by a push-pull mechanism, based on two antagonistic chemical signals: chemosensation of ascarosides slows down development, whereas population-density dependent accumulation of a different chemical signal accelerates development. We further show that the effects of high larval population density persist through adulthood, as C. elegans larvae raised at high densities exhibit significantly reduced adult lifespan and respond differently to exogenous chemical signals compared to larvae raised at low densities, independent of density during adulthood. Our results demonstrate how inter-organismal signaling during development regulates reproductive maturation and longevity., Author summary The nematode C. elegans is one of the most highly developed models for the elucidation of conserved mechanisms connecting environmental cues to the regulation of animal lifespan and development. Surprisingly, the effects of larval population density on developmental timing and adult lifespan have not been investigated, although population density is known to affect developmental dynamics and survival in many species. We here describe a novel phenotype in C. elegans: population density-dependent acceleration of development. That high population density would accelerate development is unexpected, since at high population density accumulation of dauer pheromone, a developmental arrest signal, would be expected to slow down development. However, we found that C. elegans development is regulated by a pull-push mechanism, based on at least two different types of pheromone-like signals: the developmental acceleration signal we first describe in this manuscript, and its antagonist, the dauer pheromone, whose chemical make-up has gradually emerged over the past 10 years. We further show that both developmental acceleration and deceleration are mediated by two nuclear hormone receptors that have close mammalian homologs. Finally we demonstrate that larval population density predetermines adult lifespan in C. elegans hermaphrodites, including responses to hormonal stimuli during adulthood.

Coenzyme Q (CoQ, ubiquinone) is an essential component of the respiratory chain, a cofactor of pyrimidine biosynthesis and acts as an antioxidant in extra mitochondrial membranes. More recently CoQ has been identified as a modulator of apoptosis, inflammation and gene expression. CoQ deficient Caenorhabditis elegans clk-1 mutants show several phenotypes including a delayed postembryonic growth. Using wild type and two clk-1 mutants, here we established an experimental set-up to study the consequences of endogenous CoQ deficiency or exogenous CoQ supply on gene expression and growth. We found that a deficiency of endogenous CoQ synthesis down-regulates a cluster of genes that are important for growth (i.e., RNA polymerase II, eukaryotic initiation factor) and up-regulates oxidation reactions (i.e., cytochrome P450, superoxide dismutase) and protein interactions (i.e., F-Box proteins). Exogenous CoQ supply partially restores the expression of these genes as well as the growth retardation of CoQ deficient clk-1 mutants. On the other hand exogenous CoQ supply does not alter the expression of a further sub-set of genes. These genes are involved in metabolism (i.e., succinate dehydrogenase complex), cell signalling or synthesis of lectins. Thus, our work provides a comprehensive overview of genes which can be modulated in their expression by endogenous or exogenous CoQ. As growth retardation in CoQ deficiency is linked to the gene expression profile we suggest that CoQ promotes growth via gene expression.

lincRNAs recently have been discovered as evolutionary conserved transcripts of non-coding DNA sequences and have been implicated in the regulation of cellular differentiation. In humans, molecular studies have suggested a functional role for lincRNAs in cancer development. The aim of the present study was to examine whether these novel molecules are specifically regulated by different cytokines in cells of the innate immune system in humans in vivo and whether lincRNAs thereby might be involved in the pathophysiology of rheumatoid arthritis (RA). Therefore, CD 14(+) monocytes were isolated from RA patients before and after anti-IL-6R (tocilizumab) or anti-TNF-alpha (adalimumab) therapy and lincRNA transcription was analysed by a microarray based experiment. As expected, we found lincRNAs to be present in CD14(+) monocytes of RA patients. However, of the total number of 7.419 lincRNAs examined in this study only a very small number was significantly regulated by either IL-6 or TNF-alpha (85 lincRNAs, corresponding to 1.1%). The numbers of lincRNAs regulated was higher due to TNF-alpha compared to IL-6. Interestingly, none of the identified lincRNAs was influenced by both, IL-6 and TNF-alpha, suggesting the regulation of lincRNA transcription to be highly specific for distinct cytokines. Taken together, our results suggest (1) that lincRNAs are novel intracellular molecular effectors of specific cytokines in cells of the innate immune system in humans in vivo and (2) that lincRNAs might be involved in the molecular pathophysiology of RA. (C) 2014 Elsevier Ltd. All rights reserved.

Coenzyme Q derivatives (CoQ) are lipid soluble antioxidants that are synthesized endogenously in almost all species and function as an obligatory cofactor of the respiratory chain. There is evidence that CoQ status is altered by age in several species. Here we determined level and redox-state of CoQ in different age groups of pigs, mice and Caenorhabditis elegans. Since these species are very different with respect to lifespan, reproduction and physiology, our approach could provide some general tendencies of CoQ status in ageing organisms. We found that CoQ level decreases with age in pigs and mice, whereas CoQ content increases in older worms. As observed in all three species, ubiquinone, the oxidized form of CoQ, increases with age. Additionally, we were able to show that supplementation of ubiquinol-10, the reduced form of human CoQ(10), slightly increases lifespan of post-reproductive worms. In conclusion, the percentage of the oxidized form of CoQ increases with age indicating higher oxidative stress or rather a decreased anti-oxidative capacity of aged animals. (C) 2014 BioFactors

The metabolic and health-promoting effects of dietary restriction (DR) have been extensively studied in several species. The response to DR with respect to sex is essentially unknown. To address this question, we used the model organism Caenorhabditis elegans to analyze body composition and gene expression in males and hermaphrodites in response to DR. Unexpectedly, DR increased the fat-to-fat-free mass ratio and enlarged lipid droplets in both sexes to a similar extent. These effects were linked to a downregulation of the lipase-like 5 ( lipl-5) gene in both sexes at two developmental stages. By contrast, the reductions in body size, protein content, and total RNA content in response to DR were more pronounced in hermaphrodites than in males. Functional enrichment analysis of gene expression data showed a DR-induced downregulation of several embryogenesis-associated genes concomitant with an ongoing expression of sperm-associated genes in hermaphrodites. In conclusion, DR increases fat stores in both sexes of C. elegans in the form of large and possibly lipolysis-resistant lipid droplets and markedly alters the reproductive program in hermaphrodites but not in males.

Adjusting the efficiency of movement in response to environmental cues is an essential integrative characteristic of adaptive locomotion behavior across species. However, the modulatory molecules and the pathways involved are largely unknown. Recently, we demonstrated that in Caenorhabditis elegans, a loss-of-function of the two-pore-domain potassium (K2P) channel TWK-7 causes a fast, coordinated, and persistent forward crawling behavior in which five central aspects of stimulated locomotion—velocity, direction, wave parameters, duration, and straightness—are affected. Here, we isolated the reduction-of-function allele cau1 of the C. elegans gene kin-2 in a forward genetic screen and showed that it phenocopies the locomotor activity and locomotion behavior of twk-7(null) animals. Kin-2 encodes the negative regulatory subunit of protein kinase A (KIN-1/PKA). Consistently, we found that other gain-of-function mutants of the GαS-KIN-1/PKA pathway resemble kin-2(cau1) and twk-7(null) in locomotion phenotype. Using the powerful genetics of the C. elegans system in combination with cell type-specific approaches and detailed locomotion analyses, we identified TWK-7 as a putative downstream target of the GαS-KIN-1/PKA pathway at the level of the γ-aminobutyric acid (GABA)ergic D-type motor neurons. Due to this epistatic interaction, we suggest that KIN-1/PKA and TWK-7 may share a common pathway that is probably involved in the modulation of both locomotor activity and locomotion behavior during forward crawling.

Scope Epidemiological and experimental evidence indicates that maternal nutrition status contributes to long-term changes in the metabolic phenotype of the offspring, a process known as fetal programming. Methods and results We have used a swine model (Sus scrofa) to analyze consequences of a maternal low protein diet (about 50% of control) during pregnancy on hepatic lipid metabolism and genome-wide hepatic gene expression profile of juvenile female offspring (mean age 85 days). We found 318 S. scrofa genes to be differentially expressed in the liver at age 85 days. In the low protein offspring group key genes of fatty acid de novo synthesis were downregulated whereas several genes of lipolysis and phospholipid biosynthesis were upregulated. qRT-PCR analysis of selected genes verified microarray data and revealed linear correlations between gene expression levels and slaughter weight. Hepatic cholesterol 7α hydroxylase protein expression tended to be lower in the low protein group. Total lipid and triglyceride content and fatty acid composition of total lipids were not different between groups. Conclusion A maternal low protein diet during pregnancy induces a distinct hepatic gene expression signature in juvenile female pigs which was not translated into phenotypical changes of liver lipid metabolism.

Epidemiological data from human populations and few reports in rodents suggested that the paternal diet affects offspring adiposity and its related diseases. We tested whether this nongenetic and intergenerational inheritance depends on paternal treatment dose. Using the model organism Caenorhabditis elegans, males undergoing several dietary restriction regimes were crossed with ad libitum fed females. We found an inverted U-shaped relationship between the extent of paternal dietary restriction and the level of fat content of progeny. The relationship was evident in both sexes. Body proportions were not affected in offspring. Overall, our findings extent the concept of developmental and adaptive plasticity to include the extent of paternal food consumption in the origin of phenotypic alterations.

The apolipoprotein E (APOE) genotype is an important risk factor for ageing and age-related diseases. The APOE4 genotype (in contrast to APOE3) has been shown to be associated with oxidative stress and chronic inflammation. Metallothioneins (MT) exhibit antioxidant and anti-inflammatory activity, and MT overexpression has been shown to increase lifespan in mice. Interactions between APOE and MT, however, are largely unknown. Hence, we determined the effect of the APOE4 versus APOE3 genotype on MT levels in targeted gene replacement mice. APOE4 versus APOE3 mice exhibited significantly lower hepatic MT1 and MT2 mRNA as well as lower MT protein levels. The decrease in hepatic MT protein levels in APOE4 as compared to APOE3 mice was accompanied by lower nuclear Nrf1, a protein partly controlling MT gene expression. Cell culture experiments using hepatocytes identified allyl-isothiocyanate (AITC) as a potent MT inductor in vitro. Therefore, we supplemented APOE3 and APOE4 mice with AITC. However, AITC (15 mg/kg b.w.) could only partly correct for decreased MT1 and MT2 gene expression in APOE4 mice in vivo. Furthermore, cholesterol significantly decreased both Nrf1 and MT mRNA levels in Huh7 cells indicating that differences in MT gene expression between the two genotypes could be related to differences in hepatic cholesterol concentrations. Overall, present data suggest that the APOE genotype is an important determinant of tissue MT levels in mice and that MT gene expression may be impaired by the APOE4 genotype.

Coenzyme Q(10) is an essential cofactor in the respiratory chain and serves as a potent antioxidant in biological membranes. Recent studies in vitro and in vivo provide evidence that Coenzyme Q(10) is involved in inflammatory processes and lipid metabolism via gene expression. To study these effects at the epigenomic level, C57BL6J mice were supplemented for one week with reduced Coenzyme Q(10) (ubiquinol). Afterwards, gene expression signatures and DNA promoter methylation patterns of selected genes were analysed. Genome-wide transcript profiling in the liver identified 1112 up-regulated and 571 down-regulated transcripts as differentially regulated between ubiquinol-treated and control animals. Text mining and GeneOntology analysis revealed that the "top 20" ubiquinol-regulated genes play a role in lipid metabolism and are functionally connected by the PPARα signalling pathway. With regard to the ubiquinol-induced changes in gene expression of about +3.14-fold (p≤0.05), +2.18-fold (p≤0.01), and -2.13-fold (p≤0.05) for ABCA1, ACYP1, and ACSL1 genes, respectively, hepatic DNA methylation analysis of 282 (sense orientation) and 271 (antisense) CpG units in the respective promoter islands revealed no significant effect of ubiquinol. In conclusion, ubiquinol affects the expression of genes involved in PPARα signalling and lipid metabolism without changing the promoter DNA methylation status in the liver of mice.

In the present study the relationship between the CoQ10 redox state (% oxidized form of CoQ10 ) and the serum level of c-reactive protein (CRP) was investigated in a large Caucasian study population (n = 1319). In order to evaluate independently the influence of the variables that predict the outcome of CRP, an analysis of covariance (ANCOVA) was performed with CRP as the dependent variable. Gender was taken as an independent factor and CoQ10 redox and BMI as independent covariates. Results were substantiated with findings from a human intervention study (n = 53), receiving 150 mg/day ubiquinol for 14 days. Spearman's correlation revealed a significant (P 0.001) association between the CoQ10 redox state and CRP concentrations in the whole study population. Thus, higher CRP concentrations were found in subjects having more oxidized CoQ10 . Similar results were evident for further inflammatory markers (interleukin-6, number of leucocytes). The ANCOVA revealed a significant (P 0.001) prediction of CRP concentrations by CoQ10 redox state, after controlling for the effect of BMI and separately for gender. In the intervention study it was further found that the oral intake of ubiquinol increased its proportion significantly (P 0.001), with the highest increase in those persons having a low basal serum ubiquinol content (92.3%). Here it was discovered that the ubiquinol status significantly correlated to the concentration of the inflammation marker monocyte chemotactic protein 1. It is concluded that CoQ10 redox state predicts the concentration of CRP. Persons at risk with lower ubiquinol status, higher BMI, and low grade inflammation may benefit from ubiquinol supplementation. © 2016 BioFactors, 42(3):268-276, 2016.

Two-pore-domain K+ (K2P) channels are highly expressed in neurons and cardiac myocytes. In this study we investigated the potency of the antidepressant fluoxetine to inhibit brain and cardiac K2P channels, TREK-1, TASK-1 and THIK-1. Maximal sensitivity was detected for TREK-1, which was inhibited by 77% when expressed in HEK-293 cells and Xenopus oocytes. Alternative translation initiation (ATI) generates two different protein products from a single transcript of TREK-1. Electrophysiological analysis of two polypeptides engineered by mutagenesis (TREK-1[M53I], TREK-1[ΔN52]) revealed reduced current amplitude and K+ selectivity of the truncated TREK-1 isoform. The sensitivity of TREK-1[ΔN52] to fluoxetine decreased by 70%, indicating that the first 52 amino acids are essential for TREK-1 sensitivity to this drug.

Summary Seven isoforms of the multifunctional human Acyl-coenzyme A binding protein (ACBP) have been characterized so far. Through ab initio analysis of expressed sequence tag (ESTs), we identified a novel high-abundant ACBP splice variant ACBP1e encoding an ACBP isoform with a unique C-terminus of 81 amino acid residues. Bioinformatic analysis shows that this domain is evolutionary conserved and shares no significant homology with other known proteins, and its function is not known. Quantitative RT-polymerase chain reaction (PCR) revealed that ACBP1e is predominantly expressed in adipose tissue and hippocampus. Protein expression studies showed perinuclear clustering of ACBP1e. These clusters were not seen in ACBP1e mutants with an altered putative subtilisin/kexin isozyme-1 cleavage site within the C-terminus, indicating that this domain is required for proper localization of ACBP1e. Conclusively, we identified a novel ACBP isoforms with an unique C-terminal domain encoded by a high-abundant splice variant. 2011 IUBMB IUBMB Life, 63(7): 547–552, 2011

The proportions of body fat and fat-free mass are determining factors of adiposity-associated diseases. Work in Caenorhabditis elegans has revealed evolutionarily conserved pathways of fat metabolism. Nevertheless, analysis of body composition and fat distribution in the nematodes has only been partially unraveled because of methodological difficulties. We characterized metabolic C. elegans mutants by using novel and feasible BODIPY 493/503-based fat staining and flow cytometry approaches. Fixative as well as vital BODIPY staining procedures visualize major fat stores, preserve native lipid droplet morphology, and allow quantification of fat content per body volume of individual worms. Colocalization studies using coherent anti-Stokes Raman scattering microscopy, Raman microspectroscopy, and imaging of lysosome-related organelles as well as biochemical measurement confirm our approaches. We found that the fat-to-volume ratio of dietary restriction, TGF-β, and germline mutants are specific for each strain. In contrast, the proportion of fat-free mass is constant between the mutants, although their volumes differ by a factor of 3. Our approaches enable sensitive, accurate, and high-throughput assessment of adiposity in large C. elegans populations at a single-worm level.

An apoE4 genotype is an important risk factor for cardiovascular and other chronic diseases. The higher cardiovascular disease risk of apoE4 carriers as compared to the apoE3 genotype has been mainly attributed to the differences in blood lipids between the two genotype subgroups. Recently, a potential protective role of the transcription factor Nrf2 in cardiovascular disease prevention has been suggested. In this study, we show that Nrf2-dependent gene expression is affected by the apoE genotype. ApoE4 vs. apoE3 mice exhibited lower hepatic Nrf2 nuclear protein levels. Furthermore, mRNA and protein levels of Nrf2 target genes including glutathione-S-transferase, heme oxygenase-1 and NAD(P)H dehydrogenase, quinone 1 were significantly lower in apoE4 as compared to apoE3 mice. Lower hepatic mRNA levels of phase II enzymes, as observed in apoE4 vs. apoE3 mice, were accompanied by higher mRNA levels of phase I enzymes including Cyp26a1 and Cyp3a16. Furthermore, miRNA-144, miRNA-125b, and miRNA-29a involved in Nrf2 signaling, inflammation, and regulation of phase I enzyme gene expression were affected by the apoE genotype. We provide first evidence that Nrf2 is differentially regulated in response to the apoE genotype.

In the present study the effect of quercetin and its major metabolites quercetin-3-glucuronide (Q3G) and isorhamnetin on inflammatory gene expression was determined in murine RAW264.7 macrophages stimulated with lipopolysaccharide. Quercetin and isorhamnetin but not Q3G significantly decreased mRNA and protein levels of tumor necrosis factor alpha. Furthermore a significant decrease in mRNA levels of interleukin 1β, interleukin 6, macrophage inflammatory protein 1α and inducible nitric oxide synthase was evident in response to the quercetin treatment. However Q3G did not affect inflammatory gene expression. Anti-inflammatory properties of quercetin and isorhamnetin were accompanied by an increase in heme oxygenase 1 protein levels, a downstream target of the transcription factor Nrf2, known to antagonize chronic inflammation. Furthermore, proinflammatory microRNA-155 was down-regulated by quercetin and isorhamnetin but not by Q3G. Finally, anti-inflammatory properties of quercetin were confirmed in vivo in mice fed quercetin-enriched diets (0.1 mg quercetin/g diet) over 6 weeks.

Multiple genetic and environmental factors underlie the etiology of type 2 diabetes. To evaluate the influence of the relationship between dietary fat intake and single nucleotide polymorphisms (SNPs) in genes involved in fat assimilation on disease susceptibility, a 2-step approach using an exploratory case-control study (n = 192/384) and an independent, confirmatory case-cohort study (n = 614/2248) taken from the same prospective study population (European Prospective Investigation into Cancer and Nutrition-Potsdam) was used. Sixty-three SNPs in 32 genes were initially analyzed. Total intake of fat and fatty acid intake were calculated from validated baseline FFQ. The SNP × nutrient interaction was tested in multivariate adjusted regression models. The initial screening step revealed evidence that, for 4 SNPs (CAV2 rs2270188, DBI rs2084202, PPARG rs1801282, and SREBF1 rs2297508), disease susceptibility might depend on the amount and quality of fat intake. The insulin receptor regulator CAV2 rs2270188 G > T SNP was found to interact with dietary fat in the confirmatory case-cohort study. Using pooled data, homozygous individuals of the rare T-allele showed a 100% greater risk of type 2 diabetes if daily fat intake was increased from 30 to 40 % energy. An increase in dietary SFA from 10 to 20 % energy predicted an ~200% greater risk of type 2 diabetes. We found preliminary evidence that CAV2 rs2270188 interacts with dietary fat to affect risk of type 2 diabetes.

BACKGROUND The long-term role of fatty acids (FAs) in the cause of diabetes remains largely unclear. OBJECTIVE We aimed to investigate erythrocyte membrane FAs, desaturase activity, and dietary FAs in relation to the incidence of type 2 diabetes. DESIGN We applied a nested case-cohort design (n = 2724, including 673 incident diabetes cases) within the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam Study, which involves 27,548 middle-aged subjects. Thirty erythrocyte membrane FAs (percentage of total FAs) and FA intake (percentage of total fat) were measured at baseline, and physician-confirmed incident diabetes was assessed during a mean follow-up of 7.0 y. We evaluated Δ⁵ desaturase (D5D) and Δ⁶ desaturase (D6D) activity by using FA product-to-precursor ratios (traditional approach) and by investigating variants in FADS1 and FADS2 genes that encode these desaturases (Mendelian randomization approach). RESULTS As a main finding, erythrocyte 16:1n-7 and 18:3n-6 and FA ratios, which reflect stearoyl coenzyme A desaturase (SCD) and D6D activity, were directly related to diabetes risk in multivariable-adjusted models [relative risks (95% CIs) comparing extreme quintiles: 16:1n-7, 2.11 (1.46, 3.05); 18:3n-6, 2.00 (1.38, 2.88); SCD, 2.61 (1.75, 3.89); and D6D, 2.46 (1.67, 3.63)], whereas the FA ratio that reflects D5D activity was inversely associated with risk [0.46 (0.31, 0.70)]. The Mendelian randomization approach corroborated the direct relation for D6D activity and tended to support the inverse relation for D5D activity. Proportions of dietary FAs showed only modest to low correlations with erythrocyte FAs and were not significantly associated with risk. CONCLUSION The FA profile of erythrocyte membrane phospholipids and activity of desaturase enzymes are strongly linked to the incidence of type 2 diabetes.

Studies in humans and mice indicate a role for coenzyme Q10 (CoQ10) in gene expression. To analyze this function in relation to metabolism, SAMP1 mice were supplemented with the reduced (ubiquinol) or oxidized (ubiquinone) form of CoQ10 (500 mg/kg BW/d) for 14 months. Microarray analyses in liver tissues of SAMP1 mice identified 946 genes as differentially expressed between ubiquinol-treated and control animals (≥1.5-fold, P < 0.05). Text mining analyses revealed for a part of the ubiquinol-regulated genes, a functional connection in PPARα and LXR/RXR signalling pathways. Because these pathways are involved in cholesterol homeostasis, relevant metabolites were determined by gas chromatography/mass spectrometry (GC/MS). We found a significant increase of desmosterol (2.0-fold, P < 0.001) in the liver of ubiquinol-supplemented SAMP1 mice when related to control animals. In agreement, cholesterol concentrations were also distinctly increased (1.3-fold, P = 0.057). The Q10H2-induced PPARα and LXR/RXR gene expression signatures and effects on cholesterol metabolism were not apparent for the oxidized form of CoQ10. In conclusion, the reduced form of CoQ10 mediates distinct effects on cholesterol metabolism at the transcriptional and metabolite level in SAMP1 mice. © 2010 IUBMB IUBMB Life, 2010