Real-world characteristics and use patterns of patients treated with vericiguat: A nationwide longitudinal cohort study in Germany.

PURPOSE: Vericiguat reduced clinical endpoints in patients experiencing worsening heart failure in clinical trials, but its implementation outside trials is unclear. METHODS: This retrospective analysis of longitudinally collected data was based on the IQVIA™ LRx database, which includes ~ 80% of the prescriptions of the 73 million people covered by the German statutory health insurance. RESULTS: Between September 2021 and December 2022, vericiguat was initiated in 2916 adult patients. Their mean age was 73 ± 13 years and 28% were women. While approximately 70% were uptitrated beyond 2.5 mg, only 36% reached 10 mg. Median time to up-titration from 2.5 mg to 5 mg was 17 (quartiles: 11-33) days, and from 2.5 to 10 mg 37 (25-64) days, respectively. In 87% of the patients, adherence to vericiguat was high as indicated by a medication possession ratio of  ≥ 80%, and 67% of the patients persistently used vericiguat during the first year. Women and older patients reached the maximal dose of 10 mg vericiguat less often and received other substance classes of guideline-recommended therapy (GDMT) less frequently. The proportion of patients receiving four pillars of GDMT increased from 29% before vericiguat initiation to 44% afterwards. CONCLUSION: In a real-world setting, despite higher age than in clinical trials, adherence and persistence of vericiguat appeared satisfactory across age categories. Initiation of vericiguat was associated with intensification of concomitant GDMT. Nevertheless, barriers to vericiguat up-titration and implementation of other GDMT, applying in particular to women and elderly patients, need to be investigated further.

The Hyperpolarization-Activated HCN4 Channel is Important for Proper Maintenance of Oscillatory Activity in the Thalamocortical System.

Hyperpolarization-activated cation channels are involved, among other functions, in learning and memory, control of synaptic transmission and epileptogenesis. The importance of the HCN1 and HCN2 isoforms for brain function has been demonstrated, while the role of HCN4, the third major neuronal HCN subunit, is not known. Here we show that HCN4 is essential for oscillatory activity in the thalamocortical (TC) network. HCN4 is selectively expressed in various thalamic nuclei, excluding the thalamic reticular nucleus. HCN4-deficient TC neurons revealed a massive reduction of Ih and strongly reduced intrinsic burst firing, whereas the current was normal in cortical pyramidal neurons. In addition, evoked bursting in a thalamic slice preparation was strongly reduced in the mutant mice probes. HCN4-deficiency also significantly slowed down thalamic and cortical oscillations during active wakefulness. Taken together, these results establish that thalamic HCN4 channels are essential for the production of rhythmic intrathalamic oscillations and determine regular TC oscillatory activity during alert states.

HCN channels--modulators of cardiac and neuronal excitability.

Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels comprise a family of cation channels activated by hyperpolarized membrane potentials and stimulated by intracellular cyclic nucleotides. The four members of this family, HCN1-4, show distinct biophysical properties which are most evident in the kinetics of activation and deactivation, the sensitivity towards cyclic nucleotides and the modulation by tyrosine phosphorylation. The four isoforms are differentially expressed in various excitable tissues. This review will mainly focus on recent insights into the functional role of the channels apart from their classic role as pacemakers. The importance of HCN channels in the cardiac ventricle and ventricular hypertrophy will be discussed. In addition, their functional significance in the peripheral nervous system and nociception will be examined. The data, which are mainly derived from studies using transgenic mice, suggest that HCN channels contribute significantly to cellular excitability in these tissues. Remarkably, the impact of the channels is clearly more pronounced in pathophysiological states including ventricular hypertrophy as well as neural inflammation and neuropathy suggesting that HCN channels may constitute promising drug targets in the treatment of these conditions. This perspective as well as the current therapeutic use of HCN blockers will also be addressed.

Lab-scale tubular LED UV reactor for continuous photocatalysis.

Photocatalytic water treatment is considered a promising technique to prevent micropollutants from entering the environment. However, no off-the-shelf UV reactors on lab scale are available to study new processes and photocatalysts. In this study, we present a tubular UV reactor equipped with 30 UV-LEDs, emitting UV light at 367 nm and a total radiant flux of 42 W. The UV reactor has an irradiated length of 300 mm and can host any transparent chemical reactor on the inside with a maximum diameter of 28 mm. The device is optimized for lab experiments with total dimensions of just 334 mm x 193 mm x 172 mm. Besides water treatment, a broad range of other photochemical and photocatalytic experiments can be performed with the reactor. Two identical UV reactors have been built and are successfully used for photocatalytic water treatment experiments. The degradation of methylene blue with TiO2 as photocatalyst was studied to validate the UV reactor. Furthermore, photocatalytic and hybrid processes were conducted in the UV reactor to degrade a broad range of pharmaceutical micropollutants.

A follow-up study of a genome-wide association scan identifies a susceptibility locus for venous thrombosis on chromosome 6p24.1.

To identify genetic susceptibility factors conferring increased risk of venous thrombosis (VT), we conducted a multistage study, following results of a previously published GWAS that failed to detect loci for developing VT. Using a collection of 5862 cases with VT and 7112 healthy controls, we identified the HIVEP1 locus on chromosome 6p24.1 as a susceptibility locus for VT. Indeed, the HIVEP1 rs169713C allele was associated with an increased risk for VT, with an odds ratio of 1.20 (95% confidence interval 1.13-1.27, p = 2.86 x 10(-9)). HIVEP1 codes for a protein that participates in the transcriptional regulation of inflammatory target genes by binding specific DNA sequences in their promoter and enhancer regions. The current results provide the identification of a locus involved in VT susceptibility that lies outside the traditional coagulation/fibrinolysis pathway.

Distinct localization and modulation of Cav1.2 and Cav1.3 L-type Ca2+ channels in mouse sinoatrial node.

Dysregulation of L-type Ca(2+) currents in sinoatrial nodal (SAN) cells causes cardiac arrhythmia. Both Ca(v)1.2 and Ca(v)1.3 channels mediate sinoatrial L-type currents. Whether these channels exhibit differences in modulation and localization, which could affect their contribution to pacemaking, is unknown. In this study, we characterized voltage-dependent facilitation (VDF) and subcellular localization of Ca(v)1.2 and Ca(v)1.3 channels in mouse SAN cells and determined how these properties of Ca(v)1.3 affect sinoatrial pacemaking in a mathematical model. Whole cell Ba(2+) currents were recorded from SAN cells from mice carrying a point mutation that renders Ca(v)1.2 channels relatively insensitive to dihydropyridine antagonists. The Ca(v)1.2-mediated current was isolated in the presence of nimodipine (1 µm), which was subtracted from the total current to yield the Ca(v)1.3 component. With strong depolarizations (+80 mV), Ca(v)1.2 underwent significantly stronger inactivation than Ca(v)1.3. VDF of Ca(v)1.3 was evident during recovery from inactivation at a time when Ca(v)1.2 remained inactivated. By immunofluorescence, Ca(v)1.3 colocalized with ryanodine receptors in sarcomeric structures while Ca(v)1.2 was largely restricted to the delimiting plasma membrane. Ca(v)1.3 VDF enhanced recovery of pacemaker activity after pauses and positively regulated pacemaking during slow heart rate in a numerical model of mouse SAN automaticity, including preferential coupling of Ca(v)1.3 to ryanodine receptor-mediated Ca(2+) release. We conclude that strong VDF and colocalization with ryanodine receptors in mouse SAN cells are unique properties that may underlie a specific role for Ca(v)1.3 in opposing abnormal slowing of heart rate.

N-Hetaryl-[2(1H)-pyridinyliden]cyanamides: A New Class of Systemic Insecticides.

The new chemical class N-hetaryl-[2(1H)-pyridinylidene]cyanamides were inspired by the long known five-ring structure 2-chloro-5-[2-(nitro-methylene)-1-imidazolidinyl]-pyridine (Shell) and the current development candidate flupyrimin (Meiji Seika Pharma) via scaffold hopping and the concept for designing "shortened structures" by omitting the "methylene link" as a structural feature. The most active N-hetaryl-[2(1H)-pyridinylidene]cyanamides can be synthesized on a technical scale by a simple manufacturing procedure. As full nicotinic acetylcholine receptor (nAChR) agonists, the compounds bind with low affinity at the orthosteric binding site of nAChR. In molecular modeling studies, structural differences are visible in the superposition of active N-[6'-(trifluoromethyl)[1(2H),3'-bipyridin]-2-ylidene]cyanamide onto imidacloprid (IMD) and sulfoxaflor (SXF) in bound conformation. On the basis of their physicochemical properties, the most active xylem systemic candidates offer excellent aphicidal activity in vegetables and cotton, when applied as a foliar spray, by soil drench application, or, in particular, as seed dressing for seed treatment uses. Selected candidates show good plant compatibility and reveal a better risk profile with respect to bee pollinators than the majority of currently registered nAChR competitive modulators for seed treatment uses. Applied as a seed dressing in greenhouse profiling, good to excellent control of different aphid species has been observed. In field trials, an interesting level of activity potential against cereal grain aphids (inclusive virus vector control), corn rootworm, and wireworm could be demonstrated. According to molecular modeling investigations (Fukui functions, dipole moments, and electrostatic potentials), there is a broad scope for structure optimization of the chemical class leading to proposals for novel bicyclic insecticides.

Novel insights into the distribution of cardiac HCN channels: an expression study in the mouse heart.

HCN pacemaker channels (I(f) channels) are believed to contribute to important functions in the heart; thus these channels became an attractive target for generating transgenic mouse mutants to elucidate their role in physiological and pathophysiological cardiac conditions. A full understanding of cardiac I(f) and the interpretation of studies using HCN mouse mutants require detailed information about the expression profile of the individual HCN subunits. Here we investigate the cardiac expression pattern of the HCN isoforms at the mRNA as well as at the protein level. The specificity of antibodies used was strictly confirmed by the use of HCN1, HCN2 and HCN4 knockout animals. We find a low, but highly differential HCN expression profile outside the cardiac conduction pathway including left and right atria and ventricles. Additionally HCN distribution was investigated in tissue slices of the sinoatrial node, the atrioventricular node, the bundle of His and the bundle branches. The conduction system was marked by acetylcholine esterase staining. HCN4 was confirmed as the predominant isoform of the primary pacemaker followed by a distinct expression of HCN1. In contrast HCN2 shows only a confined expression to individual pacemaker cells. Immunolabeling of the AV-node reveals also a pronounced specificity for HCN1 and HCN4. Compared to the SN and AVN we found a low but selective expression of HCN4 as the only isoform in the atrioventricular bundle. However in the bundle branches HCN1, HCN4 and also HCN2 show a prominent and selective expression pattern. Our results display a characteristic distribution of individual HCN isoforms in several cardiac compartments and reveal that beside HCN4, HCN1 represents the isoform which is selectively expressed in most parts of the conduction system suggesting a substantial contribution of HCN1 to pacemaking.

HCN4 provides a 'depolarization reserve' and is not required for heart rate acceleration in mice.

Cardiac pacemaking involves a variety of ion channels, but their relative importance is controversial and remains to be determined. Hyperpolarization-activated, cyclic nucleotide-gated (HCN) channels, which underlie the I(f) current of sinoatrial cells, are thought to be key players in cardiac automaticity. In addition, the increase in heart rate following beta-adrenergic stimulation has been attributed to the cAMP-mediated enhancement of HCN channel activity. We have now studied mice in which the predominant sinoatrial HCN channel isoform HCN4 was deleted in a temporally controlled manner. Here, we show that deletion of HCN4 in adult mice eliminates most of sinoatrial I(f) and results in a cardiac arrhythmia characterized by recurrent sinus pauses. However, the mutants show no impairment in heart rate acceleration during sympathetic stimulation. Our results reveal that unexpectedly the channel does not play a role for the increase of the heart rate; however, HCN4 is necessary for maintaining a stable cardiac rhythm, especially during the transition from stimulated to basal cardiac states.

Discrepancy of particle passage in 101 mask batches during the first year of the Covid-19 pandemic in Germany.

During the first wave of Covid-19 infections in Germany in April 2020, clinics reported a shortage of filtering face masks with aerosol retention> 94% (FFP2 & 3, KN95, N95). Companies all over the world increased their production capacities, but quality control of once-certified materials and masks came up short. To help identify falsely labeled masks and ensure safe protection equipment, we tested 101 different batches of masks in 993 measurements with a self-made setup based on DIN standards. An aerosol generator provided a NaCl test aerosol which was applied to the mask. A laser aerosol spectrometer measured the aerosol concentration in a range from 90 to 500 nm to quantify the masks' retention. Of 101 tested mask batches, only 31 batches kept what their label promised. Especially in the initial phase of the pandemic in Germany, we observed fluctuating mask qualities. Many batches show very high variability in aerosol retention. In addition, by measuring with a laser aerosol spectrometer, we were able to show that not all masks filter small and large particles equally well. In this study we demonstrate how important internal and independent quality controls are, especially in times of need and shortage of personal protection equipment.

Molecular genetic analysis of a human insulin-like growth factor 1 promoter P1 variation.

Insulin-like growth factor 1 (IGF1) exerts important endocrine and paracrine functions in the cardiovascular system. We identified the common variant -1411C>T in the IGF1 upstream promoter P1, located within several overlapping transcription factor binding sites. Using transient transfection assays, we identified this site as a functional enhancer. The T allele-carrying enhancer, compared with the C allelic portion, exerts significantly reduced or even abrogated activity, respectively, in SaOs-2 and HepG2 (all P<0.0001) as well as in differentiated THP-1 macrophages. Electrophoretic mobility shift assay and subsequent supershift experiments in HepG2 identified c-Jun as the binding partner exclusively to the T allele, whereas CCAAT/enhancer-binding protein delta and interferon consensus site-binding protein/interferon-regulating factor 8 interacted only with the C allelic promoter portion. Furthermore, genotyping in a case-control study for essential hypertension (n=745 hypertensive patients; n=769 normotensive control subjects) for this variant revealed an odds ratio for hypertension of 0.73 (95% confidence interval 0.58-0.91, P=0.006) associated with the T allele, and normotensive subjects carrying the protective T allele displayed a significant decrease in diastolic (P=0.036) and systolic (P=0.024) blood pressure levels. We here report detection of a functional enhancer module in the upstream IGF1 promoter region, which might play a key role in local IGF1 bioavailability. Whether -1411C>T is also associated with other IGF1-related disease phenotypes should be evaluated further in population studies.

Identification and functional analyses of molecular haplotypes of the human osteoprotegerin gene promoter.

OBJECTIVE: Osteoprotegerin (OPG) has been reported to be involved in the development of atherosclerotic disease, and OPG gene variation has been associated with plasma OPG levels and different cardiovascular disease phenotypes. However, the genetic architecture of the OPG promoter and its transcriptional regulation are poorly characterized. METHODS AND RESULTS: We identified 1008 bp of the OPG 5'-flanking region to be sufficiently transcriptionally active in osteosarcoma cell lines and generated serial promoter deletion constructs. Individual subcloning revealed the existence of 3 molecular haplotypes (MolHaps): [T(-960)-A(-946)-G(-900)-T(-864); MolHap1, wild type], [T(-960)-G(-946)-G(-900)-T(-864); MolHap2], [C(-960)-G(-946)-A(-900)-G(-864); MolHap4]. Compared to MolHap1, transcriptional activities of MolHaps 2 and 4 were significantly reduced (P=0.0018). Whereas introduction of the -159C allele reduced transcriptional activities of the full-length constructs (P=0.0014), it significantly increased activities of the deletion constructs (P=0.0005). Electrophoretic mobility shift, competition, and chromatin immunoprecipitation assays revealed specific DNA:protein interactions for the MolHaps with Sp1 and NF-1, and identified Egr1 interacting exclusively with the -159T allele. CONCLUSIONS: We propose new structural and transcriptional features within the OPG promoter region and identified MolHaps being differentially transcriptionally active and allele-dependently interacting with a proximal polymorphic site.

Fast Detection of 2,4,6-Trinitrotoluene (TNT) at ppt Level by a Laser-Induced Immunofluorometric Biosensor.

The illegal use of explosives by terrorists and other criminals is an increasing issue in public spaces, such as airports, railway stations, highways, sports venues, theaters, and other large buildings. Security in these environments can be achieved by different means, including the installation of scanners and other analytical devices to detect ultra-small traces of explosives in a very short time-frame to be able to take action as early as possible to prevent the detonation of such devices. Unfortunately, an ideal explosive detection system still does not exist, which means that a compromise is needed in practice. Most detection devices lack the extreme analytical sensitivity, which is nevertheless necessary due to the low vapor pressure of nearly all explosives. In addition, the rate of false positives needs to be virtually zero, which is also very difficult to achieve. Here we present an immunosensor system based on kinetic competition, which is known to be very fast and may even overcome affinity limitation, which impairs the performance of many traditional competitive assays. This immunosensor consists of a monolithic glass column with a vast excess of immobilized hapten, which traps the fluorescently labeled antibody as long as no explosive is present. In the case of the explosive 2,4,6-trinitrotoluene (TNT), some binding sites of the antibody will be blocked, which leads to an immediate breakthrough of the labeled protein, detectable by highly sensitive laser-induced fluorescence with the help of a Peltier-cooled complementary metal-oxide-semiconductor (CMOS) camera. Liquid handling is performed with high-precision syringe pumps and chip-based mixing-devices and flow-cells. The system achieved limits of detection of 1 pM (1 ppt) of the fluorescent label and around 100 pM (20 ppt) of TNT. The total assay time is less than 8 min. A cross-reactivity test with 5000 pM solutions showed no signal by pentaerythritol tetranitrate (PETN), 1,3,5-trinitroperhydro-1,3,5-triazine (RDX), and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX). This immunosensor belongs to the most sensitive and fastest detectors for TNT with no significant cross-reactivity by non-related compounds. The consumption of the labeled antibody is surprisingly low: 1 mg of the reagent would be sufficient for more than one year of continuous biosensor operation.

Mouse models for studying pacemaker channel function and sinus node arrhythmia.

Pacemaker activity of the heart is generated by a small group of cells forming the sinoatrial node (SAN). Cells of the SAN are spontaneously active and generate action potentials with remarkable regularity and stability under all physiological conditions. The exact molecular mechanisms underlying pacemaker potentials in the SAN have not yet been fully elucidated. Several voltage-dependent ion channels as well as intracellular calcium cycling processes are thought to contribute to the pacemaker activity. Hyperpolarization-activated cation channels, which generate the I(f) current, have biophysical properties which seem ideally suited for the initiation of spontaneous electrical activity. This review describes recent work on several transgenic mice lacking different cardiac HCN channel subtypes. The role of I(f) for normal pacemaking and sinus node arrhythmia as revealed by these genetic models will be discussed. In addition, a new mouse line is described which enables gene targeting in a temporally-controlled manner selectively in SAN cells. Elucidating the function of HCN and other ion channels in well-controlled mouse models should ultimately lead to a better understanding of the mechanisms underlying human sinoatrial arrhythmias.

Tamoxifen-inducible gene deletion in the cardiac conduction system.

Temporally controlled gene deletion provides a powerful technique for examination of gene function in vivo. To permit use of this technology in the study of cardiac pacemaking, we attempted to generate a mouse line expressing an inducible Cre recombinase selectively in cardiac pacemaker cells. The tamoxifen-inducible CreER(T2) construct was 'knocked in' into the pacemaker channel HCN4 locus. In the absence of inducing agent, recombination was undetectable in HCN4-KiT mice. After injection of tamoxifen, highly selective and efficient recombination was observed in the sinoatrial and atrioventricular node. Expression of Cre and tamoxifen per se did not affect cardiac rhythm, basal heart rate and heart rate modulation. By crossing these animals with floxed HCN4 mice, complete deletion of this gene in the sinoatrial node could be achieved. HCN4-KiT mice represent the first tool for the temporally controlled inactivation of floxed target genes selectively in the conduction system of the murine heart.

SAH gene variants revisited in the European Project On Genes in Hypertension.

OBJECTIVE: Previous studies found significant association of hypertension and hypertension-related phenotypes with genetic variation in SAH (Spontaneously hypertensive rat-clone A-Hypertension-associated). We sought independent confirmation of these findings in the European Project On Genes in Hypertension. METHODS AND RESULTS: We randomly recruited 2603 relatives from 560 families and 31 unrelated subjects from six European populations (mean age 38.8 +/- 15.7 years; 52.1% women). We measured systolic/diastolic blood pressure (mean, 122.4/76.6 mmHg), body mass index (24.9 kg/m2), triceps skinfold (1.7 cm), waist-to-hip ratio (0.83 units), serum total and high-density lipoprotein (HDL) cholesterol (5.14 and 1.33 mmol/l), serum triglycerides (1.95 mmol/l) and blood glucose (4.90 mmol/l). We genotyped the G-1606A and -962del/ins polymorphisms. In all subjects, the allele frequencies were 11.8 and 29.5% for -1606A and -962del, respectively. Lewontin's D' was 0.97 (P < 0.0001). Haplotype frequencies were 58.8% for -1606G plus -962ins, 29.5% for -1606G plus -962del, and 11.7% for -1606A plus -962ins. Both before and after adjustment for covariates, none of the phenotype-genotype associations approached statistical significance. Our study had 80% power to detect on two-sided tests (P = 0.05), effect sizes of 1.8/1.3 mmHg for systolic/diastolic blood pressure, 0.52 kg/m2 for body mass index, 0.01 units for the waist-to-hip ratio, 0.96 mm for the triceps skinfold, 0.13 and 0.05 mmol/l for total and HDL cholesterol, 0.18 mmol/l for serum triglycerides, and 0.11 mmol/l for blood glucose. The family-based analyses did not reveal population stratification (P > or = 0.67). CONCLUSION: The evidence supporting an association of hypertension or hypertension-related phenotypes with the SAH gene remains equivocal in human studies.

Apolipoprotein E interrupts interleukin-1beta signaling in vascular smooth muscle cells.

OBJECTIVES: Apolipoprotein E (apoE) exerts antiatherogenic effects but precise mechanisms remain unclear. We here investigated the effect of apoE on intracellular signaling by interleukin-1beta (IL-1beta), a proinflammatory cytokine present in atherosclerotic lesions. METHODS AND RESULTS: IL-1beta-induced expression and activation of inducible nitric oxide synthase and cyclooxygenase-2 were inhibited by apoE in vascular smooth muscle cells (VSMCs). These inhibitory effects were linked to the suppression of both NF-kappaB and activating protein-1 (AP-1) transactivation, suggesting that the interruption of IL-1beta signaling occurs upstream of transcription factors. Studies in VSMCs overexpressing IL-1beta signaling intermediates revealed that NF-kappaB transactivation was inhibited by apoE in MyD88- and IRAK1- but not in TRAF6-transfected cells. Furthermore, apoE prevented IRAK1 phosphorylation and IRAK1-TRAF6 but not MyD88-IRAK1 complex formation. Inhibitory effects of apoE on IL-1beta signaling were abolished after silencing LDL receptor-related protein-1 (LRP1) expression with siRNA. In addition, inhibitors of adenylyl cyclase and protein kinase A (PKA) restored IL-1beta signaling in apoE-treated VSMCs, whereas apoE stimulated PKA activity. ApoE inhibited VSMC activation in response to IL-18 but not to tumor necrosis factor-alpha or polyinosinic:polycytidylic acid. CONCLUSION: ApoE targets IRAK-1 activation and thereby interrupts IL-1beta and IL-18 signaling in VSMCs. This antiinflammatory effect represents a novel antiatherogenic activity of apoE.

Polymorphisms in 33 inflammatory genes and risk of myocardial infarction--a system genetics approach.

The hypothesis of a causal link between inflammation and atherosclerosis would be strengthened if variants of inflammatory genes were associated with disease. Polymorphisms of 33 genes encoding inflammatory molecules were tested for association with myocardial infarction (MI). Patients with MI and a parental history of MI (n = 312) and controls from the UK (n = 317) were genotyped for 162 polymorphisms. Thirteen polymorphisms were associated with MI (P values ranging from 0.003 to 0.041). For three genes, ITGB1, SELP, and TNFRSF1B haplotype frequencies differed between patients and controls (P values < 0.01). We further assessed the simultaneous contribution of all polymorphisms and relevant covariates to MI using a two-step strategy of data mining relying on Random Forest and DICE algorithms. In a replication study involving two independent samples from the UK (n = 649) and France (n = 706), one interaction between the ITGA4/R898Q polymorphism and current smoking status was replicated. This study illustrates a strategy for assessing the joint effect of a large number of polymorphisms on a phenotype that may provide information that single locus or single gene analysis may fail to uncover. Overall, there was weak evidence for an implication of inflammatory polymorphisms on susceptibility to MI.

-391 C to G substitution in the regulator of G-protein signalling-2 promoter increases susceptibility to the metabolic syndrome in white European men: consistency between molecular and epidemiological studies.

BACKGROUND: The regulator of G-protein signalling-2 (RGS2) is a key factor in adipogenesis. We hypothesized that the metabolic syndrome, of which obesity is an important component, might be related to genetic variation in RGS2. METHODS AND RESULTS: We screened the human RGS2 gene. We tested the functionality of a common genetic variant in vitro, ex vivo, and in epidemiological study involving six European populations. The C to G substitution at position -391 in the RGS2 promoter was associated with enhanced RGS2 expression in vitro in transfected 3T3-L1 adipocytes and Chinese hamster cells and ex vivo in adipocytes from male, but not female, volunteers. In 2732 relatives from 512 families and 348 unrelated individuals, randomly recruited from six European populations, the prevalence of GG homozygosity was 54.1%. The metabolic syndrome score, a composite of six continuous traits making up this clinical entity, was 0.27 standardized units higher (P < 0.001) in 795 GG homozygous men compared with 683 men carrying the C allele. Transmission of the -391 G allele to male offspring was associated with a 0.20 unit increase in the score (P=0.039). These epidemiological relations were not significant in 1602 women. CONCLUSIONS: The C to G substitution at position -391 in the RGS2 promoter increases RGS2 expression in adipocytes and is associated with the metabolic syndrome in white European men. Further experimental and clinical research should establish whether this common polymorphism might be a target for preventive or therapeutic intervention.

SAH gene variants are associated with obesity-related hypertension in Caucasians: the PEGASE Study.

OBJECTIVE: The SAH gene locus has recently been proposed to be involved in obesity-related hypertension in Japanese individuals. METHODS: To replicate independently the initial findings in another ethnic group, we scanned the entire SAH gene in 190 Caucasian chromosomes. A total of 651 patients with essential hypertension and 776 controls (PEGASE Study) were genotyped for all identified variants using allele-specific oligonucleotides, and single nucleotide polymorphism as well as haplotype analyses were carried out. We also performed transient transfection experiments, northern and western blots, immunoprecipitation, and acyl-coenzyme A synthetase activity assays. RESULTS: We identified five polymorphisms in the promoter region (C-1808T, G-1606A, -962ins/del, G-451A, T-67C), two in introns 5 and 7 (T+9/In5C, A+20/In7T), and one missense variant (K359N). Carriage of the -1606A allele was significantly associated with hypertension [odds ratio (OR) 1.28, P = 0.049] as was 359N (OR 1.35, P = 0.048) compared with non-carriers. Conversely, for -962del, the OR for hypertension was 0.80 (P = 0.042). The SAH alleles -1606A and 359N, but not -962ins/del, displayed a raising effect on body mass index (BMI; P = 0.004 and P = 0.030, respectively) in hypertensive as well as in control individuals. After adjustment for BMI in hypertensive individuals, only the OR associated with -962ins/del remained significant (OR 0.77, P = 0.028). Functional analyses in BHK did not reveal differences for SAH 359N or 359K-containing constructs, formally excluding K359N as the functional variant. CONCLUSION: We confirm recent evidence that the SAH locus is associated with obesity-related hypertension, in which pathophysiological context SAH variants affecting blood pressure remain, however, to be shown.