Towards a more effective reach legislation in protecting human health more effective reach in protecting human health

There is growing evidence indicating the substantial contribution of man-made products to an increase in the risk of diseases of civilization. In this article, the Belgian Scientific Registration, Evaluation, Authorization and restriction of CHemicals (REACH) Committee gives a critical view on the working of REACH. The current regulatory framework needs to further evolve taking into account data generated using modern science and technology. There is a need for improved assessment process not only before but also after entering the market. Objectivity, transparency, and the follow-up after market access can be optimized. Additionally, no guidance documents exist for regulation of mixture effects. Further, the lengthiness before regulatory action is a big concern. Decision making often takes several years leading to uncertainties for both producers and end users. A first proposed improvement is the implementation of independent toxicity testing, to assure objectivity, transparency, and check and improve compliance. A "no data, no market" principle could prevent access of hazardous chemicals to the market. Additionally, the introduction of novel testing could improve information on endpoints such as endocrine disrupting abilities, neurotoxicity, and immunotoxicity. An adapted regulatory framework that integrates data from different sources and comparing the outputs with estimates of exposure is required. Fast toxicology battery testing and toxicokinetic testing could improve speed of decision making. Hereby, several improvements have been proposed that could improve the current REACH legislation.

What is in the fish? Collaborative trial in suspect and non-target screening of organic micropollutants using LC- and GC-HRMS

A collaborative trial involving 16 participants from nine European countries was conducted within the NORMAN network in efforts to harmonise suspect and non-target screening of environmental contaminants in whole fish samples of bream (Abramis brama). Participants were provided with freeze-dried, homogenised fish samples from a contaminated and a reference site, extracts (spiked and non-spiked) and reference sample preparation protocols for liquid chromatography (LC) and gas chromatography (GC) coupled to high resolution mass spectrometry (HRMS). Participants extracted fish samples using their in-house sample preparation method and/or the protocol provided. Participants correctly identified 9-69 % of spiked compounds using LC-HRMS and 20-60 % of spiked compounds using GC-HRMS. From the contaminated site, suspect screening with participants' own suspect lists led to putative identification of on average ∼145 and ∼20 unique features per participant using LC-HRMS and GC-HRMS, respectively, while non-target screening identified on average ∼42 and ∼56 unique features per participant using LC-HRMS and GC-HRMS, respectively. Within the same sub-group of sample preparation method, only a few features were identified by at least two participants in suspect screening (16 features using LC-HRMS, 0 features using GC-HRMS) and non-target screening (0 features using LC-HRMS, 2 features using GC-HRMS). The compounds identified had log octanol/water partition coefficient (KOW) values from -9.9 to 16 and mass-to-charge ratios (m/z) of 68 to 761 (LC-HRMS and GC-HRMS). A significant linear trend was found between log KOW and m/z for the GC-HRMS data. Overall, these findings indicate that differences in screening results are mainly due to the data analysis workflows used by different participants. Further work is needed to harmonise the results obtained when applying suspect and non-target screening approaches to environmental biota samples.

Effects of adding high- vs low-intensity resistance training to endurance training in patients with heart failure: preliminary results of a randomized controlled trial

Background

In current ESC/EAPC guidelines, adding resistance training to endurance training is advised for patients with heart failure (HF), but the optimal intensity of the resistance training is unknown (40–80% of 1RM is advised).

Purpose

To investigate the effects of high- vs low-intensity resistance training as an adjunct to endurance training on: aerobic capacity (primary outcome), walking capacity, muscle strength and quality of life in patients with HF.

Methods

Forty patients with HF were consecutively recruited in the cardiac rehabilitation center of the Hospital East-Limburg in Belgium. Patients were block-randomized (by age and sex) by an independent researcher to receive maximally 45 supervised sessions (3x/week) of high-intense (HI: 3 exercises, 3x12 repetitions, 55–70%1RM) or low-intense resistance training (LI: 3 exercises, 3x22 repetitions, 35–40%1RM) as an adjunct to endurance training (30 min/session; 50–75% VO2max). The aerobic capacity (VO2max) was measured by a blinded assessor with a ramp cardiopulmonary cycling test (+5–30W/min). Walking distance was assessed with a 6-minute walk test (6MWT), maximal strength with 1RM (leg-press, pull-down and dip), and quality of life with the Minnesota questionnaire. An unpaired t-test, Mann-Whitney U test or ANCOVA were used for between-group analysis, and paired t-test or Wilcox sign-rank test for the within-group analysis.

Results

Both groups had similar baseline characteristics and training adherence (HI vs LI; 20 vs 20 subjects; Age: 62±9 vs 59±13 years; Sex: 76% vs 79%male; BMI: 27±58 vs 29±4 kg/m2; LVEF: 35±10 vs 38±6%; Adherence: 33±10 vs 36±10 sessions; p>0.05). There were no adverse events. Both groups had significant within-group improvements in aerobic and walking capacity (VO2max: LI (n=20) vs HI (n=19), p≤0.010; 6MWT distance: p≤0.007) (Figure 1), but these improvements did not differ between groups (VO2max: p=0.855; 6MWT distance: p=0.854). The LI group improved significantly more in muscle strength than the HI group (dip and leg-press: p<0.001). Although the LI group significantly improved in the quality of life (Minnesota score reduction: p=0.028), the quality of life did not differ between groups (Minnesota score: p=0.756).

Conclusions

Both low-and high-intense resistance training are similarly beneficial for improving aerobic and walking capacity in patients with HF. Surprisingly, low-intense resistance training seems superior to high-intense training in improving muscle strength.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Hasselt University

Concurrent Assessment of Phthalates/HEXAMOLL® DINCH Exposure and Wechsler Intelligence Scale for Children Performance in Three European Cohorts of the HBM4EU Aligned Studies

Information about the effects of phthalates and non-phthalate substitute cyclohexane-1,2-dicarboxylic acid diisononyl ester (HEXAMOLL^® DINCH) on children's neurodevelopment is limited. The aim of the present research is to evaluate the association between phthalate/HEXAMOLL^® DINCH exposure and child neurodevelopment in three European cohorts involved in HBM4EU Aligned Studies. Participating subjects were school-aged children belonging to the Northern Adriatic cohort II (NAC-II), Italy, Odense Child Cohort (OCC), Denmark, and PCB cohort, Slovakia. In each cohort, children's neurodevelopment was assessed through the Full-Scale Intelligence Quotient score (FSIQ) of the Wechsler Intelligence Scale of Children test using three different editions. The children's urine samples, collected for one point in time concurrently with the neurodevelopmental evaluation, were analyzed for several phthalates/HEXAMOLL^® DINCH biomarkers. The relation between phthalates/HEXAMOLL^® DINCH and FSIQ was explored by applying separate multiple linear regressions in each cohort. The means and standard deviations of FSIQ were 109 ± 11 (NAC-II), 98 ± 12 (OCC), and 81 ± 15 (PCB cohort). In NAC-II, direct associations between FSIQ and DEHP's biomarkers were found: 5OH-MEHP+5oxo-MEHP (β = 2.56; 95% CI 0.58-4.55; N = 270), 5OH-MEHP+5cx-MEPP (β = 2.48; 95% CI 0.47-4.49; N = 270) and 5OH-MEHP (β = 2.58; 95% CI 0.65-4.51; N = 270). On the contrary, in the OCC the relation between DEHP's biomarkers and FSIQ tended to be inverse but imprecise (p-value ≥ 0.10). No associations were found in the PCB cohort. FSIQ was not associated with HEXAMOLL^® DINCH in any cohort. In conclusion, these results do not provide evidence of an association between concurrent phthalate/DINCHHEXAMOLLR DINCH exposure and IQ in children.

Cardiac electrophysiology studies in mice via the transjugular route: a comprehensive practical guide

Cardiac arrhythmias are associated with cardiovascular morbidity and mortality. Cardiac electrophysiology studies (EPS) use intracardiac catheter recording and stimulation for profound evaluation of the heart's electrical properties. The main clinical application is investigation and treatment of rhythm disorders. These techniques have been translated to the murine setting to open opportunities for detailed evaluation of the impact of different characteristics (including genetics) and interventions on cardiac electrophysiology and -pathology. Currently, a detailed description of the technique of murine transjugular EPS (which is the standard route of catheter introduction) is lacking. This article provides detailed information on EPS in mice via the transjugular route. This includes catheter placement, stimulation protocols, intracardiac tracing interpretation, artefact reduction and surface ECG recording. In addition, reference values as obtained in C57BL/6N mice are presented for common electrophysiological parameters. This detailed methodological description aims to increase accessibility and standardisation of EPS in mice. Ultimately, also human research and patient care may benefit from translation of the knowledge obtained in preclinical models using this technique.

TRPM4 inhibition by meclofenamate suppresses Ca2+-dependent triggered arrhythmias

AIMS

Cardiac arrhythmias are a major factor in the occurrence of morbidity and sudden death in patients with cardiovascular disease. Disturbances of Ca2+ homeostasis in the heart contribute to the initiation and maintenance of cardiac arrhythmias. Extrasystolic increases in intracellular Ca2+ lead to delayed afterdepolarizations and triggered activity, which can result in heart rhythm abnormalities. It is being suggested that the Ca2+-activated nonselective cation channel TRPM4 is involved in the aetiology of triggered activity, but the exact contribution and in vivo significance are still unclear.

METHODS AND RESULTS

In vitro electrophysiological and calcium imaging technique as well as in vivo intracardiac and telemetric electrocardiogram measurements in physiological and pathophysiological conditions were performed. In two distinct Ca2+-dependent proarrhythmic models, freely moving Trpm4-/- mice displayed a reduced burden of cardiac arrhythmias. Looking further into the specific contribution of TRPM4 to the cellular mechanism of arrhythmias, TRPM4 was found to contribute to a long-lasting Ca2+ overload-induced background current, thereby regulating cell excitability in Ca2+ overload conditions. To expand these results, a compound screening revealed meclofenamate as a potent antagonist of TRPM4. In line with the findings from Trpm4-/- mice, 10 µM meclofenamate inhibited the Ca2+ overload-induced background current in ventricular cardiomyocytes and 15 mg/kg meclofenamate suppressed catecholaminergic polymorphic ventricular tachycardia-associated arrhythmias in a TRPM4-dependent manner.

CONCLUSION

The presented data establish that TRPM4 represents a novel target in the prevention and treatment of Ca2+-dependent triggered arrhythmias.

Effects of the addition of high- vs. low-intensity resistance training on top of endurance training in patients with heart failure: preliminary results from a randomized clinical trial

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): Hasselt University

Background

Adding resistance training on top of endurance training is recommended in the rehabilitation of patients with heart failure. However, it is unknown which intensity of resistance training should be preferred.

Purpose

To compare the effects of the addition of high- vs. low-intensity resistance training on top of endurance training in patients with heart failure.

Methods

Nineteen patients with heart failure were block randomized (by gender and sex) in a combined high-intensity resistance and endurance group (HIG; n=8, age=61±12y, 7 males, LVEF=38±10%) vs. combined low-intensity resistance and endurance group (LIG; n=9, age=68±21y, 8 males, LVEF=38±13%). Patients trained 3x/week for 45 sessions. The resistance exercises were volume-matched between groups and consisted of three sets of leg press, pull down and dip exercises, separated by 30s of rest, done at 55-70% 1RM in HIG vs. 35-40% 1RM in LIG. Both groups did moderate-intense endurance training on a bicycle, cross-trainer, treadmill and arm ergometer for 30 min per training. Maximal oxygen consumption was evaluated with an incremental cardiopulmonary cycling test and muscle strength by 1-RM testing, while quality of life was assessed with the Minnesota questionnaire, and walking distance by a 6-minute walking test. Mann-Whitney U test was used for analyzing differences between groups in all variables and Wilcoxon signed-rank test for evaluating pre-post difference of the entire sample. P values <0,05 (2-tailed) were considered statistically significant.

Results

Training adherence was similar in both groups (LIG vs HIG: 41±6 vs 37±9 sessions, p=0,370; Table 1). Overall, the intervention improved maximal oxygen consumption, walking capacity and muscle strength (p<0,05), but the between-group changes in maximal oxygen consumption (LIG vs HIG: 3±2 vs 3±4 ml/kg/min, p=0,963), quality of life (LIG vs HIG: -8±23 vs -1±5 points, p=0,931) and muscle strength (LIG vs HIG: Dip 34±34 vs 18±20kg, p=0,481; Leg press, 66±87 vs 47±53kg, p=0,486; Pull down, 9±6 vs 9±7kg, p=0,574) were similar.

Conclusion

Adding either high- or low-intensity resistance training on top of endurance training seems equally effective for improving aerobic capacity and walking performance in patients with heart failure. The study is ongoing.

Internal exposure of Flemish teenagers to environmental pollutants: Results of the Flemish Environment and Health Study 2016-2020 (FLEHS IV)

The Flemish Environment and Health Study (FLEHS) collects information on internal exposure to a broad range of environmental chemicals in the general population in Flanders, the Northern region of Belgium. The aim is to establish biomonitoring exposure distributions for the general population in support of public health and environmental policy, environmental risk assessment and risk management decisions. In 2017-2018, urine and blood samples were collected from 428 teenagers by a stratified clustered two stage randomized design. Samples were analyzed for a broad range of biomarkers related to exposure to chlorinated and newer pesticides, brominated and organophosphate flame retardants (BFR/OPFR), polychlorinated biphenyls (PCBs), bisphenols, phthalates and alternative plasticizers, per-and polyfluoroalkyl substances (PFAS), polycyclic aromatic hydrocarbons (PAHs), benzene, metals and trace elements. The geometric mean levels and percentiles of the distribution were estimated for each biomarker, for the whole study population and following stratification for sex, the household educational attainment and the residence area's urbanicity. Geometric means of biomarkers of lead, dichlorodiphenyltrichloroethane (DDT), PCBs, PAHs, regulated phthalates and bisphenol A (BPA) were lower than in the previous FLEHS cycles. Most biomarker levels were below health-based guidance values (HB-GVs). However, HB-GVs of urinary arsenic, blood lead, blood cadmium, sum of serum perfluorooctane sulfonate (PFOS) and perfluoro-1-hexanesulfonate (PFHxS) and the urinary pyrethroid metabolite (3-PBA) were exceeded in respectively 25%, 12%, 39.5%, 10% and 22% of the teenagers. These results suggest that the levels of exposure in the Flemish population to some environmental chemicals might be of concern. At the same time, we noticed that biomarkers for BPA substitutes, metabolites of OPFRs, an expanded list of PFAS, glyphosate and its metabolite could be measured in substantial proportions of participants. Interpretation of these levels in a health-risk context remains uncertain as HB-GVs are lacking. Household educational attainment and residential urbanicity were significant exposure determinants for many biomarkers and could influence specific biomarker levels up to 70% as shown by multiple regression analysis. The research consortium also took care of the broader external communication of results with participants, policy makers, professional groups and civil society organizations. Our study demonstrated that teenagers are exposed to a wide range of chemicals, it demonstrates the success of public policies to reduce exposure but also points to concern and further priorities and needs for follow up.

[Chaplaincy care in psychotrauma care: an exploration]

BACKGROUND

The care for people with trauma- and stressor-related disorders is multidisciplinary. The place of chaplaincy care in multidisciplinary trauma care has received limited attention.

AIM

Exploration of the place of chaplaincy care in relation to psychotrauma, moral injury, grief and palliative care and in time in relation to exposure to psychotrauma as a basis for a model of multidisciplinary collaboration.

METHOD

Inventory and discussion of the position of chaplaincy care in the literature and guidelines for trauma- and stressor-related disorders.

RESULTS

Chaplaincy care may support finding meaning and reconnection in people at risk of trauma and PTSD, moral injury, and traumatic grief. Chaplaincy care is increasingly available for palliative and multicultural care recipients. Most guidelines for trauma care recommend the availability of chaplaincy care or research into the effectiveness of complementary existential, spiritual or meaning-making interventions.

CONCLUSION

Traumatic stressors represent limit experiences, whereby the quest for meaning, existential and moral orientation are pre-eminently at stake. The use of chaplaincy care supports finding meaning and reconnection and may thereby potentially contribute to the prevention of traumatic exposure to stressors, persistent symptoms after exposure, and worsening of chronic trauma- and stressor related symptoms.

Neuregulin-1 compensates for endothelial nitric oxide synthase deficiency

Endothelial cells (ECs) secrete different paracrine signals that modulate the function of adjacent cells; two examples of these paracrine signals are nitric oxide (NO) and neuregulin-1 (NRG1), a cardioprotective growth factor. Currently, it is undetermined whether one paracrine factor can compensate for the loss of another. Herein, we hypothesized that NRG1 can compensate for endothelial NO synthase (eNOS) deficiency. We characterized eNOS null and wild-type (WT) mice by cardiac ultrasound and histology and we determined circulating NRG1 levels. In a separate experiment, eight groups of mice were divided into four groups of eNOS null mice and WT mice; half of the mice received angiotensin II (ANG II) to induce a more severe phenotype. Mice were randomized to daily injections with NRG1 or vehicle for 28 days. eNOS deficiency increased NRG1 plasma levels, indicating that ECs increase their NRG1 expression when NO production is deleted. eNOS deficiency also increased blood pressure, lowered heart rate, induced cardiac fibrosis, and affected diastolic function. In eNOS null mice, ANG II administration not only increased cardiac fibrosis but also induced cardiac hypertrophy and renal fibrosis. NRG1 administration prevented cardiac and renal hypertrophy and fibrosis caused by ANG II infusion and eNOS deficiency. Moreover, Nrg1 expression in the myocardium is shown to be regulated by miR-134. This study indicates that administration of endothelium-derived NRG1 can compensate for eNOS deficiency in the heart and kidneys.NEW & NOTEWORTHY ECs compensate for eNOS deficiency by increasing the secretion of NRG1. NRG1 administration prevents cardiac and renal hypertrophy and fibrosis caused by ANG II infusion and eNOS deficiency. NRG1 expression is regulated by miR-134.

Doxorubicin induces arterial stiffness: A comprehensive in vivo and ex vivo evaluation of vascular toxicity in mice

Arterial stiffness is an important predictor of cardiovascular risk. Clinical studies have demonstrated that arterial stiffness increases in cancer patients treated with the chemotherapeutic doxorubicin (DOX). However, the mechanisms of DOX-induced arterial stiffness remain largely unknown. This study aimed to evaluate artery stiffening in DOX-treated mice using in vivo and ex vivo techniques. Male C57BL/6J mice were treated for 2 weeks with 2 mg/kg (low dose) or 4 mg/kg (high dose) of DOX weekly. Arterial stiffness was assessed in vivo with ultrasound imaging (abdominal aorta pulse wave velocity (aaPWV)) and applanation tonometry (carotid-femoral PWV) combined with ex vivo vascular stiffness and reactivity evaluation. The high dose increased aaPWV, while cfPWV did not reach statistical significance. Phenylephrine (PE)-contracted aortic segments showed a higher Peterson's modulus (Ep) in the high dose group, while Ep did not differ when vascular smooth muscle cells (VSMCs) were relaxed by a NO donor (DEANO). In addition, aortic rings of DOX-treated mice showed increased PE contraction, decreased basal nitric oxide (NO) index and impaired acetylcholine-induced endothelium-dependent relaxation. DOX treatment contributed to endothelial cell loss and reduced endothelial nitric oxide synthase (eNOS) expression in the aorta. In conclusion, we have replicated DOX-induced arterial stiffness in a murine model and this aortic stiffness is driven by impaired endothelial function, contributing to increased vascular tone.

Predictive performance of parent-metabolite population pharmacokinetic models of (S)-ketamine in healthy volunteers

Purpose

The recent repurposing of ketamine as treatment for pain and depression has increased the need for accurate population pharmacokinetic (PK) models to inform the design of new clinical trials. Therefore, the objectives of this study were to externally validate available PK models on (S)-(nor)ketamine concentrations with in-house data and to improve the best performing model when necessary.

Methods

Based on predefined criteria, five models were selected from literature. Data of two previously performed clinical trials on (S)-ketamine administration in healthy volunteers were available for validation. The predictive performances of the selected models were compared through visual predictive checks (VPCs) and calculation of the (root) mean (square) prediction errors (ME and RMSE). The available data was used to adapt the best performing model through alterations to the model structure and re-estimation of inter-individual variability (IIV).

Results

The model developed by Fanta et al. (Eur J Clin Pharmacol 71:441–447, 2015) performed best at predicting the (S)-ketamine concentration over time, but failed to capture the (S)-norketamine C_max correctly. Other models with similar population demographics and study designs had estimated relatively small distribution volumes of (S)-ketamine and thus overpredicted concentrations after start of infusion, most likely due to the influence of circulatory dynamics and sampling methodology. Model predictions were improved through a reduction in complexity of the (S)-(nor)ketamine model and re-estimation of IIV.

Conclusion

The modified model resulted in accurate predictions of both (S)-ketamine and (S)-norketamine and thereby provides a solid foundation for future simulation studies of (S)-(nor)ketamine PK in healthy volunteers after (S)-ketamine infusion.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00228-021-03104-1.

Changes in DNA Methylation in Arabidopsis thaliana Plants Exposed Over Multiple Generations to Gamma Radiation

Previous studies have found indications that exposure to ionising radiation (IR) results in DNA methylation changes in plants. However, this phenomenon is yet to be studied across multiple generations. Furthermore, the exact role of these changes in the IR-induced plant response is still far from understood. Here, we study the effect of gamma radiation on DNA methylation and its effect across generations in young Arabidopsis plants. A multigenerational set-up was used in which three generations (Parent, generation 1, and generation 2) of 7-day old Arabidopsis thaliana plants were exposed to either of the different radiation treatments (30, 60, 110, or 430 mGy/h) or to natural background radiation (control condition) for 14 days. The parental generation consisted of previously non-exposed plants, whereas generation 1 and generation 2 plants had already received a similar irradiation in the previous one or two generations, respectively. Directly after exposure the entire methylomes were analysed with UPLC-MS/MS to measure whole genome methylation levels. Whole genome bisulfite sequencing was used to identify differentially methylated regions (DMRs), including their methylation context in the three generations and this for three different radiation conditions (control, 30 mGy/h, and 110 mGy/h). Both intra- and intergenerational comparisons of the genes and transposable elements associated with the DMRs were made. Taking the methylation context into account, the highest number of changes were found for cytosines followed directly by guanine (CG methylation), whereas only limited changes in CHG methylation occurred and no changes in CHH methylation were observed. A clear increase in IR-induced DMRs was seen over the three generations that were exposed to the lowest dose rate, where generation 2 had a markedly higher number of DMRs than the previous two generations (Parent and generation 1). Counterintuitively, we did not see significant differences in the plants exposed to the highest dose rate. A large number of DMRs associated with transposable elements were found, the majority of them being hypermethylated, likely leading to more genetic stability. Next to that, a significant number of DMRs were associated with genes (either in their promoter-associated region or gene body). A functional analysis of these genes showed an enrichment for genes related to development as well as various stress responses, including DNA repair, RNA splicing, and (a)biotic stress responses. These observations indicate a role of DNA methylation in the regulation of these genes in response to IR exposure and shows a possible role for epigenetics in plant adaptation to IR over multiple generations.

P4995Neuregulin-1 compensates for endothelial NO synthase deficiency in the heart and kidney

Background

Decreased eNOS activity is the hallmark of endothelial dysfunction and is associated with cardiovascular and renal disorders. Besides NO, endothelial cells produce numerous other small molecules, peptides, and proteins, which modulate the function of adjacent cells. For instance, neuregulin-1 (NRG-1) is an endothelium-derived growth factor, which plays crucial roles in cardiovascular development, has cardioprotective properties, and induces growth and differentiation of cell types in different organs, including the kidney.

Purpose

Although the cardioprotective effects of endothelium-derived NO and NRG-1 are well established, their interaction is not clear. Therefore, we studied the interaction between the NO/eNOS and NRG-1/ErbB signalling pathways in a transgenic eNOS knock-out mouse model (eNOS−/−) treated with subpressor doses of angiotensin II (AngII).

Methods

eNOS−/− mice and their wild type (WT) littermates (n=64, 15 weeks old) were randomized for implantation of osmotic minipumps with AngII (400 ng/kg.min) for 28 days or sham surgery. Mice were randomized to receive either daily NRG-1 injections (20 μg/kg, intraperitoneal) or vehicle for 4 weeks (n=8/group). Hypertrophy and fibrosis were measured in left ventricle (LV) and kidneys using echography and immunohistochemical staining.

Results

Although blood pressure was higher in eNOS−/− mice compared to their WT littermates, it was unaffected by a subpressor dose of AngII. Masson's trichrome staining showed that AngII significantly increased LV (interstitial and perivascular) and renal fibrosis in eNOS−/− mice, but not in WT controls (see figure for LV data). NRG-1 reversed this AngII-induced LV and renal fibrosis caused by eNOS deficiency. There was also significant hypertrophy of LV and kidneys in eNOS−/− mice treated with AngII, which was again normalized by NRG-1 treatment. Moreover, NRG-1 significantly attenuated albuminuria induced by eNOS deficiency under AngII treatment.

Conclusions

This study demonstrates that the anti-fibrotic and anti-hypertrophic effects of NRG-1 are independent from the NO/eNOS pathway in both heart and kidney. Strikingly, NRG-1 is able to compensate for some of the negative effects of eNOS deficiency, at least in conditions of AngII stimulation.

Acknowledgement/Funding

supported by university of Antwerp

Abstract 506: Trpm4 Contributes to Ca 2+ -dependent Triggered Arrhythmias in Pathological Conditions

Rationale: TRPM4 is a Ca 2+ -activated non-selective cation channel that is abundantly expressed in the heart. Mutations in the Trpm4 gene are associated with human cardiac conduction disorders, including Progressive Familial Heart Block type I (PFHBI) and Brugada Syndrome. However, the mechanistic role and in vivo significance of TRPM4 in the triggering of cardiac arrhythmias is still completely unclear.

Objective: To investigate the role of TRPM4 during pathological Ca 2+ handling in the heart.

Methods and results: Using three in vivo pro-arrhythmic assays, we found that Trpm4 -/- mice show a reduced arrhythmic burden compared to control mice. First, aconitine intoxication resulted in severe cardiac arrhythmias, both in WT and Trpm4 -/- animals, but Trpm4 -/- mice developed significantly less ventricular ectopic beats (VEBs) and showed a lower arrhythmic score. Second, during ischemia-reperfusion, induced by 30 min of LAD ligation, significantly more WT animals developed arrhythmias compared to Trpm4 -/- mice. Third, catecholaminergic polymorphic ventricular tachycardia (CPVT) mice, carrying mutations in RyR2, were subjected to a stress test. Significantly more RyR +/R2474S -Trpm4 +/+ animals developed arrhythmias compared to RyR +/R2474S -Trpm4 -/- mice.

Conclusion: Our data establish that TRPM4 represents a novel target in the prevention and treatment of cardiac arrhythmias.

[Reaction on 'Hypomania induced by intranasal corticosteroid fluticasone spray']

<p/>.

Genome-wide DNA methylation changes in two Brassicaceae species sampled alongside a radiation gradient in Chernobyl and Fukushima

The long-term radiological impact to the environment of the nuclear accidents in Chernobyl and Fukushima is still under discussion. In the course of spring of 2016 we sampled two Brassicacea plants, Arabidopsis thaliana and Capsella bursa-pastoris native to Ukraine and Japan, respectively, alongside a gradient of radiation within the exclusion and difficult to return zones of Chernobyl (CEZ) and Fukushima (FEZ). Ambient dose rates were similar for both sampling gradients ranging from 0.5 to 80 μGy/h at plant height. The hypothesis was tested whether a history of several generations of plants growing in enhanced radiation exposure conditions would have led to changes in genome-wide DNA methylation. However, no differences were found in the global percentage of 5-methylated cytosines in Capsella bursa pastoris plants sampled in FEZ. On the other hand a significant decrease in whole genome methylation percentage in Arabidopsis thaliana plants was found in CEZ mainly governed by the highest exposed plants. These data support a link between exposure to changed environmental conditions and changes genome methylation. In addition to methylation the activity concentration of different radionuclides, ¹³⁷Cs, ⁹⁰Sr, ²⁴¹Am and Pu-238,239,240 for CEZ and ^{137, 134}Cs for FEZ, was analysed in both soil and plant samples. The ratio of 5.6 between ¹³⁷Cs compared to ¹³⁴Cs was as expected five years after the FEZ accident. For CEZ ¹³⁷Cs is the most abundant polluting radionuclide in soil followed by ⁹⁰Sr. Whereas ²⁴¹Am and Pu-isotopes are only marginally present. In the plant tissue, however, higher levels of Sr than Cs were retrieved due to a high uptake of ⁹⁰Sr in the plants. The ⁹⁰Sr transfer factors ranged in CEZ from 5 to 20 (kg/kg) depending on the locality. Based on the activity concentrations of the different radionuclides the ERICA tool was used to estimate the total dose rates to the plants. It was found that for FEZ the doses was mainly contributable to the external Cs-isotopes and as such estimated total dose rates (0.13-38 μGy/h) were in the same range as the ambient measured dose rates. In strong contrast this was not true for CEZ where the total dose rate was mainly due to high uptake of the ⁹⁰Sr leading to dose rates ranging from 1 to 370 μGy/h. Hence our data clearly indicate that not taking into account the internal contamination in CEZ will lead to considerable underestimation of the doses to the plants. Additionally they show that it is hard to compare the two nuclear accidental sites and one of the main reasons is the difference in contamination profile.

Supercritical CO₂ Extraction of Nannochloropsis sp.: A Lipidomic Study on the Influence of Pretreatment on Yield and Composition

Algal lipids have gained wide interest in various applications ranging from biofuels to nutraceuticals. Given their complex nature composed of different lipid classes, a deep knowledge between extraction conditions and lipid characteristics is essential. In this paper, we investigated the influence of different pretreatments on lipid extraction with supercritical CO₂ by a lipidomic approach. Pretreatment was found to double the total extraction yield, thereby reaching 23.1 wt.% comparable to the 26.9 wt.% obtained with chloroform/methanol. An increase in acylglycerides was concurrently observed, together with a nearly doubling of free fatty acids indicative of partial hydrolysis. Moreover, an alteration in the distribution of glyco- and phospholipids was noted, especially promoting digalactosyldiglycerides and phosphatidylcholine as compared to monogalactosyldiglycerides and phosphatidylglycerol. At optimized conditions, supercritical CO₂ extraction provided a lipid extract richer in neutral lipids and poorer in phospholipids as compared to chloroform/methanol, though with a very similar fatty acid distribution within each lipid class.

Dietary exposure of the Belgian population to emulsifiers E481 (sodium stearoyl-2-lactylate) and E482 (calcium stearoyl-2-lactylate)

A dietary exposure assessment of food emulsifiers E481 (sodium stearoyl-2-lactylate) and E482 (calcium stearoyl-2-lactylate) in the Belgian population was performed. Nationally representative food consumption data from the Belgian National Food Consumption Surveys 2004 (BNFCS2004) and 2014 (BNFCS2014) were used for calculations. A conservative approach (combining individual food consumption data with the maximum permitted level (MPL) of foods (tier 2), was compared with more refined estimates (combining individual food consumption data with actual concentrations measured in food products available on the Belgian market (tier 3)). Estimated daily intakes were compared to the acceptable daily intake (ADI) of the stearoyl-2-lactylates. The results of tier 2 demonstrated that 92% of the children (3-9 years), 53% of the adolescents (10-17 years), 15% of the adults (18-64 years) and 26% of the elderly (64-98 years) had a potential intake higher than the ADI. When replacing the MPL with maximum analysed concentration levels in foods, daily intake estimates decreased dramatically. The estimated daily intake of the food emulsifiers was below the ADI for all age groups, except for a small percentage of children (1.9%) for which the intake exceeded the ADI. The main contributors to the exposure of E481 and E482 were bread, rolls and fine bakery wares.

Chronic radiation exposure as an ecological factor: Hypermethylation and genetic differentiation in irradiated Scots pine populations

Genetic and epigenetic changes were investigated in chronically irradiated Scots pine (Pinus sylvestris L.) populations from territories that were heavily contaminated by radionuclides as result of the Chernobyl Nuclear Power Plant accident. In comparison to the reference site, the genetic diversity revealed by electrophoretic mobility of AFLPs was found to be significantly higher at the radioactively contaminated areas. In addition, the genome of pine trees was significantly hypermethylated at 4 of the 7 affected sites.

Muscling in on TRP channels in vascular smooth muscle cells and cardiomyocytes

The human TRP protein family comprises a family of 27 cation channels with diverse permeation and gating properties. The common theme is that they are very important regulators of intracellular Ca²⁺ signaling in diverse cell types, either by providing a Ca²⁺ influx pathway, or by depolarising the membrane potential, which on one hand triggers the activation of voltage-gated Ca²⁺ channels, and on the other limits the driving force for Ca²⁺ entry. Here we focus on the role of these TRP channels in vascular smooth muscle and cardiac striated muscle. We give an overview of highlights from the recent literature, and highlight the important and diverse roles of TRP channels in the pathophysiology of the cardiovascular system. The discovery of the superfamily of Transient Receptor Potential (TRP) channels has significantly enhanced our knowledge of multiple signal transduction mechanisms in cardiac muscle and vascular smooth muscle cells (VSMC). In recent years, multiple studies have provided evidence for the involvement of these channels, not only in the regulation of contraction, but also in cell proliferation and remodeling in pathological conditions. The mammalian family of TRP cation channels is composed by 28 genes which can be divided into 6 subfamilies groups based on sequence similarity: TRPC (Canonical), TRPM (Melastatin), TRPML (Mucolipins), TRPV (Vanilloid), TRPP (Policystin) and TRPA (Ankyrin-rich protein). Functional TRP channels are believed to form four-unit complexes in the plasma, each of them expressed with six transmembrane domain and intracellular N and C termini. Here we review the current knowledge on the expression of TRP channels in both muscle types, and discuss their functional properties and role in physiological and pathophysiological processes.

Case Study on Screening Emerging Pollutants in Urine and Nails

Alternative plasticizers and flame retardants (FRs) have been introduced as replacements for banned or restricted chemicals, but much is still unknown about their metabolism and occurrence in humans. We identified the metabolites formed in vitro for four alternative plasticizers (acetyltributyl citrate (ATBC), bis(2-propylheptyl) phthalate (DPHP), bis(2-ethylhexyl) terephthalate (DEHTP), bis(2-ethylhexyl) adipate (DEHA)), and one FR (2,2-bis (chloromethyl)-propane-1,3-diyltetrakis(2-chloroethyl) bisphosphate (V6)). Further, these compounds and their metabolites were investigated by LC/ESI-Orbitrap-MS in urine and finger nails collected from a Norwegian cohort. Primary and secondary ATBC metabolites had detection frequencies (% DF) in finger nails ranging from 46 to 95%. V6 was identified for the first time in finger nails, suggesting that this matrix may also indicate past exposure to FRs as well as alternative plasticizers. Two isomeric forms of DEHTP primary metabolite were highly detected in urine (97% DF) and identified in finger nails, while no DPHP metabolites were detected in vivo. Primary and secondary DEHA metabolites were identified in both matrices, and the relative proportion of the secondary metabolites was higher in urine than in finger nails; the opposite was observed for the primary metabolites. As many of the metabolites present in in vitro extracts were further identified in vivo in urine and finger nail samples, this suggests that in vitro assays can reliably mimic the in vivo processes. Finger nails may be a useful noninvasive matrix for human biomonitoring of specific organic contaminants, but further validation is needed.

Development, validation and evaluation of an analytical method for the determination of monomeric and oligomeric procyanidins in apple extracts

•

Method for simultaneous determination of individual apple procyanidins and catechins is presented.

•

Procyanidins separated on a HILIC column.

•

Accurate quantification achieved using isolated procyanidin oligomers.

•

Method validated via an inter-laboratory evaluation.

There is a lack of data for individual oligomeric procyanidins in apples and apple extracts. Our aim was to develop, validate and evaluate an analytical method for the separation, identification and quantification of monomeric and oligomeric flavanols in apple extracts. To achieve this, we prepared two types of flavanol extracts from freeze-dried apples; one was an epicatechin-rich extract containing ∼30% (w/w) monomeric (−)-epicatechin which also contained oligomeric procyanidins (Extract A), the second was an oligomeric procyanidin-rich extract depleted of epicatechin (Extract B). The parameters considered for method optimisation were HPLC columns and conditions, sample heating, mass of extract and dilution volumes. The performance characteristics considered for method validation included standard linearity, method sensitivity, precision and trueness. Eight laboratories participated in the method evaluation. Chromatographic separation of the analytes was best achieved utilizing a Hilic column with a binary mobile phase consisting of acidic acetonitrile and acidic aqueous methanol. The final method showed linearity for epicatechin in the range 5–100 μg/mL with a correlation co-efficient >0.999. Intra-day and inter-day precision of the analytes ranged from 2 to 6% and 2 to 13% respectively. Up to dp3, trueness of the method was >95% but decreased with increasing dp. Within laboratory precision showed RSD values <5 and 10% for monomers and oligomers, respectively. Between laboratory precision was 4 and 15% (Extract A) and 7 and 30% (Extract B) for monomers and oligomers, respectively. An analytical method for the separation, identification and quantification of procyanidins in an apple extract was developed, validated and assessed. The results of the inter-laboratory evaluation indicate that the method is reliable and reproducible.

Environmental exposure to human carcinogens in teenagers and the association with DNA damage

BACKGROUND

We investigated whether human environmental exposure to chemicals that are labeled as (potential) carcinogens leads to increased (oxidative) damage to DNA in adolescents.

MATERIAL AND METHODS

Six hundred 14-15-year-old youngsters were recruited all over Flanders (Belgium) and in two areas with important industrial activities. DNA damage was assessed by alkaline and formamidopyrimidine DNA glycosylase (Fpg) modified comet assays in peripheral blood cells and analysis of urinary 8-hydroxydeoxyguanosine (8-OHdG) levels. Personal exposure to potentially carcinogenic compounds was measured in urine, namely: chromium, cadmium, nickel, 1-hydroxypyrene as a proxy for exposure to other carcinogenic polycyclic aromatic hydrocarbons (PAHs), t,t-muconic acid as a metabolite of benzene, 2,5-dichlorophenol (2,5-DCP), organophosphate pesticide metabolites, and di(2-ethylhexyl) phthalate (DEHP) metabolites. In blood, arsenic, polychlorinated biphenyl (PCB) congeners 118 and 156, hexachlorobenzene (HCB), dichlorodiphenyltrichloroethane (DDT) and perfluorooctanoic acid (PFOA) were analyzed. Levels of methylmercury (MeHg) were measured in hair. Multiple linear regression models were used to establish exposure-response relationships.

RESULTS

Biomarkers of exposure to PAHs and urinary chromium were associated with higher levels of both 8-OHdG in urine and DNA damage detected by the alkaline comet assay. Concentrations of 8-OHdG in urine increased in relation with increasing concentrations of urinary t,t-muconic acid, cadmium, nickel, 2,5-DCP, and DEHP metabolites. Increased concentrations of PFOA in blood were associated with higher levels of DNA damage measured by the alkaline comet assay, whereas DDT was associated in the same direction with the Fpg-modified comet assay. Inverse associations were observed between blood arsenic, hair MeHg, PCB 156 and HCB, and urinary 8-OHdG. The latter exposure biomarkers were also associated with higher fish intake. Urinary nickel and t,t-muconic acid were inversely associated with the alkaline comet assay.

CONCLUSION

This cross-sectional study found associations between current environmental exposure to (potential) human carcinogens in 14-15-year-old Flemish adolescents and short-term (oxidative) damage to DNA. Prospective follow-up will be required to investigate whether long-term effects may occur due to complex environmental exposures.

Feasibility and quality development of biomaterials in the pretest studies of the German National Cohort

BACKGROUND

The German National Cohort (GNC) is designed to address research questions concerning a wide range of possible causes of major chronic diseases (e.g. cancer, diabetes, infectious, allergic, neurologic and cardiovascular diseases) as well as to identify risk factors and prognostic biomarkers for early diagnosis and prevention of these diseases. The collection of biomaterials in combination with extensive information from questionnaires and medical examinations represents one of the central study components.

OBJECTIVES

In two pretest studies of the German National Cohort conducted between 2011 and 2013, a range of biomaterials from a defined number of participants was collected. Ten study centres were involved in pretest 1 and 18 study centres were involved in pretest 2. Standard operation procedures (SOP) were developed and evaluated to minimize pre-analytical artefacts during biosample collection. Within the pretest studies different aspects concerning feasibility of sample collection/preparation [pretest 1 (a)] and quality control of biomarkers and proteome analyses were investigated [pretest 1 (b), (c)]. Additionally, recruitment of study participants for specific projects and examination procedures of all study centres in a defined time period according to common standards as well as transportation and decentralized storage of biological samples were tested (pretest 2). These analyses will serve as the basis for the biomaterial collection in the main study of the GNC starting in 2014.

MATERIALS AND METHODS

Participants, randomly chosen from the population (n = 1000 subjects recruited at ten study sites in pretest 1) were asked to donate blood, urine, saliva and stool samples. Additionally, nasal and oropharyngeal swabs were collected at the study sites and nasal swabs were collected by the participants at home. SOPs for sample collection, preparation, storage and transportation were developed and adopted for pretest 2. In pretest 2, 18 study sites (n = 599 subjects) collected biomaterials mostly identical to pretest 1. Biomarker analyses to test the quality of the biomaterials were performed.

RESULTS

In pretest 1 and 2, it was feasible to collect all biomaterials from nearly all invited participants without major problems. The mean response rate of the subjects was 95 %. As one important result we found for example that after blood draw the cellular fraction should be separated from the plasma and serum fractions during the first hour with no significant variation for up to 6 h at 4 ℃ for all analysed biomarkers. Moreover, quality control of samples using a proteomics approach showed no significant clustering of proteins according to different storage conditions. All developed SOPs were validated for use in the main study after some adaptation and modification. Additionally, electronic and paper documentation sheets were developed and tested to record time stamps, volumes, freezing times, and aliquot numbers of the collected biomaterials.

DISCUSSION

The collection of the biomaterials was feasible without major problems at all participating study sites. However, the processing times were in some cases too long. To avoid pre-analytical artefacts in sample collection, appropriate standardisation among the study sites is necessary. To achieve this, blood and urine collection will have to be adapted to specific conditions of usage of liquid handling robots, which will be available at all participating study centres in the main study of the GNC. Strict compliance with the SOPs, thorough training of the staff and accurate documentation are mandatory to obtain high sample quality for later analyses. The so obtained biomaterials represent a valuable resource for research on infectious and other common complex diseases in the GNC.

Validated Method for the Characterization and Quantification of Extractable and Nonextractable Ellagitannins after Acid Hydrolysis in Pomegranate Fruits, Juices, and Extracts

Pomegranates are one of the main highly valuable sources of ellagitannins. Despite the potential health benefits of these compounds, reliable data on their content in pomegranates and derived extracts and food products is lacking, as it is usually underestimated due to their complexity, diversity, and lack of commercially available standards. This study describes a new method for the analysis of the extractable and nonextractable ellagitannins based on the quantification of the acid hydrolysis products that include ellagic acid, gallic acid, sanguisorbic acid dilactone, valoneic acid dilactone, and gallagic acid dilactone in pomegranate samples. The study also shows the occurrence of ellagitannin C-glycosides in pomegranates. The method was optimized using a pomegranate peel extract. To quantify nonextractable ellagitannins, freeze-dried pomegranate fruit samples were directly hydrolyzed with 4 M HCl in water at 90 °C for 24 h followed by extraction of the pellet with dimethyl sulfoxide/methanol (50:50, v/v). The method was validated and reproducibility was assessed by means of an interlaboratory trial, showing high reproducibility across six laboratories with relative standard deviations below 15%. Their applicability was demonstrated in several pomegranate extracts, different parts of pomegranate fruit (husk, peels, and mesocarp), and commercial juices. A large variability has been found in the ellagitannin content (150-750 mg of hydrolysis products/g) and type (gallagic acid/ellagic acid ratios between 4 and 0.15) of the 11 pomegranate extracts studied.

Abstract 182: Characterization of Electrophysiological and Conduction Parameters of the Heart in Trpm4-deficient Mice

TRPM4 is a Ca2+-activated non-selective cation channel that belongs to the family of the Transient Receptor Potential (TRP) ion channels. Importantly, TRPM4 is impermeable for Ca2+ and is involved in different Ca2+-dependent cell functions, such as exocytosis, contraction and cell death. Trpm4 is known to be expressed in atrial and ventricular cardiomyocytes. The interest in the functional role of TRPM4 in the heart has risen further by the discovery of Trpm4 mutations that are linked to cardiac conduction disorders, including Progressive Familial Heart Block type I (PFHBI) and Brugada Syndrome. Both gain-of-function and loss-of-function mutation were described in patients with cardiac conduction diseases. Recently, our group showed that TRPM4 plays a role during the late repolarization phase of the action potential in murine ventricular cardiomyocytes and that deletion of the Trpm4 gene leads to shorter ventricular action potentials. To characterize if deletion of Trpm4 has an effect on the conduction properties of the heart, an in depth electrophysiological study was performed in living mice. An octapolar catheter was inserted into the right atrium and ventricle of the heart to measure intracardial electrograms. The atrial-His (AH) and His-ventricular (HV) intervals were calculated and no differences were found between WT and Trpm4-deficient mice. Additionally, more detailed conduction parameters of the heart were determined by use of programmed electrical stimulation (PES) protocols. Sinus node recovery time (SNRT) was not different between WT and Trpm4-deficient mice. Effective refractory period of atrium (AERP), AV node (AVNERP) and ventricle (VERP) were in the same range in WT and Trpm4-deficient mice. Wenckebach periodicity, the parameter for AV nodal conduction, was also not different between WT and Trpm4-deficient mice. These results suggest that deletion of Trpm4 has no effects on the conduction properties of the murine heart.

The Ca(2+)-activated cation channel TRPM4 is a negative regulator of angiotensin II-induced cardiac hypertrophy

Cardiac muscle adapts to hemodynamic stress by altering myocyte size and function, resulting in cardiac hypertrophy. Alteration in myocyte calcium homeostasis is known to be an initial signal in cardiac hypertrophy signaling. Transient receptor potential melastatin 4 protein (TRPM4) is a calcium-activated non-selective cation channel, which plays a role in regulating calcium influx and calcium-dependent cell functions in many cell types including cardiomyocytes. Selective deletion of TRPM4 from the heart muscle in mice resulted in an increased hypertrophic growth after chronic angiotensin (AngII) treatment, compared to WT mice. The enhanced hypertrophic response was also traceable by the increased expression of hypertrophy-related genes like Rcan1, ANP, and α-Actin. Intracellular calcium measurements on isolated ventricular myocytes showed significantly increased store-operated calcium entry upon AngII treatment in myocytes lacking the TRPM4 channel. Elevated intracellular calcium is a key factor in the development of pathological cardiac hypertrophy, leading to the activation of intracellular signaling pathways. In agreement with this, we observed significantly higher Rcan1 mRNA level, calcineurin enzyme activity and protein level in lysates from TRPM4-deficient mice heart compared to WT after AngII treatment. Collectively, these observations are consistent with a model in which TRPM4 is a regulator of calcium homeostasis in cardiomyocytes after AngII stimulation. TRPM4 contributes to the regulation of driving force for store-operated calcium entry and thereby the activation of the calcineurin–NFAT pathway and the development of pathological hypertrophy.