The importance of the ZBED6-IGF2 axis for metabolic regulation in mouse myoblast cells

The transcription factor ZBED6 acts as a repressor of Igf2 and affects directly or indirectly the transcriptional regulation of thousands of genes. Here, we use gene editing in mouse C2C12 myoblasts and show that ZBED6 regulates Igf2 exclusively through its binding site 5'-GGCTCG-3' in intron 1 of Igf2. Deletion of this motif (Igf2^ΔGGCT ) or complete ablation of Zbed6 leads to ~20-fold upregulation of the IGF2 protein. Quantitative proteomics revealed an activation of Ras signaling pathway in both Zbed6^-/- and Igf2^ΔGGCT myoblasts, and a significant enrichment of mitochondrial membrane proteins among proteins showing altered expression in Zbed6^-/- myoblasts. Both Zbed6^-/- and Igf2^ΔGGCT myoblasts showed a faster growth rate and developed myotube hypertrophy. These cells exhibited an increased O₂ consumption rate, due to IGF2 upregulation. Transcriptome analysis revealed ~30% overlap between differentially expressed genes in Zbed6^-/- and Igf2^ΔGGCT myotubes, with an enrichment of upregulated genes involved in muscle development. In contrast, ZBED6-overexpression in myoblasts led to cell apoptosis, cell cycle arrest, reduced mitochondrial activities, and ceased myoblast differentiation. The similarities in growth and differentiation phenotypes observed in Zbed6^-/- and Igf2^ΔGGCT myoblasts demonstrates that ZBED6 affects mitochondrial activity and myogenesis largely through its regulation of IGF2 expression. This study adds new insights how the ZBED6-Igf2 axis affects muscle metabolism.

Consequences of undetected olfactory loss for human chemosensory communication and well-being

Olfactory perception has implications for human chemosensory communication and in a broader context, it affects well-being. However, most of the studies investigating the consequences of olfactory loss have recruited patients who have already been categorized as having a dysfunctional sense of smell and sought help in an ENT clinic. We revisit these findings by distinguishing subjects with olfactory impairment from a group of subjects who all declared a normal sense of smell when enrolling for this study. In the initial sample of 203 individuals, we found 59 to have impaired olfaction and four with marginal olfactory performance, not useful in daily life. Interestingly, we found a significant between-group difference in cognitive functioning, further supporting the notion of the relationship between cognition and olfactory performance. However, their chemosensory communication and well-being appeared not to be different from subjects with normosmia. Impaired olfactory function certainly has a severe impact on daily life but more so in individuals who are bothered with it and decide to seek treatment. The limited-to-no olfactory perception in the fraction of subjects who neither complain about it nor seek help in ENT clinics does not seem to have a major effect on their social, cognitive, emotional and health functioning. This article is part of the Theo Murphy meeting issue 'Olfactory communication in humans'.

Health-promoting factors in higher education for a sustainable working life - protocol for a multicenter longitudinal study

BACKGROUND

The World Health Organization has highlighted the importance of health promotion for health service providers in order to ensure sustainable working life for individuals involved in providing health services. Such sustainability begins when students are preparing to manage their own future health and welfare in working life. It has been suggested that universities, employees and trainee health professionals should adopt or follow a salutogenic approach that not only complements the providing of information on known health risks but also favors health promotion strategies. This paper describes the study design and data collection methods in a planned study aiming to explore health-promoting factors for a sustainable working life among students in higher education within healthcare and social work.

METHODS

This protocol describes a multicenter longitudinal study involving Swedish students on higher education programs in the healthcare and social work sectors. In 2018, the study invited students on seven education programs at six universities to participate. These programs were for qualification as: biomedical laboratory scientists (n = 121); dental hygienists (n = 87); nurses (n = 1411); occupational therapists (n = 111); physiotherapists (n = 48); radiographers (n = 60); and, social workers (n = 443). In total, 2283 students were invited to participate. Participants completed a baseline, a self-reported questionnaire including six validated instruments measuring health-promoting factors and processes. There are to be five follow-up questionnaires. Three while the students are studying, one a year after graduating, and one three years after graduating. Each questionnaire captures different health-promoting dimensions, namely: health-promoting resources (i.e. sense of coherence); occupational balance; emotional intelligence; health and welfare; social interaction; and work and workplace experiences/perceptions.

DISCUSSION

This study focuses on the vastly important aspect of promoting a sustainable working life for healthcare and social work employees. In contrast to previous studies in this area, the present study uses different, validated instruments in health promotion, taking a salutogenic approach. It is hoped that, by stimulating the implementation of new strategies, the study's findings will lead to education programs that prepare students better for a sustainable working life in healthcare and social work.

A Discovery of a Genetic Mutation Causing Reduction of Atrogin-1 Expression in Broiler Chicken Muscle

Chickens are bred all over the world and have significant economic value as one of the major agricultural animals. The growth rate of commercial broiler chickens is several times higher than its Red Jungle fowl (RJF) ancestor. To further improve the meat production of commercial chickens, it is quite important to decipher the genetic mechanism of chicken growth traits. In this study, we found that broiler chickens exhibited lower levels of E3 ubiquitin ligase muscle atrophy F-box (MAFbx or Atrogin-1) relative to its RJF ancestor. As a ubiquitin ligase, Atrogin-1 plays a crucial role in muscle development in which its up-regulation often indicates the activation of muscle atrophic pathways. Here, we showed that the Atrogin-1 expression variance partly affects chicken muscle growth rates among different breeds. Furthermore, we demonstrated that the reduced expression of Atrogin-1 in broiler chickens was ascribed to a single nucleotide polymorphism (SNP), which inhibited the binding of transcription regulators and attenuated the enhancer activity. The decreased Atrogin-1 in broiler chickens suppresses the catabolism of muscle protein and preserves muscle mass. Our study facilitates the understanding of the molecular mechanism of chicken muscle development and has a high translational impact in chicken breeding.

Abstract P4-14-06: A study of adverse vascular effects of adjuvant therapy with aromatase inhibitors in women with breast cancer

Background: There is a debate concerning risk of cardiovascular disease (CVD) from adjuvant therapy with aromatase inhibitors (AI). Randomized trials have indicated higher CV risk and one observational study higher risk of myocardial infarction, whereas other studies have pointed out no elevated risk. The first morphological sign of developing atherosclerosis is a thickening of the arterial intima layer, whereas in the longer perspective the media layer gets thinner - a process not captured when using conventional Carotid intima-media-thickness (CIMT). We therefore used high resolution ultrasound (HRU), to separately estimated the intima and media layers and calculate the I/M thickness ratio. A thicker intima and higher I/M thickness ratio are signs of adverse vascular effects. This principle of estimating vascular aging can strongly distinguish 70-yr old subjects with and w/o prevalent CVD, yielding C-values up to 0.90 in ROC-analysis.

Patients and Methods: We included 150 postmenopausal breast cancer women of whom 50 were treated with AI during at least 3 years, 50 with at least 3 years of tamoxifen and 50 were without endocrine therapy. Patients were investigated with non-invasive HRU (22MHz) of the common carotid artery (CCA). Non-parametric statistical methods were used, including Bootstrap quantile regression to obtain 95% confidence intervals (CI) and adjustment for potential confounders: age, smoking, use of statins, HbA1c and previous HRT.

Results: Of 150 included women, 132 remained having a technically acceptable ultra sound scans and no AI therapy before tamoxifen therapy; AI (#48); tamoxifen (#40) and no anti-hormone therapy (#44). Corresponding median ages were 66, 65 and 65 yrs and median treatment durations were 54 (AI) and 58 (tamoxifen) months.

AI therapy, compared to tamoxifen, showed a significantly thicker CCA-intima layer, p = 0.031. However, mean values of both CCA-intima thickness and I/M thickness ratio were very similar in the tamoxifen and the no anti-estrogen group; Thus, AI compared to the other two groups combined, had a significantly thicker intima layer (p = 0.009) and higher I/M ratio (p = 0.047), both indicating adverse vascular effects from AI therapy. After adjustment for potential confounders, AI therapy still showed a thicker CCA intima layer of 0.015 mm (95% CI .003, .027); p = 0.016.

In contrast, corresponding analysis using conventional Carotid intima-media thickness (CIMT), revealed no significant group differences or association to AI treatment duration.

Conclusion: More than three years of adjuvant therapy with aromatase inhibitors, compared to women having no anti-estrogen therapy or tamoxifen, was associated with signs of adverse vascular effects; thicker intima layer and higher intima/media ratio of the common carotid artery. After adjustment, the thicker intima layer remained significant. These findings are in accordance with reports of increased risk of cardiovascular events following adjuvant therapy with aromatase inhibitors.

Citation Format: Lindman H, Dahlberg L, Larsson M, Naessén T. A study of adverse vascular effects of adjuvant therapy with aromatase inhibitors in women with breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-14-06.

Perioperative Hyperlactemia Is a Poor Predictor of Outcome in Patients Undergoing Surgery for Acute Type-A Aortic Dissection

OBJECTIVE

In patients presenting with acute type-A aortic dissection (aTAAD), lactic acid measurement is a frequently used analysis for diagnosis of acute ischemia, which may have a dismal prognosis. The aim of the current study was to determine the performance of perioperative arterial lactic acid measurements in predicting outcome in aTAAD patients.

DESIGN

Retrospective, observational study.

SETTING

Cardiothoracic surgery unit at a tertiary-level hospital.

PARTICIPANTS

The study involved 285 consecutive patients undergoing surgery for aTAAD.

INTERVENTIONS

Preoperative and postoperative lactic acid levels were measured and evaluated together with clinical data related to outcome, including in-hospital and 1-year mortality.

MEASUREMENTS AND MAIN RESULTS

Altogether, 37 patients (13%) died during the index hospital admission, and survival was 84.4 ± 2.2 at 1 year. Preoperative cardiac malperfusion (odds ratio [OR] 3.1; 95% confidence interval [CI] 1.3-7.3) and cerebral malperfusion (OR 2.6; 95% CI 1.2-5.6) were associated significantly with poorer 1-year survival. The area under the curve (AUC) for in-hospital and 1-year mortality in relation to preoperative lactic acid levels was 0.684 and 0.673, respectively, corresponding to a lactic acid cut-off for in-hospital mortality of 2.75 mmol/L (sensitivity 56%; specificity 72%) and a cut-off for 1-year mortality of 2.85 mmol/L (sensitivity 48%; specificity 74%). The AUC for in-hospital and 1-year mortality in relation to lactic acid levels measured postoperatively on arrival at the intensive care unit was 0.582 and 0.498, respectively.

CONCLUSION

Although hyperlactemia in aTAAD indicates an increased risk of postoperative mortality, the sole use of lactic acid levels as a tool for accurate assessment of postoperative mortality is inadvisable due to its poor discriminatory performance.

Low-Energy Collisions of Protonated Enantiopure Amino Acids with Chiral Target Gases

Here we report on the gas-phase interactions between protonated enantiopure amino acids (L- and D-enantiomers of Met, Phe, and Trp) and chiral target gases [(R)- and (S)-2-butanol, and (S)-1-phenylethanol] in 0.1-10.0 eV low-energy collisions. Two major processes are seen to occur over this collision energy regime, collision-induced dissociation and ion-molecule complex formation. Both processes were found to be independent of the stereo-chemical composition of the interacting ions and targets. These data shed light on the currently debated mechanisms of gas-phase chiral selectivity by demonstrating the inapplicability of the three-point model to these interactions, at least under single collision conditions. Graphical Abstract.

Association between angiogenic factors and signs of arterial aging in women with pre-eclampsia

OBJECTIVE

Pre-eclampsia (PE) is associated with an increased risk of cardiovascular disease later in life. In cases with PE there is a substantial increase in levels of the antiangiogenic factor soluble fms-like tyrosine kinase-1 (sFlt-1) and decreased levels of the proangiogenic factor placental growth factor (PlGF). Elevated levels of sFlt-1 are also found in individuals with cardiovascular disease. The aims of this study were to assess levels of sFlt-1, PlGF and the sFlt-1/PlGF ratio and their correlation with signs of arterial aging by measuring the common carotid artery (CCA) intima and media thicknesses and their ratio (I/M ratio) in women with and without PE.

METHODS

Serum sFlt-1 and PlGF levels were measured using commercially available enzyme-linked immunosorbent assay kits, and CCA intima and media thicknesses were estimated using high-frequency (22-MHz) ultrasonography in 55 women at PE diagnosis and in 64 women with normal pregnancy at a similar gestational age, with reassessment at 1 year postpartum.

RESULTS

During pregnancy, higher levels of sFlt-1, lower levels of PlGF, a thicker intima, a thinner media and a higher I/M ratio of the CCA were found in women with PE vs controls (all P < 0.0001). Further, sFlt-1 and the sFlt-1/PlGF ratio were positively correlated with intima thickness and I/M ratio (all P < 0.0001). At 1 year postpartum, levels of sFlt-1 and the sFlt-1/PlGF ratio had decreased in both groups; however, their levels in the PE group were still higher than in the controls (P = 0.001 and < 0.0001, respectively). Levels of sFlt-1 and the sFlt-1/PlGF ratio remained positively correlated with intima thickness and I/M ratio at 1 year postpartum.

CONCLUSIONS

Higher sFlt-1 levels and sFlt-1/PlGF ratio in women with PE were positively associated with signs of arterial aging during pregnancy. At 1 year postpartum, sFlt-1 levels and the sFlt-1/PlGF ratio were still higher in the PE group and were associated with the degree of arterial aging. © 2016 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.

Flow-aligned, single-shot fiber diffraction using a femtosecond X-ray free-electron laser

A major goal for X-ray free-electron laser (XFEL) based science is to elucidate structures of biological molecules without the need for crystals. Filament systems may provide some of the first single macromolecular structures elucidated by XFEL radiation, since they contain one-dimensional translational symmetry and thereby occupy the diffraction intensity region between the extremes of crystals and single molecules. Here, we demonstrate flow alignment of as few as 100 filaments (Escherichia coli pili, F-actin, and amyloid fibrils), which when intersected by femtosecond X-ray pulses result in diffraction patterns similar to those obtained from classical fiber diffraction studies. We also determine that F-actin can be flow-aligned to a disorientation of approximately 5 degrees. Using this XFEL-based technique, we determine that gelsolin amyloids are comprised of stacked β-strands running perpendicular to the filament axis, and that a range of order from fibrillar to crystalline is discernable for individual α-synuclein amyloids.

Caretakers' barriers to pediatric antiretroviral therapy adherence in Vietnam - A qualitative and quantitative study

BACKGROUND

Poor antiretroviral therapy (ART) adherence leads to drug resistance and treatment failures. The options for second and third line ART regimens, particularly for pediatric patients, are very limited in low and middle-income countries. HIV-infected children are mostly passive drug-takers, thus caretakers play a very important role in assuring ART adherence. Pediatric ART adherence is still a challenging problem in Vietnam since non-adherence is the major risk factor for treatment failure. Our study explores and measures caretakers' barriers in order to improve pediatric ART adherence in future.

METHODS

Exploring caretakers' barriers was conducted through a qualitative study with Focus Group Discussion (FGD) on two topics: 1. Current society - family support and difficulties in taking care children under ART; 2. Stigma experience. Based on the finding from the qualitative study a quantitative study measuring caretakers' barriers was conducted through a designed questionnaire. Study methods strictly followed the consolidated criteria with 32-item checklist for interviews and focus groups.

RESULTS

In total eight FGDs with 53 participants were conducted. Common caretakers' barriers to children's ART adherence, were financial burden, lack of ART KP (Knowledge-Practice), stigma, depression, shifting caretaker, drug taste and side effects, lack of family support, fixed health check-up schedule and HIV non-disclosure. In the questionnaire study a total of 209 caretakers participated. The most commonly reported caretakers' barriers were: financial burden (144; 69%), KP burden (143; 68%), depression (85; 41%) and stigma (30; 14.8%). Some caretakers' characteristics that significantly associated with reported barriers (p<0.05). Rural caretakers reported significantly more financial burden (OR=2.26) and stigma (OR=3.53) than urban. Caretakers with under high school level education reported significantly more financial burdens (OR=2.08) and stigma (OR=4.15) compared to caretakers with high school education or over.

CONCLUSION

Financial burden, KP burden, depression and stigma were common reported caretakers' barriers to pediatric ART adherence. Family residence, caretaker's education level and job were considered as the key factors determining caretakers' barriers related to financial burden and stigma. These findings may be important for policy makers and researchers in order to develop effective interventions regarding to caretakers' burdens and associated factors. Furthermore, a tool for nurses in monitoring caretakers' barriers to pediatric ART adherence was developed first with FDG, and then interview questionnaire. This tool could be applied and modified easily in any pediatric ART clinic settings in accordance to economic, social and cultural circumstances.

A General Method for Targeted Quantitative Cross-Linking Mass Spectrometry

Chemical cross-linking mass spectrometry (XL-MS) provides protein structural information by identifying covalently linked proximal amino acid residues on protein surfaces. The information gained by this technique is complementary to other structural biology methods such as x-ray crystallography, NMR and cryo-electron microscopy[1]. The extension of traditional quantitative proteomics methods with chemical cross-linking can provide information on the structural dynamics of protein structures and protein complexes. The identification and quantitation of cross-linked peptides remains challenging for the general community, requiring specialized expertise ultimately limiting more widespread adoption of the technique. We describe a general method for targeted quantitative mass spectrometric analysis of cross-linked peptide pairs. We report the adaptation of the widely used, open source software package Skyline, for the analysis of quantitative XL-MS data as a means for data analysis and sharing of methods. We demonstrate the utility and robustness of the method with a cross-laboratory study and present data that is supported by and validates previously published data on quantified cross-linked peptide pairs. This advance provides an easy to use resource so that any lab with access to a LC-MS system capable of performing targeted quantitative analysis can quickly and accurately measure dynamic changes in protein structure and protein interactions.

Signatures of Hyperfine, Spin-Orbit, and Decoherence Effects in a Pauli Spin Blockade

We detect in real time interdot tunneling events in a weakly coupled two-electron double quantum dot in GaAs. At finite magnetic fields, we observe two characteristic tunneling times T_{d} and T_{b}, belonging to, respectively, a direct and a blocked (spin-flip-assisted) tunneling. The latter corresponds to the lifting of a Pauli spin blockade, and the tunneling times ratio η=T_{b}/T_{d} characterizes the blockade efficiency. We find pronounced changes in the behavior of η upon increasing the magnetic field, with η increasing, saturating, and increasing again. We explain this behavior as due to the crossover of the dominant blockade-lifting mechanism from the hyperfine to spin-orbit interactions and due to a change in the contribution of the charge decoherence.

A genome-wide association study of kynurenic acid in cerebrospinal fluid: implications for psychosis and cognitive impairment in bipolar disorder

Elevated cerebrospinal fluid (CSF) levels of the glia-derived N-methyl-D-aspartic acid receptor antagonist kynurenic acid (KYNA) have consistently been implicated in schizophrenia and bipolar disorder. Here, we conducted a genome-wide association study based on CSF KYNA in bipolar disorder and found support for an association with a common variant within 1p21.3. After replication in an independent cohort, we linked this genetic variant-associated with reduced SNX7 expression-to positive psychotic symptoms and executive function deficits in bipolar disorder. A series of post-mortem brain tissue and in vitro experiments suggested SNX7 downregulation to result in a caspase-8-driven activation of interleukin-1β and a subsequent induction of the brain kynurenine pathway. The current study demonstrates the potential of using biomarkers in genetic studies of psychiatric disorders, and may help to identify novel drug targets in bipolar disorder.

Gliptin-mediated neuroprotection against stroke requires chronic pretreatment and is independent of glucagon-like peptide-1 receptor

Gliptins are anti-type 2 diabetes (T2D) drugs that regulate glycaemia by preventing endogenous glucagon-like peptide-1 (GLP-1) degradation. Chronically administered gliptins before experimental stroke can also induce neuroprotection, and this effect is potentially relevant for reducing brain damage in patients with T2D and high risk of stroke. It is not known, however, whether acute gliptin treatment after stroke (mimicking a post-hospitalization treatment) is neuroprotective or whether gliptin-mediated neuroprotection occurs via GLP-1-receptor (GLP-1R) activation. To answer these two questions, wild-type and glp-1r(-/-) mice were subjected to transient middle cerebral artery occlusion (MCAO). Linagliptin was administered acutely (50 mg/kg intravenously), at MCAO time or chronically (10 mg/kg orally) for 4 weeks before and 3 weeks after MCAO. Neuroprotection was assessed by stroke volume measurement and quantification of NeuN-positive surviving neurons. Plasma/brain GLP-1 levels and dipeptidyl peptidase-4 activity were also measured. The results show that the linagliptin-mediated neuroprotection against stroke requires chronic pretreatment and does not occur via GLP-1R. The findings provide essential new knowledge with regard to the potential clinical use of gliptins against stroke, as well as a strong impetus to identify gliptin-mediated neuroprotective mechanisms.