bluuebunny/crossref_metadata_2025 huggingface dataset:
Age alters peripheral vascular endothelial function without affecting coronary flow reserve in healthy volunteers
Authors: Bouly M , Bourguignon M.P , Ley S , Xuereb L , Bernhardt P , Tyl B
Published: November 2020

Background

Age is a key risk factor contributing to vascular endothelial dysfunction. Whether the impact of ageing is uniform on various vascular beds is unknown. Endothelial function is classically evaluated by the brachial flow mediated dilatation (FMD) after a brief occlusion which mainly involves nitric oxide (NO) production. However, FMD measurement, requiring highly trained technicians, has been shown to be associated with a high degree of variability. Endothelial function could be also assessed by cutaneous iontophoresis combined with Laser Doppler. By contrast to FMD, this method is easily done by nurses and shows less variability. In parallel, myocardial imaging allows measurement of coronary flow reserve (CFR) coupled with an adenosine challenge leading to both a NO release and a modulation of potassium channels.

Purpose

The aim of this study was to determine the impact of ageing on vasodilation of peripheral (cutaneous) and coronary blood vessels in healthy volunteers.

Methods

This prospective single German center study enrolled 75 healthy non-smoking normotensive volunteers, taking no medication. They were divided into three age-subgroups (n=25/group): 18–30, 50–59, and 60–70 years (women: 54, 27 and 23%, respectively). All subjects underwent clinical and laboratory evaluation.

Peripheral endothelial function, expressed in cutaneous blood flow (delta CBF), was assessed through cutaneous microcirculation dilation by the non-invasive method using Laser Doppler Speckle Contrast Imaging (LSCI, Perimed) coupled with iontophoresis to locally deliver 125 nmoles of acetylcholine (Ach). The CFR was determined by cardiac magnetic resonance (CMR) coupling with an intravenous infusion of adenosine at 140 μg/kg/min for at least 3 minutes.

Results

Age was associated with a 23% reduction of peripheral endothelial function (delta CBF, p=0.005) in the elderly group (60–70y) vs. the younger one (18–30y) (median: 56.4 vs. 73.6). By contrast, calculated CFR was unchanged (median: 4.1 vs. 4.2, p=0.38). No relationship was observed between peripheral endothelial function (delta CBF) and CFR (r=0.01, p>0.97) in healthy volunteers.

Conclusion

In healthy volunteers, ageing is associated with a progressive peripheral but not with a coronary vascular dysfunction. This suggests that the impact of age on endothelial dysfunction depends on different vascular beds. Peripheral endothelial function assessment does not predict coronary vascular function in healthy volunteers.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Servier
Systemic microvascular endothelial dysfunction is associated with reduction of left ventricular ejection fraction in chronic Chagas disease patients
Authors: Kasal D , Britto A , De Lorenzo A , Verri V , Tibirica E
Published: November 2020

Introduction

Chagas disease (CD) affects millions of patients around the world, many of whom may develop cardiovascular complications, including heart failure and stroke. Notwithstanding, little is known about the effects of CD in the reactivity of the systemic microcirculation.

Purpose

The present study aims to compare the microvascular reactivity (MR) of a group of patients in the chronic phase of CD with healthy volunteers, matched for sex and age. In addition, we sought to evaluate the association between MR and left ventricular ejection fraction (LVEF) in CD patients.

Methods

Systemic microvascular flow and endothelium-dependent vasodilation were assessed using laser speckle contrast imaging, coupled with acetylcholine (Ach) iontophoresis in the forearm skin. Vascular reactivity data were expressed as area under the curve (AUC) of Ach-induced vasodilation. Anthropometry, medications, biochemistry, and echocardiographic data were obtained from medical records.

Results

Thirty-six patients were compared to 25 healthy individuals (controls). Ach-induced vasodilation was higher in controls, when compared to patients (maximum increase of microvascular flow from baseline of 106% and of 48% respectively, P<0.0001; Mann Whitney test). There was a significant association between LVEF, stratified into quartiles, and MR (P value for linear trend = 0.002; one way ANOVA, Figure 1). In addition, there was no difference in MR between CD patients with normal LVEF and the control group. In CD patients, MR was independent of the presence of arterial hypertension or diabetes.

Conclusion

We have shown that the reduction of MR is associated with a decrease of LVEF in a group of chronic CD patients. The results were not affected by comorbidities, such as hypertension or diabetes. The evaluation of systemic endothelial function may be useful to tailor therapeutic and preventive approaches, targeted at systolic left ventricular failure associated with chronic CD cardiomyopathy.

Figure 1

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro
Beta3-adrenergic stimulation restores endothelial mitochondrial dynamics and prevents pulmonary arterial hypertension
Authors: Oliver E , Rocha S.F , Spaczynska M , Lalama D.V , Gomez M , Fuster V , Ibanez B
Published: November 2020

Background

Endothelial dysfunction is one of the most important hallmarks of pulmonary arterial hypertension (PAH). This leads to anomalous production of vasoactive mediators that are responsible for a higher vascular tone and a subsequent increase in pulmonary artery pressure (PAP), and to an increased vascular permeability that favors perivascular inflammation and remodeling, thus worsening the disease. Therefore, preservation of the endothelial barrier could become a relevant therapeutic strategy.

Purpose

In previous studies, others and we have suggested the pharmacological activation of the β3-adrenergic receptor (AR) as a potential therapeutic strategy for pulmonary hypertension (PH) due to left heart disease. However, its potential use in other forms of PH remain unclear. The aim of the present study was to elucidate whether the β3-AR agonist mirabegron could preserve pulmonary endothelium function and be a potential new therapy in PAH.

Methods

For this purpose, we have evaluated the effect of mirabegron (2 and 10 mg/kg·day) in different animal models, including the monocrotaline and the hypoxia-induced PAH models in rats and mice, respectively. Additionally, we have used a transgenic mouse model with endothelial overexpression of human β3-AR in a knockout background, and performed in vitro experiments with human pulmonary artery endothelial cells (HPAECs) for mechanistic experiments.

Results

Our results show a dose dependent effect of mirabegron in reducing mean PAP and Right Ventricular Systolic Pressure in both mice and rats. In addition, the use of transgenic mice has allowed us to determine that pulmonary endothelial cells are key mediators of the beneficial role of β3-AR pathway in ameliorating PAH. Mechanistically, we have shown in vitro that activation of β3-AR with mirabegron protects HPAECs from hypoxia-induced ROS production and mitochondrial fragmentation by restoring mitochondrial fission/fusion dynamics.

Conclusions

This protective effect of mirabegron would lead to endothelium integrity and preserved pulmonary endothelial function, which are necessary for a correct vasodilation, avoiding increased permeability and remodeling. Altogether, the current study demonstrates a beneficial effect of the β3-AR agonist mirabegron that could open new therapeutic avenues in PAH.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Programa de Atracciόn de Talento, Comunidad de Madrid
Pulmonary arterial hypertension modeling with synthetic stable thromboxane A2 analogue (U46619) in porcine: dose adjustment and acute hemodynamic reactions
Authors: Goncharova N , Andreeva E , Vakhrushev A , Condori Leandro H.I , Murashova L , Voronin S , Korobchenko L , Mitrofanova L , Moiseeva O , Mikhaylov E
Published: November 2020

Introduction

Survival in PAH is strongly associated with adaptation of the RV to pressure overload.

Purpose

To investigate acute hemodynamic reactions during infusion of the stable thromboxane A2 (TXA2) analogue U46619 in a porcine model.

Materials and methods

The study comprised 9 male Landrace pigs (32.7±3.8 kg) under GA. After heparinization, PAH was induced by continuous and stepwise increasing infusion of U46619 (10 mg/ml; Tocris, USA) according to a pre-specified protocol. The target mPAP was 40 mmHg. Hemodynamics was assessed, cardiac output (CO) was calculated using the Fick equation before and during U46619 infusion.

Results

U46619 infusion at a previously published rate 0.1, 0.2 μg kg–1 min–1 in pig 1 resulted in rapid hemodynamic deterioration. Two-time reduced U46619 dose infusione resulted in a target mPAP but severe mBP drop in 1, 3, 4 pigs and required cathecholamine support. The U46619 dosage was reduced up to ¼ (0.025, 0.05, 0.075, 0.1, 0.12, 0.15, 0.175 μg kg–1 min–1). In animals on 1/4 dosage U46619 infusion, heart rate (HR), mBP, mPAP, RAP and PVR reliably increased and BP was stable (Table 1). There was a positive correlation between the mPAP and heart rate (HR) on U46619 infusion (r=0.66; t=2.38; p=0.048) and between CO and mBP (r=0.66; t=2.36; p=0.04). Low CO was associated with high PVR (r=−0.98; t=−14.3; p<0,001). Positive correlation between PVR and SVR was revealed (r=0.96; p=0.00002). In 3 pigs with severe mBP drop and PAH right ventricle subendocardial hemorrhage was revealed on autopsy study.

Conclusions

High dose U46619 infusion was associated with acute RV decompensation due to pressure overload accompanied with systemic BP drop and low CO. Lower dosages of U46619 infusion were characterized by stable target mean PAP. HR acceleration and mean systemic BP are of compensation mechanisms for cardiac output maintenance in PAH.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): RFBR grant 18-315-20050
Shear stress induced activation of von Willebrand factor may predispose to gastrointestinal bleeding in syndrome of Heyde
Authors: Avtaeva Y.N , Melnikov I.S , Komlev A.E , Imaev T.E , Okhota S.D , Kozlov S.G , Gabbasov Z.A
Published: November 2020

Introduction

Von Willebrand factor (vWF) changes conformation from globular to fibrillar in the range of shear rates above 5000 s-1. High shear rates, observed in severe aortic stenosis, create conditions for activation of vWF, which opens up access for platelets and coagulation factors to the previously hidden domains of the molecule. At the same time, vWF undergoes increased degradation by metalloproteinase ADAMTS13. Proteolytic cleavage of vWF leads to deficiency of hemostatically active high molecular weight multimers (HMWM) of vWF, while its mass concentration remains unaltered. This results in the development of acquired von Willebrand disease type 2A (vWD) and concomitant gastrointestinal bleeding. The combination of acquired vWD 2A and gastrointestinal bleeding, developed due to severe aortic stenosis, is called Heyde's syndrome. The correlation of shear stress activation of vWF and gastrointestinal bleeding in patients with Heyde's syndrome remains poorly studied.

The aim of the study was to measure vWF-mediated platelet adhesion to fibrinogen-coated surfaces under shear rates higher than 5000 s-1 in whole blood samples of healthy volunteers and patients with Heyde's syndrome.

Methods

A microfluidic system simulating blood flow in vessels was used to assess platelet adhesion. Platelet adhesion was measured by an increase in the intensity of laser radiation scattered from a fibrinogen-coated surface during a 15 minutes circulation of whole blood samples through a flow chamber under shear rates higher than 5000 s-1. Platelets in whole blood samples were activated with 5 μM ADP prior to measurement. The study included 5 patients with Heyde's syndrome 55–80 years old. The control group included 6 healthy volunteers 25–55 years old. vWF-mediated platelet adhesion was detected by blocking platelet-vWF binding with anti-GPIb monoclonal antibody (mAb). Fibrinogen-mediated platelet adhesion was detected by blocking platelet GPIIb/IIIa receptors with mAb.

Result

The inhibition of GPIb vWF-receptor reduced platelet adhesion by 7.6±3.5% (p<0.05) in patients with Heyde's syndrome, and by 16.5±3.3% (p<0.05) in healthy volunteers. The inhibition of GPIIb/IIIa fibrinogen receptor reduced platelet adhesion by 96±7% (p<0.05) in patients with Heyde's syndrome, and by 80.2±6.6% (p<0.05) in healthy volunteers.

Conclusion

Significantly reduced contribution of vWF to platelet adhesion under shear rates higher than 5000 s-1 may indicate a decrease in hemostatically active HMWM of vWF. Shear stress activation of vWF in the range of high shear rates and its subsequent inactivation by ADAMTS13 may lead to functional vWF deficiency and the development of gastrointestinal bleeding in Heyde's syndrome.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): The Russian Science Foundation
Shaping the future of metabolic syndrome: genetics, prognosis and individual tailoring
Authors: Sousa J.A , Mendonca M.I , Pereira A , Monteiro J.P , Temtem A.M , Santos M , Mendonca F.V , Sousa A.C , Rodrigues M , Henriques E , Ornelas I , Freitas A.I , Freitas A.D , Reis P
Published: November 2020

Background

Metabolic syndrome (MetS), characterized by a cluster of cardiovascular risk factors, is considered to be the major health hazard of modern world and a 21st century epidemic. Recent GWAS have identified several susceptibility regions involved in lipid metabolism and oxidation, also associated with MetS. Genetic risk score (GRS) is an emerging method that attempts to establish correlation between SNPs and clinical phenotypes.

Aim

Evaluate the value of a GRS encompassing SNPs involved in lipidic metabolism and oxidation pathways, in predicting CAD outcome (MACEs and long-term cardiovascular Mortality) in a coronary population with MetS.

Methods

1101 coronary patients and MetS, were selected from the GENEMACOR study. Genotyping was performed by TaqMan allelic discrimination assay. A Multiplicative score (mGRS) was constructed according to the multiplicative model with variants belonging to the lipid and oxidative axes (PSRC1, PCSK9, KIF6, ZNF259, LPA, APO E, PON192, PON108, PON55, MTHFR677, MTHFR1298, MTHFD1L). This GRS was categorized using the mean (higher vs lower than mean). Cumulate Mortality Hazards Model (Cox regression) adjusted for age, gender, smoking, hypertension, dyslipidaemia, diabetes, hsCRP, eGFR, Ejection fraction (EF), and multivessel disease) was used to find independent predictors of cardiovascular outcome. We performed Kaplan-Meier Survival curves for both groups (higher vs lower than mean GRS) and log-rank test to compare survival distributions in both groups.

Results

The following variables have emerged independently associated with time to MACE occurrence: mGRS (HR=1.31 95% CI (1.07; 1.59); p=0.008), male gender, EF and multivessel disease. Concerning cardiovascular mortality, mGRS also remained an independent predictor (HR=1.44 (1.04–1.99); p=0.028) alongside age, smoking, diabetes and EF. The Log-Rank test showed significant differences between the two curves related to MACE occurrence and cardiovascular mortality (p=0.001 and 0.002, respectively). The Kaplan-Meier survival showed that as mGRS increases, patient survival decreases.

Conclusion

In patients with MetS, a GRS comprising variants in lipidic and oxidative pathways, proved to be a useful stratification tool, identifying patients likely to have a worst prognosis over time. Our data further underlines the additive potential and clinical utility of genetic information in shaping secondary prevention.

Figure 1

Funding Acknowledgement

Type of funding source: None
An increase in activated NKT-CD8+ cells is associated with the presence of hypoechoic carotid plaques
Authors: Genkel V , Baturina I , Emelyanov I , Shaposhnik I , Dolgushin I
Published: November 2020

Background

The role of NK-cells and NKT-cells and their subtypes at various stages of the development of atherosclerosis is poorly understood. It was previously shown that CD3+CD56+CD8+ cells can secrete pro-inflammatory cytokines and an increase in their number has been established in patients with active Behçet's Disease and Multiple Sclerosis.

Purpose

To study the relationship between the number of activated CD3+CD56+CD8+ cells and the echogenicity of plaques in patients with carotid atherosclerosis.

Methods

The study included 40 patients, 21 (52.5%) men and 19 (47.5%) women who underwent carotid ultrasound and immunological studies. The median age was 53.5 (46.7; 57.0) years. All patients underwent duplex ultrasound scanning of the carotid arteries. If an atherosclerotic plaque was detected, its image was saved and exported to Adobe Photoshop CS6® followed by analysis of the gray-scale median (GSM) of the plaque. Hypoechoic was considered a carotid plaque whose GSM values were less than 50. The number of CD3+CD56+CD8+CD11b+ cells was evaluated by flow cytometry using a flow cytometer.

Results

Among the examined patients, carotid plaques were detected in 31 (77.5%) participants. The average values of GSM visualized plaques were 58.0 (46.0; 71.5). Atherosclerotic plaques with GSM <50 were detected in 11 (35.5%) patients.

In patients with hypoechoic carotid plaques, the number of CD3+CD56+CD8+CD11b+ cells was statistically significantly higher – 352 (55.0; 505) cells/uL versus 66.0 (15.5; 138) cells/uL in patients with plaques whose GSM values were more than 50 (p=0.020). Based on the results of correlation analysis it was established inverse relationship between number of CD3+CD56+CD8+CD11b+ cells and GSM of plaques (r=−0.427; p=0.016). According to the results of the ROC-analysis, an increase in the number of activated NKT-CD8+ cells over 46.5 cells/uL was a predictor of the presence of hypoechogenic carotid plaques with a sensitivity of 81.8% and a specificity of 45.0% (see Figure 1).

Conclusion

In patients with hypoechoic carotid plaques, the number of CD3+CD56+CD8+CD11b+ cells was significantly higher in comparison with other patients. An increase in the number of activated NKT-CD8+ cells over 46.5 cells/uL was a predictor of the presence of hypoechoic carotid plaques with sensitivity of 81.8% and specificity of 45.0%

Figure 1

Funding Acknowledgement

Type of funding source: None
Empagliflozin impairs smooth muscle cell proliferation, accelerates endothelial regeneration, and prevents neointima formation by altered expression of the vasoactive peptide apelin
Authors: Dutzmann J , Bode L.M , Korte L , Kalies K , Koch S , Tongers J , Bauersachs J , Sedding D.G
Published: November 2020

Background

Empagliflozin, an inhibitor of the sodium glucose co-transporter 2 (SGLT2), developed as an anti-diabetic agent exerts additional beneficial effects on heart failure outcomes in patients with type 2 diabetes mellitus at high cardiovascular risk. However, the effect of empagliflozin on vascular cell function and vascular remodeling processes remain largely elusive.

Methods/Results

Immunocytochemistry and immunoblotting revealed SGLT2 to be expressed in human diabetic and non-diabetic smooth muscle (SMC) and endothelial cells (EC) as well as in murine femoral arteries. In vitro, empagliflozin significantly reduced serum-induced proliferation and migration of human diabetic and non-diabetic SMCs in a dose-dependent manner without any toxic or apoptotic effects. In contrast, empagliflozin significantly increased the cell count and migrational capacity of human diabetic ECs, but not of human non-diabetic ECs. In vivo, therapeutic application of empagliflozin (225 mg/kg medicated diet) resulted in a significantly reduced number of Ki-67+ proliferating neointimal cells in response to femoral artery wire-injury in C57BL/6J mice. Empagliflozin furthermore prevented subsequent neointima formation (luminal stenosis 91.2% vs. 80.6% at 21 days; P<0.05). Comparable effects of empagliflozin were observed in a streptozocin-induced diabetic model of apolipoprotein E−/− mice. Conclusive to the in vitro-results, re-endothelialization was not significantly affected in C57BL/6 mice (non-reendothelialized distance 2.57 mm vs. 2.3 mm; P=0.07), but even significantly improved in diabetic mice after treatment with empagliflozin (3.1 mm vs. 2.58 mm; P<0.001) assessed by Evan's Blue staining 3 days after electric denudation of the murine carotid artery.

Microarray analysis of human SMCs identified the vasoactive peptide apelin to be decisively regulated in response to empagliflozin treatment. Further pathway analysis exhibited apelin to prevent SMC proliferation by de-phosphorylation of Akt and to augment EC proliferation by phosphorylation of p38 MAPK.

Conclusion

These data document the functional impact of empagliflozin on vascular SMCs and ECs for the first time. Empagliflozin significantly reduces serum-induced proliferation and migration of SMCs in vitro and prevented neointima formation in vivo, while augmenting EC proliferation in vitro and re-endothelialization in vivo after vascular injury. Thus, empagliflozin holds promise to exert favorable effects on vascular healing, and to prevent neointima formation following vascular injury in diabetic and non-diabetic patients.

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): Hannover Medical School, Martin-Luther-University Halle-Wittenberg
Empagliflozin and health-related quality of life outcomes in patients with heart failure with reduced ejection fraction: the EMPEROR-Reduced trial
Authors: Butler Javed , Anker Stefan D , Filippatos Gerasimos , Khan Muhammad Shahzeb , Ferreira João Pedro , Pocock Stuart J , Giannetti Nadia , Januzzi James L , Piña Ileana L , Lam Carolyn S P , Ponikowski Piotr , Sattar Naveed , Verma Subodh , Brueckmann Martina , Jamal Waheed , Vedin Ola , Peil Barbara , Zeller Cordula , Zannad Faiez , Packer Milton ,   the EMPEROR-Reduced Trial Committees and Investigators
Published: November 2020

Aims

In this secondary analysis of the EMPEROR-Reduced trial, we sought to evaluate whether the benefits of empagliflozin varied by baseline health status and how empagliflozin impacted patient-reported outcomes in patients with heart failure with reduced ejection fraction.

Methods and results

Health status was assessed by the Kansas City Cardiomyopathy Questionnaires-clinical summary score (KCCQ-CSS). The influence of baseline KCCQ-CSS (analyzed by tertiles) on the effect of empagliflozin on major outcomes was examined using Cox proportional hazards models. Responder analyses were performed to assess the odds of improvement and deterioration in KCCQ scores related to treatment with empagliflozin. Empagliflozin reduced the primary outcome of cardiovascular death or heart failure hospitalization regardless of baseline KCCQ-CSS tertiles [hazard ratio (HR) 0.83 (0.68–1.02), HR 0.74 (0.58–0.94), and HR 0.61 (0.46–0.82) for <62.5, 62.6–85.4, and ≥85.4 score tertiles, respectively; P-trend = 0.10]. Empagliflozin improved KCCQ-CSS, total symptom score, and overall summary score at 3, 8, and 12 months. More patients on empagliflozin had ≥5-point [odds ratio (OR) 1.20 (1.05–1.37)], 10-point [OR 1.26 (1.10–1.44)], and 15-point [OR 1.29 (1.12–1.48)] improvement and fewer had ≥5-point [OR 0.75 (0.64–0.87)] deterioration in KCCQ-CSS at 3 months. These benefits were sustained at 8 and 12 months and were similar for other KCCQ domains.

Conclusion

Empagliflozin improved cardiovascular death or heart failure hospitalization risk across the range of baseline health status. Empagliflozin improved health status across various domains, and this benefit was sustained during long-term follow-up.

Clinical trial registration

URL: https://www.clinicaltrials.gov. Unique identifier: NCT03057977.
Post-natal developmental changes in the composition of the rat neocortical N-glycome
Authors: Klarić Thomas S , Salopek Matija , Micek Vedran , Gornik Kljaić Olga , Lauc Gordan
Published: November 2020

Asparagine-linked glycosylation (N-glycosylation) plays a key role in many neurodevelopmental processes, including neural cell adhesion, neurite outgrowth and axon targeting. However, little is known about the dynamics of N-glycosylation during brain development and, in particular, how the N-glycome of the developing neocortex differs from that of the adult. The aim of this study, therefore, was to perform a thorough characterization of N-glycosylation in both the adult and neonatal rat neocortex in order to gain insights into the types of changes occurring in the N-glycome during neurodevelopment. To this end, we used hydrophilic interaction ultraperformance liquid chromatography coupled to electrospray ionization quadrupole time-of-flight mass spectrometry to compare the adult neocortical N-glycome with that of 24- and 48-h neonates. We report that the abundance of complex N-glycans is significantly lower in adults compared with neonates. Furthermore, the proportion of charged complex N-glycans is also greatly reduced. This decrease in the abundance of complex N-glycans is offset by a corresponding increase in the proportion of truncated and, to a lesser extent, hybrid N-glycans. Lastly, we report that although the proportion of oligomannose N-glycans remains constant at around 24%, the distribution of high-mannose subtypes shifts from predominantly large subtypes in neonates to smaller subtypes in the adult. In summary, our findings indicate that N-glycan synthesis in the rat neocortex is fundamentally different in neonates compared with adults with a general shift occurring from large, sialylated N-glycans towards smaller, neutral structures as neonates develop into adults, coupled with a parallel shift towards smaller oligomannose structures.
Transient establishment of imprinted DNA methylation of transgenic human IC1 sequence in mouse during the preimplantation period
Authors: Hirakawa Katsuhiko , Matsuzaki Hitomi , Tanimoto Keiji
Published: November 2020

Monoallelic gene expression at the Igf2/H19 locus is controlled by paternal allele-specific DNA methylation of the imprinting control region (H19 ICR) that is established during spermatogenesis. We demonstrated that the H19 ICR fragment in transgenic mice acquires allele-specific methylation only after fertilization, which is essential for maintaining its allelic methylation during early embryogenesis. We identified a DNA element required for establishing postfertilization methylation within a 118 bp (m118) region. A previously generated knock-in mouse whose endogenous H19 ICR was substituted with the human H19 ICR (hIC1; 4.8 kb) sequence revealed that the hIC1 sequence was partially methylated in sperm, although this methylation was lost by the blastocyst stage, which we assume is due to a lack of an m118-equivalent sequence in the hIC1 transgene.

To identify a cis sequence involved in postfertilization methylation within the hIC1 region, we generated three transgenic mouse lines (TgM): one carrying an 8.8 kb hIC1 sequence joined to m118 (hIC1+m118), one with the 8.8 kb hIC1 and one with the 5.8 kb hIC1 sequence joined to m118 (hIC1–3′+m118). We found that the hIC1–3′ region was resistant to de novo DNA methylation throughout development. In contrast, the 5′ portion of the hIC1 (hIC1–5′) in both hIC1+m118 and hIC1 TgM were preferentially methylated on the paternal allele only during preimplantation. As DNA methylation levels were higher in hIC1+m118, the m118 sequence could also induce imprinted methylation of the human sequence. Most importantly, the hIC1–5′ sequence appears to possess an activity equivalent to that of m118.
Energy and exergy analyses of PV, solar thermal and photovoltaic/thermal systems: a comparison study
Authors: Qingyang Jiang , Jichun Yang , Yanying Zeng , Huide Fu
Published: November 2020

Compared with photovoltaic (PV) or solar thermal (ST) system alone, the hybrid photovoltaic/thermal (PV/T) system has many advantages such as simultaneous production of electrical and thermal energies, efficient utilization on solar energy, space reduction and so on. However, there is limited data on both the energy and exergy performance comparisons of these three solar systems, especially for annual performance data. This paper aims to present a comparative study on the performances of the PV, ST and PV/T systems by a series of full-day experiments. Energy and exergy performances of these three solar utilization systems were all calculated and analyzed. Moreover, two typical evaluation methods, i.e. semi-empirical system efficiency model method and input–output method, were also used for evaluating the performances of these systems. Finally, based on the input–output method, the annual performances of the PV, ST and PV/T systems under typical meteorological conditions of Hong Kong region were predicted. The results show that the ST system has the highest total energy gain and energy efficiency and the PV system has the highest total exergy gain and exergy efficiency of these three systems. However, by a comprehensive consideration on the energy and exergy performances, the PV/T system has the best overall performance of these three solar systems.
Sharp Estimates for Blowing Down Functions in a Denjoy–Carleman Class
Authors: Belotto da Silva André , Bierstone Edward , Kiro Avner
Published: November 2020

If $F$ is a $C^{\infty }$ function whose composition $F \circ \sigma $ with a blowing-up ${\sigma }$ belongs to a Denjoy–Carleman class $C_M$, then $F$, in general, belongs to a larger class $C_{M^{(2)}}$; that is, there is a loss of regularity. We show that this loss of regularity is sharp. In particular, the loss of regularity of Denjoy–Carleman classes is intrinsic to arguments involving resolution of singularities.
The Search for an HIV Cure: Where Do We Go From Here?
Authors: Li Jonathan Z , Gandhi Rajesh T
Published: November 2020

Since the first case of an HIV sterilizing cure was published, remarkable progress has been made in our understanding of the mechanisms behind HIV persistence. However, our goal of achieving a safe and broadly-available treatment for sustained HIV remission has proven elusive. In this supplement, we provide a series of articles reviewing the technical hurdles facing the field, key assays to measure HIV persistence and the next-generation of therapeutics for HIV remission.
Serum Protein Profiling Reveals a Specific Upregulation of the Immunomodulatory Protein Progranulin in Coronavirus Disease 2019
Authors: Rieder Marina , Wirth Luisa , Pollmeier Luisa , Jeserich Maren , Goller Isabella , Baldus Niklas , Schmid Bonaventura , Busch Hans-Joerg , Hofmann Maike , Thimme Robert , Rieg Siegbert , Kern Winfried , Bode Christoph , Duerschmied Daniel , Lother Achim
Published: November 2020

Background

Severe courses of coronavirus disease 2019 (COVID-19) are associated with elevated levels of interleukin 6 (IL-6). However, there is a growing body of evidence pointing to a broad and more complex disorder of proinflammatory and antiviral responses with disturbed interferon signaling in COVID-19.

Methods

In this prospective, single-center registry, we included severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)–positive patients and patients with similar symptoms and severity of disease but negative for SARS-CoV-2 admitted to the emergency department and compared their serum protein expression profiles.

Results

IL-6 abundance was similar in SARS-CoV-2–positive patients (n = 24) compared with SARS-CoV-2–negative controls (n = 61). In contrast, we observed a specific upregulation of the immunomodulatory protein progranulin (GRN). High GRN abundance was associated with adverse outcomes and increased expression of IL-6 in COVID-19.

Conclusions

The data from this registry reveal that GRN is specifically upregulated in SARS-CoV-2–positive patients while IL-6 may serve as marker for disease severity. The potential of GRN as a biomarker and a possible impact of increased GRN expression on interferon signaling, virus elimination, and virus-induced lung tissue damage in COVID-19 should be further explored.
Provocation as Agentic Practice: Gender Performativity in Online Strategies of Transgender Sex Workers
Authors: Chib Arul , Nguyen Hoan , Lin Daoyi
Published: November 2020

Fluid performances of gender online by gender-diverse individuals facing discrimination and fetishization raises questions about whether these acts are a source of empowerment or reinforce prevailing prejudice. We combine virtual ethnography and interviews with transwomen sex workers in Singapore (n = 14) to explore the dynamic between sociostructural oppression and agentic resistance. First, heterosexual power relations manifest online via digital practices of access, surveillance, and intervention to discriminate against and objectify respondents’ identities and bodies. Second, the online response can be categorized into specific digital practices of avoidance involving privacy and anonymity, accommodation via subtle practices of submission, and collaboration via community mobilization. Finally, gender performativity on sites for sex solicitation manifests in the presentation of both essentialist (submissive femininity) and provocative (hyper-sexual) embodiments, defying simplistic characterization into the structure-agency dynamic. We discuss the co-constructive nature of socially situated gender performances and the potential for challenging normative regimes of gender.
Plant size, environmental factors and functional traits jointly shape the stem radius growth rate in an evergreen coniferous species across ontogenetic stages
Authors: Liu Zhili , Hikosaka Kouki , Li Fengri , Zhu Liangjun , Jin Guangze
Published: November 2020

Aims

Plant size, environmental conditions and functional traits are important for plant growth; however, it is less clear which combination of these factors is the most effective for predicting tree growth across ontogenetic stages.

Methods

We selected 65 individuals of an evergreen coniferous species, Pinus koraiensis, with diameters at breast height (DBH) from 0.3 to 100 cm in Northeast China. For each individual, we measured the stem radius growth rate (SRGR, µm/year) for the current year, environmental factors (light, soil nutrient and soil water) and functional traits (leaf, branch and root traits).

Important Findings

SRGR increased with DBH when the DBH was lower than 58 cm, whereas it decreased with DBH when the DBH was larger than 58 cm. Structural equation modeling analysis suggested that, when the DBH was 0–15 cm, plant size had a direct negative influence on SRGR and an indirect positive influence on SRGR due to the light intensity above the plant. Plant size had direct positive and negative effects when the DBH was 16–58 cm and 59–100 cm, respectively. When the DBH was larger than 15 cm, soil parameters were more important than light intensity for SRGR. The functional traits selected for use in the best model were changed from the specific leaf area and wood density to the root nitrogen concentration with increasing tree size. In summary, plant size, environmental factors and functional traits jointly shaped tree growth, and their relative influence varied with size, suggesting that the resources limiting tree growth may change from light to soil nutrient with increasing tree size.
Dengue, chikungunya and Zika in GeoSentinel surveillance of international travellers: a literature review from 1995 to 2020
Authors: Osman S , Preet R
Published: November 2020

Introduction

GeoSentinel is a global surveillance network of travel medicine providers seeing ill-returned travellers. Much of our knowledge on health problems and infectious encountered by international travellers has evolved as a result of GeoSentinel surveillance, providing geographic and temporal trends in morbidity among travellers while contributing to improved pre-travel advice. We set out to synthesize epidemiological information, clinical manifestations and time trends for dengue, chikungunya and Zika in travellers as captured by GeoSentinel.

Methods

We conducted a systematic literature search in PubMed on international travellers who presented with dengue, chikungunya or Zika virus infections to GeoSentinel sites around the world from 1995 until 2020.

Results

Of 107 GeoSentinel publications, 42 articles were related to dengue, chikungunya and/or Zika. The final analyses and synthesis of and results presented here are based on the findings from 27 original articles covering the three arboviral diseases.

Conclusions

Dengue is the most frequent arboviral disease encountered in travellers presenting to GeoSentinel sites, with increasing trends over the past two decades. In Southeast Asia, annual proportionate morbidity increased from 50 dengue cases per 1000 ill returned travellers in non-epidemic years to an average of 159 cases per 1000 travellers during epidemic years. The highest number of travellers with chikungunya virus infections was reported during the chikungunya outbreak in the Americas and the Caribbean in the years 2013–16. Zika was first reported by GeoSentinel already in 2012, but notifications peaked in the years 2016–17 reflecting the public health emergency in the Americas at the time.
Spatial variability in carbon- and nitrogen-related traits in apple trees: the effects of the light environment and crop load
Authors: Ngao Jérôme , Martinez Sébastien , Marquier André , Bluy Sylvie , Saint-Joanis Brigitte , Costes Evelyne , Pallas Benoît
Published: November 2020

Photosynthetic carbon assimilation rates are highly dependent on environmental factors such as light availability and on metabolic limitations such as the demand for carbon by sink organs. The relative effects of light and sink demand on photosynthesis in perennial plants such as trees remain poorly characterized. The aim of the present study was therefore to characterize the relationships between light and fruit load on a range of leaf traits including photosynthesis, non-structural carbohydrate content, leaf structure, and nitrogen-related variables in fruiting (‘ON’) and non-fruiting (‘OFF’) ‘Golden Delicious’ apple trees. We show that crop status (at the tree scale) exerts a greater influence over leaf traits than the local light environment or the local fruit load. High rates of photosynthesis were observed in the ON trees. This was correlated with a high leaf nitrogen content. In contrast, little spatial variability in photosynthesis rates was observed in the OFF trees. The lack of variation in photosynthesis rates was associated with high leaf non-structural carbohydrate content at the tree level. Taken together, these results suggest that low carbon demand leads to feedback limitation on photosynthesis resulting in a low level of within-tree variability. These findings provide new insights into carbon and nitrogen allocations within trees, which are heavily dependent on carbon demand.
Which Came First, the Demandes d’amours or the Jeu-Parti? Evidence from Oxford, Bodleian Library, MS Douce 308
Authors: Leach Elizabeth Eva
Published: November 2020

The relationship between the two genres of demandes d’amours and jeux-partis, the first a short-form exchange in prose, the other an extended debate in sung poetry, has been argued to be that of informal oral model to later formal written art form. The origins of the jeu-parti are presumed to be found in the tradition of demandes. By considering the earliest written collection of demandes, however—that found in the manuscript Bodleian Library, Douce 308, where they occur within a collection of jeux-partis—this origin story is subjected to renewed scrutiny.
PED in 2021: a major update of the protein ensemble database for intrinsically disordered proteins
Authors: Lazar Tamas , Martínez-Pérez Elizabeth , Quaglia Federica , Hatos András , Chemes Lucía B , Iserte Javier A , Méndez Nicolás A , Garrone Nicolás A , Saldaño Tadeo E , Marchetti Julia , Rueda Ana Julia Velez , Bernadó Pau , Blackledge Martin , Cordeiro Tiago N , Fagerberg Eric , Forman-Kay Julie D , Fornasari Maria S , Gibson Toby J , Gomes Gregory-Neal W , Gradinaru Claudiu C , Head-Gordon Teresa , Jensen Malene Ringkjøbing , Lemke Edward A , Longhi Sonia , Marino-Buslje Cristina , Minervini Giovanni , Mittag Tanja , Monzon Alexander Miguel , Pappu Rohit V , Parisi Gustavo , Ricard-Blum Sylvie , Ruff Kiersten M , Salladini Edoardo , Skepö Marie , Svergun Dmitri , Vallet Sylvain D , Varadi Mihaly , Tompa Peter , Tosatto Silvio C E , Piovesan Damiano
Published: November 2020

The Protein Ensemble Database (PED) (https://proteinensemble.org), which holds structural ensembles of intrinsically disordered proteins (IDPs), has been significantly updated and upgraded since its last release in 2016. The new version, PED 4.0, has been completely redesigned and reimplemented with cutting-edge technology and now holds about six times more data (162 versus 24 entries and 242 versus 60 structural ensembles) and a broader representation of state of the art ensemble generation methods than the previous version. The database has a completely renewed graphical interface with an interactive feature viewer for region-based annotations, and provides a series of descriptors of the qualitative and quantitative properties of the ensembles. High quality of the data is guaranteed by a new submission process, which combines both automatic and manual evaluation steps. A team of biocurators integrate structured metadata describing the ensemble generation methodology, experimental constraints and conditions. A new search engine allows the user to build advanced queries and search all entry fields including cross-references to IDP-related resources such as DisProt, MobiDB, BMRB and SASBDB. We expect that the renewed PED will be useful for researchers interested in the atomic-level understanding of IDP function, and promote the rational, structure-based design of IDP-targeting drugs.
Nestin+/CD31+ cells in the hypoxic perivascular niche regulate glioblastoma chemoresistance by upregulating JAG1 and DLL4
Authors: Zheng Zong-Qing , Chen Jin-Tao , Zheng Ming-Cheng , Yang Li-Juan , Wang Jun-Ming , Liu Quan-Li , Chen Lu-Fei , Ye Zu-Cheng , Lin Jin-Ming , Lin Zhi-Xiong
Published: November 2020

Background

Failure of glioblastoma (GBM) therapy is often ascribed to different types of glioblastoma stem-like cell (GSLC) niche; in particular, a hypoxic perivascular niche (HPVN) is involved in GBM progression. However, the cells responsible for HPVNs remain unclear.

Methods

Immunostaining was performed to determine the cells involved in HPVNs. A hypoxic chamber and 3-dimensional (3D) microfluidic chips were designed to simulate a HPVN based on the pathological features of GBM. The phenotype of GSLCs was evaluated by fluorescence scanning in real time and proliferation and apoptotic assays. The expression of JAG1, DLL4, and Hes1 was determined by immunostaining, ELISA, Western blotting, and quantitative PCR. Their clinical prognostic significance in GBM HPVNs and total tumor tissues were verified by clinical data and The Cancer Genome Atlas databases.

Results

Nestin+/CD31+ cells and pericytes constitute the major part of microvessels in the HPVN, and the high ratio of nestin+/CD31+ cells rather than pericytes are responsible for the poor prognosis of GBM. A more real HPVN was simulated by a hypoxic coculture system in vitro, which consisted of 3D microfluidic chips and a hypoxic chamber. Nestin+/CD31+ cells in the HPVN were derived from GSLC transdifferentiation and promoted GSLC chemoresistance by providing more JAG1 and DLL4 to induce downstream Hes1 overexpression. Poor GBM prognosis correlated with Hes1 expression of tumor cells in the GBM HPVN, and not with total Hes1 expression in GBM tissues.

Conclusions

These results highlight the critical role of nestin+/CD31+ cells in HPVNs that acts in GBM chemoresistance and reveal the distinctive prognostic value of these molecular markers in HPVNs.
Cytokine and Chemokine Levels in Coronavirus Disease 2019 Convalescent Plasma
Authors: Bonny Tania S , Patel Eshan U , Zhu Xianming , Bloch Evan M , Grabowski M Kate , Abraham Alison G , Littlefield Kirsten , Shrestha Ruchee , Benner Sarah E , Laeyendecker Oliver , Shoham Shmuel , Sullivan David , Quinn Thomas C , Casadevall Arturo , Pekosz Andrew , Redd Andrew D , Tobian Aaron A R
Published: November 2020

Background

The efficacy of coronavirus disease 2019 (COVID-19) convalescent plasma (CCP) is primarily ascribed as a source of neutralizing anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies. However, the composition of other immune components in CCP and their potential roles remain largely unexplored. This study aimed to describe the composition and concentrations of plasma cytokines and chemokines in eligible CCP donors.

Methods

A cross-sectional study was conducted among 20 prepandemic healthy blood donors without SARS-CoV-2 infection and 140 eligible CCP donors with confirmed SARS-CoV-2 infection. Electrochemiluminescence detection-based multiplexed sandwich immunoassays were used to quantify plasma cytokine and chemokine concentrations (n = 35 analytes). A SARS-CoV-2 microneutralization assay was also performed. Differences in the percentage of detection and distribution of cytokine and chemokine concentrations were examined by categorical groups using Fisher’s exact and Wilcoxon rank-sum tests, respectively.

Results

Among CCP donors (n = 140), the median time since molecular diagnosis of SARS-CoV-2 was 44 days (interquartile range = 38–50) and 9% (n = 12) were hospitalized due to COVID-19. Compared with healthy blood donor controls, CCP donors had significantly higher plasma levels of interferon (IFN)-γ, interleukin (IL)-10, IL-15, IL-21, and macrophage-inflammatory protein-1, but lower levels of IL-1RA, IL-8, IL-16, and vascular endothelial growth factor-A (P < .0014). The distributions of plasma levels of IL-8, IL-15, and IFN-inducible protein-10 were significantly higher among CCP donors with high (≥160) versus low (<40) anti-SARS-CoV-2 neutralizing antibody titers (P < .0014). The median levels of IL-6 were significantly higher among CCP donors who were hospitalized versus nonhospitalized (P < .0014).

Conclusions

Heterogeneity in cytokine and chemokine composition of CCP suggests there is a different inflammatory state among the CCP donors compared with SARS-CoV-2 naive, healthy blood donors.
Buckwheat FeNramp5 Mediates High Manganese Uptake in Roots
Authors: Yokosho Kengo , Yamaji Naoki , Ma Jian Feng
Published: November 2020

Manganese (Mn) is an essential element for plant growth and development, but transporters required for Mn uptake have only been identified in a few plant species. Here, we functionally characterized a member of the natural resistance-associated macrophage proteins (Nramps) family, FeNramp5 in buckwheat (Fagopyrum esculentum Moench), which is known as a species well adapted to acidic soils. FeNramp5 was mainly expressed in the roots, and its expression was upregulated by the deficiency of Mn and Fe. Furthermore, spatial and tissue-specific expression analysis showed that FeNramp5 was expressed in all tissues of the basal root regions. FeNramp5-GFP protein was localized to the plasma membrane when transiently expressed in buckwheat leaf protoplast. FeNramp5 showed the transport activity for Mn2+ and Cd2+ but not for Fe2+ when expressed in yeast. Furthermore, the transport activity for Mn2+ was higher in yeast expressing FeNramp5 than in yeast expressing AtNramp1. FeNramp5 was also able to complement the phenotype of Arabidopsis atnramp1 mutant in terms of the growth and accumulation of Mn and Cd. The absolute expression level of AtNramp1 was comparable to that of FeNramp5 in the roots, but buckwheat accumulated higher Mn than Arabidopsis when grown under the same condition. Further analysis showed that at least motif B in FeNramp5 seems important for its high transport activity for Mn. These results indicate that FeNramp5 is a transporter for the uptake of Mn and Cd and its higher transport activity for Mn is probably associated with higher Mn accumulation in buckwheat.