bluuebunny/crossref_metadata_2025_split huggingface dataset:
Protective Role Of Estrogen Against Excessive Erythrocytosis In Monge’s Disease
Authors: Azad Priti , Patel Gargi , Bermutez Daniella , Villafuerte Francisco , Haddad Gabriel 
Published: April 2020

RationaleChronic mountain sickness (CMS), or Monge’s disease, is an advancing and debilitating syndrome caused by chronic (years) exposure to high altitude hypoxia, as experienced by people living in the Andean region. Excessive erythrocytosis (EE) is one of the critical traits of CMS and this excessive pathobiologic response has deleterious effects since a high hematocrit would increase blood viscosity and reduce blood flow to hypoxia‐sensitive organs (brain and heart), often resulting in myocardial infarction or stroke in young adults. Within the population of Cerro de Pasco in the Andes, CMS prevalence is vastly different between males and females, being rare in females. Of interest is that there is a sharp increase in CMS incidence in females after menopause. This suggests the role of gender and sex hormones in altering disease manifestation.MethodsIn order to understand the molecular basis for polycythemia of high altitude, we have generated a disease in‐the dish‐model by re‐programming fibroblasts and native CD34+ve cells from CMS and non‐CMS subjects and converting them to RBC. Using this in‐vitro platform, we are now studying the interactions between genetic factors and sex hormones (Testosterone, Estrogen and Progesterone) and their effect on RBC production in the CMS and non‐CMS subjects at high altitude.ResultsWhile we found that testosterone increased RBC production somewhat, estrogen in physiologic concentrations (10nM), in sharp contrast, reduced the CD235a (Glycophorin A‐marker of mature RBC) remarkably (from 65.4% in the untreated CMS sample to 11% in the treated CMS) and eliminated the CMS EE phenotype. There was also stage‐specificity since we found that the impact was most severe when estrogen was present at the EB stage. This strongly suggests that estrogen has a protective role against the polycythemia phenotype. To probe further, we studied the effect of estrogen (10nM) on GATA1, a critical link with erythropoiesis. There was a sharp 5 fold decrease in GATA1 (p<0.01) and its target genes such as Alas2 (14 fold, p<0.001) in erythroid cells. This decreased expression resulted in marked reduction (>50%) in RBC production, demonstrating that estrogen constrains RBC production in females.ConclusionOur results demonstrate that estrogen inhibits GATA1 expression and prevents excessive erythropoiesis and Monge’s disease in females at high altitude. We believe that these studies not only shed light on role of sex hormones on hypoxia‐induced excessive erythropoiesis but have a broader application in their regulation of erythropoiesis and related blood disorders.
Complex Dental Structure and Wear Biomechanics in Non‐Avian Dinosaurs and Pleistocene Mammals
Authors: Erickson Gregory , Hunt Tyler , Kuhn-Hendricks Stephen , Pathak Siddhartha , Varma Soumya , Babuska Tomas , Grejtak Tomas , Krick Brandon 
Published: April 2020

Reptiles rarely approached the biomechanical sophistication for feeding or dietary diversity seen in mammals. Their teeth are typically non‐occluding, semi‐conical structures with simplistic parallel‐crystallite enamel surrounding an orthodentine core. Conversely, most mammals possess multi‐cusped teeth that are drawn across one another during mastication and self‐wear to their functional morphology. The most complex dental architectures are seen in herbivorous mammals. Their teeth are composed of up to four constituents (incl. prismatic enamel) that strategically wear creating coarse grinding or slicing surfaces. These allow them to comminute tough and/or abrasive plants and liberate nutrients inaccessible to other animals. Non‐avian dinosaurs stand out among reptiles in that precise, mammal‐like dental occlusion and self‐wearing teeth evolved on at least four occasions. These topographies enabled access to myriad floral types and facilitated their respective ecological diversifications. My research group and colleagues showed that the teeth of these dinosaurs are histologically more complex than formerly appreciated. Using cutting‐edge material science and tribological engineering indentation techniques we discovered that wear and fracture relevant material properties are preserved in the fossil dental tissues of dinosaurs and Pleistocene mammals. This led to development of a 3D Archard’s wear model from which we determined how horse‐like occlusal surfaces for the grinding of plant matter occurred in hadrosaurids, and fuller‐like slicing surfaces developed and functioned in ceratopsians. In current research we are studying how the grinding dentitions of mammoths similarly formed through self‐wear. Notably our paleontologically‐inspired wear model is seeing broad industrial applications.Support or Funding InformationNSF CMMI (Civil, Mechanical and Manufacturing Innovation) Eager and AFOSR (Air Force Office of Scientific Research) to GME, SP and BAK
Modulation of the repetitive element transcriptome by healthy aging interventions
Authors: Wahl Devin , Cavalier Alyssa , LaRocca Thomas 
Published: April 2020

Growing evidence indicates that non‐coding repetitive elements (RE) may play an important role in aging. For example, recent studies have shown that age‐related RE transcript accumulation may cause pro‐inflammatory signaling and be detrimental to cardiometabolic health. However, RE are often ignored in transcriptome studies on aging. Moreover, their role in well‐known healthy aging interventions has not been comprehensively characterized, and the link between RE transcript accumulation and lifespan is unknown. To investigate this, we have analyzed RE transcript expression in multiple RNA‐seq datasets on aging, and in transcriptome data on mice subjected to several of the most robust and well‐studied lifespan increasing interventions, including: calorie restriction (CR), acarbose, Rapamycin, Protandim, and 17‐□ estradiol. We find that aging is associated with a general accumulation of RE transcripts in multiple tissues, but that CR significantly reduces the expression of >60% of RE transcripts in the liver and brain (p<0.05 vs. controls). We also observe that RE transcript levels are modulated significantly by Rapamycin, acarbose, and Protandim. Overlap analyses indicate that certain RE transcripts are affected by multiple interventions, suggesting that these RE may play a particularly important role in aging and healthy aging interventions, and we are investigating correlations among these RE transcripts and transcriptome signatures of adverse aging processes including inflammation. Collectively, our results suggest that the accumulation of RE transcripts may play an important role in aging and represent a novel target for increasing lifespan.Support or Funding InformationR21: AG060302
S‐Palmitoylation Mediates Caveolae Localization and Limits Cysteine Oxidation of GC‐1 in Cardiomyocytes
Authors: Tzimas Christos , Russo Ilaria , Dun Wen , Yilmaz Sevde , Rajan Sudarsan , Tsai Emily J. 
Published: April 2020

IntroductionThe nitric oxide (NO) receptor soluble guanylyl cyclase (GC‐1) was first identified as a cytosolic enzyme but is now known to localize to various cell membrane microdomains. We reported that in normal hearts, GC‐1 localizes to caveolae, where it exhibits enhanced NO‐responsiveness. In failing hearts, caveolae‐localization of GC‐1 is disrupted and GC‐1 outside of caveolae is oxidized. How GC‐1 dynamically localizes to and away from caveolae is unknown. We hypothesized that S‐palmitoylation, a reversible, enzyme‐catalyzed, post‐translational modification that enhances membrane affinity of protein substrates, mediates caveolae‐localization and modulates redox regulation of GC‐1.MethodsTo examine S‐palmitoylation of GC‐1 in the failing heart, we subjected adult male C57BL/6 mice to transverse aortic constriction (TAC) vs thoracotomy (Sham) and performed modified acyl‐biotin exchange (ABE) assays. Expression of palmitoyl‐transferases ZDHHC1, ‐16, and ‐24 were also assessed in mouse hearts at the transcript and protein levels. Using computational bioinformatics, we identified 5 conserved cysteines of potential S‐palmitoylation in the GC‐1α subunit. We created cysteine‐serine mutants of GC‐1α at each and all of the 5 sites (C3S, C15S, C176S, C497S, C595S, CS*). We expressed the mutants and WT GC‐1α in neonatal rat cardiomyocytes (NRCM) via adenoviral mediated gene transfer and compared their palmitoylation status by ABE. We also assessed caveolae‐localization of GC‐1α (CS* vs WT) by confocal microscopy and its oxidation by redox Western.ResultsIn TAC hearts, S‐palmitoylation of GC‐1α was diminished by 50% compared to Sham (p=0.02). Likewise, ZDHHC16 was also downregulated in TAC by 31% (p=0.01) at the transcript level and by 56% (p=0.03) at the protein level, relative to Sham. In NRCMs, S‐palmitoylation of CS* was profoundly diminished (6.9±2.0 % of WT, p<0.001), while that of C15S, C176S, and C497S were each modestly diminished (23.8±8.4%, p=0.03; 23.2±6.6%, p=0.01; 22.8±6.0%, p=0.01, respectively of WT). S‐palmitoylation of C3S and C595S were similar to WT. Confocal microscopy of NRCMs revealed more diffuse cytosolic distribution of CS* compared to WT. Redox Westerns revealed a trend towards increased cysteine oxidation of CS* vs WT upon H2O2 treatment (1.5‐fold increase, p=0.05).ConclusionsOur data suggest that S‐palmitoylation of GC‐1α at C15, C176, and C497 mediates GC‐1 caveolae‐localization and may reciprocally regulate cysteine post‐translational modifications of GC‐1.Support or Funding Information5R01HL138528 to EJT.
Securinine protects vascular dysfunction targeting atherosclerosis in vascular endothelial cells, smooth muscle cells, and apolipoprotein E deficient mice
Authors: Lee Yun Jung , Yoon Jung Joo , Han Byung Hyuk , Lee Hyeon Kyoung , Yang Sun Ryo , Lee Ho Sub , Kang Dae Gill 
Published: April 2020

Atherosclerosis is a chronic vascular disease and characterized by accumulation within the intima of inflammatory cells, smooth muscle cells, lipid, and connective tissue. Here, we suggest securinine as an anti‐atherosclerotic agent to attenuate vascular dysfunction and lesion. To identify natural agents that commonly reverse advanced atherosclerotic plaque to early atherosclerotic plaque, significantly regulated genes were analyzed in silico. The differentially expressed genes from 9 intimal thickening and 8 fibrous cap atheroma tissue which were collected from GEO data were assessed by the connectivity map. Natural candidate securinine, a main compound from Securinega suffruticosa, was selected and administrated 1, 5 mg/kg/day in apolipoprotein‐E‐deficient (ApoE KO) mice for 18 weeks. Securinine significantly showed lowered blood pressure and improvement of metabolic parameters with hyperlipidemia. The impairment in vasorelaxation was remarkably decreased by treatment with securinine. H&E staining revealed that treatment with securinine reduced atherosclerotic lesions. Securinine suppressed the expression of adhesion molecules and matrix metalloproteinase‐2/‐9 in both ApoE KO and vascular endothelial cells (HUVEC). In HUVEC pretreatment with securinine significantly inhibited ROS generation and NF‐κB activation. Growth curve assays using the real‐time cell analyzer showed that securinine significantly decreased TNF‐α‐induced aortic smooth muscle cell proliferation and migration in a dose‐dependent manner. Thus securinine may be a potential natural candidate for the treatment of atherosclerosis because it attenuates vascular inflammation and dysfunction as well as vascular lesion.Support or Funding InformationThis work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (2017R1A5A2015805)(2017R1D1A3B03029089) (2019R1A2C1085650).
Effect of Histamine‐receptor Antagonism on VO2Peak Improvements to Exercise Training
Authors: Sieck Dylan Charles , Mangum Joshua E. , Ely Matthew R. , Francisco Mike E. , Larson Emily A. , Kaiser Brendan W. , Minson Christopher T. , Halliwill John R. 
Published: April 2020

One of the physiological changes following moderate intensity aerobic exercise is a transient reduction in blood pressure, termed post‐exercise hypotension (PEH), which is exercise intensity and duration dependent. This short‐term reduction in blood pressure is dependent upon skeletal muscle histamine production and release, which causes increased conductance via local activation of histamine H1 and H2 receptors. PEH is abolished when antihistamines are consumed prior to exercise. Additionally, histamine‐receptor antagonism during a single bout of exercise modifies expression of the transcriptome related to inflammation, angiogenesis, and metabolism. Due to the large role histamine plays in post‐exercise recovery, the scope of histamine receptor activation in adaptations to aerobic exercise training needs to be determined. Therefore, the purpose of this study was to examine histamine’s role in promoting adaptation to exercise. It is hypothesized that blocking histamine’s actions will attenuate adaptations that occur from aerobic exercise training. 16 young, healthy, recreationally active individuals (5M, 11F) volunteered for this study. All volunteers completed 6 weeks of exercise training (3–4 times a week), for a total of 21 exercise sessions. Exercise training combined 18 sessions of continuous exercise (1 hour at 60% VO2peak) and 3 sessions of high intensity interval training (30 min between 30 and 90% VO2peak). Volunteers were randomly placed into a placebo or histamine antagonism (540 mg fexofenadine; a H1‐receptor antagonist, and 300 mg of ranitidine; a H2‐receptor antagonist) group, and consumed medication 1 hour prior to each exercise session. Data was collected 4 times throughout the study with pre and post exercise training measures, as well as after every 2 weeks of exercise training. Measurements of VO2peak and cycle ergometry work rate were obtained. Exercise training resulted in increased absolute VO2peak of all subjects (9.4±1.5%; P<0.01); however, no difference was seen between groups (10.9±1.8% control vs 7.9±2.4% blockade; P=0.35). Additionally, exercise training resulted in increased cycle ergometry work rate of all subjects (11.2±1.6%; P<0.01); however, there was a trend for blunted improvement with blockade (7.7±2.4%) vs control (14.6±2.8%; P=0.08). In conclusion, blocking histamine’s actions had no effect on VO2 adaptations to exercise training. Additional information about factors related to O2 delivery and consumption are needed to understand the relationship between histamine and cardiovascular adaptation to exercise training.Support or Funding InformationSupport provided by: The Eugene & Clarissa Evonuk Memorial Graduate Fellowship
High‐intensity interval training decreases muscle sympathetic nerve activity and improves peripheral vascular function in patients with heart failure with reduced ejection fraction
Authors: Sales Allan Kluser , Azevedo Luciene F. , Oliveira Thiago O. , Nunes Alves Maria Janieire N. , Rodrigues Amanda G. , Oliveira Patricia A. , Jordao Camila P. , Andrade Ana , Urias Ursula , Guimaraes Guilherme V. , Bocchi Edimar A. , Grunewald Zachary I. , Martinez-Lemus Luis A. , Padilla Jaume , Negrao Carlos Eduardo 
Published: April 2020

BackgroundModerate intensity continuous exercise (MICT) has been shown to reduce muscle sympathetic nerve activity (MSNA) in heart failure patients with reduced ejection fraction (HFrEF). However, the effects of high‐intensity interval training (HIIT) on MSNA in HFrEF patients are unknown. We hypothesized that reductions in MSNA would be greater following HIIT than MICT and correspond with improvements in peripheral vascular function.MethodsHFrEF patients (30 ‐ 65 years), left ventricular ejection fraction ≤ 40%, Functional Classes II–III, were randomized into HIIT, MICT or no training (NT) three times/week for 12 weeks. MSNA was assessed by microneurography. Brachial artery flow‐mediated dilation (FMD), blood flow and vascular conductance were assessed by ultrasonography, blood pressure (BP) and heart rate (HR) by plethysmography and peak oxygen uptake (V̇O2peak) by a cardiopulmonary exercise test.ResultsBoth, HIIT and MICT, led to reductions in MSNA (frequency and incidence burst) relative to NT (p<0.05). However, the reduction in MSNA was more pronounced following HIIT than MICT (p<0.05). Increases in brachial artery FMD, resting blood flow and conductance were also greater following HIIT than MICT (p<0.05), while V̇O2peak increased similarly following HIIT and MICT relative to NT. No changes in BP or HR were observed in either exercise condition. Further analysis showed a negative correlation between changes in MSNA and FMD following the interventions (r=−0.60, p=0.005).ConclusionOur findings indicate that 12 weeks of HIIT is superior to MICT in reducing sympathetic overactivity and improving vascular function in patients with HFrEF, despite similar increases in exercise capacity.Support or Funding InformationFAPESP Grants (2014/11671‐6 and 2017/25613‐6)
Sensitive and Comprehensive Lipid Mediator Analysis using Advanced Scheduled MRM with Polarity Switching and QTRAP Enhanced Product Ion Scanning
Authors: Norris Paul , Pearson Mackenzie Jo , Kapil Santosh , Ubhi Baljit 
Published: April 2020

Using a QTRAP® 6500+ system coupled with an ExionLC™ System, we developed a targeted panel of 88 compounds for comprehensive profiling of lipid mediators and pathway markers. A Kinetex® Polar C18 column was used for LC based separation of lipid mediators, epimers and other isoelemental structures within a 20 min run time. Advanced scheduled sMRM was used to optimize scanning windows and dwell weighting. The negative mode lipid mediator panel includes pro‐inflammatory prostaglandins, leukotrienes and their primary metabolites, specialized pro‐resolving mediators (SPM) including resolvins, protectins, maresins, and lipoxins, biomarkers of ROS and NOS, and fatty acid and mono‐hydroxy fatty acid precursors. The positive mode panel includes cysteinyl leukotrienes, PAF, and maresin and protectin conjugates in tissue regeneration (MCTRs and PCTRs).Concentration curves were generated by injecting 3 replicate injections of 8 different concentrations of each lipid mediator standard. Excellent linearity is observed with r2 of at least 0.997 for all analytes. Excellent sensitivity was obtained for all lipid mediator species with LLOQ between 0.05 and 1 ng/mL and CV < 30%. The unique qualitative/quantitative QTRAP platform also enabled MRM triggered EPI experiments which provided high sensitivity MS/MS data for confirmation of low level analytes. Baseline separation of LXA4 and 15‐epi‐LXA4 well as RvD1 and 17‐epi‐RvD1 enables the differentiation of enzymatic pathway utilization for pro‐resolving lipid mediator production.
MS/MSALL with SelexION®: A High‐throughput Lipidomic Solution for Untargeted Profiling
Authors: Pearson Mackenzie Jo , Kapil Santosh , Norris Paul , Ubhi Baljit , Dumlao Darren 
Published: April 2020

Global lipid profiling is a growing area of interest and is a primary means to measure the changes in lipid molecular species as a function of human disease or drug treatment. One of the most challenging aspects of lipid analysis by mass spectrometry is isobaric overlap, or molecules having the same or nearly the same mass. With direct infusion, or ‘Shotgun’ approaches, the user is able to rapidly profile biological samples. On the Sciex 6600+ TripleTOF®, the MSMSALL method on this system generates data by collecting product ions of all precursor masses. Using this approach, thousands of lipids can be represented in a profile snapshot and allows for retrospective analysis of acquired data. However the issue of isobaric overlap is not addressed.Isobaric overlap is a complex problem in lipidomic workflows and can make positive identification or quantification of a lipid species very difficult. The issue of isobaric overlap is often approached with liquid chromatography separation. However, lengthy sample preparation, method development, and lengthy chromatographic run times for adequate separation can narrow the scope of the lipidome and diminish throughput. Differential ion mobility separation (DMS) is a relatively new ion mobility technology that uses a molecule’s dipole moment to isolate it rather than shape and size. The SelexION® device is installed at atmosphere, so the addition of chemical modifiers can be applied to the system to assist in additional separation. In this study, 1‐propanol is used as the chemical modifier to separate the six phospholipid subclasses while cardiolipin’s ‐2H charge state is used to separate this class without the assistance of chemical modifier. Unique compensation voltages are then found with standards and assigned to each lipid class to ensure lipid class isolation. In negative ion mode, all seven classes can be acquired in just under twelve minutes of total run time. This allows for untargeted, high‐throughput acquisition of the lipidome while simultaneously acquiring MS/MS spectra for lipid species identification.LipidView software is used to analyze the data collected from the SelexION® runs in a high throughput fashion. All samples from each class can be loaded and a lipid class can be assigned along with its corresponding COV. Since much of the isobaric overlap has been removed from the sample a positive identification and quantification can be made.
A surface‐exposed, network substitution results in a gain‐of‐function in tryptophan synthase6.5.0
Authors: D’Amico Rebecca N. , O’Rourke Kathleen F. , Bosken Yuliana , Murray Alec M. , Chang Chia-en A. , Boehr David D. 
Published: April 2020

Tryptophan synthase (TS) is a α2β2 dimeric enzyme that catalyzes the final two reactions in the production of tryptophan. The product of the alpha subunit (αTS), indole, is channeled to the beta subunit (βTS) where it is then condensed with serine to form tryptophan. TS is a valuable model system for understanding enzyme allostery, and specifically enzyme‐enzyme communication. We previously identified amino acid interaction networks in αTS using NMR‐based methods. We proposed that these network residues play an important role in catalysis and communication between the two subunits. Based on previous studies, αTS residue Ala198 was identified as a residue of interest. Ala198 is a surface‐exposed, network residue that is dynamic on the ms‐μs timescale, according to our previous NMR studies. To better understand the networks, we characterized the A198W variant by performing cell‐based assays, kinetic assays, molecular dynamics (MD) simulations, and NMR experiments. We found that E.coli cells expressing the A198W variant had a faster growth rate in minimal medium compared to cells expressing the wild‐type αTS. Our kinetic studies on purified TS indicated that the A198W variant had little effect on αTS activity, but increased the activity of the TS complex (i.e. from initial indole‐3‐glycerol phosphate substrate to final tryptophan product), perhaps due to an enhancement of indole channeling. MD simulations indicated that the A198W substitution led to structural dynamic changes that propagated throughout αTS, including several key residues at the α/β binding interface. The MD simulations were consistent with the indole channel being more open, more often, which could help explain the increase in TS activity in vitro and in vivo. NMR experiments also indicated that the A198W substitution induced structural dynamic changes throughout αTS, consistent with the MD simulations. Despite Ala198 being distal from both the active site of αTS (27Å) and the α/β binding interface (30Å), substitutions at this position result in changes to catalytic efficiency and the TS complex dynamics. These findings underscore the importance of network residues on enzyme dynamics, allostery, and subunit communication. Engineering of surface‐exposed network residues represents one way of controlling enzyme activity.6.5.0Support or Funding Information6.5.06.5.0