bluuebunny/crossref_metadata_2025 huggingface dataset:
Contrasting Reflex Neural Modulation of Muscle Sympathetic Nerve Activity at Rest and During One‐leg Dynamic Exercise in Subjects with and without Heart Failure
Authors: Notarius Catherine F. , Keir Daniel A. , Badrov Mark B. , Millar Philip J. , Oh Paul , Floras John S.
Published: April 2020

We previously showed that muscle sympathetic nerve activity (MSNA) is augmented at rest in patients with heart failure due to reduced ejection fraction (HFrEF), and rises further during mild and moderate dynamic 1‐leg exercise in stark contrast to the drop observed in healthy controls at similar exercise intensities. The reflex mechanisms responsible for this unique response are unknown. We hypothesized that MSNA may be reduced at rest and during exercise in HFrEF by either: 1) stimulating the sympatho‐inhibitory cardiopulmonary baroreceptors by exercising supine rather than upright; or 2) inhibiting the sympatho‐excitatory peripheral chemoreceptors by breathing 32% oxygen (O2). We studied 6 stable, non‐diabetic, medicated HFrEF men ( mean age 58 ± 3 SE [range 46 to 65] years; mean left ventricular ejection fraction 29 ± 4% [range 15–38]); of either ischemic (n=5) or non‐ischemic (n=1) etiology; plus 6 healthy, age matched, medication‐free volunteers (3 women; mean age 58 ± 3 [range 49 to 72]). We assessed peak oxygen uptake (VO2peak ) by open‐circuit spirometry. On a separate day, fibular MSNA (microneurography) was measured at rest and during upright 1‐leg cycling (2 min each unloaded and at 50% of VO2peak). The identical cycling protocol was then repeated during supine exercise (n=5 HFrEF) and again during upright cycling while breathing 32% O2 (n=4 HFrEF). Heart rate and diastolic blood pressure were similar across interventions in both groups but systolic blood pressure was significantly lower in HFrEF vs controls (main effect P=0.01). MSNA was reduced at rest only while supine in control subjects (main effect P=0.01; P=0.01 vs upright). Whereas in HFrEF, both supine posture and supplemental O2 attenuated MSNA burst frequency at rest (main effect P=0.01; P=0.02 vs upright). During exercise, MSNA burst frequency progressively decreased in healthy controls particularly during unloaded cycling (main effect of time P<0.001), and tended to be lower throughout supine cycling (P=0.06 vs upright). By contrast, in HFrEF patients, there was no significant change in MSNA burst frequency during exercise while supine nor with supplemental oxygen (main effect of intervention P=0.51; time P=0.34). Thus, both at rest and during mild cycling exercise, supine posture augments the sympathoinhibitory response in control subjects. However in HFrEF patients, sympathoexcitation at rest can be reduced to a similar extent by either triggering the inhibitory cardiopulmonary baroreflex or abolishing arterial chemoreceptor activation with no further effect during exercise.

Support or Funding Information

Supported by Heart and Stroke Foundation of Ontario and Canadian Institutes for Health Research
The Effects of Time Restricted Feeding and Exercise on Performance and Body Composition in Healthy Mice
Authors: Persinger Aaron , Butawan Matthew , Pryke Ashley , Rose Kyley , Faietti Martina , van der Merwe Marie , Bloomer Richard , Puppa Melissa
Published: April 2020

Intermittent fasting refers to a period of unregulated caloric consumption paired with a period of complete, or heavily restricted, caloric consumption. One version of this involves splitting the day into a consumption period and a restricted period, known as time‐restricted feeding (TRF). TRF is shown to improve metabolic health and positively affect mitochondria, independent of weight loss. Aerobic exercise is also shown to improve these parameters; however, the combination of intermittent fasting and aerobic exercise in a healthy system has not been examined. The purpose of this study was to examine the effects of the feeding window time in relation to exercise on body weight, body fat percentage, lean mass, and run to exhaustion. Healthy, young mice were placed in one of three groups: ad libitum control group (CON), 18‐hour fasting with a 6‐hour feeding starting immediately post exercise (IM), and 18‐hour fasting with a 6 hour feeding starting 5 hours post exercise (DG). The mice ran 5 days a week, 1 hour a day, for a total of 8 weeks at the beginning of the dark cycle. A run to exhaustion (RTE) was conducted at week 0 and week 8 of the study. Mice were weighed twice weekly and underwent an MRI once a week. Data are presented as mean ± SD. A repeated measures two‐way ANOVA was used to compare groups across time. Significance was set a p< 0.05. There were no significant differences between RTE times at week 0 (p= 0.52). There was a main effect of training across all groups in RTE (p=0.04) with a 14±43% increase in RTE in the CON, 13±33% increase in IM, and 55±86% increase in DG. There was a significant increase in body fat in the DG compared to CON at week 2 (CON 7.1±4.5% DG 13.4±2.3%, p=0.002), week 3 (CON 7.2±4.8% DG 11.6±2.6, p=0.02), and week 4 (CON 7.0±4.5% DG 11.6±1.9%, p=0.006); however, there was no difference between groups at week 8. There was a significant effect of time on body weight and lean mass, demonstrating normal growth (p<0.0001). TRF did not have a significant effect (p=0.24) on body weight, however there was a significant decrease in lean mass in TRF groups at week 8 (CON 24.7±2.2g, IM 22.8±2.1g, DG 22.7±1.8g, p=0.03). Although there was a small decrease in lean mass, TRF did not lead to a change in performance as measured by RTE and timing of fasting did not impact either RTE or body composition. This suggests that performance may not be substantially impacted in individuals using TRF, regardless of the timing of the feeding window.

Support or Funding Information

Funded by the University of Memphis School of Health Studies
Metabolic rewiring of the hypertensive kidney
Authors: Rinschen Markus M. , Palygin Oleg , Siuzdak Gary , Staruschenko Alexander
Published: April 2020

Hypertension is a persistent epidemic across the developed world that is closely associated with kidney disease. Here, we applied a metabolomics, phosphoproteomics and proteomics strategy to analyze the effect of hypertensive insults on kidneys. Our data established the metabolic aspects of hypertension‐induced glomerular sclerosis, including lipid breakdown at early disease stages and activation of anaplerotic pathways to regenerate energy equivalents to counter stress. For example, branched‐chain amino acids and proline, required for collagen synthesis, were depleted in glomeruli at early time points. Further, indicators of metabolic stress were reflected by low levels of ATP and NADH and increased abundance of oxidized lipids derived from lipid breakdown. These processes were specific to kidney glomeruli where metabolic signaling occurred through mTOR and AMPK signaling. Quantitative phosphoproteomics combined with computational modelling suggested that these processes controlled key molecules in glomeruli and specifically podocytes, including cytoskeletal components and GTP‐binding proteins, which would be expected to compete for decreasing amounts of GTP at early time points. As a result, glomeruli showed increased expression of metabolic enzymes of central carbon metabolism, amino acid degradation, and lipid oxidation, findings observed in previously published data from other disease models and patients with glomerular damage. Overall, these results suggest that metabolic interventions could be potentially useful in treating hypertension‐induced kidney disease.
Investigating the Role of NHE1 in Idiopathic Pulmonary Fibrosis
Authors: Hanowski Stephanie , Wallert Mark A.
Published: April 2020

Idiopathic pulmonary fibrosis is a chronic lung disorder characterized by thickening, stiffening and scaring of tissue within the lungs. Affected individuals develop shortness of breath and progressive reduced respiratory function. In order to be able to analyze this process two cell lines will be compared throughout the project. The first being LL29 cells which are human fibroblasts that were derived from a patient with idiopathic pulmonary fibrosis. In comparison to those cells will be further investigation of WI‐38 cells which are derived from normal lung tissue. In fibroblast cells, TGF‐b1, LPA, and 5HT will be investigated to differentiate between the two cell lines through analysis of their proliferation, stress fiber formation, collagen contraction and myofibroblast differentiation. Transforming growth factor beta 1 (TGF‐b1) is a cytokine that is a growth factor implicated in the pathogenesis of pulmonary fibrosis and is involved in differentiation, proliferation and matrix production of fibroblasts. Serotonin (5‐HT) is a signaling molecule that that functions through a G‐protein coupled receptors that support the increase of TGF‐b1 and the development of the fibrotic phenotype. This hormone is involved in wound healing and stimulating inflammation. LPA is a bioactive lipid signaling molecule that plays a role in mediating inflammation and activating TGF‐b1 signaling. Fibrosis ultimately results in low blood flow and hypoxia in the tissue, a microenvironment in which is closely associated with the upregulation of the sodium‐hydrogen exchanger isoform 1 (NHE1). NHE1 is a ubiquitously expressed protein that exchanges one extracellular Na+ for one intracellular H+. This regulates intracellular pH and cell progression through the cell cycle. When NHE1 is upregulated it supports increased cell proliferation and migration, indicating that it may play a vital role in the behavior of fibroblasts in idiopathic pulmonary fibrosis. Here we evaluate NHE1‐dependent changes in cell proliferation, stress fiber formation, α‐smooth muscle actin expression and collagen contraction.
MATLAB Tool for Color Comparative Analysis in Fixed Specimens. A Five Solution Single Blind Controlled Trial
Authors: Mejia Gabriel Mateo , Pedraza Juan Daniel , Rueda-Esteban Roberto Javier
Published: April 2020

Formaldehyde fixation avoids decomposition process of cadaveric specimens
1, making them useful for anatomy teaching and research
2. However, formaldehyde leads to fresh appearance loss in the tissue, which reduces its academical value. Although some color recovery solutions have been presented
3,
4, no standardized method for quantitative color assessment in fixed tissues has been proposed.

Our aim of is to present a MATLAB tool for color recovery analysis in formaldehyde fixed tissues.

Four different animal tissues (cardiac and skeletal muscle, kidney and liver), previously fixed with 10% formaldehyde (v/v) were treated in five different solutions (mineral staining, sodium bisulfite, sodium bicarbonate, GERDEX and modified Chilean solution
3). Tissues were photographed at different stages of preservation. Analysis was carried out in two different spaces of chromatic representation (RGB and HSV).

A computerized color comparison tool was developed allowing visualization of the chromatic presence in RGB color space through a three‐dimensional distribution (color cloud). Besides color cloud intersection percentage, frequency histograms of RGB distributions and the color saturation (S) distribution were used to generate performance metrics based on the Bhattacharyya distance. Each metric addressed one specific desired characteristic of a color recuperated specimen.

Mineral staining proved to be the solution with the best overall performance across most of the proposed metrics, significantly recovering the color compared to fresh tissue. Although significant results were obtained, future works implementing more robust methods of comparison, that involve metrics based on multiple desirable characteristics of a specimen are necessary.

The MATLAB tool developed showed to be useful for the quantitative color analysis and comparison in formaldehyde fixed tissues. Further studies should be done to standardize quality metrics of existing and upcoming preservation techniques.

Support or Funding Information

Anatomy Laboratory, School of Medicine, Universidad de los Andes.
Development of a gel filtration protocol that eliminates precipitation during refolding of chemically denatured proteins
Authors: Odunuga Odutayo , Tovar Carmel N.
Published: April 2020

Purification of recombinant proteins in denaturing conditions has many practical advantages. Chemical denaturants such as urea and guanidine hydrochloride are used to solubilize recombinant proteins from inclusion bodies. Proteins purified in denaturing conditions generally contain fewer contaminants compared to their counterparts purified in native buffers; thus reducing the number of steps in the purification scheme. Chemically denatured proteins can be stored for long time in buffer containing the denaturant and then refolded as required. Refolding is commonly performed by equilibrium dialysis and sometimes on metal affinity columns by diluting out the denaturant and allowing the protein to fold back into its native state. The refolding steps often result in significant loss of protein through aggregation. Using a modified gel filtration technique, we successfully refolded a spectrum of proteins that either are highly aggregation‐prone or contain several disulfide bonds or both, back to their native states. Some of the proteins are well known to precipitate significantly during refolding. However, using this technique, precipitation was either minimal or non‐existent. Secondary and tertiary structural analyses coupled with functional assays confirmed that these proteins were correctly refolded and biologically active. This strategy provides a robust approach to refolding denatured proteins, and simultaneously performing buffer exchange and additional purification steps.

Support or Funding Information

Robert A. Welch Foundation Grant #AN‐0008
Effects of ambient temperature on place conditioning elicited by abused psychostimulants in mice: role of methylexenedioxy moiety
Authors: Simmons Simeon , Russell Lauren , Fantegrossi William
Published: April 2020

Preclinical studies of the pharmacological and toxicological effects of drugs of abuse only rarely mimic the settings in which these substances are used by humans. In the case of psychostimulant drugs, human users often administer these compounds in party or musical festival settings characterized by loud noise, crowding, and warm ambient temperature. Each of these environmental factors may impact numerous drug effects, including thermoregulation, locomotor stimulation and lethality. Our previous work with 3,4‐methylenedioxymethamphetamine (MDMA) and 3,4‐methylenedioxypyrovalerone (MDPV) suggests that the presence of a methylenedioxy ring moiety may be required for a given drug to display these environment‐dependent effects. In these studies, we were specifically interested in testing this hypothesis with regards to abuse‐related effects in mice. We used conditioned place preference to establish dose‐effect curves for apparent rewarding effects for two pairs of psychostimulant drugs which differ structurally only in the presence or absence of a methylenedioxy ring. We studied two amphetamine analogues (MDMA and methamphetamine) and two cathinone analogues (MDPV and α‐pyrrolidinopentiophenone [α‐PVP]) at both a cool (20°C) and a warm (28°C) ambient temperature. As expected, all four drugs elicited significant dose‐dependent place preference at the cool ambient temperature. Doses of MDMA and MDPV – which both contain methylenedioxy rings – which were devoid of place preference effects in the cool ambient temperature elicited significant preference at the warm ambient temperature. This was not the case for methamphetamine or α‐PVP – which both lack the methylenedioxy ring – as doses of both compounds which were ineffective at the cool temperature remained ineffective at the warm temperature. These studies suggest that abuse of psychostimulants containing a methylenedioxy ring may be potentiated by warm ambient temperatures, which are commonly found in the environments where they are typically used by humans. Furthermore, this suggests that preclinical abuse liability studies conducted at standard laboratory temperatures may underestimate the potency of psychostimulant drugs with a methylenedioxy moiety.

Support or Funding Information

These studies supported by an institutional ASPET SURF award (SS), T32 DA022981 (LNR) and R01 DA039195 (WEF).
Determining the Structure and Kinetics of Desferroxiamine D Variants: E445A and H443A
Authors: Rosales Vincent , Gahir Paven , Hoffmann Katherine
Published: April 2020

Virulent bacteria such as MRSA and anthrax produce siderophores which are successful in competing for and chelating iron from their host environment. These are synthesized by a family of enzymes called NIS synthetases, of which DesD is a model enzyme out of Streptomyces coelicolor. DesD contributes to the catalytic formation of siderophore Desferrioxamine E, a siderophore formed by iterative combination of three molecules of hydroxysuccinylcadaverine along with stoichiometric amounts of cofactor ATP. We have previously characterized the kinetic constants for ATP and the largest substrate, called dfoG, as well as binding studies for the cofactors and analogs and structural models of the apo and analog‐bound enzyme. The purpose of the current study is to determine the sidechains involved in catalysis by using site directed mutagenesis, kinetic studies, binding studies and crystallography to analyse the impact of the mutation. This work will focus on two variants: E445A and H445A which we hypothesize will be critical for cofactor binding (E445A) and catalysis (H445A) based on alignments and structural analysis. The current work will present overexpression and purification of these two variants, along with the biochemical characterization of their functions.

Support or Funding Information

This research was supported in part by the National Science Foundation (NSF‐RUI grant 1716986 to K.M.H.).
PhUn Day: Third Times a Charm
Authors: Rascon Jozelyn A. , Trujillo Elizabeth , Aguilar Brianna C. , Guerrero Mariana , Keller Aaron A. , Rico Andrea A. , Nunez Victoria A. , Gurovich Alvaro
Published: April 2020

Physiology Understanding (PhUn) week consists of hands‐on activities and presentations, which incorporate the understanding of physiology through interactive fun. The University of Texas at El Paso’s Rehabilitation Sciences Program has hosted PhUn week in different schools throughout the El Paso community for a total of three years. Our first year in 2017, PhUn week was hosted at Hornedo Middle School and the activity reached seventh‐grade students (24). The following year in 2018, PhUn week was hosted at Tippin Elementary School and its whole second grade (96 students) and teachers (5) participated in the event. Although the American Physiological Society is no longer sponsoring PhUn week, we did not want to let this great community outreach project come to an end. Therefore, this year (2019) PhUn “day” was hosted at Kohlberg Elementary School in El Paso, Texas with the participation of its entire third‐grade class (80 students) and teachers (5). Since many of the students in the Rehabilitation Sciences program have participated in PhUn week in the past, we received great support in planning the event. We split up into teams and designed 5 new and exciting stations using electronic physiology data acquisition systems. These stations included reaction time, electromyography, and a stroke simulation which was designed to immobilize one side of the body and challenge cognition. We also had a working heart model showing the circulation of blood, and a sensory integration station in which students learned how the brain receives information from the 5 senses, organizes this information and responds appropriately. We used the Biopac MP40 system to conduct the reaction time and EMG stations. Each group of volunteers had one leader who participated in the previous years who was able to train the other students in the use of the Biopac MP40 system. We split the 80 students into groups of 16 and had them rotate every 20 minutes. The students, teachers, and other Kohlberg faculty, as well as UTEP students, had a lot of fun and learned about physiology at the same time. We could see the excitement and effect the event left on the young students as many left excited about science, which is the main goal of PhUn week. Overall, it was a great experience that required a lot of preparation and training but was worth the impact it had on the students involved.

Support or Funding Information

Research reported in this poster was supported by the National Institute of General Medical Sciences of the National Institutes of Health under linked Award Numbers RL5GM118969, TL4GM118971, and UL1GM118970. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
PBK is a Novel Regulator of Vascular Remodeling in Pulmonary Arterial Hypertension
Authors: Bordan Zsuzsanna , Chen Feng , Li Xueyi , Batori Robert , Haigh Stephen , Meadows Mary-Louise , Singla Bupesh , Csanyi Gabor , Su Yunchao Karoly , Barman Scott Karoly , Fulton David
Published: April 2020

Pulmonary Arterial Hypertension (PAH) is an insidious disease that develops gradually and becomes symptomatic only in the latter stages. In PAH, along with increased pulmonary artery (PA) pressure, the PAs in the lungs continue to become more muscular, narrower restricting blood flow through the lungs. Increased proliferation of pulmonary arterial smooth muscle cells (PASMC) are largely responsible for the development PA hypertrophy. Because excessive proliferation of PASMC in PAH shares many characteristics with other hyperproliferative diseases such as cancer, there is a growing interest in repurposing therapeutic targets in cancer, for the treatment of PAH. In preliminary studies, we screened a microarray of isolated PAs from control and monocrotaline (MCT)‐induced PAH rats for novel genes that may be responsible for the proliferation of PASMCs in PAH. We found that the gene PDZ‐Binding Kinase (PBK) was significantly higher in PAs from MCT rats versus controls. PBK (also known as TOPK or T‐cell‐originated Lymphokine‐activated killer protein kinase) is a serine/threonine kinase that plays a key role in several types of cancer. Although PBK levels are typically very low in healthy tissues, expression levels are significantly increased in cancer cells, which correlates with a poor prognosis of breast, gastric and lung cancers. We performed immunostaining, and found that PBK was highly upregulated and concentrated in the smooth muscle layer of both PAH rats (MCT and Sugen/Hypoxia induced) as well as in human PAs with PAH. To determine a functional role for PBK in PASMCs, we generated an adenovirus encoding PBK and found that increased expression stimulated PASMC proliferation and resistance to apoptosis. In contrast, silencing PBK or in vitro pharmacological inhibition (HI‐TOPK‐032, 2μM) significantly (p<0.05; n=5) reduced PASMC proliferation and increased cell death. Furthermore, the specific PBK inhibitor OTS514 (5mg/kg/day for 14 days) reduced right ventricle hypertrophy (Fulton Index) and improved PA remodeling in the MCT‐induced model of PAH. Collectively, these findings suggest that PBK drives pulmonary artery smooth muscle proliferation leading to abnormal vascular remodeling and the development of PAH.

Support or Funding Information

AHA 19PRE34450087

R01HL125926‐03
Importance of Selected Acinetobacter AAC(6′)‐Ig Active Site Residues on Escherichia coli Susceptibility to Aminoglycosides
Authors: Barol Irina , Pradhananga Anjani , Pennings Pleuni , Kuhn Misty L.
Published: April 2020

Aminoglycosides are broad‐spectrum antibiotics commonly used to treat infections caused by Gram‐negative pathogens. However, bacteria become resistant to these antibiotics by acquiring or utilizing innate aminoglycoside acetyltransferases (AACs) that modify the drug. For instance, Acinetobacter haemolyticus has acquired the AAC(6′)‐Ig enzyme and is resistant to multiple aminoglycosides. However, our current understanding of the key residues of the active site that are critical for enzymatic activity of this enzyme is limited. Therefore, we selected two residues in the active site of the protein that formed either H‐bonds or exhibited pi‐pi stacking with tobramycin in the 3D structure of the enzyme and mutated them to bulky or charged amino acids. Next, we examined the susceptibility of Escherichia coli in the presence and absence of these over‐expressed Acinetobacter proteins toward four aminoglycosides. We found the identity of the residue substituted at these positions altered their susceptibility to these antibiotics, which provides insight into how this enzyme recognizes and modifies its diverse substrates.

Support or Funding Information

Research reported in this work was supported by the National Institute of General Medical Sciences of the National Institutes of Health under Award Number R35GM133506 (to MLK).
Foot compartments. How many and it’s clinical relevance
Authors: Quiroga-Garza Alejandro , Vázquez-Zorrilla Daniel , Millan-Alanis Juan Manuel , Alvarez-Villalobos Neri Alejandro , Salinas-Alvarez Yolanda , Guzman-Lopez Santos , Elizondo-Omaña Rodrigo Enrique , Fernandez-Rodarte Bernardo Alfonso
Published: April 2020

Introduction

Several authors have assessed the foot with diverse methods, with discrepancies towards the number of compartments. Treatment for foot compartment syndrome is not standardized, but primarily consists of liberating pressure from these, to avoid ischemia, nerve damage, and malformation. Our objective is to synthesize the existing evidence regarding the compartmental anatomy of the foot

Materials and methods

A systematic review of all publications evaluating normal foot compartment anatomy was performed using the MEDLINE, Scopus, Web of Science, and EMBASE databases. Data were recorded and analyzed by the reviewers.

Results

After filtering results, 10 studies were included in the final analysis. All were performed in cadavers except one. The primary difference was the region studied, half focusing on the plantar region, and the other half evaluating the whole foot. There seems to be an agreement regarding the number of compartments in the plantar region (three major compartments divided by the medial and lateral intermuscular septum), nevertheless, disagreements across authors tend to arise when describing its dorsal section. Only two studies were ranked with an overall low risk of bias using the AQUA checklist. These two agreed on 9 total compartments, however, one included the skin as a 10th compartment, although by definition (space occupied by tissue and bound by fascia or bone) it is not a compartment.

Conclusion

Discrepancies in the number of compartments exist between authors. This review provides the best available evidence with an anatomical analysis of data and concludes 9 compartments of the foot. This anatomical description should be taken into account and referenced in clinical reports of foot compartment syndrome treatment to determine the best treatment in a future meta‐analysis based on the same classification.
GlyGen ‐ Computational Resources for Glycoscience
Authors: Tiemeyer Michael , Ranzinger Rene , Kashay Robel , Edwards Nathan , Mazumder Raja , York William
Published: April 2020

Advancing our understanding of the roles that glycosylation plays in development and disease is frequently hindered by the diversity of the data that must be integrated to gain insight into these complex phenomena. GlyGen is a maturing initiative, supported by the NIH Common Fund, with the goal of democratizing glycoscience research by developing and implementing a comprehensive data repository that integrates diverse types of data, including glycan structures, glycan biosynthesis enzymes, glycoproteins, three‐dimensional glycoprotein structures, along with genomic and proteomic knowledge. To achieve the highest possible integration and impact, GlyGen has established international collaborations with database providers from different domains (including but not limited to EBI, NCBI, PDB, GlyTouCan and UniCarbKB) and glycoscience researchers. Information from these resources and groups are standardized and cross‐linked to allow queries across multiple domains. To facilitate easy access to this information, an intuitive, web based interface (
http://glygen.org/) has been developed to visually represent the data and the connections between datasets. In addition to the browser‐based interface we are also developing RESTful webservice‐based APIs and SPARQL endpoints, allowing programmatic access to integrated datasets. For each glycan and glycoprotein in the dataset, GlyGen provides a details page that integrates available information. Individual details pages are interlinked with each other allowing easy data exploration across multiple domains. For example, users can browse from the webpage of a glycosylated protein to the glycan structures that have been described to be attached to this protein, and, from there, to other proteins that carry the same glycan. All information accessed through GlyGen is linked back to original sources, allowing users to browse through information pages in other resources. Our goal is to provide scientists with an easy way to access the complex information underlying state‐of‐the‐art knowledge that describes the biology of glycans and glycoproteins. To maximize usefulness of the GlyGen resource by the broadest possible user population, we have implemented a query interface that suggests likely “use‐case” questions. For instance, a question such as “What are the enzymes involved in the biosynthesis of glycan X in humans?” can be posed simply by providing minimal information (e.g. glycan X in the example). Answers are then returned following the completion of a query across multiple datasets and domains; the complexity of the query remains invisible to the user. Importantly, use‐case questions were developed as a result of outreach to potential users through community meetings and directed contacts. To schedule a demo of GlyGen or add your data to GlyGen contact Michael Tiemeyer (
mtiemeyer@ccrc.uga.edu) or Raja Mazumder (
mazumder@gwu.edu).

Support or Funding Information

Supported by NIH Common Fund U01 GM124267‐01
Calcium‐Dependent Dual Oxidase 2 is a Novel Source of Reactive Oxygen Species Implicated in Glomerular Mesangial Cell Fibrotic Response to Angiotensin II
Authors: Baistra Teresa , Tristan Anais , Ford Bridget Marie
Published: April 2020

The vasoactive peptide angiotensin II (Ang II) contributes to the initiation and the progression of glomerular fibrosis via activation of glomerular mesangial cells (MCs) and subsequent extracellular matrix expansion. We have previously shown that oxidative stress is critical for MC fibrotic response to Ang II. Here, we demonstrate that Dual oxidase 2 (Duox2), a member of the Nox/Duox family of NADPH oxidases, is present in MCs and that its protein expression is upregulated by Ang II.

Small interfering RNA (siRNA)‐mediated downregulation of Duox2 significantly reduces Ang II‐induced increase in reactive oxygen (ROS) generation and prevents the stimulatory effect of Ang II on MC fibrotic injury (as assessed by measuring α‐smooth muscle actin and fibronectin expression).

To demonstrate that Duox2 activation is Ca2+‐dependent, we show that the extracellular Ca2+ chelator BAPTA prevented Ang II‐induced ROS generation and the stimulation of MC fibrotic injury by Ang II. Moreover, treatment of MCs with ionomycin resulted in increased ROS production and enhanced MC fibrotic injury. These effects were abrogated by siRNA targeting Duox2. Fura‐2 fluorescence was utilized as well to show calcium mobilization in response to Ang II and this effect was abrogated with siDuox2 transfection. These data indicate that Ang II‐stimulated Duox2 activation and ROS generation subsequently lead to MC fibrotic injury.

In summary, we have identified a novel role for Duox2 as a major source of ROS in response to Ang II and established the significance of Duox2 in Ang II‐mediated MC activation and fibrotic injury. Therapeutic targeting of this pathway may prevent or reverse pathophysiologic manifestations of renal fibrotic diseases.

Support or Funding Information

This project was funded by the University of the Incarnate Word, Office of Research and Graduate Studies and the following grants: NRSA 5T32HL007446‐32
Unbiased Proteomics Supports a Key Role for Mitochondria in Skeletal Muscle of Highly Functioning Octogenarians
Authors: Ubaida-Mohien Ceereena , Lyashkov Alexey , Spendiff Sally , Taivassalo Tanja , Hepple Russell T.
Published: April 2020

Introduction

Skeletal muscle mass and function decline with aging, and more precipitously after the age 75 y. To help provide insights into biologically relevant mechanisms for preserving muscle mass and function in advanced age, in this study we performed proteomics on skeletal muscle of world class octogenarian track and field athletes in comparison to healthy octogenarian non‐athletes.

Methods

Muscle cross‐sectional area by MRI and a vastus lateralis muscle biopsy were performed in 15 octogenarian world class track and field athletes (8 of whom were world record holders in their discipline at the time of testing) and 14 non‐athlete age‐ and sex‐matched non‐athlete controls. From these subjects, a portion of muscle from a subset of 12 master athletes (MA mean age 81.19 ± 5.1 y) and 12 non‐athlete controls (NA mean age 80.94 ± 4.5 y) was used for liquid‐chromatography mass spectrometry to generate quantitative tandem mass tag proteomics data. In addition, we measured mtDNA copy number, COX/SDH histochemistry to identify respiratory compromised fibers, and Western blot of mitochondrial inner and outer membrane proteins.

Results

Muscle cross‐sectional area was higher in MA. Tandem mass spectrometry identified over 6000 proteins, and significant differences in abundance were found between NA controls and MA for more than 800 proteins. A pathway analysis revealed that pathways involved in mitochondria (e.g., TCA cycle, respiratory electron transport, cristae formation, sirtuins) were higher in MA, while proteins in pathways involved in the spliceosome and nuclear pore were downregulated in MA. Finally, 8 mtDNA‐encoded proteins that were included in the analysis were elevated in MA versus NA. These proteomics data are consistent with phenotypic data showing MA have higher mtDNA copy number, fewer respiratory chain compromised muscle fibers, and an increased ratio of ETC subunits (inner mitochondrial membrane proteins) relative to VDAC (outer mitochondrial membrane protein), suggesting an increase in cristae formation.

Conclusion

Our data underscore that mitochondrial pathways are key to maintaining a high level of physical function in advanced age. With the current study design we cannot determine the degree to which these differences are attributable to the physical activity habits of MA, but it is likely to play a role.

Support or Funding Information

CIHR (MOP 125986 to RTH)

NIA Intramural Research program
Optimizing Kinetic Assay Conditions to Study Bacterial Protein Lysine Acetyltransferases in Escherichia coli
Authors: Jew Kristen , Kho Ellen , Kuhn Misty L.
Published: April 2020

Protein acetylation is a widespread post translational modification that can be observed in prokaryotes. Recent studies have shown that a multitude of bacterial proteins undergo two types of lysine acetylation: non‐enzymatic and enzymatic. Non‐enzymatic acetylation via the small molecule acetyl‐phosphate (AcP) has been the predominant focus of prior studies. However, recent work indicates that enzymatic protein acetylation by a set of Ne‐lysine acetyltransferases (KATs) in Escherichia coli is extensive and offers new opportunities to more deeply study the role of enzymatic protein acetylation in bacteria. One of the barriers to studying KAT acetylation is that current enzymatic acetylation methods do not appear to consider self‐acetylation properties of some KATs, which can lead to inconclusive results. Thus, finding optimal conditions for controlling or accounting for KAT self‐acetylation is vital to understand its role in enzymatic acetylation of substrate proteins. Therefore, we have examined the self‐acetylation properties of YfiQ and its effect on acetylating a previously uncharacterized protein substrate. We found YfiQ is already acetylated after heterologous expression and purification, which complicates interpretation of enzymatic assay results. Therefore, we are currently optimizing our system to account for this characteristic and are exploring different reaction conditions to study the enzymatic acetylation of the previously uncharacterized protein more deeply.

Support or Funding Information

Research reported in this work was supported by the National Institute of General Medical Sciences of the National Institutes of Health under Award Number R35GM133506 (to MLK).
To what extent have Disability Resource Centers evolved to accommodate the challenges of active learning in large enrollment STEM courses?
Authors: Guerrero Frank Anthony , Gin Logan E. , Brownell Sara
Published: April 2020

While active learning teaching methods have been shown to improve student achievement in science, technology, engineering, and math (STEM), the increased interactions among students can also present unique challenges for students from underrepresented social identities. One proposed underrepresented group of individuals who may face challenges with active learning are students with disabilities who request academic accommodations from Disability Resource Centers (DRCs). DRCs are offices on university campuses that provide academic and social services for students with disabilities and other diagnosed medical conditions. Academic accommodations often include note‐taking services, preferential seating, extended time for exams, closed captioning of videos, and interpreters. However, as more and more classes are moving away from traditional lectures to adopting active learning methods, are we providing the right accommodations for students? Could we be disadvantaging students who normally would be receiving accommodations in traditional lectures? In this exploratory study, we identified commonly implemented active learning strategies and reviewed the literature on what reported disadvantages these activities may present for students. We then contacted directors of DRCs from 305 universities with large undergraduate student populations and large enrollment science courses based on the Carnegie Classification of Institutions of Higher Education. We interviewed directors to identify how familiar they are with the term of active learning and what accommodations, if any, they currently have for students in active learning science classrooms along with any challenges they have experienced when accommodating students with disabilities in active learning science courses. Our data suggest that directors are generally aware of “active learning” and have encountered it in their position when talking with students and faculty. However, few DRCs have policies or protocols in place to specifically address accommodations needed for active learning courses. Thus, accommodations for active learning are generally determined retroactively or on a “case‐by‐case basis”, which requires students to be the ones responsible for identifying aspects of active learning courses that they struggle with and report these challenges to the DRC in order to receive appropriate accommodations. With this study, we hope to provide a foundation for creating more inclusive active learning classrooms for students with disabilities.

Support or Funding Information

National Science Foundation
Static Muscle Stretching Enhances Vascular Responsiveness of the Tibial Nutrient Artery
Authors: Reid-Foley Emily Carole , Caldwell Jacob , Dewell Isabella , Monroe Richard , Naganoma Naomi , Makadia Ruchickumar Anilkumar , Eazer Julia , Perez Adrioano , Griesheimer Jessica , Sadowsky Dylan , Bedwell Kristin , Park Hyerim , Hotta Kazuki , Delp Michael , Muller-Delp Judy
Published: April 2020

The magnitude of bone formation and remodeling is linked to both the magnitude of strain placed on the bone and the perfusion of bone. We have previously shown that daily static stretching of the ankle flexor muscles in aged rats results in increased blood flow to the stretched muscles and to the proximal tibial metaphasis during walking exercise. The purpose of this study was to determine the effects of daily static muscle stretching on vasoreactivity of the nutrient artery that perfuses the proximal tibial metaphasis. Static stretching of ankle flexor muscles was performed in aged male Fischer 344 rats (20 months) by placement of a dorsiflexion splint on the left ankle for 30 min/day, 5d/wk for 4wks. The right hindlimb served as a contralateral control (unstretched) limb. After the 4 wk stretching intervention, the tibial nutrient artery was isolated from both the stretched and unstretched limb. Vasoconstrictor responses to the adrenergic agonist, phenylephrine (10‐9‐10‐4M) and vasodilatory responses to acetylcholine (10‐9‐10‐4M) and Dea‐NONO‐ate (10‐9‐10‐4M) were evaluated. Vasoconstrictor responses to phenylephrine were significantly increased in the tibial nutrient artery from the stretched limb as compared to those from the unstretched limb (maximal constriction, stretched limb = 54±4%, maximal constriction, unstretched limb = 42±6%; P<0.05 stretched vs. unstretched). Endothelium‐dependent vasodilation to acetylcholine was also significantly increased in the tibial nutrient artery from the stretched limb (maximal dilation = 62±5%) as compared to the unstretched limb (maximal dilation = 41±5%); P<0.01, stretched vs. unstretched). Endothelium‐independent dilation to the NO donor, Dea‐NONO‐ate was not different in the tibial nutrient arteries from the stretched and unstretched limbs. These data indicate that static muscle stretching alters the reactivity of both the smooth muscle and the endothelium of the tibial nutrient artery, leading to enhanced vasoconstrictor and vasodilatory responsiveness of the artery. This enhancement of vascular function in the nutrient artery may contribute to increased perfusion of the tibia during walking exercise following 4 weeks of daily static stretching.

Support or Funding Information

Supported By: NIH R15AG055029
An Osteo‐Developmental Baseline for Cranial Casque Anatomy of Southern Cassowaries Better Informs Functional Interpretations
Authors: Green Todd L. , Watanabe Akinobu , Gignac Paul M.
Published: April 2020

Seemingly bizarre cranial ornaments can be found among most major tetrapod groups. The casques (i.e., dorsal skull projections of bone surrounded by keratin sheathing) of modern cassowaries (Casuarius) are perhaps the most enigmatic of modern Aves. Both the biological role(s) and anatomical configuration of this headgear has been debated for the past 150 years, limiting our understanding of the life history of these unique birds as well as the selective conditions under which cranial elaborations appear in archosaurs. Because these structures are poorly understood, it is essential to set an osteo‐developmental foundation from which biomechanical, behavioral, physiological, and functional studies can radiate from. To address the commonly proposed roles of cassowary casques (e.g., ramming, vocalization, thermoregulation, display), we conducted μCT analyses of cranial anatomy in a developmental series of southern cassowaries (C. casuarius). This allowed us to describe details of both external and internal anatomy as well as timings of sutural fusions and inflations of casque elements. We compared the developmental timing of casques to physical, behavioral, and reproductive maturity to determine the plausibility of each function. Our sample (n = 130) indicates the majority of casque growth occurs prior to sexual maturity; although, casque morphology changes substantially throughout adulthood. Deviation from midline is particularly common in the casques of C. casuarius and such asymmetries appear to be primarily dextral. Form does not support functions for either physical ramming or vocalization; however, thermoregulation and display are not refuted by ontogeny nor adult phenotype, necessitating more focused future study.

Support or Funding Information

2019 New York Institute of Technology College of Osteopathic Medicine (Akinobu Watanabe)

2019 Western Interior Paleontological Society ‐ Karl Hirsch Memorial Grant (Todd L. Green)

2018 American Association of Anatomists ‐ Visiting Scholarship (Todd L. Green)

2017 National Science Foundation ‐ Major Research Instrumentation Grant (Paul M. Gignac)

2016 Western Interior Paleontological Society ‐ Karl Hirsch Memorial Grant (Todd L. Green)

2015 National Science Foundation ‐ Early‐concept Grant for Exploratory Research (Paul M. Gignac)

2015 National Science Foundation ‐ Division of Environmental Biology (Paul M. Gignac)
Obesity‐Induced Sympathoexcitation is Associated with Glial Senescence in the Brainstem
Authors: Monteiro Raisa , Sivasubramanian Mahesh Kumar , Balasubramanian Priya , Subramanian Madhan
Published: April 2020

Previous studies from our laboratory showed that high fat diet‐induced obesity causes cellular senescence in the key brainstem region, the rostral ventrolateral medulla which is critical for the tonic and reflex control of sympathetic nervous system. Cellular senescence is characterized by a state of irreversible growth arrest and senescence‐associated secretory phenotype (SASP) in proliferating cells. In the current study, we wanted to investigate which cell type undergoes senescence in the brainstem in obesity. Neurons are post‐mitotic and do not undergo senescence, whereas glial cells can undergo senescence. Hence we hypothesized that obesity induces glial senescence in the brainstem. To address this hypothesis, 2‐month old C57BL/6J mice were fed with high fat diet (60% fat; n=5) and chow diet (10% fat; n=5) for 16 weeks. The animals were sacrificed at the end of the experiment, and their brains were collected for further processing. The freshly isolated brainstem was enzymatically digested (45 minutes, 37°C) and filtered through a 30μm mesh to form a cell suspension. Neuron isolation kit from Miltenyi Biotec was used to isolate glial and neuronal enriched cell population from the brainstem. RNA was extracted from these sorted cells and used for RT‐PCR analysis. Senescence was assessed using gene expression of cell cycle inhibitors and SASP factors. Data was analyzed by unpaired student’s t‐test and a p‐value less than 0.05 was considered statistically significant. We observed an increase in the gene expression of cell cycle inhibitors, p21 and p53 in the glial cell fraction isolated from the brainstem of obese mice compared to its lean counterparts. In addition, there was an increase in the mRNA levels of SASP factors such as the IL‐6 and MCP1 suggesting that obesity induces glial senescence in the brainstem. We were not able to obtain viable neurons for senescence analysis. Glial cells are known to play a supporting role in neuronal function through regulation of neurotransmission. Future studies will address glial cell specific mechanisms and understand how glia‐neuron crosstalk contributes to sympathetic nerve overactivity in obesity.

Support or Funding Information

NIH‐HL148844 and RED account funds