bluuebunny/crossref_metadata_2025_split huggingface dataset:
Critical role of arginase 2 in obesity‐induced metabolic dysregulation in female mice: Implication of macrophage inflammatory response
Authors: Eldahshan Wael , Atawia Reem T. , Meghil Mohamed M. , Fouda Abdelrahman Y. , Cutler Christopher W. , Caldwell Ruth B. , Caldwell Robert W. 
Published: April 2020

We have previously shown that deletion of the mitochondrial isoform of the ureahydrolase enzyme (A2) protected against obesity‐induced metabolic dysregulation in “male” mice fed high fat high sucrose diet (HFHS) for 16 weeks. Additionally, A2 expression was upregulated 1.5‐fold in visceral adipose tissue (VAT) of WT "male" mice fed HFHS vs WT fed normal chow diet (ND). Interestingly, A2 expression was elevated 3‐fold in VAT of WT HFHS "female" mice vs WT ND. In the current study, we determined the consequences of global A2 deletion in “female” mice on the same diet protocol. Body weight was measured weekly, adiposity was measured using nuclear magnetic resonance and metabolic activity was assessed using indirect calorimetry. Increases in body weight in WT HFHS female mice, VAT weight and total adiposity were abrogated in A2−/− HFHS mice by 24, 84 and 54%, respectively (p<0.05). Glucose tolerance tests showed a significantly reduced area under the curve in A2−/− HFHS mice vs WT (p<0.05). The leaner phenotype observed in A2−/− mice was in line with the improved metabolic activity as evidenced by increased energy expenditure, volume of O2 consumed and CO2 produced in A2−/− mice fed HFHS vs WT HFHS. Obesity‐induced VAT inflammation and vascular rarefaction contribute to unhealthy expansion of adipose tissue resulting in disrupted metabolic and endocrine functions. VAT sections from WT HFHS stained with isolectin B4 revealed reduced vascular density which was preserved in A2−/− HFHS. Flowcytometry analysis of stromal vascular fraction isolated from VAT of WT HFHS mice showed an increase in proinflammatory M1 macrophages (F4/80+CD11c+) (p=0.06) and a significant decrease in antiinflammatory M2 macrophages (F4/80+CD206+) (p<0.05), the latter was not affected in male mice. These effects were blunted in A2−/− HFHS female mice, reducing the M1/M2 ratio towards a favorable, less inflammatory state. Given the role of A2 in polarizing macrophages to an inflammatory state in vivo, we wished to determine the specific effect of macrophage A2 on inflammatory responses. Peritoneal macrophages from WT and A2−/− female mice were isolated, cultured in vitro and treated with 100 ng/ml lipopolysaccharide (LPS) or vehicle for 24 hr. WT macrophages exposed to LPS showed an activated inflammasome pathway (increased expressions of NLRP3 and pro‐IL‐1β) compared to control group (p<0.05). These effects of LPS were blunted in isolated A2−/− macrophages, indicating that A2 promotes inflammatory macrophage responses in female mice. Collectively, our data show that A2 is a critical mediator of obesity‐induced metabolic dysregulation, VAT vascular rarefaction and increased macrophage inflammatory responses in female mice.Support or Funding InformationR01 HL070215, R01 EY01176 & AHA17PRE33660321
Effects of Vacuolar H+‐ATPase Inhibition and the a2 Isoform on Secretion and Activation of Cathepsin B in MDA‐MB231 Breast Cancer Cells
Authors: Henry Abhijeet Anil 
Published: April 2020

V‐ATPases are multi‐subunit H+ pumps that acidify intracellular compartments and are important for immune functionality, synaptic signaling, and other processes. They are at the cell surface of the highly metastatic breast cancer cell line MDA‐MB231 and may contribute to its metastatic phenotype. We hypothesize that V‐ATPases create a low pH environment that promotes tumor cell invasion by activating secreted cathepsins. Studies indicate that cathepsins secreted by cancer cells are involved in metastasis. Cathepsins cleave extracellular matrix proteins and activate other proteases, facilitating tumor invasion. We are interested in a connection between cell surface V‐ATPases, activation of secreted cathepsins and the metastatic phenotype of MDA‐MB231 cells. Previous data from our lab indicates that inhibition of V‐ATPases by a general inhibitor reduced the activity of secreted cathepsin B, but did not cathepsin L. However, although there was a trend, difference in activity for secreted cathepsin B after V‐ATPase inhibition was not statistically significant. Our current data builds on that trend to show a significant difference in the activity of secreted cathepsin B. To investigate the role of V‐ATPases in the activation of cathepsins further we are using CRISPR/Cas9 to knockout the gene for the V‐ATPase a2 isoform of subunit “a”. Published data indicates that the a3 and a4 isoforms are found in V‐ATPases at the cell surface of MDA‐MB231 cells. Additionally, it was found that the a1 and a2 isoforms are not present on the cell surface, thus we hypothesize that the a2 isoform knockout will not affect the activity of secreted cathepsin B, but will affect the activity of cathepsin B in the cell interior. Separate abstracts submitted by our lab are focused on the a1, a3, and a4 isoform knockouts.Support or Funding InformationDenison University Anderson Summer Research Assistantship
Interaction between hyperbaric oxygen therapy and prostaglandin synthesis inhibition in the formalin pain test
Authors: Cruz-Martinez Sheila Belen , del Carmen Castillo-Hernández María , Guevara-Balcázar Gustavo , Correa-Basurto José , Ríos-Ramírez Diego Alejandro , Valencia-Hernández Ignacio 
Published: April 2020

BackgroundPain is the main symptom of inflammatory diseases, such as diabetes mellitus, hypertension, osteoarthritis among others. Lipopolysacaccharide from E. coli (LPS) has been used to induce an inflammatory process. Prostaglandins has a role in inflammation so that NSAIDs are useful pharmacological tools to treat it. Hyperbaric oxygen therapy (HBOT) has also been used in some of these diseases. However, information about pharmacological interaction with HBOT and its mechanism is scarce. So, the purpose of this work was to study the interaction between LPS, HBOT and NSAIDs using a formalin pain test.Methods96 adults male Wistar rats (150 to 200 g) were used and 2 groups treated with LPS or its vehicle were formed and each of them was divided in the next subgroups (n=8 each): Control, indomethacin, rofecoxib, HBOT, HBOT/indomethacin and HBOT/rofecoxib. 20 μL of 2% formalin was injected into the plantar surface of the right hind paw. Then nociceptive behavior was evaluated as the number of flinches in 1 min every 5 for 60 min. LPS and HBOT were applied 4 and 2.5 h prior to formalin respectively. Additionally, PGE2 and PGI2 was quantified using RP‐HPLC‐UV.ResultsFormalin produces a nociceptive behavior that decreased in the first 10 min (phase I) and in the next 50 increased to a plateau and then become to reduce (phase II, inflammatory). LPS increased and HBOT and drugs treatment reduced the phase II, while PGI2 levels were increased with LPS and reduced with HBOT and drugs. The HBOT seems to increase the indomethacin antinociceptive effect but HBOT effect was lesser than control and levels of prostaglandins were similar than in absence of HBOT. LPS treatment reduced the rofecoxib and HBOT effect increasing PGE2 and PGI2 levels respectively. Finally, when HBOT is associated with LPS and indomethacin, an increase on AUC of formalin and PGI2 levels was observed.ConclusionsThe HBOT and prostaglandin synthesis inhibition were effective antinociceptive interventions. However, indomethacin but not rofecoxib increased the HBOT antinoceptive effect diminishing PGI2 levels. In presence of an inflammatory process, the effect of HBOT and rofecoxib but no indomethacin, the antinociception was lost due to an increase in prostaglandin synthesis. Therefore, there are an interaction between HBOT and PG synthesis inhibition and the presence of inflammation reduced the beneficial effects of physical or pharmacological interventions.Support or Funding InformationThe authors would like to acknowledge CONACYT (557096) for their financial support
Strategies for Autonomic Nervous System Mapping of Fiber Composition and Neural Circuitry Using Transmission Electron Microscopy in Support of SPARC Projects
Authors: Biscola Natalia P. , Bartmeyer Petra M. , Zhang Nianhui , Havton Leif A. 
Published: April 2020

The optimization of neuromodulation strategies is important for a development and refinement of therapies. The design of customized tools, such as electrical stimulating devices, depends on the detailed knowledge of nerve fiber composition and inter‐relationships between target organs, nerve populations, and synaptic circuitry. The autonomic nervous system gives support to organs and are composed by myelinated and unmyelinated fibers as well as pre‐ and post‐ganglionic neurons. Mapping an autonomic nerve such as the pelvic or vagus nerve that innervates peripheral tissues and understanding the synaptology of neurons in the cardiac and stellate ganglia may provide advanced knowledge for improved neuromodulation strategies. Transmission electron microscopy (TEM) is a high‐level technology that helps to identify and characterize axonal myelination and ultrastructure of unmyelinated fibers. TEM also allows for fine structural analysis of neural circuitry and innervation of autonomic targets. Immunogold detection techniques using TEM permits the identification and characterization of neuronal tracers in the nervous system. With the support from the Stimulating Peripheral Activity to Relieve Conditions (SPARC) program at NIH, we developed customized ultrastructural studies of the autonomic nervous system to facilitate refinement of neuromodulation strategies related to the autonomic control of cardiac, gastrointestinal, and lower urinary tract systems. Morphometric analysis is performed by automatic segmentation, and the development of a new strategy to calculate measurements of axon diameter, fiber diameter, myelin thickness, and G‐ratio provides a better understanding of fiber size for modelling studies. Both males and females from different species, including humans, are analyzed and compared. Implementation of common sampling techniques for nerves and ganglia across species provides increased rigor and reproducibility. TEM studies promote an improved understanding of functional studies and provide critical ultrastructural information for the development of new neuromodulation strategies.Support or Funding InformationSPARC/NIH 1OT2OD026585‐01 and Dr Miriam and Sheldon G. Adelson Medical Research Foundation (AMRF)
Is the scapula a good indicator of taxonomy?: A geometric morphometric analysis using macaque monkeys
Authors: Kenyon-Flatt Brittany , von Cramon-Taubadel Noreen 
Published: April 2020

In primates, scapular shape is often thought to correlate to locomotor patterns with distinct morphologies observed in arboreal versus terrestrial species. However, the extent to which intra‐generic morphological differences might be related to taxonomic differences as opposed to convergent locomotor behaviors remains to be tested. Thus, we tested the hypothesis that closely related, but behaviorally distinct, species may exhibit variation in their scapular morphology that match known phylogenetic relationships among the specious macaque monkey. Our sample (n=230) represented nine species; M. fascicularis, M. mulatta, M. fuscata, M. arctoides, M. radiata, M. nigra, M. nemestrina, and M. sylvanus and a Colobine outgroup (Trachypithecus cristatus). 3D scans of the left scapula were taken using an HDI structured light scanner and 5 landmarks and 61 sliding semilandmarks were applied to the scans to capture overall form. Following Procrustes superimposition, Canonical Variates Analysis (CVA) was performed and Procrustes coordinates were extracted and used for a Discriminant Function Analysis (DFA). The results of the CVA showed clear differences between Trachypithecus and macaques, as well as between M. fuscata and M. radiata and all other macaques. In the cross‐validated DFA, only 34.1% of individuals were correctly classified. The outgroup Trachypithecus showed a correct classification rate of 70%, as did M. nigra consistent with relatively distinct morphology in this taxon. Overall, patterns of morphological variation observed in the CVA do not match phylogenetic history, therefore suggesting environmental factors might influence the pattern of morphological variation among macaque species in novel ways, though this remains to be tested.Support or Funding InformationThis research is supported by a National Science Foundation Grant (NSF BCS‐1830745), Field Museum Visiting Researcher Fellowship, Primate Research Institute Cooperative Research Grant, University at Buffalo Asian Studies Grant, and the Mark Diamond Research Fund (SP‐18‐13).
Determining the Impact of Increased Physical Activity on Improving Sleep Quality in Young Adults
Authors: Darling Ashley , Chiu Alex , Henderson Eric , Autler Aaron S. , Weggen Jennifer B. , Decker Kevin P. , Garten Ryan S. 
Published: April 2020

Disturbed sleep, defined as any alteration to normal sleep patterns, has been linked to poor cardiovascular health and an increase in cardiovascular disease (CVD) risk. These negative sleep patterns are highly prevalent with 35% to 41% of individuals in the United States reported some form of disturbed sleep. Although high amounts of physical activity (PA) are often associated with high sleep quality, little is known about PA’s effectiveness to improve different aspects of sleep (e.g. duration vs quality) and the mechanisms to which it can improve sleep quality.PurposeThe study sought to determine the ability of increased PA to improve sleep efficiency in healthy young adults.MethodsNineteen young adults (25±4 yrs) were recruited for this study. Subjects wore an accelerometer (Actigraph GT3x‐BT) for a total of three weeks to record daily physical activity (step count; low, moderate, and vigorous physical activity) and sleep variables (efficiency, wake after sleep onset, number of nightly awakenings, time per awakening, and total sleep time). Subjects maintained normal physical activity levels for the first week (BL), then increased their step count by an average of 5,000 steps/day across the next two weeks (W1 and W2). Heart rate variability (HRV) and venous blood draws were collected weekly to assess sympathetic activity and inflammation, respectively.ResultsThe physical activity intervention resulted in significant increases (p < 0.001) in step‐count
for both W1 (13163 ± 3184) and W2 (12168 ± 3619) when compared to BL (8648 ± 2615 steps/day). No significant differences from BL were observed when examining sleep efficiency (BL: 83.8 ± 6.4; W1: 85.5 ± 4.0; W2: 84.2 ± 6.1 %), sympathetic‐vagal balance, and inflammatory marker concentrations in W1 and W2. A significant correlation was revealed when assessing the change in sleep efficiency from BL to W1 (r = 0.81, p < 0.001) and BL to W2 (r = 0.52, p = 0.02) when compared to initial sleep efficiency values.ConclusionThis study revealed that although young healthy individuals appear to lack improvements in sleep efficiency with an increase in physical activity, those who reported the lowest sleep quality had the greatest improvements in sleep efficiency following an increase in physical activity. Therefore, the findings of the study suggest that although increasing physical activity can improve sleep quality, a potential “ceiling effect” may occur, as when sleep quality is adequate, augmenting physical activity no longer has a substantial effect.
Investigation of G protein‐coupled receptor kinase 2 (GRK2) regulation of D2 dopamine receptor signaling: effects of GRK2 functional domains and pharmacologic and genetic inhibition of GRK2 activity
Authors: Schardien Kayla Anne , Soto Marta Sanchez , Inbody Laura , Berchiche Yamina , Kehrl John H. , Bradfield Clinton , Free R. Benjamin , Sibley David R. 
Published: April 2020

The D2 dopamine (DA) receptor (D2R) signals through two major pathways, namely activation of G proteins and recruitment of β‐arrestin. Agonist binding stabilizes a receptor state that activates G proteins and facilitates receptor phosphorylation by one or more members of the G protein‐coupled receptor kinase (GRK) family, and this phosphorylation is known to enhance β‐arrestin recruitment and initiate the process of internalization for many GPCRs. Previously, we found that only GRK2 and GRK3 were involved in D2R phosphorylation in response to agonist stimulation (Namkung et al., JBC: 284: 15038, 2009). In this study, we further investigated the influence of GRK2 on receptor signaling, β‐arrestin recruitment, and internalization of the D2R. Overexpression of GRK2 was found to increase DA‐stimulated β‐arrestin recruitment and receptor internalization, whereas it suppressed D2R‐mediated inhibition of cAMP accumulation. In contrast, a catalytically inactive GRK2 mutant (GRK2‐K220R) did not affect any of these functional outputs suggesting that GRK2 kinase activity is required to influence D2R signaling. A disabling mutation of the GRK2 RGS homology (RH) domain (GRK2‐D110A) behaved similarly as WT GRK2, suggesting that this domain is not required for GRK2’s regulatory effects on the D2R. Finally, overexpression of a GRK2 construct containing a mutation in the pleckstrin homology (PH) domain (GRK2‐R587Q), which negates GRK2 interaction with Gβγ subunits, increased DA‐stimulated β‐arrestin recruitment and receptor internalization (more than observed with WT GRK2), but did not affect D2R regulation of cAMP accumulation, indicating that this GRK2 domain is involved in regulating some, but not all, aspects of D2R signaling. To study D2R regulation in the complete absence of GRK2, we utilized a cell line in which GRK2 expression was knocked out using CRISPR‐Cas9 technology. DA‐stimulated β‐arrestin recruitment and receptor internalization were decreased, but not eliminated, in the GRK2 KO cells suggesting that, while GRK2 may be facilitatory, it is not essential for these processes. In parallel studies we characterized the effects of Compound 101, a dual GRK2/3 inhibitor. Compound 101 was found to negate GRK2 interactions with the D2R and attenuate, but not eliminate, β‐arrestin recruitment and receptor internalization. In contrast, in the GRK2 KO cells, Compound 101 had no effect on the residual DA‐stimulated β‐arrestin recruitment. In conclusion, our data suggest that different GRK2 domains affect specific regulatory pathways of the D2R and that both agonist‐induced β‐arrestin recruitment and receptor internalization can occur in the absence of GRK2 interactions with the D2R.Support or Funding InformationNINDS Intramural Research Program
Melatonin Prevents 1A Phase Ventricular Fibrillation in Porcine Acute Myocardial Infarction Model
Authors: Azarov Jan , Bernikova Olesya , Ovechkin Alexey , Mikhaleva Natalia , Khramova Daria , Tsvetkova Alena 
Published: April 2020

IntroductionVentricular fibrillation (VF) is a frequent complication of acute myocardial ischemia. Its prevention necessitates development of an antiarrhythmic cardioprotective strategy, and melatonin is considered to be a candidate antiarrhythmic agent. Though mechanisms of its action are largely unclear, generation of reactive oxygen species are thought to be its probable target. The objective of the present study was to find out an electrophysiological parameter subject to modification by melatonin and associated with VF incidence.MethodsAcute ischemia was induced in 25 anesthetized pigs by a 40‐min ligation of the left anterior descending coronary artery. After tightening the ligature, 12 animals were given melatonin (4 mg/kg, i.v.) and 13 placebo (control group). Intramyocardial unipolar electrograms were led from flexible electrodes (a total of 48 leads) positioned across ventricular walls and interventricular septum (IVS). Local activation times (AT, dV/dt min during QRS), end of repolarization times (RT, dV/dt max during T wave) and activation‐repolarization intervals (ARI, difference between RT and AT) were measured. After experiments, the hearts were excised, and parameters of oxidative stress were determined in the ischemic and nonischemic zones of ventricular myocardium.ResultsIn the control group, VFs were typically clustered during occlusion in 1A (1–5 min, 4 episodes) and 1B (17–40 min, 4 episodes) phases. Melatonin prevents development of 1A VFs (0 episodes, p=0.016) but did not modify occurence of 1B VFs (4 episodes). In the base of IVS (border ischemic zone), ATs in the period corresponding to 1A phase arrhythmias were shorter in the melatonin group as compared to the control group (Mean ± SD: 22±11 ms vs 39±18 ms, p=0.026, respectively) and were associated with VF incidence (OR 1.05 95% CI 1.01–1.10, p=0.023), while parameters of ventricular repolarization and oxidative stress did not differ between the treated and untreated animals.In conclusion, melatonin treatment improves conduction in the border ischemic zone and thereby prevents early ischemic VFs independently of oxidative stress development.Support or Funding InformationThe study was supported by Russian Science Foundation (RSF 18‐15‐00309).
Cerebrovascular Reactivity in Young Adults with Major Depressive Disorder
Authors: Richey Rauchelle E. , Akins John D. , Campbell Jeremiah C. , Saunders Erika F.H. , Brothers R. Matthew , Greaney Jody L. 
Published: April 2020

Cerebral vasodilatory responsiveness is blunted in older adults (~70 yrs) with depressive disorders and thought to contribute to the link between depressive symptomology and increased risk for neurocognitive (e.g., dementia) and cerebral vascular (e.g., stroke) diseases. In young adults with major depressive disorder (MDD), peripheral vascular endothelial dysfunction is evident; however, to date, limited investigations have examined cerebral vasodilatory function in young otherwise healthy adults with MDD. We tested the hypothesis that cerebral vasodilatory responsiveness to a hypercapnic stimulus would be blunted in otherwise healthy young adults with MDD compared to healthy non‐depressed adults (HA). Four HA (22±2yrs) and 6 adults with MDD (23±2yrs; n=2 tested during a major depressive episode) participated. Beat‐to‐beat mean arterial pressure (MAP; finger photoplethysmography), middle cerebral artery blood velocity (MCAv; transcranial Doppler ultrasound), internal carotid artery (ICA) diameter and blood flow (Doppler ultrasound), and end‐tidal carbon dioxide concentration (PETCO2; capnograph) were continuously measured during baseline (i.e., normocapnia) and rebreathing‐induced hypercapnia. Cerebral vascular conductance index (CVCi=MCAv•MAP−1) and ICA blood flow (Vmean•π(d•20−1)2•60) and conductance (CVC=ICA blood flow•MAP−1) were calculated at baseline and at the highest common magnitude of hypercapnia achieved by all subjects during rebreathing (ΔPETCO2 = 9 Torr). At baseline, there were no differences in any outcome variable between groups (all p>0.05). During hypercapnia, there were no group differences in the increase in MAP (Δ3±3 HA vs. Δ3±4 mmHg MDD; p=0.98). The increase in MCAv was blunted in adults with MDD (Δ33±4 HA vs. Δ23±7 cm•s−1 MDD; p=0.03). Both the absolute (Δ0.30±0.02 HA vs. Δ0.20±0.07 cm•s−1•mmHg−1 MDD; p=0.01) and relative (Δ42±7 HA vs. Δ26±9 %baseline MDD; p=0.01) increase in CVCi during hypercapnia were reduced in adults with MDD. There were no group differences in ICA diameter (Δ−0.04±0.22 HA vs. Δ0.05±0.17 mm MDD; p=0.51) or blood flow responses (Δ143±20 HA vs. Δ127±95 mL•min−1 MDD; p=0.49). Although the dilatory response in the ICA was ~50% less in adults with MDD, the increase in CVC was not significantly different between groups (Δ51±26 HA vs. Δ27±22 %baseline MDD; p=0.17). In adults with MDD, there was no relation between habitual physical activity and cerebral vasodilatory responsiveness (R2=0.09; p=0.57). These preliminary data suggest that cerebral vasodilatory reactivity to a hypercapnic stimulus may be blunted in young otherwise healthy adults with MDD, providing further support for the potential mechanistic link between cerebrovascular dysfunction and depression in increased neurocognitive and cerebral vascular disease risk.Support or Funding InformationHL133414 (JLG)