bluuebunny/crossref_metadata_2025_split huggingface dataset:
Skeletal Muscle Oxygen Uptake Dynamics during the Exercise Off‐Transient
Authors: Behnke Brad J , Ferreira Leonardo F , Musch Timothy I , Poole David C 
Published: June 2021

The time course of muscle V̇O2 recovery (i.e., muscle V̇O2 kinetics) from contractions, measured at the site of O2 exchange i.e., in the microcirculation, is unknown. It is known that, in the rat spinotrapezius muscle, blood flow (Qm) kinetics are slower in recovery (time constant, t ~41 s) than at the onset of contractions (t ~17 s, Ferreira et al. J. Physiol. 2006).PurposeWe tested the hypothesis that this Qm kinetics profile was associated with a slowed m V̇O2 recovery compared with that seen at the onset of contractions (t ~23 s, Behnke et al. Resp. Physiol. 2002).MethodsMeasurements of capillary red blood cell flux and microvascular PO2 (PO2) were combined to resolve the time course of muscle V̇O2across the moderate intensity contractions‐to‐rest transition.ResultsContrary to our hypothesis, in recovery muscle V̇O2 began to decrease immediately (i.e., time delay 0 s in all but one animal) and demonstrated rapid first order‐kinetics (t 22.4 ± 2.1 s).ConclusionsThe slowed Qm kinetics in recovery serves to elevate the Qm/ V̇O2 ratio and thus microvascular PO2. Whether this Qm response is obligatory to the rapid muscle V̇O2 kinetics and hence speeds the repletion of high‐energy phosphates by maximizing conductive and diffusive O2 flux is an important question that awaits resolution. Support NIH AG031327.
Thymic Stromal Lymphopoietin (TSLP) and Airway Smooth Muscle
Authors: Smelter Dan , Thompson Michael , Meuchel Lucas , Townsend Elizabeth , Ryu Alexander , Pabelick Christina , Vassallo Robert , Prakash Y S 
Published: June 2021

TSLP is a newly‐identified cytokine thought to be involved in airway inflammation. TSLP levels have been shown to significantly increase in airway smooth muscle (ASM) with chronic obstructive pulmonary disease and other inflammatory diseases. This study evaluated the expression of TSLP in human ASM cells and tissues exposed to cigarette smoke extract (CSE) or to pro‐inflammatory cytokines TNF‐α and IL‐13. In parallel studies, TSLP expression was evaluated in house dust mite sensitized mice with or without cigarette smoke exposure. The presence of TSLP and TSLP‐receptors were verified using Western blot analysis. Exposure to TNF‐α and IL‐13 (50 ng/mL each) for 24 hours resulted in increased TSLP and TSLP‐R expression. Simultaneous exposure to functional TSLP antibody blunted cytokine induced TSLP‐R expression. Interestingly, acute CSE (30 min) down‐regulated TSLP expression, while chornic exposure increased expression. Similarly, [Ca2+]i responses of human ASM to histamine were blunted with chronic CSE exposure, effects reversed by TSLP and TSLP‐R antibodies. Sensitized mice demonstrated an increase in TSLP expression in whole lung samples. This effect was even further enhanced in dust mite sensitized mice exposed to chronic cigarette smoke. These results indicate a complex role for TSLP in ASM inflammation with or without cigarette smoke exposure.Supported by NIH grants HL088029, HL090595, RR024150, and the Flight Attendants Medical Research Institute (FAMRI). Additional funding from the Department of Anesthesiology, Mayo Clinic.
Imatinib mesylate presents a cytostatic effect on B16 cells in vitro and an apoptotic outcome in melanoma in vivo.
Authors: Pirraco Ana , Coelho Pedro , Rocha Ana , Costa Raquel , Soares Raquel 
Published: June 2021

Melanoma is characterised by a general expression of platelet‐derived growth factor (PDGF) and its cognate receptor and by the down‐regulation of c‐Kit as the malignant potential increases. PDGF is also a powerful growth factor with autocrine and paracrine effects within melanoma. Both receptors are protein tyrosine kinases shown to be inhibited by imatinib mesylate.The aim is to investigate the effect of imatinib in melanoma cells in vitro and in vivo.Culture of B16 cells were incubated with imatinib either in the presence or absence of recombinant PDGF‐AA and assayed for proliferation (BrdU incorporation assay), apoptosis (TUNEL assay) and invasion (Double‐Chamber assay). C57BL/6 mice injected subcutaneously with B16 cells were treated daily with 100mg/Kg imatinib mesylate (n=10) or saline solution (n=6) for 2wk. Paraffin‐embedded tumour tissues were analysed for proliferation and apoptosis.Results suggest that imatinib has an inhibitory effect on the proliferation and migration of melanoma cells with no significant increase in apoptosis. However, besides preventing proliferation, imatinib strongly induces apoptosis within the tumor.In conclusion, these distinct in vitro and in vivo findings suggest that tumor cell behaviour is influenced by the action of imatinib in the tumor microenvironment. (supported by Novartis Farma, Portugal)
Modulation effect of catechin in angiogenesis and inflammation
Authors: Negrão Rita , Moura Liane , Duarte Delfim , Silva Rafael , Soares Raquel 
Published: June 2021

Inflammatory process is closely related to angiogenesis. Diets rich in plant‐derived polyphenols seem to protect from pathologies which present angiogenesis and inflammation in common. Catechin (Cat) is an abundant polyphenol. The aim of this study was to investigate the effect of Cat in angiogenesis and inflammation. Human umbilical vein endothelial cell (HUVEC) and human aortic smooth muscle cell (HASMC) were treated with 0.01‐100 µM Cat for 24 h. Cat increased viability (MTT) and decreased apoptosis (TUNEL) and proliferation (BrdU assay) in both cell lines. It decreased invasion capacity (double‐chamber assay) of HASMC while increasing it in HUVEC. Cat treatment led to a slight reduction in HASMC cell migration (injury assay) and increased HUVEC migration in the same conditions. Incubation of HUVEC on Matrigel‐coated plates with 10 µM Cat led to the formation of ramified cord‐like structures while 100 µM did not change the number of these structures. 100 µM Cat did not change the vessel sprouting capacity (aortic ring assay). Cat treatments diminished NO released to the extracellular medium but did not change the activity of NFkB. Cat interferes with some steps of angiogenic and inflammatory process but in vivo experiments are needed in order to confirm these properties.Supported by ERAB (EA0641), FCT (SFRH/BD/41888/2007) and iBeSa (BLSAD‐01/08, BLSAD‐2‐JUL/08)
A multiscale computational model of microcirculatory vasoreactivity: Linking subcellular events to macroscale responses in health and disease
Authors: Kapela Adam , Gadkari Tushar , Tsoukias Nikolaos M. 
Published: June 2021

Microcirculatory tone is regulated by an elaborate system of intracellular and intercellular signaling pathways. We developed an integrated mathematical model to elucidate how this regulation emerges from the nonlinear interaction of individual cellular components and mechanisms. Detailed descriptions of calcium dynamics and membrane electrophysiology in isolated endothelial and smooth muscle cells are validated against subcellular‐ and cellular‐level data. A multicellular vessel segment is formulated by integrating individual cells and accounting for intercellular communication. The passive and active biomechanical properties of the vessel are accounted in simulating diameter changes. The model can simulate pressure‐induced diameter changes and myogenic tone, agonist‐induced vessel constrictions and relaxations, and conducted vasoreactivity. The model also predicts altered vascular reactivity from cellular changes reported in pathological conditions. Thus, the model was successful in integrating cellular mechanisms to describe vasoreactivity and is useful for relating reported changes in subcellular components to physiological responses in health and disease.[Supported by AHA grant NSDG043506N and NIH grant HL095101]
Transcriptional analysis of skeletal muscle adaptations to marine life in king penguin juveniles (Aptenodytes patagonicus)
Authors: Dégletagne Cyril , Rey Benjamin , Keime Céline , de Dinechin Marc , Rouanet Jean Louis , Roussel Damien , Duchamp Claude 
Published: June 2021

King penguin chicks, that are strictly terrestrial during first year after hatching, must depart to sea to reach nutritional emancipation. Juvenile survival therefore depends on their adaptation to the energetic challenges of marine life: 1) harsh thermal environment, 2) long distant food resources, 3) repeated, deep and prolonged nutritional divings.To elucidate these adaptations, the transcriptome of pectoralis muscle, the main thermogenic and locomotor tissue, was analysed in juveniles that had never been to sea (n=4) and in naturally adapted juveniles (n=3) by using chicken Affymetrix DNA chips (Profilexpert, Lyon).Results showed the differential expression of nearly 3600 genes after marine life. Genes encoding enzymes of carbohydrate metabolism were down regulated while those encoding lipid transport and catabolism were up regulated suggesting an increased use of lipids as energy substrates. Further, transcripts encoding enzymes involved in cellular defense against reactive oxygen species and the associated injuries were also up regulated, suggesting an adaptive response against oxidative stress.This study opens large perspectives to elucidate how king penguins can survive in an energetically unfavorable and pro‐oxidative environment and what contributes to their remarkable longevity.This study received the financial support of the French Polar Institut (IPEV).
Selective blockade of the vasoactive intestinal peptide (VIP) receptors affect formation and development of coronary arteries in quail embryonic heart
Authors: Krieger Tatyana , Dedkov Eduard I 
Published: June 2021

We have previously demonstrated that VIP receptors are morphogenic modulators of embryonic coronary vessel tube formation in vitro. This study tested the hypothesis that a selective blockade of VIP receptors will affect formation and development of the coronary vessels in vivo. At embryonic day (ED) 5, 6, 7, and 8, a selective VIP receptor antagonist, VIP (6‐28), was injected in ovo into the vitelline vein of the Japanese quail embryos at a final concentration of 10 µmol/L. Six embryos per each ED were sacrificed 4 days after the injection and the base of their hearts was fixed in 4% paraformaldehyde/PBS, and processed for frozen or paraffin‐embedded histological cross‐sections. The serial sections through the origin of the coronary vessels were studied by H&E staining or by immunostaining with the antibodies against α‐smooth muscle actin and quail endothelium (QH1). We found that the blockade of VIP receptors did not alter the formation of left and right coronary arteries in all experimental embryos. However, when the injection was done on ED8 (the time when multiple endothelial channels penetrate the aortic wall in all three aortic sinuses), an additional coronary artery originating from a non‐coronary sinus had been detected on ED12. Furthermore, the embryos from this experimental group showed a delay in the maturation of the tunica media of coronary arteries. Our findings demonstrate that VIP receptors are involved in morphogenic modulation of coronary artery development in the embryonic quail heart.Grant Funding SourceStart‐up funding
CT comparative study of the nasolacrimal angle as a surrogate measure of prognathism in primate and non‐primate species
Authors: Gregg Michael , Palma Douglas , Delman Bradley N. , Marquez Samuel 
Published: June 2021

Previous studies suggested the path of the nasolacrimal duct (NLD) to be strongly influenced by the shape of the skull. While other studies have focused on intra‐species variation, this comparative study used a wide spectrum of mammalian species that include human, Old World monkeys, domesticated cow, pig and four dogs. Normal and CT with contrast studies were performed on the human and dog sample with patients presenting with normal and pathologic nasal conditions. The course of NLD was charted radiographically with gross dissections made upon the other cadaveric material. External NLD angle was determined by the intersection of a line that overlapped NLD path to the line represented by hard palate. Results showed non‐primate species (NPS) exhibited the largest positive NLD angles reaching values of positive 140o versus negative 37 o seen in humans. The highly prognathic NPS groups has a NLD that passes through the lacrimal bone ‐ maxilla‐ but can rostrally emerge from its bony canal deep to the nasal mucosa at various openings in the nasal region ‐ cow and pig opening occurs near mucocutaneous junction of nares; dog occurs near ventral nasal meatus. Primates presented with a NLD common drainage opening at the inferior meatus probably due to the relative prognathic reduction shared among this group. Results suggest that NLD angles may be used for determining the degree of prognathism exhibited in living and extinct primates.Grant Funding SourceDo not have funding.
FoxO1negatively regulates sterol regulatory element binding protein‐1c (SREBP‐1c) gene
Authors: Deng Xiong , Howell George , Yellaturu Chandrahasa , Wilcox Henry , Park Edwards , Raghow Rajendra , Elam Marshall , Unterman Terry 
Published: June 2021

The induction of genes involved in lipid biosynthesis by insulin is mediated in part by the sterol regulatory element‐binding protein‐1c (SREBP‐1c) and this effect is mediated in part through a mechanism that is dependent on the liver X receptor alpha (LXRα). FoxO1, a forkhead box class‐O transcription factor, is an important target of insulin action. We performed experiments to study the effects of FoxO1 on SREBP‐1c gene expression. Our studies show that over‐expression of constitutively active FoxO1 protein (CA‐FoxO1) inhibits, and small interference RNA against FoxO1 enhances both basal and insulin‐stimulated activity of the rat SREBP‐1c promoter. CA‐FoxO1 suppresses the activities of the SREBP‐1c promoter in a dose‐dependent fashion, and antagonizes the effect of insulin and TO901317 (a synthetic ligand of LXRα) on promoter activity. CA‐FoxO1 significantly reduces the effect of LXRα ?on basal and TO901317‐stimulated activity of a luciferase reporter construct driven by 3 LXR‐response elements, and decreases the transactivational ability of a Gal4‐LXRα fusion protein. These results indicate that FoxO1 plays an important role in regulating basal and insulin‐stimulated SREBP‐1c promoter activity and may exert this effect by antagonizing the function of LXRα.This work was supported by a grant from the Office of Research and Development, Department of Veterans Affairs.
PROX1 regulation of endothelial cell cycle progression
Authors: Baxter Shannon A , Herbert Krista , Kim Hae‐Kwang , Cheung David Y.C. , Wigle Jeffrey T. 
Published: June 2021

The homeobox transcription factor PROX1 is necessary for proper lymphatic vessel development. PROX1 upregulates the expression of CYCLIN E1 in both Drosophila melanogaster and mammalian cells. Expression of CYCLIN E1 is controlled by two E2F sites located on either side of the transcriptional start site. We have shown that PROX1 activates a 1 kb Cyclin E1 promoter via a DNA‐binding independent mechanism that requires both E2F sites.We used reporter gene assays to assess PROX1 regulation of Cyclin E1 promoter versions in which the E2F sites were mutated. We infected Human Umbilical Vein Endothelial Cells (HUVEC) with adenovirus encoding PROX1, and used bromodeoxyuridine, proliferating cell nuclear antigen and phosphorylated histone H3 staining to quantify changes in cell cycle progression. We used western blotting to measure protein levels of CYCLIN E1.We observed a decrease in the ability of PROX1 to activate a 206 bp Cyclin E1 promoter when either E2F site was mutated. We noted an increase of CYCLIN E1 in PROX1 infected HUVECs as well as an increased number of cells in S phase. In contrast, there was not a corresponding increase of cells in M phase.We have established that both E2F sites are essential for PROX1 mediated activation of the Cyclin E1 promoter. Our studies have discovered a novel role for PROX1 as a transcriptional co‐activator.The National Cancer Institute of Canada and the Manitoba Health Research Council support this project.
Study of spinal cord cells interactions in a tissue‐engineered three‐dimensional in vitro model
Authors: Beaulieu Marie‐Michèle , Grenier Myriam , Berthod François 
Published: June 2021

Amyotrophic lateral sclerosis and other motor neuron diseases are very complex as their development and progression involve many cellular processes and many cell types. To better understand motor neuron physiology in defined culture conditions and in a physiological environment that reflects the in vivo situation, we developed in vitro a three‐dimensional tissue‐engineered spinal cord model. Our aim was to use this model to study the pathogenesis of neurodegenerative diseases affecting motor neurons. Purified mouse spinal cord motor neurons, astrocytes and microglia were seeded on a biomaterial populated with fibroblasts that mimicked the connective tissuethrough which motor axons have to elongate in vivo. Motor neuron axon elongation and the interactions with the glial cells were assessed by immunohistochemistry after 14 days of culture. Our reconstructed tissue promoted the survival, neurite elongation and maturation of motor neurons. This tissue‐engineered spinal cord model is well‐suited to study motor neurons in vitro in a physiological three‐dimensional environment to better understand neurodegenerative diseases.
A Rodent Model to Evaluate the Effect of Dietary Protein on Intestinal Calcium Absorption
Authors: Gaffney‐Stomberg Erin , Cucchi Carrie E. , Sun Ben‐hua , Simpson Christine A. , Kerstetter Jane E. , Insogna Karl L. 
Published: June 2021

In humans, increasing dietary protein increases intestinal Ca absorption. To further study this effect, rats were randomly assigned to consume a control (20%), low (5%) or high (40%) protein diet for 7 days. All diets were isocaloric and contained 0.45% Ca, 0.35% P. Twenty‐four hr urines, blood and feces were collected to assess Ca metabolism, Ca balance and bone turnover. Brush border membrane vesicles (BBMV) were prepared from duodenal mucosa to measure Ca transport.Urine Ca rose during the high protein diet and fell during the low diet (p<0.01). There were no changes in serum Ca or vitamin D metabolites on any diet. Serum PTH trended higher in the low protein group (p=0.07) and serum osteocalcin was significantly higher compared to the other groups (p<0.03). Rats consuming the high protein diet absorbed and retained more Ca compared to the low protein group (48.5% vs. 34.1% and 45.8% vs. 33.7% respectively, p<0.01). Ca transport was significantly higher in the BBMV from animals consuming the high protein diet (p<0.001).This animal model recapitulates the findings in humans in that changes in Ca absorption explain the changes in UCa. The higher osteocalcin and PTH during the low protein diet suggest that bone turnover was increased during low protein intake. The BBMV studies indicate that increased transcellular Ca uptake contributes to the increase in Ca absorption during the high protein diet.
γ‐tocopherol supplementation improves postprandial vascular endothelial function in lean and obese men
Authors: Mah Eunice , Diaz Manuel Matos , Kawiecki Diana , Volek Jeff S , Bruno Richard 
Published: June 2021

Acute hyperglycemia is associated with oxidative stress and impaired vascular endothelial function (VEF). Thus, we hypothesized that postprandial hyperglycemia would impair VEF by affecting plasma antioxidants. In a randomized, crossover study, lean and obese men (n=8/group) followed their usual diet or were provided γ‐tocopherol (γ‐T)‐rich capsules (500 mg/d, 5 d) prior to a fasting 75 g oral glucose challenge. Flow‐mediated dilation (FMD), plasma glucose, insulin, and antioxidant capacity were measured before and during the 3 h postprandial period. Insulin resistance (HOMA) was greater in obese (6.7±3.5) than lean men (3.9±2.0, p<0.05) and unaffected during the study. Postprandial FMD area under the curve (AUC) of obese men was 32% lower (p=0.02) than lean men. FMD AUC was 31% (p=0.006) higher in all men post‐γ ‐T supplementation relative to the control trial. Baseline oxygen radical absorbance capacity (ORAC), but not ferric reducing ability of plasma (FRAP), was lower (p=0.039) in obese compared to lean men. Postprandial FRAP, but not ORAC, was higher (p=0.027) with γ‐T supplementation regardless of group. These data suggest that obesity impaired VEF and that γ‐T‐rich vitamin E supplements improve VEF possibly by enhancing antioxidant capacity. Additional study is underway to define the protective effects of γ‐T on VEF. Support provided by a grant from International Life Sciences Institute to RSB.Grant Funding SourceInternational Life Sciences Institute
Effect of different green tea formulations on diabetes in the Zucker Diabetic Rat
Authors: Myracle Angela Denise , Madian Ashraf , Burgess John R , Ferruzzi Mario , Regnier Fred , Janle Elsa 
Published: June 2021

Chronic diseases such as Diabetes mellitus (DM) are associated with increased levels of oxidative stress which is thought to contribute to secondary complications. Oral consumption of GT has been shown to have modest effects on reducing body weight, food intake and blood glucose. Simulated in vitro digestion studies have demonstrated that GT catechins can be stabilized by ascorbate which may improve bioavailability. This study investigated the effects of formulated GT on blood glucose, insulin, body weight, food consumption, and oxidized proteins in the Zucker diabetic rat (ZDF). Four groups were dosed orally with water (control), ascorbic acid (17 mg/kg), GT (85 mg/kg) or GT and ascorbic acid (85 mg/kg + 17 mg/kg) for 6 weeks. Data collected included glucose tolerance tests (GTT), daily weight and food consumption. Plasma oxidized proteins were identified and quantified to determine the potential benefit of GT to alleviate oxidative stress. Both GT treated groups showed a trend toward lower basal glucose, peak glucose concentrations and area under the curve compared to the control and ascorbate treatment. Insulin levels were not affected by the treatments. There were differential responses in the levels of oxidized proteins which varied by treatment.Supported by NIH, ODS and NCCAM Grant P50 AT 00477.
Dietary determinants of vitamin E status among a free‐living adult population
Authors: David Angeline B , Haddad Ella , Jaceldo‐Siegl Karen 
Published: June 2021

ObjectiveThe 2005 Dietary Guidelines for Americans identified vitamin E as one of six shortfall nutrients for adults, with a low probability of adequacy. We determined whether almonds in the diet contribute to plasma concentrations of alpha‐ and gamma‐tocopherol.MethodsEight‐one healthy subjects aged 25‐70 years were recruited for this 1‐year study. During the first 6 months subjects followed their habitual diets; in the second 6 months subjects added almonds equivalent to 15% of their total habitual energy intake. Intake was assessed using 14 random 24‐hour telephone recalls and plasma tocopherols by HPLC. Analysis of paired t‐tests and multivariate analysis were performed using Stata 8.0.ResultsPlasma alpha‐ and gamma‐tocopherol levels were significantly different between the habitual and almond‐supplemented diets (p<0.001 and p<0.05, respectively). In multivariate analysis including all food groups, vitamin E supplement use was the only significant predictor of alpha‐tocopherol during both study phases (p<0.001). When analyzed with age, sex, and adjusting for total energy intake, almond intake significantly predicted plasma alpha‐tocopherol during the habitual diet (p<0.05) but not during the almond‐supplemented diet (p=0.68).ConclusionConsuming vitamin E supplements is the only significant predictor of alpha‐tocopherol status in a free‐living adult population.