bluuebunny/crossref_metadata_2025_split huggingface dataset:
Short‐term, high‐intensity interval training (HIT) alters ATP pathway fluxes during maximal muscle contractions in humans
Authors: Larsen Ryan Godsk , Maynard Logan , Kent‐Braun Jane 
Published: June 2021

Phosphorus magnetic resonance spectroscopy (MRS) was used to examine the effects of 2 weeks of cycling training on bioenergetics of vastus lateralis in vivo. Eight healthy, untrained men (27 ± 4 yr) performed 6 sessions of HIT (4–6 bouts of 30‐s all‐out cycling). At baseline, and after the 1st and the 6th training sessions, rates of ATP synthesis from net PCr breakdown (ATPCK), glycolysis (ATPGLY) and oxidative phosphorylation (ATPOX) were measured during a 24‐s maximal voluntary isometric contraction (MVIC) in a 4T magnet. Training increased peak whole‐body oxygen uptake (36 ± 4 to 39 ± 5ml·kg−1·min−1, p=0.01) and exercise capacity (225 ± 32 to 239 ± 36 W, p=0.04) on the cycle ergometer, with no effects on total ATP production or force‐time integral during the MVIC. While ATP production through the 3 pathways remained unchanged after the first training session, 6 training sessions increased the relative contribution of ATPOX (31 ± 2 vs. 39 ± 2% of total ATP turnover, p<0.001), and lowered the relative contribution from ATPCK (49 ± 2 vs. 44 ± 1%, p=0.004) and ATPGLY (20 ± 2 vs. 17 ± 1%, p=0.03). Thus, 6 sessions of HIT alters muscle energetics, such that maximal contractions are performed with increased support from oxidative ATP synthesis and relatively less contribution from anaerobic ATP production, which may contribute to improved exercise capacity.Support: NIH K02 AG023582
Protein Targeting and Degradation Pathways are Coupled for Elimination of Mislocalized Proteins
Authors: Hessa Tara , Sharma Ajay , Mariappan Malaiyalam , Eshleman Heather , Gutierrez Erik , Hegde Ramanujan 
Published: June 2021

A substantial proportion of the genome encodes membrane proteins that are delivered to the endoplasmic reticulum by dedicated targeting pathways. Membrane proteins that fail targeting must be rapidly degraded to avoid aggregation and disruption of cytosolic protein homeostasis. The mechanisms of mislocalized protein (MLP) degradation are unknown.Here, we reconstitute MLP degradation in vitro to identify factors involved in this pathway. We find that nascent membrane proteins tethered to ribosomes are not substrates for ubiquitination unless they are released into the cytosol. Their inappropriate release results in capture by the Bag6 complex, a recently identified ribosome‐associating chaperone. Bag6 complex capture depends on unprocessed or non‐inserted hydrophobic domains that distinguish MLPs from potential cytosolic proteins. A subset of these Bag6 clients is transferred to TRC40 for membrane insertion, while the remainder are rapidly ubiquitinated. Depletion of the Bag6 complex impairs efficient ubiquitination selectively of MLPs. Thus, by its presence on ribosomes synthesizing nascent membrane proteins, the Bag6 complex links targeting and ubiquitination pathways. We propose that such coupling permits fast‐tracking of MLPs for degradation without futile engagement of cytosolic folding machinery.
Systemic enhancement of blood flow as a potential therapeutic strategy to counteract high altitude related health problems
Authors: Radiloff Daniel R. , Zhao Yulin , Shan Siqing , Irwin David , Hamilton Karyn , Schroeder Thies 
Published: June 2021

IntroductionAcute high altitude exposure leads to hypoxemia resulting in decreased exercise capacity. We hypothesize a pharmaceutical strategy to counteract tissue hypoxia by increasing cardiac output, and decreasing pulmonary vascular resistance resulting in increased oxygen transport to tissue.MethodsRats were habituated on motorized running wheels. Time to exhaust in a wheel was tested after i.p. injection of cardiotonic drug/vasodilator under hypobaric hypoxia using the Duke institutional hyperbaric facility. Exhaust was determined by behavioral endpoints. Data was analyzed using log rank test. Hemodynamic experiments were done on anesthetized animals under inspired hypoxia. Cardiovascular parameters were measured using pulse oximetry, fluid‐filled catheters, and oxygen needle probes.ResultsCombinational treatment with a cardiac stimulant and a vasodilator showed significant enhancement of exercise capacity under hypobaric hypoxia, but single compounds alone did not. Hemodynamic experiments confirmed enhanced cardiac activity after drug injection without increase of blood oxygenation levels. When given together, the drug combination appears to increase tissue oxygenation under hypoxia.ConclusionsModulation of cardiac activity and pulmonary vascular resistance appears a viable option to facilitate rapid acclimation to high altitude.
Glucocorticoid receptor signalling contributes to muscle atrophy caused by acute inflammation
Authors: Adams Olivia Joan , Haegens Astrid , Hermans Rob , Kelders Marco , Snepvangers Frank , Schols Annemie , Langen Ramon 
Published: June 2021

Skeletal muscle atrophy accompanies acute inflammatory conditions including ARDS, COPD exacerbations and sepsis, and closely correlates with increased mortality. Increased circulating glucocorticoid levels have been linked to muscle atrophy. Nevertheless, the contribution of glucocorticoid receptor (GR) signalling to muscle atrophy caused by acute inflammation remains to be elucidated. To investigate this, acute pulmonary inflammation was induced by intra‐tracheal lipopolysaccharide (IT‐LPS) installation, in muscle‐specific GR knockout (MLC‐Cre+/− GR‐LoxP) and control (GR‐LoxP) mice. Circulating corticosterone levels were increased within 24h in response to IT‐LPS. Increased expression of mRNA transcripts encoding glutamine synthetase and phosphoenolpyruvate carboxykinase, as well as Atrogin1 and MuRF1, was detected in skeletal muscle of control mice following IT‐LPS, suggestive of GR‐ and atrophy signalling. Importantly, the reduction in body and muscle weight following IT‐LPS observed in GR‐LoxP control mice, was strongly attenuated in muscle‐specific GR knockout mice. These data implicate an important role for muscle GR‐signaling in muscle atrophy following acute (pulmonary) inflammation.This study was supported by the Dutch Top Institute Pharma (project # T1–201).
Obese predicts increase in blood pressure associated with enhanced oxidative stress and inflammatory markers in young adults
Authors: Yoshida Michiko , Mori Takefumi , Takahashi Kuniko , Hirose Takuo , Kawamata Akihiro , Yoneki Yoshimi , Ito Hiroko , Ogawa Susumu , Hida Wataru , Ito Sadayoshi 
Published: June 2021

The present study was designed to determine whether obese could predict future hypertension and associated with oxidative stress and inflammation in young adults.1511 young adults, averaged 18±0.8 years old were enrolled. Subjects were divided into two groups according to BMI (above and below 25). Systolic blood pressure (SBP) was compared after two years. Urinary thiobarbituric acid reactive substances (U‐TBARS, as a marker of oxidative stress, n=1794) and monocyte chemotactic protein‐1 (U‐MCP‐1, as a marker of inflamation, n=794) excretion was analyzed in 103 young adults (obese students BMI avaraged 32.6±2.2, n=51) and non‐obese students BMI averaged 20.4±0.9, n=52).SBP was significantly increased in subjects BMI above 25 (136.7±18.4 mmHg) compared with subjects below 25 (123.7±15.8 mmHg, P<0.05). Percentage of subjects whose SBP increased after two years was higher in BMI above 25 compared with below 25. Significant increase (P<0.05) in SBP (129.3±14.8 mmHg), U‐TBARS (42.9±18.6μmol/day) and U‐MCP‐1 (35.1±15.9 pg/day) was observed in obese group compared with non‐obese group (148.6±14.5, 64.5±15.5 and 44.4±15.8, respectively).The results in the present study indicate that obese predicts increase in blood pressure after two years in young adults. Oxidative stress and inflammation were increased in obese young adults which is associated with increase in blood pressure.
The impact of Kosovo industrial pollution in activity of some enzymes in hemolymph and hepatopancreas of snail (Helix aspersa)
Authors: Gashi Agim , Bajraktari Ismet , Bislimi Kemajl , Ferizi Rrahman , Sahiti Hazbije , Mazreku Ilir , Halili Fetah 
Published: June 2021

The activity of following enzymes: AST ‐ Asparat amino‐transferase, ALT ‐ Alamin amino‐transferase, ALP ‐ Alkaline phosphatase and LDH ‐ Lactat‐ dehydrogenase has been examined in hemolymph and hepatopancreas of Helix aspersa (N=75). Snails were sampled in several localities in Kosovo contaminated with different physical and chemical pollutants. The snails of control group were taken from Gjilan region, far away from polluted area.The results of preliminary research show that enzyme activity depends on the area where snails were sampled. Compared to the control group snails, in hemolymph and hepatopancreas belonging to snails from contaminated localities the activity of ALP and AST was significantly lower while the activity of ALT and LDH higher. Significant decline in activity of ALP (P<0.01) and AST (P<0.01) is registered in hemolymph of snails taken from Mitrovica, whereas on the other hand significant increase has been noted in activity of ALT (P<0.001) in snails taken from Obiliq and of LDH in snails taken from Mitrovica (P<0.001) and Skenderaj (P<0.01). Opposite trend was noted in the activity of these enzymes in hepatopancreas of snails from different contaminated localities, especially in snails taken from Hani i Elezit and Mitrovica. This research shows that garden snail (Helix aspersa) can be used as bioindicator of complex environmental pollution effects.
Natural alcohol exposure: Is ethanol the main substrate for alcohol dehydrogenases in animals?
Authors: Julián‐Sánchez Adriana , Hernández‐Tobías Aída , Piña Enrique , Riveros‐Rosas Héctor 
Published: June 2021

In animals, three non‐homologous alcohol dehydrogenase (ADH) protein families are reported: Zn‐ADHs are zinc‐containing enzymes; type II ADHs lack metal cofactor, and Fe‐ADHs are iron‐activated enzymes. The presence of these ADHs in animals has been assumed to be a consequence of chronic ethanol exposure. The main natural source of ethanol is fermentation of fruit sugars by yeast. Therefore, if substrate availability must precede enzyme selection, then it can be expected that the enzymogenesis of ADHs began after the appearance of fleshy fruits. In this work, this possibility is discussed.Phylogenetic analyses reveal that type II ADHs suffered several duplications, all of these restricted to flies. Induction of type II Adh by ethanol exposure, a positive correlation between ADH activity and ethanol resistance, and the fact that flies and type II Adh diversification occurred in concert with angiosperm diversification, strongly suggest that type II ADHs were recruited to allow flies to exploit niches with high ethanol content.In contrast, Zn‐ADHs and Fe‐ADHs in animals appeared before land plants, independently of ethanol availability. Because these enzymes are not induced by ethanol and possess a high activity with non‐ethanol endogenous substrates, it can be concluded that their participation in ethanol metabolism can be considered as incidental, and not adaptive.Supported by DGAPA‐UNAM grant IN208510.
Dietary Habits and Degree of Satisfaction with Meal Service by Students with Visual Impairment
Authors: Chung Hyun-Jung , Park Hyun-Jung 
Published: June 2021

The purpose of this study was to provide basic data, to establish desirable dietary habits, and to give instructions for students with visual impairment. Over two hundred middle and high school students (137 boys and 107 girls) with visual impairment in Seoul, Gyeonggi Province and Incheon, were surveyed for interest in nutrients, dietary habits, taste for meal service and satisfaction with meal service. As for the general information of the subjects, many of them had low vision and lost sight in a postnatal manner. They showed huge interest in nutrients and obtained the most information about nutrition from the mass media and meal service. Students had meals regularly, yet showed irregular breakfast patterns. They held the right posture during eating, did not spill food, and were good at using a spoon and chopsticks. The biggest factor to affect their dietary habits was the family's dietary habits, which were followed by their homeroom teachers. As for the dietary habits to be improved and picky eating habits, many students were trying to correct their picky eating habits and demonstrated willingness to improve their picky eating habits. However, many students showed no interest in picky eating, suggesting that they need some education to choose variety of foods. In short, the schools should provide students with visual impairment with education to teach the importance of desirable dietary habits through the meal service, balanced nutrition for the menus of the lowest preference, and menus fit for their preference. In addition, they need to develop programs and education materials to provide nutrition counseling and education to help them with their picky eating habits and improper dietary habits due to multiple disabilities, diseases, long‐term intake of medication, and family environments.Grant Funding Source: Inha University
Insulin‐Independent Mechanisms of Action of Pre‐Meal Consumption of Whey Protein on Post‐meal Glycemic Response in Healthy Adults
Authors: Akhavan Tina , Luhovyy Bohdan L. , Brown Peter H. , Anderson G. Harvey 
Published: June 2021

Whey protein (WP) when consumed prior to a meal reduces post‐meal glycemic response (Akhavan et al, AJCN, 2010). The objective of the study was to identify insulin‐independent mechanisms of action. Healthy men received, in a randomized order, WP and glucose preloads (10 and 20 g/300 mL) and water control with paracetamol (1.5 g). At 30 min after consumption, the subjects were fed a preset pizza meal (12 kcal/ kg). Plasma concentrations of paracetamol, glucose and incretin hormones, involved in glycemic control, were measured at pre‐ (0–30) and post‐ (50–230 min) meal. Pre‐meal plasma paracetamol concentrations were reduced by WP, indicating delayed gastric emptying. Consumption of WP and glucose similarly reduced post‐meal plasma glucose but insulin was increased only after glucose preloads (p < 0.001). Associated with the lower post‐meal glycemic responses after WP were lower C‐peptide and higher GLP‐1, PYY and ghrelin (all p < 0.001), but similar amylin and GIP than after glucose preloads. These responses support the hypothesis the glycemic control after WP occurs in part by noninsulin dependent mechanisms. Thus, pre‐meal consumption of WP may be a novel strategy, comparable to pharmacological therapy e.g. sulphonylureas, for the prevention and treatment of hyperglycemia and type 2 diabetes.Grant Funding Source : Supported by Natural Sciences and Engineering Research Council of Canada‐Collaborative Research and Development and Kraft Canada Inc
Rab2 plays a role in lipid metabolism in the intestine
Authors: Chung Bomee , Schürmann Annette 
Published: June 2021

Intestinal lipid metabolism is comprised of multi‐steps of vesicle trafficking. Rab2 is localized in pre‐Golgi intermediates and required for vesicle trafficking between the endoplasmic reticulum and the Golgi. The aim of the study was to investigate the role of Rab2 in the secretion of chylomicron in the intestine. Rab2 expression was suppressed by transfection of specific siRNA in Caco‐2 cells, an intestinal in vitro model, and lipid absorption and lipoprotein production were examined. Rab2 expression was efficiently depleted by siRNA transfection for 14 days without interrupting cell differentiation. Apolipoprotein (Apo) B100 secretion was significantly lower in Rab2 siRNA transfected cells in the basal condition, but it recovered when the cells were oil‐loaded. In the same way, triglyceride secretion was slightly decreased in the basal condition, but recovered by oil‐load. Expression of microsomal triglyceride transport protein (MTTP) was not affected by Rab2 disruption. Rab6 expression was significantly increased in Rab2 siRNA transfected cells. These data suggest that Rab2 and Rab6 are involved in chylomicron secretion in Caco‐2 cells, and compensate its role each other.Grant Funding Source : Alexander von Humboldt Foundation
Metabolomics‐based investigation of cocaine‐induced disruption of lipid metabolism
Authors: Shi Xiaolei , Yao Dan , Wang Lei , Chen Chi 
Published: June 2021

Besides its psychological and behavioral effects, cocaine can also cause liver injury. Lipid accumulation in the liver is a pathological change occurred prior to cell death. However, the specific effects of cocaine on the homeostasis of lipid metabolism remain largely unknown. In this study, we conduct metabolomic analysis of serum samples from control and cocaine‐treated mice, along with histological and biochemical analyses. During 3‐day cocaine injection, hepatocytes in pericentral vein zone underwent progressive impairment. Serum transaminase activity was elevated dramatically at the 2nd day of cocaine treatment while the increase of both serum and hepatic triglyceride levels occurred at the 1st day of cocaine injection, suggesting the disruption of lipid metabolism preceded cell death in cocaine‐induced hepatotoxicity. LC‐MS‐based metabolomic analysis revealed that the accumulation of long‐chain acylcarnitines in serum, together with the imbalance between phosphotidylethanolamine and phosphatidylcholine species, contributes to the time‐dependent separation of control and cocaine‐treated mice in a multivariate model. Pretreatment of fenofibrate, an agonist of transcriptional factor PPARα that regulate fatty acid oxidation, completely reversed the increases of acylcarnitine level and transaminase activity and abolished cocaine‐induced cell death, suggesting that the inhibition of fatty acid oxidation plays an important role in the cocaine‐induced liver injury. Overall, our metabolomic investigation detected the unreported metabolic events elicited by cocaine exposure and provided novel insights on the underlying mechanism of these events.Grant Funding Source : NIH
CONJUGATED LINOLEIC ACID‐INDUCED LIPOLYSIS IN 3T3‐L1 ADIPOCYTES
Authors: Ippagunta Siri M , Barnes Kimberly M 
Published: June 2021

Conjugated linoleic acid (CLA) has caused an inconsistent increase in lipolysis in cell culture studies. The objective of this study was to determine the optimum dose, time, and serum conditions for CLA‐induced lipolysis in 3T3‐L1 cells. 3T3‐L1 cells were differentiated and serum starved overnight before pre‐loading with 3‐[H] oleic acid for 12 hrs. Cells were then treated with CLA or linoleic acid (LA) at different doses and times. Lipolysis was measured as the 3 hr release of 3‐[H] oleic acid with 0 (basal) or 10 (stimulated) μM isoproterenol. For the dose curve, cells were treated with 20, 30, 50, or 75 μM CLA or LA for 12 hrs. CLA increased basal lipolysis (P < 0.0001) compared to LA at 30, 50, and 75 μM, with the greatest difference at 50 μM. For the time course, cells were treated with 50 μM CLA or LA for 6, 12, 24, or 36 hrs. CLA increased lipolysis (P<0.0001), compared to LA at 12 and 24 hr, with maximal lipolysis occurring at 12 hrs (P<0.0001). For the effect of serum, cells were either serum‐starved or treated with delipidated or whole serum prior to treatment with 50 μM CLA for 12 hrs. Serum‐starved cells had increased lipolysis (P<0.0001) compared to cells treated with delipidated or whole serum. CLA caused an increase in lipolysis (P < 0.05) only in serum‐starved cells. CLA‐induced lipolysis in 3T3‐L1 cells is most optimal at a dose of 50 μM and at a treatment period of 12hrs when cells are serum‐starved prior to treatment with CLA.Grant Funding Source: HATCH
Effect of plant sterol esters on cardiovascular risk factors in hypercholesterolemic adults
Authors: Sauder Katherine A , Psota Tricia L , Kris-Etherton Penny M , Bagshaw Deborah , Alaupovic Peter , West Sheila G 
Published: June 2021

Daily consumption of plant sterol esters has been shown to decrease total and LDL cholesterol. We examined whether delivery of plant sterol esters in a low‐fat dairy dessert could decrease cardiovascular risk factors. We enrolled 49 hypercholesterolemic adults in a randomized, double‐blind, crossover study with 4‐week control and treatment periods. Participants consumed two 68g portions of the dessert daily, providing 2 g/d free plant sterols, and were counselled to follow the Therapeutic Lifestyle Changes diet. Lipids, apolipoproteins, cellular adhesion molecules (CAM), inflammatory markers, blood pressure, and cardiovascular reactivity to stress were assessed at baseline and after each treatment period. Total and LDL cholesterol decreased more after consumption of the plant sterol dessert compared to placebo (−6.0% vs −2.4% and −8.3% vs −2.7%, respectively, p<0.0001). Apolipoprotein A‐I increased after the plant sterol dessert (p<0.05). No significant changes were observed between treatments for HDL, triglycerides, CAM, and inflammatory markers. Blood pressure and total peripheral resistance during stress were lower following the placebo dessert compared to the plant sterol dessert (p<0.05). These results demonstrate that delivering 2 g/d of free plant sterols through a low‐fat dairy dessert for four weeks is clinically effective in reducing total and LDL cholesterol.Funding: Unilever
Dietary lipids and its effect on lipids profile in serum of growing rats
Authors: Perris Paula , Fernandez Inés , Mambrin Cecilia , Slobodianik Nora , Feliu Susana 
Published: June 2021

The objective is to analyze the effect of high fat diets on triglycerides (TG), total cholesterol (TC), HDL cholesterol and fatty acid profile of growing rats. Weanling Wistar rats were fed during 10 days: 50% dietary fat provided by butter and cocoa butter (S group); 50% dietary fat provided by olive oil and soy oil (M group). Control group(C) received normocaloric diet.Fatty acid profiles were determined by gas chromatography (GC); ω3/ω6 and unsaturated/saturated (UFA/SFA) ratios of diets were calculated. Serum levels of TG, TC and HDL were determined by enzymatic‐colorimetric method and fatty acid profile, was determined by GC (area %).Resultsω6/ω3 diets ratio: S = 8.7 / 1; OS = 15 / 1; C = 9 / 1; UFA/SFA, S = 0.54; OS = 4.2; C = 5.5. Serum (mean±SD mg/dL) TG S: 191.9±66.5; M: 98.1±49.7 ;C: 94.1±37.7; CT S: 83.8±10.9 M: 78.2±10.5 C: 81.1±14.8; HDL S: 32.9±11 M: 36.8±9.0 C: 32.9±9.5. TG levels in S were statistically higher compared to C and M (p<0.01).Serum oleic acid levels in S and M groups were higher than C (S = 20.49 ± 2.41, OS = 20.95 ± 5.14, ± 3.41 C = 11.43, p <0.01).The S diet induces high levels of TG, as a result of the type of fatty acids received more than to the high concentration of lipids. The administration of diets probably caused changes in serum levels of oleic acid in response to differences in the profile of fatty acids of the sources used and the provided percentage of fat, which would exacerbate the route of the ω9 family.