bluuebunny/crossref_metadata_2025_split huggingface dataset:
Direct PKA‐PDE interactions lead to localized cAMP signaling domains in adult cardiomyocytes (1013.7)
Authors: Boras Britton , Taylor Susan , McCulloch Andrew 
Published: June 2021

The β‐adrenergic pathway in cardiomyocytes activates protein kinase A (PKA) to phosphoregulate several Ca2+ handling proteins, including L‐type Ca2+ channels, ryanodine receptors, and sarco/endoplasmic reticulum Ca2+‐ATPases (SERCA) (via phospholamban), resulting in inotropic, lusitropic and chronotropic responses. Based on PKA kinetics measured in vitro, almost all PKA should be activated by basal concentrations of cAMP, limiting its dynamic range in response to a stimulus event. Several studies have postulated a role for local degradation of cAMP by phosphodiesterases (PDE) in maintaining microdomains with lower cAMP concentrations around A kinase anchoring proteins (AKAP), which bind both PKA and PDE. In this study we use 3‐D diffusional modeling around cell geometries from transmission electron microscopy (TEM) images to show that local clustering of PDEs is insufficient to maintain cAMP microdomains necessary for lower PKA basal activation. We instead propose a new model for PKA activation which incorporates direct binding between PDE’s and the regulatory subunit of PKA as a pathway to stimulate PDE activity and inhibit PKA activation. We used in vitro kinetic experiments with 3H tagged cAMP and purified PKA and PDE to quantify this interaction and explore its specificity both for PKA and PDE isoforms.Grant Funding Source: Supported by: NIH 5 T32 HL 105373‐2
Human p190A RhoGAP binds eIF3A and exists in a complex with the 48S translational pre‐initiation complex (1013.8)
Authors: Parasuraman Prasanna , Walker James , Li Bihua , Mulligan Peter , Haas Wilhelm , Bernards André 
Published: June 2021

By regulating the actin cytoskeleton Rho GTPases control biological processes such as cell migration, adhesion and polarity. p190A RhoGAP is an important yet poorly understood Rho GTPase regulator. To shed further light on the functions of p190A RhoGAP, we performed mass spectroscopic analysis of associated proteins. Here we report that human p190A, but not its related paralog p190B, forms a stable complex with multiple subunits of the 48S translational pre‐initiation complex. Complex formation involves a direct interaction between the first FF domain of p190A and the PCI/PAM domain of eIF3A. This interaction does not appear to be regulated by Y308 phosphorylation, previously found to control the p190A directed cytoplasmic sequestration of TFII‐I, but may instead by controlled by phosphorylation of S296 by an as yet unknown protein kinase. Although other reasons for the detected interaction cannot be ruled out, we speculate that p190A RhoGAP may serve as an anchoring protein allowing the localized translation of specific mRNAs.Grant Funding Source: RO1 GM084220
The problem with low pricing: buffet lunch and regret (1019.15)
Authors: Sigirci Ozge , Wansink Brian 
Published: June 2021

Objective: Will the price people pay for an All‐you‐can‐eat buffet influences them to overeat and to feel guilty about how much they eat? This has implications for consumers, restaurants and public health.Methods: A field experiment was conducted in which diners at an All‐you‐can‐eat (AYCE) restaurant were either charged $4 or $8 for an Italian lunch buffet. The ratings of consumers who eat different number of pieces of pizza were taken for overeating, physical discomfort, and guilt items. Their ratings were analyzed using 2x3 between groups ANOVA.Results: Consistent with expectation disconfirmation theory, diners who paid $4 for their buffet rated themselves as physically more discomfortable and has eaten more than they should have comparing to the diners who paid $8 for the buffet (p<0.05). Interestingly, even if they ate the exact same number of pieces, diners who paid $4 for their buffet rated the overeating, feeling of guilt and physical discomfort items higher than the diners who paid $8 for the buffet.Conclusions: Paying less for an AYCE experience has a number of surprising consequences.Interestingly, low‐ priced diners feel themselves as physically more discomfortable, and guiltier comparing to the low‐priced diners even if they ate exactly the same amount with high‐priced diners.
Proportionality of regional fat pattern changes with weight change (1031.14)
Authors: Davidson Robert , Gibson Glenn 
Published: June 2021

Objective. There has been some debate in the literature regarding fat pattern changes with weight change, particularly whether fat loss is proportional or if you can ‘spot reduce’. Using published papers reporting changes in regional fat due to various interventions as measured with DEXA we determined the proportionality of fat change in arm, leg, arm and leg, and trunk regions.Methods. Twenty‐three studies were identified from Pub Med searches that reported regional fat data before and after an intervention resulting in fat change (gain or loss). The initial and final percentage of total body fat occurring in each region (arms, legs, or arms and legs, and trunk) for each intervention was compared. To see if the magnitude of fat change influenced regional fat pattern changes, total body fat change was compared to the ratio of final to initial percentage of body fat in each region.Results. The average ratio of final percent of total body fat in a region to the initial percent of total body fat in the region was 0.98, 0.99, 0.99, and 1.02 for arm, leg, arm and leg, and trunk regions, respectively. Linear regression of plotted initial versus final percent of total body fat in each region gave slopes of 0.84, 0.88, 1.09, 0.80, and 1.00 for arm, leg, arm and leg, trunk, and all regions combined, respectively.Conclusions. Regional fat pattern changes are proportional to the initial percentage of body fat in each region.
Effects of mild calorie restriction on hepatic lipid metabolism and inflammation in mice (1034.14)
Authors: Park Chan Yoon , Park Soyoung , Kim Min Soo , Han Sung Nim 
Published: June 2021

Calorie restriction (CR) has been reported to improve liver adiposity and inflammation. However, most CR models use 30~60% calorie reduction, which is hard to achieve in human. We investigated the effects of mild CR on hepatic lipid metabolism and inflammation. Seven‐wk‐old C57BL/6 mice were fed control diet containing 10% kcal fat (Control) or high fat diet containing 60% kcal fat (HFD) or reduced amount of control diet to achieve 14% calorie restriction (CR). Hepatic and epididymal IL‐1, IL‐6, Mcp‐1, Tnf‐, and Socs3 mRNA, hepatic Pparg, Ppara, Fasn, Srebf‐1c, Adipor2, and Cpt1 mRNA and hepatic Sirt1 and pStat3/Stat3 protein expression levels were determined. Hepatic expression of genes related to lipogenesis, Pparg and Srebf‐1c, were significantly lower in CR compared with HFD. The mRNA levels of pro‐inflammatory cytokines Mcp‐1, IL‐6, IL‐1 and Tnf‐ in adipocyte were significantly lower in CR compared with HFD. In liver, only Mcp1 mRNA level was lower in CR than Control and HFD (63% and 74% lower). Serum leptin level was significantly lower and hepatic Lepr mRNA level was significantly higher in CR than Control. Hepatic expression of Socs3 was higher in CR than HFD (154% higher) and correlated with Lepr (r = 0.699, P <0.001) and pStat3/Stat3 ratio (r =0.596, P =0.004). In conclusion, mild CR reduced hepatic lipid synthesis, attenuated hepatic Mcp‐1 expression, and improved leptin sensitivity.Grant Funding Source: Supported by the grant from the National Research Foundation (NRF) of Korea, (NRF‐2010‐0024878).
Effect of n‐3 fatty acids and their derivatives on the expression of inflammatory genes (1034.15)
Authors: Allam‐Ndoul Benedicte , Guenard Frederic , Barbier Olivier , Vohl Marie‐Claude 
Published: June 2021

Background: Uncontrolled inflammation participates in the development of chronic inflammatory diseases. Beneficial effects of the consumption of long chain n‐3 polyunsaturated fatty acids (PUFAs), mostly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), on inflammation have been reported. Lipid mediators produced from EPA and DHA (resolvins) play a central role in the resolution of inflammation. Objective: To study the effects of EPA, DHA, resolvin D1 (RvD1) and resolvin D2 (RvD2) on the expression of inflammatory genes in cultured THP1 macrophages. Methods: Cells were incubated for 6h and 24h in the presence of n‐3 PUFAs (EPA, DHA; 100, 50, 25, 10 μM and resolvins (RvD1, RvD2; 1μM, 100, 50, 25, 10 nM). Total RNA was isolated and TNF‐alpha, IL‐6 and IL‐10 mRNA levels were analyzed by real‐time PCR. Results: In THP1 cells, EPA, DHA, RvD1 and RvD2 down‐regulated IL‐6 and TNF‐alpha gene expression, and up‐regulated IL‐10 expression in a time‐dependent manner with higher extent observed after 24h. TNF‐alpha, IL‐6 and IL‐10 gene expression demonstrated a dose‐dependent response following treatment with EPA and DHA (10, 25 and 50 μM). No association was found between gene expression and resolvins concentrations in dose‐response experiments. Conclusion: We demonstrate a time‐ and dose‐dependent regulation of TNF‐alpha, IL‐6 and IL‐10 gene expression levels in macrophages under EPA and DHA treatment.Grant Funding Source: NSERC
The effect of almond consumption on satiety and the postprandial metabolic response in high‐risk pregnant women (1040.5)
Authors: Henderson Mary , Sawrey‐Kubicek Lisa , Mauldin Kasuen , King Janet 
Published: June 2021

Over one third of all American pregnant women are obese. Managing weight gain during pregnancy is difficult because hormonal changes induce an anabolic state facilitating tissue gain. The pregnancy hormonal effects on appetite and energy intake are unknown. Almonds are satiating and have a lower net metabolizable energy, which may explain their role in managing body weight and aiding in weight loss. As well, results from a number of clinical trials have shown other health benefits of almond intake including reducing oxidative stress and inflammation and promoting vascular health and glycemic control. A cross‐over, randomized control trial examining the metabolic response to 2 oz of almond consumption versus dairy fat consumption in 2 standardized, isocaloric and equal macronutrient composition test meals, was done in 20 overweight/obese (pre‐pregnancy BMI = 25‐40) Asian and Latina women during 30‐36 weeks of gestation. Satiety was assessed by visual analogue scale questionnaires, circulating ghrelin, leptin, and GLP‐1 concentrations, and ad libitum food intake at a meal following the postprandial study. Our early data suggest that consuming 2 oz of almonds improves satiety, reduces appetite, and may help promote healthy maternal weight gain during pregnancy.Grant Funding Source: Supported by the Almond Board of California
Role of thioredoxin‐binding protein 2 in cardiac oxidative stress and energy metabolism of rats supplemented with vitamin D (1041.14)
Authors: Santos Priscila , Rafacho Bruna , Gonçalves Andréa , Pires Vanessa , Fernandes Ana Angélica , Minicucci Marcos , Azevedo Paula , Okoshi Marina , Zornoff Leonardo , Paiva Sergio 
Published: June 2021

Vitamin D (VD) is important for cardiac development and functioning but, recent studies have shown that VD receptor is undetectable in cardiac muscle. On the other hand, in the heart is present a thioredoxin‐binding protein (TBP‐2) which is up regulated by VD. The aim of this study was to evaluate whether supplementation with different doses of VD results in changes in TBP‐2 protein expression, cardiac oxidative stress and energy metabolism. Methods: 48 male rats allocated into 4 groups: control (C, n=12) received standard chow; VD3 (n=12), VD5 (n=12) and VD10 (n=12) received 3000, 5000 and 10000 IU of cholecalciferol/kg chow for 2 months. Statistical analysis was performed by ANOVA or Kruskal‐Wallis test and Test for Linear Trend. Results: The TBP‐2 protein expression was higher in VD10 group compared to control and VD3 in a dose‐dependent manner (p<0.001). In relation to the oxidative stress, the thioredoxin (Trx) protein expression decreased in dose‐dependent manner (p=0.019) and lipid hydroperoxide (LH) was higher in VD10 compared to other groups. The increase in LH was dose dependent (p<0.001). In relation to cardiac energy metabolism, the peroxisome proliferator‐activated receptor‐γ coactivator‐1 α (PGC‐1α) protein expression was lower in VD10 compared to control in dose‐dependent manner (p=0.002). Activity of the enzymes: 3‐hydroxyacyl coenzyme‐A dehydrogenase and citrate synthase was lower and lactate dehydrogenase was higher in VD10 compared to other groups. Conclusion: The increased expression of TBP‐2 in rats with VD supplementation may be associated with increased oxidative stress and changed cardiac energy metabolism in these animals.Grant Funding Source: Supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Comparison of tissue concentrations in male and female C57BL/6 mice in response to vitamin K manipulation (1041.4)
Authors: Harshman Stephanie , Smith Donald , Karl James , Shen Xiaohua , Booth Sarah , Fu Xueyan 
Published: June 2021

The tissue‐specific response to dietary vitamin K (VK) manipulation has not been well studied in mice. This limits the use of genetically modified mouse models in VK studies. The objective of this study was to determine the sex‐specific effects of dietary VK manipulation on serum, liver and extra‐hepatic tissue VK concentrations in C57BL/6 mice (n=64). Mice were weight‐matched and pair‐fed a control diet (1.4±0.08 mg phylloquinone (PK) /kg) or VK‐deficient diet (31±0.45 µg PK/kg) for 28 days. Liver, kidney, brain, pancreas, adipose tissue, and serum PK and menaquinone‐4 (MK‐4) concentrations were measured by HPLC. Data were log transformed and analyzed by a general linear model, stratified by diet. Male and female mice responded differently to dietary manipulation of VK in a tissue‐dependent manner (for all sex by diet interactions p<0.031). Serum PK concentrations did not differ between males and females within each diet (p>0.95); no serum MK‐4 was detected. Females on the control diet had significantly higher PK and MK‐4 concentrations in adipose tissue, kidney, liver, pancreas, and brain compared to males (p<0.01). Only MK‐4 concentrations in adipose tissue, liver, and pancreas did not differ between males and females on the deficient diet (p>0.44). Sex‐specific differences in response to VK manipulation need to be considered when using animal models of VK metabolism.Grant Funding Source: Supported by the USDA/ARS Cooperative Agreement No. 58‐1950‐7‐707
Ascorbate‐induced iron transport through ferroportin involves IRP2 and HIF2α (1042.2)
Authors: Scheers Nathalie , Sandberg Ann‐Sofie 
Published: June 2021

In previous studies we have shown that ascorbate status of intestinal Caco‐2 cells affects the cellular levels of iron‐absorption related proteins (DMT1, DCYTB, ferritin, and ferroportin). The aim of the present study was to dig deeper into the ascorbate effects to investigate the mechanisms behind. We have measured ferroportin, IRP2, and HIF2α expression in response to different ascorbate concentrations with ELISA and Western blot analyses, which resulted in peaking protein levels at 100 µM followed by a decrease at higher ascorbate concentrations. In conclusion, Iron‐independent regulation of ferroportin by IRP2 seems to be responsible for the ascorbate‐mediated decrease in ferroportin with increasing ascorbate status.Grant Funding Source: The Swedish Council for Environment, Agricultural Sciences and Spatial Planning funded this study.
Inhibition of digestive enzymes by tea polyphenols: enzymological and in silico studies (1045.34)
Authors: Glisan Shannon , Sae‐Tan Sudathip , Grove Kimberly , Yennawar Neela , Lambert Joshua 
Published: June 2021

Tea (Camellia sinensis) has shown anti‐obesity effects in animals. Tea polyphenols can inhibit digestive enzymes such as pancreatic lipase (PL), phospholipase A2 (PLA2), and trypsin in vitro. Our objective was to explore the mechanisms of inhibition by tea polyphenols by enzymology and in silico modeling. Theaflavin‐3,3’‐digallate (TFdiG), theaflavin‐3’‐gallate, theaflavin‐3‐gallate, and theaflavin inhibit PL with IC50 = 1.9, 4.2, 3.0, and 32.9 µM, respectively, indicating that the location of the galloyl ester is essential for inhibitory potency. TFdiG exhibits a mixed mode of inhibition. Theaflavins were found to bind to a pocket adjacent to the active site in PL; galloyl‐containing theaflavins are able to form a hydrogen bond with His264, which forms part of the catalytic triad. Similar interactions are predicted with green tea catechins. Catechins also inhibit PLA2. Modeling studies show that these compounds occupy a tunnel that leads to the active site and are stabilized by van der Waals bonds. This interaction is expected to result in noncompetitive inhibition. We found that (‐)‐epigallocatechin‐3‐gallate (EGCG) inhibited trypsin (IC50 = 193 µM) in a non‐competitive manner. Modeling studies show that EGCG interacts with amino acids around the active site and hinders substrate binding. These findings provide insight into the mechanisms by which tea polyphenols can inhibit key digestive enzymes.Grant Funding Source: NIH AT004678
Ursolic acid, a promising dietary bioactive compound of anti‐obesity (1045.40)
Authors: Wang Yanwen , He Yonghan 
Published: June 2021

Ursolic acid has recently been reported to possess a promising anti‐obesity effect. A number of studies have been conducted to elucidate the underlying mechanisms, which include the inhibition of pancreatic lipase activity, promotion of muscle hypertrophy, increase of brown fat, thermogenesis, energy expenditure, and lipolysis. Our recent study in 3T3‐L1 preadipocytes has demonstrated that ursolic acid inhibits cell differentiation and adipogenesis. This compound modulates the expression or activity of many proteins or enzymes involved in fat cell differentiation, fatty acid synthesis and oxidation. Further studies have shown that ursolic acid increases the phosphorylation and activity of AMPK and the protein expression of Sirt1. The anti‐adipogenic effect of UA can be reversed by AMPK siRNA but not Sirt1 inhibitor. Moreover, when LKB1 is silenced or inhibited, the effect of UA on AMPK activation diminishes. These results demonstrate that ursolic acid inhibits preadipocyte differentiation and adipogenesis through LKB1/AMPK pathway. While focusing on our recent report on the effect and mechanism of action of ursolic acid on fat cell differentiation and adipogenesis, other mechanisms related to energy and fat metabolism and body weight will be briefly discussed.Grant Funding Source: CIHR
Phytochemical genistein promotes pancreatic beta‐cell survival and exerts anti‐diabetic effect via GPR30‐mediated mechanism (1045.44)
Authors: Wang Aihua , Liu Dongmin , Luo Jing , Suh Kyung‐Shin , Moore Willam , Alkhalidy Hana 
Published: June 2021

Loss of pancreatic beta‐cell mass is central to the development of both type 1 and type 2 diabetes (T2D). Chronic hyperglycemia and hyperlipidemia cause beta‐cell apoptosis, thereby contributing to the pathogenesis of T2D. We investigated the effects of phytochemical genistein on apoptosis and function of beta‐cells and further determined the mechanism underlying its actions ex vivo and in vivo. We show that genistein promoted viability, inhibited apoptosis, and reduced caspase‐3 activity of INS1 beta‐cells and human and mouse islets chronically exposed to palmitate (0.5 mM) and high glucose (HG, 20 mM). In addition, exposure of beta‐cells to genistein activated PI3K/Akt signaling and up‐regulated anti‐apoptotic protein Bcl‐2 expression. The anti‐apoptotic effect of genistein is independent of classical estrogen receptor‐mediated signaling machinery, but it may be achieved through the G‐protein‐coupled receptor GPR30‐mediated activation of cAMP signaling. Oral administration of genistein (50 mg/kg BW/day) improved hyperglycemia, glucose tolerance, and blood insulin levels in wide‐type obese diabetic mice, but these effects were abolished in GPR30 null mice. These findings demonstrate that genistein exerts anti‐diabetic effect and promotes beta‐cell survival via GPR30‐mediated signaling pathway.Grant Funding Source: supported by grants from the NCCAM of NIH (R01AT007077) and the ADA (7‐11‐BS‐84) to DL.
Role of GSK3 beta and ERK in the human neutrophil response to fungal beta‐glucan (1046.5)
Authors: Johnson Courtney , Byrd Angel , Reichner Jonathan 
Published: June 2021

Complement Receptor 3 (CR3), an integrin found on neutrophils, plays an important role in the neutrophil recognition and response to fungal components in the context of extracellular matrix proteins. Co‐ligation of CR3 with fibronectin (Fn) at the I‐domain and ß‐glucan (B) at the lectin‐like domain is possible due to spatially distinct locations and creates unique cellular activity not seen with ligation of either domain separately. Dual ligation of CR3 with Fn+B induces homotypic aggregation of primed neutrophils, a response representative of the immune cells encounter with fungi within tissues. To understand the signaling pathways involved in these CR3‐mediated responses, we employed various molecular techniques to determine the key proteins. Mass spectroscopy revealed a significant increase in tyrosine phosphorylation of nineteen proteins in human neutrophil samples exposed to FN+B but not in samples exposed to FN alone. Western blotting and immunopreciptation techniques validate these findings by showing an increase in two of the proteins, p‐ERK and p‐GSK. Further work using inhibitors UO126 (ERK inhibitor) and TZDZ‐8 (GSK3Beta inhibitor), show differing effects on cluster formation. Use of UO126 caused a complete abrogation of cluster formation and a significant loss of ERK phosphorylation. However, use of TZDZ‐8 caused a partial inhibition of cluster formation with little effect on GSK3Beta phosphorylation. Blotting for protein levels, we were able to show the phosphorylation of ERK increases over time while the phophorylation of GSK decreases. Use of TZDZ‐8 decreased the phosphorylation of ERK, while inhibition with UO126 had little effect on GSK3 phosphoryaltion. This result indicates a upstream role for GSK3 Beta in the phosphorylation of ERK. In addition, monoclonal antibody blocking of CR3 led to an increase in GSK3 Beta phosphorylation indicating CR3 signaling of p‐ERK may be regulated through GSK3 Beta phosphylation.Grant Funding Source: Supported by NIH GM‐066194