bluuebunny/crossref_metadata_2025 huggingface dataset:
Does exposure to whole grain foods change explicit and implicit wanting of food categories differing in sweet/savory and low/high fat? (631.5)
Authors: De Leon Angela , Rust Bret , Horn William , Burnett Dustin , Keim Nancy
Published: June 2021

Understanding the complexity of food choice behavior has become paramount in our current obesigenic environment. Drivers of food choice include ‘liking’_the pleasure derived from tasting a food and ‘wanting’_how hard one is willing to work to acquire that food. We designed an intervention which provided whole grains (WG) to self‐reported low WG consumers (< 1 WG oz/d) to gauge the effect of WG exposure on explicit and implicit wanting for foods varying in sweet taste and fat content. Healthy adults were provided market baskets of WG products for use over 6 wk. We hypothesized that exposure to WG would change explicit and implicit wanting, by halo effect, of food categories with reduced sugar and fat content. To assess changes a computerized paired comparison test was administered pre‐ and post‐intervention. Both implicit and explicit wanting was greatest for high fat savory foods and least for low fat sweet foods (p< .0001). In this sample we were not able to detect and intervention effect on specific food categories for implicit or explicit wanting.

Grant Funding Source: Supported by USDA 5306‐51530‐019‐00D.
Modulation of CD36 scavenger receptor expression by curcumin and vitamin E affects cellular uptake of lipids and bacteria (639.1)
Authors: Zingg Jean‐Marc , Nakagawa Kiyotaka , Azzi Angelo , Meydani Mohsen
Published: June 2021

The CD36/FAT scavenger receptor/fatty acid translocase mediates uptake of fatty acids into various tissues. Other CD36 ligands include oxLDL, β‐amyloid, Plasmodium falciparum ‐infected erythrocytes, and bacteria. The ability of nutritional components to affect CD36 expression and to change the inflammatory and phagocytic response to lipids and bacteria in monocytes/macrophages could be important for modulating inflammation and atherosclerosis. Here we show that curcumin, a natural polyphenol from turmeric plant Curcuma longa, is rapidly taken up into cells and increases surface localization of CD36 leading to increased lipid uptake in THP‐1 monocytes/macrophages. The curcumin metabolite, tetrahydrocurcumin, has no effect, most likely since it is not efficiently taken up into cells. In contrast, CD36 surface localization and lipid uptake were decreased by α‐tocopherol and more so by α‐tocopheryl phosphate. Interestingly, phagocytosis of inactivated Staphylococcus aureus fluorescent bioparticles was affected by these compounds in a similar manner as observed for lipids, suggesting that binding and uptake of lipids and bacteria may share common molecular mechanisms. Thus, these dietary components may not only directly modulate the cellular anti‐microbial and inflammatory response but also indirectly by influencing host‐microbe interactions. Supported by USDA Contract #58‐1950‐0‐014.

Grant Funding Source: Supported by USDA Contract #58‐1950‐0‐014.
The effect of a high vs. low glycemic response diet on the intra‐ and extracellular redox state (641.10)
Authors: Simmons Amber , Wong Siu , Corkey Barbara
Published: June 2021

Increased consumption of processed foods is suspected to be contributing to obesity and chronic disease. We hypothesized that long‐term consumption of more processed food (mimicked with high (HGR) or low glycemic response (LGR) starches) would lead to oxidation of the circulating redox state, increased fat accumulation, and reduced insulin sensitivity. Mice consumed HGR or LGR food for 16 weeks. Body mass increased at a faster rate for those consuming the HGR diet (p < 0.05 for weeks 8‐16). Percentage body fat was greater and percentage lean mass was lower in the HGR group starting at 12 weeks (p < 0.05; MRI). However, insulin sensitivity at week 14 (OGTT; AUC, p = 0.14) and metabolic parameters (RER, heat production, activity) at weeks 4 or 15 were not significantly different between groups. At the termination of the study, redox pairs (L/P, B/A) suggested a more oxidized redox state in blood of mice on the LGR diet. TrxR activity in blood and TBARS of blood and liver tissues were similar between groups (p > 0.05). These data illustrate that the mechanism by which processed carbohydrates contributes to obesity is not via oxidation of the circulating redox state.

Grant Funding Source: United States Department of Agriculture
Development of a relevant cell culture model to examine lutein absorption in vitro (645.12)
Authors: Kamil Alison , Blumberg Jeffrey , Chen C‐Y.
Published: June 2021

Lutein bioavailability is influenced by dietary fat which facilitates absorption via micelles. Permeable support systems are employed in in vitro nutrient absorption studies but data are absent on whether this approach generates results more relevant to in vivo absorption than a monolayer system (MONO). We used Caco‐2 colorectal cells to compare the efficacy of lutein uptake in a MONO and a permeable support Transwell® system (TRAN) to examine the role of micelles. After plating for 2 and 21 d to attain confluence and differentiation in MONO and TRAN, respectively, cells were treated with 4 µg/mL lutein in 0.8% ethanol or synthetic micelles. After 36 h, lutein in cell lysate and basolateral medium was quantified by HPLC. Lutein in the cell lysate after ethanol was 220% greater than after micelle solubilization in MONO (3.0 vs. 1.4 µg/mg protein) but in the TRAN, lutein after ethanol was 77% lower (0.3 vs. 1.3). In TRAN, <1% (14.6 ng) of the micellized lutein was secreted to the basolateral medium while none was detected with lutein in ethanol. Thus, differentiation and/or culture system mediate lutein uptake into Caco‐2 and micelle components facilitate the intestinal secretion of lutein. As differentiated Caco‐2 display small intestinal phenotypes, micelles appear necessary to enable lutein transport across the small intestine but lutein can move into the large intestine efficiently without this facilitation.

Grant Funding Source: Suported by USDA
FGF21 deficiency exacerbates chronic alcohol induced fatty liver disease via a p38MAPK and PGC‐1α mediated pathway (653.13)
Authors: Liu Yanlong , Zhao Cuiqing , Zhang Min , Wu Guicheng , McClain Craig , Feng Wenke
Published: June 2021

Extrahepatic hormones, such as insulin and glucagon, are important in alcohol‐induced alteration in liver lipid metabolism. However, little is known whether the paracrine and endocrine signal for metabolic regulation of hepatic itself participates in alcohol exposure associated lipid accumulation. Fibroblast growth factor 21 (FGF21) is a hepatokine and plays a critical role in the glucose and lipid metabolism in obese and diabetic animals. Here, we demonstrated that FGF21 deficiency exacerbate chronic alcoholic liver disease (ALD). Mice were fed diet containing 5% alcohol for 4 weeks. Alcohol feeding increased hepatic fatty acid and triglyceride contents and fat accumulation in WT mice, which is exacerbated in FGF21‐KO mice. The increased hepatic steatosis was accompanied by elevated liver injury evaluated by liver enzyme levels and hepatic inflammation. Hepatocyte mitochondrial fatty acid β‐oxidation was reduced, as measured by Seahorse technology, and genes involved in the β‐oxidation were down‐regulated in FGF21‐KO mice exposed to alcohol. Further studies showed that alcohol exposure significantly decreased PGC‐1α phosphorylation and p38MAPK activation in FGF21‐KO mice. In vitro study showed that recombinant FGF21 treatment increased PGC‐1α activation, the effect was diminished by p38MAPK inhibitors. In conclusion, FGF21 is likely required for cellular capacity for fat clearance in subjects exposed to chronic alcohol through PGC‐1α activation.

Grant Funding Source: Supported by NIH, DOD and Veterans Administration
Lipid‐derived aldehyde, acrolein, is a critical mediator of alcohol‐induced gut‐liver injury (653.14)
Authors: Chen Wei Yang , Zhang Jingwen , McClain Craig , Barve Shirish , Joshi‐Barve Swati
Published: June 2021

Alcohol is the most socially accepted addictive drug which leads to alcoholic liver disease (ALD), a major cause of morbidity/mortality in the United States. Chronic alcohol consumption, commonly associated with cigarette smoking, causes a pro‐oxidant environment in the liver and increases lipid peroxidation. Acrolein (ACR) is the most reactive and hepatotoxic aldehyde metabolite generated via lipid peroxidation, and is a major component of cigarette smoke. This study investigates the pathogenic role of acrolein as a major mediator of intestinal barrier dysfunction and hepatic endoplasmic reticulum (ER) stress and injury, which are recognized etiologic factors in ALD.

We examined hepatic and intestinal effects of acrolein and alcohol using in vitro (rat hepatic H4IIEC, and human intestinal epithelial Caco2 cells) and in vivo (C57/Bl6 mice ‐ chronic+binge alcohol feeding) models. ACR adducts accumulated in response to alcohol or ACR in mouse livers and intestines, and in cultured cells. This was accompanied by hepatic steatosis, activation of JNK, ER stress (upregulation of ATF3, ATF4, and pro‐apoptotic CHOP), mitochondrial disruption and apoptosis as seen by Cellomics. Notably, the cytotoxic effects of ACR and alcohol were attenuated by acrolein/aldehyde scavengers, and by an inhibitor of phosphodiesterase‐4 which regulates cellular cAMP. Alcohol‐induced in vivo intestinal effects (down‐regulation of tight junction proteins ZO‐1, occludin, and claudin, and barrier dysfunction) were mimicked by ACR in Caco2 cells. Our study demonstrates that acrolein is an important mediator of the hepatic and intestinal effects of alcohol consumption, and suggests a therapeutic potential for phosphodiesterase inhibitors and acrolein scavengers in ALD.

Grant Funding Source: Supported by NIH, DOD and Veterans Administration
Pathogenic mechanisms in highly active anti‐retroviral therapy‐induced hepatotoxicity: role of phosphodieaterase 4 and ER‐stress (653.7)
Authors: Donde Hridgandh , Barve Priyanka , Barker David , Joshi‐Barve Swati , Gobejishvili Leila , McClain Craig , Barve Shirish
Published: June 2021

HIV protease inhibitors (HIV‐PIs) are the major components of HAART and have been successfully used in the treatment of HIV‐1 infection in the past two decades. However, it has been shown that HIV‐PIs induce endoplasmic reticulum (ER) stress response and subsequent activation of unfolded protein response leading to dys‐regulation of hepatic lipid metabolism and hepatotoxicity. Our recent work shows that PDE4/cAMP metabolism plays a significant role in alcohol‐induced hepatic steatosis and injury. Hence in the present study, we examined the mechanisms underlying HIV‐PI induced hepatic ER stress and toxicity with a particular emphasis on PDE4 family of enzymes.

The effects of clinically used HIV‐PIs (Ritonavir and Lopinavir) were examined both in a rat hepatoma cell line as well as rat primary hepatocytes. These studies demonstrated that PIs led to a significant loss of hepatocyte survival. Notably, inhibition of PDE4 by a specific PDE4‐inhibitor, rolipram, markedly attenuated hepatotoxicity induced by PIs. Mechanistic role of PDE4 showed that PDE4 inhibition significantly decreases the expression of the ER stress related proteins CHOP, ATF‐4 and ‐3 induced by PIs. Furthermore, examination of the PDE4/cAMP‐regulated downstream signaling demonstrated the involvement of Exchange proteins activated by cAMP (EPAC). Specifically, EPAC cAMP analogue downregulated the expression of the PI‐induced ER‐stress genes. These data identify a pathogenic/mechanistic role for PDE4 regulated cAMP‐EPAC in the development of HIV‐PI induced ER‐stress leading to hepatic steatosis and injury.

Grant Funding Source: Supported by NIH, DOD and Veterans Administration
Reversal of flow direction enhances endothelial cell arteriogenic signaling (670.9)
Authors: Heuslein Joshua , Meisner Joshua , Price Richard
Published: June 2021

The key initiating stimulus for arteriogenesis in the presence of an arterial occlusion is altered shear stress along collateral arterial pathways that bypass the occlusion. Femoral artery occlusion in the mouse leads to increased flow across all collateral arteries with some collateral segments also experiencing a reversal of flow direction. We have recently shown that these “flow reversed” segments exhibited a 4‐fold increase in leukocyte recruitment and demonstrated enhanced arteriogenesis in the gracilis collateral network. To test if endothelial cell sensitivity to the flow‐direction change was a key element of the enhanced arteriogenesis, we applied the measured the in vivo hemodynamic changes of the gracilis collateral network to cultured human umbilical vein endothelial cells (HUVECs) and performed genome‐wide transcriptional profiling and pathways analysis. Endothelial cells demonstrated a 10‐fold greater number of genes sensitive to the additional flow‐reversal stimulus, as well as a broad amplification of the gene expression patterns of cells only exposed to an increase in shear stress magnitude. Further, the addition of flow‐reversal activated many of the signaling pathways known to be key mediators of collateral growth (e.g. p38 MAPK, VEGF, HGF, PKC, and NF‐κB) when compared to steady shear stress control. These were not activated with increased shear stress alone. Microarray results were further validated by RT‐PCR of a subset of known pro‐arteriogenic genes (KLF2, eNOS, and ICAM‐1) which demonstrated an increased expression with flow reversal. These results are consistent with an increase in shear stress alone as insufficient to fully achieve the maximal activation of the arteriogenic pathway. Incorporation of directional reversal may, therefore, provide a more physiological stimulus for interrogating the central pathways that drive arteriogenesis thus leading toward novel, more effective therapeutic options.

Grant Funding Source: Supported by NIH 5R01HL074082, NIH1R21HL098632, AHA 09PRE2060385 AHA 10GRNT3490001, NSF GRFP DGE‐131
Combined effects of hypoxia, carbon monoxide and impaired pulmonary gas exchange on O2 transport and aerobic capacity (708.5)
Authors: Crocker George , Jones James
Published: June 2021

This study determined how three factors interact to limit cardiopulmonary O2 delivery, O2 extraction and maximal aerobic capacity (VO2max): 1) breathing hypoxic gas; 2) impairing pulmonary gas exchange; and 3) reducing circulatory capacitance for O2. Five goats ran on a treadmill at VO2max following oleic‐acid induced acute lung injury (ALI) or with no lung injury (NLI). Goats breathed normoxic or hypoxic inspired gas fractions (FIO2 0.21 or 0.12) with and without small amounts of CO to maintain carboxyhemoglobin fractions (FHbCO) of 0.02 or 0.30. Hypoxia and ALI induced hypoxemia and reduced O2 delivery by different mechanisms: hypoxia reduced alveolar O2 partial pressure (PO2), whereas, ALI increased alveolar‐arterial PO2 difference. Elevated FHbCO lowered O2 delivery by reducing circulatory capacitance for O2 and reduced O2 extraction by increasing hemoglobin (Hb) affinity for O2. All combinations of hypoxia, ALI and elevated FHbCO attenuated the reduction in VO2max compared to the sum of each treatment’s individual effects on VO2max when administered separately. Hypoxia and ALI administered in combination attenuated the reduction in O2 delivery without affecting O2 extraction. Elevated FHbCO and ALI attenuated the decrease in O2 delivery because increased arterial O2 saturation partially compensated for reduced circulatory capacitance. The addition of ALI to the combination of hypoxic gas and elevated FHbCO attenuated the decrease in VO2max because the decrease in O2 delivery was attenuated and O2 extraction synergistically increased. Results from this study are applicable to individuals, e.g., soldiers, rescue workers and miners, that experience traumatic lung injury while breathing hypoxic and CO‐containing gases associated with fires.

Grant Funding Source: Supported by U.S. Army Medical Research and Materiel Command with L‐3 Communications/Jaycor.
Measuring changes in locomotor activity of freshwater prawn larvae in response to exposure to water contaminants using the ViewPoint software and video tracking system (728.25)
Authors: Crooke‐Rosado Jonathan , Rivera‐Cheverez Nilsa , Sosa‐Llorens Maria
Published: June 2021

As the population grows, so does the drive for urbanization. Urbanization and the resulting anthropogenic activities have an impact on the quality of nearby water resources. Puerto Rico’s population density is one of the highest in the world. We seek to develop a protocol to measure how Puerto Rico´s high level of urban development has impacted the behavior and nervous system function of river fauna. We have started by recording movement trajectory and velocity of freshwater prawn larvae during five consecutive periods of 10‐minutes light/dark cycles, using ViewPoint´s Zebrabox. Larvae of Macrobrachium rosenbergii, a species raised through aquaculture in Puerto Rico, were more active during dark cycles, whereas those of M. carcinus, the prawn species found most commonly in Puerto Rico´s rivers, were more active during the light cycles. Recordings were then made before and after exposure to two contaminants found in Puerto Rico´s urban rivers, chromium (Cr3+) and dibutyl phthalate (DBP), in levels allowed by the EPA for drinking water. Exposure of M. rosenbergii larvae to Cr3+ did not produce any significant changes in locomotion, whereas exposure of M. carcinus larvae to DBP did, affecting parameters such as total distance travelled at slow and fast speeds. This protocol will continue to be used to test effects of other river contaminants on locomotion at various developmental stages of prawns.

Grant Funding Source: Supported by: NSF HRD‐1137725; NIH NIGMS 5SC3GM084763
A suction blister model reliably assesses skin barrier restoration and immune response (734.1)
Authors: Smith Tracey , Montain Scott , Wilson Marques , Young Andrew
Published: June 2021

This study assessed test‐retest reliability of a skin suction blister method for evaluating immune function. Up to 8 blisters (~30 mm2) were induced via suction on participant’s left and right forearm, separated by ~1 week. Fluid was sampled from blisters and the top layer was removed to reveal up to 8 wounds. Fluid was collected from wounds 4, 7 and 24 h post‐blistering, and pro‐inflammatory cytokines were measured. Transepidermal water loss, to assess skin barrier recovery, was measured daily until values were within 90% of unbroken skin. Sleep and stress (i.e., factors affecting wound healing), in the days before blistering, were assessed via activity monitors and the Perceived Stress Scale. This method was deemed reliable if correlations between the left and right arm reached 0.8. Skin barrier restoration for participants (n=16; 12M/4F; 23±5 years [mean±SD]) was 4.96±0.70 and 4.83±0.96 days for sessions 1 and 2, respectively. Correlations for skin barrier restoration, [area‐under‐the‐curve] IL‐6, IL‐8 and TNF‐α were 0.8, 0.9, 0.7, and 0.5, respectively (P<0.001‐P<0.05). When sleep and stress were considered, correlations improved for IL8 (0.8, P=0.002) and TNF‐α (0.7, P=0.01). This suction blister method is reliable for assessing skin barrier restoration and immune response, and can be used to study the functional impact of various stressors on immune function and wound healing.

Grant Funding Source: Supported by the U.S. Army Medical Research & Materiel Command
Testing the versatility of the alternating sites of reactivity mechanism in the phosphagen kinases (768.11)
Authors: Aryal Manish , Snider Mark
Published: June 2021

Phosphagen kinases achieve “buffering” of cellular ATP levels by catalyzing the reversible transfer of a phosphoryl group from ATP to a guanidino acceptor to form a high energy compound, phosphagen. Creatine kinase (CK), a PK found mainly in vertebrates, exists as a dimer in muscles; whereas, arginine kinase (AK), found exclusively in invertebrates, exists mainly as a monomer. The physiological functions of different oligomerization states within the PK family are not fully understood. Crystal structures of dimeric CK and AK are consistent with cooperativity in ligand binding between the two subunits. Based on these results, a reciprocating mechanism of catalysis was suggested for dimeric PKs. However, the exact mechanism and the potential effects of negative cooperativity on ligand binding ability of dimeric PKs remains unexplained. In this study, we’ve shown direct functional evidence of negative cooperativity in rabbit muscle CK (rbCK) by measuring the enzymes’ affinity for MgADP using isothermal titration calorimetry. Measurements of rbCK‐ligand interactions, in presence of saturating concentrations of creatine and nitrate, to form the transition‐state analogue quaternary complex, were fitted using a two‐site binding model with Kd1 = 56 ± 32 µM and Kd2 = 2.7 ± 1.4 mM. In the absence of creatine and nitrate, MgADP binding by rbCK fits a one‐site binding model, with Kd = 720 ± 330 µM. These suggest that the presence of creatine enables the conformation necessary to permit cross‐talk between the subunits. Pre‐steady state kinetic assays and the effect of viscosity on kcat show that the rate‐limiting step of reaction catalyzed by PKs is dependent on the oligomerization state of the enzyme, consistent with the alternating site of reactivity mechanism.

Grant Funding Source: NSF Grant #0619123
Substrate recognition in lysine deacetylases (769.7)
Authors: Toro Tasha , Painter Richard , Garrett Destane , Watt Terry
Published: June 2021

Protein acetylation is a widely used cell signaling mechanism which reversibly regulates many cellular processes. Lysine deacetylases (KDACs) catalyze the hydrolysis of ε‐N‐acetyl lysine residues to generate an unmodified lysine and acetate. Perturbations in this process have been linked to diseases, including cancer and inflammation. Thousands of acetylated proteins have been identified, but little is known about how proteins are deacetylated. We aim to understand how individual KDACs recognize their preferred substrates. Assays performed using standard commercial reagents and acetylated peptides as substrates suggest that KDACs and their variants have unique specificity profiles. To better understand this in a biologically relevant context, we have engineered model proteins which more closely resemble natural KDAC substrates. Each is a fixed scaffold that contains a single acetylated lysine in a defined variable sequence and secondary structure. Binding and activity for KDAC‐substrate pairs are used to determine KDAC substrate preference and specificity. By combining these results with structural data and molecular modeling, we will gain insights into the mechanism of KDAC substrate recognition.

Grant Funding Source: Supported by Louisiana Cancer Research Consortium, NIH #8G12MD007595‐05, DoD W911NF‐13‐1‐0129
Qualitative evaluation of barriers to appropriate gestational weight gain among participants in the Special Supplemental Nutrition Program for Women, Infants and Children (WIC) (807.3)
Authors: Kim Loan , Koleilat Maria , Whaley Shannon
Published: June 2021

Although recent numbers show a slowing or a leveling off of obesity rates in US, the current high rate of obesity is still a cause for great concern. Women of reproductive age who are low‐income are particularly vulnerable for becoming obese because of excessive gestational weight gain (GWG) and failing to lose the weight after delivery. In 2009 the Institute of Medicine revised its 1990 recommendations and released new GWG recommendations. Our formative study was designed to examine challenges and barriers women experience in maintaining appropriate weight gain during pregnancy. We conducted eight focus groups with a total of 45 Latina, white and black pregnant women (ages 18‐45) in the WIC program. Focus group interviews were designed to elicit culturally relevant information about how best to adapt evidence‐based intervention approaches to assist WIC participants to gain weight within IOM weight gain guidelines. We will present salient elements for adapting the IOM guidelines to develop, pilot and evaluate a generalizable and sustainable intervention to prevent excessive GWG among WIC participants in Southern California.

Grant Funding Source: USDA
Calculation of total meal δ13C from individual food δ13C (813.2)
Authors: Casperson Shanon , Schoeller Dale , Johnson LuAnn , Whigham Leah
Published: June 2021

Variations in the isotopic signature of carbon in biological samples can be used to distinguish dietary patterns and monitor shifts in metabolism. But for these variations to have meaning, the isotopic signature of the diet must be known. We sought to determine if knowledge of the 13C isotopic abundance (δ13C) of individual foods can be used to reliably calculate the δ13C of a mixed meal. Aliquots of 60 individual foods and 21 meals comprised of those foods were freeze‐dried, ground, weighed, and analyzed using an isotope ratio mass spectrometer. The δ13C of the individual foods were then used to calculate the δ13C of meals comprised of those foods and compared to the analyzed δ13C of the corresponding meal. The calculation was weighted such that the contribution of individual foods to the isotopic signature of the meal was relative to the caloric contribution of the food item to the total caloric content of the meal. The measured δ13C (‐23.76‰) and calculated δ13C (‐23.72‰) of the meals did not differ (‐0.04‰, 95% CI = ‐0.30 to 0.22‰) with limits of agreement (+/‐ 2SD) of ‐1.20 ‐ 1.12‰, and the difference was not dependent upon the magnitude of the δ13C by Bland‐Altman regression (slope = ‐0.17, p = 0.88). In conclusion, approximation of the isotopic signature of whole meals can easily and accurately be calculated when the analysis of each meal is not feasible. These results will aid in the characterization of individual dietary intake.

Grant Funding Source: Supported by he United State Department of Agriculture, Agricultural Research Service
A novel method for detecting dietary (and other) toxicities: quantifying the adverse effects of added sugar consumption (814.8)
Authors: Ruff James , Hugentobler Sara , Suchy Amanda , Sosa Mirtha , Tanner Ruth , Morrison Linda , Gieng Sin , Shigenaga Mark , Potts Wayne
Published: June 2021

The ultimate function of an organism’s physiology is the performance of complex behaviors that facilitate reproduction. Here we use Organismal Performance Assays (OPAs) to quantify declines in Darwinian fitness of house mice due to experimental exposures. OPAs are sensitive phenotyping approaches that use semi‐natural conditions to challenge the physiology of differentially treated animals in direct competition with each other. Using OPAs we demonstrated that consumption of human‐relevant levels of added sugar (25% kcal) decreases reproduction of male mice by 25% while doubling the mortality rate of females relative to starch‐fed controls. Furthermore, we showed that many clinical measures associated with proximate effects of added sugar consumption were not predictive of organismal‐level effects. We expand upon these studies by using OPAs to test for differential health consequences of the two most common forms of added sugar. We report that females fed a diet containing an equal ratio of fructose and glucose monosaccharides (modeling high fructose corn syrup; HFCS) experienced a mortality rate 1.9 times higher and produced 26% fewer offspring than those fed sucrose (fructose‐glucose disaccharide). This experiment provides evidence that fructose and glucose monosaccharides (HFCS) are more deleterious to mammalian health than isocaloric sucrose.

Grant Funding Source: Supported by NIH and NSF
Mouse embryonic stem cell differentiation into cardiomyocytes is inhibited by ethanol but only after the embryoid body stage (844.3)
Authors: DeKrey Gregory , Worley Jones Sarah , Terry Alex , Gardiner Catherine , Vaughn Brittney
Published: June 2021

Ethanol up to 0.5% is recommended for use as a solvent in mouse embryonic stem cell (mESC) differentiation assays such as the Embryonic Stem Cell Test. However, lower concentrations have been shown by some to alter mESC differentiation. In this study, we further explored the dose‐ and time‐dependent affects of ethanol on mESC differentiation into cardiomyocytes using the hanging drop culture method and J1 mESC. Among control cultures (no ethanol), rhythmically contracting cells were observed in cultures after 11 days at a frequency of 蠅64%. With continuous ethanol exposure, a significant (p 蠄 0.05) decrease in the fraction of cultures containing contracting cells was observed by 蠅68% at ethanol concentrations of 0.3% and higher and was accompanied by a 蠅30% loss of cells. With ethanol exposure during the first two days of culture only (the embryoid body stage), no significant change in the frequency of contracting cells per culture, or number of cells, was observed after 11 days at ethanol concentrations up to 0.5%. These results suggest that ethanol concentrations below 0.5% can reduce the frequency of contracting cells, at least in part, by reducing the number of cells during differentiation, and that the most sensitive time‐frame for ethanol toxicity is after the embryoid body stage.

Grant Funding Source: Supported by NSF DUE‐0622421
Understanding variation in salt sensitivity in HumMod, a human physiological simulator (857.11)
Authors: Pruett William , Husband Leland , Hester Robert
Published: June 2021

Understanding variation between humans is a critical step in maximizing the efficiency of clinical trials. We studied the chronic blood pressure response to salt loading in a population of virtual patients created in HumMod, an integrative mathematical model of human physiology. Patients differed in the parameterization of their cardiovascular and renal systems. Baseline mean pressure was 96±6 at an intake of 180 mmol Na+/day, and after one week of 250 mmol Na+/day, mean pressure was 96±6.6. 10% of individuals experienced pressure increase of more than 8 mmHg over this period, with the greatest increase measuring 23 mmHg. Sensitivity analysis confirmed that the individual correlates of chronic resting blood pressure differed from those of salt loading hypertension. Chronic pressure was affected more by the loop of Henle and distal tubule, and the efferent arteriolar resistance. Salt‐sensitivity was located in the proximal tubule, the afferent arteriole, and ANP production. Renin production was important in both cases. Sensitivity analysis confirmed that no single factor was uniquely responsible for salt sensitivity, indicating model robustness. Rather salt sensitivity represents a confluence of small divergences whose combined effect reaches physiological significance. Used in this way, the model represents a powerful tool for analyzing pooled effects and their impact on variance in human populations.

Grant Funding Source: Supported by NSF EPS‐090378 and NIH HL‐51971
Blood lactate accumulation in forced submerged turtles that can and cannot shunt (879.11)
Authors: Rana Rahul , Williams Cassondra , Hicks James
Published: June 2021

Freshwater turtles are capable of remaining underwater for over four months. This is in part due to their ability to reduce their metabolism in order to survive long periods of anoxia. Another unique ability freshwater turtles possess is the ability to shunt blood, or cause blood to deviate from the normal cardiovascular circuit due to pulmonary and vascular resistance changes. Although the functional significance of cardiac shunting is not well understood, one hypothesis for its function is that hypoxemia, induced by cardiac shunting, causes a reduction in metabolism. To test this hypothesis, levels of blood lactate, a product of anaerobic metabolism, were measured in animals that could and could not shunt. Atropine was given to the turtles to eliminate the ability to shunt. Higher blood lactate levels in turtles that cannot shunt would support the relationship between cardiac shunting and reduced metabolism. Red‐eared sliders were anesthetized and surgically fitted with catheters inserted into a blood vessel in the neck. The turtles were forcibly submerged for one hour. Blood samples were taken through the catheter. Alternatively, blood samples were collected from the tail vein before and after the submersion. Preliminary data showed no difference in lactate levels between turtles that can shunt and those that cannot. Lactate data were also analyzed to determine the aerobic dive limit (ADL) during forced submersions. The ADL is the duration of a submergence at which a significant increase in blood lactate concentration is observed. Results suggest turtles that were capable of shunting had an ADL falling between 20‐30 minutes.

Grant Funding Source: Supported by NSF (1121324‐IOS)
Changes in tracheal system structure and function within an instar in the caterpillar, Manduca sexta (879.23)
Authors: Greenlee Kendra , Pedersen Paul , Back Barbarah
Published: June 2021

Juvenile grasshoppers and caterpillars are less tolerant of hypoxia as they grow between molts. One possible explanation is that substantial soft tissue growth occurs between molts, compressing the tracheal system when the exoskeleton can expand no further. In grasshoppers, femoral air sacs become compressed, as they age between molts. Juvenile insects periodically molt their exoskeletons to enable the expansion of larger cuticular structures within. Respiratory structures are part of the exoskeleton and must also molt to grow larger. However, the mechanism for the decrease in hypoxia tolerance in caterpillars is unknown. To test the hypothesis that the caterpillar tracheal system becomes compressed during the intermolt period (instar), we used synchrotron x‐ray imaging to record tracheal system structure and function. Caterpillars at the beginning and end of each instar were placed in 21% and 1% oxygen. Maximum and minimum diameters of two major tracheae, one in the head and one in the hind segment were measured, along with body size and mass. Body mass and length increased logarithmically from hatchling to fifth instar, while head width increased only when insects molted. Maximum tracheal diameter also increased after molting, most significantly from the fourth to the fifth instar. In support of our hypothesis, both minimum and maximum tracheal diameters varied with stage differently depending on the instar. Minimum tracheal diameter decreased depending on the instar, because only older caterpillars exhibit tracheal compression in hypoxia. In older instars, head tracheae were larger than hind tracheae. In addition, in contrast to our previous work, tracheae in both the head and hind segments scaled with mass to the 0.3 power. Together, these data demonstrate that the decreased hypoxia tolerance within an instar is due to the fixed size of major tracheae and provide a comprehensive view of how the caterpillar respiratory system changes in structure and function within an instar.

Grant Funding Source: Supported by NSF IOS 0953297
Deep‐diving sea lions exhibit extreme bradycardia in long‐duration dives (879.3)
Authors: McDonald Birgitte , Ponganis Paul
Published: June 2021

Heart rate and peripheral blood flow distribution are the primary determinants of the rate and pattern of oxygen store utilization and ultimately breath‐hold duration. We investigated dive heart rate (ƒH) in five California sea lions (Zalophus californianus) during maternal foraging trips by instrumenting them with digital electrocardiogram (ECG) loggers and time depth recorders. In all dives, dive ƒH (50 ± 9, range 28‐81 beats min‐1) decreased compared to surface rates (113 ± 5 beats min‐1), with all dives exhibiting an instantaneous ƒH below resting (<54 beats min‐1). Typical instantaneous ƒH profiles of deep dives consisted of 1) an initial rapid decline in ƒH resulting in the lowest instantaneous ƒH of the dive at the end of descent, often below 10 beats min‐1, 2) a slight increase in ƒH during the bottom portion of the dive, 3) a gradual increase in ƒH during ascent with a rapid increase prior to surfacing. Extreme bradycardia and the associated reductions in pulmonary and peripheral blood flow during late descent of deep dives should a) contribute to preservation of the lung O2 store, b) increase dependence of muscle on the myoglobin‐bound O2 store, c) conserve the blood O2 store, and d) help limit the absorption of N2 at depth. This ƒH profile during deep dives of sea lions may be characteristic of deep‐diving higher vertebrates that dive on inspiration.

Grant Funding Source: Supported by the Office of Naval Research
The conserved SKN‐1/Nrf antioxidant response has complex interactions with the heat shock response (880.4)
Authors: Tang Lanlan , Choe Keith
Published: June 2021

Numerous inducible gene pathways have been defined as coordinating defense and repair in response to one of many types of stress. A major challenge now is to begin understanding how these pathways interact to optimize homeostasis, mitigate competition for common substrates, and avoid incompatibilities. In animals ranging from nematodes to mammals, the transcription factor SKN‐1/Nrf controls the expression of over 50 detoxification and antioxidation genes in response to oxidants and electrophiles. Surprisingly, we find that while SKN‐1/Nrf activity is beneficial for survival of oxidants and reactive small molecules, it is strongly detrimental to survival of heat stress. Genome‐wide chromatin‐immunoprecipitation and microarray data from the genetic model Caenorhabditis elegans suggest that SKN‐1/Nrf negatively regulates several genes within the heat shock response, including heat‐shock transcription factor 1 (HSF‐1). We also find that high temperature has complex effects on the SKN‐1/Nrf pathway; it causes accumulation of the factor in the nucleus, but interferes with induction of many target genes. Therefore, our early work suggests that there may be multiple interactions between conserved responses to oxidants and heat that influence signaling and functional outcomes of both pathways.

Grant Funding Source: NSF grant IOS‐1120130
AltitudeOmics: pulmonary gas exchange efficiency in humans with and without a PFO following 16 days of acclimatization to 5,260 m (885.2)
Authors: Elliott Jonathan , Laurie Steven , Goodman Randall , Beasley Kara , Kern Julia , Subudhi Andrew , Roach Robert , Lovering Andrew
Published: June 2021

A PFO is a source of intracardiac shunt causing impaired pulmonary gas exchange efficiency, defined by an increased alveolar‐to‐arterial PO2 difference (AaDO2). Prior studies investigating human acclimatization to high altitude (HA) have not investigated differences between subjects with a patent foramen ovale (PFO+) and those without (PFO−), yet prevalence of PFO in the general population is ~40%. Twenty‐one (11 PFO+) healthy lowlanders were studied at rest and at 70, 100, 130, and 160W of cycle ergometer exercise at sea level (SL), in acute hypoxia at 5,260 m (ALT1), and after 16 days of acclimatization to 5,260 m (ALT16). Exercise data were compared at the highest iso‐workload, within an individual, achieved at SL, ALT1 and ALT16. During exercise at SL, PFO+ subjects demonstrated a wider AaDO2 compared to PFO− subjects, however on ALT1 the AaDO2 was not different between PFO− and PFO+ subjects. At ALT16, unlike PFO− subjects, AaDO2 in PFO+ subjects was not different from ALT1. Surprisingly, at ALT16 the PFO+ group did not demonstrate an increase in resting minute ventilation and consequently, did not increase either alveolar PO2 or arterial PO2 relative to ALT1. Taken together, our data suggest that 1) intracardiac shunt in PFO+ subjects results in significantly worse pulmonary gas exchange efficiency after acclimatization to HA and 2) these subjects demonstrate physiological changes consistent with a reduced ability to acclimatize to HA.

Grant Funding Source: Supported by: Department of Defense #W81XWH‐11‐2‐0040
Hypoxia augments intracellular hydrogen sulfide in LPS‐stimulated murine macrophages (888.3)
Authors: DeLeon Eric , Olson Kenneth
Published: June 2021

Hydrogen sulfide (H2S) is an important signaling molecule, yet it has been technically difficult to measure H2S production, metabolism or distribution at the cellular and sub‐cellular level in tissue. As H2S has been implicated in hypoxic signaling, we hypothesized that H2S produced during an induced inflammatory response would be augmented under hypoxic conditions. Intracellular H2S production was monitored via silicate nanoparticles, PEBBLEs (Photonic Explorers for Bioanalysis with Biologically Localized Embedding). PEBBLES were synthesized with a hydrophilic core that traps fluorescein mercuric acetate (FMA), an analyte‐sensitive dye that becomes irreversibly quenched when bound to sulfur moieties, and a hydrophobic shell permeable to small lipophilic molecules, such as H2S. FMA‐loaded PEBBLES are thus able to provide a historical account of intracellular H2S production. Murine bone marrow‐derived macrophages (BMDM) avidly ingest PEBBLES (BMDM+P) and remain viable as determined by confocal microscopy for an extended period (72 h). Cells incubated in normoxic conditions and treated with Lipopolysaccharide (LPS) showed a slight decrease in fluorescence intensity above the control over 48hrs, which could be blocked by the pre‐treatment with aminooxyacetic acid (AOA) and proparglycine (PPG). However, cells incubated in hypoxic conditions showed much larger decreases in fluorescence intensity, particularly when pre‐treated with LPS, and were less affected by the inhibitors. This supports the hypothesis that LPS stimulates H2S production in BMDM and that this is considerably augmented by hypoxia.

Grant Funding Source: Supported by NSF DGE‐1313583 (ERD) and NSF IOS‐1051627 (KRO)
The effects of high fat diet to alter glucose‐induced modulation of 5‐HT3 receptor responses in GI‐vagal afferents is reversible (905.3)
Authors: Troy Amanda , Browning Kirsteen
Published: June 2021

5‐hydroxytryptamine (5‐HT) released from enterochromaffin cells activates gastrointestinal (GI) vagal afferent neurons. Previous studies in this lab have shown that (i) glucose modulates this 5‐HT induced response and (ii) that relatively short periods of exposure to a high fat diet (HFD) disrupt this glucose dependent modulation. The aim of this study was to investigate the reversibility of this loss of glucose modulation.

Sprague‐Dawley rats were placed on HFD (60% kcal from fat) for 3 days. Thereafter, normal chow was restored (18% kcal from fat). Nodose ganglia were removed and 5‐HT3 receptor (5‐HT3R) distribution was assessed in acutely dissociated GI‐projecting vagal afferent neurons following exposure (30min) to different glucose concentrations (1.25‐20mM).

The ability of glucose to traffic 5‐HT3Rs was restored after 2 weeks recovery on control diet although earlier timepoints showed no recovery. Specifically, after 2 weeks recovery on control diet, the relationship between extracellular glucose concentration and membrane‐associated 5‐HT3R density was linear, ranging from 27.8% in 1.25mM to 33.9% in 20mM (n=19‐22; p<0.05 vs earlier timepoints; P>0.05 vs no HFD exposure). These results suggest that while the effects of HFD exposure are reversible, the time course of recovery is much longer than the initial exposure period.

Grant Funding Source: NIH DK078364, NSF IOS1148978
Modeling the epigenetic influence of climate on upper respiratory tract proportions with two groups of Macaca mulatta (918.12)
Authors: Pagano Anthony , Laitman Jeffrey
Published: June 2021

Many studies have focused on population differences in upper respiratory tract (URT) morphology and evolutionary adaptation to climate. However, epigenetic influence of local climate on cranial development has not received much attention. This study used two samples of adult male Macaca mulatta raised in outdoor colonies in California (n=7; CA, a warmer climate) and Oregon (n=8; OR, a colder climate). Postmortem whole heads underwent CT and three‐dimensional landmark coordinate data were collected from axial slices for Generalized Procrustes Analysis. This showed a measurement artifact constrained to Principal Component 1 (PC1; roughly 60% of shape variance) with much overlap between CA and OR groups in PC2 (10.4%). However, they tended to separate on PC 3 (7.38%), on which OR specimens exhibited longer nasal roofs, taller and narrower choanae, narrower piriform apertures, increased length and angulation of the cartilaginous Eustachian tube, shorter basicrania, and less external basicranial flexion and facial kyphosis. Centroid size was larger (p<0.0009) among the OR sample but body weight was higher among the CA group (p<0.024), suggesting a larger URT relative to body size in the colder habitat. Results indicate that local climate may exert subtle epigenetic influence on URT morphology, warranting further study.

Grant Funding Source: National Science Foundation
A novel light, oxygen, or voltage fluorescent tag for structural and biophysical analysis of DNA repair enzymes (989.1)
Authors: Robertson Molly , Hatherill Robert , Fuss Jill , Tainer John
Published: June 2021

DNA is constantly threatened by internal and external pressures. Xeroderma Pigmentosum (XP) complementation groups D (XPD) and B (XPB) are helicases that unwind helix‐distorting lesions in damaged DNA allowing for repair to occur. These proteins are critical components of the Transcription Factor II H complex, and are essential for nucleotide excision repair. Three rare genetic diseases characterized by cancer and premature aging are caused by mutations in the genes that code for these helicase enzymes. In order to understand how proteins function at the molecular level, it is necessary to investigate the 3‐dimensional structure. To accomplish this, we amplified, cloned, and expressed human XPD and XPB, as well as archeal XPD from Sulfolobus acidocaldarius (SaXPD), and an associated DNA repair protein. Since crystallographic structures will be formed in an anaerobic environment, we employed the flavoprotein improved light, oxygen, or voltage sensing (iLOV) fluorescent tag to investigate target molecules in E. coli. We purified single‐domain llama nanobodies using affinity chromatography. The anti‐iLOV variants were used to optimize large‐scale purification of the DNA repair proteins of interest. We conclude that the novel DNA iLOV fusions will facilitate anaerobic crystallography techniques.

Grant Funding Source: NSF ATE DUE 1205059
Household food insecurity is associated with depression among young Cambodian women in Massachusetts (LB476)
Authors: Chen Shanshan , Peterman Jerusha , Purdue‐Smithe Alexandra , Otis Nicholas , Cordeiro Lorraine
Published: June 2021

Background: The Cambodian refugee population in the United States is at increased risk for household food insecurity and adverse mental health. There is limited literature regarding the association between food insecurity and mental health in young Cambodian women.

Objectives: The objective of this study was to investigate the association between depression status and household food insecurity among young Cambodian women in Massachusetts.

Methods: A cross‐sectional survey was conducted with young women of Cambodian heritage ages 15‐30 years of age (n=127). The dependent variable, household food security score, was measured using the USDA 6‐item module. The independent variable, depression score, was ascertained using the Harvard Trauma Scale. Multivariable linear regression was used to determine the association between depression status and household food security score, controlling for age and pregnancy status.

Results: Of 127 women, 25.6% lived in low/very low food secure households. The mean depression score was 23.8. Lower depression scores were observed among pregnant women compared to non‐pregnant women (24.3 vs. 30.9, p<0.05). Women with higher depression scores were more likely to be food insecure than women with lower depression scores (β ‐0.475; 95% CI: ‐0.949, ‐0.002), after controlling for age and pregnancy status.

Conclusion: Household food security scores were positively associated with depression among Cambodian young women. This finding suggests the role of depression as a potential indicator of household food security status. Future research on these associations among refugee women living in the United States are warranted.

Grant Funding Source: USDA