bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and Bioavailability of Serotomide Resistant to Carboxypeptidase A.
Authors: Park Jae B
Published: June 2021

Serotomide (N‐caffeoylserotonin) is a phytochemical belonging to a group of safflomide‐type phenylpropanoid amides found in numerous plants including Coffea canephora, Theobroma cacao, and Carthamus tinctorius. A recent study suggests that serotomide is a potent serotoninergic compound able to repress forskolin‐stimulated cAMP production via binding to serotonin receptor type‐1 in the cells. The bioavailability of serotomide is currently unknown, thereby making it infeasible to evaluate its in vivo effects. For this study, serotomide was synthesized and identified using LC‐MS and MS/MS due to its commercial unavailability. To discretely and quantitatively detect serotomide and its precursors (e.g., caffeic acid and serotonin), a HPLC method was developed using a coulometric electrochemical detector. As little as 100 fmol of serotonin, caffeic acid, and serotomide was detected using the HPLC method at the respective retention times. Because serotomide contains the amide bond possibly susceptible to a main digestive protease (carboxypeptidase A), and because the susceptibility might have great impact on its absorption, the susceptibility to the protease was investigated, but found negligible. Using the HPLC method developed in this paper, the bioavailability of serotomide could be also determined in mice orally administered with two doses (2 and 4 mg/30 g body weight) of serotomide. This study indicates that serotomide is not susceptible to carboxypeptidase A, and can be absorbed as its intact form with serotonergic activity. This study was funded by USDA project 1235‐52530‐051‐00D.
English walnuts (Juglans regia L.) protect endogenous antioxidants in humans
Authors: McKay Diane L. , Chen Chung‐Yen , Yeum Kyung‐Jin , Correa Camilla R. , Blumberg Jeffrey B.
Published: June 2021

Ellagic acid monomers, polymeric tannins and related phenolic compounds isolated from English walnuts (Juglans regia L.) have been reported to inhibit LDL oxidation ex vivo and decrease biomarkers of oxidative stress in animal models. To determine whether dietary and endogenous antioxidants are preserved following walnut consumption in humans, we conducted a pilot study in 3 healthy adults. Subjects followed a low polyphenol diet for 2 d prior to the intervention. Fasting blood was then collected at baseline (0 h) and 2 h after consuming a single dose (45 g) of walnuts (WC). Lipophilic free radical initiators were added ex vivo, ±10 μM GAE methanolic walnut extract (WE). The oxidizability of lipid and aqueous plasma components were measured over 4 h and results expressed as percent area under the time course curve. WE protected α‐tocopherol against oxidation at 0 h (P=0.045), but at 2 h the in vitro effect of WE was modest due to a contributing protective action by WC (P=0.021). At 2 h WE protected β‐carotene > WC alone (P=0.039). However, the interactive effect of WC + WE was > WE alone at 0 h (P=0.026). At 2 h, WC + WE also protected lycopene > WE alone at 0 h (P=0.032). No changes in plasma antioxidant levels were observed at 2 h. These data suggest that walnuts may protect against oxidative damage in human plasma by preserving endogenous antioxidant defenses. (Supported by USDA and California Walnut Commission)
Chromium regulation of multiple gene expression in rats with high‐fructose diet‐induced metabolic syndrome
Authors: Cao Heping , Hininger‐Favier Isabelle , Benaraba Rachida , Roussel Anne‐Marie , Anderson Richard A.
Published: June 2021

Chromium (Cr) supplementation alleviates the metabolic syndrome, glucose intolerance, depression, excess body fat, and type 2 diabetes. However, not all studies have reported beneficial effects of Cr. Molecular evidence is lacking on the effects of Cr. The objective of this study was to investigate the effects of Cr on gene regulation in rats with high‐fructose diet‐induced metabolic syndrome. Wistar rats (10 per group) received a fructose‐rich diet (FD) or FD plus 2g Cr:histidine or 500 mg Cr:picolinate/kg diet for 8 weeks. Quantitative real‐time PCR was used to evaluate Cr effects on the expression of genes coding for the glucose transporter (GLUT) family, insulin‐signaling components, adipokines, pro‐inflammatory cytokines and anti‐inflammatory tristetraprolin (TTP) family in brain, kidney, liver, and muscle. Among the significant results were that many genes were down‐regulated by Cr treatments. Among those down‐regulated genes in the brain include GLUT4, INSR, IRS2, GRB2, PIK3R1, SOS1, IGF1R, IGF2R, TAU, and ZFP36L1. The expression of TTP, VEGFB, INSR and PIK3R1 was significantly reduced in the kidney. Genes with reduced mRNA levels in the liver included TTP, VEGF, GLUT2, GLUT4, INSR, PIK3CB, PIK3R1, GRB2, IGF1R, IGF2R, and HuR. No significant effects were observed in the muscle. These data demonstrate that brain, liver and kidney may be more sensitive to Cr than the muscle (Supported by USDA‐ARS).
Understanding why some elementary schools offer competitive snacks contrary to recommendations
Authors: Gonzalez Wendy , Jones Sonya J. , Frongillo Edward A.
Published: June 2021

US children have inadequate fruit and vegetable consumption. Schools have an important role to play in increasing the consumption of fruits and vegetables. We previously found that children in schools with restricted competitive snack availability were less likely to report consuming fruits and vegetables throughout the day than children in schools without such restriction, supporting recommendations that schools should restrict snack availability. Snack sales are claimed, however, to provide important revenue to schools. To test this, we examined whether school resources (i.e., federal funding, personnel, facilities) are associated with snack availability using data from 1,318 schools from the Early Childhood Longitudinal Study‐Kindergarten cohort. With logistic regression, we found that, for schools with and without the School Breakfast Program, schools with adequate facilities were, respectively, 1.8 and 3.2 more likely to have snacks available than schools with inadequate facilities. For every five years of having the same principal in the school, there was a 12% lower odds of having snacks available. These results suggest that schools with capital resources to provide adequate facilities are more likely to make competitive snacks available, and that restricting snack availability may negatively impact school resources.

Funded by: USDA/ERS
Feeding‐induced time course of changes in protein synthesis in neonatal pig skeletal muscle
Authors: Wilson Fiona A , Suryawan Agus , Orellana Renán A , Kimball Scot R , Gazzaneo Maria C , Nguyen Hanh V , Davis Teresa A
Published: June 2021

Feeding increases protein synthesis by promoting translation initiation, and in the neonate, this increase is greatest in skeletal muscle. This study aimed to identify the feeding‐induced time course of the changes in protein synthesis and translation factor activation in muscle. Piglets (n=36; 5‐7 day old) enterally fed a complete meal were killed 0 (fasting), 30, 60, 90, 120, or 240 min post‐feeding. Skeletal muscle protein synthesis reached a maximum 30 min post‐feeding, was sustained through 120 min, and returned to baseline by 120 min. The relative proportion of polysomes vs. nonpolysomes increased at 30 min only. Protein kinase B phosphorylation was maximal 30 min after feeding and fell to baseline by 90 min. Phosphorylation of mammalian target of rapamycin, eukaryotic initiation factor (eIF) 4E binding protein (4EBP1), ribosomal protein S6, and eIF4G phosphorylation increased by 30 min, remained elevated to 120 min, and returned to baseline by 240 min. The association of 4EBP1▸eIF4E was reduced and eIF4E▸eIF4G increased 30 min post‐feeding, remained so to 120 min, and then returned to baseline. Feeding rapidly increased neonatal muscle protein synthesis by enhancing translation initiation and this increase was sustained for at least 120 min after a meal, but returned to baseline by 240 min. (Supported by NIH grants AR‐44474 and DK‐15658, and USDA/ARS 6250510000‐33).
Hypoxia‐induced changes in the zebrafish skeletal muscle proteome
Authors: Chen Kan , Cole Richard B. , Rees Bernard B.
Published: June 2021

Oxygen deficiency occurs under many pathological, physiological, and environmental conditions. To identify changes in protein expression induced by hypoxic exposure, a quantitative proteomics technique (2D‐DIGE: two‐dimensional difference in‐gel electrophoresis) was used to compare skeletal muscle protein profiles of adult zebrafish exposed to 48 h of hypoxia (PO2 = 1.9 kPa) or normoxia (PO2 = 18.6 kPa). Proteins were separated over two pH ranges in the first dimension (pH 4‐7 and pH 7‐11), prior to separation in the second dimension. Over 1000 protein spots were resolved across the two pH ranges. Of these, 34 spots in the pH range of 4‐7 and 15 in the pH 7‐11 range showed statistically significant differences between the hypoxic and the normoxic groups. Twenty‐three spots in the pH 4‐7 range and 8 in the pH 7‐11 range were identified using MALDI‐TOF/TOF mass spectrometry. Spots identified as glycolytic enzymes were higher during hypoxia than in normoxia, whereas enzymes associated with mitochondrial ATP synthesis were lower during hypoxia. Interestingly, hypoxic samples exhibited higher expression of proteins identified as zebrafish hemoglobin α variants. These protein expression changes are consistent with a hypoxic response that enhances anaerobic metabolism or O2 transport to tissues. This work was funded by grants from the NSF.
Reduced heart rate variability during recovery from exertional vs. passive heat stress
Authors: Stauss Harald , Liaboe Lauren , Leon Lisa , Kregel Kevin
Published: June 2021

Acute exposure to high ambient temperatures (Ta), leading to increased core body temperature (Tc), can adversely affect physiological function. In this study we tested the hypothesis that the addition of exercise can further increase cellular stress and injury, which can subsequently translate to functional damage at a systemic level. Rats were exposed to an Ta of 39°C while resting (HS‐C) or exercising on a running wheel (HS‐EX). Once Tc reached 41.5°C the exercise protocol was stopped in HS‐EX and Ta was reduced to 25°C in both groups. Tc and blood pressure (BP) were recorded telemetrically throughout the protocol and recovery period of 24 h. Tc increased to 41.5°C within ~1.5 h in HS‐EX and within ~3 h in HS‐C. BP and heart rate (HR) increased similarly in both groups to ~180 mmHg and ~450 bpm. During recovery, Tc and BP returned to baseline levels with no significant time‐course difference. However, during the night hours of the recovery period, HR was 30‐50 bpm lower in HS‐EX than in HS‐C. In addition, LF and HF spectral powers of HR variability were reduced in HS‐EX vs. HS‐C during recovery, which may indicate greater cardiovascular impairment in HS‐EX. In conclusion, the combination of heat stress and exercise causes greater cardiovascular impairment than heat stress alone, even with the same increase in Tc and shorter overall exposure to heat stress. (Supported by USAMRMC; author views not official US Army or DoD policy)
Using genomics to contemplate microbial physiology
Authors: Scott Kathleen M
Published: June 2021

A major objective of a microbial physiology curriculum is to cement a comprehensive understanding of central carbon metabolism (glycolysis/gluconeogenesis, the pentose phosphate pathway, and the citric acid cycle). One way to meet this goal is to have students consider the catabolic and anabolic roles of these pathways in organisms with diverse physiologies (e.g., respiratory heterotrophs; nonrespiratory, fermentative heterotrophs; autotrophs). In MCB4404 Microbial Physiology Lab, we query microbial genome sequences to elucidate the presence and absence of genes encoding enzymes catalyzing steps of central carbon metabolism in a variety of microorganisms. This genome‐level approach exposes students to bioinformatics tools and allows them to test hypotheses for gene presence/absence based on their understanding of microbial physiology. This project is generously supported by the USDA Cooperative State Research and Extension Service: US Department of Agriculture Higher Education Challenge Grants Program.
Unsaturated fatty acids promote carotenoid bioavailability in vitro
Authors: Chitchumroonchokchai Chureeporn , Kamonpatana K. , Ferruzzi M. G. , Harrison E. H. , Failla M. L.
Published: June 2021

Dietary lipid is a known enhancer of carotenoid bioavailability, although the effect of type of lipid on absorption of these compounds is limited. We have investigated the effects of several common commercial lipids on bioavailability using the in vitro digestion and Caco‐2 human intestinal cells. Meals consisted of a mixed vegetable salad (3g) containing test lipid (180 mg). Micellarization and cellular uptake of β‐carotene (βC) and lycopene during small intestinal digestion was increased by lipids rich in unsaturated fatty acids: soybean oil ? olive > canola > butter. In contrast, type of lipid had minimal affect on bioaccessibility of xanthophylls. To examine the influence of lipid type on uptake and secretion of carotenoids with chylomicrons, Caco‐2 cells grown on transwell membrane were first chronically incubated with micellar mixtures of fatty acids (1.0 mM) mimicking the types and ratio of saturated to unsaturated (mono‐ + poly‐unsaturated) fatty acids (FA) present in butter (70:30), olive oil (7: 93) and soybean oil (11: 89). Then cells were exposured to micelles containing βC, LUT and a mixture of test fatty acids. Uptake and transepithelial transport of both βC and LUT were greater in cells pre‐treated with mixtures enriched in unsaturated compared to saturated FA. These results suggest that oils rich in unsaturated fatty acids promote carotenoid bioavailability. Supported by USDA NRI 2007‐02313.
Dietary lipid source alters quercetin effects on antioxidant enzyme/phase I and II gene expression in rat colon
Authors: Paulhill Kimberly J. , Taddeo Stella S. , Davidson Laurie A. , Carroll Raymond J. , Chapkin Robert S. , Lupton Joanne R. , Turner Nancy D.
Published: June 2021

We have demonstrated changes in antioxidant enzyme activities and glutathione metabolism in colonocytes from rats consuming diets containing 0.45% quercetin combined with corn oil or fish oil. The goal of this study was to query whether these changes were regulated at the transcriptional level. Therefore, real‐time PCR was used to assess the relative expression of 15 genes involved in maintaining cellular antioxidant levels and xenobiotic metabolism. Fish oil alone enhanced the level of catalase, and did not affect the expression of any other genes tested. Quercetin decreased the expression of six genes (SOD2, GPx2, GPx4, GLR2, Ephx2, Cyp1a1) and elevated the expression of Ephx1. When the interaction between quercetin and dietary lipid was analyzed, it was noted that quercetin and fish oil tended to lower the expression levels of seven genes, when compared with the fish oil rats not consuming quercetin. However, when quercetin was combined with corn oil, there was a tendency for mixed responses with four genes enhanced and two suppressed. These data suggest that the ability of quercetin to suppress expression of genes involved in regulating cellular antioxidant status and xenobiotic activation/ detoxification is amplified by its combination with fish oil. Funding USDA/CSREES 2005‐34402‐16401, 2007‐118409, and NIEHS P30‐ES09106.
Efficacy of iron supplementation for the maintenance of iron status in female Soldiers during military training
Authors: McClung James P. , Karl J. Philip , Cable Sonya J. , Williams Kelly W. , Young Andrew J. , Lieberman Harris R.
Published: June 2021

Diminished iron status has been observed following periods of increased physical activity, including military basic combat training (BCT). The objective of this study was to determine whether iron supplementation could attenuate the decrement in iron status reported in female Soldiers following BCT. In this randomized, double‐blind, placebo‐controlled trial, female Soldiers (n = 166) were provided with pills containing either ferrous sulfate (100 mg) or placebo daily through the 9‐wk BCT period. Iron status indicators were assessed in fasted volunteers prior to and immediately following BCT. In placebo‐treated volunteers there was a decrement in iron status, as red cell distribution width (RDW) and soluble transferrin receptor (sTfR) increased (p < 0.05), and serum ferritin (SF) declined (p < 0.05). Iron supplementation mitigated the effect of BCT on some indicators of iron status, as repeated measures analyses indicate a treatment effect (p < 0.05) on SF and sTfR, but not RDW. These data suggest that daily iron supplementation may partially prevent the decrement in iron status experienced by female Soldiers during BCT. However, optimal dietary strategies and supplement dosing regimens for the maintenance of iron status during military training remain to be determined. Research supported by MRMC.
ERP measures of syllable processing in 1 year olds: infant diet‐ and gender‐related differences
Authors: Pivik R. T. , Jing H. , Gilchrist J. M. , Andres A. , Badger T. M.
Published: June 2021

Language skills are generally better in females than males, but the basis for these differences has not been determined. To investigate whether variations in infant diet contribute to these differences, cortical responses to the syllable /pa/ (ERPs;124 sites) were examined in healthy 12‐month old, full‐term infants enrolled in a longitudinal study of infant diet on development (Beginnings study). Infants were breastfed exclusively through 4 months and predominantly through 12 months (BF: n = 66, 33 males) or fed commercially produced formulas [milk‐based (MF: n = 65, 37 males) or soy‐based (SF: n = 61, 31 males)] exclusively from at least age 2 through 4 months, and remained on the same formula type through 12 months. ERPs were recorded in awake infants and analyzed using ANOVAs with post‐hoc t‐tests. Amplitude data for central and temporal cortical areas are reported for responses reflecting sensory registration (P150) and later language feature processing (P370). Group by gender interactions (p < .05) in both brain regions for the P370 reflected higher amplitudes for males than females in BF and MF groups, but not in the SF group. Across groups P370 amplitude was similar for males, but greater in SF females relative to females in other groups (p < .02). Whether these diet‐ and gender‐related differences in syllable processing relate to later language development will be determined as this longitudinal study progresses. (Supported by USDA CRIS 6251‐51000‐002‐03S)
Chondrogenic cell proliferation and signaling pathways induced by bioassayable growth hormone
Authors: Gosselink Kristin L. , Ramos Yamil , Cooper Rasalin D. , Herrera Gloria V.
Published: June 2021

Bioassayable growth hormone (BGH) was previously shown to stimulate growth of the tibial epiphyseal plate in rats in vivo, but the mechanisms contributing to this response have not been elucidated. The objective of this study, therefore, was to investigate the ability of BGH to induce cartilage proliferation in vitro, and examine the cellular signaling pathways responsible for this effect. The RCJ3.1C5.18 chondrogenic cell line was cultured to 10 days post‐confluence and stimulated with BGH‐containing plasma or conditioned media samples. Proliferation was measured by immunocytochemical staining for bromodeoxyuridine incorporation and quantified by cell counting. Intracellular protein fractions from control and stimulated cultures were isolated and subjected to Western blotting for phosphotyrosine, phosphoERK‐1/2 and phosphoMEK‐1/2. RCJ3.1C5.18 cell proliferation was significantly and dose‐dependently increased by BGH. BGH also increased the overall level of protein tyrosine phosphorylation, and elevated the cellular concentration of phosphorylated ERK‐1 and ERK‐2 in a dose‐dependent fashion. In addition, BGH enhanced the Ser/Thr phosphorylation of MEK‐2. The results demonstrate that BGH directly stimulates cartilage proliferation in vitro, and may utilize multiple signaling molecules to achieve this effect.

Support: NIH/NCRR 5G12 RR008124, NIH/NIGMS 5R25GM0490, NSF DBI‐0353887
High‐Capacity Assay to Evaluate Colony‐Forming Efficiency and Multipotency of Bone Marrow Stromal Cells
Authors: Russell Katie Claire , Phinney Donald G , Lacey Michelle R , Barrilleaux Bonnie L , Meyertholen Kristin , Prockop Darwin J , O'Connor Kim C
Published: June 2021

Human bone marrow stromal cells (hMSCs) are a promising source of multipotent progenitors for a broad range of stem cell therapies for regenerative medicine. A basic prerequisite to realizing the therapeutic potential of hMSCs is the ability to identify stem‐like progenitors in a heterogeneous culture. To overcome current limitations in stem cell identification, we have developed a novel high‐capacity assay that will characterize the heterogeneity inherent to hMSCs by (1) classifying cells according to colony‐forming efficiency as a measure of proliferation capacity and trilineage potential as a measure of multipotency and (2) preserving a frozen template of these cell populations for future use. Specifically, the assay quantifies the percentage of tripotent progenitors, bipotent progenitors, lineage‐committed unipotent progenitors and mature cells in an hMSC culture. The high‐capacity format facilitates the analysis of large sample sizes required to obtain statistically significant data on hMSC populations. The assay has numerous clinical and basic research applications, for example, to monitor hMSC preparations in the clinic for consistent content of stem‐like progenitors and to evaluate the effect of culture conditions on progenitor content in the laboratory. This work was funded with grants from NSF and NIH.
Expression of system N protein mRNA, but not system A or L, is upregulated by ileal epithelia of growing beef cattle in response to increased luminal supply of energy but not amino acids
Authors: Liao Shengfa F , Xue Yan , Boling James A , Matthews James C
Published: June 2021

To complete our in vivo study of how basal expression profiles of 20 amino acid (AA) transporter genes respond to increases in luminal supply of substrates or energy in the small intestine, total RNA was extracted from duodenal (D), jejunal (J), and ileal (I) epithelia of 18 ruminally and abomasally catheterized Angus steers (BW ? 260 kg) fed an alfalfa‐cube based diet at 1.3× NEm requirement and infused for 14 to 16 d with either (n = 6) water (basal) or corn starch hydrolysate (20% ME intake) into rumen (increased microbial AA) or abomasum (increased glucose/energy). The effect of infusion treatments on expression of mRNA encoding systems A (ATA1, 2, 3), N (SN1, 2), and L (LAT1, 2) neutral AA transporters was evaluated by real‐time RT‐PCR methodoloy. Basal expression of all mRNA but ATA3 differed (P = 0.06) among D, J, and I: ATA1, D=J>I; ATA2, D=J, D=I, J>I; SN1, D>J=I; SN2, J>D=I; LAT1, D=J>I; LAT2, D=J, J=I, D 0.15) the mRNA content of these neutral AA transporters except that expression of SN1 and SN2 mRNA by I was increased (P = 0.08) 57 and 51%, respectively, with increased luminal energy supply. This latter finding suggests that luminal energy supply may limit I expression of SN1 and SN2 mRNA. This study was funded by a USDA‐ARS Special Cooperative Agreement Grant.
Cannabinoid Receptor Modulation of the Defense Response in the Dorsal Periqueductal Gray
Authors: Dean Caron , Hopp Francis
Published: June 2021

The defense response is the coordinated reaction to physical and psychological stress, and has been validated as an experimental model of panic or fear. The hypothalamus and the midbrain periaqueductal gray (PAG) are key sites on the defense pathway from which sympathoexcitation, hypertension, tachycardia, increased muscle blood flow, analgesia, twitching of the vibrissae and hyperlocomotion can be evoked. Cannabinoids have been shown to be involved in anxiety‐related responses in the PAG and the present studies examined a role for cannabinoids in the mediation of the autonomic components of the defense response in the PAG. In anesthetized rats, microinjection of d,l‐homocysteic acid into the dorsal PAG could elicit a brisk sympathoexcitation, a pressor response and twitching of the whiskers. The hypothalamic defense area (HDA) was stimulated electrically at a site from which an intense sympathoexcitation and hypertension was evoked. The cannabinoid receptor (CB1R) antagonist AM251 was microinjected at the dorsal PAG site and the HDA stimulation was repeated. The renal sympathoexcitation was attenuated at 1 and 3 mins and the pressor response to HDA stimulation was attenuated at 3,5 and 10 mins post AM251. These data suggest that CB1R activation plays a role in the autonomic and cardiovascular responses of the defense response at the level of the dPAG. Supported by AHA Greater Midwest 0750010Z and NSF IOS 0751613.
Breast cancer resistant protein (Bcrp, Abcg2) contributes to active urate secretion in mouse and bird renal proximal tubule
Authors: Bataille Amy M. , Renfro J. Larry
Published: June 2021

Unlike most mammals, higher primates, humans, and birds lack uricase and must rely primarily on urinary excretion for the elimination of urate, the intermediate product of purine metabolism. Health complications such as gout, kidney stones, cardiovascular disease, type II diabetes, and metabolic syndrome are associated with hyperuricemia. In the renal proximal tubule, urate is strongly reabsorbed, and the bulk of that excreted is due to active tubular secretion. Following the entry step at the peritubular membrane on organic anion transporters 1 and 3 (OAT1/3), urate is transported to the lumen by a process involving multi‐drug resistance protein 4 (Mrp4, ABCC4). Recently another ATP‐binding cassette family transporter, BCRP, was identified as a possible apical membrane urate efflux transporter. In this study, primary cultures of mouse (mPTCs) and chicken (cPTCs) renal proximal tubule cell monolayers were used to further examine the role of Bcrp in urate secretion. Unidirectional urate flux measurements across mPTCs and cPTCs mounted in Ussing chambers revealed net active urate secretion in both models, and in both, urate secretion was inhibited by luminal exposure to Fumitremorgin C (FTC), a known BCRP inhibitor. Peritubular exposure to FTC did not inhibit urate secretion in mPTCs or cPTCs. Supported by NSF.
Browridge morphology & hominid evolution: is there any evidence for a mechanical influence?
Authors: Dechow Paul C. , Wang Qian , Peterson Jill
Published: June 2021

If low bone strain during orofacial function in living individuals indicates that adaptations in browridge morphology during human evolution have little to do with such function, than we might expect that the loss of function has little effect on browridge structure. This study determined cortical material properties in edentulous crania and evaluated differences with dentate crania. Cortical bone from 15 edentulous skulls were measured for thickness, density, and elastic properties. Data were compared to that of dentate crania. Cortical bone from all regions of edentate facial skeletons, including the supraorbit, is thinner than in dentate skulls. Elastic and shear moduli, and density are similar or greater in the zygoma, browridges, and cranial vault, while these properties are less in the maxilla. Most cortical bone, especially in edentulous maxillae, has reduced anisotropy, and is less oriented. The loss of significant occlusal loads following edentulation may contribute to changes in material properties and orientation during bone remodeling. These results suggest that area specific cortical microstructural changes accompany bone resorption following edentulation. This effect is also found in low load areas like the browridges, suggesting that strain magnitudes alone are insufficient to suggest that function has no impact on morphology in low strain regions. Funding: NSF BCS 0725126.
Separate but equal? Relating morphological divergence to functional performance in the evolution of primate chewing
Authors: Vinyard Christopher J
Published: June 2021

A long‐standing hypothesis in studies of primate mastication argues that musculoskeletal form has changed markedly during primate evolution while masticatory behaviors, such as the jaw‐muscle activation sequence during chewing, has remained relatively similar across primates. If morphology has evolved within this conserved behavioral framework, then we predict that jaw‐muscle activity patterns exhibit limited variation across primates and show little association with jaw‐muscle and skull form among species.

To examine these relationships, we compared jaw‐muscle electromyography (EMG) data to musculoskeletal measures of the masticatory apparatus across several primates including strepsirrhines, monkeys and humans and one non‐primate treeshrew.

Contrary to the prediction of little association between jaw‐muscle activity and musculoskeletal form, we find strong associations between the timing and magnitude of jaw‐muscle EMGs and masticatory apparatus shapes. These associations fit in vivo observations and theoretical predictions linking patterns of jaw loading to morphologies providing increased load resistance. We hypothesize that several functional modules exist in the primate masticatory apparatus incorporating both neuromuscular activation and musculoskeletal form. Jaw‐muscle activity patterns appear to be an integrated and evolving part of the primate masticatory apparatus.

Supported by NSF.
B‐vitamin deficiency is protective in experimental colitis
Authors: Benight Nancy Marie , Stoll Barbara , Puiman Patrycja , Bauchart‐Thevret Caroline , Marini Juan , Burrin Douglas
Published: June 2021

Methionine (Met) cycle activity is critical for normal cell functions and requires B‐vitamin (B6/B12) as cofactors. S‐adenosylhomocysteine (SAH) is a Met cycle intermediates that is known to inhibit methyltransferases. Met metabolism is altered in patients with inflammatory bowel disease (IBD), but Met's role in IBD is poorly understood. We hypothesize that accumulation of Met metabolites due to B‐vitamin deficiency is protective in experimental colitis. Mice received either a control diet (C) or a B6/B12‐deficient diet (D) to disrupt Met metabolism for 2 weeks and were challenged for 5 days with 3% dextran sulfate sodium (DSS) to induce colitis. Clinical and histological disease indices were reduced in D compared to C, along with the colonic expression of the proinflammatory genes (TNFα and iNOS) and myeloperoxidase activity. Whole body Met flux was assessed by infusing 13C‐2H3‐Met and measuring transmethylation (TM), transsulfuration (TS) and remethylation (RM). Plasma TS was reduced but RM was increased in D mice. TM was not different between groups. Colonic SAH and plasma Met abundance also were elevated in D mice compared to C. The protective effect of B‐vitamin deficiency is associated with reduced inflammation and tissue injury. We postulate that colonic SAH accumulation reduces methyltransferase activity and leads to epigenetic suppression of proinflammatory gene expression. Funded by USDA.

Grant Funding Source: USDA
Effect of tocotrienols on immune function of young and old mice
Authors: Ren Zhihong , Pae Munkyong , Dao Maria Carlota , Smith Donald , Meydani Simin Nikbin , Wu Dayong
Published: June 2021

Alpha‐tocopherol (α‐Toc) enhances T cell function whereas little is known regarding the immunological effects of tocotrienols (T3), the other half of vitamin E family. We pair‐fed young (4‐mo) and old (23‐mo) C57BL/6 mice 0.1% Tocomin® 50%, a mixture of T3 and α‐Toc or a control diet containing equal amounts of α‐Toc for 6 wk. Lymphocyte proliferation (LP) was lower in old than in young mice. LP in old T3 group was significantly higher than in old control group, and this effect was much less significant in young mice. Splenocytes from old mice produced less IL‐2, IL‐4, and IL‐6 compared to those of young mice, but no significant age‐related difference was found in IL‐1β, TNF‐α, IFN‐γ, and IL‐10 production. T3 feeding increased IL‐1β and tended to increase IL‐2 production in old mice but not in young mice. Peritoneal macrophages from old mice produced significantly more IL‐1β, IL‐6, IL‐10, and PGE2 compared to those from young mice. T3 feeding increased IL‐1β production in both young and old mice, but had no effect on production of PGE2 or other cytokines. In vitro supplementation with purified T3 showed that T3 at all tested levels (0.01 to 5 μmol/L) enhanced LP with a potency order of α‐> γ‐> δ‐T3 and maximal enhancement was reached at 0.15, 0.3, and 0.6 μmol/L, respectively. Similar to the findings in the in vivo study, this effect was more pronounced in old than in young mice. Future studies will investigate the mechanisms for this effect of T3. Supported by USDA #58‐1950‐7‐707.
Does Inclusion of Dairy Foods in a Moderate Energy Restricted Diet Enhance Central Fat and Weight Loss in Overweight and Obese Adults?
Authors: Van Loan Marta D , Keim Nancy L. , Adams Sean H , Souza Elaine , Woodhouse Leslie , Watson Julie , Stoffel Sara , Bremer Andrew A , Witbracht Megan , Thomas Anthony P , Gertz Erik R , Chandler Carol J , Burnett Dustin , Piccolo Brian , White Emma , Holguin Evelyn , Bonnel Ellen , Campbell Caitlin , Gustafson Mary , Horn William , Schaal Karin
Published: June 2021

Research suggests high Ca or dairy intake contributes to greater weight and fat loss; this remains controversial. We examined the role of dairy food in a moderate energy restricted diet to enhance central fat and weight (WT) loss in overweight and obese adults, whose dairy consumption was ≤1 serving/d & ≤ 600 mg of dietary Ca/d. Overweight and obese (BMI = 27.4–37.5 kg/m2) men (n=20) and women (n=51) were randomly assigned to a high dairy (HD: 3–4 servings/d = 1369mg Ca/d) or low dairy (LD: ≤ 1 serving/d = 481mg Ca/d) 12 wk controlled diet. Energy balance was achieved in wks 1–3 followed by 12wk of 500 kcal/d reduction. All food was supplied by the metabolic kitchen. WT, body fat (BF) by DXA, and intra‐abdominal adipose tissue (IAAT) by CT‐scan were measured pre‐ and post‐intervention. GLM analysis adjusted for initial WT, BF and IAAT showed no significant difference in percent change of WT (p = 0.94), BF (p = 0.68) or IAAT (p = 0.41) by treatment.

Treatment
Δ Weight, kg
Δ Body Fat, kg
Δ Intra‐abdominal Adipose Tissue, cc

HD
−6.20 ± 2.9
−5.19 ± 2.7
−8.0 ± 6.9

LD
−6.04 ± 3.2
−5.36 ± 3.0
−10.26 ± 9.73

An energy restricted diet with 3–4 servings of dairy does not enhance central fat or weight loss over energy restriction alone. Funding: National Dairy Council; USDA, ARS, WHNRC; Dairy Council of California; CTSC, Clinical Research Center at the University of California (1M01RR19975‐01), and National Center for Medical Research (UL1 RR024146)
Heterochrony of cranial features associated with wide jaw gapes in common marmosets (Callithrix jacchus)
Authors: Mork Amy Lovejoy , Vinyard Christopher J
Published: June 2021

Marmosets are unique among platyrrhines for habitually gouging trees with their anterior teeth to stimulate exudate flow. We previously demonstrated that marmosets exhibit cranial features that facilitate biting at wide jaw gapes during gouging, as compared to skulls of non‐gouging tamarins. Here we examine the role of heterochronic shifts during the ontogeny of cranial features facilitating wide gapes.

Three cranial dimensions associated with wide gapes were measured, as well as three dimensions related to load resistance in ontogenetic series from neonates to adults of marmosets (Callithrix jacchus, N=129) and tamarins (Saguinus fuscicollis, N=135). All specimens were captive individuals housed at Oak Ridge Associated Universities' Colony with known ages at death.

Marmosets exhibit a complex pattern of heterochronic shifts in cranial features linked to wide gape throughout ontogeny relative to tamarins. The relatively elongated anteroposterior glenoid, condyle and mandible of marmosets consistently appear peramorphic during ontogeny. Corporal and symphyseal dimensions associated with load resistance consistently appear paedomorphic in marmosets.

Results support a hypothesis that the shape differences facilitating wide jaw gapes are the result of multiple heterochronic shifts in ontogenetic trajectories between gouging marmosets and non‐gouging tamarins.

Supported by NSF (BCS‐0412153, BCS‐0094666).

Grant Funding Source: Supported by NSF (BCS‐0412153, BCS‐0094666)
The Varied Roles of Conserved Arginine Residues near Beta‐turns in Glyoxysomal Malate Dehydrogenase
Authors: Hedrick Shannon , Bell Ellis
Published: June 2021

In previous experiments, poly‐glutamine insertion mutants, Q301 and Q240, at pre‐existing glutamines within or very near beta turns we made. The crystal structure of Q301 indicated minimal overall changes. Q240 interacted with other proteins to form aggregates. We decided to investigate the roles of beta turns. Analysis of temperature factors of gMDH indicated a flexible beta turn. Within this “hot‐spot” flexible loop, lies R130 and R124, part of the malate binding site, which also includes R196. These arginines and R185 were mutated to a variety of amino acids. Arginine to glutamate mutations showed a large reduction in activity, however NADH was bound more tightly and oxaloacetate more weakly. R130Q and R130L had activities similar to native with R130L showing enhanced activity. R130Q and R130L also had similar CD spectra. R130E, however, had a significantly altered spectrum suggesting increased beta‐strand formation. Thermal denaturation studies indicated that R130Q had similar stability to native, but R130E had significantly lower stability. R130L, however, may be more stable due to the hydrophobicity of the mutation. We conclude that various arginine residues play roles both in substrate binding and catalysis.

This work is supported by NSF Grant MCB 0448905 to EB
Thermodynamics of small symmetrical internal loops in RNA: sequence, pH and ion effects
Authors: Furniss Stephanie K. , Grover Neena
Published: June 2021

Folding of single‐stranded RNA upon itself generates complex structures containing many bulges and loops along with A‐form helical regions. Specific symmetrical bulges in RNA exist in various biological structures, including leadzyme, thiamine pyrophosphate riboswitch and certain tRNAs. Small symmetrical loops in RNA show significant thermodynamic differences that are dependent on the closing base pairs and the base sequences of the internal loops. In this study, seven 2 x 2 symmetrical bulged‐RNA constructs were examined along with various control RNA. In 1 M KCl at pH 7.5, only small differences in RNA stability were observed, with construct being the least stable and being the most stable. In 1 M KCl at pH 5.5, the differences in stability were significantly greater, with construct being the least stable and the construct being the most stable. Magnesium ions had a modest effect on RNA stability in pH 7.5 conditions, with only a small gain in RNA stability (0.5 kcal/mol) seen for some constructs. In pH 5.5 and 9.5 mM Mg2+ ions, all bulged‐RNA constructs examined gained ~1 kcal/mol relative to 1 M salt, indicating protonation‐dependent bonding in the loops. The thermodynamic effects of varying concentrations of monovalent and divalent ions on the non‐canonical base pairs in the bulge and the effect of closing canonical base pairs will be presented. This work was funded by NSF MCB‐0621509 to NG.
How Does the DRI and Other Prediction Equations for Energy Intake Compare to Energy Fed?
Authors: Souza Elaine , Keim Nancy L. , Adams Sean H , Watson Julie , Stoffel Sara , Burnett Dustin , Blankenship Jeanne , Van Loan Marta D
Published: June 2021

Assessing energy needs is critical to dietary prescriptions for weight loss. We compared estimated calories from the Dietary Reference Intakes (DRI) equation and other accepted equations [Harris‐Benedict (HB) and Mifflin‐St.Jeor (MSJ)] to calories Fed in a controlled feeding study. Caloric needs were calculated for 79 overweight and obese (BMI: 27.5 – 37.5) women (n=56) and men (n=23) in a controlled feeding study. Calories were based on the DRI equation and adjusted during the controlled feeding period to maintain body weight (WT). WT was measured daily in the fasted state with clothing and without shoes. Calories were adjusted after 5 days of a consistent upward or downward slope in WT; further adjustments were made if body weight did not stabilize. WT stabilization was achieved in 21 days. Comparison between actual Fed calories and predicted calories from DRI, HB and MSJ equations are in Table 1.

Fed
DRI
Harris‐Benedict
Mifflin‐ St. Jeor

Mean
2585.9
2580.2
2506.8
2384.0

STD
416.8
412.6
451.7
401.9

Significant correlations were observed among Fed calories and predicted calories for DRI (R2 = 0.97), HB (R2=0.85) and MSJ (R2 = 0.82). MSJ equation under estimated calories in 57% of people by −100 to −600 kcal/d. HB deviations in estimated calories ranged from +220 to −400 kcal/d in 49% of subjects. DRI estimated calories had the fewest deviations; 16.5% of subjects ranging from +200 kcal/d to −200 kcal/d.

Funding: National Dairy Council, USDA, ARS, WHNRC, Dairy Council of California, CTS, Clinical Research Center, University of California (1M01RR19975‐01), and National Center for Medical Research (UL1 RR024146)
Microfluidic chambers used to test whether episodic breathing is regulated by the pons in turtle brainstems
Authors: Bartman Michelle Ellen , Krisp Ashley Rachel , Johnson Stephen Mark
Published: June 2021

Our goal is to locate and characterize neurons controlling respiratory motor burst timing. Episodic breathing (clusters of fictive breaths separated by apneas) is expressed in isolated adult turtle brainstems and is regulated by serotonin 5‐HT3 receptor activation (decreases bursts/episode) and blockade (increases bursts/episode). To test whether pontine 5‐HT3 receptors regulate episodic breathing, microfluidic chambers constructed from silicone elastomer were used to apply drugs selectively to the pons. In time controls (n=2), baseline episodic discharge (1.9 bursts/episode) was unchanged after 2.0 h (1.8 bursts/episode). Application of a 5‐HT3 agonist to the pons (n=1) switched respiratory motor bursts from 1.5 bursts/episode (baseline) to singlet discharge (1.0 bursts/episode) within 5 min. 5‐HT3 antagonist application to the pons (n=1) increased baseline discharge from 1.0 to 1.4 bursts/episode after 40 min. These observations suggest that the pons plays an important role in regulating episodic breathing. Funded by NSF (IOB 0517302).
Dynamic interactions among proteins of the bacterial flagellar type III secretion apparatus
Authors: Scott Israel M. , Wilson Jo Leanna , McMurry Jonathan L.
Published: June 2021

While interactions among proteins of the flagellar Type III secretion (T3S) export apparatus have been reported, few have been examined with respect to the dynamic relationships that must govern the mechanism of export. Using biolayer interferometry (BLI), an optical biosensing method, we have undertaken a survey of protein‐protein interactions among the soluble apparatus proteins (FlhAc, FlhBc, FliH, FliI, FliJ, FliK) and between apparatus proteins and export substrates. Proteins were purified prior to screening for binding partners. One of each potential pair was immobilized and then exposed to others in solution. Interactions identified by yes/no screens were subjected to rigorous characterization to measure affinity and rate constants. Our screen may uncover important interactions heretofore unknown because they are of insufficient affinity for copurification or affinity blotting experiments. Characterization will also allow us to pursue efforts such as identifying export signals in substrates by searching for kinetic changes in variant constructs. We are attempting to observe more‐than‐pairwise interactions. Kinetic characterization of dynamic interactions will allow us develop a better understanding of T3S. This work was supported by grants from the Public Health Service (R15GM080701), NSF (CHE 0922699), the Research Corporation (CC6900).
Mapping SNAPc subunit domains that interact with specific nucleotide positions in the U1 and U6 snRNA gene promoters
Authors: Stumph William E , Kim Mun kyoung , Kang Yoon Soon
Published: June 2021

The small nuclear RNA activating protein complex (SNAPc) is essential for transcription of genes coding for the snRNAs (U1, U2, etc.). In D. melanogaster, the heterotrimeric DmSNAPc recognizes a 21 base‐pair DNA sequence, the PSEA, located approximately 40–60 base pairs upstream of the transcription start site. Upon binding the PSEA, DmSNAPc establishes RNA polymerase II pre‐initiation complexes on U1‐U5 promoters but RNA polymerase III pre‐initiation complexes on U6 promoters. Minor differences in nucleotide sequence of the U1 and U6 PSEAs determine RNA polymerase specificity; moreover, DmSNAPc adopts different conformations on these different PSEAs. We have proposed that such conformational differences in DmSNAPc play a key role in determining the different polymerase specificities of the U1 and U6 promoters. To better understand the structure of DmSNAPc‐PSEA complexes, we have developed a novel protocol that combines site‐specific protein‐DNA photo‐cross‐linking with chemical cleavage of the protein. This has allowed us to map regions of the three subunits that contact specific nucleotide positions within the U1 and U6 PSEAs. These data help to establish the orientation of each DmSNAPc subunit on the DNA and have revealed cases in which different domains of the subunits differentially contact the U1 versus U6 PSEAs. (Supported by NSF and in part by the California Metabolic Research Foundation.)
Iron deficiency does not cause obesity in adult rats
Authors: McClung James P , Andersen Nancy E , Wiley Bryan C , Marchitelli Louis J , Hennigar Stephen R , Young Andrew J
Published: June 2021

Diminished iron status has been observed in obese children and adults. Prior work in our laboratory demonstrated increased fat accretion in young, growing rats fed iron‐deficient diets. The objective of this longitudinal study was to determine whether feeding iron‐deficient diets would result in increased fat accretion or obesity in adult rats. Male Sprague‐Dawley rats (initial age = 12‐wks, n = 9 per group) were fed diets containing 5, 10, 20, or 40 ppm iron for a period of 32‐wks. Diet had an effect (p < 0.05) on indicators of iron status, including hemoglobin and liver iron levels. Dual X‐ray absorptiometry indicated that diet had no effect (p > 0.05) on lean body‐ or fat mass at wks 0, 16, or 32. Similarly, body weight was not affected (p > 0.05) by dietary iron. Final body weights were (mean ± SD) 575 ± 45, 533 ± 49, 549 ± 35 and 566 ± 35 gm, for rats fed diets containing 5, 10, 20, and 40 ppm iron, respectively. These data suggest that iron deficiency does not cause increased fat accretion or obesity in adult animals. As such, it is likely that factors other than dietary iron contribute to the mechanism explaining the relationship between iron deficiency and obesity observed in human populations. Research supported by MRMC.