bluuebunny/crossref_metadata_2025 huggingface dataset:
Cell Cycle Coordination in Caulobacter crescentus
Authors: Graf Matthew Allan Gaffney , Gober James
Published: June 2021

In the bacterial cell cycle, the events of genetic segregation must be coordinated with those of cell division. In Caulobacter crescentus, the conserved proteins ParA and ParB interact with specific DNA regions located around the origin of replication. Shortly after replication initiation, these proteins mediate shuttling of origin proximal regions to opposing ends of the dividing cell. The Caulobacter protein FtsZ, an essential tubulin homologue, dynamically appears at the midcell just prior to cell septation. Previous work has demonstrated that changes to the endogenous levels of either ParA or ParB have severe cell‐cycle defects, including mis‐localization of the FtsZ ring. Furthermore, FtsZ midcell localization coincides with ParA/ParB polar localization, though never precedes it. Using 90° angle light‐scattering to monitor FtsZ in vitro, we show that ParA is able to prevent formation of significant FtsZ polymers, suggesting that ParA has a direct inhibitory effect on FtsZ action. We hypothesize that cell septation is inhibited by the effect of ParA on FtsZ, since FtsZ cannot polymerize at the midcell until ParA is segregated to the poles. Funding is provided by the National Science Foundation.
Increased expression of heat shock proteins in skeletal muscle induces autophagy
Authors: Mestril Ruben , Ju Jeong-Sun
Published: June 2021

PURPOSE

To determine if heat shock proteins (hsp) are involved in autophagy in mouse skeletal muscle.

METHODS

To determine whether an hsp activator stimulates autophagy in skeletal muscle, CB6F1 wild‐type mice were i.p. injected with 17‐DMAG (a hsp activator, 10 mg/kg) daily for 6 days with and without colchicine (autophagy inhibitor, 0.4 mg/kg/day) administration in the last 2 days to measure in vivo autophagic flux in skeletal muscle. In order to induce autophagy, mice were also treated with rapamycin (10 mg/kg i.p.) for 2 days with and without 2 days of colchicine administration. Tibialis anterior muscles were excised and p62/SQSTM1 and LC3 II (autophagic marker proteins) were analyzed by Western blot.

RESULTS

Western blots show that p62 protein levels were significantly decreased (~50%; P<0.05) in 17‐DMAG and rapamycin treated mouse skeletal muscles. The LC3 II protein levels were increased even further when degradation was inhibited by colchicine in 17‐DMAG treated mice by ~2‐fold (P<0.01), similar results were obtained with rapamycin.

CONCLUSION

Our study suggests that the heat shock proteins enhance autophagy in mouse skeletal muscle under basal and induced conditions, the precise mechanism by which the hsps regulate autophagy still needs to be clarified.

This research was supported by an award from the USAMRMC.
Hysteresis in the heart rate‐core temperature relationship during acute heat stress in rats: implications for systemic hemodynamics
Authors: Charkoudian Nisha , Leon Lisa , Helwig Bryan
Published: June 2021

Heart rate (HR) increases during hyperthermia, even in the absence of exercise and contributes to increased cardiac output necessary for dissipation of excess heat. It is unknown whether the onset and recovery from heat stress have different cardiovascular profiles. We hypothesized that hyperthermia‐induced tachycardia would exhibit hysteresis. Core temperature (Tc), HR and MAP were measured via radiotelemetry in conscious male Fischer 344 rats (n=8; 262±8 gms) during exposure to 37°C until a Tc of 41.8°C was reached and during recovery at 20°C. Tc, HR and MAP significantly increased during heat exposure (ascending phase; P<0.01 vs. control) and HR was significantly lower for a given Tc compared to recovery (descending phase; p<0.001). For example, at Tc = 39.5°C, HR was 365±27 bpm during the ascending phase and 527±50 bpm during the descending phase (P<0.001). Hysteresis during heat stress recovery may be a compensatory, baroreflex‐mediated response to maintain MAP during thermoregulatory vasodilation and decreased peripheral vascular resistance. These findings may have implications for understanding cardiovascular stress during recovery from heat exposure. Research supported by MRMC. Author views not official US Army or DoD policy.
A new model of acute respiratory distress syndrome due to smoke inhalation and cutaneous burns in swine
Authors: Ivey Katherine Marie , Batchinsky Andriy , Langer Thomas , Belenkiy Slava , Necsiou Corina , Vecchi Vittoria , Salinas Jose , Cancio Leopoldo
Published: June 2021

Objective

To develop a clinically relevant model of severe acute respiratory distress syndrome (ARDS) in swine with the aim to test therapeutic interventions.

Methods

Under intravenous anesthesia (ketamine, midazolam), female swine (44.8 ± 1.9kg) underwent tracheostomy, line placement, exposure to 30L of smoke, and a 40% total body surface area full‐thickness flame burn. Animals were monitored for 7 days with one‐on‐one ICU care. Post burn resuscitation using lactated Ringer's was guided by a computerized algorithm. At onset of ARDS [PaO2:FiO2 ratio (PFR) < 200], the injury group (IG, n=5) received low‐tidal volume ventilation per ARDSNet guidelines. Time controls (TC, n=2) were uninjured. Data are means; statistics by T‐test or Wilcoxon 2‐sample test.

Results

Post‐injury carboxyhemoglobin level in IG was 89.8 ± 1.4% with onset of ARDS at 22 ± 1.7 hrs post‐injury. Survival time was lower in IG (65 ± 14 hrs) compared with TC (168 hrs, p<0.0001). Peak airway pressure in IG increased above 30cm H2O 6 hrs after injury (p<0.02). PFR in IG decreased below 200 at 24hr post‐injury (p<0.01) and remained lower than TC until the end of study.

Conclusions

We have created a clinically relevant porcine model of ARDS within 24 hrs of smoke and thermal injuries. Future work includes validation of various interventions for ARDS management.

Source of support: U.S. Army Institute of Surgical Research
Semi‐automated Quantitative CT‐scan Analysis For In Vivo Lung Weight Measurement
Authors: Vecchi Vittoria , Langer Thomas , Batchinsky Andriy , Ivey Katherine , Walker Kerfoot , Necsoiu Corina , Belenkiy Slava , Dimitri Rachael , Lucas Michael , Leon Alisa , Salinas José , Cancio Leopoldo
Published: June 2021

Introduction

Acute Respiratory Distress Syndrome (ARDS) is characterized by impairment of gas exchange, lung edema and diffuse density changes on computed tomography (CT). We sought to measure lung weight through a simplified, semi‐automated method of quantitative CT scan analysis (qCT) in order to quantify lung edema.

Methods

Chest CT scans were performed in 6 pigs (46±2 kg). Five pigs had ARDS due to smoke inhalation and 40% total body surface area cutaneous burn; 1 was a healthy control. CT images were reconstructed at 2 mm thickness with a step of 20 mm, yielding 15±2 images per series. Lung weight was estimated with image‐analysis software (Maluna, Goettingen, Germany) assuming 1.06 as lung‐specific weight. After necropsy, lungs were weighed on a balance to assess agreement between qCT and post‐mortem lung weight via Bland‐Altman analysis.

Results

Lung weights ranged from 237 to 1463 g (mean 1003 g) at necropsy and from 356 to 1411 g (mean 1066 g) at qCT. A high correlation (r2=0.98, p=0.0001) was observed between the two methods. Bland‐Altman analysis showed a bias of −63.5 g with limits of agreement of 60 and −186.

Conclusions

Lung weight can be accurately measured in vivo via qCT. Quantitative CT analysis may be a useful tool to evaluate and monitor the time course of lung edema in ARDS.

Source of research support: Institute of Surgical Research, Fort Sam Houston, TX
Thermodynamic Investigation of the 4x2 Bulge Region of the Leadzyme
Authors: Frost Arian Cai , Grover Neena
Published: June 2021

The leadzyme is a small, double‐stranded, artificially created ribozyme that contains an asymmetrical 4x2 bulge. The bulge region contains four unpaired bases, with at least one non‐canonical base pair forming between C6 and A25. The bulge is catalytically cleaved by divalent lead ions between nucleotides C6 and G7. Three conserved bases C6, G9, and G24 in the bulge region are implicated in divalent metal ion binding. Crystal structure suggests a single lead ion is necessary for bond cleavage, while an additional lead ion increases the reaction rate. Lead cleavage can be out competed by high concentrations of Mg2+. The leadzyme bulge is expected to be flexible and form different structures under different ionic and pH environments. The A25•C6 non‐canonical pair forms two hydrogen bonds in NMR structure and only one hydrogen bond in the crystal structure. To examine bulge stability under various conditions, thermal denaturation experiments were performed on the wild type and various modified constructs in the presence of various concentrations of Mg2+ions, 1 M KCl, and in two different pH conditions. A control helix construct was also examined. Our data shows that the second hydrogen bond between A25•C6 does not form under the conditions examined. The helix is more stable than the wild type with penalty for breaking the helical structure by adding a 4x2 bulge being ~4 kcal/mol. The G9A construct gains significant stability in pH 7.5 compared to pH 5.5, whereas the other constructs do not show a significant gain in stability. This work was supported by NSF grant MCB‐0950582 to NG.
The Importance of a Loop Structure in ATP Apparent Affinity and Allosteric Activation of Escherichia coli ADP‐Glucose Pyrophosphorylase
Authors: Hill Benjamin L. , Wong Jennifer , Frisby‐zedan Jeanne , May Brian , Ballicora Miguel A.
Published: June 2021

Previous work into the study Escherichia coli ADP‐Glc PPase has identified several regions of the N‐terminal domain that appear to play a key role in the allosteric activation of the enzyme by Fructose‐1,6‐bisphosphate (FBP). One such region involves a loop structure formed by residues Pro103‐Gln116. Alanine scanning mutagenesis was performed on residues of this loop. The results of kinetic assays monitoring the forward (ADP‐Glc synthesis) reaction show that several residues play either a direct or indirect role in ATP binding or activation of the enzyme by FBP. These are Pro103, Gln105, Gln106, Arg107, Trp113, Tyr114, and Arg115. Aside from Arg115, whose main effect appears to have more to do with ATP binding than FBP activation, the defining characteristic of the alanine mutants was the failure to be appreciably activated by Fru‐1,6‐BP. These mutants saw near wild type activity in the absence of FBP but were only activated 1.5‐ to 5‐fold by FBP compared to 30‐fold for the wild type. Using a homology model of the E. coli enzyme (based on the crystal structures of closely related ADP‐Glc PPases from Agrobacterium tumefaciens and Potato tuber), we hypothesize some structure‐function relationships. For instance, the importance Gln105 and Gln106can likely be associated with hydrogen bond interactions with another loop structure formed by Tyr75‐Gln78 which has previously been identified as being important for ATP binding. We conclude that most of the loop is important to trigger the activation by FBP and increase the apparent affinity for ATP. Supported by funds from NSF MCB‐1024945
Probing the Role of E304 in the Allosteric Site of ADPGlucose Pyrophosphorylase from Agrobacterium tumefaciens
Authors: Bor Simona , Karzai Hoomai , Chastain Kevin , Orry Andrew , Meyer Christopher R
Published: June 2021

ADPGlucose pyrophosphorylase (ADPG PPase) catalyzes the rate limiting step of the glucan biosynthesis pathway making it a target of interest for protein engineering to produce more biodegradable carbon. Agrobacterium tumefaciens (Ag. t) ADPG PPase is activated by fructose‐6‐phosphate (F6P) and pyruvate and is inhibited by phosphate and sulfate. The Ag.t ADPG PPase structure (pdb: 3BRK) and molecular modeling studies indicate that the E304 residue is an integral part of the allosteric site. To test this hypothesis, the E304A altered protein was generated by site‐directed mutagenesis and expressed and purified for kinetic characterization. The ATP S0.5 values were higher in the E304A protein than wild‐type in both the absence and presence of activators, indicating a lower apparent affinity. The altered protein also displayed a large decrease in fold activation by both the activators F6P and pyruvate. The I0.5 values for sulfate and phosphate showed a ~13‐fold and ~8‐fold increase respectively for E304A, indicating a lower apparent affinity. Complete kinetic and structural characterization of additional altered proteins will allow for a detailed comparison to the wild‐type enzyme and a clearer understanding of structure‐function relationships. Generation and characterization of the E304Q and E304D enzymes to probe the effect of size and charge at this position are in progress. Supported by NSF Award #0448676.
Structure‐Function Studies of the ADPGlucose Pyrophosphorylase from Thermodesulfovibrio yellowstonii
Authors: Susoeff Michael , Yik Eric , Kaur Sandeep , Dua Guatam , Badal Matthew , Orry Andrew , Meyer Christopher R
Published: June 2021

ADPGlucose pyrophosphorylase (ADPG PPase, glgC gene product) catalyzes the rate‐limiting step of glucan biosynthesis in plants and bacteria. Engineering of this enzyme family will allow for the increased production of renewable carbon. The Thermodesulfovibrio yellostonii (Td.y) glgC gene has been successfully cloned and the recombinant enzyme purified. This enzyme displays only ~30% identity to other characterized ADPG PPases and harbors unusual sequences in regions involved in regulation. Molecular modeling studies revealed that the Td.y enzyme was most similar to a plant enzyme, in accord with 3‐phosphoglycerate (3‐PGA) activation. Heat stability up to 75°C required the presence of ATP. Initial kinetic studies were performed at 37°C (pH 7.5) and revealed S0.5 values for ATP and Mg of 8.0 mM and 13.9 mM, respectively, and a Vmax value of 5.33 Units/mg. The metabolites PEP (2mM), glucose‐6‐phosphate ( 2 mM), and 3‐PGA (2 mM), were found to increase the apparent affinity for ATP by 4.2, 10.3, and 3.8‐fold, respectively. PEP also increased the Vmax by 2.0‐fold. Based on alignment studies and molecular modeling, the following site‐directed mutants have been generated to probe regulatory properties: E15S, F18K, F23R, S25A, and S28A. Complete characterization of the native and altered proteins is underway. Supported by NSF Award 0448676 and a CSUPERB Presidents’ Commission Scholars grant to E. Yik and C. R. Meyer.
Structural analysis of an intein from an extreme thermophile
Authors: Williams Jennie E. , Reitter Julie N. , Mills Kenneth V.
Published: June 2021

Protein splicing is a post‐translational event by which an intervening polypeptide, the intein, facilitates its own excision from the flanking polypeptides, the exteins, and the ligation of the exteins. We have studied the structure of two inteins that interrupt the DNA PolII from the extreme thermophiles Pyrococcus abyssi (Pab) and Pyrococcus horikoshii (Pho). The two inteins have 71% sequence identity. Solutions to the NMR structure of the Pab PolII intein revealed a long flexible loop in an otherwise rigid protein; the sequence corresponding to this loop is absent in the Pho intein. We have used susceptibility to digestion by the thermostable protease thermolysin to show that the Pho intein is more rigid than the Pab intein. The Pho intein also is less active at low temperature than the Pab intein. Perhaps due to this increased rigidity, we were able to identify crystallization conditions for the Pho PolII intein. Our first crystals give diffraction data to about 2.9 Å; we hope to optimize crystallization conditions and solve the structure in collaboration with colleagues at the Wadsworth Center. We also hypothesize that the flexible loop may play a role in mechanism‐linked conformational changes that might help to coordinate the steps of splicing.

This material is based upon work supported by the National Science Foundation under grant MCB‐0950245 and by the Camille and Henry Dreyfus Foundation.
Mechanisms of Cu+ transfer from soluble Cu+ chaperones to transmembrane transport ATPases
Authors: PADILLA‐BENAVIDES TERESITA N , MCCANN COURTNEY J , ARGUELLO JOSE M
Published: June 2021

Cu+‐ATPases couple ATP hydrolysis to the transmembrane efflux of cytosolic Cu+. In this process, soluble cytoplasmic Cu+‐ chaperones (CopZ) deliver Cu+ to the ATPase (CopA) transmembrane metal‐binding sites (TM‐MBS). The crystal structure of Legionella pneumophila CopA (LpCopA; Gourdon et al. Nature 475: 59 (2011)) revealed a conserved kinked transmembrane electropositive “platform” exposed to the cytosol. Bioinformatic analysis of the chaperone CopZ indicated several electronegative exposed patches. Using Archaeoglobus fulgidus CopA‐CopZ as a model, we show that Ala mutation of specific charged regions of both proteins abolished Cu+ transference and the ATPase activity dependent on Cu+·CopZ. In addition, an invariant “entrance” site constituted by three conserved residues (Met, Asp, Glu) was identified in the LpCopA structure. Point mutation of these residues prevented CopZ‐dependent Cu+ transference and the ATPase activation. Our results support a model where upon the initial electrostatic interaction between the ATPase and the chaperone, the docking places the Cu+ proximal to the conserved carboxyl and thiol groups in the “entrance” site. These induce metal release from the chaperone through ligand exchange and transfer the ion to the TM‐MBS for ATP driven transmembrane translocation. Supported by NSF grant MCB‐0743901 (JMA).
Characterization of tocopherol kinase activity in primary human coronary artery smooth muscle cells
Authors: Zingg Jean‐Marc , Meydani Mohsen , Azzi Angelo
Published: June 2021

The vitamin E derivative, alpha‐tocopheryl phosphate (αTP), is detectable in tissues in small quantity (30–300 nM) suggesting the existence of enzyme(s) with α‐tocopherol (αT) kinase activity. Here, we have characterized the production of αTP from αT and [γ‐32P]‐ATP in primary human coronary artery smooth muscle cells (HCA‐SMC) using thin layer chromatography (TLC) followed by ultra performance liquid chromatography (UPLC). In addition to αT, γT is also phosphorylated. γTP inhibits proliferation of THP‐1 cells and reduces CD36 expression more potently than αTP (10 μM). The recombinant human tocopherol associated protein (TAP1/SEC14L2) binds both αT and αTP and stimulates phosphorylation of αT possibly by facilitating its transport and presentation to the putative αT kinase in the correct spatial orientation. Recombinant hTAP1 reduces the in vitro activity of the phosphatidylinositol‐3‐kinase gamma (PI3Kγ) potentially by sequestering the substrate phosphatidylinositol (PI). Indeed, the addition αT or αTP to the reaction stimulates PI3Kγ, most likely by facilitating egress of PI from hTAP1 and its binding to the enzyme. It is suggested that the continuous mutual exchange of different ligands in the metabolic nanoreactor formed by hTAPs may be a way to make these lipophiles more accessible as substrates to enzymes and as constituents to specific membrane domains. Supported by USDA Contract #58–1950‐0–014.
Modulating lipid fate controls lipotoxicity in palmitate‐treated hepatic cells
Authors: Leamy Alexandra , Shiota Masakazu , Young Jamey
Published: June 2021

Lipotoxicity from free fatty acid overload has been implicated in a variety of diseased states including Type II Diabetes and nonalcoholic fatty liver disease (NAFLD). Our central hypothesis is that overexposure to saturated fatty acids (SFAs) leads to increased saturation of ER membrane phospholipids, which alters membrane stability, induces ER stress and ultimately leads to lipoapoptosis. Our objective is to determine how perturbations of pathways involved in lipid metabolism can modulate SFA‐induced lipotoxicity in terms of reactive oxygen species (ROS) accumulation, caspase activation, phospholipid composition, ER stress and cell death. Stimulation of β‐oxidation with the AMPK activator AICAR reduced the lipotoxic phenotype stemming from SFA overload in H4IIEC3 hepatomas, while inhibition of this pathway with the specific CPT‐1 inhibitor Etomoxir had no positive effect on the outcome of the hepatic cells. Cells co‐treated with oleate (OA), a monounsaturated fatty acid, demonstrated increased triglyceride synthesis but almost a complete reversal of all characterizations of the lipotoxic phenotype. Our data indicates that by modulating alternative pathways of lipid metabolism in hepatic cells, the lipotoxic effects of SFAs can be significantly reduced.

This work is funded by National Science Foundation Career Award 0955251.
Protein Structure in Context: The Landscape of Angiogenesis
Authors: Pellmann Elise Arielle , Goodsell David , Ramchandran Ramani , Franzen Margaret , Herman Timothy , Sem Daniel
Published: June 2021

The aim of this work was to identify gaps in undergraduate students’ biochemistry knowledge and to create novel educational tools to address these gaps. We present a case study in which new teaching methods, including 3‐D protein models, were employed in the teaching of protein structure and function in an upper‐division biochemistry course. Final class projects on proteins in the VEGF‐angiogenesis pathway revealed that a number of students had a poor understanding of how protein functions are integrated in a signaling cascade. We thus reasoned the need for a visual device to build students’ awareness of protein biochemistry principles in their physiologically relevant context—in this case, the context of signal transduction. A collaboration among students, teachers, researchers, and a molecular artist resulted in a painting of a cellular landscape depicting VEGF signaling; we believe its construction and future classroom use in parallel with the introduction of 3‐D protein models is a powerful approach to teaching biochemistry, providing direct visual connection of macromolecular structure to cellular function.

This work was supported in part by NIH research grants HL102745–01A1 and HL112639–01 and by NSF CREST grant CCLI #1022793.
Household Food Insecurity and Dietary Intake among Hispanic Women of Childbearing Age
Authors: Hilmers Angela , Chen Tzu‐An , Hilmers David C , Cullen Karen C
Published: June 2021

Objectives

This study examined the impact of household food insecurity on the dietary intake of Hispanic women of childbearing age.

Methods

Participants were 707 Hispanic non‐pregnant, non‐breastfeeding women aged 26–44 years from three cities in Texas. Chi‐square tests, logistic regression and one‐way analysis of covariance tested the associations between food security status and dietary intake after controlling for participation in federal assistance programs, household income and composition, acculturation, and body mass index (BMI).

Results

About 77 percent of food‐insecure women participated in at least one federal assistance program. Number of children in the household was the only significant predictor of food security status with each additional child increasing the odds of being food‐insecure by 25 percent. Food insecurity was significantly associated with BMI ≥30. No significant differences in dietary intake were found by food security status.

Conclusions

Among Hispanic women, food insecurity does not affect food and nutrient intakes nor household food security always translates into consumption of nutritionally adequate foods. Public health efforts should continue to address the disparate nutritional needs of this ethnic group independent of food security status.

Grant Funding Source: National Research Initiative of the USDA Cooperative State Research, Education and Extension Service, grant number #2004–35215‐14225
Very low food security among children is associated with daily energy intake and diet quality
Authors: Burke Michael P. , Jones Sonya J. , Blake Christine E. , Fram Maryah S. , Frongillo Edward A.
Published: June 2021

Very low food security among children (VLFSC) is the most severe form of food insecurity children face in the U.S. VLFSC has increased markedly in recent years, but little is known about its nutritional consequences. We examined the differences in daily energy intake and diet quality of VLFSC compared to children in low or very low food‐secure households using the USDA household food security survey module. We used data collected from single 24‐hour dietary recalls from 137 children aged 9–15 in the greater Columbia, SC area. We tested for the association of VLFSC status with daily energy intake and diet quality using linear regression and controlling for sociodemographic covariates. VLFSC consumed 322 kcal (p ≤ 0.05) less per day than other food‐insecure children. VLFSC consumed less carbohydrates (β= −59.0 grams, p ≤ 0.01), added sugar (β= −32.6 grams, p ≤ 0.01), vitamin B‐6 (β= −0.43 milligrams, p ≤ 0.01), magnesium (β= −42.56 milligrams, p ≤ 0.05), and 9 other nutrients (p<0.11). Our findings suggest that VLFSC are consuming less food, resulting in indications both of poorer (i.e., consumption of nutrients) and better (i.e., consumption of added sugar) dietary quality. Funded by USDA‐ERS‐RIDGE.
Food insecurity and food patterns in Mexican‐heritage children
Authors: Aguilera Albert , Kaiser Lucia
Published: June 2021

The purpose of this study was to examine the relationship between food insecurity and food patterns among Mexican‐heritage children, ages 2–8 yrs., in Fresno County, California. The community‐based sample was recruited from a predominantly agricultural worker population in a small Central Valley town as part of a five‐year childhood obesity prevention study (Niños Sanos, Familia Sana, Healthy Children, Healthy Family). Only baseline data from the first year are reported here. Using a 30‐item food frequency questionnaire, bilingual researchers interviewed parents (n=61) about their child's diet and feeding practices during the past month (between July to Oct. 2012). Food security data during the previous 3 months were collected using the 18‐item Food Security Survey. Over the summer months, prevalence of low food security and very low food security was 41% and 13%, respectively. Among the children, the most frequently consumed foods (% of parents reporting consumption ≥ 1 time/day) included fresh fruit (76%); low‐fat milk (70%); corn tortillas (48.6%); and instant cereal (31%). Among less nutrient dense foods, frequency of consumption (% ≥ 1 time/day) was 12.5% for soda; 20.5% for fruit drinks; 16% for cookies; and 8% for chips. Even during the summer months when many parents are employed, food insecurity is relatively high. Funded by Niños Sanos, Familia Sana USDA‐NIFA Grant # 82705.
High Protein Diet Reduces Food Intake and Adiposity and Alters GI Microbiome
Authors: Pioli Katrina , Barbieri Chiara , Cann Isaac , Mackie Roderick , Beverly Joseph
Published: June 2021

High protein diets reduce adiposity perhaps through effects on food intake and energy expenditure. Diet composition influences the gut microbiota and recent reports support this microbiome influences energy balance. We explored whether high protein diets influence the microbiome in the hindgut. Male Sprague‐Dawley rats (n=24) were fed a control diet (15% kcal as protein) ad libitum (C) or pair‐fed (PF) or a high protein diet (HP: 50% kcal as protein) for 14 d. HP rats consumed 15% less (p<0.05) but similar weight gain. EchoMRI and dissection on day 14 confirmed HP rats had a 24% decrease (p<0.05) in body fat. Rats were euthanized and digesta samples collected from the ileal‐cecum. Bacterial 16s rRNA from digesta were amplified before being pyrosequenced. The greengenes database was used to align and identify the gene sequences of the bacterial species found. There was a 6‐fold increase in Lactobacillus, a 42% decrease in Lachnospiraceae, and a 3‐fold increase in “unclassified bacteria” in HP‐fed rats. The later accounts for 23% of total microbial population. Further refinements of samples to define subspecies and the implication of the shift in microbiome when high protein diets are fed are still in progress. Supported by The Undergraduate Research and Mentoring in New Biology program, NSF award #1041233.
Effect of Chdh deletion on mouse fetal neurogenesis and apoptosis
Authors: Lao Sai , Johnson Amy R , Mehedint Mihai G , Teng Ya‐Wen , Zhang Shucha , Zeisel Steven H
Published: June 2021

Choline dehydrogenase (CHDH) catalyzes the conversion of choline to betaine. Betaine is an osmolyte and an important methyl‐group donor. Previously, increased availability of choline to fetal brain resulted in increased hippocampal neurogenesis. The proposed mechanism involved epigenetic changes in genes that regulate cell proliferation. To determine if the effects of choline on neurogenesis are mediated by conversion to betaine and then donation of a methyl‐group for the methylation of DNA, we studied brain development in the Chdh−/− mouse. These animals cannot use choline as a methyl‐donor, and were expected to have abnormal hippocampal neurogenesis in the fetal brain. Chdh+/− breeding pairs fed AIN‐76A diet with 1.1 g/kg choline chloride were time‐mated. At embryonic day 17 (E17) of pregnancy fetal brain and liver were collected, and either fixed for immunohistochemistry (IHC) or frozen for gene expression and choline metabolite measures. Proliferation of neural progenitor cells in the subventricular region of the Chdh−/−and Chdh+/+ littermate control hippocampus was assessed using IHC for the mitosis marker phosphorylated histone 3. Apoptosis in this brain region was assessed by fluorescent TUNEL staining. We assessed developmental differences in Chdh mRNA expression; in E17 fetal liver expression was 46% lower than in adult liver (p < 0.01); in E17 whole fetal brain expression was 74% lower than in adult adult brain (p < 0.01). Preliminary results show no difference in neurogenesis between the genotypes. Measurements of apoptosis and choline metabolites are pending. These findings will help elucidate if choline modulates brain development via donation of methyl‐groups.

Grant Funding Source: Agriculture and Food Research Initiative Grant no. 2010–65200‐20354 from the USDA National Institute of Food and Agriculture.
Intakes of Dietary Flavonoid Sub‐classes and Incidence of Type 2 Diabetes
Authors: Jacques Paul F , Cassidy Aedin , Rogers Gail , Meigs James B , Dwyer Johanna T
Published: June 2021

Experimental evidence suggests that several flavonoid sub‐classes are involved in glucose metabolism, but few human studies have examined this relationship. The objective of the current study was to determine if habitual intakes of specific flavonoid sub‐classes are related to incidence of type 2 diabetes (T2D). We followed 2915 members of the Framingham Offspring cohort who were free of T2D at baseline. Dietary intakes of six flavonoid sub‐classes were quantified using a semi‐quantitative food frequency questionnaire. Diabetes was defined by fasting glucose ≥7.0 mmol/L or hypoglycemic medication use during follow‐up. We observed 308 incident cases of T2D over an average follow‐up period of 11.9 years. After multivariable adjustment and accounting for flavonoid intake during follow‐up, each 2.5‐fold increase in flavonol intake was associated with a 26% lower incidence of T2D (hazards ratio (HR) = 0.74; 95% confidence interval (CI): 0.61–0.90, Ptrend = 0.003). Each 2.5‐fold increase in flavan‐3‐ol intake was associated with an 11% lower incidence of T2D (HR= 0.89; 95% CI: 0.80–1.00, Ptrend = 0.06). No other associations between flavonoid sub‐class intake and risk of T2D were observed. Our observations support previous experimental evidence of a possible beneficial relationship between flavonoid intake and risk of T2D. Supported by ILSI, NHLBI contract N01‐HC‐25195, and USDA agreement 58–1950‐7–707.
Accuracy of weight perception following KidQuest intervention in rural South Dakota elementary students
Authors: Kemmer Teresa M. , Wey Howard , McCann Anne , Jensen Becky
Published: June 2021

The objectives were to determine: 1) accuracy of rural South Dakota 5th and 6th graders’ perception of their weight status compared to BMI and 2) if the KidQuest nutrition and physical activity program improved accuracy of weight status perception. Five schools were randomly assigned and 76 children (56% male; 47% received KidQuest intervention) participated. Children in underweight and normal categories were more likely to perceive themselves as heavier and children in overweight and obese categories were more likely to perceive themselves as lighter. Ordinal logistic regression was performed with the discrepancy score at baseline as the dependent variable and gender, intervention status, and BMI category as predictors. Males were more likely to perceive themselves as lighter than females (OR = 4.4, p < 0.01, adjusted for BMI). Compared to the normal weight category, children in the overweight and obese categories were much more likely to perceive themselves as lighter (OR = 66 for overweight and OR = 2512 for obese; both p < 0.001). For the association of intervention and change in perception, intervention females (24%) were more likely to change (p = 0.04) towards accurate perception than controls (0%) with no association for males. This suggests the intervention improved the accuracy of females’ assessment while having no influence on males.

Grant Funding Source: USDA NIFA Competitive Grant 2011 67002 30202 and USDA, SD Agricultural Experiment Station Grant SD00H249–08
Perceptions of factors and messages related to childhood obesity among Mexican‐origin parents
Authors: Vera‐Becerra Luz Elvia , Aguilera Albert , Kaiser Lucia , Manzo Rosa , de la Torre Adela
Published: June 2021

The purpose of this qualitative study was to examine perceptions, barriers, and opportunities related to the prevention of childhood obesity in a Mexican‐origin population. Following a protocol described by Krueger and Casey, Spanish‐speaking graduate students conducted five focus groups in 2010–11 among Mexican‐origin parents (n=34) of children, ages two to eight years old, in Fresno County, CA. Transcripts were prepared, based on digital recording of the sessions, and analyzed using constant comparative analysis. Two researchers independently analyzed the data for emerging themes. When asked about factors contributing to the increase in childhood obesity in the US compared to rural Mexico, parents identified changes in physical activity, less time for food preparation, poor food quality in the US, fast food, parenting practices, and school food choices. When asked about the clarity and relevance of key obesity prevention messages, parents identified promotion of family meals and fruit and vegetables as being among the most important areas to emphasize in nutrition education programs targeting this population. Some found messages about small portion sizes confusing. Emerging themes from this research can be used to develop a culturally‐nuanced childhood obesity intervention for Mexican‐origin families. Funded by UC Davis Jastro Shields and Healthy Children, Healthy Family USDA‐NIFA grant (# 82705).
Obesity Prevention in Preschool‐Aged Children: The Importance of Sleep
Authors: Golem Devon , Martin‐Biggers Jennifer , Worobey John , Byrd‐Bredbenner Carol
Published: June 2021

Home‐based behaviors, including sleep, are an understudied, yet critical factor in child weight outcomes. A comprehensive literature review, based on IOM's L.E.A.D. framework (Locate, Evaluate, and Assemble Evidence to inform Decisions) was conducted to examine relationships between sleep and obesity in preschool‐aged children. Key search terms (preschool children, obesity, overweight, sleep, and naps) yielded 73 articles from CINAHL, PsychINFO, and PubMed databases. A positive dose‐response relationship was observed between total sleep hours and overweight/obesity risk in children and adults. Evidence suggests that inadequate sleep earlier in life is associated with increased weight status later. The causal link between sleep and obesity has not been elucidated; however adult sleep deprivation studies have revealed altered leptin, ghrelin, and cortisol responses as well as impaired carbohydrate metabolism. Additionally, adult eating behavior studies indicate that restricted sleep diminishes inhibitory responses to calorically dense foods and increases activation of brain regions that positively respond to unhealthy foods. In children, increased fruit/vegetable consumption was observed with adequate sleep duration. Given the relationship between sleep and obesity, childhood obesity‐prevention efforts should help parents to learn sleep enhancement strategies.

Grant Funding Source: United States Department of Agriculture, National Institute of Food and Agriculture, Grant Number 2011–68001‐30170
Fathers’ Buying Habits Related to Increased Sweetened Beverage Consumption in Preschool Children
Authors: Coleman Ailton S. , Ferris Ann M.
Published: June 2021

The Centers for Disease Control identified the reduction of sugar‐sweetened beverage (SSB) consumption as a major strategy to reduce childhood obesity in the United States. This study examined the influence of paternal involvement on pre‐school children's SSB consumption. The study involved interviews and Home Beverage Inventory with 462 caregivers (90.2% female, 9.8% male) enrolled in a nutritional education intervention. Two open‐ended survey items measured the association between child's daily SSB consumption and paternal serving and SSB purchasing behaviors. Overall, 41% of caregivers reported that fathers served beverages to their child on any given day and 31% of caregivers reported that fathers purchased beverages for family consumption. However, within married/partnered families, 74% of fathers served their children beverages and 81% of fathers purchased beverages for their household. Preschoolers with fathers that brought beverages for the household had significantly higher odds for SSB consumption (p=.04); yet, paternal serving behaviors did not affect SSB consumption (p=.06). Interventions that aim at reducing SSB consumption should target fathers’ buying habits as a potential strategy.

Grant Funding Source: USDA/NRI 2008–55215‐19071
The impact of metabolic syndrome on child weight outcomes in pediatric obesity program for Mexican Americans
Authors: Johnston Craig Allen , Moreno Jennette P , Green Lance , El‐Mubasher Abeer , McFarlin Brian K , Foreyt John P
Published: June 2021

Adults with metabolic syndrome (MetS) are three to five times more likely to develop type 2 diabetes and cardiovascular disease. Given the long term consequences of MetS, the growing number of children meeting criteria for MetS is concerning. In order to determine the impact of MetS on pediatric weight management, data were collected from overweight and obese Mexican American children (n = 150) aged 10 to 14 who were randomized to either an instructor led intervention (ILI; n=91) or self‐help condition (SH; n=59). Approximately 20% of participants met criteria for MetS. Repeated measures ANOVAs revealed that participants without MetS in the ILI significantly decreased their zBMI at 3 months compared to children with MetS (F=12.9, p <.01). For those who met criteria for MetS, there was no difference in weight change for participants enrolled in the ILI compared to the SH condition (F=0.2, ns). Binary logistic regression demonstrated that students in the ILI with MetS were 2.4 times (95% CI, 1.0 through 5.6) more likely to gain weight compared to students without MetS (p < .05). Overall, students in a weight management program with MetS were not as successful as children without MetS in terms of maintaining or decreasing their zBMI. This is concerning as these children remain at greater risk for associated conditions in adulthood. This study was funded the United States Department of Agriculture.
The relationship between infant‐feeding attitudes and practices and infant weight at 2 and 4 months of age
Authors: Bower Katherine Marie , Nicklas Jennifer C , Sberna Angela N , Waller Jennifer J , Burney Janie L , Greer Betty P , Kavanagh Katherine F
Published: June 2021

The use of controlling feeding practices, such as restriction, has been linked to childhood overweight/obesity. A secondary objective of the Baby‐Mine study was to explore the relationship between infant‐feeding practices/attitudes and infant weight status among low‐income, formula‐feeding mothers. Fifty‐four mothers of healthy, term infants < 3 months of age provided complete data for this objective. At 2 and 4 months of age infant anthropometry was collected and mothers completed a questionnaire assessing maternal feeding beliefs and behaviors. As an example of results to be discussed, the item “I am very careful not to feed my infant too much”, with responses linked to a 5‐point Likert scale, was used to measure maternal restriction. At 2 months of age, there was no significant relationship found between maternal response to this statement and infant birthweight (p=.616) or weight at 2 months (p=.821). However, at 4 months of age, maternal agreement with this statement was significantly positively associated with infant weight (p=0.041), and accounted for 27.9% of the variability in infant weight. Similar relationships were found when evaluating weight‐for‐length z scores. Infant‐feeding practices and attitudes may be dynamic in the first few months of life and relationships with infant weight should be carefully explored.

Grant Funding Source: USDA/NIFA/AFRI Award‐2010–85215‐20663
Environmentally conscious behavior at three Northeastern universities
Authors: McPartland Steven J , Nash Jessica T , Melanson Kathleen , Hall Rachael , White Adrienne A , Horacek Tanya M , Greene Geoffrey
Published: June 2021

Environmentally‐conscious eating, also known as green eating (GE), and transportation choices play a major role in the sustainability movement. The aim of this study was to compare motivational readiness to adopt GE and sustainable transportation (ST) behaviors among three universities as well as investigate the relationship between GE and ST. Stage of Change (SOC) for GE and ST, demographics, and GE Behavior Scale score (GEB) were assessed online using previously validated surveys in convenience samples of 18–24 year old students at 3 Northeastern universities, one private and two public. The sample of 1324 students was predominantly female (70%) with mean BMI of 25.5±3.8kg/m2 and mean age of 19.4±1.4 years. A higher proportion of students were in the action/maintenance SOC for GE and ST at the private university (37% and 80%) compared to the public universities (24 and 42% for GE, 25 and 57% for ST)(p<.01) but there was no difference in GEB among universities. There were differences among universities by age, gender, and BMI. Combining universities and adjusting for demographic differences, there was an association between ST SOC and GEB (F=3.1, p<.01) with ST precontemplators demonstrating lower GEB scores than those in ST maintenance (p<.05). Findings suggest environmentally conscious behavior differs among universities and there may be a relationship between GE and ST behaviors. Research funded by the USDA.
Changes in cardiovascular risk factors after 4‐week consumption of two diet patterns: Korean and 2010 U.S. Dietary Guidelines
Authors: Schroeder Natalia , Kang Min‐Sook , Kim Yangsuk , Ha Grace , Park Young‐Hee , Kim Haeng‐Ran , Yates Allison , Caballero Benjamin
Published: June 2021

To our knowledge, no study has fed volunteers the current Dietary Guidelines for Americans diet pattern (DGA) evaluating its effect on CVD risk factors. This study assessed the effects of DGA, a Korean diet (KD) and a typical American diet (TD) on lipid profile and blood pressure (BP) in overweight, non‐Asian individuals with elevated LDL‐C. The study was a 3‐period crossover, controlled‐feeding study. Subjects were randomly allocated to 1 of 6 possible sequential orders for consuming the 3 diets for 4 weeks, separated by a 10‐day break. Subjects remained weight‐stable. Lipid profile, BP, insulin, glucose, and 24‐hr urinary sodium were determined at baseline and at the end of each diet period. Total cholesterol and LDL‐C significantly decreased on KD and DGA but not on TD. HDL‐C significantly decreased on all three diets. No diet had a significant effect on serum triglycerides, but an upward trend on KD and a downward trend on DGA resulted in a significant difference between these two diets. All three diets caused modest decreases in systolic and diastolic BP, which reached statistical significance only for DGA. No diet had significant effect on fasting insulin, whereas fasting glucose decreased significantly on KD and TD only. Urinary sodium output decreased significantly on DGA. In conclusion, after a 4‐week feeding period, KD and DGA patterns resulted in positive changes in CVD risk factors.

Supported by RDA & USDA/ARS
Do Dietary Behaviors of Adult Preterms Explain Some of the Elevated Future Risk of Cardiovascular Disease (CVD)?
Authors: Sharafi Mastaneh , Duffy Valerie B , Miller Robin J , Winchester Suzy B , Sullivan Mary C
Published: June 2021

Prematurity may increase CVD risk via altered cortisol and hypothalamic‐pituitary‐adrenal axis response. We examined if dietary behaviors could add to CVD risk in 128 adults born prematurely (67 female, P‐) and 37 full‐terms (20 female, F‐), followed since birth and tested at 23 yrs. Each completed surveys (food and non‐food preference, dietary restraint, food neophobia) and measured for adiposity, blood pressure, and serum lipids. Data were analyzed with ANCOVA (p<.05). P‐adults reported least liking for thrill‐seeking activities/foods, carrots, and protein‐rich foods, but greatest liking for high‐fat sweets or carbohydrates. P‐adults had lowest level of dietary restraint and highest food neophobia, which in turn, associated with liking a narrow range of healthy foods. Dietary behavior differences between P‐ and F‐generally were seen when excluding medical/neurological cases or small for gestational age. The birth‐term groups did not vary significantly in adiposity or serum lipids. P‐adults had higher systolic blood pressure than F‐adults, independent of adiposity.

Dietary behaviors observed in preterms may increase future CVD risk via energy‐dense food preference and low cognitive control on eating. Lower liking for new and thrill‐seeking activities and alcohol may correspond to avoidance of stressful situations.

Grant Funding Source: NIH NINR R01 003695 & USDA Hatch Project
Gender differences in hepatic lipogenic and inflammatory genes after 72 hours of high fat diet
Authors: Miller Colette , Cooney Paula T. , Rayalam Srujana , Brown Lynda M. , Baile Clifton A.
Published: June 2021

High fat diets (HFD) promote obesity and fatty liver disease in part due to upregulation of hepatic lipogenesis; females however are protected from this at long exposures to HFD. The purpose of this study was to investigate gender differences in Long‐Evans rats fed a 72 hour HFD. Body composition and qPCR was measured for hepatic lipogenic and inflammatory genes. Both genders fed HFD equally increased caloric consumption compared to low fat (LF) controls (p<0.05). HFD‐fed males had an increase in adiposity in the visceral and subcutaneous mass compared to LF controls (48.40 g vs 68.46 g; 43.60 g vs 57.86 g; p<0.05); however females were protected from such increases. Lipogenic and inflammatory gene expression was significantly downregulated after 72 hours with no gender difference observed. Females fed HFD had reduced inflammatory gene expression compared to LF‐fed females (p<0.05). HFD‐fed females also had reduced total XBP1 expression compared to both male groups (p<0.05). These results indicate that both genders respond appropriately to nutrient excess. Malfunctions in hepatic lipogenesis observed during the development of obesity occur at longer exposures to HFDs. This research was supported in part by USDA ARS NC06871, UNCG Office of Research and Economic Development, Small Business Innovation Research Grants Program (USDA) and the Georgia Research Alliance Eminent Scholar endowment.