bluuebunny/crossref_metadata_2025 huggingface dataset:
A polyphenol‐rich sorghum cereal alters colon microbiota and plasma metabolites in overweight subjects (270.7)
Authors: Seidel Derek , Martínez Inés , Taddeo Stella , Joseph Maria , Carroll Raymond , Haub Mark , Walter Jens , Turner Nancy
Published: June 2021

Diet has the potential to impact gut microbiota and metabolism, with implications for obesity and inflammation. We have shown that polyphenol‐rich sumac sorghum (contains condensed tannins) alters microbial populations and metabolites in rats. The goal of this study was to determine if similar effects occur in overweight subjects predisposed to metabolic syndrome (MS). Subjects (n=24) were randomized in a crossover design with high (100 g/d) and low (50 g/d) intakes (4 wk) of sumac sorghum cereal incorporated in their normal diets. Sumac sorghum induced compositional changes in the fecal microbiota, such as an increase (q=0.076) in anti‐inflammatory Faecalibacterium prausnitzii species. Untargeted metabolomic analysis of plasma revealed reductions in amino acid (AA) metabolites as well as increases in microbially‐derived aromatic AA and polyphenol metabolites. 3‐hydroxyhippurate, a product of chlorogenic acid metabolism shown to be reduced in individuals with impaired glucose tolerance, was increased (q=0.0145) following sumac sorghum consumption. Three gamma‐glutamyl AAs produced by gamma‐glutamyl transferase, a biomarker for MS and cardiovascular risk, were decreased (q<0.05) with the 100 g intake. These data suggest sumac sorghum beneficially modulates gut bacteria and their metabolites, which may contribute to reduced inflammation and improved glucose sensitivity.

Grant Funding Source: Supported by United Sorghum Checkoff Program R0002‐11.
The acute effects of dietary pulses on postprandial glycemia in diabetes: a meta‐analysis (272.8)
Authors: Augustin Livia , Cozma Adrian , de Souza Russell , Sievenpiper John , Blanco‐Mejia Sonia , Li Shari , Mirrahimi Arash , Chiavaroli Laura , Ha Vanessa , Jayalath Viranda , Jenkins David , Kendall Cyril
Published: June 2021

Background and Aims: Elevated postprandial glucose (PPG) levels have been associated with higher incidence of cardiovascular disease and all‐cause mortality. Dietary pulses including beans, lentils and chickpeas have resulted in low and medium PPG responses, however most studies have included few subjects and their overall PPG responses, when taken in equicarbohydrate amounts either alone or in mixed meals, have not been systematically summarized and quantitated.

Objective: to synthesize the evidence of the effect of dietary pulses on PPG responses in individuals with diabetes.

Methods: MEDLINE, EMBASE, CINAHL and Cochrane were searched through Oct 31, 2013 for all acute human trials in individuals with type 1 and type 2 diabetes reporting data for areas under the PPG curve or glycemic indices. Data were pooled by the generic inverse variance method using random effect models and expressed as ratio of means (RoM) with 95% confidence intervals (CI). Heterogeneity was assessed by Chi2 and quantified by I2.

Results: Thirty‐six trials (n=259) from 12 published papers met the inclusion criteria. Pulses significantly reduced the relative PPG by 49% compared to an equicarbohydrate white bread control (RoM: 0.51, CI 0.45‐0.57). Heterogeneity was moderate and statistically significant (I2=30%; p<0.0001), however this effect was consistent across all types of pulses and in mixed meals. Canned pulses showed a weaker effect.

Conclusion: Pooled analyses suggest that dietary pulses in diabetic patients result in 50% significantly lower PPG rise compared to an equicarbohydrate white bread control.

Grant Funding Source: Pulse Canada and CIHR
Empiric evidence for a genetic contribution to predisposition to surgical site infection (337.2)
Authors: Hopf Harriet , Lee James , Cannon‐Albright Lisa
Published: June 2021

The genetics of microbial pathogens have been extensively studied, but there has been little work on human genetic susceptibility to surgical site infection (SSI). We analyzed a large genealogical population database to study the familial contribution to SSI. We analyzed 651 individuals with International Classification of Disease, Ninth Revision codes indicating the presence of SSI. Matched hospital controls were randomly selected from the database based on birth year, sex, and birthplace. The average relatedness of all possible pairs of cases and separately of controls (X1000 sets) was compared empirically. The relative risk (RR) for SSI was estimated by comparing the number of observed affected individuals among the relatives of cases to the number of affected individuals observed among relatives of matched hospital controls. The genealogical index of familiality test for patients with SSI showed significant excess relatedness (p < 0.010); this excess was still observed when close relationships were ignored (p = 0.019). The RR for third‐degree relatives of cases was significantly elevated (1.62, p = 0.029). The significant excess relatedness and the significantly elevated RR to distant relatives support a genetic predisposition to acquiring SSI.
Beyond facts: the deeper responsibility of teachers to their students (339.1)
Authors: Laitman Jeffrey
Published: June 2021

Anatomists are masters of factual information. Indeed, we take pride in setting the factual foundation upon which students can appreciate structure from the molecular to gross levels. As medical curricula change, countless hours have been spent morphing courses and material to accommodate new requirements for conveying the “core” material.

Although focused upon daily tasks, teachers, particularly anatomists given our role as gatekeepers to the story of human form, carry a responsibility even greater than transmitting our treasured facts. The power of the podium, combined with the nature of the material, places us in a position of both great responsibility and unique, formative influence. Indeed, the sense of respect we transmit ‐ or fail to transmit ‐ regarding the sacredness of the body will shape a student’s perception and actions more than our eloquence regarding the brachial plexus or epithelial cells. The very manner in which our malleable charges will view others is, in large part, formed by how we convey the imperative of respect for human structure and its diversity. Lessons from the past, such as the abrogation of such teaching during the era of Nazi Germany, played a significant role in allowing disrespect to morph into the incomprehensible atrocities that followed. We must never lose sight of the moral imperative to raise not only our students’ factual knowledge but their appreciation of human value as well.
Progenitor cell fate: fine tuning by blood vessels and oxygen (342.2)
Authors: Hankenson Kurt
Published: June 2021

Bone regeneration is a complex physiological process that progresses rapidly through distinct cellular and tissue types before ultimately restoring normal bone structure and function. Recent work has begun to demonstrate the essential mechanistic role of the vasculature ‐ and in turn tissue oxygenation ‐ in regulating multiple aspects of bone healing, including influencing progenitor cell differentiation. Dr. Hankenson is a mesenchymal progenitor cell biologist, whom also studies bone regeneration. His most recent work has shown that when expression of the matricellular protein thrombospondin‐2 (TSP2) is disrupted, enhanced vascularization of the early regenerate tissue (soft callus) during the fracture healing process results in differential mesenchymal progenitor cell fate through the regulation of tissue oxygenation. TSP2 is a potent angiogenesis inhibitor highly expressed during tissue regeneration. Under ischemic conditions, enhanced callus vascularization expedites healing. Computational models that consider alterations in TSP2 levels, vascularization, and oxygen gradients in the callus are highly predictive of observed experimental outcomes. These studies will be used as a starting point to discuss the role of tissue oxygenation in regulating mesenchymal cell fate and how these fate decisions impact bone regeneration.
Improving OB/GYN anatomy education through nesting interactive and clinically relevant anatomical sciences E‐modules in the curriculum (343.6)
Authors: Brown Kirsten , Krapf Jill , Ahle Samantha , Ferzli Myriam , Goldman Ellen , Butera Gisela , Jurjus Rosalyn
Published: June 2021

Several studies have shown deficits in anatomical knowledge when students start their clinical rotations. Previous data from our study of students entering the Obstetrics and Gynecology (OB/GYN) clerkship revealed weaknesses in knowledge of vascular anatomy, lymphatic anatomy, neuroanatomy, and embryology. The goal of this study was to design, implement, and evaluate an interactive method of teaching clinically relevant anatomy to students in the OB/GYN clerkship. This was accomplished through the use of two educational models, designed using principles of adult‐learning: 1) E‐modules were created using Camtasia, software that incorporates media and on‐screen recording. These modules highlighted clinically relevant anatomical topics (e.g., uterine anatomy/hysterectomy), and included an assessment of baseline knowledge, an interactive learning session, and post‐activity evaluations. 2) Hands‐on gross lab sessions were also developed to reflect the content of the e‐modules, and included model building and practicing clinical techniques. Our integrated teaching model builds on our unpublished study data, which indicated a need to close the anatomical knowledge gap found in our students. Our preliminary data also predicts the success of nesting the anatomical sciences into the curriculum. We hope to show that this nesting technique improves clinically‐relevant anatomical knowledge.

Grant Funding Source: GW Office of the Vice Provost for Teaching and Learning
Imaging RNA and RNA biology using RNA mimics of green fluorescent protein (347.1)
Authors: Jaffrey Samie
Published: June 2021

Green fluorescent protein (GFP) and its derivatives have transformed the use and analysis of proteins for diverse applications. Like proteins, RNA has complex roles in cellular function and is increasingly used for various in vitro and in vivo applications, but a comparably robust and simple approach for fluorescently tagging RNA is lacking. We will describe the generation of RNA aptamers that bind fluorophores resembling the fluorophore in GFP. These RNAs activate the fluorescence of these fluorophores, resulting in a palette of RNA‐fluorophore complexes that span the visible spectrum. An RNA‐fluorophore complex resembling enhanced GFP (EGFP), termed Spinach, emits a green fluorescence comparable in brightness to fluorescent proteins. Spinach is markedly resistant to photobleaching, and Spinach fusion RNAs can be used to image RNA localization and other RNA regulatory processes in cells. We will also discuss the use of Spinach to image other biological molecules in cells. These RNA mimics of GFP provide novel approaches to image RNA biology and other processes in cells.
Curriculum alignment: gateway to capstone (348.3)
Authors: Sears Duane , Bailey Cheryl
Published: June 2021

One goal of student‐centered education is to help students develop the facility to explore new areas of knowledge with greater confidence and independence. One “best practice” that can help students achieve this goal is to challenge them with case‐based reasoning (CBR) exercises that test their abilities to solve new problems by applying what they already know in a given discipline. To this end, a capstone immunology course is described in which small groups of students collectively work through online CBR exercises that are aimed at diagnosing the medical conditions of 25 virtual “patients” with various immune disorders. Beginning with case histories that barely hint at the underlying disorders, students attempt to identify the “best diagnosis” for each case based on evidence gathered from a menu of 100‐plus diagnostic test results (mostly presented in data format). A game‐like scoring rubric motivates careful deliberation because a student’s score is ultimately determined by the diagnosis selected from an extensive list of options and also by the overall relevance and extent of the diagnostic tests that were examined for that case. Course surveys indicate that students uniformly find that these exercises strengthen their understanding of the core concepts of immunology as well as many related concepts in biochemistry, genetics, cell biology, and microbiology.
Structural mechanisms of DNA replication restart (352.2)
Authors: Keck James
Published: June 2021

Frequent collisions between cellular DNA replication complexes (replisomes) and obstacles such as damaged DNA or frozen protein complexes make DNA replication fork progression surprisingly sporadic. These collisions can lead to the ejection of replisomes prior to the completion of replication, which, if left unrepaired, results in bacterial cell death. As such, bacteria have evolved “DNA replication restart” mechanisms that reload replisomes onto abandoned DNA replication forks and D‐loop structures that result from recombinational DNA repair. In an early step in this process, the PriA DNA helicase binds to the fork/D‐loop structure in a structure‐specific (sequence‐independent) manner ‐ this DNA‐bound form of PriA then mediates assembly of the replication restart primosome, which reloads the replicative helicase (DnaB in E. coli). We have recently determined the X‐ray crystal structure of a bacterial PriA, which reveals a core helicase domain surrounded by auxiliary DNA‐binding domains that appear to be poised for specific binding of branched DNA structures. Mechanistic insights from this structure and others will be highlighted in my talk.
Comparison of response rates, intake estimates, and preferences between the National Cancer Institute’s Automated Self‐Administered 24‐Hour Recall and interviewer‐administered Automated Multiple Pass Method recalls (36.7)
Authors: Subar Amy , Dixit‐Joshi Sujata , Potischman Nancy , Kirkpatrick Sharon , Alexander Gwen , Coleman Laura , Kushi Lawrence , Groesbeck Michelle , Sundaram Maria , Clancy Heather , Zimmerman Thea , Douglass Deirdre , Mittl Beth , George Stephanie , Kahle Lisa , Thompson Frances
Published: June 2021

Objective: To compare response rates, intake estimates, and preferences between ASA24 and interviewer‐administered AMPM recalls.

Methods: About 1200 participants were recruited from three integrated health systems using quota sampling to ensure representation of a range of ages and race/ethnicity groups. Participants were asked to complete two 24HRs, 4‐7 weeks apart, and randomized into four study groups: 1) two ASA24s; 2) two AMPMs; 3) ASA24 first and AMPM second; and 4) AMPM first and ASA24 second.

Results: Almost all enrolled participants (95%) completed at least one recall and 80% completed two; response rates did not differ by recall mode. Estimated intakes of energy, nutrients and food groups were comparable for ASA24 and AMPM; for example, energy, 2132 vs. 2126 kcal; fat, 84.9 vs. 82.8 g; saturated fat, 27.9 vs. 26.9 g; fiber, 18.4 vs. 18.4 g; and fruits and vegetables, 3.0 vs. 3.1 cup equivalents. Of participants completing one ASA24 and one AMPM, a greater percentage overall and by sex and site preferred ASA24.

Discussion: These findings show that ASA24 performs well relative to AMPM recalls. ASA24 offers significant savings over interviewer‐administered recalls, is publicly available from NCI at no charge, and has been used in over 800 studies to collect over 113,000 recalls, indicating its feasibility for use in large‐scale research. ASA24 is currently being updated to run on mobile applications.
Selenoprotein W regulates epidermal growth factor receptor trafficking, expression, and activation (374.4)
Authors: Hawkes Wayne , Alkan Zeynep , Duong Frank , Rangan Priya
Published: June 2021

Epidermal growth factor (EGF) receptor (EGFR) is the founding member of the ErbB family of growth factor receptors that control growth, proliferation, differentiation, apoptosis, and cell migration. Selenoprotein W (SEPW1) is a highly conserved, ubiquitously expressed 9 kDa selenocysteine‐containing protein involved in cell cycle control. SEPW1 siRNA inhibited EGFR activation in RWPE‐1, MCF‐10A and MCF‐7 cells, while SEPW1 overexpression increased it. SEPW1 siRNA inhibited EGF‐induced activation of downstream pathways (MAPK, PI3K/Akt, JAK/STAT, and p53), and blocked EGF‐induced cell cycle entry. SEPW1 was associated with peripheral punctuate structures that partially co‐localized with EGFR. Ligand‐bound EGFR failed to traffic towards the nucleus in SEPW1‐depleted cells, indicating that SEPW1 has a role in EGFR trafficking. Consequently, the half‐life, expression, dimerization, and phosphorylation of EGFR were also decreased in SEPW1‐depleted cells. SEPW1 siRNA also inhibited hydrogen peroxide‐induced EGFR phosphorylation. However, SEPW1 siRNA inhibition of EGF‐stimulated EGFR phosphorylation was not decreased by N‐acetylcysteine or sodium orthovanadate, indicating SEPW1 regulation of EGFR does not involve reactive oxygen species or inhibition of protein tyrosine phosphatase. Glutathione peroxidase siRNA partially rescued EGF‐induced cell cycle entry in SEPW1‐depleted cells, showing the effect of SEPW1 depletion is not due to loss of antioxidant protection. Knowledge of the mechanisms underlying SEPW1 regulation of EGFR trafficking may be important to understanding the relationship between dietary selenium and cancer.

Grant Funding Source: Supported by USDA CRIS Project 5306‐51530‐018‐00D
Physical and socioeconomic environments are associated with concurrent malnutrition in neighborhoods, households and individuals in Sub‐Saharan Africa (378.3)
Authors: Jones Andrew , Acharya Yubraj , Grisham Nicholas , Reed Terra
Published: June 2021

This study aims to determine the extent to which physical and socioeconomic environments are associated with the “dual burden” of malnutrition and its component conditions in Sub‐Saharan Africa (SSA). We used Demographic and Health Survey (DHS) data from 29 countries in SSA from 2005‐2011 (n=155,238 households), and geocoded DHS cluster data with LandScan population density data to examine spatial determinants and clustering of concurrent forms of malnutrition at neighborhood scales. We identified the co‐occurrence of maternal overweight (MO) (body mass index 蠅 25 kg/m2) and anemia (MA) (hemoglobin < 120 g/L) among non‐pregnant mothers, and, in the same households, co‐existing MO and child stunting (CS) (height‐for‐age Z‐score < ‐2) in the oldest child aged 6‐59 months. The prevalence of CS was 37%, MO and MA were 20% and 40%, respectively, 5.8% of households had concurrent MO and CS, and concurrent MO and MA was 7.7%. Rural location was negatively associated with dual burden households (OR: 0.79; 95% CI: 0.64‐0.97) and with concurrent MO and MA (OR: 0.68; 95% CI: 0.61‐0.75). Maternal employment in agriculture was independently negatively associated with both MA and MO (OR: 0.93; 95% CI: 0.87‐0.99; OR: 0.73; 95% CI: 0.69‐0.78, respectively). Household wealth was positively associated with both dual burden manifestations while years of maternal education were negatively associated with the household dual burden (OR: 0.97; 95% CI: 0.95‐0.99). We further examined heterogeneity in spatial clustering of MO, MA and CS across urbanicity gradients. Undernutrition and overweight coexist throughout SSA at regional, household and individuals scales.
Gamma tocotrienol improves high fat diet‐induced obesity and insulin resistance by inhibiting adipose inflammation and macrophage recruitment (383.4)
Authors: Zhao Lu , Kang Inhae , Okla Meshail , Ha Jung‐Heun , Lee Meeae , Marshall Maurice , Chung Soonkyu
Published: June 2021

Childhood obesity is associated with an abnormal increase of adipocyte hyperplasia. We have previously reported that gamma tocotrienol (γT3) potently inhibits adipocyte hyperplasia in human adipose‐derived stem cells. To investigate γT3 on childhood obesity, young C57BL/6J mice were fed a high fat (HF) diet containing 0.05% γT3 for 4 wks. γT3 accumulated in adipose tissue and reduced weight gain specifically in epididymal fat. γT3‐fed mice were associated with 1) decreased plasma levels of fasting glucose, insulin, and proinflammatory cytokines, 2) improved glucose tolerance, and 3) enhanced insulin signaling in adipose tissue. There was a substantial decrease of F4/80, a macrophage surface marker, and MCP1 expression suggesting that γT3 reduces recruitment of adipose tissue macrophage (ATM). Additionally, we hypothesized that γT3 sensitizes insulin by decreasing inflammation. γT3 treatment in adipocytes resulted in 1) a significant suppression of MAP kinase and NFκB activation, and 2) restoration of insulin‐stimulated glucose uptake against inflammation. In parallel, γT3 reduced LPS‐mediated M1 macrophage polarization in bone marrow stem cells. Taken together, our results demonstrated that γT3 ameliorates HF diet‐mediated visceral obesity and insulin resistance by inhibiting systemic and adipose inflammation, and ATM recruitment.

Grant Funding Source: Supported by American Heart Association
Genetic variants of rs324420 in fatty acid amide hydrolase gene influence N‐acylethanolamine concentrations in plasma during canola oil multicenter intervention trial (383.7)
Authors: Pu Shuaihua , Eck Peter , Jones Peter
Published: June 2021

N‐acylethanolamines (NAE) involve in the regulation of energy balance. The genetic polymorphisms of fatty acid amide hydrolase (FAAH) gene, which encodes the NAE degrading enzyme, are associated with obesity. The objective of the current clinical study was to investigate if genetic variants of rs324420 in FAAH gene play a role in regulating circulating NAE levels after five dietary interventions. A double‐blinded randomized crossover clinical trial consisting of five 30‐d periods was conducted. Treatments included 60 g of canola oil (Canola, 59% OA, 20% LA, 10% ALA), high oleic canola oil (CanolaOleic, 72% OA, 15% LA), high oleic canola/DHA oil (CanolaDHA, 63% OA, 13% LA, 6% DHA), corn/safflower oil (CornSaff, 18% OA, 69% LA) and flax/safflower oil (FlaxSaff, 18% OA, 38% LA, 32% ALA). OEA, AEA, PEA, LEA, ALEA, and DHEA plasma levels were measured and genotypes of rs324420 were studied. A total of 130 volunteers completed the study and 129 were successfully genotyped. 85 participants (66%) had CC, and 44 (34%) had CA or AA. Both fatty acid profiles and NAE levels in plasma reflected the dietary fatty acid composition. No differences were observed between two genotypes on OA or DHA levels. However, trends towards higher OEA (p=0.0565) and higher DHEA levels (p=0.0010) were observed in minor allele A carriers across all diets. In the comparison of two OA rich diets, CanolaDHA showed lower OEA level than CanolaOleic feeding (p=0.0006) with no difference in genotypes. CanolaDHA also showed higher DHEA level than CanolaOleic (p<0.0001) and A carriers had higher DHEA level in CanolaDHA (p<0.0001). Our data suggest that rs324420 A carriers favor higher NAE levels because of lowered FAAH activities. But dietary DHA may influence OEA levels due to a preference of such polymorphism for the hydrolysis of DHEA over OEA. The impact of genetic variants of rs324420 may be selective for specific NAEs.

Grant Funding Source: Supported by Canola Council of Canada
New USDA school meal regulations are associated with children's increased fruit and vegetable selection but not consumption (384.3)
Authors: Yon Bethany , Taylor Jennifer , Amin Sarah , Johnson Rachel
Published: June 2021

Increasing children’s consumption of fruits and vegetables (FV) is an important goal of the National School Lunch Program. As of the 2012 school year, USDA requires children to select a fruit or vegetable at lunch. The aim of this study was to compare children’s FV selection and consumption before and after the implementation of the USDA rule.

Schools (n=2) in the northeast were enrolled in 2011 (free/reduced meal eligibility 40%, 61%). Students’ (grades 3‐5) selection, consumption and waste of FV were objectively measured using validated methods (digital imaging, direct observation and weighed plate waste) prior to the new rule in spring 2012 (10 visits, tray observations n=498) and again during the 2012/13 school year (11 visits, tray observations n=944). When FV were optional, 15.9% of lunch trays did not contain FV, compared to 2.6% once required. One‐way ANOVAs were calculated on children’s FV selection, consumption and waste before and after the new USDA rules. When required to select FV, children’s lunch trays contained larger amounts (Pre: M=0.69 cups +SE 0.02, Post: M=0.89 cups +SE 0.02; p<0.0001). However, FV consumption decreased (Pre: M=0.51 cups +SE 0.02, Post: M=0.45 +SE 0.01; p=0.01) and waste increased (Pre: M=0.25 cups +SE 0.02, Post: M=0.39 cups +SE 0.01; p<0.0001). When required, more children select FV with school lunch in larger amounts; however this did not result in increased consumption.

Grant Funding Source: USDA, Vermont Agricultural Experiment Station and Bickford Scholar Research Fund
Changes in brain dynamics as a function of changes in body iron status: effects on attentional function in Indian adolescents following consumption of iron‐biofortified pearl millet (389.2)
Authors: Wenger Michael , Scott Samuel , Murray‐Kolb Laura , Cooper Elaine , Ghugre Padmini , Udipi Shobha , Haas Jere
Published: June 2021

Iron deficiency (ID) is a highly prevalent micronutrient deficiency, affecting individuals world wide. Evidence suggests that brain iron deficiency with and without anemia may disrupt myelination, neurotransmitter regulation, synaptic plasticity, neurogenesis, and brain energetics. In addition, measures of electroencephelography (EEG) have suggested systematic variations in amplitudes, latencies, and spectral power of EEG components as a function of various measures of iron status. We report analysis of data obtained in the context of a double‐blind efficacy trial, in which Indian adolescents (n = 264) were randomized to groups consuming either high‐iron biofortified or normal‐iron pearl millet. A subset of participants (n = 75, 12‐16 y, 38 females) performed three tasks (simple reaction time, go‐nogo, and the attentional network task) assessing attentional function before and after the intervention while simultaneously having EEG recorded. We observed significant decreases in the latencies and increases in the amplitudes of two early EEG components (P1/N1, P3), as well as increases in global field power and the power of γ‐band activity, all as a function of treatment group, baseline iron status, and changes in iron status. Results suggest the potential for improving brain dynamics by improving iron status and for understanding the role of iron in healthy brain function.

Grant Funding Source: HarvestPlus/IFPRI
A new human retinal pigment epithelial cell model for interrogating the protective functions of xanthophylls in retinopathies (39.2)
Authors: Gong Xiaoming , Harrell Meredith , Mitchell Dianne , Sundin Olof , Rubin Lewis
Published: June 2021

Purpose: Retinal pigment epithelium (RPE) is fundamental for vision and xanthophyll transport from the circulation to photoreceptors. RPE dysfunction occurs in numerous eye diseases, especially ischemic and neovascular retinopathies. This study is evaluates telomerase immortalized normal human RPE cells for xanthophyll vision research.

Methods: Human RPE cells (hTERT‐RPE‐1) were cultured on porous membranes for 2 days to 6 weeks. Differentiation into a polarized RPE monolayer was evaluated by confocal imaging and transepithelial resistance (TER) measurement. RPE gene expression was analyzed by microarray profiling; expression changes in specific genes were verified by qRT‐PCR and western blotting.

Results: RPE differentiation was confirmed by localization of the tight junction protein, ZO1, actin organization and development of high TER. Microarray analysis yielded 1,412 differentially expressed genes, including 852 down‐regulated genes and 560 up‐regulated genes. Gene set enrichment analysis and functional annotation clustering revealed emergence of specific gene pathways, including: retinal pigment synthesis, visual cycle, tight junctions, and transcellular transport. We also identified regulated expression of carotenoid/retinoid metabolic, transport and signaling genes, as well as of genes regulating angiogenesis, vascular remodeling, immunity and stress response. These findings indicate hTERT‐RPE‐1 cells achieve a high degree of RPE functional maturation. Initial experiments exposing RPE cells to oxidant/actinic stress + lutein indicate lutein protects RPE integrity.

Conclusions: This study demonstrates morphological and gene‐expression profile changes in hTERT‐RPE‐1 cells during terminal differentiation. This model’s structural and functional properties characteristic of RPE cells in vivo suggest it’s unique, to date, utility and value for in vitro studies of RPE pathophysiology, including lutein/zeaxanthin effects and metabolism.
Ablation of DHRS3 is associated with alterations in retinoic acid metabolism and signaling and with defects in developmental programming in mice (39.8)
Authors: Moise Alexander , Billings Sara , Pierzchalski Keely , Butler Tjaden Naomi , Pang Xiao‐Yan , Kane Maureen , Trainor Paul
Published: June 2021

Background: The levels of the signaling molecule all‐trans‐retinoic acid (ATRA) are tightly controlled at the level of enzymes involved in its synthesis and degradation. Previous studies have implicated the retinaldehyde reductase DHRS3 in establishing a negative feedback mechanism to limit the formation of ATRA during zebrafish development.

Objective: Here, we investigate the physiological role of DHRS3 in the regulation of embryonic levels of ATRA by characterizing a mouse deficient in this enzyme.

Results: Lack of DHRS3 leads to increased levels of ATRA and decreased levels of retinol and retinyl esters in Dhrs3‐/‐ embryos. Furthermore, accumulation of excess ATRA in Dhrs3‐/‐ embryos is accompanied by alterations in ATRA signaling and defects in developmental programming. Dhrs3‐/‐ embryos die late in gestation and display defects in cardiac outflow tract formation and in atrial and ventricular septation. In addition, Dhrs3‐/‐ embryos also exhibit defects in skeletal development and palatogenesis. The extensive effects of Dhrs3 ablation are also consistent with its widespread expression pattern. Our studies also reveal that Dhrs3 is expressed in many embryonic and adult tissues in which ATRA metabolism and ATRA signaling play important roles, and its expression is responsive to vitamin status.

Conclusion: Our studies demonstrate that DHRS3 is a pivotal enzyme in the regulation of ATRA formation during embryogenesis, and we establish the Dhrs3‐/‐ mouse as a new model to study the pathogenic mechanisms of ATRA‐induced embryopathy.

Grant Funding Source: Supported by NIH grants: P20 GM103420‐10 (A.R.M), HHSN272202000046C (M.A.K.), R01DE016082 (P.A.T.)
Are fruits and vegetables used to sweeten commercial baby foods in the U.K.? (393.2)
Authors: Garcia Ada , McLean Kimberley , Parrett Alison , Wright Charlotte
Published: June 2021

A majority of UK commercial baby foods contain fruit and/or vegetables. We aimed to investigate the fruit and vegetable (F&V) content of commercial baby foods and how these contribute to sugar content.

All foods produced by 8 manufacturers for the UK market in May 2013 were surveyed and 329 foods with F&V in the name identified. Food labels were used to determine which F&V were included and their sugar content.

The most frequent first‐listed fruits were apple (22% of products), banana (12%), mango (7%) and strawberry (5%); the most frequent vegetables were tomato (9%), carrot (6%), sweet potato (6%) and squashes (5%). The total F&V content varied from <20g/100g for 37 (11%) foods to 105 (32%) with >80g. Most foods (84%) were spoonable purees, 44% had names suggesting they were savoury and 51% sweet foods (5% unclear). The 128 sweet purees had a mean ± SD (g/100g) sugar content of 10.9 ± 2.6 while the 39 sweet finger foods had 25.7 ± 17; the 133 savoury purees had sugar content 2.7 ± 1.3 and the savoury dry foods 6.9 ± 3.7. For all foods F&V content was significantly related to the sugar content, and this explained 33% of the variance in sugar content for the spoonable savoury foods and 65% for sweet finger foods.

The vegetables used in baby foods are predominantly sweet and will not encourage preferences for non‐sweet vegetables. F&V contribute significantly to sugar content, suggesting that they are primarily used to sweeten baby foods.

Grant Funding Source: Supported by University of Glasgow
Organ engineering using decellularized liver scaffold recellularized with iPSC‐derived hepatocytes (398.10)
Authors: Kanagavel Vidhya , Ren Songyang , Ignatius Irudayam Joseph , Xiong Weidong , Talavera Dodanim , Klein Andrew , French Samuel , Arumugaswami Vaithi
Published: June 2021

Liver transplantation is the option for end‐stage liver diseases. Shortage of donor liver organ is a major issue. To overcome this, alternative approaches including hepatic cell transplantation, bioartificial liver devise and whole liver organ engineering are being investigated. We focus on developing engineered liver using natural liver scaffold generated via decellularization process. The liver scaffold would maintain the authentic three‐ dimensional micro‐architecture and vasculature. The liver scaffold repopulated with patient‐specific hepatic cells differentiated from induced pluripotent stem cells (iPSC) is a promising option. For this proof‐of‐concept study, we decellularized rat liver by perfusing detergents SDS and Triton x‐100. Histological analysis of decellularized liver matrix (DLM) revealed removal of cellular component and preservation of extra‐cellular architecture. Presence of collagen type IV and laminin in the DLM was verified. Human endothelial cells seeded through DLM portal vein present in the vascular linings. We have also established an efficient protocol for deriving functional hepatic cells from iPSC. Perfusion of DLM with green fluorescent protein labeled iPSC‐hepatocytes resulted in recellularization of liver parenchymal space. Currently, we are assessing the in situ functions of repopulated iPSC‐hepatocytes. In conclusion, we have generated natural liver scaffold from rat that can be populated with human iPSC‐hepatocytes and endothelial cells.
C/EBPα and C/EBPβ mediated genome‐wide combinatorial transcriptional regulatory dynamics during early onset of liver regeneration and chronic alcohol intake (398.6)
Authors: Patra Biswanath , Kuttippurathu Lakshmi , Hoek Jan , Vadigepalli Rajanikanth
Published: June 2021

The primary objective of this study is to characterize effects of chronic alcohol consumption on genome‐scale transcriptional regulatory network dynamics during the early phase liver regeneration after 70% partial hepatectomy (PHx) at 6h post 2/3rd PHx in the rat. Rats were fed liquid diet containing 36% of total calories derived from ethanol for 5 weeks, controls were pair‐fed an isocaloric liquid diet with carbohydrate replacing ethanol. Genome‐wide binding targets C/EBPα and C/EBPβ were detected by ABI SOLiD sequencing approach and qPCR validation.

Our results reveal C/EBPα binding to promoters of metabolic regulator genes, cell cycle inhibitors, glucose transporter, dehydrogenase and reductase family member, RNA metabolic, phosphate metabolic genes, etc. C/EBPβ was detected at the gene promoters of key regulatory pathways such as regulation of cell cycle, regulation of programmed cell death, regulation of cAMP biosynthetic process, positive regulation of RNA metabolic process, MAPK signaling, Insulin signaling, cell adhesion, etc. We performed qPCR validation of a set of genomic loci with increase in C/EBPα and C/EBPβ activity in the ethanol versus control group. We used our PAINT and TRANSFAC bioinformatics software to predict combinatorial regulatory modules containing co‐localized binding sites for C/EBPα and C/EBPβ, on key genes promoter regions. Support: K05 AA017261, and T32 AA007463.
Transdifferentiation of hepatocytes to biliary epithelial cells requires expression of reprogramming factor Oct3/4 (398.8)
Authors: Bhave Vishakha , Bowen William , Donthamsetty Shashikiran , Orr Anne , Michalopoulos George
Published: June 2021

Transdifferentiation of liver epithelial cells (hepatocytes and biliary cells) into each other provides a rescue mechanism in liver disease under situations where either cell compartment fails to regenerate by itself. The mechanisms underlying such transdifferentiation of terminally differentiated epithelial are not known. Recently we reported that adult rat liver expresses reprogramming factors Oct3/4, Nanog, and KLF4, and their expression is important for hepatocyte proliferation and liver regeneration. To test if reprogramming factor Oct3/4 plays a role in transdifferentiation of hepatocytes to BECs, we used the hepatocyte organoid culture: an in vitro hepatocyte to biliary transdifferentiation model. In this model, primary hepatocytes when plated on collagen coated roller bottles and cultured in presence of HGF, EGF, and dexamethasone, transdifferentiate to form BECs between 6‐8 days in culture. We found that Oct3/4 is upregulated at day 6 in this model as assessed by mRNA and protein levels suggesting its possible involvement in transdifferentiation. When expression of Oct3/4 was blocked in hepatocytes using adenovirus containing Oct shRNA, there was a significant decrease in appearance of biliary cells (compared to controls) as assessed by biliary marker HNF1‐beta, strongly supporting the role of Oct3/4 in transdifferentiation of hepatocyte to biliary epithelial cells. Experiments to investigate mechanisms through which Oct3/4 might regulate transdifferentiation are under way.

Grant Funding Source: 1. Pathology Post‐doctoral Research Training grant, 2. Center for chronic diseases of aging grant
Hepatocyte‐like cells derived from mesenchymal stem cells for translational research in the pig (398.9)
Authors: Brückner Sandra , Stock Peggy , Tautenhahn Hans‐Michael , Winkler Sandra , Dollinger Matthias , Christ Bruno
Published: June 2021

Extended liver resection is the only therapeutic option of liver cancer. Yet, the residual liver may not accomplish the regenerative capacity needed, which leads to acute liver failure. Mesenchymal stem cells (MSC) differentiated into hepatocyte‐like cells might provide compensation. Therefore, we characterized porcine MSC from adipose tissue and bone marrow and their hepatocyte differentiation potential for functional liver support in the porcine model.

Mesenchymal surface antigens and multi‐lineage differentiation potential of porcine MSC were assessed by flow‐cytometry. Morphology and functional properties were determined during differentiation and compared with primary‐porcine‐hepatocytes.

MSC from adipose tissue and bone marrow express the typical mesenchymal markers CD44, CD29, CD90, CD105. MSC displayed differentiation into osteogenic and adipogenic lineage. Glycogen storage was comparable in adipose tissue‐ and bone marrow‐derived cells. Urea synthesis was lower in visceral than in subcutaneous adipose tissue‐derived MSC. Cytochrome P450 activity increased during differentiation and was higher in hepatocyte‐like cells generated from bone marrow as from adipose tissue.

The hepatocyte differentiation of porcine adipose tissue‐derived MSC was shown for the very first time. That makes them good preclinical candidates for supportive approaches after liver resection in the pig.
Role of the acetylcholine signaling system in human non‐small cell lung cancers (405.3)
Authors: Brown Kathleen , Lau Jamie , Thornhill Brent , Perry Haley , Stevenson Cathryn , Rollyson William , McNees Christopher , Stover Cody , Dasgupta Piyali
Published: June 2021

Clinical studies show that smoking correlates to 65% of non‐small cell lung cancer cases (NSCLC) in the United States. Nicotine, the major addictive component of cigarettes, accelerates proliferation of human NSCLCs via nicotinic acetylcholine receptors (nAChRs). However, the molecular pathways underlying the proliferative effects of nicotine are yet to be fully understood. The endogenous ligand for nAChRs in neuronal cells is acetylcholine (ACh). Here we show that human lung adenocarcinomas (LAC) produce ACh and contain all of the cholinergic system proteins, including acetylcholinesterase (AChE), choline acetyltransferase (ChAT), choline transporter 1 (CHT1), vesicular acetylcholine transporter (VAChT) and nAChRs. In addition, human LACs isolated from patients showed robust expression of ChAT and VAChT. Nicotine increased the production of ACh in human LAC cells. BrdU assays revealed that ACh acts as a growth factor for human LACs. Nicotine elevated the expression of VAChT and ChAT while downregulating the level of AChE in human NSCLCs. Our study shows that nicotine‐induced ACh production is one of the mechanisms by which nicotine promotes the proliferation of NSCLCs. Our data raise the possibility that that disruption of cholinergic signaling may have applications in the therapy of NSCLCs.

Grant Funding Source: Supported by the Flight Attendant Medical Research Institute YCSA Grant and an NIH R15‐AREA Grant
Structural basis of transmembrane voltage sensing (470.1)
Authors: Li Qufei , Wanderling Sherry , Perozo Eduardo
Published: June 2021

The transduction of electric fields into protein motion plays an essential role in the generation and propagation of cellular signals. Voltage‐sensing domains (VSD) carry out these functions through reorientations of discrete gating charges in the S4 helix. The voltage sensitive phosphatase from C. intestinalis (Ci‐VSP) is controlled by a standard VSD with high sequence similarity to the S1‐S4 segments found in Na+ and K+ channels. To address some of the fundamental questions regarding how membrane proteins sense transmembrane voltages, we have pursued structural and biophysical information on Ci‐VSP’s isolated VSD, under conditions that stabilize the Up and the Down conformations. These will be discussed in the context of explicit mechanisms for voltage sensing.
Tumor suppression by mitotic quality control (472.1)
Authors: Rape Michael
Published: June 2021

Posttranslational modification with ubiquitin, a reaction referred to as ubiquitylation, is essential for accurate cell division and differentiation in all eukaryotes, and accordingly, the aberrant regulation of ubiquitylation enzymes is one of the most frequent causes for tumorigenesis. Ubiquitylation enzymes synthesize different types of modifications, such as polymeric ubiquitin chains of distinct topology, and depending on the type of the ubiquitin mark, ubiquitylation can differentially regulate the activity, localization, or stability of critical cell cycle regulators. Unfortunately, most ubiquitylation enzymes have not been paired with their important substrates and the biological consequences of most ubiquitin marks remain poorly understood. As a consequence, powerful strategies to target ubiquitylation enzymes for therapeutic benefit have not been developed. Here, I will discuss recent progress in identifying new ubiquitylation enzymes and determining their functions in cell cycle control. Our findings have revealed an intriguing role for ubiquitylation in ensuring proper assembly of oligomeric complexes required for cell division, and accordingly, loss of the processes identified in this work can lead to tumorigenesis. Our work, therefore, identifies an important role for mitotic quality control in tumor suppression.
Substrate degradation by the 26S proteasome (478.2)
Authors: Martin Andy , Matyskiela Mary , Beckwith Robyn , Nyquist Kristofor , Worden Evan , Estrin Eric , Lander Gabriel
Published: June 2021

The eukaryotic 26S proteasome utilizes a complex set of coordinated processing steps for the ATP‐dependent degradation of ubiquitin‐tagged substrates. Our cryo‐EM studies reveal important features of the proteasome regulatory particle, including a pronounced spiral‐staircase arrangement of its heterohexameric ATPase ring, that facilitate substrate engagement and degradation initiation. Substrate engagement induces a translocation‐competent conformation, in which the de‐ubiquitinating subunit Rpn11 is repositioned to function as a gatekeeper at the entrance of the processing pore and the ATPase ring adopts a distinct spiral‐staircase configuration, suggesting that highly coordinated ATP‐hydrolysis events drive substrate translocation. Optical tweezers single‐molecule studies of a related protease, ClpXP, further support such a coordinated ATP‐hydrolysis mechanism. Systematic mutational analyses of the proteasome ATPase ring, using a heterologous expression system and in‐vitro reconstitution of 26S holoenzymes, indicate that the six ATPase subunits play distinct roles in substrate engagement and translocation, corresponding to their positions in the spiral‐staircase arrangements of the ATPase ring. Furthermore, structural and mutational studies of Rpn11 provide new mechanistic insights into the translocation‐dependence and regulation of substrate de‐ubiquitination.
The use of the iCollaborative’s Pre‐Health Collection online resources to enhance competency development in undergraduate pre‐health and STEM students (530.2)
Authors: Jakubowski Henry , Zapanta Laura , Page Jen
Published: June 2021

Online educational resources, whether used either in exclusively online courses such as massive open online courses (MOOCS) or more traditional or blended courses as supporting educational resources, must be both high quality and user‐friendly to promote student learning. Characteristics of high quality web resources include common metadata to tag content, balancing expert and community definitions of quality to provide a curated collection of resources, and input from both submitters and users whose comments can evolve the quality of the collection.

The Pre‐health Collection, a new addition to MedEdPORTAL’s iCollaborative (an established, free and open access platform provided by the Association of American Medical Colleges that is dedicated to the sharing of innovations that are being developed, implemented and tested within the health education) meets these characteristics. The Pre‐health Collection instructional materials are cataloged by instructional methodology, format type, and student competencies that will be tested in the new MCAT2015 exam and that are also embraced by other organizations such as the American Society for Biochemistry and Molecular Biology and the American Chemical Society. These competencies move past prescribed content to higher order reasoning and inquiry skills articulated by leaders in science education reform. The organization and use of the collection will be presented.