bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic Pathways in Congenital Heart Development
Authors: Seidman Christine
Published: June 2021

Congenital heart disease (CHD) is the most common birth defect in newborns. Although insights into the genes and pathways involved that cause CHD have been identified by targeted perturbations of molecules that function in the developmental pathways involved in myocyte specification, differentiation or cardiac morphogenesis, the direct role of these or other perturbations in humans has remained poorly understood. Researchers have tried to bridge this knowledge gap through conventional genome‐wide analyses of rare Mendelian CHD families and by sequencing candidate genes in CHD cohorts. While these discoveries have yield highly penetrant inherited mutations in families with mild to moderately severe CHD, analyses of these genes rarely defines a pathogenic mutation in severe forms of CHD that occurs as a sporadic event, the most common presentation of CHD. The advent of contemporary genomic technologies including SNP arrays, next‐generation sequencing, and CNV analyses are accelerating the discovery of genetic causes of severe and sporadic CHD. Remarkably, emerging genomic data have validated and extended earlier observations leaned from the experimental CHD models and monogenic CHD families. Together these dataset have begun to define the genetic architecture of CHD: CHD gene encode molecules that orchestrate cardiac development; CHD mutations alter gene/protein dosage; comparable CHD mutations yield many distinct malformations, implying that higher order interactions account for particular CHD phenotypes.
CarbonQuest: Unfolding the Map of Seed Metabolism
Authors: Alonso Ana Paula , Cocuron Jean‐Christophe , Koubaa Mohamed , Ross Zach , Kimmelfield Rebecca
Published: June 2021

In view of our rapid growing demands on vegetable oil, enhancing fatty acid synthesis in maize (Zea mays) represents tremendous nutritional and economic benefits. In corn kernels, the endosperm and the embryo are the main site for synthesis and accumulation of starch and oil, respectively. So far, breeding efforts to achieve elevated oil content in maize resulted in smaller endosperm and therefore lower yield. We hypothesize that the key to increasing oil content in maize kernels without affecting the yield lies on directly changing their carbon metabolism. To test our hypothesis, we compared the intracellular metabolite levels in maize embryos from two different maize lines, Alex synthetic (Alex) and LH59, which accumulate 48 and 34% of oil, respectively. The comparative metabolomics highlighted the metabolites and pathways that were active in maize embryos and important for oil production. The contribution of each pathway to fatty acid synthesis in terms of carbon, reductant and energy provision was assessed by measuring the carbon flow through the metabolic network (13C‐Metabolic Flux Analysis) in developing Alex and LH59 embryos to build maps of carbon flow through central metabolism. Our approach combined mathematical modeling with biochemical quantification to identify metabolic bottlenecks in fatty acid synthesis in maize embryos. Transgenic maize plants that we generated to overexpress a lead gene increased embryo fatty acid content by 35% without affecting the size of the kernel. This study hence describes the combination of innovative tools that will pave the way for controlling seed composition in important food crops.
Picking the PADlock: Chemical Probes to Study the Protein Arginine Deiminases
Authors: Thompson Paul
Published: June 2021

The Protein Arginine Deiminases (PADs) are a small family of human enzymes that catalyze the post‐translational hydrolysis of arginine residues to generate citrulline. These enzymes are important regulators of gene transcription and their activity is upregulated in multiple inflammatory diseases, including rheumatoid arthritis, ulcerative colitis, and cancer.

Herein, I will discuss our efforts to develop chemical probes targeting the PADs and protein citrullination, focusing on our success in validating the PADs as therapeutic targets, as well as our more recent efforts to develop phenylglyoxal based reagents that can be used to readily visualize protein citrullination and identify disease biomarkers. Additionally, I will describe our efforts, both crystallographic and enzymological, to understand how calcium regulates the activity and nuclear localization of PAD2.
Positive Feedback Regulation in Histone Demethylases
Authors: Fujimori Danica
Published: June 2021

Histone demethylases are chromatin‐modifying enzymes that antagonize lysine methylation. Despite their crucial roles in regulating transcription in physiology and disease, the mechanisms by which demethylases are regulated on chromatin are largely unknown. This is particularly the case for the jumonji subfamily of demethylases, the most recently discovered family of epigenetic enzymes. The need to mechanistically dissect the function of these enzymes rests on evidence that jumonji demethylases are important regulators of transcription in development and differentiation, and that several of these enzymes act as oncogenes.

By investigating the regulation of catalysis in demethylase KDM5A, we have uncovered a novel allosteric mechanism that regulates the activity of this enzyme. Specifically, we demonstrated that binding of the product of demethylation catalysis to one of three PHD reader domains in KDM5A strongly stimulates the catalytic activity of this enzyme. Our findings expand the function of reader domains in jumonji demethylases beyond their canonical function in the recruitment. The unprecedented functional coupling between a PHD domain liganded with the demethylation product and a catalytic domain reveals positive feedback regulation and provides a mechanism by which demethylation could spread on chromatin.
Structure and Function of the Protein Arginine Kinase McsB
Authors: Clausen Tim , Broch Trentini Débora , Suskiewicz Marcin
Published: June 2021

Across evolution, cells adapt their proteome in response to internal and external signals. A simple model of such a process is provided by the heat‐shock response in Gram‐positive bacteria. Importantly, the temperature‐induced adaptation at the transcriptional level is preceded and indeed caused by post‐transcriptional modifications of the existing protein pool. The central player here is the protein kinase McsB that is known to phosphorylate and regulate certain heat‐shock transcription factors.

McsB is of great interest for at least two reasons. First, McsB is the only protein kinase shown to phosphorylate arginine residues and, consistently, displays no homology to classic protein kinases. Second, owing to its importance for the virulence of notorious Gram‐positive pathogens such as Staphylococcus aureus and given its unique protein kinase mechanism, McsB represents a promising pharmacological target.

In order to investigate the function of McsB, we determined a series of X‐ray structures revealing the molecular mechanism of protein arginine phosphorylation in great detail. This mechanism is not only strikingly different from that of canonical protein kinases, but also is under control of an allosteric coupling between the two protomers of the McsB dimer, as phosphoryl‐transfer at one subunit triggers the product release at the other. Accompanying in vitro and in vivo functional studies of McsB shed further light on its mechanism and elucidate its biological role in coordinating the bacterial heat‐shock response.
The Aggregation Mechanism of Amyloidogenic Proteins Involved in Neurodegenerative Disorders
Authors: Stultz Collin
Published: June 2021

Aggregation of intrinsically disordered proteins plays an important role in the pathogenesis of a number of neurodegenerative diseases. Aggregation in vitro occurs in two phases: a lag‐phase, where nuclei that seed aggregation are formed, and a growth phase, where existing amyloid fibrils are elongated. To explore the early stages of nucleation we conducted all atom simulations in explicit solvent of an amyloidogenic peptide derived from the non‐amyloid‐β component of α‐synuclein. Simulations were notable for the rapid formation of a helical multimer that unfolds and refolds on the microsecond timescale. During unfolding, monomers in the oligomeric unit sample extended states consistent with a β‐strand. From these data we derive a model for the nucleation of amyloidogenic peptides where β‐sheets form in a stepwise manner via the association of extended monomers arising from unfolding of a dynamic helical oligomer. Secondly, to explore factors that affect the process of fibril growth we computed the free energy associated with disordered Amyloid‐β (Aβ) monomers being added to growing amyloid fibrils using extensive molecular dynamics simulations coupled with umbrella sampling. We find that the mechanism of Aβ fibril elongation includes the formation of an obligate on‐pathway β‐hairpin intermediate that hydrogen bonds to the fibril core. In addition, these data lead to new hypotheses as to how fibrils may serve as secondary nucleation sites that can catalyze the formation of soluble oligomers – a finding in agreement with recent experimental observations. In sum, these observations provide a detailed mechanistic description of fundamental processes underlying the formation of pathogenic neurotoxic aggregates.
Microbiome Resilience during Inflammation
Authors: Goodman Andrew
Published: June 2021

Human gut microbial communities are subject to numerous perturbations, including dietary changes, exposures to antibiotics and toxins, and pathogen infection. We are developing genetic tools to identify and characterize the mechanisms these microbes use to persist in the perturbed gut environment. Our results suggest that single genes can determine the resilience of commensal bacteria during inflammation. Such factors may provide important insights into the dynamics of recurrent pathogen infection and efforts to introduce stable beneficial microbes into the gut.
The Proprotein Convertases: Cell Surface and Extracellular Matrix Remodeling
Authors: Seidah Nabil , Essalmani Rachid , Kim Woojin , Welsh Ian , Kurpios Natasza
Published: June 2021

The family of proprotein convertases (PCs) comprises 9 secretory serine proteinases. The first 7 PCs (PC1, PC2, Furin, PC4, PC5, PACE4 and PC7) cleave secretory substrates at basic residues, while SKI‐1/S1P and PCSK9 cleave at non‐basic residues. Analysis of the phenotypes of knockout (KO) mice allowed the definition of the in vivo roles of the PCs, revealing specific functions in a tissue‐ and time‐dependent manner during development and in adults. PC5 KO mice die at birth and exhibit alterations in multiple organs. Some of these abnormalities were related to the lack of processing of proGDF11, a major regulator of the anterior‐posterior axis during development. However, GDF11‐independent anomalies were also observed in the small intestine, one of the major organs of PC5 expression. Analysis of PC5 substrates in cells revealed that while Furin activates cell surface adhesion molecules such as N‐cadherin, PC5 inactivates it. Furthermore, protein‐C and glypican‐3 (Gpc3) are activated by PC5, Furin and PACE4. Since both N‐cadherin and Gpc3 play major roles in extracellular matrix remodeling during gut development, we analyzed the impact of the lack of PC5 during the development of the gut at embryonic days 10‐18. Amazingly, PC5 KO mice exhibited abnormal looping of the gut, where midgut and dorsal mesentery morphogenesis are clearly impacted. We've identified a similar gut and mesentery phenotype in Wnt5a mutants, as Gpc3 likely facilitates Wnt5a transport or frizzled receptor interaction to direct asymmetric midgut development. Analysis of the gut of PC5 KO mice revealed the lack of protein expression of Gpc3, suggesting that PC5 is needed to either stabilize the protein or prevent its degradation. Our data show that PC5 regulates gut development by remodeling the extracellular matrix.
Pseudoenzymes as Activators of Enzyme Function: The Prozyme Paradigm in Trypanosomatid Polyamine Metabolism
Authors: Phillips Margaret
Published: June 2021

The parasitic protozoa Trypanosoma brucei is the causative agent of human African trypanosomiasis (HAT). Polyamine metabolism is a proven drug target for the treatment of HAT as eflornithine, an inhibitor of the key biosynthetic enzyme ornithine decarboxylase, is a frontline therapy for late stage disease. Our studies have uncovered an exciting and novel mechanism for regulation of polyamine biosynthesis in the trypanosomatids. We have demonstrated that two enzymes in the pathway, S‐adenosylmethinione decarboxylase (AdoMetDC) and deoxyhypusine synthase (DHS), are activated by oligomerization with catalytically dead paralogs we term prozymes. The trypanosomatids are the only organisms where this mechanism is used to generate the functional forms of both of these enzymes, and while all metazoan genomes contain evidence of “pseudo enzymes”, some with regulatory roles, the sheer magnitude of the enzymatic activation (1000‐3000‐fold) observed for these trypanosomatid enzymes is unprecedented. Additionally in the case of AdoMetDC, changes in AdoMetDC activity levels in the parasite lead to increases in the prozyme protein levels, correlated to the levels of decarboxylated AdoMet, suggesting that regulation of prozyme expression is a novel mechanism for controlling polyamine levels in these parasites. Our finding that this mechanism evolved twice within the same pathway also suggests that the trypanosomatids are under selective pressure to evolve novel mechanisms of regulation, perhaps because of the lack of transcriptional and other mechanisms typically used in eukaryotes to regulate gene expression.
Mechanisms of microRNA‐Mediated Gene Silencing
Authors: Mac Rae Ian , Schirle Nicole , Sheu‐Gruttadauria Jessica
Published: June 2021

MicroRNAs (miRNAs) are small (~22 nt) regulatory RNAs that control expression of thousands of genes in plants and animals. miRNAs function by guiding Argonaute proteins to complementary sites in messenger RNAs (mRNAs) targeted for repression. We determined crystal structures of human Argonaute‐2 (Ago2) bound to a defined guide RNA with and without target RNAs representing miRNA recognition sites. These structures suggest Ago2 uses a stepwise mechanism for target recognition, in which Ago2 primarily exposes guide nucleotides 2–5 for initial target pairing. Pairing to nt 2–5 promotes conformational changes that expose guide nt 2–8 and 13–16 for further target recognition. Interactions with the guide‐target minor groove allow Ago2 to interrogate target RNAs in a sequence‐independent manner, while an adenosine binding‐pocket opposite guide nt 1 further facilitates target recognition. Three tandem tryptophan binding sites in the Ago2 PIWI domain mediate recruitment of silencing factors, ultimately leading to the repression of targeted mRNAs.
Role of microRNAs in Vascular Development
Authors: Hata Akiko , Jiang Xuan , Hart Daniel , Lagna Giorgio
Published: June 2021

microRNAs (miRNAs) interact in a complex way with many coding RNAs, noncoding RNAs (ncRNAs) and proteins. Their expression, processing and functional activity, like that of coding genes, are tightly controlled in order to maintain homeostasis. Aberrant expression of miRNAs can contribute to various human disorders and developmental defects. The biogenesis of a miRNA is a stepwise process that includes (i) transcription, (ii) nuclear cropping, (iii) export to the cytoplasm, and (iv) cytoplasmic cropping. The RNase III enzyme Drosha is responsible for nuclear cropping, which transforms long primary miRNA transcripts (pri‐miRNAs) into intermediate products known as precursor‐miRNAs (or pre‐miRNAs). To examine the role of miRNAs in vascular development and function, we have examined vertebrate animals downregulated in Drosha. Downregulation of Drosha in zebrafish results in angiogenesis defect, suggesting an essential role of miRNAs in vascular development and integrity.
Weird Ion…Weird Ion Channels Mediating Resistance to Fluoride Toxicity
Authors: Miller Christopher , Turman Daniel
Published: June 2021

F‐ specific ion channels of the newly discovered “Fluc” family act as F‐ exporters protect many microorganisms from the toxic effects of this environmentally pervasive halide. The channel is constructed as an four‐TM helix dual‐topology homodimer, in which the two subunits adopt antiparallel orientation within the membrane. We previously used fibronectin domain‐based “monobodies” selected by phage display methods to establish this unusual membrane architecture, showing that these small proteins block single Fluc channels from either side of the membrane. We now ask whether the two blocking sites on opposite sides of the membrane can both be occupied simultaneously by monobodies. Our analysis examines the dependence of single‐channel block‐times as a function of monobody concentration varied symmetrically on the two sides of the channel. If both sides can be blocked symmetrically, a linear blocking scheme should be followed:
Open ‐‐‐‐ Block(1) ‐‐‐‐Block(2),

Where both blocked states are nonconducting. This scheme makes quantitative predictions for the increase in block‐times with monobody concentration that provide information about any cooperativity, negative or positive, that may operate between the two sites.
MCAT 2015 and the Academy: Undergraduate, Graduate and Health Professional Ramifications
Authors: Brenner Charles
Published: June 2021

MCAT is a significant driver of undergraduate education because so many students start college with premedical inclinations. Annually, ~500k US students take general chemistry, 165k take organic chemistry, 45k apply to medical schools, 19k matriculate to medical schools, and 18k receive the MD. Because the vast majority of students who begin in the premedical track do something else besides medicine, care should be taken to develop coursework and curricula that effectively educate students in the molecular sciences and keep their options open. The MCAT was last revised in 1991 when it was possible for a skilled molecular biologist to determine human genotypes at 4 genetic loci. Today, a company offers genotyping for 1.2 million SNPs for @99 direct to consumers. In addition, the epidemics of obesity and type 2 diabetes have the potential to drastically alter health care as we know it. These changes in medicine demand a more educated first year medical student, who will need at least a semester of undergraduate biochemistry. In 2012, Dagmar Ringe and I developed the ASBMB premedical curriculum recommendations, which call for molecular genetics inside of the biology requirement, data analysis inside of the laboratory course requirement, a new course in life‐oriented organic chemistry, and 1‐2 semesters of biochemistry. Now armed by data from over 24,000 students who took MCAT 2015 practice questions, we are able to update the Experimental Biology community on student performance vis a vis foundational concepts in biochemistry. We describe changes in undergraduate, graduate, medical and health professional education that are driving substantive changes in biochemistry teaching across the academy.

Brenner, C & Ringe, D ASBMB Today 12, n. 3, p. 12, 2012

Brenner, C BAMBED 41, p. 1, 2013

Brenner, C J Chem Ed 90, p. 907, 2013
Acculturation, Dietary Behaviors, and Body Mass Index among Vietnamese American Adults
Authors: Lam Carolyn , Jasti Sunitha
Published: June 2021

Objective

To examine the association of acculturation level with dietary behaviors and body mass index (BMI) in adult Vietnamese Americans.

Methods

A cross‐sectional online survey assessed acculturation level using the Suinn‐Lew Asian Self Identity Acculturation Scale (SL‐ASIA), dietary behaviors, and the BMI of 257 adult Vietnamese Americans across America.

Results

Mean (SD) age was 24(8.45) years, BMI 22.9(4.46) and acculturation 3.08(0.46) on a scale of 1‐5. Vietnamese Americans with lower acculturation scores (<3.1, median) were more likely to report higher consumption of non‐starchy vegetables (p<0.005) and green‐leafy vegetables (p<0.035) than more acculturated Vietnamese Americans. Female gender and being married were also associated with healthier dietary behaviors.

Conclusion

Public health campaigns promoting increased consumption of fruits and vegetables targeted to male, unmarried and more acculturated Vietnamese Americans may be beneficial to this population.
Whole Wheat‐supplemented Diet Prevents Risk Biomarkers of Cardiovascular Diseases in Obese Diabetic Mice
Authors: Mohanty Indira , yuan Jialing , Noratto Giuliana , Balemba Onesmo , Morris Craig
Published: June 2021

Cardiovascular disease (CVD) is the number one cause of death around the world.

Our objective was to investigate if whole wheat consumption can delay or prevent the onset of CVD.

Obese diabetic (db/db) mice were fed with standard or whole‐wheat supplemented diets ad libitum for eight weeks. The lean counterpart controls were fed standard diet. At the end of the study blood and heart tissues were analyzed for protein expression of risk markers for CVD using standard biochemical and molecular biology procedures.

Results show that whole wheat consumption decreased biomarkers of oxidative damage in blood including reactive oxygen species levels in blood erythrocytes and protein carbonyls in plasma. This was accompanied by lower plasma levels of proinflammatory cytokine interleukin‐6 which contribute to endothelial dysfunction in obesity. Accordingly, the nuclear factor‐κB (NF‐κB) pro‐inflammatory transcription factor and NF‐κB‐target TNF‐α were downregulated in heart tissues. The downregulation of inflammatory markers in heart tissues might be correlated with decreased abdominal, subcutaneous, and heart adipose tissues and adipokine resistin, which plays a key role in the alteration of immune and inflammatory processes that favor metabolic disorders and atherosclerosis development. Overall, these results strongly support that whole wheat consumption mitigates the obesity‐induced inflammation and metabolic disorders that promote the onset of CVD.
Induction of Mitochondrial Tri‐carboxylic Acid Cycle is Sustained in Mice with Nonalcoholic Steatohepatitis (NASH)
Authors: Kalavalapalli Srilaxmi , Patterson Rainey , Nautiyal Manisha , Mathew Justin , Martinez Janie , Garrett Timothy , Cusi Kenneth , Sunny Nishanth
Published: June 2021

Nonalcoholic fatty liver disease (NAFLD) is a major public health problem in 70% of obese humans, with 20 to 40% progressing to NASH. Tri‐carboxylic acid (TCA) cycle in the liver is critical to macronutrient metabolism, free radical generation and inflammation. We have shown that hepatic TCA cycle is induced in humans and mice with NAFLD. We hypothesized that NASH will impair TCA cycle activity. Mice (C57/BL6) were fed high trans‐fat diet (TFD) for 8 wks. to induce NAFLD and 24 wks. to induce NASH. In vivo fasting hepatic fluxes were measured by stable isotopes and NMR isotopomer analysis. Hepatic ceramides and diacylglycerols were determined by LC‐MS/MS based targeted metabolomics. Hepatic mitochondrial fluxes remained unchanged in mice with NAFLD. However, hepatic fluxes (µmoles/ min) of glucose production (4.1 ±0.4 vs. 5.8 ±0.5), TCA cycle (2.6 ±0.5 vs. 5.4 ±0.6) and anaplerosis (9.1 ±1.2 vs. 16.9 ±2.2) were elevated (P < 0.05) in mice with NASH. Induction of TCA cycle during NASH was concurrent with increase in several ceramides and diacylglycerols, suggesting inefficient oxidation of fatty acids by the liver. In conclusion, increased activity of TCA cycle and high levels of ‘lipotoxic’ metabolites may hasten inflammation and fibrosis during NASH. Support: Research Opportunity Seed Fund Award, UF (N.S.)
Pleiotropic Effects Of GCKR And ABCG2 On Serum Levels Of Uric Acid And Triglycerides In Hispanic Children
Authors: Voruganti V Saroja , Chittoor Geetha , Laston Sandra , Haack Karin , Cole Shelley , Comuzzie Anthony , Butte Nancy
Published: June 2021

Uric acid is the end product of purine metabolism in humans. Elevated SUA levels have been associated with health conditions such as obesity, insulin resistance, metabolic syndrome (MetS), diabetes, hypertension and cardiorenal disease. Our aim in this study was to assess the shared genetic effects on SUA and components of MetS in Hispanic children of the Viva La Familia Study. We previously reported significant heritabilities for SUA and MetS components. A variance components‐based genetic analysis was performed using SOLAR. We genotyped 80 single nucleotide polymorphisms (SNPs) that were selected based on their association with SUA in adults of various populations. The association of these SNPs with MetS components and SUA was estimated using a measured genotype analysis accounting for family relationships. A strong association was found for ATP‐binding cassette sub‐family G member 2 (ABCG2) SNP rs2231142 (p < 8 x 10‐4) and glucokinase regulator (GCKR) SNPs rs1260326, rs780093 and rs780094 (p < 2 x 10‐3) with SUA and triglycerides. No shared genetic effects were found between SUA and other MetS components. For rs2231142, the minor allele (A) was associated with lower levels of SUA and higher triglycerides. For all GCKR SNPs, minor alleles (A) were associated with lower levels of SUA as well as triglycerides. In summary, our study shows that GCKR and ABCG2 SNPs exhibit pleiotropic effects on SUA levels and triglycerides indicating novel shared genetic mechanisms underlying these two phenotypes in Hispanic children.
Soy Flour Muffins Do Not Improve Risk Factors for Cardiovascular Disease in Adults with Hypercholesterolemia
Authors: Padhi Emily , Hawke Aileen , Blewett Heather , Wolever Thomas , Duncan Alison , Ramdath Dan
Published: June 2021

Soy may reduce cardiovascular disease (CVD) risk by lowering LDL cholesterol (LDL‐C), but it is not known whether this health benefit is related to the matrix of soy foods. This study assessed the dose‐dependent LDL‐C lowering effect of muffins made with whole de‐fatted soy flour in addition to other CVD risk factors. In a double‐blind, parallel, multicentre clinical trial, healthy adults (n = 243) with elevated LDL‐C (蠅 3.0 and 蠄 5.0 mmol/L) were randomly assigned to consume daily for 6 weeks either: (1) two soy muffins (25g soy protein); (2) one soy and one wheat muffin (12.5g soy protein and 12.5g whey protein); or (3) two wheat muffins (25g whey protein, control). A one‐way ANOVA determined the effect of treatment on the net change in fasting plasma lipids, C‐reactive protein (CRP), glucose, insulin, insulin resistance (HOMA‐IR), and blood pressure. Analyses were performed by intention‐to‐treat. Participants had a mean (±SD) age of 55.0±8.8 years and were overweight (BMI: 28.0±4.6 kg/m2). No significant net change in LDL‐C was found in the groups assigned to soy compared to control (0.01±0.05 mmol/L vs. ‐0.04±0.05 mmol/L vs. ‐0.04±0.05 mmol/L; p = 0.718). Further, there were no significant intervention effects on other CVD risk factors. Whole de‐fatted soy flour muffins do not lower LDL‐C and other CVD risk factors in hypercholesterolemic adults. Funded by the Government of Canada Growing Forward I Science Substantiation Program (RBPI#1746).
Relations to Cognitive Change with Age of Micronutrients Found in Green Leafy Vegetables
Authors: Morris Martha Clare , Booth Sarah , Dawson‐Hughes Bess , Barnes Lisa , Bennett David , Wang' Yamin
Published: June 2021

Consumption of green leafy vegetables has been reported to reduce cognitive decline in older adults. We investigated the relations to cognitive decline of various micronutrients for which green leafy vegetables are a rich dietary source, including phylloquinone (vitamin K), folate and carotenoids (lutein, lycopene, beta‐cryptoxanthin, alph carotene, beta carotene), in a cohort study of 954 participants of the Memory and Aging Project, mean age 81 years, 75% female. Diet was assessed by a 144‐item semi‐quantitative food frequency questionnaire. Energy‐adjusted nutrients were modeled in quintiles. Cognition was assessed annually by a battery of 19 tests. Nutrient intakes were related to change in cognitive function over a mean 4.5 years using linear‐mixed models adjusted for age, sex, education, and participation in cognitive activities. Higher green leafy vegetable consumption was associated with slower cognitive decline (β=0.033, SE=0.010, p=0.001). In analyses of micronutrients, we observed slower rates of cognitive decline for food folate (Q5 vs Q1 β=0.044, p=0.004), phylloquinone (Q5 vs Q1 β=0.040, p=0.001), lutein (Q5 vs Q1 β=0.039, p=0.001), and total beta carotene (Q5 vs Q1 β=0.029, p=0.01). No associations were observed for lycopene, alpha carotene, or beta‐cryptoxanthin. Cognitive decline in older adults may be slowed through the consumption of green leafy vegetables rich in folate, phylloquinone, lutein and beta carotene.

Supported by grants R01 AG031553 and R01 AG17917
Serum Micronutrient Status during Pulmonary Exacerbation and Following Recovery in Adults with Cystic Fibrosis
Authors: Lee Moon Jeong , Smith Ellen , Ziegler Thomas , Alvarez Jessica , Tangpricha Vin
Published: June 2021

Objective

Patients with cystic fibrosis (CF) may be at risk for micronutrient depletion, particularly during periods of acute illness and infection. The purpose of this study was to investigate serum micronutrient status over time in adults with cystic fibrosis hospitalized with a pulmonary exacerbation.

Methods

This was an ancillary study of a multi‐center trial investigating the role of high‐dose vitamin D supplementation in adults with CF. We measured serum micronutrient concentrations in subjects during a pulmonary exacerbation (baseline) and again three months later. Serum calcium (Ca), copper (Cu), iron (Fe), potassium (K), magnesium (Mg) and sulfur (S) concentrations were measured using inductively‐coupled plasma‐atomic emission spectrometry. Statistical analyses included paired t‐tests.

Results

Subjects were 24 hospitalized adults with CF (mean age 28.4 ± 7.4 yr). At baseline, CF subjects exhibited significantly lower mean serum concentrations of Ca (9.8 ± 0.8 vs. 10.8 ± 2.0 mg/dL, p<0.05), Cu (1.5 ± 0.6 vs. 1.6 ± 0.6 μg/mL, p<0.05), and Fe (0.8 ± 0.3 vs. 1.3 ± 1.1 μg/mL, p<0.05) compared to levels obtained 3 months following the pulmonary exacerbation. Serum concentrations of K, Mg, and S did not change over time. (K: baseline, 4.9 ± 0.3 vs. three months, 5.1 ± 0.5 mEq/L; Mg: 1.8 ± 0.2 vs. 2.0 ± 0.3 mg/dL; S: 1288.6 ± 343 vs. 1309.9 ± 290 μg/mL; p>0.05 for all).

Conclusions

Serum concentrations of calcium, copper and iron increased significantly several months following recovery from acute pulmonary exacerbation in adults with CF. This may reflect decreased inflammation, improved food intake and/or increased absorption following recovery.

Supported By: CF Foundation and National Institutes of Health
Parental Awareness of Calorie Recommendations for Children
Authors: Lynskey Vanessa , Anzman‐Frasca Stephanie , Hubbard Kristie , Harelick Linda , Sharma Shanti , Economos Christina
Published: June 2021

On average, school‐age children (5‐12 years) should consume 蠄600 kcal per lunch/dinner (L/D) meal. Parental awareness of this recommendation is critical to prevent overconsumption and ensure effective use of posted kcal information, which will become widely available under the Affordable Care Act. In 2014 Harris Interactive/Nielsen was commissioned to administer a nationally‐representative online survey to parents of children aged 5‐12 in the US to assess awareness of the recommendation. A total of 1,207 parents completed the survey (58.0% female; mean age 40.9 years). Sampling weights based on socio‐demographics were incorporated in all analyses. In response to an open‐ended question about how many kcal a “typical child aged 5‐12 years” should consume per L/D meal, only 27% of parents answered accurately (defined as 600±100 kcal). 72% of these respondents were somewhat (32%) or very (40%) unsure of their answer, while 28% were somewhat (24%) or very (4%) sure. Non‐Hispanic parents (OR: 1.93, 95% CI: 1.33, 2.79), male parents (OR: 1.42, 95% CI: 1.10, 1.84), and parents in the highest income bracket (OR: 2.68, 95% CI: 1.72, 4.16) were more likely to answer accurately than were Hispanic parents, female parents, and parents in the lowest income bracket, respectively. Ongoing analyses are exploring additional demographic differences to inform efforts to address health disparities. Results demonstrate that most parents are unaware of kcal recommendations per L/D meal for school‐age children, suggesting that parent education is needed to improve awareness and maximize the impact of expanded menu labeling. Targeted strategies may be needed to reach certain demographic subgroups so that such efforts address, rather than widen, health disparities. JPB Foundation, RWJF
Glucagon‐like peptide 2 and epidermal growth factor promote intestinal adaptation in two neonatal intestinal failure models
Authors: Koepke Jacob , Lim David , Wales Paul , Wizzard Pamela , Sigalet David , Li Julang , Turner Justine , Levesque Crystal
Published: June 2021

This study assessed the efficacy of exogenous GLP‐2 and EGF therapy, alone and in combination, on ileal gene expression in two translational piglet models of neonatal short bowel syndrome: a 75% mid‐intestinal resection (JI model) or a 75% distal‐intestinal resection including removal of the ileo‐cecal junction (JC model). JI and JC piglets (age 3‐5 days) received one of 4 treatments (saline, GLP‐2, EGF and GLP‐2+EGF) for 7 days after surgical modification. Expression of genes related to tissue repair (trefoil factor 3, TTF3), cell proliferation (ki‐67), differentiation (cdx2), and apoptosis (caspase 3, c3), digestive enzymes (intestinal alkaline phosphatase, IAP), and tight junction proteins (claudin 7 and 15) were assessed. The CONTRAST statement was used to compare the saline with the treatment groups within each model. In JI pigs, administration of GLP‐2 and EGF, alone or in combination increased (p<0.05) expression of TFF3 and claudin ‐7 and ‐15 and tended to increase (p=0.08) IAP expression. There was no effect of treatment on ki‐67, cdx2, or c3 expression. In JC pigs, administration of GLP‐2 and EGF, alone or in combination tended to increase (p=0.06) expression of TTF3 and claudin‐15 but there was no effect of treatment on expression of on ki‐67, cdx2, IAP, c3, or claudin‐7 expression. Regardless of the surgical model, GLP‐2 and EGF therapy promote tissue repair and barrier function.
Disruption of Tight Junction Barrier Function and Upregulation of Inflammatory Signaling Pathway in a Necrotizing Enterocolitis Mouse Model
Authors: Ravisankar Srikanth , Tatum Rodney , Herco Maja , Chen Yan‐Hua
Published: June 2021

Necrotizing enterocolitis (NEC) is a leading cause of death in preterm infants. Neonates weighing <1500 grams are at highest risk for the disease, with a prevalence of 7% and mortality up to 30%. Despite advancements in neonatal medicine, this disease remains a challenge. To study the molecular mechanism underlying NEC, we produced a mouse NEC model to examine the tight junction integrity and epithelial barrier function in NEC intestines. Three‐day old C57BL/6 mouse pups were fed with 50 µl of 33% Esbilac formula every 3 hours and then asphyxiated twice daily (100% N2 for 60 sec) followed by cold stress at 4°C for 10 minutes. Dam fed pups from the same litter served as controls. Pups were sacrificed 96 hours later. Successful induction of NEC was confirmed by histopathology. Western blot analysis revealed the increased expression levels of tight junction protein claudin‐2 and ‐7, while claudin‐3 expression level was decreased in the NEC intestines compared to those of controls. In addition, NF‐kB and TGFβ expression levels were also upregulated, suggesting the activation of the inflammatory signaling pathway in the NEC intestines. More importantly, we found that the tight junction in NEC intestines was leaky since the biotin tracer molecules were diffused from lumen into the tissue through the intercellular space. We conclude that there is a loss of tight junction barrier function and alteration of tight junction claudin proteins in the intestines of NEC mouse model. This work is supported by a research fund from Department of Pediatrics, BSOM at ECU and National Institute of Health grant HL085752.
Co‐administration of a Grape Seed Procyanidin Extract and the Bile Acid Sequestrant, Cholestyramine, Results in Beneficial Metabolic Alterations, Including Decreased Triglyceride Levels
Authors: Heidker Rebecca , Caiozzi Gianella , Ricketts Marie‐Louise
Published: June 2021

Bile acid (BA) sequestrants, used to lower cholesterol levels, may be taken alone or in combination with cholesterol‐lowering medication. We previously showed that grape seed procyanidin extract (GSPE) reduces enterohepatic BA recirculation as a new mechanism to reduce serum triglyceride (TG) levels. This study aimed to determine the effects of co‐administering an acute dose of GSPE with the BA‐binding resin cholestyramine (CHY) on TG levels and BA homeostatic gene expression.
Eight‐week old C57BL/6 mice were treated for 4 weeks with a control diet, or a 2% CHY‐supplemented diet, after which, they were administered vehicle or GSPE (250mg/kg) for 14 hours. Tissues were harvested and gene expression levels were analyzed via qPCR. Biochemical analysis was performed to assess serum BA and TG levels. Data were analyzed using one‐way ANOVA.
Results show that CHY‐GSPE co‐administration reduces intestinal IBABP (61%, p<0.0001) and FGF15 (99.5%, p<0.0001) expression, relative to control. In addition serum BA levels were decreased 74% (p<0.0001), while hepatic CYP7A1 expression was increased 13‐fold (p<0.0001), indicative of increased BA synthesis. SREBP1c expression was reduced 42% and serum TG levels were decreased 34% in the CHY‐GSPE group, compared to control.
We present novel evidence showing that GSPE works synergistically with CHY to lower serum TG levels, which is achieved via enhanced de novo BA biosynthesis.
AKAP9, a Regulator of Microtubule Dynamics, is Essential for Remodeling of the Blood‐Testis Barrier
Authors: Venkatesh Deepak , Mruk Dolores , Herter Jan , Cullere Xavier , Cheng Yan , Mayadas Tanya
Published: June 2021

The blood‐testis barrier (BTB) is formed by tight, adherens and gap junctions between adjacent Sertoli cells of the seminiferous tubules. The BTB undergoes extensive remodeling during the seminiferous epithelial cycle of spermatogenesis to allow the transport of preleptotene spermatocytes from the basal compartment to the adluminal compartment for further development. The actin cytoskeleton serves unique structural and supporting roles in this process, but little is known about the role of microtubules and their regulators in BTB remodeling. The cAMP responsive scaffold protein AKAP9 has been shown to regulate microtubule dynamics. We demonstrate that conditional and inducible deletion of AKAP9 in mice after the initial formation of the BTB leads to infertility despite evidence of germ cell meiosis. AKAP9 deletion results in marked alterations in the integrity of microtubules in Sertoli cells, mislocalization of gap and tight junctional molecules at the BTB and a progressive loss of barrier integrity despite normal localization of F‐actin at the BTB. These changes were accompanied by an arrest of meiosis and spermiogenesis. Unexpectedly, barrier integrity and meiosis were restored in older AKAP9 deficient animals. Yet, significant defects in spermiogenesis persisted suggesting a role for AKAP9 in the transport of developing spermatids across the adluminal compartment during spermiogenesis. These results suggest that AKAP9 is critical for both dynamic restructuring of the BTB during the epithelial cycle and subsequent spermiogenesis.
Discrete Functions Of GSK3α And GSK3β Isoforms In Prostate Tumor Growth And Micrometastasis
Authors: Gao Fei , Al‐Azayzih Ahmad , Shenoy Somanath P.R.
Published: June 2021

Objective

Role of glycogen synthase kinase‐3 (GSK3) in cancer is controversial and the isoform specific function of GSK3 in cancer is not well defined. The present study aims to explore the discrete functions of GSK3α and GSK3β in prostate cancer growth and metastasis.

Methods and Results

We report that silencing the expression of GSK3α or GSK3β isoforms inhibit overall growth and proliferation of the metastatic prostate cancer cells with a predominant role of GSK3α isoform in the process. Deficiency of GSK3α, but not GSK3β inhibited colony formation by the PC3 and DU145 metastatic prostate cancer cells, and the growth of PC3 tumor xenografts in athymic nude mice. Despite the modest effect of GSK3β knockdown on the cell proliferation in vitro, knockdown of GSK3α, but not GSK3β resulted in reduced proliferation and enhanced apoptosis in tumor xenografts in vivo. ShRNA‐mediated knockdown of GSK3α and GSK3β equally inhibited the ability of PC3 cells to migrate and invade the endothelial‐barrier in vitro, and micrometastasis in vivo. Mechanistically, whereas silencing GSK3α resulted in increased expression of pro‐apoptotic markers cleaved caspase‐3 and cleaved caspase‐9 in both PC3 and DU145 cells, silencing GSK3β resulted in the inhibition of cell scattering, establishment of cell‐cell contacts, increased expression and membrane localization of β‐catenin, and reduced expression of epithelial to mesenchymal transition (EMT) markers such as Snail and MMP‐9 indicating specific role for GSK3β in EMT, and acquisition of motility and invasive potential.

Conclusions

The isoform specific role of GSK3α and GSK3β in prostate cancer cells in vitro, and tumor growth and micrometastasis in vivo, via distinct molecular and cellular mechanisms.
Role of CD47 in CD4+ T cell Proliferation after TCR Stimulation
Authors: Azcutia Veronica , Newton Gail , Bassil Ribal , Khoury Samia , Elyaman Wassim , Luscinskas Francis
Published: June 2021

CD47 is involved in adaptive immune responses and leukocyte homeostasis. Han and colleagues (JEM 209:1325, 2012) have reported that CD47‐/‐ mice are protected from (MOG)35‐55 peptide induced experimental autoimmune encephalomyelitis (EAE), but not from passive EAE, suggesting a defect in the immune cell compartment. They concluded a defect in T cell proliferation due to failed T cell activation. We also observed CD47‐/‐ are not susceptible to MOG‐induced EAE, and have reduced CD4 T cell proliferation after MOG immunization in vivo and MOG‐dependent recall proliferation assay in vitro. However, in our hands CD47‐/‐ T cells from MOG‐immunized mice express identical levels of surface activation markers (CD69, CD44, IL2R, PD‐1) vs WT cells, and similar levels of intracellular cytokine production. CD47‐/‐ T cells also have defective Ag independent expansion after TCR stimulation, even though proximal signaling events (p‐Lck, p‐ZAP‐70, p‐ERK1/2) are identical to WT cells using FACS and CyTOF mass spectrometry. Intriguingly, kinetics of CD47‐/‐ T cell proliferation and cell cycle analyzed by CSFE dye dilution and by DNA staining respectively, show a comparable proliferative response to WT cells in the first 48h, but fail to proliferate beyond day 3. Accordingly, CD47‐/‐ CD4 T cells show a 2.3 fold increase in Annexin‐V staining and a 40% reduced [H3]thymidine incorporation vs WT. In summary, CD47‐/‐ CD4 T cells become activated by MOG or TCR stimulation, but fail to maintain clonal expansion. We suggest this is due to defects in cell cycle machinery and/or increased cell apoptosis. This work was supported by NIH P01HL03628 and AHA 11POST7730055.
A 4‐Month Intervention with Daily Consumption of Yellow Cassava by Kenyan School Age Children Does Not Affect Thyroid Function Negatively
Authors: Melse‐Boonstra A , Talsma EF , Gomora Z , Demir A Y , Brouwer ID , Zimmermann MB
Published: June 2021

Cassava is a goitrogenous food due to the presence of cyanide, which interacts negatively with thyroid metabolism. Pro‐vitamin A rich yellow cassava has recently been developed as a biofortification strategy to tackle vitamin A deficiency in poor resource areas. We assessed the effect of daily consumption of white or yellow cassava on thyroid function within a randomized controlled trial conducted among Kenyan school children in an area where cassava is not commonly consumed. School children (6‐13 years) were randomized to three treatment groups: 1) White cassava and placebo supplement (n=113); 2) White cassava and β‐carotene supplement (n=113); and 3) Yellow cassava and placebo supplement (n=109). Urinary iodine concentration (UIC) was assessed at baseline; concentrations of thyrotropin (TSH), thyroglobulin (Tg) and free thyroxine (fT4) in serum were assessed before and after the study; and antibodies of thyroid peroxidase (TPO‐Abs) were assessed after the study. At baseline, median UIC was 622 µg/L, 6% of the children had elevated concentrations of TSH (>5.6 mIU/L), 39% had low fT4 concentrations (<10 pmol/L), and 21% had high concentrations of Tg (>40 ng/L). This remained largely unchanged after the study. Serum concentrations of TSH, fT4 and Tg did not differ between groups after intervention. Only one child had raised TPO‐Abs (>9 IU/ml). The children included in the study had excessively high iodine intake and were hypothyroidic at baseline. Thyroid function did not deteriorate further upon cassava intervention.
Curriculum Content Review: A Guided Collaborative Process in Continuous Quality Improvement
Authors: Poznanski Ann
Published: June 2021

Integrated curricula require diligence in content monitoring. We have developed a guided collaborative review process for Continuous Quality Improvement (CQI) of pre‐clerkship curriculumto ensure that desired content is covered, gaps or unwanted redundancies are eliminated and horizontal and vertical integration occurs. Steps include: (1) Assistant Dean of Curriculum meets weekly with Course Directors and provides self assessment forms based on LCME standards, content outlines and progress tracking sheets; (2) Course Director completes review forms, for both course self‐evaluation and evaluation by Curriculum Committee; (3) Course Committee reviews content; (4) Pre‐clerkship Subcommittee reviews course reports and suggests improvements; (5) Curriculum Committee provides feedback, suggested improvements and deadlines; (6) Curriculum Committee reviews recommended improvements, after completion. Our CQI process united faculty in focused efforts in curriculum development; identifying gaps and unwanted redundancies, scaffolding concepts, developing interdisciplinary, interprofessional and self directed educational experiences and emphasizing behavioral and socioeconomic topics. Course Directors were provided with knowledge and ownership of courses and familiarity with LCME standards.
Convergent evolution towards a permanently descended and mobile larynx in some species of mammals
Authors: Frey Roland , Charlton Benjamin , Reby David , Volodina Elena , Volodin Ilya , Wyman Megan
Published: June 2021

In most mammals the larynx has a high resting position close to the root of the tongue. An exception to this are humans with a descended larynx. Some other species of mammals convergently evolved a permanently descended larynx: red and fallow deer among cervids, Mongolian and goitred gazelle among bovids, lion and tiger among felids, the koala among marsupials. Permanent descent of the larynx involves an elongation of the vocal tract. In addition, the non‐human species convergently evolved a mobile larynx allowing further momentary vocal tract extension during calls. Convergent evolution illustrates selection pressures towards evolution of a descended and mobile larynx in some species of mammals arising from reproduction‐relevant acoustic communication in the respective social systems.