bluuebunny/crossref_metadata_2025 huggingface dataset:
Transcription and Pre‐mRNA processing in space and time
Authors: Neugebauer Karla M.
Published: June 2021

Cells face the challenge of transcribing genes and processing RNA in a limited time period. On the one hand, gene transcription must be completed during interphase, which can be extremely short in cells that divide quickly. On the other hand, RNA processing, which often occurs during transcription or “co‐transcriptionally”, will be affected by gene length and the elongation rate of the RNA polymerase. In certain biological contexts – such as early embryogenesis – numerous genes begin massive transcription all at once, placing high demands on the transcription and processing machineries. Finally, many steps in the eukaryotic gene expression pathway add time to the process, due to RNA transport among cellular compartments. My lab's research addresses the cellular and molecular mechanisms that link transcription and subcellular organization to RNA processing, revealing how gene expression works in a variety of biological contexts. I will report our latest results, deriving from experiments carried out in budding yeast, zebrafish embryos and mammalian cells.
Combinatorial and Temporal Codes within pathogen‐responsive Gene Regulatory Networks
Authors: Hoffmann Alexander
Published: June 2021

How stimulus‐responsive gene expression is specified remains an important unresolved biological question. Studies of model gene promoters advanced the hypothesis of a Combinatorial Code of transcription factors (TFs), and recent observations of stimulus‐specific TF activation dynamics suggested the hypothesis of a Temporal Code. Neither hypothesis has been tested with mammalian transcriptome‐wide measurements, or integrated within a model of signal‐responsive gene regulatory networks (GRNs). Here, I will discuss our recent studies of the pathogen‐responsive gene expression program using the systems biology approach of iterative mathematical modeling and quantitative experimentation. Our findings indicate that predictive models for gene expression cannot be based on nuclear GRNs alone, but must also consider the cytoplasmic, dynamic Signal Regulatory Network (SRN). The described framework allows for the necessary integration of bottom‐up and top‐down systems biology approaches.
Using Small Molecules to Engineer and Explore Human Immunity
Authors: Spiegel David A
Published: June 2021

Antibody‐based therapeutics have become critical instruments in treating diseases ranging from rheumatoid arthritis to cancer. However, antibodies and other therapeutic proteins are limited by their peptide‐based chemical nature: they require intravenous administration, are often highly immunogenic or allergenic, and treatment regimens are often very costly.

This talk describes recent research efforts in our laboratories toward the design, synthesis, and biological characterization of antibody‐recruiting small molecules against prostate cancer, Staphylococcus aureus, and HIV. These are bifunctional molecules designed to redirect antibodies already present in the human bloodstream to the surfaces of pathogenic cells, forming a ternary complex that will lead to immune‐mediated pathogen destruction. In theory, this strategy would exploit many advantages of biologics, while circumventing the disadvantages, by capitalizing on the chemical properties of small molecules (high oral bioavailability, facile synthesis, and low cost).

We hope that this small molecule‐based strategy will serve as a starting point toward entirely novel therapeutic approaches to a wide range of disease states.
Tackling Targets in Epigenetics
Authors: Cole Philip A.
Published: June 2021

Enzyme‐catalyzed reversible post‐translational modifications on proteins, crucial in regulating normal and disease processes in biology, has become an emerging area for drug discovery. Our lab has developed a series of chemically‐based approaches to interrogate the structure and function of the enzymes that regulate protein phosphorylation, acetylation, octanoylation, and lysine methylation. We will describe recent results from these studies highlighting new insights and remaining challenges.
Control of expression of cell wall stress‐induced yeast genes by transcriptional attenuation
Authors: Levin David E , Kim Ki-Young
Published: June 2021

The MAPK Mpk1 of the Cell Wall Integrity signaling pathway uses a non‐catalytic mechanism to activate transcription of cell wall stress‐induced genes by acting as a co‐transcription factor. Mpk1 serves an additional function in transcription elongation that is also independent of its catalytic activity. This function is mediated by an interaction between Mpk1 and the Paf1 subunit of the Paf1C elongation complex associated with RNA Pol II. The Mpk1‐Paf1 interaction blocks recruitment of the Sen1 termination complex to the elongating RNA Pol II, thereby preventing transcriptional attenuation shortly after initiation. Attenuation under non‐inducing conditions appears to be a mechanism to minimize basal expression of stress‐induced genes. However, under inducing conditions, attenuation must be disabled to allow gene expression. Therefore, Mpk1 serves as an attenuation‐relief factor for cell wall stress‐induced genes.

We found additionally that 10% of yeast protein coding genes are subject to Sen1‐mediated attenuation control that is independent of Mpk1 and cell wall stress. This subset is highly enriched for genes induced under various stress conditions, suggesting that transcriptional attenuation is a widespread phenomenon that extends to genes induced in response to a diverse array of stress conditions.
Identifying non‐vitamin & mineral bioactive (non‐VM) ingredients for inclusion in Dietary Supplement (DS) Composition Databases
Authors: Saldanha Leila G , Dwyer Johanna T , Holden Joanne M , Andrews Karen W , Bailey Regan L , Betz Joseph M , Gahche Jaime J , Hardy Constance J , Milner John , Roseland Janet M
Published: June 2021

DSHEA defined DS and permitted addition of non‐VM ingredients if they meet the Act's requirements. Dietary Supplement Ingredient Database (DSID) is a federally funded database that contains analytically derived information on the composition of DS. DSID contains estimates of adult & child multi‐VM supplements (MVMs). Addition of over‐the‐counter (OTC) prenatal MVMs & omega‐3 fatty acid supplements to the database is in‐progress.

Objective

Develop a plan for including non‐VM ingredients in DSID.

Method

The DSID working group identified 41 non‐VM ingredients of interest. The criteria to rank and prioritize the 41 bioactives were existence of studies or safety concerns, public exposure, federal research priorities, and availability of validated analytical methods and analytical reference materials. Public health significance, previously used to rank VM ingredients, was not scored due to lack of data. The top 11 ingredients were: CoQ10, garlic, saw palmetto, ginkgo biloba, glucosamine, ginseng, green tea catechins (EGCG and other catechins), milk thistle, echinacea, flaxseed, and turmeric (curcumin).

Conclusion

Obtaining input from the research community on which of these non‐VM ingredients should be incorporated into DSID and deciding on whether and how to report data for constituent levels not declared on the product label, i.e., proprietary formulas. (Funding Office of Dietary Supplements, NIH)
Dietary intake of overweight and obese children attending a weight‐loss program
Authors: Kranz Sibylle , Brauchla Mary , Garant Amanda , Gupta Sandeep
Published: June 2021

Low diet quality is associated with the risk of overweight/obesity in adults but limited data is available on the effects in children. To improve the understanding of the role of diet on childhood obesity, we conducted a cross‐sectional observational pilot study in 5–11 year oldsattending the the Pediatric Overweight Education and Research Program (POWER) at Riley Hospital for Children, Indiana University, Indianapolis IN. Dietary intake was assessed using two 24‐hour recalls and mean intake of total energy, foodgroups, fiber, macro‐; and selected micronutrients was estimated. Results showed a mean daily intake of 1,503 kcals; 1.8, 1.6, 5.4, 0.9, 2.5 and 1.3 servings of fruits, vegetables, grains, whole grains, dairy, and meat, respectively. Thus, the diets of the children in this study were still deficient in fruits, vegetables, and whole grains, which led to fiber consumption levels below the recommendations. The foods consumed that contributed most of the fiber intake in this population were sweetened ready‐to‐eat cereals, fruits (apples, pears, pineapple, banana), fast‐food pizza, and meat sandwhiches. In conclusion, improving diet quality by increasing intake of fiber‐rich foods could possibly help support the establishing of healthy weight in this population.

Grant Funding Source : Purdue University PDT grant
Paradigm Shift in Graduate Education: A Transdisciplinary Approach to Childhood Obesity Prevention
Authors: Kemmer Teresa M. , Koszewski Wanda M. , Meendering Jessica , Jensen Becky , Fischer Jean Ann
Published: June 2021

The Transdisciplinary Childhood Obesity Prevention Graduate Program (T.O.P.) is designed to avoid the failed silo approach to obesity prevention and advance toward a team‐based participatory approach. The program combines expertise from South Dakota State University (SDSU) and the University of Nebraska‐Lincoln (UNL) in the areas of nutrition, early childhood education, family and consumer sciences, child development, exercise science, nutrigenomics and biostatistics.

Students from a variety of disciplines implement and manage programs and research. The synergistic multidisciplinary team‐based learning approach enables students to foster working relationships and impact children, families, schools and communities. The program prepares students to 1) conduct research on the behavioral, social, biological, and environmental causes of childhood obesity, 2) implement evidence‐based transdisciplinary approaches to prevention, 3) expand understanding of the complex influences associated with excess weight gain and 4) develop and evaluate programs intended to prevent childhood obesity. To address health disparities, students participate in experiential learning opportunities in minority, underserved populations. Students graduate with a Master's or Doctoral degree from their respective college and obtain a T.O.P certificate. Funding: USDA NIFA Competitive Grants 2011□67002□30202.
Manipulative Dexterity and Handgrip Strength are Associated with Greatest Difficulty with Multiple Meal Preparation/Consumption Tasks in Homebound Seniors
Authors: Sharkey Joseph R.
Published: June 2021

Select manual tasks are necessary to prepare and consume meals. Although these tasks – opening cans, milk/juice cartons or jars, lifting a cup, and opening plastic, frozen, and single‐serving packages – are important for independent living, the relationship of both manipulative dexterity (MD) and grip strength (HG) to greatest difficulty in these tasks has not been explored in homebound seniors who rely on home‐delivered meals. This study examined data from the baseline in‐home assessment of MD, HG, self‐reported difficulty with meal preparation/consumption tasks (MPCT), and demographic and health‐related characteristics in a randomly recruited sample of 345 homebound seniors who received home‐delivered meals (81% female, 49% Black, age 78.28.4 y, 58% lived alone). Almost 25% of the sample reported the greatest difficulty with ≥2 MPCT (range 0–7 MPCT). Using adjusted logistic regression, the odds for reporting 2 MPCT were greater for older adults with lowest tertile of MD performance (OR 2.4, 95% CI 1.24–4.62), lowest sex‐specific tertile of HG (OR 2.4, 95% CI 1.31–4.56), being female, or using medications from ≥5 therapeutic categories (OR 2.2, 95% CI 1.12–4.25). The results suggest that future efforts target improvement in MD and/or grip strength. In addition, food packaging should be evaluated to limit difficulty for individuals with limitations in MD or HG.
New Waist Circumference Cut‐offs for African Americans (AA) According to the Clustering of Metabolic Syndrome (MetS) Risk Factors, NHANES 1999–2006
Authors: Udahogora Margaret , Jackson Robert
Published: June 2021

Although central obesity is highly associated with MetS criteria, reliable cutoff values for waist circumference (WC)1 independent of BMI2 are still lacking among African Americans. We determined the gender specific cut‐off values of WC, which optimally predict the clustering of two or more MetS risk factors in AA. The study consisted of 2136 females and 1908 males (NHANES3 ‐ 1999–2006). The MetS components were defined according to the NCEP/ATPIII4 criteria. The WC values were tested using receiver operating characteristics analysis (ROC)5. The Youden Index and the minimum distance values from the upper left corner of the ROC curve were calculated to determine the WC thresholds with optimal sensitivity and specificity. The mean age of subjects was 46 years ranging between 20–85 years with a BMI of 29.9 ± 7.4, in the range of 15.8–67.3 kg/m2, and a WC of 98.5 ± 16.9, in the range of 60.4–163.1cm. The WC cut‐off values were 94.7 cm with 76% sensitivity and 67% specificity for males and 97.6 cm with 70% sensitivity and 61% specificity for females. For the early detection and management of the MetS in AA, the WC of 95 cm for males and 98 cm for females are suggested as appropriate cut‐off values.
The catalytic subunit of DNA‐dependent protein kinase is downstream of ATM and feeds forward oxidative stress in selenium‐induced senescence response
Authors: Rocourt Caroline RB , Wu Min , Chen Benjamin PC , Cheng Wen-Hsing
Published: June 2021

Selenium induces a senescence response through induction of ataxia‐telangiectasia mutated (ATM) and reactive oxygen species (ROS). Although a role for the DNA‐PK complex, including the catalytic subunit of DNA‐dependent protein kinase (DNA‐PKcs), Ku70 and Ku80, in DNA double strand break repair is established, it is unclear how these proteins function in the response to selenium‐induced oxidative stress and senescence induction. In this study we demonstrate that pre‐treating normal human diploid fibroblasts with DNA‐PK kinase inhibitor NU 7026 suppresses selenium‐induced senescence response. Selenium treatment induces phosphorylation of DNA‐PKcs on Thr‐2647 and Ser‐2056, the extent of which is decreased in the presence of ATM kinase inhibitor KU 55933 or the antioxidant N‐acetylcysteine or 2,2,6,6‐tetramethylpiperidine‐1‐oxyl. In contrast, the selenium‐induced phosphorylation of ATM on Ser‐1981 is not affected by NU 7026. Cells deficient in DNA‐PKcs or pre‐treated with NU 7026 or N‐acetylcysteine are defective in selenite‐induced ROS formation. Opposed to DNA‐PKcs, Ku70 and Ku80 are dispensable for selenite‐induced ROS and γH2A.X formation and removal. Taken together, these results indicate a distinct role of DNA‐PKcs from Ku70 and Ku80, in which this kinase can respond to and feed forward selenium‐induced ROS formation and is placed downstream of ATM in the resultant senescence response.
Modulation of cholesterol‐induced hepatic steatosis by macronutrient manipulation in guinea pigs
Authors: de Ogburn Ryan C , Aguilar David , Volek Jeff S , Fernandez Maria Luz
Published: June 2021

We sought to examine the impact of high cholesterol (HChol) on the development of non‐alcoholic fatty liver disease in male guinea pigs and evaluated whether a low‐carbohydrate diet (LCD) could effectively improve hepatic morphology and liver function following a HChol diet. Forty guinea pigs were randomly assigned to consume a HChol (0.25%) (n = 30) or a low‐cholesterol (LChol) diet (0.04%) (n = 10). After 6 wk 20 animals were sacrificed (10 LChol and 10 HChol) and plasma and livers were collected for analysis. Plasma total cholesterol (TC) (290.2 ± 62.27 vs 49.5 ± 11.81 mg/dL), LDL, and HDL were higher in the HChol group (P<0.01). Liver enzymes ALT and AST were also higher in the HChol group and the liver to body weight ratio was higher in the HChol group (P<0.01). Histologically, HChol livers displayed extensive hepatic steatosis while this was not observed in LChol livers. The remainder of the animals were randomly assigned (n=10/group) either to a LCD or high‐carbohydrate (HCD) diet. After 6 wk, no differences in plasma TC or LDL were observed, however AST was higher in guinea pigs fed the HCD and was significantly correlated with plasma TC (r = 0.884, P< 0.05). Additionally, the ratio of liver weight to body weight was positively correlated with plasma ALT only in the HCD group. These results indicate that HChol successfully induces hepatic steatosis and LCD fed guinea pigs appear to have improved liver function relative to HCD.
Effects of an L‐Arginine Infusion on Postprandial Fat Metabolism in Healthy Young Subjects
Authors: Katsanos Christos S , Meyer Christian , Puga Guilherme
Published: June 2021

Activation of the L‐arginine‐nitric oxide pathway is linked to improved lipid metabolism, information largely obtained in animal studies. We sought to determine the effects of an acute increase in plasma L‐arginine concentration on lipid metabolism after fat ingestion in young (age, 23±2 yrs), lean subjects, free of dyslipidemia (N=7). Subjects ingested whipping cream (0.7 g fat/kg body weight) supplemented with [13C]‐triolein in the morning after a 12‐h fast on two separate occasions: 300 ml of 10% L‐arginine (ARG) or saline (SAL) were infused during the first hour after the fat ingestion. Blood samples and expired CO2 were collected before and for eight hours after the fat ingestion. Although plasma insulin concentrations were increased at 1 hour in the ARG trial (42±13 vs 10±2 μIU/ml, P = 0.03), the incremental area under the curve during the entire 8‐hour postprandial period (AUCi0−8h) of insulin did not differ between ARG and SAL trials (3±9 vs 4±4 μIU/ml/hr, P = 0.92). ARG reduced the AUCi0−8h of plasma free fatty acid (FFA) concentrations ~70% (0.45±0.55 vs 1.53±0.35 mmol/l/hr; P < 0.05) but did not significantly alter the AUCi0−8h of plasma triglyceride (TG) concentrations (37±30 vs 91±34 mg/dl/hr; P = 0.37). Further, ARG increased plasma 3‐hydroxybutyrate concentrations ~80% during the last four hours (AUCi4−8h) of the postprandial period (1050±162 vs 574±109 μmol/l/hr; P = 0.06), but did not alter whole‐body oxidation of the ingested fat (246±32 vs 235±18 mg/kg/hr; P = 0.62). We conclude that acute activation of the nitric oxide pathway by L‐arginine infusion, despite only transiently increasing plasma insulin levels, drastically reduces plasma FFA concentrations but not TG concentrations, and increases hepatic but not systemic lipid oxidation after fat ingestion in healthy young subjects.
Nutritionally‐induced neonatal muscle growth retardation can be rescued by sustained muscle IGF‐I expression
Authors: Fiorotto Marta L , Sosa Horacio A , Davis Teresa A , Villegas Carolina , Estrada Irma J
Published: June 2021

Undernutrition prior to the attainment of maturation permanently compromises skeletal muscle mass. To determine if the loss in growth capacity can be overcome by precluding the developmental decline in local IGF expression, transgenic MLC/mIGF‐I mice with muscle‐specific IGF‐I overexpression were studied. From birth, nontransgenic (NTG) and transgenic (TG) littermates were suckled on NTG dams fed either a control 20 % (CP) or an 8% protein (LP) diet. At weaning all pups were fed the CP diet ad libitum and studied 0, 1, 3, and 17 wk later (n=7–9/age/genotype/diet). Hindlimb muscle masses at weaning were 20–25% smaller in all LP compared to CP pups (P<0.001); there was no protective effect of genotype. After 1 wk of refeeding, muscle mass of the LP TG and NTG pups were 6 and 20 % smaller, respectively than those of CP NTG pups. Over this week, food intake of TG and NTG LP pups were similar (2.98±0.08 g/d), but feed efficiency was higher in TG pups (0.39 and 0.33 g body weight/g food, respectively; pSD, 0.021; P<0.001). After 3 wk, muscle weights of LP TG pups were similar to those of CP NTG, and by 20 wk of age they were 20% heavier (P<0.001); LP NTG muscles remained 10% small than in CP NTG mice. The results indicate that the reduced muscle mass produced by undernutrition in early life is reversible provided appropriate anabolic stimuli are present during nutritional rehabilitation. (Supported by NIH AR46308 and USDA/ARS 6250‐51000‐043)
Attenuation of niacin‐induced prostaglandin D2 generation by omega‐3 fatty acids in THP‐1 macrophages
Authors: Siddiqui Rafat Ali , VanHorn Justin , Harvey Kevin A. , Altenburg Jeffrey D. , Xu Zhidong , Kovacs Richard J.
Published: June 2021

The present investigation examined the ability of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), omega‐3 polyunsaturated fatty acids (PUFAs), to attenuate niacin‐induced PGs in THP‐1 macrophages. Niacin induced both PGD2 and PGE2 generation in a dose dependent manner. Niacin also caused an increase in cytosolic calcium and activation of cytosolic phospholipase A2 (cPLA2). The increase in PGD2 and PGE2 was reduced by both DHA and EPA, but not by oleic acid (OLA). Omega‐3 PUFAs efficiently incorporated into cellular phospholipids at the expense of AA, whereas OLA incorporated to a higher extent but had no effect on AA levels. Omega‐3 PUFAs also reduced surface expression of HM74A, a human niacin receptor. Furthermore, omega‐3 PUFAs also inhibited the niacin‐induced increase in cytosolic calcium. Niacin and/or omega‐3 PUFAs minimally affected cyclooxygenase‐1 (COX‐1) activity and had no effect on Cox‐2 activity. The effects of niacin on PGD2 generation were further confirmed using Langerhans dendritic cells. Results of the present study indicate that omega‐3 PUFAs reduced niacin‐induced PG formation by diminishing the availability of their substrate and as well as reducing the surface expression of niacin receptors. In conclusion, our study suggests that the regular use of omega‐3 PUFAs along with niacin can potentially reduce the niacin‐induced flushing response in sensitive patients.
The emerging relationship between the endocannabinoid metabolome, inflammation, and pregnancy
Authors: Durham Holiday A. , Wood Jodi T , Geaghan James P , Makriyannis Alexandros , Keefe Carol J
Published: June 2021

Pregnancy is a natural inflammatory state accompanied by increased body weight and altered glucose metabolism. Endocannabinoids (ENDOs), analogs of fatty acids, play a pivotal role in inflammation and pregnancy outcome. The emerging relationship between the endocannabinoid (ENDO) metabolome and inflammatory mediators (IMs) underlies regulatory events that alter pregnancy. We evaluated the relationship between ENDOs and IMs in normal and overweight (OW) pregnant women with (214 mg of docosahexaenoic acid (DHA, 22:6 n‐3)/day) and without DHA supplementation. In a subset (n=16), we quantified plasma ENDOs (anandamide [AEA], palmitoylethanolamine [PEA], oleoylethanolamine [OEA], docosahexaenoyl ethanolamine [DHEA], 2‐arachidonolglyerol [AG], 2‐ palmitoylglycerol [PG], 2‐oleoyglycerol [OG]) at 20–22, 23–26, 32 and 38–40 weeks using liquid chromotography‐mass spectrometry. The IMs, IL‐6, leptin, C‐reactive protein (CRP) and adiponectin were measured using enzyme‐linked immunosorbent assays. Canonical correlations were used to evaluate relationships between ENDOs and IMs after adjusting for weeks, group and BMI. In this group of women primarily OW prior to pregnancy, there was a positive relationship between measured AEA, PEA, OEA and IL‐ 6, leptin, and CRP (p= 0.001), but not adiponectin. These findings have implications for maintaining a successful pregnancy.
Biomarkers of Nutrition for Development (BOND): An Overview
Authors: Raghavan Ramkripa , Darnton-Hill Ian , Raiten Daniel J
Published: June 2021

Objective

The aim of the BOND program is to harmonize the decision making process about what biomarkers are best for use in support of research, program development and evaluation, and generation of evidence‐based policy.

Methods

Targeted workshops were held to discuss the growing need for nutrient biomarkers. Funding proposal was submitted to support the BOND program and a framework was developed to include a complementary translational and research tracks to further develop specific program activities.

Results

The initial focus of BOND is on 6 case study nutrients: iodine, vitamin A, iron, folate, vitamin B12 and zinc, chosen for their public health importance and unique challenges related to the biomarker agenda. A Query Based System (QBS), which is a renewable and interactive IT resource, was developed to provide customized evidence‐based advice to users with regard to appropriate biomarker(s) for a given use. Nutrient specific expert panels were constituted to review and assess the extant literature and the evidence generated is being applied to the QBS and used to identify research gaps.

Conclusion

A system has been created whereby customized biomarker advice will be available via the QBS. The BOND project will inform the research agenda and lead to new technologies and approaches for biomarker discovery and development.

Support: Bill & Melinda Gates Foundation; PepsiCo; NIH (ODS, DNRC, NICHD)
Nutrition‐related food marketing: a case study of whole grain promotion on breads
Authors: Sumanac Dunja , Mendelson Rena , Tarasuk Valerie
Published: June 2021

With the release of recommendations for increased whole grain consumption, the term ‘whole grain’ is now increasingly appearing on packaged food products in Canada. Manufacturers’ use of this term is voluntary and unregulated, raising questions about the nature of nutrition guidance being provided. To examine the relationship between front‐of‐package (FOP) references and whole grain content, nutritional content and price, we collected nutrition facts table information, ingredient list and price for all breads sold in 3 major supermarket chains in Toronto (n=1,002). Bread was selected for study because it is a staple food, widely consumed, and 55% of products have FOP nutrition‐related marketing. 21% of breads bore a reference to whole grain; this included 51% with whole grain ingredients in the first position meeting USDA or Whole Grains Council criteria, but we could not quantify whole grain content. The presence of a whole grain reference was associated with significantly higher fibre, lower sodium, and higher fat content. Mean price did not differ by presence of a whole grain reference, but few breads with whole grain references fell within the lower tertile of price. Our results suggest that manufacturers’ applications of this term are providing valuable nutrition guidance, but mandatory, standardized information on whole grain content would enable consumers to make more informed purchases. Funded by CIHR.
Dietary Milk Polar Lipids Benefit Gut Barrier Integrity And Lipid Metabolism In C57BL/6J Mice During Systemic Inflammation Induced By Escherichia Coli Lipopolysaccharide
Authors: Zhou Albert Lihong , Ward Robert E. , Hintze Korry J.
Published: June 2021

To explore dynamic interactions among dietary fat, gut permeability and lipid metabolism in the context of systemic inflammation, 3 groups of C57BL/6J mice were fed for 8 weeks: (1) modified AIN‐93G diet (CO); (2) CO with milk gangliosides (GG); (3) CO with milk phospholipids (PL). After 2 weeks’ feeding, animals were injected subcutaneously with Escherichia coli lipopolysaccharide (LPS) endotoxin to induce acute inflammation. Animals were fed for 6 more weeks to observe recovery. Gut permeability was assessed by differential sugar tests at baseline and 24h, 2 week plus 4 week after LPS stress. GG protected intestinal integrity against LPS stress while PL facilitated the recovery of small intestine barrier function. Both GG and PL suppressed colon permeability increase against LPS stress and facilitated barrier integrity recovery while PL had a bigger effect for prevention and GG had a stronger effect for recovery. GG or PL did not affect food intake, weight gain or fasting plasma levels of glucose, cholesterol and triglycerides. Expressions of 13 genes on liver lipid metabolism were assessed by RT‐qPCR. GG increased beta‐oxidation gene ACAA compared with CO & PL. PL suppressed fatty acid synthesis gene ACC and cholesterol synthesis gene HMGCR compared with CO & GG. In general, dietary milk polar lipids may have beneficial effects on gut permeability and lipid metabolism in the context of systemic inflammation.

Grant Funding Source: Western Dairy Center
Using Program Impact Pathways to Improve Anemia Reduction Programs
Authors: Phillips Erica Lyn , Pelletier David , Gervais Suzanne , Stoltzfus Rebecca , Young Sera , Michaud Lesly
Published: June 2021

Recent evidence of the benefits of iron supplementation during pregnancy to reduce low birth weight and maternal mortality highlights the need for iron supplementation in pregnancy, an intervention known to be efficacious. Despite implementation of anemia reduction programs in many developing countries, the worldwide prevalence of maternal anemia in pregnancy remains over 40%. This suggests limitations in program delivery.

To improve the delivery of a large‐scale anemia reduction program delivered through a mobile clinic program in rural Haiti, we designed a “Program Impact Pathway” (PIP) to delineate the mechanisms by which program activities resulted in desired outcomes. Survey data (n=663) from program beneficiaries were used to asses each essential component of the PIP, including consistent distribution of iron folic acid (IFA) at monthly clinics, women's understanding of how and why to IFA and barriers to adherence. Although knowledge about IFA benefits was high, irregular clinic attendance and inconsistent delivery of IFA resulted in a low median number of times women received IFA during pregnancy.

Iron supplementation programs will be successful only if all essential elements linking program efforts to desired outcomes are identified and understood. The PIP provides such a method, and the lessons from its use in Haiti can be applied to other such programs.

Research support: USAID, NIH/NIDDK
Plant cell culture strategies to increase 13C‐enrichment of lycopene for human metabolic tracing studies
Authors: Moran Nancy Engelmann , Conlon Lauren E. , Rogers Randy B. , Lila Mary Ann , Erdman John W. , Clinton Steven K.
Published: June 2021

The red tomato carotenoid lycopene (LYC) and/or its metabolites may contribute to anti‐cancer bioactivity. However, little is known regarding LYC metabolites that are endogenously‐produced or absorbed from foods. To better understand LYC metabolism, tracer LYC was 13C‐biolabeled using tomato cell cultures grown in 13C‐glucose‐ containing media. Biolabeling produces a mixture of 13C‐mass isotopomers. The goal of this work was to shift the enrichment of LYC (C40H56) toward the uniformly labeled ([U]‐13C‐LYC) isotopomer, in order to provide a strong signal for metabolite detection. ‘Ailsa Craig’ hp‐1 cell cultures were grown in 13C‐glucose‐containing media for 1, 2, or 3 serial growth cycles and mass isotopomeric distribution was quantitated by tandem high pressure liquid chromatography (HPLC)‐mass spectrometry. Serially culturing cells for 1, 2, or 3 growth cycles led to [U]‐13CLYC yields of 10, 38, 46 %, respectively, with no deleterious effect on total LYC yield (~5 mg LYC/L culture for each cycle). To optimize harvest timing, HPLC evaluation of media glucose utilization during the labeling cycle indicated 99% of media glucose was incorporated by day 12 of the growth period. These approaches greatly enhance production efficiency of highly enriched a 13C‐LYC tracer for human carotenoid metabolism research.

Grant Funding Source : Pelotonia Postdoctoral Fellowship at OSU and NIH/NCCAM 5R21AT005166‐02
Ablation of stellate cells during liver regeneration blocks mitosis and induces a switch in stellate cell phenotype
Authors: Nejak-Bowen Kari N , Orr Anne V , Bowen William C , Michalopoulos George K
Published: June 2021

Hepatic stellate cells (HSCs) synthesize new hepatocyte growth factor (HGF) during liver regeneration (LR), and also play an important function in matrix production; thus, we hypothesize that HSCs are the master regulators of LR. Rats were injected with either gliotoxin (which induces HSC apoptosis) or DMSO one day before and simultaneous with partial hepatectomy (PH). There were more apoptotic cells in the gliotoxin livers as compared to DMSO livers, as assessed by TUNEL staining. Ki67 staining show the presence of many proliferating cells in the control, while in the gliotoxin‐treated rats, mitosis was absent. Although HGF mRNA expression was unchanged, HGF protein expression was significantly decreased in the gliotoxin livers. Chronic elimination of stellate cells over a period of 5 days after PH also causes decreased proliferation and increased apoptosis. Intriguingly, this treatment induced a switch in HSC phenotype, with higher expression of alpha‐SMA in control rats compared to gliotoxin rats, which had more desmin. Finally, there was a paradoxical increase in both hepatocyte proliferation and apoptosis when HSCs were ablated during the later stages of LR. Thus, gliotoxin treatment at early time points after PH causes a block in proliferation and an increase in apoptosis, while treatment during the latter stages of LR causes a phenotypic change in HSC marker expression and an increase in proliferation.
Hepatocyte Nuclear Factor 4 alpha (HNF4α) Knockdown Stimulates Pro‐Mitogenic Gene Expression in Hepatocytes
Authors: Walesky Chad Michael , Gunewardena Sumedha , Edwards Genea , Apte Udayan
Published: June 2021

HNF4α, the master regulator of hepatocyte differentiation, has been shown to inhibit hepatocyte proliferation via yet to be identified mechanisms. We investigated the mechanisms of HNF4α‐induced inhibition of hepatocyte proliferation using two novel HNF4α knockdown mouse models. Hepatocyte specific deletion of HNF4α resulted in increased hepatocyte proliferation. Comparative global gene expression analysis revealed a set of genes commonly regulated in both HNF4α deletion models. The majority of the down‐regulated genes are known HNF4α target genes involved in hepatic differentiation. Interestingly, many up‐regulated genes were associated with cell proliferation and cancer. HNF4α knockdown mice treated with the known hepatic carcinogen diethylnitrosamine developed a 7‐fold increase in number of tumors, as compared to controls. Furthermore, in vitro over expression of HNF4α in mouse HCC cells resulted in a decrease in cell proliferation along with a decrease in promitogenic gene expression. Taken together these data indicate that HNF4α inhibits hepatocyte proliferation by repression of specific pro‐mitogenic genes.
Role of PINCH in regulating liver size and termination of liver regeneration
Authors: donthamsetty shashi , Mars Wendy , Wu Cary , Michalopoulos George
Published: June 2021

This study investigates the role of PINCH in regulation of liver size and termination of liver regeneration. This protein is a part of the ternary complex known as the IPP (Integrin linked kinase‐ Pinch‐Parvin) complex. We generated PINCH 1 and PINCH 2 double KO mice (referred as PINCH1/2 KO mice). Mice under the above conditions were born normal. However, they develop histologic abnormalities characterized by disorderly hepatic plates, increased proliferation of hepatocytes and biliary cells and increased deposition of extracellular matrix. After a sustained and prolonged proliferation of all epithelial components, proliferation subsides and final liver weight by the end of 30 weeks in livers with PINCH1/2 deficient hepatocytes is 40% larger than the WT mice. These mice when subjected to 70% partial hepatectomy regenerated normally and did not show any termination defect. In conclusion, PINCH is involved in regulating liver size but not terminating liver regeneration.
JAM‐A regulates barrier function through a pathway distinct from that controlling cell migration
Authors: Monteiro Ana C , Ivanov Andrei I , Rankin Carl Robert , Severson Eric A , Nusrat Asma , Parkos Charles A
Published: June 2021

Tight junctions (TJs) are critical for barrier function by controlling the paracellular passage of solutes and preventing influx of toxins and pathogens. We have reported that the TJ protein Junctional Adhesion Molecule A (JAM‐A) regulates intestinal epithelial barrier by dimerization‐dependent signal(s), however the pathway is not understood. Given our previous findings linking JAM‐A to β1 integrin–mediated cell migration through Afadin, PDZ‐GEF2 and Rap1a, we used an siRNA mediated approach to test if these elements were important in JAM‐A regulation of barrier. Here we report that JAM‐A modulates barrier by a pathway distinct from that regulating cell migration. Loss of Afadin, PDZ‐GEF1, and Rap2c but not PDZ‐GEF2, Rap1a/b or Rap2b impaired barrier by a similar extent to that observed with JAM‐A loss. Since Rap2 has not been characterized in the intestine, we also show that Rap2 co‐localizes with JAM‐A at TJs in healthy human colonic epithelium. We conclude that JAM‐A‐mediated regulation of epithelial function is dependent on multiple divergent pathways involving small GTPases and speculate that JAM‐A dependent Rap2c activation regulates barrier through effects on the peri‐junctional cytoskeleton.
Children's Very Low Food Security is Associated with Increased Dietary Intakes in Energy, Fat, and Added Sugar among Mexican‐origin Children (6–11 y) in Texas Border Colonias
Authors: Sharkey Joseph R. , Nalty Courtney , Johnson Cassandra , Dean Wesley R.
Published: June 2021

Background

Food insecurity among Mexican‐origin and Hispanic households is a critical nutritional health issue of national importance. This study assessed the relationship between children's experience of food insecurity and nutrient intake from food and beverages among Mexican‐origin children (age 6–11 y) who resided in Texas border colonias.

Methods

Baseline data from 50 Mexican‐origin children were collected in the home by trained promotora‐researchers. All survey (demographics and nine‐item child food security measure) and 24‐hour dietary recall data were collected in Spanish. Separate multiple regression models were individually fitted for specific nutrients.

Results

Thirty‐two children (64%) reported low or very low food security. Very low food security was associated with greater intakes of total energy and percentage of calories from fat and added sugar.

Conclusions

Such findings have implications at a regional and national level, as the Mexican‐origin population continues to grow along the border and in new destination communities. Child‐reported food insecurity situations could serve as a screen for nutrition problems in children. Further, the National School Lunch and School Breakfast Programs, which play a major beneficial role in children's weekday intakes, may not be enough to keep pace with the nutritional needs of low and very low food secure Mexican‐origin children.
Non‐coding RNAs; epigenetic regulators of gene transcription in human cells
Authors: Morris Kevin V
Published: June 2021

Recent observations have demonstrated that exogenously introduced small antisense RNAs (asRNAs) can transcriptionally modulate gene expression in human cells. The mechanism involved in small asRNA directed transcriptional gene silencing (TGS) appears to involve DNA methyltransferase 3a (DNMT3a). However, an endogenous RNA trigger directing epigenetic regulatory proteins to targeted genomic loci in human cells has remained unknown. We present evidence here suggesting that long non‐coding asRNAs function in human cells as effector molecules driving TGS. These asRNAs, in some cases emanating from pseudogenes, function to guide epigenetic remodeling complexes consisting of Enhancer of Zeste (Ezh2) and DNMT3a to target loci. When these regulatory asRNAs are degraded using RNAi the result can be a concomitant activation of their protein‐coding counter part. Importantly, this RNA based transcriptional regulatory mechanism can be taken advantage of to either transcriptionally silence a genes expression in a long‐term manner or activate a genes transcription by the targeted degradation of the regulatory long antisense non‐coding RNAs.
A Role for microRNAs in Axenfeld Rieger Syndrome and Craniofacial/Tooth Anomalies
Authors: Amendt Brad A. , Cao Huojun , Wang Jianbo , Li Xiao , Gutierrez Diana
Published: June 2021

Mutations in the PITX2 homeobox gene are associated with Axenfeld Rieger syndrome (ARS) and defective PITX2 transcriptional activity affects microRNA expression.

Methods

Conditional knockout and transgenic mice, molecular and biochemical assays reveal molecular mechanisms of specific microRNAs and a regulated network for their expression.

Results

We have identified discrete sets of mircoRNAs expressed at various stages of craniofacial development. Conditional knockout (cKO) of Dicer1 (mature microRNAs) in the dental and oral epithelium using the Pitx2 Cre mice results in multiple and branched enamel‐free incisors, cusp‐less molars and cleft palate. The cervical loop (stem cell niche) is expanded in Dicer1 cKO and epithelial cell differentiation is repressed. PITX2 regulates the expression of microRNAs that target Noggin, a potent BMP inhibitor, Lef‐1/Wnt‐β‐catenin signaling and HMGN2 a chromatin‐associated remodeling factor. PITX2 positively and negatively regulates a novel microRNA‐gene expression network involved in progenitor cell (stem cell) proliferation and differentiation.

Conclusions

PITX2 regulates microRNA expression and microRNAs feedback to regulate PITX2 expression through several novel molecular mechanisms. Support for this research was provided from grants DE13941 and DE18885 from the National Institute of Dental and Craniofacial Research.
Muse cells: a novel type of adult human pluripotent stem cells in mesenchymal tissues and their contribution to tissue repair
Authors: Dezawa Mari
Published: June 2021

We newly found a unique type of stem cells which we named Multilineage differentiating Stress Enduring (Muse) cells (PNAS, 2010). They can be isolated as cells double positive for mesenchymal marker CD105 and human ES cell marker SSEA‐3 from bone marrow, skin, fat tissues and human cultured mesenchymal cells. They express pluripotent stem cell markers, self‐renew and generate cells representative of all three germ layers. Most importantly, they do not show tumorigenic proliferation. When human Muse cells are infused into tail vein of Nog‐mouse suffering from fulminant hepatitis, human Muse cells integrated into mouse liver and differentiated into hepatocyte having an ability to release human albumin into blood stream.

Recently, we found that Muse cells are a primary source of iPS cells in human fibroblasts (PNAS, 2011). When human fibroblasts were separated into Muse and non‐Muse cells and transduced with Yamanaka four factors, iPS cells were generated exclusively from Muse cells, but never from non‐Muse cells. Epigenetic alterations were not seen in non‐Muse cells and some of the major pluripotency markers were not expressed for the entire period of generation.

Thus, Muse cells will be beneficial for cell‐based therapy and biomedical research.
microRNAs in Cardiac Development and Function
Authors: Wang Da-Zhi
Published: June 2021

MicroRNAs (miRNAs) negatively regulate gene expression at the post‐transcriptional level, primarily by base‐pairing with the 3’‐untranslated region (3’‐UTR) of their target mRNAs. Many miRNAs are expressed in a tissue/organ‐specific manner and are associated with an increasing number of cell proliferation, differentiation and tissue development events.

Cardiac muscle expresses distinct genes encoding structural proteins and a subset of signal molecules that control tissue specification and differentiation. The transcriptional regulation of cardiac and skeletal muscle development has been well established, yet only until recently has it been uncovered that miRNAs participate in the regulatory networks.

A subset of miRNAs are either specifically or highly expressed in cardiac and skeletal muscle, providing an opportunity to understand how gene expression is controlled by miRNAs at the post‐transcriptional level in this muscle type. miR‐1, miR‐133, miR‐206 and miR‐208 have been found to be muscle‐specific, and thus have been called myomiRs. Our studies, using a conditional knockout strategy, show that microRNAs are essential for proper development and function of the heart. We further demonstrated that miR‐1 and miR‐133 play a vital role in myocyte proliferation and differentiation. Gain‐ and loss‐of‐function studies identify miR‐208a an important regulator of cardiac remodeling in response to stress.

The discovery of myomiRs as a previously unrecognized component in the regulation of gene expression adds an entirely new layer of complexity to our understanding of cardiac, skeletal muscle development and function. Investigating myomiRs will not only reveal novel molecular mechanisms of the miRNA‐mediated regulatory network in cardiac and skeletal muscle development, but also raise new opportunities for therapeutic intervention for cardiovascular diseases.
Dietary L‐carnitine results in greater energy expenditure and a lower RQ in overweight, but not lean, adult cats
Authors: Shoveller Anna Kate , Minikhiem Debbie Lee , Brewer Jason , Foy Julie , DiGennaro Joe
Published: June 2021

L‐carnitine (LC) is included in weight loss diets to reduce hepatic lipidosis that often accompanies weight loss in cats; however, a majority of cats are fed maintenance diets. The objective of this study was to assess supplemental dietary LC (100 ppm) in a maintenance diet (17.8% fat, 35% protein) fed to adult cats. Twenty cats (2–4 yrs, 4.41 ± 0.34 kg BW) received a control (CON) diet for 3 wks. Calorimetry was performed at the end of the 3‐wk washout following an overnight fast and for 15 hr post feeding. After, cats were allocated to CON or CON + LC and fed to maintain BW for 42 d. Calorimetry was performed on d 21 and 42 of feeding. BW did not differ between treatments at baseline and throughout the study. On d 14 and 42, AUC for energy expenditure (EE) and respiratory quotient (RQ) were not different between treatments for lean cats (body condition score (BCS)≤3.0), but moderately overweight cats (BCS > 3.0) fed LC had greater AUC EE for the entire 15 hrs post feeding at d 21 and 42 and a lower AUC RQ from 0 – 210 minutes post feeding on d 42. These results suggest that dietary LC results in greater EE and lower RQ in overweight, but not lean, cats fed to maintain weight. Supported by P&G.
Occupational formaldehyde exposure and cancer risk
Authors: Freeman Laura Beane
Published: June 2021

Formaldehyde is a highly reactive, colorless gas that is used as a disinfectant and preservative and in numerous industrial applications, including the manufacture of a variety of products. The long‐term effects of formaldehyde exposure have been evaluated in epidemiologic studies. Occupational epidemiology studies have been conducted primarily in two areas, the medical and funeral services professions, and industrial and manufacturing settings. Several studies, including a large cohort study of formaldehyde exposed workers conducted by the National Cancer Institute found an increased risk of nasopharyngeal cancer, a rare tumor, in workers with high formaldehyde exposure compared to those with no exposure. Early surveys of formaldehyde‐exposed occupations, including funeral directors, embalmers, pathologists and anatomists conducted in the 1980s also showed increased mortality from leukemia and other lymphohematopoietic malignancies among these occupations. Results from the NCI‐led cohort study also indicated increased risk of leukemia with increasing formaldehyde exposure, with the strongest associations for myeloid leukemia. Recently, the International Agency for Research on Cancer classified formaldehyde as a carcinogen for its association with nasopharyngeal cancer and leukemia. The U.S. National Toxicology Program also classified formaldehyde as a carcinogen in its 12th Report on Carcinogens.