bluuebunny/crossref_metadata_2025 huggingface dataset:
Persistence of an Adverse Metabolic Phenotype in Parenterally Fed Neonatal Pigs
Authors: Burrin Douglas , Stoll Barbara , El-Kadi Samer , Genovese Kenneth , Davis Teresa , Fiorotto Marta , Thymann Thomas , Sangild Per
Published: June 2021

The nutritional environment during fetal and neonatal life is a key determinant affecting the risk for adult‐onset diseases, such as diabetes and obesity. We previously showed that chronic parenteral (PN) compared to enteral (EN) nutrition in neonatal pigs for two weeks leads to increased glucose intolerance, insulin resistance and fat deposition. Our aim was to test whether glucose intolerance, insulin resistance and fat deposition in the liver and body persist into late infancy and adolescence. Term newborn pigs, were fed PN or EN (N=12/group) for 2 wk followed by ad lib feeding of a high‐fat (30%) and sucrose (20%) diet for 5 mon. Body composition was measured by dual‐emission X‐ray absorptiometry at 2 wk, 8 wk, and 5 mon, and serum chemistry and fasting intravenous glucose tolerance test (IVGTT; 1 g glucose/kg x sample 90 min) were obtained at 5 mon. At 2 and 8 wk of age, body weight was similar, but % fat was higher and % lean was lower in PN vs EN pigs. At 5 mon, there were no differences in serum markers of liver injury or lipidemia, however, the 90‐min area‐under‐curve (AUC) for both glucose and insulin were lower (p<0.05) in PN than EN pigs, but the ratio of AUC insulin:glucose was not different between groups. We conclude that PN during the neonatal period increased adiposity transiently into early infancy but PN‐induced glucose intolerance was not sustained into adolescence even when challenged with an obesogenic diet.
Relationship between exercise and high fat diet with oxidative stress parameters in the immune system
Authors: Martinez-Carillo Beatriz Elina , Valdés-Ramos Roxana , Guadarrama Ana Laura , Kormanovski Alexandre
Published: June 2021

It is currently known that there is a strong relation between diet, the immune system and the production of oxidative stress, but the area where they interact is very broad and diverse. The aim of this study was to determine the relation between the intake of a high fat diet and moderate physical exercise on the production of oxidative stress in young Balb/c mice. Animals were divided into control diet (CD) and high fat diet (HFD) (35% above normal) groups, starting at 21 days of age, during 9 weeks they were put to swim for 30 minutes 5 days a week. Peripheral blood was obtained and lymphocytes were purified for CD3+ and CD19+ determination by flow cytometry. Serum was used for analysis of Carbonylated proteins (CP), TBARS and Catalase (CAT). The CD group showed the following data: CD3+ 58.40% (±1.42), CD19+ 26.49% (±2.98); CP 9.66 mg (±1.25), TBARS 26.81 (±7.28), CAT 45.498.66 (±14 145); the HFD group: CD3+ 55.17% (±1.58), CD19+ 19.07% (±3.72); CP 4.31mg (±0.341), TBARS 14.92 (±6.51), CAT 20,419 (±1300). When comparing the groups, T‐lymphocytes and CP showed no differences, whereas B‐lymphocytes (t=3.39, p<0.001), CAT (t=8.64, p<0.001) y TBARS (t=5.96, p<0.015) were significantly decreased in the HFD group. All indicators showed a decrease with fat intake, apparently indicating that exercise is sufficient to overcome the dietary negative effect.
The Experimental Therapy of Brain Injury by Tissue Engineering with Hyaluronic Acid Based Scaffold
Authors: Qunyuan Xu , Ying Wang , Shaoping Hou , Weiming Tian , Fuzhai Cui
Published: June 2021

Stroke causes death and severe disability highly and often result in cavity formation in the brain. The complexity of the CNS makes efforts to repair injuries very difficult. Tissue engineering in combination with stem cell transplantation has the potential to fill such a cavity and replace lost neurons. In our study, a three dimensional hyaluronic acid (HA) based hydrogel was created as a biodegradable tissue engineering scaffold to mimic the structure and components of the extracellular matrix (ECM) in the brain. The molecules of poly‐L‐lysine (PLL) were immobilized on the backbone of the hydrogel for improving cell adherence and compatibility with brain tissue. In addition, a pH sensitivity antibody releasing system was developed by covalently attaching the antibody of Nogo receptor (Ab‐NgR) to the hyaluronic acid (HA) hydrogel, delivering the antibody to the injured brain, which can bind to multiple inhibitory myelin proteins, such as Nogo‐66, and promote neural regeneration. The modified hydrogel would be suitable for the acidosis in the brain tissue after injury. The antibody delivery system or the modified hydrogel was shown to have strong action to induce the growth of axons from the dorsal root ganglia in vitro, in addition to helping the cell adherence and survival. After implanting to the adult rat model of ischemia with occlusion of the middle cerebral artery, this antibody delivery system showed to have promotion function with regard to regeneration of neural cells in the host brain and improvement of behavior in those ischemic models. After implantation of this polymer hydrogel into the injured area of the brain of rat models, it was clearly shown that the hydrogel had good compatibility with the brain tissue and inhibitory action for genesis of glial scar. Also, the hydrogel could correctly bridge the tissue defects and form a permissive interface with the host tissue to favour axonal ingrowth and angiogenesis. The HA hydrogel scaffolds modified by ab‐NgR and PLL are therefore appealing for cell delivery and tissue development in the brain following stroke.

The work was supported by the National Natural Science Foundation of China (Grant Nos. 30700210, 30670656, 30570578), the National Basic Research Program of China (Grant No. 2007CB947704), and the Beijing Committee of Science and Technology (No. Z0005187040311).
Didox‐A Multipotent Drug for Treating Demyelinating disease
Authors: DeVries George Henry , Farrer Robert , Papadopoulos Catherine , Campbell Christian , Litz Julie , Paletta Janice , Dupree Jeffrey , Elford Howard
Published: June 2021

Chronic experimental allergic encephalomyelitis (EAE) is an animal model for multiple sclerosis the most common demyelinating disease. Didox is a polyhydroxyphenol which can inhibit biological activities important for the progression of EAE. After induction of chronic EAE, didox was given daily to C57Bl/6 mice either by intraperitoneal injection (275 mg/kg) or by oral gavage (550 mg/kg in carboxymethylcellulose); mice were evaluated daily for clinical severity (stage 4=maximum severity). Didox given prior to the onset of disease, delayed the onset and reduced the severity of disease. Didox given at the peak of disease completed reversed clinical symptoms. Didox given one week after peak disease reduced clinical symptoms from 4 to 2. In a dose dependent manner didox inhibited peripheral T‐cell proliferation, secretion of both IFN‐gamma and Il‐17a by activated T‐cells and secretion of nitrite by microglia. Morphological examination of the CNS of didox‐treated mice which had reversed from stage 4 to stage 0 revealed preservation of axons and myelin similar to what was observed in the CNS of mice when they initially reached stage 4. EM analysis of didox treated animals revealed lymphocytes trapped in the perivascular space. The pleotrophic effects of didox make it an ideal candidate for demyelinating disease therapy. (Supported by the Dept. Veterans Affairs and Molecules for Health, Richmond, VA.)
IP3 receptor processing by the ERAD pathway
Authors: Wojcikiewicz Richard JH
Published: June 2021

Inositol 1,4,5‐trisphosphate (IP3) receptors are large ER membrane proteins which form tetrameric channels that govern the release of Ca2+ stored within the ER lumen of vertebrate cells. They are named for their ability to bind to and be opened by the second messenger IP3, which is generated at the plasma membrane in response to cell surface receptor activation. Thus, IP3 receptors are pivotal in signaling pathways that couple extracellular hormones, neurotransmitters and growth factors to increases in cytoplasmic Ca2+ concentration and the regulation of Ca2+‐dependent events (e.g. secretion, fertilization, apoptosis and gene expression). Surprisingly, when IP3 receptors are activated they are rapidly destroyed via the ER‐associated degradation (ERAD) pathway, a ubiquitination‐and proteasome‐dependent mechanism that clears the ER of aberrant proteins. I will review recent studies aimed at identifying which ERAD pathway components mediate IP3 receptor ERAD, focusing on a novel complex composed of the ER membrane proteins erlin 1 and 2 which binds to IP3 receptors immediately after they are activated, and the E3 ligase RNF170, which participates in IP3 receptor ubiquitination.
Effect of breakfast cereals with varying doses of oat fiber on appetite and satiety
Authors: Rebello Candida Joan , Johnson William D , O'Shea Marianne , Kurilich Anne , Greenway Frank L
Published: June 2021

Objective

To compare the satiety impact of Quaker Oatmeal and Quaker Oatmeal Squares with Honey Nut Cheerios.

Methods

96 healthy individuals, ≥18 years were enrolled in a randomized controlled crossover trial. Half the participants were given Quaker Oatmeal (QO) {6.7g fiber or Honey Nut Cheerios (HN) {4.5g fiber)}, and half received Quaker Oatmeal Squares (OS) {6g fiber} or HN. All breakfasts contained 355kcals (250kcals cereal and 105kcals milk). Visual analogue scales of hunger and satiety were completed at baseline, 30, 60, 120, 180 and 240 minutes. Subjects repeated the breakfast test at least a week later. Responses were analyzed as area under the curve (AUC) and significant differences from baseline.

Results

The AUC for fullness (p=0.005) and stomach fullness (p=0.0073) was greater with QO than HN. Hunger (p=0.0009), desire to eat (p=0.0002), and prospective intake (p=0.0012) decreased with QO as compared with HN. In a comparison between OS and HN greater fullness (p=0.0133) and stomach fullness (p=0.0245) was observed with OS at 240 minutes.

Conclusions

QO suppressed appetite and increased satiety when compared with HN. OS provided greater fullness than HN, at the final time point. The content of oat fiber and the vehicle of delivery are important components affecting the satiety process.

Study was funded by PepsiCo
Iron Absorption in Peruvian Breast‐fed Infants at Two and Five Months of Age
Authors: Finkelstein Julia L. , OˈBrien Kimberly O. , Abrams Steven A. , Zaveleta Nelly
Published: June 2021

The effects of maternal prenatal iron (Fe) supplementation on early Fe homeostasis in breast‐fed infants remains largely unexplored. Towards this aim, longitudinal Fe absorption (58Fe) studies were conducted in 41 breast‐fed Peruvian infants at 2 months and 5 months of age. Hodges‐Lehmann 95% CIs were used to express the effect size of Fe supplementation on differences between groups. Predictors of Fe absorption and changes over time were examined using multiple linear regression. Fe absorption from breast milk averaged 7.9% (SD: 9.5) and 12.6% (SD: 11.9) at 2 and 5 months of age. Infants born to Fe supplemented women had greater length at 2 months (p=0.01). Infants born to non‐Fe supplemented women had higher increases in hemoglobin (p<0.05) and Fe absorption (p<0.01), between two and five months of age. Maternal serum zinc and TIBC and infant sTfr levels were associated with significantly increased Fe absorption at 5 months (p<0.05). In analyses of changes in Fe absorption, infant hematocrit (p=0.01) and change in serum Fe (p=0.03) were significant predictors. Fe absorption in early infancy was associated with infant sTfr, hematocrit, and serum iron, and inversely associated with maternal Fe supplementation during pregnancy. Funded by The Nestle Foundation.
Docosahexaenoic acid alters cell death, cancer and cell‐cycle signaling networks in breast cancer cell lines
Authors: Field Catherine J , Ewaschuk Julia B , Nelson Randy , Newell Marnie , Jacobs Rene
Published: June 2021

Long‐chain n‐3 polyunsaturated fatty acids reduce viability of breast cancer cells. While the products of several genes are altered, the changes in gene expression responsible for these antitumor effects have not been clearly established. The objective of this study was to measure alterations in gene expression in breast cancer cells treated with docosahexaenoic (DHA) and eicosapentaneoic (EPA) acid. MDA‐MB‐231 (estrogen receptor, ER‐) and MCF‐7 (ER+) human breast cancer cells were treated with control media, 100 μM linoleic acid, DHA or EPA for 48 h. Gene expression was analyzed using Affymetrix GeneChip Human Gene ST 1.0 microarray chips and data analyzed using Partek Genomics Suite and Ingenuity Pathway Analysis. Principal Component Analysis revealed that treatment accounted for 40% of the alteration in gene expression in both cell lines. Compared to control, fatty acids changed networks of lipid metabolism and small molecule biochemistry (P<0.05). DHA altered cancer, cell death and tumor morphology cellular signaling networks, compared with other conditions, while EPA impacted an array of non‐cancer related networks (P<0.05). A number of previously unidentified genes were differentially expressed in response to DHA treatment. This study provides an understanding of the genomic changes induced by n‐3 PUFA in breast cancer cells. Funding from CIHR and JBE received a CIHR postdoctoral fellowship.
How often are others participating in infant‐feeding? An exploratory analysis of secondary objectives of the Baby‐Mine study
Authors: Bower Katherine M , Nicklas Jennifer C , Helvey Jennifer J , Sberna Angela N , Burney Janie L , Greer Betty P , Kavanagh Katherine F
Published: June 2021

Desire to share the infant‐feeding task is commonly offered as reason for lack of breastfeeding initiation, duration and/or exclusivity. Describing who is primarily responsible for preparation of infant formula was a secondary objective of a larger, longitudinal study assessing impact of bottle contents on rate of infant weight gain. Mothers of healthy, term, formula‐fed infants (< 3 months), were recruited via fliers, web ads, and a birth registry. At two time points, mothers recorded infant intake for 48 hours, including who prepared each bottle. Preliminary analysis of 31 mothers with complete data at both time point 1 (TP1: infants ~ 2.4 mo) and time point 2 (TP2: infants ~4.1 mo) indicate that, though others (e.g., fathers, extended family members, and childcare personnel) were involved with preparation, mothers remained primarily responsible for this preparation. Mothers prepared 87.4% of bottles at TP1, increasing to 89.7% at TP2, with father involvement in preparation declining over time, from 8% (TP1) to 5.7% (TP2). This preliminary analysis triggered the addition, to the TP2 interview, of exploratory, open‐ended questions regarding expectations of infant‐feeding support (both prior to and after birth). Results of this qualitative exploration will be presented and contrasted with actual infant‐feeding support, possibly suggesting future areas of inquiry among formula‐feeding mothers.

Grant Funding Source: USDA/NIFA/AFRI Award‐2010‐85215‐20663
Clinical Application of Measurement of Breastmilk
Authors: Kent Jacqueline Coral , Langton Diana , Hepworth Anna , Hartmann Peter
Published: June 2021

We aimed to assess whether measurement of 24‐h milk production (MP) affects breastfeeding (BF) confidence, which may in turn affect BF exclusivity and duration.

Mothers (n=105) reported their BF confidence and perception of milk supply before and after measuring MP by test‐weighing (BabyWeigh scales, Medela AG) and being advised of the normal range of MP (478–1298g). A second measurement of MP was done 3.7 ± 2.9 weeks later in a self‐selected sub‐group (n=19, MP 237–863g) after advice from a lactation consultant.

Of 76 mothers initially confident in their BF, only 4 lost confidence, and these 4 had MP<700g. Of 29 mothers initially not confident in their BF, 18 gained confidence. Of the 11 still not confident, 6 had MP<700g. BF confidence was not related to actual MP either before (P=0.787) or after (P=0.236) measurement of MP.

Mothers who initially perceived that their milk supply was normal gained confidence in their BF after measurement (P=0.009). Mothers who perceived that their milk supply was low had no change in BF confidence before and after measurement (P=0.658).

Mothers who repeated measurement of MP showed an increase of 154±128g (P=0.013). The majority (n=11) remained confident throughout, and 7 gained confidence.

We conclude that BF confidence is improved by measuring MP when MP is >700g. Moreover, measurement can quantitate improvement in MP.

Research support was an unrestriced grant from Medela AG.
ReishiMax improves antioxidant capacity in an oxidative stress model and extends lifespan in a natural aging model
Authors: Yang Jieying , Wu Zimei , Yao Yisang , Zhang Yan , Zhao Chunsheng , Dong Yunzi , Tan Ningzhi , Zhu Jia-Shi
Published: June 2021

We reported that ReishiMax (RM, a Ganoderma lucidum extract) improved immune functions and inhibited cancer malignancy. We further studied its effect on antioxidant and lifespan extension in mice. (1)Antioxidant study: 2‐mo male mice were randomized to receive 60 days of vehicle or RM at a dose of 175, 350 or 700 mg/kg, and given a dose of 11 Gy 60Co on Day 60 and sacrificed on Day 64. Compared to radiation controls, 60 days of RM increased plasma GSH by 34–42% (p<0.05) and liver CAT by 19–30% (p<0.01) in the 3 dose groups. RM increased liver GSH‐Rd by 9% (p=0.03, 175 and 350 mg/kg), liver GSH‐Px by 10% and plasma thiol groups by 12% (p<0.01, 700m/kg). (2)Lifespan study: Male and female ICR mice (12‐mo) were randomized to receive vehicle or RM at a dose of 175, 350 or 700 mg/kg prior mixed with forage. Calorie intake was adjusted twice a week to match the levels for controls. Compared to controls, the median lifespan was extended with RM by 35–69 days, lifespan of the longest surviving mice by 186–262 days, and the maximal lifespan (average of the longest 10% lifespan) by 124–191days (p<0.05). Kaplan‐Meier Survivor analysis showed significantly extended lifespan and reduced death risks with RM, with the best survivor curve observed in mice at RM 175 mg/kg (p=0.02). In conclusion, RM extends lifespan in natural aging mice and improves antioxidant capacity in oxidative stress mice, supporting in general the anti‐aging activity of RM.
A double‐blind, randomized, controlled clinical study to evaluate the properties of Saccharomyces cerevisiae CNCM I‐ 3856 on Irritable Bowel Syndrome management
Authors: Desreumaux Pierre , Housez Béatrice , Cazaubiel Murielle , Pelerin Fanny , Jüsten Peter
Published: June 2021

Probiotics show beneficial properties in the management of Irritable Bowel Syndrome (IBS). Saccharomyces cerevisiae CNCM I‐3856 already demonstrated interesting properties in preclinical models. This double‐blind, randomized, controlled clinical study evaluated the properties of Saccharomyces cerevisiae CNCM I‐3856 to decrease the abdominal pain/discomfort in subjects suffering from IBS. Subjects with IBS (ROME III criteria) were recruited and consumed either the strain (n=100) or a placebo (n=100) for 8 weeks. IBS symptoms and stool frequencies and consistencies were evaluated daily, and the improvement in abdominal pain/discomfort weekly. IBS symptoms (abdominal pain/discomfort, bloating and flatulence, straining) significantly improved in both groups during the study, with no statistical difference between the 2 groups. Improvement in abdominal pain/discomfort after 4 weeks of treatment was significantly better in the active group (62.8% of subjects with improvement) than in the placebo group (47.3%) (p<0.05). No intergroup difference was observed on the other criteria. As expected, placebo effect is an important factor when considering IBS, and this may explain the weak differences between S.c CNCM I‐3856 and the placebo. The significant improvement of abdominal pain reported by subjects after 4 weeks of S.c CNCMI‐ 3856 supplementation is of clinical relevance for subjects and clinicians.
Association between oral health and nutrient intake in twelve‐year old Puerto Rican children
Authors: Palacios Cristina , Torres Roxana , Santos Elvia , Rivas-Tumanyan Sona , Orraca Luis , Elias Augusto
Published: June 2021

OBJECTIVE

To evaluate the association between oral health and nutrient intake in 12 year‐old Puerto Ricans.

METHODS

An islandwide study in 1550 children was conducted in 2010–11 using a probabilistic sample. NIDCR diagnostic criteria were used for DMFT assessment. Exams were conducted by 3 calibrated examiners; 24‐h diet recall interview were performed in a subset and analyzed with NDSR. Subjects were grouped according to DMFT, number of decayed (DT) and missing teeth (MT) using the cut‐off point of 1 for each index (≥1 vs. 0). Differences between groups were evaluated with Wilcoxon test.

RESULTS

Preliminary results in 338 children show a median DMFT of 2.0; 65% had DMFT ≥1; 36% had DT ≥1 and 3% had MT ≥1. Children with a DMFT of ≥1 compared to those with 0 had higher intake of CHO (213 vs. 197 g), sucrose (39 vs. 28 g), total sugars (104 vs. 93 g) and fruit juice (1.3 vs. 0.9 servings) (p<0.05). Compared with children without any decayed teeth, those with at least 1 decayed tooth had higher intake of calories (1670 vs. 1570 kcals), sugars (109 vs. 96 g), fruit juice (1.6 vs. 1 serving), and refined foods (4.5 vs. 4.2 servings) (p<0.05). Those with a MT score of ≥1 compared with 0 had higher intake of calories (2269 vs. 1619 kcals), CHO (312 vs. 204 g), sugars (177 vs. 98 g), and added sugars (105 vs. 68 g) (p<0.05).

CONCLUSION

Carbohydrate quality intake was associated with the oral health status in Puerto Rican children.
Food Dignity: five community food system stories
Authors: Porter Christine M. , Daftary Sarita , Herrera Hank , Sequeira E. Jemila , Sutter Virginia
Published: June 2021

Many communities are tackling hunger, obesity, equity and other issues by expanding local engagement with and control of food systems. This paper examines the practice and potential of community‐driven approaches to food security through five case studies of community food system projects located in California, Wyoming and New York. The project coordinators are coauthors of this paper and team members of the Food Dignity action, research and education project (www.fooddignity.org). Research methods include interviews and narrative inquiry analysis, participation and observation, file coding, and Photovoice. Each project is working to build local control over and engagement with the food system. The actions, challenges, strategies and successes of these initiatives will be highlighted. We close with implications for the supportive roles nutrition professionals should play. Funding from USDA/NIFA/AFRI Competitive Grant no. 2011‐68004‐30074.
Who is Cooking? US patterns and trends on food preparation and consumption of home‐cooked food between 1965 and 2008
Authors: Smith Lindsey Patricia , Ng Shu Wen , Slining Meghan M , Popkin Barry M
Published: June 2021

Little research has been done on cooking trends and their effects on US diets. One 24‐hr diet recall from nationally representative surveys in 1965, 1977–78, 1989–91, 1994–96, and 2003–2008 was used to examine daily energy intake by food source (home v. away) among individuals >2 years. Nationally representative time use data from the American Heritage Time Use Study {surveys in 1965, 1975, 1985, 1992, 1994, and 2003 (updated soon with 2010)} was used to examine trends on time spent preparing food and meal‐related cleaning among individuals aged 18–64 years. T‐tests were conducted to compare if differences over time were significant. The proportion of kcal/d consumed from the home food supply fell from 92.4% in 1965 to 69.1% in 2007 in children and adults (p <0.01). Among adults, cooking time decreased from 4.7 hr/wk in 1965 to 2.9 hr/wk in 2003 (p <0.01) while time spent cleaning decreased from 2.3 hr/wk to <1 hr/wk (p <0.01). The proportion of adults who engaged in any cooking activity on a given day decreased from 59% in 1965 to 51% in 2003 (p <0.01), while the proportion of adults who participated in cleaning fell from 47% to 22% in the same period (p <0.01). Important differences by gender, age‐group, race‐ethnic status and education are presented. We explore the healthfulness of these trends by presenting the sources of calories, sugar intake and saturated fat intake over time.

Grant Funding Source: Robert Wood Johnson Foundation (68793) and the National Institutes of Health (R01 HL104580 and CPC 5R24HD050924)
In situ quantification of macrophage AIM2 inflammasome activation during Francisella tularensis infection by fluorescence proximity ligation
Authors: DeLoid Glen , Kobzik Lester
Published: June 2021

The AIM2 inflammasome is activated in cells infected with Francisella tularensis (FT), and required for clearance of FT in mice. Existing assays of inflammasome activation include measurement of caspase‐1 activity or co‐precipitation of inflammasome proteins in cell lysates, but do not provide quantification or localization of specific inflammasomes within individual cells. We developed a fluorescence proximity ligation method for in situ detection of AIM2 inflammasome assembly within intact cells. Antibodies conjugated to specific oligonucleotides bind to self‐associated AIM2 proteins; their proximity allows the creation of a DNA scaffold that is then decorated with complementary fluorescent oligonucleotides. We tested the method in macrophages infected with FT using both high‐throughput fluorescence microscopy and flow cytometry. Marked increases in AIM2 assembly were observed by both microscopy and FACS analysis following FT infection, consistent with FT‐mediated AIM2 assembly previously reported in the literature, and also corroborated by IL1‐β ELISA. This method is being extended to additional inflammasome types and has potentially broad utility, including use in genomic and small molecule screens.

Supported by NIH/NIEHS 5P30ES00002‐48
Influence of excess postexercise leucine ingestion on mTORC1 signaling and gene expression in skeletal muscle of older men: a 24 hr time‐course
Authors: Dickinson Jared M , Gundermann David M , Walker Dillon K , Reidy Paul T , Drummond Micah J , Arora Mohit , Volpi Elena , Rasmussen Blake B
Published: June 2021

Essential amino acid (EAA) ingestion enhances postexercise muscle protein synthesis, and in particular leucine is thought to promote a greater stimulatory effect. The purpose of this preliminary study was to determine the effect of ingesting excess leucine following resistance exercise (RE) on skeletal muscle signaling and gene expression in older adults over a 24h time‐course. Older men performed a bout of RE and at 1h postexercise ingested 10g of EAA containing either a leucine content similar to high quality protein (CTRL, 1.8g leucine) or excess leucine (LEU, 3.5g leucine). Muscle biopsies (vastus lateralis) were obtained at basal and at 2, 5 and 24h postexercise for examination of mTORC1 signaling (western blot) and expression levels of genes (qPCR) involved with muscle growth (MyoD) and atrophy (MuRF‐1), amino acid transport (LAT1/SLC7A5, SNAT2/SLC38A2), and mitochondrial biogenesis (PGC‐1α). Both groups experienced similar increases in mTORC1 signaling and gene expression at 2 and 5h postexercise, which were more pronounced at 2h. However, at 24h postexercise LEU appeared to maintain higher expression levels of MyoD and amino acid transporters. These preliminary data suggest that excess leucine ingestion following RE may prolong the anabolic response and sensitivity to amino acids in skeletal muscle of older adults.

NIAMS R01AR049877, NIA P30AG024832, NIH T32HD07539, NCRR 1UL1RR029876
Buccal Swab IL‐1ra in Necrotizing Enterocolitis: A Predictive Biomarker
Authors: Torrazza Roberto Murgas , Li Nan , Mai Volker , Chen Sixue , Chow Marjorie , Kim Ee-Kyung , Neu Josef
Published: June 2021

Background

Necrotizing Enterocolitis (NEC) is a major cause of death and morbidity in very low birth weight (VLBW) infants. IL‐1ra is the competitive receptor antagonist for IL‐1 a cytokine that promotes inflammation and causes an increase in intestinal epithelial tight junction permeability.

Hypothesis

Buccal sample proteomic analysis will provide biomarker proteins for NEC prediction.

Method

buccal swab samples one, two and three weeks prior to the development of NEC of 3 NEC and 3 matched controls (n=6) <32 wk gestational age and <1250g were subjected to 2D‐DIGE and LC‐MS/MS analysis. After identification of 37 altered proteins we chose 3 candidate proteins using a broad systems biologic analysis approach. Western blot analysis showed lower IL‐1ra in patients with NEC.

Results

IL‐1ra was decreased in VLBW infants with NEC compared to controls (p <0.01).

Conclusions

our results suggest that IL‐1ra could be a predictive biomarker for NEC.

Grant Funding Source : NIH RO1 HD 059143
When evolution hurts: height, arthritis risk, and the regulatory architecture of GDF5 function
Authors: Capellini Terence Dante , Chen Hao , Kingsley David
Published: June 2021

The Growth and Differentiation Factor 5 (GDF5) gene controls both epiphyseal chondrocyte maturation and synovial joint formation. Recent studies have shown that high frequency genetic variants in GDF5 are significantly associated with stature and osteoarthritis risk in human populations. Although these associations have been highly replicated, the causal base pairs controlling height and arthritis risk are still unknown. Here we use studies in transgenic and knockout mice to identify the regulatory regions controlling normal GDF5 expression and function. Scanning studies with large Bacterial Artificial Chromosome clones shows that key GDF5 regulatory sequences are located over a large physical interval both 5 and 3 prime of the gene. Multiple enhancers map within these regions, each controlling expression in separate skeletal structures, including limb growth plates or individual synovial joints. Several of these enhancers map in the genetic interval that is strongly associated with both height and arthritis risk in humans. Molecular signatures suggest that a variant regulatory block at the GDF5 locus has been the target of strong natural selection during recent human evolution, particularly in out‐of‐Africa populations. Past selection at the locus has driven some human regulatory variants to very high frequency, with important consequences for the overall risk of arthritis in modern populations.

Grant Funding Source: national institute of health
The Function of Ocular Lens Intermediate Filaments in Normal and Pathogenic Biology
Authors: FitzGerald Paul , Hess John F , Yoon Kyoung-hye
Published: June 2021

The ocular lens sequentially expresses two different classes of Intermediate Filament (IF) proteins in the course of terminal differentiation. The less differentiated lens epithelial cells express the common IF protein vimentin. However, as lens cells enter into terminal differentiation they expresses two lens‐specific IF proteins, CP49 and filensin. These two IF proteins are unique among IF proteins in that they are found not in canonical 8–11 nm IFs, but in a structure termed the Beaded Filament (BF). To assign function to the Beaded Filament (BF), we used a knockout approach to delete both CP49 and filensin. The data suggest that the Beaded Filament is not required for the remarkable structural differentiation of either lens fiber cells, or the lens as a tissue. However, the BF is required to maintain these structural phenotypes with age. The knock‐in mouse suggests that the human disease‐causing mutation identified in CP49 results in a loss‐of‐function phenotype due to the absence of BF, compounded by a “gain‐of‐toxic function phenotype: the mutation in CP49 prevents the efficient removal of CP49, resulting in accumulation of protein aggregates.
A knotty problem: Dissecting the molecular mechanics of mRNA recruitment to the eukaryotic ribosome
Authors: Lorsch Jon R.
Published: June 2021

Using a fully reconstituted S. cerevisiae translation initiation system, we are dissecting the molecular mechanics of mRNA recruitment to the 43S pre‐initiation complex (PIC). Efficient recruitment of capped mRNAs requires eIF3 and the eIF4 factors, which stabilize binding of the message and dramatically increase the rate of recruitment. Uncapped mRNAs can be recruited through an alternative pathway that does not require the eIF4 factors. This pathway yields a complex that is unable to effectively locate the start codon. The cap strongly inhibits this alternative mRNA recruitment pathway, imposing a requirement for the eIF4 factors for rapid and stable binding of mRNA to the PIC. Our data suggest that the 5′‐cap serves as both a positive and negative element in mRNA recruitment, promoting initiation in the presence of the full set of mRNA handling factors while preventing binding to the ribosome via an alternative, aberrant pathway requiring only eIF3. Thus the cap ensures that only fully functional pre‐initiation complexes containing all the required factors are assembled on an mRNA.
Mechanism of action of miRNA
Authors: Fabian Marc R. , Sonenberg Nahum
Published: June 2021

MicroRNAs (miRNAs) inhibit mRNA expression in general by base pairing to the 3′UTR of target mRNAs and consequently inhibiting translation and/or initiating poly(A) tail deadenylation and mRNA destabilization. We established a mouse Krebs‐2 ascites extract that faithfully recapitulates the miRNA action in cells (Mathonnet et al., 2007). We demonstrated that the let‐7 miRNA inhibits translation of reporter mRNA at the initiation step. Translation inhibition is subsequently consolidated by let‐7‐mediated deadenylation, which requires both the poly(A) binding protein (PABP) and the CAF1 deadenylase, which interact with the let‐7 miRNA‐loaded RNA‐induced silencing complex (miRISC) (Fabian et al., 2009). Importantly, we demonstrated that GW182, a core component of the miRISC, directly interacts with PABP via its C‐terminus and that this interaction enhances miRNA‐mediated deadenylation (Fabian et al., 2009; Jinek et al., 2010). The miRISC binds the deadenylation machinery directly and independently of PABP. We are now studying how the miRISC recruits the deadenylation machinery in a PABP‐independent manner, and how these interactions impact both deadenylation‐dependent and – independent translational repression.
Phenotypic screening in complex cellular extracts to identify novel antimitotic targets and compounds
Authors: King Randall , Zeng Xing , Sigoillot Frederic , Gaur Shantanu , Choi Sungwoon , Cuny Gregory
Published: June 2021

Conventional approaches to drug screening involve identification of a drug target and development of an assay with purified components. In contrast, phenotypic screens in intact cells can identify compounds that act through unique mechanisms, but identifying the targets of active compounds can be challenging. Here I describe our efforts to perform high throughput small molecule screens in complex cellular extracts. This approach harnesses the complexity of cellular systems, yet provides focus that facilitates the process of target identification. We have made use of Xenopus cell cycle extracts to identify small molecules that block cell cycle progression through novel mechanisms. I will describe how these efforts led to the identification of the first small molecule inhibitor of the Anaphase‐Promoting Complex (APC), a ubiquitin ligase required for exit from mitosis. I will discuss why inhibitors of the APC may be more effective at inducing mitotic arrest and cell death than conventional antimitotics that target the mitotic spindle.
High Throughput Tandem‐Affinity Proteomics Builds Protein Interactomes to Explain Human Disease
Authors: Jackson Peter K
Published: June 2021

The accumulation of human genetic disease mutations underlies a need to understand protein networks altered in these diseases. We build high‐confidence protein‐protein interaction networks, using unbiased Tandem Affinity Purification‐mass spectrometry (AP‐MS). Using the gLAP Gateway recombination‐based vector system, and Flp‐recombinase enabled “Flip‐in” lines, we construct stable cell lines expressing GFP‐tagged, correctly localized proteins for AP/MS‐based protein identification. We tagged 12 human genetic disease proteins from Nephronophthisis (NPHP), Joubert (JBTS), and Meckel‐Gruber (MKS) syndromes. These autosomal recessive diseases have defects in the primary cilium, a hair‐like signaling structure on cells. These “ciliopathies” show cystic kidneys, retinal degeneration, and neural malformations. We mapped high confidence interacting networks with NPHP/JBTS/MKS proteins and discovered 800 proteins in connected protein modules that function (1) at the ciliary base; (2) at centrosomes; (3) in the pericentriolar material; and (4) around the ciliary axoneme, suggesting how proteins are trafficked in cilia. Using these interactors as candidates, linkage and sequencing analysis of 250 patients identified new ciliopathy disease genes: PDE6D, SCDDAG8, Ataxin 10 and Tectonic 2. A Tectonic 2 knockout mouse shows a similar neural phenotype. Our study illustrates the power of linking proteomic networks and human genetics to uncover critical disease pathways.
Mapping endocannabinoid signaling networks in the mammalian brain
Authors: Cravatt Benjamin F
Published: June 2021

Endogenous cannabinoids (endocannabinoids) are an important class of signaling lipids that act on both central and peripheral cannabinoid receptors, which also mediate the effects of delta9‐tetrahydrocannabinol, the active component of marijuana. The magnitude and duration of endocannabinoid signaling are tightly controlled in vivo by the action of multiple biosynthetic and degradative enzymes. Here, I will discuss our lab's efforts to develop selective genetic and pharmacological tools to perturb the function of individual endocannabinoid metabolic enzymes. These tools have not only confirmed key roles for enzymes, such as fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL), in endocannabinoid metabolism, but have also revealed unexpected connectivities between the endocannabinoid system and other lipid signaling pathways, including prostaglandins and lysophospholipids. Such ‘systems‐level’ interactions designate endocannabinoid hydrolases as regulators of larger metabolic networks that may influence diverse physiological and pathological processes, such as cancer, inflammation, and nervous system disorders.
Compensatory Evolution and Fixation of Rfampicin Resistance in MDR and XDR Tuberculosis
Authors: Barry Clifton Earl
Published: June 2021

Rifampicin resistance is a defining characteristic of the growing threat of multidrug resistant tuberculosis (MDR‐TB). Rifampicin resistance is mediated by mutation in the β–subunit of RNA polymerase, RpoB, and such mutation typically imparts a fitness deficit to the organism. Using whole genome sequencing of 50 drug‐susceptible and drug‐resistant clinical isolates we identified mutations that were present only the drug‐resistant strains. Within the RNA polymerase of drug‐resistant strains we found the expected mutations in the rifampicin‐binding region of RpoB associated with resistance, but we also found that such mutations often co‐occurred with others within other regions of RpoB, as well as mutations in the β‘‐subunit, RpoC. Here we show that these additional mutations restore wild type fitness to the organism and are therefore compensatory. Such compensated strains are fully fit, transmissible and often occur in clusters. Seven clinical isolates without apparent compensatory changes that displayed impaired fitness uniformly reverted to wild type RpoB alleles upon serial passage in culture without rifampicin and regained sensitivity to the drug. These results suggest that current treatment strategies that call for rechallenge of relapsed or failed patients with rifampicin containing regimens may result in permanent fixation of rifampicin resistance alleles in MDR‐TB strains.
Molecular dynamics of epigenetic transitions
Authors: Hager Gordon L
Published: June 2021

Eukaryotic transcription factors (TFs), regulate gene expression by interacting with chromatinized DNA response elements (REs). These interactions are strongly influenced by localized chromatin structures that modulate access of regulatory proteins to their recognition sites (epigenetics). Cell‐specific reorganization of these elements represents a major level of cell selective gene regulation. The underlying molecular mechanisms that govern the status of these elements are remarkably complex and dynamic [EMBO J 30:1459; Mol. Cell 43:145; EMBO J 30:3028; Cell 146:Aug 19, 2011]. Transcription factors require the assistance of multiple ATP‐dependent remodeling proteins to effect these reorganization events; numerous remodeling systems have now been characterized. We will discuss a general model for genome wide access to these regulatory elements.

This research was supported by the Intramural Research Program of the NIH, National Cancer Institute, Center for Cancer Research.
Strategies for Targeting Protein‐Protein Interactions in the Heat Shock Protein 70 (Hsp70) Complex
Authors: Gestwicki Jason Edward
Published: June 2021

Heat shock protein 70 (Hsp70) is a molecular chaperone that plays critical roles in protein folding and quality control. In these tasks, Hsp70 is assisted by co‐chaperones, including J proteins and nucleotide exchange factors, which associate with Hsp70 and help guide its activities. To better understand Hsp70's cellular roles, our strategy is to identify drug‐like small molecules that control the interactions between Hsp70 and its critical co‐chaperones. More specifically, we have been exploring a ‘gray box” strategy in which defined Hsp70 complexes are re‐constituted in vitro and their emergent activities are used to design chemical screening campaigns. Using this approach, we have screened >155,000 diverse compounds against a number of distinct Hsp70 complexes and identified candidates that interrupt protein‐protein interactions with co‐chaperones. We have shown that these compounds reduce the levels of some misfolded proteins, such as tau and huntingtin, in cell models. These results suggest that formation of specific Hsp70 complexes may control the fate of misfolded proteins in disease. Using these chemical probes and additional screening efforts, our long‐term goal is to understand how Hsp70's substrates are selected and how multi‐chaperone complexes guide triage decisions.
Exploring the Bacterial Terpenome
Authors: Cane David E
Published: June 2021

Tens of thousands of terpenoids are present in both terrestrial and marine plants as well as fungi. Terpenes are also produced by numerous bacteria, especially soil‐dwelling Gram‐positive organisms such as Streptomyces and other Actinomycetes. The majority of cyclic terpenes from bacterial species have been uncovered by the newly developed techniques of genome mining. The low level of overall sequence similarity among terpene synthases, however, has so far precluded any simple correlation of protein sequence with the structure of the cyclized terpene product. The actual biochemical function of a cryptic terpene synthase must therefore be determined by direct in vivo or in vitro experiments. The coordinated application of genome mining and biochemical characterization directly couples the discovery of natural products to the simultaneous identification of the responsible biosynthetic genes and enzymes.
Replacing laboratory animals by alternative material for teaching diabetes in practical classes
Authors: Rocha Maria Jose A , Tazinafo Lucas F , Basso Paulo J , Silva Mauro F
Published: June 2021

We developed alternative material for practical classes substituting laboratory animals to teach diabetes. For each group of students we used three small toy rats made of cloth. These had a ventral zipper that allowed stuffing with glass marbles to reach different weights. We then put the toy rats into metabolic cages with real food and water to simulate the real situation, and with recipients containing artificial urine simulating a sample collection after 24 hours. For each cage we had also prepared a recipient containing artificial blood consisting of a solution containing congo red, sodium fluoride, amide, and different amounts of anhydric glucose to simulate normal glycemia, hyperglycemia and very high hyperglycemia. The artificial urine contained acetone, yellow methanyl and anhydric glucose in different amounts so as to simulate two different levels of glycosuria. To simulate urine of a normal rat this was prepared without adding glucose. An ACCUCHECK Advantage (ACCU‐CHECK) system was used to measure glycemia levels. Ketonuria levels were analyzed by means of the uricolor bioassay.

The students were asked to enter the following values into a table, weight of the animal, amount of the urine and food collected, glycemia level, and presence or absence of ketonuria. Based on these data the students were asked to discuss the different types of diabetes.
Simulation activities increase medical student question performance compared to paper clinical case conferences
Authors: Harris David M , Laudadio Rachel , Campos Diego , Ryan Kathleen
Published: June 2021

The use and effectiveness of high fidelity patient simulators (PS) in preclinical medical education has not been as well studied as during the clinical years. The goal of this study was to determine whether a simulation activity (SIM) would enhance learning of cardiovascular function curves and acid base physiology better than a paper, clinical case conference (Con). Both the SIM and Con focused on the same clinical cases (heart failure in the CV module and COPD in the pulmonary module).

Methods

The Year 1 medical student class (n=192) was divided approximately into two halves with half doing a Con (group A) and the other half doing a SIM during the CV module (group B). During the pulmonary module group A did the SIM while group B did the Con. Switching of the groups allowed student participation in both modes of learning and served as a control. Student learning was assessed by performance on a quiz/exam question pertaining to the modules. We also asked a survey question to assess student perception of learning.

Results

A higher % of students in the SIM groups got the correct answer on both the cardiac module quiz (64.6% vs. 56.0%) and on the pulmonary module exam (77.6% vs. 72.3%) than students participating in the Con. Despite the higher % of students getting the answer correct following the SIM, student perception was that they had not learned the material as well in the SIM center. The only outstanding exception was that they felt that the SIM helped them to realize the importance of teamwork more than the Con.

Conclusion

These data suggest that SIM activities may facilitate student understanding of CV function curves and acid base physiology better than a paper, clinical case Con. Additionally, SIM activities may be an avenue to develop team building skills in the preclinical years.