bluuebunny/crossref_metadata_2025 huggingface dataset:
Computational imaging of heart morphogenesis in vivo
Authors: Rongish Brenda J , Cui Cheng , Lansford Rusty D , Little Charles D
Published: June 2021

Cardiac progenitor cells were followed in time and space from HH Stage 4 through Stage 12 in avian embryos to determine their position fate. Embryos were electroporated at HH Stages 3‐3+ with H2B‐GFP, a fluorescent nuclear marker, and subjected to wide‐field time‐lapse imaging. Thus, cardiac precursor cells were tracked from the primitive streak into the tubular heart, where their dorsal‐ventral and anterior‐posterior fates were determined. The data demonstrate the existence of a continuous heart field, expanding as a wide arc of progenitors at HH stage 4. Sub‐groups or anatomical bands of heart precursor cells change their relative positions as endoderm folding proceeds. Moreover, expression of the putative cardiac molecular markers, Nkx‐2.5 and Bmp‐2 does not fully overlap with a subset of cardiac precursors until HH Stage 10, the tubular heart stage. These data resolve the origin of cardiac progenitor cells and redefine the primary heart forming region in a warm‐blooded embryo. Supported by an AHA fellowship (CC) and the G. Harold and Leila Y. Mathers Charitable Foundation (CDL, BJR).
Characterizing the extracellular components of the hemopoietic stem cell niche
Authors: Nilsson Susie
Published: June 2021

Considerable evidence supports the proposal that hemopoietic localisation to marrow involves developmentally regulated adhesive interactions between hemopoietic stem cells (HSC) and the microenvironment. Our previous studies demonstrate that HSC reside within an endosteal stem cell niche, and identified several molecules that play critical roles in their attraction to, and retention and regulation within this region. We have described Hyaluronic acid (HA) as one of these molecules and shown that human and murine HSC synthesise and express HA. We demonstrated that HA is critical in the trans‐marrow migration, lodgement and regulation of HSC in their niche. Analysis of HAS−/− mice identify HA synthase 3 (HAS 3) as the main synthase mediating this component of HSC engraftment. In the absence of HAS‐3 synthase the endosteal region is devoid of HA, and the microenvironment is significantly impaired in its ability to attract and support HSC post‐transplant as well as regulate the HSC pool in vivo. Furthermore, transplanted HSC isolated from HAS‐3−/− mice have a reduced ability to lodge within the endosteal region and reconstitute hemopoiesis. In vitro, HA binding by a surrogate ligand has a negative regulatory effect of HSC proliferation and differentiation. Together these data suggest that HSC cell surface HA is critical in their lodgement and subsequent quiescence within the hemopoietic stem cell niche.
Be the apple of my eye: demonstrating the actions of the extraocular muscles.
Authors: Wineski Lawrence E.
Published: June 2021

Understanding the actions of the extraocular muscles, especially within the context of clinical testing of eye movements, often poses a challenge for beginning anatomy students. A simple demonstration of these muscle actions can greatly clarify the mechanical concepts in question. Required supplies include an apple (other select fruit will suffice), dissecting needle, several rubber bands, and several push pins. The stem of the apple represents the pupil, the dissecting needle serves as the axis of rotation of the eye, and the rubber bands (held in place with the push pins) represent the individual extraocular muscles. Pulling each rubber band causes the apple to turn about the dissecting needle in each of the three axes of rotation, allowing the user to test and visualize the muscle actions. This teaching tool is affordable and easy‐to‐master, thus allowing students to repeat the lesson at their leisure.
The mammalian genome as an RNA machine
Authors: Mattick John S , Croft Larry J , Pheasant Michael , Mercer Tim R , Dinger Marcel E
Published: June 2021

It appears that the genetic programming of the higher organisms has been fundamentally misunderstood for the past 50 years. It is now evident that the majority of the mammalian genome is transcribed, apparently in a developmentally regulated manner, and that most complex genetic phenomena in the higher organisms are RNA‐directed. Evidence will be presented (i) that regulation scales quadratically with function in integrated systems, including organisms, and that multicellular eukaryotes have solved this problem by the cooption of RNA as an analog‐digital regulatory system; (ii) that much, if not most, of the mammalian genome is not evolving neutrally, but is comprised of different types of sequences evolving at different rates under different structure‐function constraints; and (iii) that there are thousands of non‐protein‐coding transcripts in mammals that are dynamically expressed during differentiation, many of which show precise expression patterns and subcellular localization in different regions of the brain. These and other observations suggest that the majority of the mammalian genome is devoted to a hidden RNA regulatory system that directs developmental trajectories by controlling chromatin architecture and epigenetic memory, transcription, splicing, RNA modification and editing, mRNA translation and RNA stability.

(This work was supported by the Australian Research Council).
Single Molecule Studies Reveal the Mechanism and Energetics of Transcriptional Termination
Authors: Block Steven M , Larson Matthew H , Greenleaf William J , Landick Robert
Published: June 2021

Intrinsic transcription termination by bacterial RNA polymerase (RNAP) occurs at sequences coding for a G:C‐rich RNA hairpin followed by a 7–9 nt, U‐rich tract. We used single‐molecule optical trapping techniques to investigate the mechanism by which elements from three representative terminators (his, t500, tR2) destabilize the elongation complex (EC). For his and tR2 terminators, loads exerted to bias DNA translocation did not affect termination efficiency (TE). However, the force‐dependent kinetics of release at the t500 terminator and the force‐dependent TE of a mutant imply a forward translocation mechanism for this terminator. Tension applied to isolated U‐tracts induced transcript release in a manner consistent with shearing of the RNA:DNA hybrid. We deduce that different mechanisms of EC dissociation, involving hypertranslocation or RNA:DNA shearing, operate at terminators with different U‐tract sequences. Tension applied to RNA at full terminators suggests that closure of the final 2–3 hairpin bases supplies the energy that destabilizes the hybrid, and that competing nascent RNA structures modulate TE by slowing terminator hairpin formation. We propose a quantitative model based on energetics that successfully predicts the behavior for all three terminators and several mutant variants.
New Mechanisms for Old Targets: Novel Approaches to Steroid Receptors in Drug Discovery
Authors: Freedman Leonard P
Published: June 2021

Steroid hormones such as estrogens and androgens play critical roles in normal and patho‐physiology. Through their binding to nuclear hormone receptors, they also provide attractive targets for drug discovery. Considerable effort has been exerted over the past several years in designing so‐called selective estrogen or androgen receptor modulators that recapitulate the desired effects of these steroids on specific target tissues (i.e., the inhibition of bone resorption or stimulation of bone formation), without undesired effects on other target tissues. While much progress has clearly been achieved, recent insights into the mechanisms of action of these targets provide new opportunities to generate compounds and drugs with even greater efficacy and selectivity than those that are currently being used as established therapies. For example, the activation of particular non‐genomic signal transduction cascades has been suggested to play a key role in estrogen‐induced cardio‐, neuro‐, and osteo‐protection. Therefore, the development of functionally‐selective ER ligands may provide a novel means for preserving the beneficial effects of estrogens on nonreproductive tissues during post‐reproductive life, while minimizing or eliminating their action on reproductive tissues. The data that will be presented may lead to the development of a new generation of estrogens with superior pharmacological properties.
Regulation of RecA protein by other proteins
Authors: Cox Michael M
Published: June 2021

The RecA protein is subject to regulation by multiple other proteins in E. coli. These regulatory proteins affect the formation, stability, and function of RecA filaments. The RecFOR proteins are involved in the loading of RecA protein onto SSB‐coated ssDNA. RecOR is necessary and sufficient for this function under most conditions. However, the RecF protein plays varied roles in supplementing the function of RecOR. The RecX protein inhibits RecA protein, and also exhibits a varied palette of inhibitory mechanisms. RecX proteins from different bacteria exhibit the range of potential RecX inhibitory functions. The RecF protein antagonizes RecX function.
Mechanism of recombination in eukaryotes: Some remodeling required
Authors: Heyer Wolf‐Dietrich , Li Xuan
Published: June 2021

Homologous recombination is a high‐fidelity, template‐dependent pathway to repair complex DNA damage, including double‐stranded DNA breaks and interstrand crosslinks. Moreover, recombination supports DNA replication in the recovery of broken replication forks and the repair of gaps caused by fork stalling. Rad54 is a core component of eukaryotic recombination and supports the functions of Rad51, the eukaryotic homolog of the bacterial RecA protein. Rad54 is a dsDNA‐dependent motor protein of the Snf2 family and specifically dissociates Rad51 from dsDNA. Rad51 is bound to dsDNA either in dead‐end complexes or to the heteroduplex DNA in the D‐loop, the product of DNA strand exchange. Rad51 turnover from the heteroduplex DNA product is required to allow access of DNA polymerase to the invading 3′‐OH end. Rad54 not only stimulates DNA strand invasion by Rad51 but is also absolutely required for DNA polymerase to extend the invading strand. This control of the transition from a meta‐stable, nascent D‐loop to DNA repair synthesis possibly provides a time window to reverse illegitimate DNA strand invasions before they are extended and potentially lead to genome rearrangements.
Design of selective and multi‐specific protein‐protein interfaces
Authors: Kortemme Tanja
Published: June 2021

We develop and apply computational models towards the ultimate goal to delineate and quantitatively characterize sets of protein‐protein interactions controlling complex biological processes. This talk will focus on computational protein design approaches to modulate interactions formed by “hubs” in interaction networks and to “simplify” sets of interactions by engineering new protein pairs with altered specificity and reduced cross‐reactivity. I will also describe recent progress towards improving our protein design models in two respects, (1) to more accurately model changes in protein conformation in response to sequence perturbations predicted by design simulations, and (2), to optimize protein sequences for multiple fitness criteria, such as to adopt multiple conformations or to function within a network of proteins where correct interactions should be favored and unwanted interactions avoided. Combining a representation of proteins as conformational ensembles with sequence design shows encouraging results for predicting tolerated sequence space for a given fold or interaction, and makes testable predictions for altering patterns of interactions within sets of interaction proteins.
Metabolic Regulation of Chromatin Structure During Epilepsy: Therapeutic Implications.
Authors: Roopra Avtar S
Published: June 2021

Energy supply is critical for essential functions in all cells. There is increasing evidence that dietary carbohydrate and caloric restriction moderate cellular responses to damage, alter ageing processes, enhance longevity and may have therapeutic affects in neurological disorders such as epilepsy, Alzheimer's Disease and Huntington's Chorea. Dietary regimes termed ‘ketogenic diets’ which iso‐calorically replaces carbohydrates with fats and protein, can produce significant anticonvulsant effects in patients with epilepsy and have successfully been used therapeutically. The mechanisms behind the beneficial effects of ‘ketogenic diets’ are completely unknown. We show that neuronal genes heavily implicated in epileptogenesis are directly and chronically controlled by cellular metabolism due to regulated recruitment of a metabolism‐sensing chromatin modifying complex to their promoters in vivo. We propose that these mechanisms may underlie the beneficial effects of ‘ketogenic diets’ in epilepsy. Our model has allowed the prediction and validation of a small molecule regulator of energy metabolism to potently inhibit epileptogenesis in animal models with no detected adverse side effects.
Molecular Insight into Chemotactic Signaling
Authors: Parent Carole A
Published: June 2021

Dictyostelium, human leukocytes, as well as other types of cells possess the ability to polarize and move in a directed fashion in response to chemoattractants. In Dictyostleium the most potent chemoattractant is cAMP, which, like chemokines, transduces its effects by binding to G protein‐coupled receptors. The binding of cAMP to its receptor activates a plethora of responses, including the activation of the adenylyl cyclase ACA, which converts ATP to cAMP. ACA activation requires Gβγ‐subunits, the PH‐domain‐containing protein CRAC (Cytosolic Regulator of Adenylyl Cyclase), and the Target Of Rapamycin Complex 2. While part of the cAMP synthesized remains inside the cells to activate downstream effectors, the majority of cAMP is secreted to relay the chemoattractant signal to neighboring cells. We find that ACA is highly enriched at the back of cells and is essential for their ability to migrate in a head‐to‐tail fashion during chemotaxis. The asymmetric distribution of ACA is not dependent on the presence of PKA or CRAC. In addition, ACA remains enriched at the back of cells lacking either PAKa or myosin II, both of which localize at the cell posterior. However, the asymmetric distribution of ACA requires vesicular trafficking and involves intact actin and microtubule networks, as well as de novo protein synthesis. We propose that the asymmetric distribution of ACA provides a compartment from with cAMP is secreted to locally act as a chemoattractant and suggest that similar compartmentalization mechanisms exist in mammalian cells during embryogenesis, wound healing, neuron growth, and metastasis.
Lipid‐mediated ER stress
Authors: Schaffer Jean E
Published: June 2021

Cell dysfunction and cell death induced by lipid accumulation in non‐adipose tissues, or lipotoxicity, may contribute to the pathogenesis of diabetes and obesity. We have investigated this pathophysiological response in a cell culture model in which growth media is supplemented with excess palmitic acid. Biochemical studies reveal that palmitate is rapidly incorporated into endoplasmic reticulum membranes (ER), leading to membrane remodeling that results in a breach of ER structure and function. Palmitate also induces oxidative and ER stress. In complementary genetic studies in mammalian fibroblasts, we are beginning to identify genes critical for lipotoxic cell death. These findings are being translated into murine models of lipotoxicity in which lipid accumulation causes organ dysfunction. By combining in vitro identification of molecular targets and signaling pathways with in vivo models of lipotoxic disease, our goal is to provide insight into the pathogenesis of common metabolic diseases.
Engineering small molecules that nucleate assembly of protein complexes
Authors: Ansari Aseem Z.
Published: June 2021

Cooperative assembly permits weak interactions between components of the gene expression machinery to be harnessed together in the creation of a multicomponent complex of high affinity and exquisite specificity. In the context of transcription factors, weak molecular interactions between transcription factors facilitate the assembly of multiprotein complexes. These complexes present multiple activation modules thereby nucleating the assembly of the transcriptional machinery.

The modular nature of transcription factors lends itself to creation of ligands that utilize multivalent cooperative interactions to enhance binding affinity and specificity. We will present our design of synthetic Hox mimics that cooperatively stabilize the assembly of cellular transcription factor to a targeted DNA sequence. Our modular design can be broadly applied to engineer molecules that nucleate the assembly of other transcription factors. These molecules can then be used to modulate gene networks and thereby regulate cell fate.
A Universal Strategy for Virus Attenuation
Authors: Cameron Craig E
Published: June 2021

The rate‐limiting step for live‐virus vaccine development is the identification of a suitable attenuated virus. Isolation of attenuated viruses is a random, slow process that often involves passage of the virus in “foreign” or non‐permissive cell lines. The availability of a universal strategy for virus attenuation would remove this bottleneck in vaccine development, paving the way for rapid, effective response to viruses with regular intervals of antigenic shift, newly emerging and re‐emerging viruses, or agents of terror and biological weapons. We have discovered a novel method to attenuate any class of virus. A virus attenuated via our method is able to confer protection against a lethal challenge with the wild‐type virus.
Effect of three supplements with identical micronutrient content on length and weight of Mexican children
Authors: Neufeld Lynnette M , Dominguez Clara P , Guerra Armando Garcia , Feregrino Raquel Garcia , Cabrera Amira Hernandez
Published: June 2021

The objective of this analysis was to assess the impact of three nutritional supplements with identical micronutrient content on length and weight of children at 24 mo of age. Communities (18 per supplement) were randomly assigned to receive a fortified food (FF), syrup (SY) or Sprinkles (SK). Children 6 to 12 m of age, beneficiaries of the Oportunidades program were eligible to participate. Supplements were delivered daily (6 mo) then weekly. Measurements were taken at baseline and 24 m of age. Appropriate statistical analyses for cluster randomized trials were used. 927 children were assigned to treatment (FF n=265; SY n=323; SK n=339) and 80% completed the trial. There were no statistically significant differences between groups at baseline for mean height‐age Z (HAZ −1.0±1.0) weight‐height Z (WHZ 0.4±1.0) or prevalence of stunting (FF 14.7%; SY 18.5%; SK 19.3%, p>0.10). At 24 mo of age, there was no difference between groups in mean HAZ (FF −1.0±1.0; SY −1.2±1.0; SK −1.1±1.0, p>0.10), WHZ (FF 0.12±0.96; SY 0.08±1.10; SK 0.17±0.96, p>0.10) or the prevalence of stunting (FF 14.8%; SY 21.6%; SK 17.5%, p>0.10). There was no difference in the prevalence of stunting between baseline (17.7) and 24 mo (18.1) (p>0.10). This study had no true placebo and we do not know to what extent the supplements influenced growth. The lack of change in mean HAZ and the prevalence of stunting from baseline to follow‐up may suggest that the three supplements were equally efficacious to prevent further growth retardation.

The Oportunidades program financed this study and holds the rites to the data presented.
Copper deficient rats exhibit no alterations in plasma or brain NO metabolites, 3‐nitrotyrosine peptide abundance, or NOS mRNA expression
Authors: Prohaska Joseph R , Walters Mark
Published: June 2021

Others have reported that copper deficient (Cu−) rodents have alterations in nitric oxide (NO) biology including: higher nitric oxide synthase (NOS) activity and expression, and higher 3‐nitrotyrosine abundance (a marker of peroxynitrite production predicted to be higher because of higher NO and superoxide). Altered NO could impact brain development and metabolism. Holtzman rat dams were fed a Cu− diet and given either Cu supplemented (Cu+) or deionized water starting on gestation day 7. Cu− dams at weaning and their male pups at P26 had near zero plasma ceruloplasmin activity. Compared to Cu+ P26 male rats Cu− rats had heart/body weight values more than twice as high. However, plasma levels of NO metabolites (nitrite and nitrate) were not altered by Cu deficiency in dams or pups. Mean values in all groups were approximately 60 μM. Cerebellar extracts of P24 Cu− and Cu+ rats contained equivalent NO metabolite levels; furthermore, a 30kD 3‐nitrotyrosine containing peptide was detected in equal amounts in P24 Cu− and Cu+ cerebellar extracts. However, levels of CCS were markedly higher and CCO subunit IV nearly absent in Cu− lanes confirming severe Cu deficiency. Abundance of brain nNOS and eNOS mRNA, detected by real time qPCR, was not different between Cu− and Cu+ rat pups. We conclude perturbation in NO biology is unlikely to impact the altered development and metabolism of Cu− rat brain.

Supported in part by NIH HD‐39708.
Prenatal copper deficiency in rat dams causes persistent reduction in nuclear‐encoded cytochrome c oxidase subunits in cardiac mitochondria of the first generation
Authors: Johnson W Thomas , Anderson Cindy M
Published: June 2021

Previous studies have shown that the offspring of rat dams having low copper (Cu) intake during pregnancy and lactation experience a deficiency in cardiac cytochrome c oxidase (CCO) after postnatal day 10. The present study was undertaken to determine the relative influences of pre‐and postnatal Cu intake on CCO subunit content in cardiac mitochondria by cross fostering pups from dams fed AIN93G diet containing 1 mg Cu/kg (CuD dams) to dams fed diet containing 6 mg Cu/kg (CuA dams) and vice versa on postnatal day (PND) 1. Pups that remained with their birth dams served as controls. All dams began dietary treatment with either CuD or CuA diets 3 weeks before conception and remained on their respective diets until PND 21. On PND 21, no differences in the content of the mitochondrial‐encoded COX1 subunit occurred between the offspring of CuA dams, offspring of CuA dams cross fostered to CuD dams and offspring of CuD dams cross fostered to CuA dams. However, COX1 content was reduced 42% in the non‐cross fostered offspring of CuD dams. The content of the nuclear‐encoded COX4 subunit was reduced 28% in the offspring of CuD dams and the offspring of CuD dams cross fostered to CuA dams. These findings indicate that low prenatal Cu intake causes a persistent reduction in nuclear‐, but not mitochondrial‐encoded, CCO subunits in cardiac mitochondria in the F1 generation.
Identification of age‐related changes in gene expression in adult versus geriatric dogs
Authors: Frantz Nolan Z. , Yamka Ryan M. , Friesen Kim G. , Gao Xiangming , Al‐Murrani Samer
Published: June 2021

Thirty adult (<10 years of age) and thirty geriatric (>10 years of age) neutered/spayed beagles were identified for this study. Animals were fed a control food for 30 days and then a blood sample was drawn into a PAXgene Blood RNA tube. RNA was extracted according to the procedures provided in the PAXgene Blood RNA Kit Handbook (Qiagen, Valencia, CA). RNA was hybridized to an Affymetrix GeneChip Canine‐2 Genome Arrays and normalized using Robust Multi‐Array Average. Transcripts having a P < 0.01 (following a false discovery rate adjustment value of 0.1) and a fold change range of at least 1.5 were considered different among the two groups. Analysis of the RNA found differences in 580 genes between the geriatric and adult groups. Of the genes identified, 310 were up‐regulated and 270 down‐regulated in geriatric dogs when compared to adult dogs. Genes associated with immune system activation, cancer formation, B and T‐cell receptor signaling, protein ubiquitination, and branched chain amino acid degradation were increased, while cell‐cell signaling, cell cycle regulation, and blood coagulation were decreased in geriatric compared to adult dogs.
Piglets fed a weaning diet containing small amounts of arachidonic acid and docosahexaneoic acids have a lower proliferative response to dietary protein ex vivo compared to controls
Authors: Hosea Heather Joy , Goruk Susan D , Eklund Meike , Mosenthin Rainer , Christopherson Robert J , Field Catherine J
Published: June 2021

A growing body of evidence supports the inclusion of long chain polyunsaturated fats (PUFA) in infant formula. Their effects on immune function in weanlings are not known. This study measured the effects of PUFA in the weaning diet on phenotype, proliferation and cytokine production to a T/B cell mitogen (pokeweed), and two dietary proteins (ovalbumin and soy). At 21d of age, piglets (n=10/group) were randomized to a nutritionally complete control diet (15% w/w fat) or a diet with added arachidonic acid (AA, 0.6%)/docosahexaneoic acid (DHA , 0.4%) or DHA supplement (0.2%AA, 2% DHA, 0.3% eicosapentaenoic acid) for 14d. Proliferation (rate of 3H‐thymidine uptake), cytokine production (IL2, IL10, IFNg, TNFa, TGFb) and phenotype of mesenteric lymphocytes did not differ among diets. Although there was no effect on the response to pokeweed in Peyer's patch cells (PPc), AA/DHA PPc proliferated less (P<0.05) in response to dietary proteins compared to control. There was no effect of the DHA supplement diet on immune response or immune cell phenotype compared to control. In summary, these results suggest that PUFA in the weaning diet does not impair the immune response to a T/B cell mitogen. The lower PPc response to dietary proteins with AA/DHA suggests a positive effect on oral tolerance. Funding provided by CIHR.
Pediatricians or Grandma…who influences WIC participants’ ideal of infant fatness?
Authors: Grissom M. Joy , Jahns Lisa , Kavanagh‐Prochaska Katherine
Published: June 2021

Rapid rate of weight gain in infancy has been associated with later risk of overweight. Parental attitudes about desired infant fatness could affect this rapid gain. The objective of this study was to examine perceptions of what infant fatness is desired among parents, and if perceived desired infant fatness from important figures such as grandmother (G), pediatrician (P), and other caregivers (OC) differs from parental desires. During scheduled WIC nutrition education classes, parents of 106 0–6 mo old infants completed a novel modification of the Rand Infant Fatness Scale, an ordinal drawn scale of 9 infants from thin to heavy. Parents were asked to circle the picture most representative of the fatness they desired their infant to be at 6 mo of age, and which infant they perceived their G, their P, and OC (if relevant) desired. Mean infant age was 5.1 mo. Desired infant fatness was positively correlated with perceived desires of G, P, and OC (r = 0.533, 0.674, 0.375, respectively; p <0.05). In conclusion, 14–45% of the variance in parental desire was explained by the perceived influence of G, P, and OC. Perceived desire of the P and G was most strongly correlated with parental desire of appropriate infant fatness, indicating that pediatricians and grandmothers may be most influential for interventions targeting appropriate infant weight gain. Support: The University of Tennessee.
Relatives’ migration to the US and overweight among Mexican school‐age, rural children
Authors: Flores Mario , Macias Nayeli , Rivera Marta , Merlos Claide , Barquera Simon
Published: June 2021

The objective was to evaluate the influence of relatives’ migration to the US on weight status among rural Mexican children. Anthropometric measurements, body composition and physical activity were assessed in a cross‐sectional study of 119 school‐age children (9–12y) with at least one household member living in the US and sending remittances, and 120 community‐matched children who did not have a relative living in the US. Data on physical activity was obtained (steps/d during 7d). BMI was calculated as W/H2(kg/m2). Mean age was 10.9 ± 1.03y. Mean BMI was 20.4 ± 4.1. Average steps/d was 12,359 ± 4487. Mean percent body fat was 35.4 ± 7.9. Forty‐seven percent were girls. According to Cole's BMI cutoffs, 52.2% of children had normal weight, 28.4% were overweight, and 13.4% were obese.

After adjusting by age and community, logistic regression analysis showed a 35% reduction in the risk of obesity, per 1000 steps/d, among girls with a migrant relative (OR: 0.65, 95%CI: 0.44, 0.97). Among those without a migrant relative, a 19% reduction in the risk of obesity per 1000 steps/d was observed in boys, but not in girls (OR: 0.81, 95%CI: 0.68, 0.98), (p for interaction=0.067).

A relative's migration to the US is related to sex‐differential effects of physical activity in weight status among these rural Mexican school‐age children.

Funded by CONACyT, Mexico; No. 2005–01–14089.
Impact of dairy products and dietary calcium on bone mineral content in children: Results of a meta‐analysis
Authors: Huncharek MIchael , Muscat Joshua , Kupelnick Bruce
Published: June 2021

Objective: Although calcium is essential for maintaining bone health in children, the optimum dietary intake of calcium in this age group, particularly in the form of dairy foods, is a matter of debate. A meta‐analysis was conducted to examine the impact of dietary calcium/dairy supplementation on bone mineral content in this age group.

Methods: Data were pooled from randomized controlled intervention trials and observational studies using previously described methods. The outcome of interest was a summary mean difference bone mineral content.

Results: Combining data from twenty‐one randomized controlled trials (RCTs) using total body bone mineral content (TB‐BMC) as the outcome of interest, yielded a non‐statistically significant increase in TB‐BMC of 2 grams. These data demonstrated substantial statistical heterogeneity with sensitivity analyses revealing that among study subjects with normal or near normal baseline dietary calcium/dairy intakes, supplemental dairy/calcium showed little impact on bone mineral content. Sensitivity analyses suggested that baseline calcium intake could potentially account for the statistical heterogeneity. Pooling the three reports utilizing low intake subjects yielded a statistically significant summary mean BMC of 49 grams (24.0–76‐6). Pooling two RCTs using calcium/dairy supplement plus vitamin D was also associated with an increase in lumbar spine BMC of, on average, 35g (−6.8–41.8).

Conclusion: Increased dietary calcium/dairy products, with and without vitamin D, significantly increases total body and lumbar spine BMC in children. Among children with “high baseline intakes” supplemental calcium/dairy products had little effect on TB‐BMC.
Effects of food form and portion size on postprandial appetite, ghrelin, and energy expenditure in healthy, older adults
Authors: Leidy Heather J , Apolzan John W , Mattes Richard D , Campbell Wayne W
Published: June 2021

Objective: To examine the independent and combined influences of food form and portion size on appetite and metabolic responses. Methods: 43 older men and women (age: 72 ± 1 y; BMI: 25.6 ± 0.3 kg/m2) consumed, on 2 separate days, preloads in solid (S) vs. beverage (B) form as either 12.5% (264 ± 8 kcal) or 25% (533 ± 14 kcal) of estimated daily energy need. Postprandial (PP) appetite (hunger, fullness, desire to eat), plasma ghrelin concentration, and energy expenditure (EE) were measured over 4 h. Results: Main effects of food form (p<0.05) and portion size (p<0.05) were observed for appetite; PP hunger and desire to eat area under the curve (AUC) values were higher and fullness AUC values were lower for B vs. S and between 12.5% vs. 25%. Post‐hoc analyses revealed no difference in appetite between the S‐12.5% vs. S‐25%. However, B‐12.5% led to higher hunger and desire to eat and lower fullness AUC values vs. the B‐25% (p<0.05). No difference in 4‐h ghrelin was observed between S vs. B and 12.5% vs. 25%. Concerning PPEE, the B treatment led to lower overall PPEE vs. S when consuming 25% (p<0.01) but not 12.5%. Conclusion: Several key parameters of appetite appear to be independently and additively influenced by food form and portion size with particular insensitivity to lower energy beverages in healthy, older adults.

Support: NIH R01 AG021911; The Solae Company; IBRC, Purdue University
A dose‐response effect from cocoa consumption on biomarkers of oxidative stress and inflammation in adults at risk for insulin resistance
Authors: Stote Kim S. , Clevidence Beverly A. , Baer David J.
Published: June 2021

This study investigated if there was a dose‐response effect of cocoa flavanols on biomarkers of oxidative stress and inflammation in adults at risk for insulin resistance. The study then compared the effect of the high dose cocoa and green tea on these outcomes. As part of a randomized crossover design, 20 obese subjects consumed a controlled diet with 5 treatments: 1) high dose cocoa (900 mg/d of flavanols), 2) medium dose cocoa (400 mg/d of flavanols), 3) low dose cocoa (200 mg/d of flavanols), 4) control cocoa (22 mg/d of flavanols), and 5) green tea (catechins matched for high dose cocoa). For five days, the treatments were consumed with breakfast and dinner. On the sixth day, after a 12 h fast, subjects consumed a 75 g glucose solution. Biomarkers (8‐isoprostanes, CRP, IL‐6, ICAM and fibrinogen) were measured during a 2 h period. Results showed that as the cocoa dose increased, 8‐isoprostanes decreased (p=0.02) with the medium dose having the maximal lowering effect. CRP decreased (p=0.01) as the cocoa dose increased. IL‐6 was lowered (p=0.0001) by the medium dose cocoa. Cocoa did not significantly affect ICAM and fibrinogen. When the high dose cocoa was compared to the green tea, the green tea lowered fibrinogen (p=0.0003) but no significant effects were observed on 8‐isoprostanes, CRP, IL‐6, and ICAM. Cocoa flavanol consumption of 400 mg/d or above may improve some important biomarkers of oxidative stress and inflammation.
Targeted expression of cyclooxygenase‐2 in hepatocytes accelerates LPS‐induced acute liver failure
Authors: Han Chang , Lim Kyu , Li Guiying , Xu Lihong , Wu Tong
Published: June 2021

Bacterial lipopolysaccharide (LPS) is implicated in the pathogenesis of acute liver failure and several chronic inflammatory liver diseases. To evaluate the effect of hepatocyte cyclooxygnese‐2 (COX‐2) in LPS‐induced liver injury, we generated transgenic mice with targeted expression of COX‐2 in the liver by using the albumin promoter‐enhancer driven vector and the produced animals were subjected to a standard experimental protocol of LPS‐induced acute fulminant hepatic failure (intraperitoneal injection of low dose of LPS in combination with D‐galactosamine (GalN)). The COX‐2 transgenic mice exhibited earlier mortality, higher serum ALT and AST levels and more prominent liver tissue damage than wild type mice. Western blot analysis of the liver tissues showed that LPS/D‐GalN treatment for 4 hours induced the cleavage of PARP, caspase‐3 and caspase‐9 in COX‐2 transgenic mice but not in wild type mice. Increased hepatic expression of JNK2 in COX‐2 transgenic mice suggests that upregulation of JNK2 may represent a potential mechanism for COX‐2‐mediated exacerbation of liver injury. Blocking the prostaglandin receptor, EP1, prevented LPS/D‐GalN‐induced liver injury and hepatocyte apoptosis in COX‐2 transgenic mice. These findings suggest that blocking COX‐2/EP1 pathway may represent an effective approach for attenuation of LPS‐induced liver injury.
Comparative effect of 5α‐dihydrotestosterone (DHT) and 17β‐estradiol (E2) on norepinephrine (NE)‐induced hypertrophy in neonatal rat ventricular myocytes (NRVM)
Authors: Koshman Yevgeniya E , Russell Brenda , Gu Lianzhi , Piano Mariann , Schwertz Dorie
Published: June 2021

Cardiac hypertrophy increases after menopause. As a result the potential role of E2 has been examined while the role of DHT is understudied. We compared the effect of DHT to E2 on markers of NE‐elicited hypertrophy in NRVM including: 1) cell surface area (CSA), 2) myofibrillar organization by actin staining, 3) fetal gene expression by real‐time RT‐PCR and 4) ERK activation (ERK∼P/ERK‐total) by Western blot. NRVMs were exposed to NE (1μM), E2 (10nM), DHT (100nM), E2+NE, or DHT+NE in phenol‐free DMEM for 48 hrs (n=3). Compared to control, NE nearly doubled CSA and greatly increased actin fiber alignment and organization. E2 decreased and DHT increased CSA but both induced myofibrillar disorganization. E2 and DHT reduced NE‐elicited augmentation of CSA and myofibrillar organization. CSA was greater in DHT than E2‐exposed cells regardless of NE treatment. E2 alone did not alter fetal gene expression whereas DHT increased α‐myosin heavy chain (MHC) and sarcoplasmic reticular calcium ATPase. NE increased expression of β‐MHC, skeletal actin, ANP and BNP, but neither E2 nor DHT altered the NE response. ERK∼P to total ERK ratio was not altered by any treatment. In conclusion, similar to E2, DHT reduces hypertrophy but not gene expression or ERK activation after 48 hrs of NE exposure. Supported by NR009014 & HL62426
Short‐term (S‐T) magnesium (Mg)‐deficiency (MD) results in decreased levels of serum sphingomyelin and apoptosis in in‐vivo cardiac tissues and aortic smooth muscle:Implications for sphingolipids(SPH) in cardiovascular diseases(CVD)
Authors: Altura Burton M. , Shah Nilank C. , Jiang Xian‐Cheng , Li Zhiqiang , Altura Bella T.
Published: June 2021

We have shown in vascular muscle cells that variation in free Mg2+ caused changes in membrane(M) phospholipids, second messengers and M oxidation. Decreased [ Mg2+]o produced a fall in M sphingomyelin (SM); increased [Mg2+]o raised intracellular ceramide. Low Mg content in drinking water is associated with high incidences of CVD. Using S‐T (21 days) dietary deficiency of Mg ( 10% normal intake) in Wistar rats, and ISEs to measure serum free Mg2+, we determined whether S‐T MD would : 1) lead to reductions in serum SM, DNA‐fragmentations(DNA‐fr), lipid peroxidation (LP), and activation of caspase‐3 (CAS‐3) in cardiac (CA) and aortic smooth muscle (AM);and 2) whether imbibing Mg in drinking water would inhibit/reverse these effects of MD. The MD‐animals were allowed to drink triply‐distilled water containing different levels of Mg; controls received a normal Mg diet. Left & right ventricles, atria and abdominal aorta were analysed. Data indicate that S‐T MD resulted in reductions in s‐Mg2+, lowering of s‐SM, LP, DNA‐fr and activation of CAS‐3 in CA and AM. Water‐borne Mg attenuated or inhibited the reductions in s‐SM and activation of LP, DNA‐fr and CAS‐3. We conclude: 1) S‐T MD results in a down‐regulation of SM synthase and, most likely, generation of SPH, which could account, in part, for MD‐induced cardiovascular pathologies; and 2) water‐borne, bioavailable Mg would appear to be cardioprotective in rats.
The Inflammatory and Fibrotic Response in the Murine Pressure‐overloaded Heart
Authors: Xia Ying , Corbett Daniel , Li Na , Mendoza Leonardo , Lee Keunsang , Frangogiannis Nikolaos
Published: June 2021

Cardiac pressure overload results in hypertrophy and fibrotic remodeling of the ventricle. We hypothesized that development of fibrosis in the pressure‐overloaded heart may be preceded by activation an inflammatory cascade; subsequent induction of inhibitory pathways (such as TGF‐β) may suppress inflammation while inducing fibrosis. C57/BL6 mice underwent transverse aortic constriction (TAC) protocols. Chemokine (MCP‐1, MIP‐1alpha, RANTES and Lymphotactin) and pro‐inflammatory cytokine (TNF‐alpha and IL‐1beta) expression was induced in the pressure overloaded heart after 3–7 days of TAC. Upregulation of inflammatory mediators was associated with perivascular and interstitial macrophage infiltration. Induction of pro‐inflammatory mediators was followed by a late upregulation of TGF‐β isoforms associated with expression of the matricellular proteins tenascin‐C, OPN and TSP‐1. Inflammatory activity decreased after 28 days of TAC; at this timepoint established fibrosis was noted. The development of fibrosis was associated with cardiac hypertrophy, ventricular dilation and systolic dysfunction. In the pressure overloaded heart, late induction of inhibitory mediators, such as TGF‐β, may suppress inflammation while inducing fibrosis. Experiments using genetically targeted animals will dissect the mechanisms responsible for fibrotic remodeling of the ventricle (R01 HL‐76246).
Global histone H3 lysine 4 methylation patterns in human breast cancer
Authors: Rivenbark Ashley Garrett , Livasy Chad A. , Wells Wendy A. , Tsongalis Gregory J. , Coleman William B. , Strahl Brian D.
Published: June 2021

Posttranslational modifications of histones are regulators of gene expression, and their misregulation is associated with development of cancer. Histone methylation occurs on lysine residues, established by enzymes that regulate chromatin structure and gene activity. The ability of histone methylation to regulate the different states of chromatin depends on the lysine that is targeted and the methylation state (mono‐ di‐, or trimethyl) that these enzymes create. Methylation on histone H3 lysine 4 (H3K4) correlates with gene activity and the H3K4 methyltransferase, MLL, is translocated in hematological cancers. The H3K4 demethylase, PLU‐1, has been implicated in breast cancer cell proliferation. The pattern of histone modification disruption in tumors has been largely unexplored. We examined by immunohistochemistry the global H3K4 di‐ and trimethylation patterns on a human breast tumor microarray. The majority of breast tumors were positive for H3K4 dimethylation, and 21% (16/76) of tumors showed either reduced or differential nuclear staining for H3K4 trimethylation. These results suggest H3K4 trimethylation is coupled to the pathology of breast cancer and reveal this approach to be useful for the analysis of histone modification profiles associated with cancer types. Future studies will determine if this and other histone methylation marks are clinically relevant indicators of patient assessment.
MicroRNA 10a/10b regulation of endothelial phenotype in atherosusceptible and protected sites in adult swine aorta
Authors: Shi Congzhu , Fang Yun , Karamanian Armen , Manduchi Elisabetta , Davies Peter F
Published: June 2021

Endothelial phenotypes in susceptible arterial regions of adult swine display a balance of pro‐pathological and protective transcript profiles. Regulation of mRNA stability and translation occurs by highly conserved small non‐coding microRNAs (miRNAs). Microarrays identified 3 miRNA families (let‐7, miR10, miR26) as upregulated in endothelium from an atheroprotected region of thoracic aorta relative to a nearby atherosusceptible region (aortic arch). By qRT‐PCR, expression levels of miR10a and 10b were 4.9 and 20.7‐fold higher respectively at protected (n=8) vs susceptible (n=10) regions; in contrast miR7d and miR26b were elevated <2‐fold. 854 putative targets of miR10a/b were organized into interactive pathways using IngenuityTM. Sequences of 138 of the most interactive genes were entered into the Sfold program that assesses target secondary structure as an important predictor of miRNA‐target hybridization sensitivity. Among miR10a/b targets showing high total hybridization energy were Flt‐1 (VEGFR1), Hox‐D10 and VEGFA. Endothelial expressions of these genes were suppressed in protected vs susceptible regions in a reciprocal relationship with miR10a/b. Cultured endothelial cells overexpressing miR10b suppressed Flt‐1 gene expression. The data suggest miR10a/b to be important regulators of endothelial gene expression in atheroprotection/susceptibility. Grant support from NHLBI.
Endothelial Dysfunction and the Pathobiology of Accelerated Atherosclerosis in Hutchinson‐Gilford Progeria Syndrome
Authors: Yap Belinda , Garcia‐Cardena Guillermo , Gimbrone Michael A.
Published: June 2021

A prominent feature of Hutchinson‐Gilford Progeria Syndrome (HGPS) is premature, severe atherosclerosis, resulting in fatal heart attacks and strokes. Given the critical role of endothelial dysfunction in atherogenesis, we explored the effects of progerin (the mutant gene product in HGPS) on endothelial pathobiology, utilizing a model system in which cultured human endothelial cells (EC) express progerin via adenoviral infection. Progerin accumulation in EC results in a strikingly abnormal nuclear morphology, observed as aggregation of progerin and other nuclear proteins. Accumulation of progerin also induces a proinflammatory/atherogenic program of EC activation characterized by 1) sustained expression of leukocyte adhesion molecules (VCAM‐1, E‐selectin) and proinflammatory cytokines (IL‐8, MCP‐1); 2) expression of prothrombotic genes (PAI‐1); 3) decreased expression of eNOS; and 4) downregulation of KLF2, a transcription factor critical to endothelial homeostasis. Further, conditioned medium from progerin‐expressing EC induces dysfunction when transferred onto control EC. Thus, progerin accumulation in EC appears to induce a state of chronic dysfunction, via autocrine/paracrine pathways, potentially contributing to the premature and accelerated atherosclerosis of HGPS.
The protein arginine methyl transferase PRMT5 binds to HOXA9 and participates in cytokine induction of E‐selectin in endothelial cells
Authors: Bandyopadhyay Smarajit , Adams Greg , McHugh Anne , Money Angela , DiCorleto Paul E.
Published: June 2021

The homeobox gene HOXA9 is an important regulator of endothelial cell (EC) differentiation and activation. We have recently identified a specific pro‐inflammatory role for HOXA9 in the cytokine induction of the EC‐leukocyte adhesion molecule E‐selectin in EC. However, HOXA9 often requires other interacting proteins to exert its effect on gene expression. Here we show that the type II protein arginine methyl transferase PRMT5 is a novel binding partner of HOXA9 in TNF‐α‐activated EC. We identified PRMT5 binding to HOXA9 using a co‐immunoprecipitation and proteomics approach. Recent studies of others have implicated PRMT5 in a number of cellular processes, including both positive and negative transcriptional regulation. Depletion of PRMT5 protein in EC by specific siRNA resulted in a significant and specific decrease in TNF‐α‐induced E‐selectin gene expression. In addition, PRMT5 specifically activated the E‐selectin gene promoter in EC. Chromatin immunoprecipitation (ChIP) assays showed that PRMT5 is associated transiently with the E‐selectin promoter region containing the previously identified HOXA9 recognition sequence. The kinetics of the association correlates with the presence of HOXA9 on the promoter. These findings provide the first evidence that PRMT5 association with HOXA9 may be important for transcriptional regulation of the E‐selectin gene during EC activation. (HL29582).
Inhibition of Soluble Epoxide Hydrolase (sEH) Attenuates Cisplatin‐Induced Acute Renal Inflammation
Authors: LIU Yingmei , Webb Heather , Kroetz Deanna L
Published: June 2021

Epoxyeicosatrienoic acids (EETs) are cytochrome P450‐derived eicosanoids which are metabolized into dihydroxyeicosatrienoic acids by sEH. EETs are found at high levels in the kidney and have anti‐inflammatory effects, leading us to hypothesize that inhibition of sEH would attenuate renal inflammation. Treatment of C57BL/6 mice with cisplatin resulted in a dose‐dependent increase in blood urea nitrogen (BUN), serum creatinine (CREA), and renal levels of neutrophil gelatinase‐associated lipocalin (NGAL). Pretreatment of mice with a novel sEH inhibitor, AR9273, attenuated the increase in cisplatin‐induced BUN and CREA level by 34% (p < 0.05) and 45% (p < 0.01). NGAL expression was barely detectable in cisplatin‐treated mice pretreated with AR9273. The cisplatin‐induced elevation of cyclooxygenase 2 expression in the kidneys was also dramatically reduced in mice treated with AR9273. The effect of cisplatin treatment on BUN and CREA was significantly attenuated in Ephx2−/− mice compared to Ephx2+/+ mice. Collectively, these data suggest that inhibition of sEH protects against renal inflammation. This work was supported by UC Discovery Grant bio06‐10576.