bluuebunny/crossref_metadata_2025 huggingface dataset:
Probing Microbial Interactions With The Mucus Barrier
Authors: Ribbeck Katharina
Published: November 2023

Mucus is a biological gel that lines all wet epithelia in the body, including the eyes, lungs, and digestive tracts, and has evolved to protect us from pathogenic invasion. Microbial pathogenesis in these mucosal systems, however, is often studied in mucus‐free environments, which lack the geometric constraints and microbial interactions that are found in natural, three‐dimensional mucus gels. To bridge this gap, my laboratory has developed model test systems based on purified mucin polymers, the major gel‐forming constituents of the mucus barrier. We use these models to understand how the mucus barrier influences bacterial virulence, and moreover, to elucidate strategies used by microbes to overcome the normal protective mucus barrier. I will discuss data showing that the mucus environment has a significant impact on the physiological behavior of microbes, including surface attachment, quorum sensing, the expression of virulence genes, and biofilm formation. The picture is emerging that mucins are key host players in the regulation of microbial virulence and are critical to consider when studying mucosal pathogenesis.
Combined metabolomic and fluxomic assays suggest the existence of multiple pools of glucose‐6‐phosphate in perfused muscle
Authors: Previs Stephen , Herath Kithsiri , Petrov Aleksandr , Castro‐Perez Jose
Published: November 2023

Glucose uptake and utilization (e.g. deposition in glycogen vs oxidation to CO2) by skeletal muscle represents a critical step to ensuring normal metabolic homeostasis. The ability to modulate glucose flux in muscle is of interest since it may affect better glucose control in subjects with impaired insulin action and/or overt diabetes. We initiated studies that used isolated perfused rat hindlimb as a model system in order to identify molecules that could alter glucose uptake and utilization, metabolomic and fluxomic analyses were used to track the fate of glucose molecules. Typical studies relied on 30–60 min open circuit perfusions, soleus and gastrocnemius were then dissected and freeze clamped. Samples were processed using standard homogenization steps and subjected to LC‐MS analyses. The data suggest greater uptake of 2‐deoxyglucose in soleus vs gastrocnemius under baseline conditions. The incorporation of [13C]glucose was then followed into glucose‐6‐ and glycerol‐3‐phosphate, lactate and several TCA cycle intermediates. The observed [13C]labeling patterns clearly demonstrate the generation of [13C]lactate but suggest minimal conversion of [13C]glucose to [13C]TCA cycle intermediates. Parallel labeling studies with [13C]acetate demonstrate [13C]labeling in the TCA intermediates, implying that mitochondria are active in the resting perfused muscle but that the muscle does not completely oxidize glucose. A striking observation however centers on a discrepancy between the enrichments of glucose‐6‐ vs glycerol‐3‐phosphate, the latter being much higher than the former (consistent in both muscles). The discrepancy in the [13C]labeling patterns can be explained by the existence of multiple pools of glucose‐6‐phosphate. These observations agree with previously reported data in hepatocytes and have important implications if/when one aims to use concentration profiles to infer aspects of metabolic control. For example, concentrations of glucose‐6‐phosphate are believed to play a central role in effecting glucose uptake (e.g. feedback inhibition). However, the existence of multiple pools complicates interpretations when one aims to link a change in metabolite concentration to a change in metabolic flux. We believe that one can use tracers to estimate overall flux rates but one should exercise caution when using concentration profiles to explain metabolic control points and therein identify reactions that are targeted by pharmacological manipulations.

Support or Funding Information

All authors were employed by Merck during the completion of these studies.
Effect of Dietary Coconut Oil and Conjugated Linoleic Acid on Liver Metabolic Phenotype in Mice
Authors: Barnes Kimberly M. , Engle Jake P. , Chen Qiannan , DiGregorio Anna M. , McFadden Joseph W.
Published: November 2023

Mice fed coconut oil (CO) lose more body fat when fed conjugated linoleic acid (CLA) than mice fed soy oil (SO), in part due to increased basal lipolysis. These mice also have increased liver fat content but changes in specific liver metabolites are largely unknown. Our objective was to use mass spectrometry‐based metabolomics to determine the metabolic profile of mice fed CO and/or CLA. Male mice from 4 common strains (CF‐1, Swiss Webster, ICR, and NIH; n=24 each) were obtained at weaning, fed either CO or SO for 6 wk, then 0 or 0.5% CLA for an additional 12 d. Following liver homogenization and methanol extraction, metabolites were profiled using electron impact ionization, gas chromatography, and mass spectrometry. Mass spectral analyses with standards resulted in a total of 37 identifiable metabolites. For untargeted metabolomics data, statistics were performed on the log of the normalized and autoscaled data. As reported previously, we detected an oil x CLA interaction (P < 0.05) on body fat, with CO+CLA‐fed mice being the leanest. Basal lipolysis was increased by both CO (P < 0.001) and CLA (P < 0.01), with CO+CLA‐fed mice having the greatest rate of NEFA release. Principle component analysis (PCA) revealed that the first three components accounted for 36% of the variation in the samples, and no more than three metabolites fell outside the 95% confidence ellipse. For the first three components, metabolites with variable importance of projection (VIP) scores greater than 2.0 were linoleic acid and oleic acid. PCA also indicated that dietary oil (CO or SO) had a greater effect on liver metabolites than CLA. CO‐fed mice also showed less variation in metabolites when fed CLA than did SO‐fed mice. Eleven metabolites were altered by diet, with fatty acid changes that correspond with the dietary oils being the most significant. Other metabolites altered include phosphoric acid (decreased by CO, P < 0.01), proline (decreased in CO+CLA‐fed mice vs all other diets, P < 0.05), β‐hydroxybutyrate (BHBA; increased in CO+CLA‐fed mice vs SO and SO+CLA‐fed mice with CO‐fed mice being intermediate, P < 0.05), and acetic acid and isoleucine (both decreased in CO+CLA‐fed mice vs SO and SO+CLA‐fed mice, P < 0.05). Very few differences were detected between the different strains of mice. The increased lipid mobilization in the CO+CLA‐fed mice may account for the increased ketone bodies and could require greater protein synthesis as well, thus accounting for the decreased amino acid concentrations. This is supported as BHBA was negatively correlated with linoleic acid, valine, and phosphoric acid (P<0.05; r = −0.34 to −0.24) and positively correlated with glycerol (P<0.05; r = 0.25).
Watermelon and L‐Arginine Consumption Regulate Gene Expression Related to Serum Lipid Profile, Inflammation, and Oxidative Stress in Rats Fed an Atherogenic Diet
Authors: Beidler Joshua , Hooshmand Shirin , Kern Mark , Figueroa Arturo , Hong Mee Young
Published: November 2023

Watermelon (Citrullus lanatus) is rich in L‐citrulline, a precursor of L‐arginine that may reduce cardiovascular disease (CVD) risk. The purpose of this study was to investigate the effects of watermelon powder and L‐arginine supplementation on lipid profiles, antioxidant capacity, and inflammation in rats fed an atherogenic diet. We hypothesized that watermelon and L‐arginine would increase antioxidant capacity and reduce blood lipids and inflammation by modulating hepatic expression of key genes. Three‐week‐old male‐weanling Sprague‐Dawley rats (total N = 32) were assigned to 3 groups and fed diets containing watermelon powder (0.5% wt/wt; n = 11), L‐arginine (0.3% as 0.36% L‐arginine HCl wt/wt; n = 11), or a control diet (n = 10) for 9 weeks. Food and water intake, body weight, and epididymal fat mass did not differ among the 3 groups of rats. However, watermelon and L‐arginine supplementation exhibited lower serum concentrations of triglycerides, total cholesterol, and low density lipoprotein cholesterol compared to control (P< .05). There were no significant differences for high‐density lipoprotein cholesterol. The watermelon and L‐arginine groups had significantly lower serum levels of C‐reactive protein than the control group (P< .05). Superoxide dismutase, glutathione S‐transferase, and total antioxidant capacity were higher in the watermelon and L‐arginine groups compared with controls (P< .05). Activities of catalase, glutathione peroxidase, and glutathione reductase were not significantly different. Compared with rats consuming the control diet, rats consuming watermelon and L‐arginine exhibited significant upregulation of endothelial nitric oxide synthase (P< .05) and significant downregulation of fatty acid synthase, 3‐hydroxy‐3‐methyl‐glutaryl‐CoA reductase, sterol regulatory element‐binding protein 1, sterol regulatory element‐binding protein 2, cyclooxygenase‐2, and nuclear factor NF‐kappa‐B p65 (P< .05). There were no significant differences in expression of inducible nitric oxide synthase. In conclusion, these results support the hypothesis that watermelon improves CVD risk factors including lipid profile, oxidative stress, and inflammation by altering hepatic gene expression in a manner similar to L‐arginine supplementation.

Support or Funding Information

The study was funded by the US National Watermelon Promotion Board and the Kasch‐Boyer Endowed Scholarship in Exercise and Nutritional Sciences in San Diego State University.
Agent‐based Modeling of Social Norm Impacts on Obesity and Eating Behaviors among School Children in China and the United States
Authors: Xue Hong , Zhang Jun , Xu Fei , Wang Youfa
Published: November 2023

Objectives

Although the importance of social norms in affecting health behaviors has been increasingly recognized, the current understanding of social norm effects on obesity is limited due to data and methodology limitations. This study aims to use nontraditional innovative systems science methods to examine: a) the effects of social norms on school children's BMI growth and fruit and vegetable (FV) consumption in China and in the US, and b) compare the difference in social norm effects in different social settings.

Methods

We built an agent‐based model (ABM) in a utility maximization framework and parameterized the model based on empirical longitudinal data collected in Nanjing, China, in the Childhood Obesity Prevention through Physical Activity Promotion in China study and in the US in the Early Childhood Longitudinal Study – Kindergarten Cohort (ECLS‐K) to test the follow‐the‐average social norm affecting children's BMI growth and FV consumption.

Results

The correlation between observed and ABM‐predicted BMI was about 0.9, indicating the satisfactory performance of our ABMs. Our simulations suggested the follow‐the‐average social norm acts as an endogenous stabilizer, which automatically adjusts positive and negative deviance of an individual's BMI from the group mean of a social network. In China, our simulation analysis suggests that social norms may lead to a 0.05 (kg/m2) BMI increase for those with one unit of BMI below the average, and a 0.045 (kg/m2) decrease for those with one unit of BMI above the average. In the US, corresponding social norm effects were much smaller than those in China, being 0.025 (kg/m2) and 0.015 (kg/m2) per BMI unit differences above or below the social average, respectively. Our simulation also showed that misperception of the social norm would push up the mean BMI and cause the distribution to be more skewed to the left. Our simulation results did not provide strong support for the role of social norms on FV consumption.

Conclusions

Social norms influence children's BMI growth in China and the US, with greater effects in Chinese children. High obesity prevalence will lead to a continuous increase in children's BMI due to increased socially acceptable mean BMI. Interventions promoting healthy body image and desirable socially acceptable BMI should be implemented to control the childhood obesity epidemic.

Support or Funding Information

NIH, U54 HD070725, 1R01HD064685‐01A1
Evaluation of High School Students' Intrinsic Motivation and Perceived Competence to Cook Using the Adolescent Motivation to Cook Questionnaire
Authors: Miketinas Derek , Cater Melissa , Bailey Ariana , Rhea Kwadernica , Tuuri Georgianna
Published: November 2023

The Self‐Determination Theory (SDT) is a macrotheory of human motivation which asserts that individuals are more likely to perform a behavior or task if they are intrinsically motivated as opposed to externally motivated or amotivated. Nutrition education and culinary skills‐building programs based upon the SDT may improve participants' motivation to cook healthy foods. The Adolescent Motivation to Cook Questionnaire (AMCQ) measures the psychosocial constructs identified by the SDT as they relate to food preparation and the learning environment. The purpose of this study was to measure change in high school students' intrinsic motivation (IM) and perceived competence (PC) to prepare healthy foods as a result of completing a 6‐week nutrition‐education and culinary skill‐building program. The program was offered as a school‐based or community‐center summer enrichment program. The curriculum aimed to improve students' motivation and confidence to cook through hands‐on culinary practice and instruction. Forty‐eight participants (60% female) completed the program; the mean age of the participants was 14.9 ± 0.9 years. Of the 46 adolescents who provided racial/ethnic information, 39 (81%) were African Americans, 3 (6%) were Hispanics, and 4 (8%) indicated Other. Students were in the following grades: 25 (52%) 9th grade, 14 (29%) 10th grade, 7 (15%) 11th grade, and 2 12th grade. After participating in the program, the students reported a significant mean change from baseline for IM (p<0.0001), PC (p<0.001) and relatedness among classmates (p < 0.05). An increase in IM was positively associated with changes in PC (p<0.01), autonomy support (p<0.05), and autonomy (p<0.01). The results of this study support the SDT constructs and provide evidence that participation in a nutrition‐education and culinary skill‐building program increases high school students' IM and PC to cook.

Support or Funding Information

Partially funded by Hatch Project 94127.
3D Imaging Technology for Human Body Size and Shape Analysis: Comparison of Three Different Acquisition Technologies
Authors: Bourgeois Brianna , Latimer Dustin , Stannard Casey R , Romeo Laurel , Li Xin , Shepherd John , Ng Bennett K , Heymsfield Steven B
Published: November 2023

Anthropometric measurements of body size and shape are widely used in diagnosing, monitoring, and assessing the risk of developing adiposity‐related chronic metabolic diseases. Recent technological advances have extended anthropometry beyond traditional tape‐derived measurements to automated 3D digital image acquisition devices that can rapidly acquire hundreds of linear, circumferential, and volumetric body dimensions. The aim of the current study was to compare measures across three imaging devices differing in acquisition and data processing technology (16 stationary Microsoft Kinect Cameras (MKC)[KX16, TC2]; and single vertical movable optical light‐coding camera [Proscanner, Fit3D Inc.] or stationary MKC V2 camera [Styku, Inc.] with 3600 rotating platforms) and against traditional reference methods including total body volume (TBV) by air displacement plethysmography (ADP), circumferences by tape anthropometry, and regional body volume by dual‐energy x‐ray absorptiometry (DXA). Subjects were 32 healthy adults (15 male, 17 female). TBVs measured by all three systems were highly inter‐correlated and significantly correlated with ADP‐derived TBV (respective R2's, 0.94, 0.97, and 0.96; all p<0.001). Regression line slopes were non‐significant in Bland‐Altman plots for KX16 and Fit3D and significant (p=0.001) for Styku. Relative to tape measurements, good correlations were observed for all circumferences derived by 3D devices (e.g., right bicep, R2's, 0.67, 0.94, 0.86; hip, R2's 0.67, 0.74, 0.83). Regional body volumes measured by each system were highly correlated with corresponding DXA volumes (e.g., trunk, R2's, 0.93, 0.94, 0.96; all p<0.001). Potentially research and clinically useful 3D imaging systems compare favorably with corresponding reference methods with similar overall results largely independent of acquisition technology.
Myeloid Derived Suppressor Cells (MDSC) Are Vitamin D Targets and 1α, 25 Dihydroxyvitamin D (1,25(OH)2D) Inhibits their Ability to Suppress T Cell Function
Authors: Calvert Ryan D , Burcham Grant N , Ratliff Timothy L , Fleet James C
Published: November 2023

Tumors have a complex microenvironment that includes MDSC, an immune cell that is recruited to the tumor and which suppresses the ability of cytotoxic T cells to attack and clear tumor cells from the body. The active, hormonal form of vitamin D, 1,25(OH)2D, regulates many components of the immune system and previous research shows that 1,25(OH)2D reduces the number of CD34+ cells, an MDSC precursor, in tumors. This suggests MDSC may be direct vitamin D target cells. To test this, we examined whether the MDSC subsets in tumors (granulocyte‐like; G‐MDSC, or monocyte‐like; M‐MDSC) or their immature myeloid cell (iMC) precursors in bone marrow (G‐iMC, M‐iMC) express the vitamin D receptor (VDR), an essential mediator of 1,25(OH)2D molecular action. VDR mRNA levels are low in iMC subsets in marrow and increase by 20‐fold in tumor MDSC. In addition, at both sites M‐subtype cells have 4‐fold higher VDR expression than G‐subtype cells. We subsequently conducted several experiments to test whether MDSC were responsive to 1,25(OH)2D. Bone marrow iMC were isolated by flow cytometry and induced to differentiate into tumor MDSC‐like cells with a cytokine cocktail of IFN‐γ, IL‐13, and GM‐CSF. This treatment increased VDR expression 100 fold and activated the T cell suppressive function of MDSC within 72 h. 1,25(OH)2D treatment (10 nM for 24 h after treatment with cytokines for 48 h) increased expression of the classical vitamin D target gene, CYP24A1, in wild‐type (WT) cells but not VDR knockout (KO) cells. In addition, 1,25(OH)2D treatment reduced the T cell suppressive capacity of cytokine‐induced MDSC by ≥70%. We next examined the impact of VDR deletion on the development of tumor MDSC function in MDSC subtypes (M‐ and G‐) isolated from RM‐1 tumors of WT and VDR KO mice. As others have reported, the T cell suppressive function of WT M‐MDSC was 4× greater than G‐MDSC. T cell suppression mediated by M‐MDSC from VDR KO mice was 1.5‐fold higher than that seen in WT M‐MDSC while VDR KO G‐MDSC were 4‐fold more active than WT G‐MDSC. This suggests signaling through the VDR suppresses tumor MDSC function. However, treating mature, tumor MDSC with 1,25(OH)2D (10 nM, 18 h) did not alter T cell suppressive function despite the induction of VDR and CYP24A1 mRNA. Collectively, this suggests that the primary impact of 1,25(OH)2D is on MDSC development. The major finding of the present study is that MDSC are novel targets of 1,25(OH)2D. This 1,25(OH)2D effect decreases their immunosuppressive capability in an early stage of development and expression of VDR throughout their development attenuates the immunosuppressive capabilities of MDSC that are recruited to the tumor microenvironment. This suggests that vitamin D could modulate MDSC function and aid the immune system in attacking and clearing tumor cells.

Support or Funding Information

Lynn Fellowship, Dr. Mary Fuqua Scholarship
Vitamin D Derived from Dietary Whole Egg is more Effective than Supplemental Vitamin D3 in Maintaining Vitamin D Balance in Type 2 Diabetic Rats
Authors: Saande Cassondra J. , Reed Carter H. , Coonts Caitlyn A. , Hahn Kaylee E. , Rowling Matthew J. , Schalinske Kevin L.
Published: November 2023

Vitamin D deficiency is characteristic of type 2 diabetes (T2D) due to urinary excretion of 25‐OH vitamin D3 (25D), the major circulating form of vitamin D that is reflective of vitamin D status. We have previously shown that whole eggs, a rich dietary source of vitamin D, can increase circulating 25D concentrations in T2D rats. Thus, the aim of this study was to compare vitamin D derived from consuming whole eggs versus a dietary supplement of vitamin D3 (i.e. cholecalciferol) in T2D. Zucker diabetic fatty rats (ZDF) (n=24) and their lean controls (n=24) were randomly assigned to one of three diets: an AIN93 casein‐based diet, a whole egg‐based diet, or an AIN93 casein‐based diet containing supplemental vitamin D3 at the same level of total vitamin D provided by the whole egg (37.6 μg/kg diet). Protein was provided at 20% (w/w) of the diet by either casein or whole egg. All diets were matched for lipid content (18.3%) via the addition of corn oil to the casein‐based diets to account for the additional lipid contribution of the whole egg. All rats were placed on their respective diets for 8 weeks. Mean values from all analyses were compared using a one‐way ANOVA (P<0.05). As expected, casein‐fed ZDF rats gained more weight than all of the lean rats; however, ZDF rats fed a whole egg‐based diet exhibited an 18% decrease in weight gain compared to the ZDF‐casein groups. Although ZDF rats fed the whole egg‐based diet gained less weight than ZDF rats fed the casein‐based diets, food intake did not differ within a given genotype. As expected, ZDF rats fed the casein‐based diet had lower (21%) serum 25D concentrations than their lean casein‐fed counterparts. An egg‐based diet fed to the ZDF rats was highly effective at increasing serum 25D concentrations by 130% compared to casein‐fed ZDF rats. In contrast, supplemental vitamin D3 also increased circulating 25D concentrations in the ZDF rats fed casein, but only by 35%. Likewise, serum 25D concentrations of lean rats fed the supplemental vitamin D3 diet and the whole egg‐based diet were increased by 19% and 113%, respectively, compared to lean rats fed the casein‐based diet. These data demonstrate that, at an equal dietary vitamin D concentration, whole egg consumption was markedly more effective at maintaining serum 25D concentrations than supplemental vitamin D3 in both the lean and ZDF genotype.

Support or Funding Information

Egg Nutrition Center, Park Ridge, IL
Is the consumption of foods passing reformulation standards associated with the HEI‐2010?
Authors: Masset Gabriel , Mainardi Fabio , Gressier Mathilde
Published: November 2023

Background

Reformulation of foods and beverages may help to improve the US population dietary intakes. Food nutrient profiling can be used to define reformulation standards for manufacturers.

Objective

This study assessed the association between the consumption of foods passing the Nestlé reformulation standards and the HEI‐2010 and its components.

Methods

Dietary intakes of 5076 participants aged 18+ years were derived from the first 24hr‐recall of the NHANES 2011–12 survey. All foods declared to be consumed were tested against the criteria of the Nestlé Nutritional Profiling System (NNPS) using the RACC serving size, with three outcomes: Pass (i.e. all criteria were met), Fail, and ‘Out‐of‐scope’ for reformulation (e.g. pure frozen fruit). The consumption of Pass, Fail, and Out‐of‐scope foods and beverages was assessed as percentage of total energy, excluding alcoholic drinks. The HEI‐2010 and its components was calculated using the USDA FPED 2011–12 files, and associations with the consumption of NNPS Pass/Fail/Out‐of‐scope products were estimated.

Results

The adult population of the NHANES 2011–12 derived 34.0% (95% CI 33.0;35.0) of its energy from NNPS Pass products, 53.9% (52.6;55.2) from NNPS Fail products, and 12.1% (11.3;12.8) from out‐of‐scope products. The average HEI‐2010 was 51.5 (50.5;52.5). Consumption of both NNPS Pass and Out‐of‐scope products was positively associated with the HEI‐2010; consumption of NNPS Fail products was negatively associated with the HEI‐2010 (Figure). In all cases, trends were highly significant. Consumption of NNPS Pass products was positively associated with the total fruit, whole grains, and empty calories components of the HEI‐2010; and negatively with the dairy, fatty acids, seafood and plant proteins, and whole fruit components. Associations were reversed for the consumption of NNPS Fail foods, which was also negatively associated with the sodium, refined grains, and total vegetables components.

Conclusion

In US adults, the consumption of manufactured foods accounted for the majority of energy intake. Greater consumptions of non‐processed or minimally processed foods was positively associated with the HEI‐2010. Nonetheless, setting manufacturing standards could be a strategy to increase diet quality as highlighted by the positive association between NNPS Pass products and the HEI‐2010. Further research ought to explore whether higher consumption of foods meeting specific reformulation guidelines would encourage a higher nutritional adequacy beyond compliance with food based dietary guidelines.

Support or Funding Information

This study was funded by Nestec SA.
Obesity Is Associated With Increased Expression of Very Low Density Lipoprotein Receptor in Adipose Tissue: A Possible Link to Increased VLDL Catabolism and Adiposity
Authors: Hajri Tahar , Johnson Brian , Talishinskiy Toghrul , Mazpule George , Ewing Douglas , Eld Sebastian , Novack Richard , Schmidt Hans
Published: November 2023

BACKGROUND

Very‐low density lipoprotein receptor (VLDLR) is a member of the low‐density lipoprotein receptor family highly expressed in adipose tissue. It binds a variety of ligands including apolipoprotein E‐containing triglyceride‐rich lipoproteins, and plays a significant role in the catabolism of triglyceride‐rich lipoproteins. The role of VLDLR had been demonstrated in cell culture and animal models, but little is known about its regulation in human. The objective of this study was to assess the impact of obesity on VLDLR expression in adipose tissue, and to evaluate the role of VLDLR in human adipocyte differentiation and lipid deposition.

SUBJECTS AND SAMPLES

Paired subcutaneous and visceral adipose tissue aliquots, as well as blood samples, were obtained from a total of 76 subjects, 16 lean (body mass index: BMI ≤ 24.9 kg/m2), 18 overweight (25 ≤ BMI ≤ 29.9 kg/m2) and 42 obese and morbid obese (BMI ≥ 30 kg/m2) subjects. Concentration of plasma lipids (triglycerides, free fatty acids and cholesterol) and glucose was measured enzymatically. Blood insulin level was assayed by enzyme‐linked immunosorbent assay, and homeostasis model assessment of insulin resistance (HOMA‐IR) was determined. Adipocyte size was examined in hematoxylin and eosin‐stained sections, and VLDLR expression was analyzed in adipose tissue using Western blotting and RT‐PCR. In addition, VLDLR expression was examined in isolated pre‐adipocytes before differentiation and during differentiation to mature adipocytes.

RESULTS

Compared to lean subjects, VLDLR protein level and mRNA abundance in subcutaneous adipose tissue, was up‐regulated in overweight (+46%) and obese subjects (+119%). Similarly, VLDLR expression was up‐regulated in visceral fat but to lesser extent than subcutaneous fat. The abundance of VLDLR mRNA in subcutaneous adipose tissue was positively (p < 0.05) associated with BMI and HOMA‐IR, but not with blood lipids. In addition, VLDLR expression in subcutaneous fat was significantly (p<0.05) associated with increased adipocyte size and triglyceride content. In pre‐adipocytes, VLDLR protein level was virtually inexistent, but increased gradually during differentiation to reach a maximum level in mature adipocytes. Moreover, induction of VLDLR expression in differentiated adipocytes was associated with increased deposition of triglycerides derived mainly from VLDL.

CONCLUSION

The study indicates that obesity up‐regulates VLDLR expression in adipose tissue, and that induction of VLDLR expression during pre‐adipocyte differentiation is associated with increased lipid deposition suggesting a possible role of VLDLR in adipose tissue expansion in human.

Support or Funding Information

Hackensack University Medical Center
Lipocalin‐2 Is Required for Retinoic Acid‐Induced Beiging of White Adipocytes and Insulin‐Stimulated Plasma Membrane Localization of RAR‐α
Authors: Deis Jessica , Guo Hong , Bernlohr David , Chen Xiaoli
Published: November 2023

Beiging of white adipose tissue (WAT) has therapeutic value for treating obesity and metabolic disease. Lipocalin‐2 (Lcn2) is a protein secreted from adipose tissue that is necessary for cold adaptation and non‐adrenergic activation of brown adipose tissue. In this study, we sought to determine whether and how Lcn2 regulates beiging of WAT. Lcn2−/− inguinal adipocytes have impaired p38 mitogen‐activated protein kinase (p38MAPK) signaling and thermogenic gene expression in response to insulin. This is accompanied by mitochondrial dysfunction as shown by significantly reduced basal/maximal respiration, proton leak, and NAD+/NADH ratio. Hormone sensitive lipase and p38MAPK signaling in response to norepinephrine is normal in Lcn2−/− inguinal adipocytes, suggesting Lcn2 promotes thermogenesis by a non‐adrenergic mechanism. Recruitment of beige adipocytes by rosiglitazone treatment during the entire differentiation period results in similar levels of uncoupling protein‐1 (UCP‐1) in wild‐type (WT) and Lcn2−/− inguinal adipocytes. However, retinoic acid (RA) induction of thermogenic genes and UCP‐1 protein is attenuated in rosiglitazone‐treated Lcn2−/− inguinal adipocytes and chronic treatment of mice with retinoic acid resulted in lower UCP‐1 protein levels in inguinal WAT of Lcn2−/− mice when compared to WT. Further, the synergistic effect of insulin and RA on UCP‐1 and peroxisome proliferator‐activated receptor gamma coactivator 1α (PGC‐1α) expression is markedly reduced in Lcn2−/− inguinal adipocytes. Short‐term RA treatment is able to phosphorylate p38MAPK, and this is blunted in Lcn2−/− inguinal adipocytes. We found that retinoic acid receptor‐α (RAR‐α) and Lcn2 are present in the plasma membrane fraction of adipocytes isolated from inguinal and brown adipocytes, suggesting a possible mechanism for rapid phosphorylation of p38MAPK by non‐genomic RAR‐α activation. Interestingly, insulin treatment increased RAR‐α levels to a greater extent than RA in the plasma membrane of WT adipocytes, and this effect was not seen in Lcn2−/− adipocytes. Taken together, our data suggests a model where Lcn2 regulates RA‐induced activation of beige adipocytes through modulating insulin‐stimulated plasma membrane translocation of RAR‐α and non‐genomic action of RAR‐α on phosphorylation of p38MAPK.

Support or Funding Information

This study was supported by the NIDDK‐funded Minnesota Obesity Center (P30DK050456), and NIDDK‐funded traineeship (T32DK083250) to J.D.
Raspberry intake reduces skeletal muscle lipid accumulation and improves insulin sensitivity in mice fed high fat diet
Authors: Du Min , Zou Tiande , Wang Bo , Liang Xingwei , Zhu Mei‐Jun
Published: November 2023

Introduction

Polyphenolics promote adipose tissue browning and increase lipid oxidation, but their roles in skeletal muscle intracellular lipid accumulation and insulin resistance is unclear. Raspberry contains rich polyphenolic compounds.

Objective

To test the protective role of dietary raspberry on lipid accumulation and insulin sensitivity in skeletal muscle of mice fed a high fat diet (HFD).

Methods

Wild‐type male mice were randomly separated into 4 groups and fed with a control diet (CON) or a high fat diet (HFD, 60% energy as fat mimicking the common high energy, high fat diet in western societies) supplemented with 0 or 5% freeze dried raspberry (RAS) for 12 weeks.

Results

There was insulin resistance in mice fed with HFD without raspberry, as indicated by increased muscle triglyceride content and attenuated insulin signaling; these adverse changes were ameliorated by raspberry supplementation. In addition, inflammation was detected in the skeletal muscle of HFD mice, as shown by the enhanced expression of tumor necrosis factor α (TNFα), interleukin‐6 (IL‐6) and IL‐1β, as well as the increased phosphorylation of p65, a key mediator of inflammatory nuclear factor (NF)‐κB signaling, which was inhibited due to raspberry consumption.

Conclusion

Raspberry intake improved insulin resistance and suppressed inflammation in skeletal muscle of mice consuming HFD mimicking the popular western high energy diet.

Support or Funding Information

Supported by National Processed Raspberry Council
Association of Supplemental Nutrition Assistance Program Participation with Social Cohesion and Financial Worry based on Race and Ethnicity among U.S. Adults
Authors: Burke Michael P , Frongillo Edward A
Published: November 2023

The Supplemental Nutrition Assistance Program (SNAP) is the largest federal nutrition assistance program in the U.S. Besides sociodemographic factors, however, little is known about what predicts SNAP participation. Given that SNAP increases food security and access to healthy food, it is critical to understand factors that predict its use. This study examined how social cohesion and financial worry predict SNAP participation, and how the prediction differs by race and ethnicity.

Data were from the 2013–2015 waves of the National Health Interview Survey (NHIS). We restricted the analytic sample to households with incomes less than 200% of the federal poverty guidelines (n=27,582). We constructed a social cohesion scale (range: 0–12) that summed four Likert‐type items related to: getting help from neighbors, living in a close‐knit community, counting on neighbors, and trusting neighbors. We also constructed a financial worry scale (range: 0–18) that summed six Likert‐type items measuring financial worry about: retirement, standard of living, healthcare costs, medical accidents, paying bills, and housing costs. Higher scores on each index indicate higher social cohesion or financial worry. Multiple‐variable logistic regression was used to test the association between SNAP participation, social cohesion, and financial worry, accounting for NHIS complex survey sampling and adjusted for sociodemographic factors, household food security status, neighborhood tenure, home ownership status and self‐perceived health status.

Thirty‐seven percent of respondents reported SNAP participation in the last 12 months. The mean social cohesion score was 7.48 (± 0.04) and the mean financial worry score was 8.80 (± 0.06). Each 1‐unit increase in social cohesion was associated with 0.97 times the odds of SNAP participation (95% CI: 0.96–0.98). The association between financial worry and SNAP participation was modified by race and ethnicity (P<0.001). Among African‐Americans, SNAP participation was not associated with financial worry. Among Hispanics, SNAP participation was lower with higher financial worry. Among whites and other races, SNAP participation was higher with higher financial worry.

Financial worry and social cohesion are two independent predictors of SNAP participation among US adults. Furthermore, financial worry differentially predicted SNAP participation based on race and ethnicity. Research is needed to understand why higher social cohesion predicts lower SNAP participation and why financial worry differentially predicts SNAP participation based on race and ethnicity.

Support or Funding Information

The views expressed in this abstract are those of the authors and do not represent the U.S. Department of Agriculture, Food and Nutrition Service. The authors have no source of research support to disclose.
Lead exposure, dietary magnesium and glucose homeostasis in Chinese adults
Authors: Mendez Michelle A. , Liu Liping , Du Shufa , Wang Huijun
Published: November 2023

Background

There is mounting evidence that pollutants, including toxic metals, contribute to the global epidemic of diabetes. Along with laboratory data suggesting that lead (Pb) exposure may disrupt insulin secretion and promote glucose intolerance, a handful of epidemiological studies have reported associations between Pb and poor glucose homeostasis. A growing literature also suggests that nutrients such as dietary magnesium (Mg)—an essential metal critical for insulin action—may delay the progression of impaired glucose regulation. Our aim was to evaluate whether this beneficial dietary metal may help to reduce the impaired glucose regulation associated with toxic metals such as Pb.

Methods

We used a subsample of more than 4000 adults aged 18–65y who provided fasting serum and toenail samples in the 2009 wave of the China Health and Nutrition Survey. We measured Pb concentrations in toenail samples using inductively coupled plasma mass spectroscopy (ICP‐MS), and measured fasting glucose using colorimetric assay methods. Dietary Mg intake was estimated from three days or 24‐h dietary recalls. We estimated the association between toenail Pb concentrations and fasting glucose levels using multivariable linear regression adjusting for age, gender, body mass index, waist circumference, physical activity, urbanicity, education level, toenail arsenic and selenium, and intakes of energy, meat and rice. Interactions with dietary Mg were examined using tertiles of intake.

Results

The median (interquartile range) toenail Pb concentration was 1.15 (1.45) mg/kg, and the mean (SD) Mg intake was 296 (107) mg/dL. The mean fasting serum glucose level was 95.8 (24.7) mg/dL. After multivariable adjustment, among individuals in the lowest tertile of dietary Mg, there was a significant increase in fasting glucose associated with a 1‐unit increase in log‐transformed toenail Pb (β±SE 0.64±0.27 mg/dL, P<0.05). However, among individuals in the highest intake tertile, toenail Pb was associated with a non‐significant reduction in fasting glucose (β±SE −0.34±0.28 mg/dL NS; interaction P<0.05).

Conclusion

Findings suggest that exposure to Pb may promote impaired glucose homeostasis, and that dietary Mg may help to reduce the diabetogenic effects of Pb exposure. Further research is needed to determine whether essential metals such as Mg may help to mitigate the risk of diabetes associated with toxic metals such as Pb.

Support or Funding Information

This research uses data from the China Health and Nutrition Survey, funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)(R01‐HD30880). We also are grateful to the Carolina Population Center (R24 HD050924) for general support.
Dietary Sialyllactose Influences Magnetic Resonance Imaging Outcomes in the Piglet Corpus Callosum
Authors: Mudd Austin T , Fleming Stephen A , Chichlowski Maciej , Berg Brian M , Donovan Sharon M , Dilger Ryan N
Published: November 2023

Sialyllactose is a milk oligosaccharide composed of a sialic acid conjugated to a lactose molecule that is present in human, bovine and porcine milks. Animal studies have demonstrated a variety of biological effects associated with provision of dietary sialyllactose, including gut maturation, immune function and increasing brain sialic acid levels. This study aimed to examine the dose response effects of sialyllactose (Lacprodan SAL‐10®; SL) on piglet brain development. Beginning at 2 d of age, 38 (n = 9–10 per treatment) vaginally‐derived male piglets received one of four diets formulated to contain: control (CONT) [0 mg SL/L milk replacer], low (LOW) [130 mg SL/L], moderate (MOD) [380 mg SL/L], and high (HIGH) [760 mg SL/L]. All diets contained 4 g/L of a 1:1 mixture of polydextrose and galactooligosaccharides. At 32 or 33 d of age, piglets were subjected to magnetic resonance imaging (MRI) procedures to assess macrostructural and microstructural brain development. All outcomes were analyzed using a one‐way ANOVA to assess differences between dietary treatments, significant outcomes were accepted at P ≤ 0.05 and trends at 0.05 < P < 0.10. Absolute brain volumes were not different (P > 0.05) between dietary treatments. Moreover, assessment of ten individual brain regions did not yield differences (P > 0.05) due to diet in absolute or relative volume measures. Axial, mean and radial diffusivity are used to assess white matter integrity and have been shown to change with age. We measured changes in these variables in different brain regions associated with feeding different levels of dietary SL. Diffusion tensor imaging revealed differences due to dietary treatment in measures of axial diffusivity (P = 0.002), mean diffusivity (P = 0.004), and radial diffusivity (P = 0.007) of the corpus callosum. In each of these outcomes, piglets provided the MOD diet exhibited the highest diffusivity measures compared with all other dietary treatments. Mean diffusivity (P = 0.075) and radial diffusivity (P = 0.051) in the left hippocampus tended to differ by dietary treatment, with piglets provided the MOD diet exhibiting the highest diffusivity measures. Recent evidence in piglets suggests provision of SL resulted in increased corpus callosum sialic acid. While the results presented herein do not assess sialic acid concentrations of the corpus callosum, our results corroborate recent evidence suggesting sensitivity of the corpus callosum to provision of dietary SL. The differences in corpus callosum MRI measures in response to dietary SL merit future research to assess the impact of SL on specific aspects of corpus callosum development and associated functions.

Support or Funding Information

This project was supported by Mead Johnson Nutrition.
ZnT2 regulates lysosomal acidification and biogenesis during mammary gland involution
Authors: Rivera Olivia C. , Hennigar Stephen R. , Lee Sooyeon , Kelleher Shannon L.
Published: November 2023

Precocious involution may be an underlying cause of early infant weaning or overt lactation failure. The initial phase of mammary gland (MG) involution is characterized by lysosomal‐mediated cell death (LCD), which requires extensive upregulation of lysosomal biogenesis, acidification and activity. We recently showed that in response to the pro‐involution signal TNFα, the zinc transporter ZnT2 traffics from secretory vesicles to lysosomes, is critical for lysosome biogenesis, and is associated with LCD and activation of MG involution. Moreover, obesity‐induced inflammation is also associated with ZnT2 and zinc accumulation in lysosomes, and the promotion of LCD and precocious involution. However, the role of ZnT2 in LCD is currently not understood. We hypothesized that ZnT2 modulates proton transport, mediating lysosomal biogenesis, acidification, and activity, thereby driving proper execution of MG involution. Histology of involuting MGs from ZnT2‐null mice (ZnT2ko) had reduced alveolar regression, more closely resembling a lactating MG than that of involuting MGs from their wild‐type (wt) littermates. The MG area repopulated by adipocytes only increased by 12% in ZnT2ko mice compared to a 37% increase in wt mice (P<0.001). Furthermore, activation of the involution marker Stat3 was significantly reduced in ZnT2ko involuting MGs (P<0.05), indicating insufficient involution. Co‐immunoprecipitation studies of ZnT2 and the vacuolar ATPase (v‐ATPase) proton transporter in cultured mammary epithelial cells (MECs) revealed that ZnT2 interacts with both the cytoplasmic (V1) and membrane‐embedded (V0) subunits of v‐ATPase, suggesting a role for ZnT2 in v‐ATPase assembly and proton transport. Consistent with this finding, ZnT2 over‐expression in MECs significantly increased the number, size and acidification of lysosomes, while ZnT2‐attenuated MECs were not able to undergo lysosome biogenesis or acidification. Immunofluorescent imaging revealed that lysosomal abundance of V1 was reduced by ~75% (P<0.01) which was associated with a significant decrease in lysosome abundance (P<0.001) and size (P<0.01) in the involuting MGs of ZnT2ko mice compared to wt mice, suggesting impaired lysosomal biogenesis. Our results establish ZnT2 as a critical regulator of v‐ATPase activity and lysosomal acidification, which is essential for the activation of involution. Given the identification of numerous mutations and non‐synonymous genetic variants in ZnT2 that result in impaired ZnT2 function and breast dysfunction, these findings suggest that genetic variants in ZnT2 may modulate lysosome biogenesis and activity, thereby affecting lactation duration.

Support or Funding Information

Intramural Funds from Penn State Hershey College of Medicine, Department of Surgery
In Vitro Supplementation of Leucine Increases Murine HC11 Cell Proliferation
Authors: McGuckin Molly Mae , Suryawan Agus , Davis Teresa A , Peterson Daniel G , Manjarin Rodrigo
Published: November 2023

Mammary tissue undergoes multiples cycles of cell growth and proliferation during the lifetime of the female to meet the nutrient demand of the suckling neonate. On the basis of studies in rodents, pigs and humans demonstrating the anabolic effects of leucine (Leu) through the activation of mammalian target of rapamycin (mTOR) signaling pathway, there has been recent interest in the potential of supplementary Leu to improve skeletal muscle protein synthesis and overall nitrogen retention. To determine whether Leu supplementation also upregulates mTOR pathway in mammary tissue and increases mammary cell proliferation, a murine mammary cell line (HC11) was cultured in different concentrations of Leu (0, 1, and 2 mM). Cell proliferation was measured using flow cytometry at 0, 8, and 16 days. Reverse transcription quantitative PCR was performed to measure mRNA abundance of mammary Leu transporter LAT1 (SLC7A5), the intracellular Leu sensor for the mTOR signaling pathway leucyl‐tRNA synthetase (LARS2), mTOR and its downstream effector ribosomal protein S6 kinase (RPS6K1), and cyclin D (CCND1), a marker for cell proliferation. Guanine phosphoribosyl transferase (HPRT), RNA polymerase 3 (POL3), and ribosomal protein L3a (RPL3a) were used as reference genes. Statistical analysis was performed by ANOVA using a linear mixed model to account for treatment and replication effects. After 16 d cell proliferation increased in response to 1 mM Leu compared to 0 mM (P < 0.05), and increased further (P < 0.05) in cells supplemented with 2 mM Leu. Gene expression of SLC7A5, LARS2, mTOR, RPS6K1, and CCND1 did not differ between groups. Taken together, these results suggest that Leu supplementation increases mammary cell proliferation in vitro, but this effect is not associated with an increase in mRNA abundance of aforementioned genes. Further work is needed to elucidate the mechanisms by which dietary Leu supplementation increases mammary cell proliferation, as it may hold the potential to enhance mammary growth and subsequent milk production in animals.

Support or Funding Information

ARI 58982