bluuebunny/crossref_metadata_2025 huggingface dataset:
Pre‐Meal Television Viewing and Exercise on Subjective Appetite and Food Intake in Children
Authors: de Zepetnek Julia O Totosy , Da Silva Melissa , Miller Kerry , Bellissimo Nick
Published: November 2023

Purpose

The effects of pre‐meal television viewing (TVV) and exercise (EXR) on subjective appetite and food intake (FI) regulation are not well understood in the paediatric population. The objective of the present study was to investigate separate and concurrent effects of 30‐min TVV and moderate‐intensity EXR immediately before mealtime on subjective appetite and FI in 9 to 14 year old boys and girls.

Methods

During four test mornings one week apart and 2 h after a standardized breakfast, 13 children (n=7 boys, n=6 girls; age 11.1 ± 0.5 years) were randomly assigned to one of four 30‐min treatment conditions: TVV only, EXR only, TVV and EXR, and sitting control. Immediately following the treatment, FI was measured via an ad libitum pizza meal. Subjective appetite was assessed at baseline, 15 and 30‐min during the treatment condition, and upon trial completion at 60‐min. Subjective emotions were assessed at baseline and at 30 min.

Results

FI and water intake were not affected by treatment condition, but after subtracting exercise energy expenditure (EE), there was a main effect of the exercise on FI (p=0.01), which lead to an average ~20% reduction in FI compared to the sedentary conditions (TVV and control). Thirst scores were higher in the exercise vs. sedentary groups at 15‐min (p<0.01) and 30‐min (p<0.001). Subjective average appetite and emotion were not affected by treatment, but increased with time in all conditions (p<0.0001 and p<0.0001, respectively).

Conclusions

Exposure to 30‐min TVV and EXR before eating did not affect subjective emotions, subjective appetite, or FI. TVV alone or concurrent with EXR did not influence FI regulation, suggesting that physiologic signals of satiation and satiety are not overridden by environmental stimuli of pre‐meal screen‐time exposure among young children. Increased EE did not result in compensatory increases in short‐term FI, resulting in a decreased net energy balance during the measurement period. Therefore, moderate‐intensity exercise leading to increased EE, independent of TVV, influences energy balance and may support achieving or maintaining healthy weights in children.

Support or Funding Information

Faculty of Community Services Seed Grant (Nick Bellissimo), and the Undergraduate Research Award (Melissa Da Silva).
Are You What Your Mother Ate: Maternal Artificially‐Sweetened Beverages Intake During Pregnancy and Offspring Growth and Obesity Through Age 7 Years?
Authors: Zhu Yeyi , Olsen Sjurdur F , Mendola Pauline , Halldorsson Thorhallur I , Rawal Shristi , Hinkle Stefanie N , Yeung Edwina H , Chavarro Jorge E , Grunnet Louise G , Granström Charlotta , Bjerregaard Anne Ahrendt , Hu Frank B , Zhang Cuilin
Published: November 2023

Background

Artificial‐sweeteners are widely replacing caloric sweeteners, but emerging experimental data have linked them to metabolic perturbations. Epidemiologic data on long‐term intergenerational impact of artificially‐sweetened beverage (ASB) consumption during pregnancy on offspring obesity risk are lacking. We prospectively investigated intake of ASBs and sugar‐sweetened beverages (SSBs) during pregnancy in relation to offspring growth through age 7 years among high‐risk children born to women with gestational diabetes, serving as a unique model to study early origins of obesity.

Methods

In a prospective study of 918 mother‐singleton child dyads from the Danish National Birth Cohort, maternal dietary intake was assessed by a food frequency questionnaire during pregnancy. Offspring body mass index z‐scores (BMIZ) and overweight/obesity status were derived using weight and length/height measured at birth, 5 and 12 months, and 7 years. Linear regression and Poisson regression with robust standard errors were used, adjusting for major maternal and offspring risk factors.

Results

Approximately half of women reported consuming ASBs during pregnancy and 9% consumed daily. Compared to never consumption, daily ASB intake during pregnancy was positively associated with offspring large‐for‐gestational age [adjusted relative risk (aRR) 1.57; 95% CI: 1.05, 2.35], and BMIZ (adjusted β 0.59; 95% CI: 0.23, 0.96) and overweight/obesity (aRR 1.93; 95% CI; 1.24, 3.01) at 7 years. Further, per‐serving‐per‐day substitution of ASBs with water during pregnancy was related to a significantly lower risk of overweight/obesity at 7 years (aRR 0.83; 95% CI: 0.76, 0.91), whereas SSB substitution with ASBs was not related to a lower risk (aRR 1.14; 95% CI: 1.00, 1.31).

Conclusions

We observed positive associations between intrauterine exposure to ASBs and birth size and risk of overweight/obesity at 7 years. Findings further raise the questionability of promoting ASBs as “healthier” alternatives for SSBs, particularly among high‐risk pregnant women. Future studies with longer follow up beyond early childhood are warranted.

Support or Funding Information

The study is funded by the Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (contract # HHSN275201000020C). The DNBC is supported by grants from The Danish Research Council # 09‐067124 (Center for Fetal Programming) and 09‐075611.
Plasma Alpha‐Linolenic and Linoleic Acids in Early Pregnancy are Associated with Birth Outcomes in Rural Malawi
Authors: Oaks Brietta M. , Dewey Kathryn G. , Maleta Kenneth , Sadalaki John R. , Ashorn Ulla , Harris William S. , Ashorn Per
Published: November 2023

Background

Several studies suggest that low circulating levels of long‐chain omega‐3 fatty acids are associated with poor birth outcomes, however results are mixed possibly because the majority of studies have been conducted in high‐income settings.

Objective

To determine whether fatty acid status during pregnancy is associated with birth outcomes in Malawian women.

Methods

We performed a nested cohort study (n=315) of pregnant women ≤ 20 wk gestation enrolled in a large randomized controlled trial in rural Malawi. We measured plasma fatty acids (wt%) at enrollment and at 36 wk gestation. Specific fatty acids of interest included the omega‐3 fatty acids, alpha‐linolenic acid (ALA) and docosahexaenoic acid (DHA); and the omega‐6 fatty acids, linoleic acid (LA) and arachidonic acid (AA). Study nurses recorded birth size, and duration of gestation was estimated by baseline ultrasound. Linear regression and logistic regression models were used to examine the association between plasma fatty acids and birth outcomes.

Results

In adjusted analyses, higher plasma ALA at ≤ 20 wk gestation was associated with a longer duration of gestation (β: 0.34 d/0.1%, SE: 0.22, p=0.03), greater birth weight (β: 16 g/0.1%, SE: 6.4, p=0.01), and greater head‐circumference‐for‐age z‐score (β: 0.03 SD/0.1%, SE: 0.01, p=0.04). Above median plasma ALA at ≤ 20 wk gestation was associated with a lower risk of newborn stunting (RR: 0.53, 95% CI: 0.30, 0.94, p=0.03) versus below median. Plasma ALA at 36 wk gestation was not associated with any birth outcome. Higher LA at ≤ 20 wk gestation was associated with greater weight‐for‐age (WAZ), and higher LA at 36 wk gestation with greater WAZ and head‐circumference‐for‐age z‐score. AA and DHA levels were not associated with any birth outcome.

Conclusion

Higher plasma ALA and LA in early pregnancy were associated with better birth outcomes, however their longer‐chain metabolites AA and DHA were not.

Support or Funding Information

Funding was provided by a grant to UC Davis by The Bill & Melinda Gates Foundation.
Iron Absorption from Iron‐enriched Aspergillus oryzae is Similar to Ferrous Sulfate in Humans
Authors: Reddy Manju B. , Armah Seth M. , Stewart Jeanne , Bian Yilin , Bries Amanda , O'Brien Kimberly O.
Published: November 2023

Iron deficiency anemia is the most common nutritional disorder in infants, children and young women – particularly in developing countries. Due to the problems associated with inorganic iron both as a supplement and fortificant, significant efforts have been made in finding effective alternatives. Though fortification is a sustainable strategy in reducing the incidence of anemia, challenges arise as highly absorbable iron compounds can cause undesirable sensory changes to the food matrix, whereas those iron compounds resulting in fewer sensory changes have low absorption. Our objective was to compare iron absorption from iron‐enriched Aspergillus oryzae, AspironTM, (ASP) with ferrous sulfate by using stable isotope methodology in humans. ASP is a natural free‐flowing powder of inactive fungal biomass containing 6–8% elemental iron produced by Cura Global Health, Inc. using a proprietary technology. ASP was intrinsically labelled by growing it in iron‐enriched media containing 58FeSO4 and the ferrous sulfate was labeled with 57Fe. Sixteen female subjects (18–35 y), non‐pregnant and non‐anemic with ferritin concentration of <40ug/L were recruited in this study. Subjects were randomized to consume test meals (semi‐purified meal that was used in several earlier studies) with stable iron isotopes on two consecutive days. Each meal contained 10 mg iron as 57FeSO4 form or 2 mg 58Fe plus 8 mg natural abundance iron in ASP form. At the beginning of the study, C‐reactive protein, hepcidin, and ferritin concentrations were measured. Iron absorption was assessed by measuring isotope enrichment in blood after 14 days of feeding. The 12% difference in absorption between 57Fe (17.18 ± 14.2%) and 58Fe (15.14 ± 12.3%) was not statistically significant. Iron absorption from both ferrous sulfate and ASP was inversely correlated with serum ferritin (R2 =0.53, p<0.002; R2=0.58, p<0.0005, respectively) as well as with hepcidin (R2=0.30, p<0.05; R2=0.31, p<0.05, respectively) suggesting that the absorption of ASP is regulated similarly to ferrous sulfate. In conclusion, ASP has the potential to be used as a fortificant, which can offer high bioavailability and may cause less organoleptic changes due to its limited solubility. Future studies are needed to assess its effectiveness in high phytate and high polyphenol containing meals.

Support or Funding Information

Cura Global Health, Inc. Ames, IA
Differential Regulation Of Transcriptional Factors Of Selenoprotein Genes By Moderately High Dietary Concentrations Of Se And Fat In Liver And Adipose Tissue Of Wildtype And Gpx1−/− Mice
Authors: Zhao Zeping , Zhou Jichang , Lei Xin Gen
Published: November 2023

Our previous research demonstrated striking differences in regulations of selenoprotein gene mRNA between in the liver and adipose tissue of wild‐type (WT) and Gpx1−/− male mice (2–4 months of age) by moderately high dietary concentrations of Se (1.0 vs. 0.3 mg/kg as selenite) and/or high fat (25 vs. 5% as lard). This study was followed up to explore if there was an underlying transcriptional mechanism for those differential regulations. Initially, we submitted the promoter region sequences (−2000bp to 0bp) of all the affected selenoprotein genes by the high fat and Se diets to TRANSFAC database and identified 7 common transcription factors (TF): C/ebpβ, Yy1, Hoxa5, Gr, Hes1, Nf1 and Myod. Subsequently, we determined responses of mRNA abundances of these TF to the high fat and Se diets in the liver and adipose tissue samples collected from the previous experiment (total = 40 mice, n = 5/diet by age and genotype). In the adipose tissue of the WT mice, mRNA levels of all 7 TF were consistently down‐regulated (P < 0.05) by the high Se and fat diets. In contrast, the high fat diet enhanced (P < 0.05) Myod and Hes1 and suppressed (P < 0.05) only Hoxa5 and Nf1 mRNA, while the high Se diet enhanced (P < 0.05) only C/ebpβ and Gr mRNA in the liver of WT mice. Knockout of Gpx1 allowed both positive and negative effects (P < 0.05) of the high Se and fat diets on the mRNA levels of these TF in the liver and adipose tissue, but the overall regulation seemed to be intensified in the liver and attenuated in the adipose tissue compared with those in the WT mice. Correlation analysis revealed strong positive relationships (R2 > 0.8, P < 0.05) between mRNA of each of the 7 TF with 9 selenoproteins (Gpx4, Gpx6, Selh, Seli, Selk, Selm, Selo, SELP, Sels and Selv) in the adipose of WT mice. However, such correlations were shown between only 5 selenoprotein genes (Dio2, Dio3, GPX3, Gpx6 and Sep15) and 3 TF (Myod, Hes1 and Gr) in the liver of WT mice. Likewise, knockout of Gpx1 removed many of these correlations in the liver or adipose tissue and rendered 3 negative correlations (P < 0.05) between Gr and Dio1 and between Nf1/Yy1 and Gpx4 in the adipose tissue. In conclusion, the differential regulations of selenoprotein gene expression in the two tissues of two genotypes by the moderately high dietary intakes of Se and fat might be mediated by their impacts on the expression of the TF having binding domains in the promoters of these genes.

Support or Funding Information

NIH DK 53018.
Dietary Selenium Deprivation Oppositely Impacts Longevity and Healthspan in Telomere Dysfunctional Mice
Authors: Cheng Wen‐Hsing , Wu Ryan T , Cao Lei , Witwer Kenneth W , Lu Hsin‐Yi
Published: November 2023

Selenium (Se), a trace metalloid essential for life, plays nutritional and physiological roles mainly through selenoproteins. While telomere attrition provokes DNA damage response and, subsequently, replicative senescence, such an aging process is restricted in mice due to their intrinsically long telomeres. To circumvent this limitation and employ a mouse model with humanized telomeres, weanling third generation telomerase RNA component knockout mice carrying short telomeres were fed a Se‐deficient, Torula‐yeast basal diet or the diet supplemented with 0.15 ppm Se as sodium selenate throughout their life. Dietary Se deprivation delayed wound healing and accelerated a wide range of age‐related degeneration including osteoporosis, grey hair, alopecia, cataract, and hyperglycemia. Surprisingly, long‐term dietary Se deprivation paradoxically promoted longevity. Plasma microRNA profiling revealed a circulating signature of Se deprivation and aging, and subsequent ontological analyses predicted dominant changes in metabolism. Dietary Se deprivation accelerated age‐dependent declines in glucose tolerance, glucose‐stimulated insulin production and insulin sensitivity, as well as DNA damage and senescence responses in the pancreas. Selenotranscriptomic and metagenomic analyses identified key selenoproteins and gut bacteria in the response to dietary Se deprivation in the mice at 18 and 24 months of age. Altogether, these results suggest a novel model of aging with conceptual advances, whereby Se at low levels may be considered a hormetic chemical and decouple healthspan and longevity.
Chlorogenic Acid Ameliorates Alcoholic Liver Disease through MiRNA‐mediated Restoration of Mitochondrial Redox System
Authors: Kim Hyunjin , Pan Jeong Hoon , Kim Jae Kyeom , Kim Young Jun , Lee Jin Hyup , Park Jeen‐Woo
Published: November 2023

MicroRNAs (miRNA) play essential roles in virtually all cellular and biological processes in liver development, differentiation and homeostasis. Altered expression levels of miRNA were observed in patients with alcoholic liver diseases (ALD) including liver steatosis, cirrhosis and hepatocellular carcinoma. Mitochondria, the main organelles involved in intracellular ROS production, play central roles in modulating redox‐dependent cellular processes, such as metabolism and apoptosis, and disruptions of the mitochondrial redox metabolism are closely associated with ALD. Dietary polyphenols are a versatile group of phytochemicals with many potentially beneficial activities in terms of disease prevention. It is recently reported that the dietary components can selectively activate or inactivate gene expression through epigenetic regulation including alteration in the miRNA expression to exhibit the physiological roles in the prevention of various diseases. In the present study therefore, we investigated if chlorogenic acid (CGA), a potent bioactive polyphenol present in vegetables, can selectively modulate gene expression through miRNA regulation to elicit their beneficial effects. Here we show that CGA protect alcohol‐induced liver injury in mice and these functions of CGA are closely associated with suppression of hepatic apoptosis and inflammation mediated by mitochondrial ROS. Of note, in the global miRNA profiling analysis, hepatic miRNAs were either elevated or suppressed in response to CGA supplementation. Predictions by Ingenuity Pathway Analysis indicated that some of miRNAs target genes are related with hepatic mitochondrial redox metabolism. Moreover, the epigenetic mechanisms are responsible for, at least in part, effects of CGA against the alcoholic liver injury through restoration of the mitochondrial redox system. Taken together, our results highlight the importance of miRNA in the regulation of mitochondrial redox systems and demonstrate that CGA plays a key role in modulating the alcohol‐induced liver injury through miRNA modulation. Further investigations are warranted regarding the net downstream effects of miRNA modulation as pertains to ALD.

Support or Funding Information

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (Grant No. NRF‐2015R1A4A1042271).
Dietary Avicularin Alleviated Type 2 Diabetes in Mice
Authors: Zhu Xiaoai , Ouyang Wen , Miao Jianyin , Xiong Ping , Feng Konglong , Li Minxiong , Cao Yong , Xiao Hang
Published: November 2023

Many dietary flavonoids exist as glycosides in fruits and vegetables, and they are considered as bioactive food components potentially responsible for various health benefits. Type 2 diabetes mellitus is a complex and polygenic disease with increasing global prevalence. In this study, the inhibitory effects of avicularin (quercetin‐3‐O‐α‐arabinofuranoside), a flavonoid glycoside commonly found in apple and mango, were determined in the mice with high fat diet/streptozotocin induced type 2 diabetes. Our results demonstrated that dietary avicularin treatment (100 mg/kg/d) reduced levels of fasting blood glucose, TG and LDL‐C, improved β‐cell function, and suppressed hepatic steatosis in diabetic mice. Gene expression analysis by RNA‐Seq revealed that arachidonic acid metabolism, drug metabolism‐cytochrome P450, drug metabolism‐other enzymes, MAPK signaling pathway, metabolic pathways, metabolism of xenobiotics by cytochrome P450, p53 signaling pathway and retinol metabolism were the major pathways altered in the liver of the diabetic mice in comparison with that of the negative control mice (healthy mice). Within the type 2 diabetes mellitus related pathways, ADIPO, P13K, SOCS, VDCC, SUR1, GK, PYK genes were upregulated in diabetic mice compared to the healthy mice, and avicularin treatment significantly downregulated these genes in the diabetic mice. Within the PPAR pathways, the mRNA levels of FABP1, SCD‐1, SCP‐X, ADIPO, PEPCK were increased in the diabetic mice, and avicularin treatment effectively decreased the levels of these gens in the diabetic mice. Avicularin treatment also upregulated the genes such as CYP7A1, CYP8B1, and CYP4A1 that was downregulated in the diabetic mice in comparison with the healthy mice. Taken together, our results demonstrated the protective effects of avicularin against diabetes and provided a global view of the effects of avicularin on the complexity transcriptome in diabetic mice.

Support or Funding Information

This study was supported by the University of International Cooperation in Science and Technology Innovation Platform Project of Guangdong (2013gjhz0003), the Education Department of Guang zhou Province (Grant No. 2013J4100075), the National Natural Science Foundation of China (Grant No. 31201321).
N‐3 Polyunsaturated Fatty Acids Increase Hepatic Fibroblast Growth Factor 21 Sensitivity Through PPARγ‐β‐klotho Pathway
Authors: Ling Wenhua , Yang Wenqi
Published: November 2023

Objective

Fibroblast growth factor 21 (FGF21) is an important physiological metabolic regulator with diverse functions in lipid and glucose metabolism. However, circulating FGF21 levels were elevated in obesity, nonalcoholic fatty liver disease (NAFLD) and atherosclerosis, which is also demonstrated in our previous study that elevated FGF21 levels were associated with dyslipidemia and insulin resistance. Paradoxically increased FGF21 levels in metabolic disorders indicate impaired FGF21 sensitivity or occurrence of FGF21 resistance. In the present study, we found that FGF21 was involved in fish oil‐mediated hepatic lipid‐regulating and anti‐inflammatory effects in mice fed with high fat diet. However, fish oil supplementation did not significantly increase hepatic and circulating FGF21 protein levels. Whether fish oil feeding‐induced benefits in liver are related to hepatic FGF21 sensitivity remains unclear and needs further investigation.

Methods

To determine the effects of n‐3 polyunsaturated fatty acids (PUFAs) on FGF21 sensitivity, we examined the response to acute FGF21 administration in vivo and in vitro.

Results

Male C57BL/6J mice were fed a low fat diet (LFD), a high fat diet (HFD) or a fish oil supplemented high fat diet (FOD) for 12 weeks. Fish oil improved HFD‐induced hepatic steatosis and inflammation while exerted no obvious effect on FGF21 protein expression. Nevertheless, FGF21 knockout studies demonstrated that FGF21 participated in fish oil‐induced metabolic benefits. Then the FGF21 signaling pathway of n‐3 PUFAs‐induced improvement in lipid metabolism were examined. In vivo and in vitro experiments showed that n‐3 PUFAs, DHA and EPA, promoted hepatic FGF21 signal transduction and enhanced FGF21‐induced changes in serum insulin and NEFA. N‐3 PUFAs‐mediated elevated hepatic FGF21 sensitivity was probably due to increased hepatic β‐klotho expression. Furthermore, PPARγ siRNA knockdown and PPARγ selective antagonist GW9662 treatment blocked the effects of DHA to enhance β‐klotho expression and FGF21 signaling, illustrating that PPARγ participated in DHA‐regulated β‐klotho expression and FGF21 sensitivity.

Conclusion

Our data indicate that n‐3 PUFAs increase hepatic FGF21 sensitivity and β‐klotho expression probably through a PPARγ dependent mechanism, and may thereby exert hepatic beneficial effects on lipid metabolism and inflammation.

Support or Funding Information

This work was supported by grants from the National Research Program of China (973 Program, 2012CB517506).
Different Signaling Patterns Contribute to Loss of Keratinocyte Cohesion Dependent on Autoantibody Profile in Pemphigus
Authors: Walter Elias , Egu Desalegn , Vielmuth Franziska , Rotkopf Lukas , Spindler Volker , Waschke Jens
Published: November 2023

Pemphigus is an autoimmune blistering skin disease. Here, we characterized the mechanisms engaged by pemphigus IgG from patients with different clinical phenotypes and autoantibody profiles. All pemphigus vulgaris (PV) and pemphigus foliaceus (PF) IgG and AK23 caused loss of cell cohesion, cytokeratin retraction and p38MAPK activation. Strong alterations in desmoglein (Dsg) 3 distribution were caused by mucosal (anti‐Dsg3 antibodies), mucocutaneous (anti‐Dsg1 and anti‐Dsg3 antibodies) as well as atypical cutaneous (anti‐Dsg3 antibodies only) PV‐IgG. All PV‐IgG fractions and AK23 compromised Dsg3 but not Dsg1 interactions and enhanced Src activity. In contrast, rapid Ca2+ influx and Erk activation were induced by mucocutaneous PV‐IgG and pemphigus foliaceus (PF) IgG (both containing anti‐Dsg1) whereas cAMP was increased by mucosal and mucocutaneous PV‐IgG only. Selective inhibition of p38MAPK, Src or PKC blocked loss of keratinocyte cohesion in response to all autoantibody fractions whereas Erk inhibition was protective against mucocutaneous PV‐IgG and PF‐IgG only. These results demonstrate that signaling patterns parallel the clinical phenotype. Some mechanisms involved in loss of cell cohesion are caused by antibodies targeting Dsg3 whereas others correlate with autoantibodies against Dsg1. The concept of key desmosome regulators including p38MAPK, PKC and Src may explain why in several experimental models of pemphigus selective inhibition of one of these pathways was protective. Accordingly, in an ex vivo human skin model where mucocutaneous PV‐IgG but not AK23 induced blistering, inhibition of p38MAPK was protective and abolished ultrastructural alterations and reduction of desmosomes.
Novel Role of Lewis A Glycans in Regulating Neutrophil Trafficking
Authors: Brazil Jennifer C , Sumagin Ronen , Lee Goo , Louis Nancy A , Cummings Richard D , Parkos Charles A
Published: November 2023

Pathogen‐triggered neutrophil (PMN) recruitment is critical for innate immunity, but aberrant PMN influx is also implicated in the pathogenesis of numerous inflammatory diseases of the gut and lungs. Fucosylated terminal glycans from the Lewis glycan family, such as Lewis‐x (Lex) and Sialyl Lewis‐x, have previously been implicated in the regulation of important PMN functions, including Selectin‐mediated PMN transendothelial trafficking. While such glycans based on the type 2 sequence (Galb1‐4GlcNAc‐R) are abundant on PMNs, the presence of type 1 Galb1‐3GlcNAc‐R glycans required for the expression of Lewis‐a (Lea) have not yet been reported. Here, we conclusively report that Lea is expressed in human PMNs as probed using mAbs whose specificity was confirmed using glycan array technology. Lea function was further probed using Lea‐selective mAbs and a Lea binding lectin resulting in increased PMN chemotaxis and migration across model intestinal epithelia. Analyses of glycan synthetic machinery in PMN revealed expression of a b1–3 Galactosyltransferase and an α1–4 Fucosyltransferase, glycosyltransferases that are required for Lea synthesis. Specificity of findings to Lea was confirmed by absence of antibody‐mediated effects using PMN from individuals deficient in α1–4 fucosylation. These results suggest that PMN expression of Lea has important functional consequences that may be relevant during PMN trafficking within inflamed mucosal tissues. We therefore propose that PMN Lea represents a new target for regulating intestinal innate immunity and modulating inflammation in diseases where dysregulated PMN influx is associated with bystander tissue damage. Furthermore, differential responses of human PMN to physiological ligands of Lea (based on an individuals Lewis phenotype) may provide insights into the mechanisms linking specific Lewis phenotypes with differential susceptibilities to bacterial infections, viral infections and coronary heart disease.

Support or Funding Information

NIH ‐ RO1 DK072564‐21 (Parkos)

CCFA ‐ Career Development Award (314660) (Brazil)
Gut Microbial Metabolites Establish a Gradient of Extracellular Protons, Which Mediate Microbiota‐Stimulated Intestinal Repair via Proton‐Sensing G‐Protein Coupled‐Receptors
Authors: Alam M. Ashfaqul , Wu Huixia , Matthews Jason , Saeedi Bejan , Jones Rheinallt , Neish Andrew S.
Published: November 2023

The gut commensal microbiota interacts with intestinal epithelial cells to ensure intestinal homeostasis, development, and repair. Tissue regeneration is a complex but coordinated cellular process that involves both cellular proliferation and migration. We recently reported that the intestinal wound microenvironment specifically enriches a mucosa‐associated microbial consortium, which promoted repair of mucosal injuries. The mammalian gut microbiota generates a diverse array of metabolites that may influence host cellular reparative responses. We performed an unbiased screening analysis by mass spectrometry‐based metabolomic profiling of intact and wounded mucosa in germ‐free and conventional mice. Unlike the germ‐free animals, the colon of the conventional mice demonstrated increased amounts of acidic microbial metabolites, which established an extracellular pH gradient with more acidic pH at the apex of the colonic crypt. These findings led us to hypothesize that the intestinal microbiome‐produced metabolites generate a gradient of extracellular protons, which influence intestinal barrier function and mucosal homeostasis. We found that the colonic epithelial cells of conventional mice express elevated levels of the proton‐sensing G‐protein coupled‐receptors GPCR4 and GPCR68. Intriguingly, the murine colonic contents or a specific metabolite, 2‐hydroxy‐4‐methylpentanoic acid (HMP) decreases the extracellular pH to modulate claudin‐4 dependent paracellular permeability and to regulate the proliferation of colonic epithelial cells in a GPCR68 and GPCR4‐dependent manner. Importantly, our study revealed that GPCR68 and GPCR4 are activated by different levels of proton concentrations, show differential expression pattern along the murine colonic crypt, and also have an opposing functional role in colonic epithelial cell proliferation in mice. Collectively, our data highlight the importance of microbe derived metabolites in modulating the extracellular proton concentration in the gut mucosal microenvironment. Moreover, our findings show that the GPCR4 and GPCR68 function as the sensor of microbially modulated proton gradient that is potentially involved in the maintenance of gut mucosal homeostasis, repair, and barrier function.

Support or Funding Information

Career Development Award of Crohn's and Colitis Foundation of America (CCFA)
Selective intestinal epithelial loss of Junctional Adhesion Molecule‐A results in enhanced intestinal permeability and increased susceptibility to colitis
Authors: Flemming Sven , Luissint Anny‐Claude , Nusrat Asma , Parkos Charles A.
Published: November 2023

Junctional Adhesion Molecule‐A (JAM‐A) is a transmembrane protein that is expressed in epithelial cells and leukocytes. JAM‐A has been proposed to regulate epithelial barrier function and leukocyte transendothelial migration. Since the tissue specific functions of JAM‐A in the intestinal epithelium have not been elucidated yet, we generated epithelial‐targeted JAM‐A deficient mice (Villin‐cre; JAM‐A fl/fl) and tamoxifen‐inducible epithelial‐targeted JAM‐A deficient mice (Villin‐creERT2; JAM‐A fl/fl) to gain insights into the relative contributions of JAM‐A in regulating intestinal barrier function under steady state and inflammatory conditions. Intestinal epithelial‐targeted loss of JAM‐A resulted in compromised intestinal epithelial barrier function with increased paracellular permeability to 4kDa FITC‐dextran under steady state conditions indicating epithelial JAM‐A as major contributor in epithelial barrier homeostasis. Interestingly, neither mice with constitutive loss of epithelial JAM‐A (Villin‐cre; JAM‐A fl/fl) nor mice with acute loss of JAM‐A (Villin‐creERT2; JAM‐A fl/fl) developed spontaneous colitis. Challenge of Villin‐cre; JAM‐A fl/fl mice with pro‐inflammatory cytokines (TNFa and IFNg) led to a further significant increase in epithelial paracellular permeability, supporting the role of epithelial JAM‐A in barrier compromise during mucosal inflammation. To further confirm the crucial role of epithelial JAM‐A in regulating epithelial barrier function under inflammatory conditions, we performed experiments using an acute DSS induced injury model of colitis and observed that Villin‐cre; JAM‐A fl/fl showed increased susceptibility to colitis as has been reported for JAM‐A −/− mice. Given the increase in sensitivity to development of colitis observed in the JAM‐A deficient mice, we established an intestinal loop model of acute inflammation to analyze the contribution of JAM‐A in regulating neutrophil transepithelial migration (TEpM). With this model, we quantified transmigrated PMNs in an isolated segment of the ileum or colon by flow cytometry and immunofluorescence staining. In JAM‐A −/− mice, we observed delayed neutrophil recruitment into the intestinal lumen with accumulation of neutrophils in the mucosal subepithelial space in response to the chemoattractant leukotriene B4 despite significantly increased paracellular permeability. Analogous studies using mice with epithelial and leukocyte targeted loss of JAM‐A are underway. These findings provide novel insight on the pivotal role of epithelial‐specific loss of JAM‐A in regulation of mucosal barrier function under steady state and inflammatory conditions and highlight a novel contribution of JAM‐A in the process of PMN transepithelial migration.

Support or Funding Information

RO1 DK072564‐21

DFG FL870/1‐1
Neuregulin‐1β Induces ErbB3‐dependent Proliferation and Survival of Normal Human Cardiac Ventricular Fibroblasts
Authors: Galindo Cristi Lara , Kirabo Annet , Gupte Manisha , Ryzhov Sergey , Sawyer Douglas B
Published: November 2023

Neuregulin‐1β (NRG‐1β) is critical for cardiac development and repair and is currently being assessed as a possible therapeutic for systolic heart failure. Our laboratory and others have shown that NRG‐1β improves heart function in several animal models of heart disease, and several human trials indicate that it is a promising treatment for human heart disease. We previously demonstrated that NRG‐1β reduces cardiac fibrosis in an animal model of myocardial infarction, suggesting that it might influence cardiac fibroblast signaling. Here we show that NRG‐1β receptors (ErbB2, ErbB3, and ErbB4) are indeed expressed in normal human cardiac ventricular (NHCV) fibroblasts. Treatment of NHCV fibroblasts with exogenous recombinant NRG‐1β induced activation of the AKT pathway, which was phosphoinositide 3‐kinase (PI3K)‐dependent. Moreover, the NRG‐1β‐induced PI3K/AKT signaling in these cells required phosphorylation of both ErbB2 and ErbB3 receptors at tyrosine (TY)1248 and TY1289 respectively. RNASeq analysis of NRG‐1β‐treated cardiac fibroblasts obtained from three different donor hearts revealed a global gene expression signature consistent with cell growth and survival. We confirmed enhanced cellular proliferation and viability in NHCV fibroblasts in response to NRG‐1β, which was abrogated by PI3K, ErbB2, and ErbB3 inhibitors. These novel findings suggest a role for NRG‐1β in the regulation of cardiac ventricular fibroblast growth and survival via ErbB2/ErbB3 receptor phosphorylation with subsequent activation of the PI3K‐AKT signaling pathway.

Support or Funding Information

This work was supported in part by National Institutes of Health grants 1K01HL13049701(Kirabo) and K01HL121045 (Galindo). VANTAGE is supported in part by CTSA Grant (5UL1 RR024975‐03), the Vanderbilt Ingram Cancer Center (P30 CA68485), the Vanderbilt Vision Center (P30 EY08126), and NIH/NCRR (G20 RR030956).
Function of TGF‐β Regulated NcRNAs in Cardiac Hypertrophy
Authors: Yang Xiao
Published: November 2023

Cardiac hypertrophy is an adaptive enlargement of the myocardium in response to physiological or pathological stimuli. The role of TGF‐b signaling in cardiac hypertrophy has been being debated. We have previously shown that the function of endogenous TGF‐b/Smad signaling in maintaining cardiac homeostasis involves the downregulation of miRNAs inducing cardiac hypertrophy. We found that miR‐199a acts as a key regulator of cardiac autophagy and cardiac hypertrophy. We generated cardiac‐specific miR‐199a transgenic mice and demonstrated that overexpression of miR‐199a was sufficient to inhibit cardiomyocyte autophagy and induced cardiac hypertrophy in vivo. Mechanistically, miR‐199a impaired cardiomyocyte autophagy in a cell‐autonomous manner by targeting glycogen synthase kinase 3β (GSK3β)/mammalian target of rapamycin (mTOR) complex signaling. Activation of autophagy using rapamycin was sufficient to restore cardiac autophagy and decrease cardiac hypertrophy in miR‐199a transgenic mice. Interestingly, inhibition of endogenous miR‐199 led to physiological cardiac hypertrophy, uncovering a surprising role for endogenous miR‐199 in the maintenance of cardiac hemostasis. Very recently, we found that a TGF‐b regulated lncRNA induced cardiac hypertrophy in transgenic mice. These results suggest that targeting ncRNAs regulated by TGF‐b is a potential therapeutic strategy for cardiac disease.
Regulation of translational fidelity and neurodegeneration
Authors: Ackerman Susan L.
Published: November 2023

The faithful execution of protein production from mRNAs is largely controlled by accurate charging of tRNAs by the aminoacyl tRNA tRNA synthetases. Many of these enzymes have editing domains that can recognize and correct mischarging of cognate tRNAs. We previously identified a spontaneous mutation in the editing domain of the mouse alanyl tRNA‐synthetase gene which leads to aggregates of misfolded proteins and degeneration of cerebellar Purkinje cells. By forward genetics we have identified a modifier gene of this mutation that prevents aggregate formation and neurodegeneration. Our data demonstrates that this novel vertebrate‐specific protein plays an important, previously unappreciated role in translational fidelity.

Support or Funding Information

This work was supported by NIH and Howard Hughes Medical Institute.
A versatile chaperone network promoting the aggregation and disaggregation of misfolded proteins
Authors: Bukau Bernd , Nillegoda Nadinath , Wentink Anne , Ungelenk Sophia , Ho Chi‐ting , Mogk Axel
Published: November 2023

Misfolded proteins are sticky and tend to form intracellular aggregates underpinning age‐related deterioration and disease. Normally, multi‐tiered cellular quality control systems monitor and repair protein damage, limiting aggregation. Severe stress however overloads these systems allowing aggregates to accumulate. This activates a cellular machinery which mediates the organized aggregation of misfolded proteins as well as the subsequent solubilisation and refolding and of aggregated proteins. This machinery plays a pivotal role in cell survival under protein folding stress and in counteracting disease and age‐associated cell toxicities.

Small heat shock proteins (sHsp) constitute an evolutionary conserved yet diverse family of chaperones acting as first line of defense against proteotoxic stress. The yeast sHsps Hsp42 and Hsp26 promote the storage of misfolded proteins in native‐like conformation which facilitates disaggregation by ATP dependent chaperone systems. In plants, fungi and bacteria the central disaggregation machinery is a powerful bi‐chaperone system comprised by the AAA+ disaggregase Hsp100 (Hsp104, ClpB) and the cooperating Hsp70 chaperone with its co‐chaperones, J‐domain proteins (JDPs) and nucleotide exchange factors (NEFs). Metazoan cells lack Hsp100 disaggregases, but have evolved a potent Hsp70‐based disaggregation machinery which relies on synergistic action of Hsp70 and its co‐chaperones. This activity has broad specificity and can even disassemble amyloid fibrils of α‐synuclein. A different disaggregation strategy has therefore evolved in evolution of metazoa.

Support or Funding Information

German Research Foundation (DFG)
Modeling cellular network dynamics of liver homeostatic renewal
Authors: Vadigepalli Rajanikanth , Cook Daniel , Ogunnaike Babatunde
Published: November 2023

Recent experimental studies identified specific subpopulations of self‐renewing hepatocytes with ability to populate the liver during homeostatic maintenance of the tissue. It remains an open question as to how this process of precursor transformation into mature hepatocytes is regulated by molecular pathways and tissue microenviroment to yield robust homeostatic renewal. We explored the contribution of putative control mechanisms that yield robustness to the renewal process by developing and analyzing a computational model of liver homeostatic renewal that considers a cellular network of precursor cells and mature hepatocytes. We demonstrate that the renewal network without feedback and nonlinear dynamics cannot maintain liver tissue in response to repeated injury. We modified the model to consider multiple alternatives including capacity constraints on proliferation, inhibition of precursor proliferation and transformation by mature hepatocytes, and putative precursor replenishment from non‐hepatocyte sources. We followed a Design of Experiments approach to investigate the system dynamics under all possible combinations of feedback configurations, specifically characterizing recovery of precursor and mature hepatocyte populations in response to a wide variety of disturbances. This unbiased exploration led us to identify a model configuration that is most robust in maintaining liver homeostasis. We compared the dynamics of the most robust model configuration with the available experimental data on the effects of hepatocyte senescence and stem cell transplantation on liver tissue renewal. We investigated the dynamics of the homeostatic renewal network in response to chronic repeated injury. Our results suggest that increasing frequency and magnitude of chronic repeated injury destabilizes the liver homeostasis within several months, which is inconsistent with epidemiological observations of a much slower decay of liver function over several years. We interpret these findings as suggestive of the presence of additional stabilizing controls potentially by the non‐parenchymal cells. We modified the model to include manipulation of the liver microenvironment signals by the liver non‐parenchymal cells as an additional layer of feedback control over hepatocyte levels. Our simulations and model analyses lead us to predict that robust homeostatic balance of hepatocytes is achieved by a combination of intrinsic system stability and control by non‐parenchymal cells. Taken together, our computational modeling study suggests that homeostatic renewal and maintenance of liver tissue is achieved through a coordinated regulation of the process by a combination of cell‐intrinsic and intercellular feedback control mechanisms.

Support or Funding Information

Research Support: R01 AA018873, T32 AA007463, F31 AA023445
Role of Hepatic O‐GlcNAcylation on Acetaminophen‐Induced Liver Injury
Authors: McGreal Steven , Bhushan Bharat , Walesky Chad , McGill Mitchell R , Weemhoff James L , Jaeschke Hartmut Jaeschke , Zhang Zhen , Tan Ee , Slawson Chad , Zachara Natasha E
Published: November 2023

Overdose of acetaminophen (APAP), the most widely used analgesic, results in acute liver failure. We have investigated the role of a post‐translational modification of proteins called O‐GlcNAcylation in pathogenesis of APAP‐induced liver injury, where a single β‐D‐N‐acetylglucosamine (O‐GlcNAc) moiety is added to proteins by an enzyme called O‐GlcNAc transferase (OGT) and removed by an enzyme called O‐GlcNAcase (OGA). Male C57BL/6J mice were treated with 300 mg/kg APAP followed by Thiamet‐G (TMG, 400 mg/kg) a specific inhibitor of OGA that induces O‐GlcNAcylation, 1.5 hr after APAP administration. Progression of liver injury was studied over a time course of 0 to 24 hr. TMG treatment resulted in significant increase in hepatic O‐GlcNAc. The mice treated with 400 mg/kg TMG exhibited significantly higher APAP‐induced liver injury as indicated by increase in serum transaminase levels and histopathological analysis, as well as a prolonged JNK activation. Treatment with TMG did not affect hepatic CYP2E1 levels, APAP protein adduct formation, APAP induced mitochondrial damage, hepatic glutathione (GSH), or depletion of GSH after APAP treatment. C57BL/6J mice were also treated with 50 mg/kg TMG every other day for 15 days followed by 300 mg/kg APAP and sacrificed at 24 hr. Mice treated with 50 mg/kg TMG showed a similar increase in APAP‐induced liver injury. Next we used hepatocyte specific OGT knockout mice (OGT KO), which have decreased O‐GlcNAcylation to study APAP toxicity. OGT KO and WT control mice were treated with 300 mg/kg and sacrificed on a timecourse from 0–24 hr. OGT KO mice showed dramatic decrease in liver injury as compared to WT mice. APAP protein adducts was significantly decreased in OGT KO mice when compared to WT control mice. There was no difference CYP2E1 activity showing that OGT KO did not alter cytochrome P450 levels and alter APAP metabolism. Hepatic GSH depletion was equal in OGT KO and WT mice but GSH was rapidly replenished by 6hr after APAP treatment in OGT KO mice, while WT mice did not fully replenish until 24hr post APAP. Taken together, these data indicate that induction in cellular O‐GlcNAcylation exacerbates and decrease in O‐GlcNAcylation protects from APAP induced liver injury. These studies have identified a novel mechanism of pathogenesis of acute liver injury induced by APAP and highlighted a novel therapeutic target for acute liver failure.

Support or Funding Information

R01DK098414
The Regulatory Role of CD99L2 in Inflammation
Authors: Rutledge Nakisha S , Watson Richard L , Sullivan David P , Muller William A
Published: November 2023

The inflammatory response involves a series of steps in which inflammatory stimuli activate endothelium of local blood vessels to express adhesion molecules that recruit circulating leukocytes from the blood. Transendothelial Migration (TEM) is a crucial step in the inflammatory response as it is the process in which leukocytes leave the bloodstream to enter the inflamed tissues. PECAM and CD99 are two molecules important for the initiation and completion of TEM, respectively.

CD99‐like 2 (L2) is a highly glycosylated 52 kD type‐1 membrane protein that is the only molecule in the genome related to CD99. Similar to CD99, L2 is expressed at the borders of endothelial cells and on the surface of leukocytes. Blocking L2 using antibodies significantly reduces the recruitment of neutrophils and monocytes to sites of inflammation in mice. Similarly, L2 knockout mice have an inherent defect in transmigration into inflammatory sites. Thus, L2 has been shown to be another important protein for TEM; however, how it regulates this process is not known. L2 is different enough from CD99 (60% larger and with only 38% sequence identity) that it is not clear whether it regulates TEM by the same mechanism as CD99. Furthermore, all of the published studies on L2 have been performed in mice. The role of L2 in TEM of human cells has yet to be shown. In order to study the mechanism used by L2 and the relevance to human inflammation, we studied the role of L2 on human cells in vitro. Using an endpoint TEM assay, we show that inhibiting L2 function using either a blocking antibody or shRNA reduces TEM of human monocytes to 30% of control levels. Like PECAM and CD99, homophilic interactions between L2 on leukocytes and L2 on the endothelium are required for this process.

Previous studies have shown that PECAM regulates a step in TEM that is “upstream” of the one regulated by CD99. In order to determine where L2 functions in relation to PECAM and CD99, we used an extended version of our TEM assay, the sequential block assay. Our data show that L2 functions downstream of PECAM and upstream of CD99. Preliminary data suggest that L2 can promote TEM by engaging either the signaling pathway used by PECAM or the one used by CD99. These data are consistent with L2 functioning between the PECAM and CD99. The data we have obtained in both humans and mice identify L2 as a potential target for anti‐inflammatory therapy.

Support or Funding Information

T32‐5T32AI007476‐19

R37‐HL064774

F31‐HL131355‐01