bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tissue Factor Enhances the Alveolar Epithelial Barrier Integrity during Acute Lung Injury
Authors: Sucharski Holly , Putz Nathan , Shaver Ciara , Ware Lorraine , Bastarache Julie 
Published: June 2021

IntroductionWe have previously reported that lung epithelial tissue factor (TF) knockout (TFΔEpi) mice have increased alveolar capillary barrier permeability. Ultrastructurally, these mouse lungs have profound morphological defects in epithelial attachment to the basement membrane. Adhesion/migration are regulated in part by integrins which bind the extracellular matrix proteins to modulate cytoskeletal dynamics. In cancer cells, TF binds β1 integrin and increases cell migration, a finding that suggests a role for non‐coagulative mechanisms of TF in cell adhesion and migration. We hypothesize that TF‐β1 integrin binding promotes alveolar epithelial barrier integrity through cell adhesion and migration during acute lung injury (ALI).MethodTF overexpressing (TF+Epi) and knockout (TFΔEpi) mice, along with TF knockout A549 cells (A549ΔTF) were used to test whether lung epithelial TF is critical for the integrity of the alveolar epithelial barrier. TF+Epi mice were treated with intratracheal PBS or LPS and lung permeability was measured by bronchoalveolar lavage (BAL) fluid protein level. Alveolar type II epithelial cells (ATII) were isolated from TFΔEpi and TF+Epi mice to measure β1 integrin protein levels. A549ΔTF cells were treated with LPS (100ug/mL) or PBS for 24 hours before western blot of β1 integrin expression. Migration was assessed in wild‐type and A549ΔTF cells using Electric Cell‐substrate Impedance Sensing (ECIS) on cell monolayers. Adhesion was assayed by plating wild‐type and A549ΔTF cells on matrigel and quantifying the absorbance of crystal violet stained adherent cells.ResultsTF+Epi mice had decreased lung permeability (BAL protein 303 μg/mL +/− 62 versus 416 +/− 137 in control, p=0.025) following LPS challenge. A549ΔTF cells had significantly decreased cell adhesion (Figure) (absorbance 0.308 +/− 0.119 versus 0.603 +/− 0.246 in wild type, *p<0.001) along with decreased migration (p=0.017) compared to control A549 cells with wild type TF expression levels. A549ΔTF cells had decreased β1 integrin protein levels (relative expression 0.017 +/− 0.01 versus 0.61 +/− 0.02 control, p=0.036) following LPS challenge. ATII cells isolated from TFΔEpi mice also have decreased β1 integrin protein levels.ConclusionsTF contributes to alveolar barrier integrity in part through a mechanism dependent on β1 integrin. These data provide support that lung epithelial TF may play a non‐coagulative role in protection during ALI. This novel role for TF in maintaining alveolar epithelial barrier integrity offers a potential therapeutic target during ALI.Support or Funding InformationVanderbilt University Initiative for Maximizing Student Diversity funding through the NIH, Nashville Veterans Affairs Medical Center, Funding: HL090785, HL103836This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Tumor Necrosis Factor alpha (TNFα) reduces intestinal ascorbic acid (AA) uptake
Authors: Subramanian Veedamali S. , Sabui Subrata , Subramenium Ganapathy A. , Marchant Jonathan S. , Said Hamid M. 
Published: June 2021

Intestinal inflammation and systemic bacterial infection are associated with an increase in the level of proinflammatory cytokines like tumor necrosis factor alpha (TNFα) in the intestinal mucosa and blood. Though important for intestinal immunity, TNFα also exerts profound effects on intestinal absorptive and secretory functions through specific intracellular signaling pathways like NF‐κB. Studies have shown that high levels of TNFα are linked to the pathogenesis of diarrhea in inflammatory bowel disease (IBD) and that these patients have low levels of vitamin C. To date, however, there has been little known about the effect of TNFα on intestinal absorption of vitamin C. Ouraim in this study was to address this issue using in vitro (Caco‐2), in vivo(mice), and ex vivo (enteroids) models, together with an array of physiological and molecular biological techniques. TreatingCaco‐2 cells and mice with TNFα led to a significant inhibition of 14C‐AAuptake compared to untreated controls. This inhibition was associated with significant decreases in SVCT‐1 protein, mRNA and hnRNA levels in TNFα treated Caco‐2 cells, mouse jejunum, and enteroids compared to their appropriate controls. TNFα also caused a significant inhibition in the activity of the SLC23A1 promoter in Caco‐2 cells. Further, treating Caco‐2 cells with the NF‐κB inhibitor celastrol blocked the inhibitory effect caused by TNFα on AA uptake, SVCT‐1 protein and mRNA expression, as well as SLC23A1 promoter activity. Finally, treatment of Caco‐2 cells with TNFα lead to a significant inhibition in the expression of the hepatocyte nuclear factor‐1α (HNF1α), which is known to drive the transcription of SLC23A1 promoter. Together, these findings demonstrate that TNFα inhibits intestinal AA uptake and that this effect is exerted, at least in part, at the level of transcription of the SLC23A1 gene through NF‐κB signaling pathway.Support or Funding InformationSupported by NIH grants DK 107474, DK 58057, DK 56057 and a grant from the DVA.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
GluN2A Haploinsufficiency: a Novel Pre‐Clinical Model of Epilepsy
Authors: Wyllie David J. , Booker Sam A. , Yasmin Farhana , Marshall Grant , Marwick Katie F. , Wood Emma R. , Kind Peter C. , Hardingham Giles E. 
Published: June 2021

N‐methyl‐D‐aspartate receptors (NMDARs) are ionotropic glutamate receptors that play pivotal physiological roles during development and maturation of the mammalian central nervous system. Their functional diversity is controlled by nature of the two GluN2 subunits that co‐assemble with two GluN1 subunits in the receptor‐complex. Four GluN2 subunits exist (GluN2A–D) and their expression patterns are developmentally and spatially restricted. In the mammalian forebrain the predominant NMDAR composition is one of a diheteromeric assembly of two GluN1 with (i) two GluN2A subunits (GluN1/2A) or (ii) two GluN2B subunits (GluN1/2B) or a triheteromeric assembly of two GluN1 and one of each of a GluN2A and GluN2B subunit. The GluN2 identity strongly influences NMDAR kinetic behaviour – GluN1/2A and GluN1/2A/2B NMDARs have faster deactivation rates than those exhibited by GluN1/2B. Thus loss or reduced expression of GluN2A will change the kinetic profile of NMDAR populations. It is now recognized that humans who have certain mutations in GluN2A NMDAR subunits or are haploinsufficient for GluN2A protein experience epileptic seizures. To investigate the mechanistic basis of neuronal dysfunction associated with GluN2A reduction we have created a novel transgenic rat line using CRISPR/Cas9 technology, where exon 8 of GluN2 is deleted. We have studied the intrinsic and synaptic properties of hippocampal CA1 pyramidal neurons obtained from rats either completely lacking expression of Glun2A (Grin2A−/−) or ones which are heterozygous for the deletion (Grin2A+/−). Whole‐cell patch‐clamp recordings revealed that compared to recordings from wild‐type (WT) neurons no significant differences are observed in intrinsic excitability of either Grin2A+/− or Grin2A−/− pyramidal neurones when recordings were made from postnatal day 12–14 or postnatal day 28–32 animals. In addition, miniature and spontaneous excitatory and inhibitory synaptic currents recorded from either WT, Grin2A+/− or Grin2A−/− neurons showed little differences in the amplitudes or frequency of events. As is to be expected, however, loss of GluN2A expression leads to a slowing of the duration of the NMDAR‐mediated component of evoked synaptic currents. Our data also indicate that the magnitude of synaptic plasticity at Schaffer collateral/commissural synapses on to CA1 pyramidal neurons is reduced.Support or Funding InformationBiotechnology and Biological Sciences Research Council BB/N015878/1 Epilepsy Research UK P1602This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Effects of Urocortins on Intestinal Ion Secretion in the Mouse Colon
Authors: Liu Sumei , Karo Aaron 
Published: June 2021

Background and AimsUrocortins (Ucn1, Ucn2, and Ucn3) belong to the corticotropin‐releasing factor (CRF)‐like peptide family and bind to two subtypes of CRF receptors (CRF1 and CRF2) to exert their biological effects. Ucn1 binds to both CRF1 and CRF2 receptors with equal high affinity, whereas Ucn2 and Ucn3 bind exclusively to CRF2. CRF and urocortins are expressed in the gastrointestinal tract. CRF has been implicated in stress‐stimulated intestinal ion secretion and diarrhea. However, the effects of urocortins on intestinal ion secretion have remain uninvestigated. The aim of the present study was to investigate the role of urocortins in the regulation of intestinal ion secretion.MethodsMucosa/submucosa preparations from mouse colon were mounted in Ussing flux chambers for measurement of short‐circuit current (Isc) as an indicator of mucosal ion secretion.ResultsApplication of CRF, Ucn1, Ucn2, and Ucn3 to the basolateral side of the preparation increased baseline Isc in a concentration‐dependent manner with an EC50 (in M) of 1.28×10−6, 6.04×10−7, 2.89×10−7, or 2.98×10−7, respectively, with the rank order of potency: Ucn2≈Ucn3>Ucn1>CRF. At 1 μM, Ucn3 caused a greater rise in Isc (ΔIsc: 47.01±8.94 μA/cm2), compared with Ucn2 (17.71±2.63 μA/cm2), Ucn1 (7.06±4.33 μA/cm2), or CRF (8.92±4.11 μA/cm2). The CRF1 receptor antagonist NBI 27914 significantly suppressed Ucn1‐evoked ΔIsc, but had no effect on Ucn2‐ or Ucn3‐evoked ΔIsc. The CRF2 receptor antagonist antisauvagine‐30 significantly suppressed Ucn1‐evoked ΔIsc, and completely blocked Ucn2‐ or Ucn3‐evoked ΔIsc. The neuronal blocker tetrodotoxin had no effect on Ucn1‐, Ucn2‐, or Ucn3‐evoked DIsc.ConclusionsThe results suggest that urocortins stimulate colonic ion secretion independent the submucosal plexus of the enteric nervous system. Both CRF1 and CRF2 receptors are involved in Ucn1‐stimulated ion secretion, while Ucn2‐ and Unc3‐stimulated ion secretion is mediated by the CRF2 receptors. Ucn2 and Ucn3 are more potent than CRF in stimulation of colonic ion secretion and may play a dominant role in stress‐induced hyper secretion and diarrhea.Support or Funding InformationNIH R15 DK097460‐01A1 (SL) and UWL graduate research service and educational leadership grant (AK).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Knockout of Txnip in the Intestinal Epithelial Cells Abrogates the High Fat Diet‐Induced Fructose Uptake in Mice
Authors: Shah Anu , Dagdeviren Sezin , Hundal Henna , Lee Richard T. 
Published: June 2021

Thioredoxin interacting protein (Txnip) was initially identified as a protein that can bind to and inhibit thioredoxin, but it is now recognized to participate in nutrient sensing and carbohydrate metabolism. We recently discovered that Txnip binds to the fructose transporters, Glut 2 and Glut 5, to increase the fructose uptake by enterocytes. Additionally, we demonstrated that mice with diabetes induced by streptozotocin exhibit significantly higher fructose absorption compared to their non‐diabetic counterparts. Interestingly, this increase of fructose absorption in the diabetic state requires Txnip. In the current study, we studied the effects of a high fat diet (HFD) on fructose uptake and the involvement of Txnip in this process while the mice were still euglycemic. We hypothesized that high fat diet (HFD) feeding would increase fructose absorption by the jejunum compared to the controls on standard chow diet (RD), and this increase would be prevented in mice with deletion of Txnip in the intestinal epithelium despite being on a HFD. To test this hypothesis, 8‐week‐old male C57BL/6J wild‐type mice were kept on HFD for 16 weeks. At the end of 16 weeks, HFD‐fed mice not only developed insulin resistance as expected, but also displayed significantly higher fructose absorption (hepatic portal vein blood: p<0.01 and liver: p<0.05 vs regular diet mice, n=6–7 mice/group) 20 minutes after the oral gavage of [14C‐(U)]‐D‐fructose. Interestingly, gene and protein expressions of Txnip were also significantly higher in the jejunal samples from these mice, suggesting a potential role of Txnip in fructose uptake by the HFD‐fed mice. Since fructose absorption primarily occurs in the jejunum, using a cre‐lox breeding strategy, we generated a Txnip villin‐cre mice that lacks Txnip in the intestinal epithelial cells; and then subjected these mice and their cre counterparts to RD/HFD at 7–9 weeks of age. The preliminary data at 1 month post‐diet shows a downward trend of fructose absorption in both RD‐fed and HFD‐fed Txnip villin cre mice compared to cre‐controls that exhibited a physiological level of Txnip in villi. Therefore, our data indicate that HFD facilitates fructose uptake by the intestine, and targeted deletion of Txnip at the intestinal level can decrease absorption of dietary fructose. This finding suggests a molecular mechanism by which a high fat diet can promote additional hepatic lipid synthesis through increased fructose absorption.Support or Funding InformationNational Institute of Health (RTL R01DK107396) and Canadian Diabetes Association (PF‐3‐16‐5176‐AS to AS)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
c‐Src mediates intestinal stem cell response to high fat diet
Authors: Theiss Arianne L. , Han Jie , Jackson Dakota L. , Park Junhyoung , Jung Kwang Hwa , Kaipparettu Benny A. 
Published: June 2021

c‐Src is a commonly upregulated oncogene in colorectal cancer. High fat diet (HFD) augments the numbers and function of Lgr5+ intestinal stem cells (ISCs), increasing the capacity of these stems cells to initiate tumors. Discoveries in triple negative breast cancer models and patient specimens suggest that mitochondrial reprogramming to fatty acid oxidation (FAO) activates c‐Src. Here, we determined the role of FAO induced by HFD on c‐Src activation and ISC self‐renewal. Lgr5‐EGFP‐IRES‐creERT2 (Lrg5‐EGFP) knock‐in mice were fed a dietary chow consisting of 45% kcal fat or a low fat matching diet ad libitum from 8 to 20 weeks of age. Beginning at age 10 weeks, mice were i.p. injected with 20 mg/kg Etomoxir (ETX), an inhibitor of FAO, twice per week. Intestinal enteroids derived from Lgr5‐EGFP mice were treated with constituents of HFD (30 μM palmitic acid and 30 μM oleic acid) every 3 days for 2 weeks ± 20 μM PP2, a Src inhibitor. Numbers of intestinal Lgr5‐GFP+ cells were quantitated and isolated by flow cytometry and expression of c‐Src target gene Cyclin D1 and ISC self‐renewal gene Olfm4 were measured by qPCR. c‐Src activation was measured in human colon cancer cell lines HCT‐116 and Caco2 treated with 200 μM ETX or 10 mM L‐carnitine (FAO activator) for 16 hr. HFD increased the number of Lgr5+ ISCs and expression of Cyclin D1 and Olfm4, which were prevented by ETX. PP2 inhibition of c‐Src in enteroids prevented the palmitic acid/oleic acid‐induced increase in Lgr5+ ISC numbers. ETX decreased and L‐carnitine induced c‐Src activity in HCT‐116 and Caco2 cells. Our data provide novel evidence that the Src pathway plays an important role in ISC response to constituents of HFD.Support or Funding InformationCollaborative Faculty Research Investment Program (CFRIP), Baylor Scott & White Health and Baylor College of MedicineThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Dietary Fat Quality Plays a Sex‐Specific Role in Attenuating Metabolic Risk Factors in Aging CD‐1 Mice
Authors: Unger Allison , Jetton Thomas , Kraft Jana 
Published: June 2021

Diet quality (e.g., dietary fat type) and aging play an important role in the development of type 2 diabetes, however, is not known if long‐term consumption of diets with differing fatty acid profiles can modulate metabolic risk factors in an aging population. Accordingly, we aimed to examine how different sources of fatty acids added to a western‐style diet might improve metabolic risk factors during aging. Sixty male and female outbred CD‐1 mice (n = 10/group) were fed isoenergetic high‐fat diets (40% kcal fat) containing either (1) American diet fat blend (100%) (Control, CON; reflecting the average fatty acid profile consumed in the United States linked to dysmetabolism and increased inflammation), (2) CON fat (70%) + 30% butter oil (BO), (3) CON fat (70%) + 30% echium oil (EO), or (4) CON fat (70%) + 30% fish oil (FO) for a total of 14 months. Standard physiological measurements and glucose homeostatic assays (i.e., intraperitoneal insulin and glucose tolerance tests) were performed at regular intervals (3, 6, 9, and 12 months of dietary intervention) and key tissues were harvested at 14 months of age. Despite CON males having a consistently lower feed intake (P < 0.001) and weight gain (P = 0.002), they exhibited a markedly reduced glucose tolerance by 9 months (P = 0.02) compared to FO (P = 0.005) and EO males (P < 0.001) which persisted through 12 months. CON males also had an increased accumulation of triacylglycerols in the liver compared to EO, BO, and FO males at 14 months (P < 0.001). Although BO males showed transiently reduced glucose tolerance at 9 months (P = 0.02) compared to FO (P = 0.009) and EO males (P = 0.001), this phenotype dissipated by 12 months. EO males exhibited a trend of overall improved insulin sensitivity compared to BO males (P = 0.05). While females displayed no differences in feed intake, weight gain, glucose tolerance, or insulin sensitivity among the diet groups at 3, 6, and 9 months, unexpectedly, by 12 months, all groups displayed improved glucose tolerance and insulin sensitivity compared to earlier time points (P < 0.001 and P = 0.02, respectively). Our study provides evidence that dietary fat quality impacts metabolic risk factors in a sex‐specific manner.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Artificially Sweetened Vitamin Drink Consumption Reduces Insulin Sensitivity and Alters One‐Carbon, B‐Vitamin Dependent Metabolism in Adolescents
Authors: Mayengbam Shyamchand , Virtanen Heidi , Hittel Dustin S. , Elliott Charlene , Reimer Raylene A. , Vogel Hans J. , Shearer Jane 
Published: June 2021

ImportanceDiscretionary fortified beverages contain several ingredients such as vitamins and minerals in excess amounts, yet their consumption and sales have been burgeoning. Marketed as providing a unique health benefits to consumers, concerns have been raised about the overconsumption of some nutrients, especially in children and adolescents.ObjectiveTo evaluate the impact of discretionary fortified beverage consumption on energy metabolism, gut hormones and metabolic profiles of adolescents.DesignA double blind, randomized, placebo‐controlled crossover trial examined the metabolic effects of a concentrated, small format B‐vitamin fortified beverage. Healthy adolescents (10 males, 10 females, 13–19y) completed two trials separated by at least 1 week, consuming either water as placebo (PL) or an artificially sweetened discretionary fortified beverage (FB, 1.5ml/kg), which were given 40min prior to an oral glucose tolerance test (OGTT).MethodBlood samples were collected at baseline and at different time‐points throughout the OGTT for insulin, gut hormones and 1H‐NMR spectroscopy‐based metabolomics analyses. To evaluate gene‐metabolic interactions, a group of the most common single nucleotide polymorphisms (SNPs) linked to B‐vitamin metabolism was also assessed.ResultsPlasma glucose was not different between the treatment groups (p=0.111). However, plasma insulin was significantly higher in the FB group (p=0.003) and accompanied by a 28% decrease in insulin sensitivity in FB compared to PL as indicated by the composite Insulin Sensitivity Index (ISI). Gut hormone secretion was also differentially modulated by the consumption of FB. We found a significant increase in AUC of GLP‐1 (p<0.001), glucagon (p=0.015), PYY (p=0.001) and C‐peptide (p=0.017) in FB compared to the PL group. Employing 1H‐NMR metabolomics, we also show perturbations to one carbon, B‐vitamin linked sulfur amino acid metabolism with FB consumption. This metabolic response was dependent on genotypic variance at rs651852 (Betaine Homocysteine methyltransferase, BHMT, p<0.05).ConclusionCurrent data provide evidence that FB are not inert, but may promote insulin resistance, perturb one carbon, B‐vitamin‐linked metabolism and differentially modulate gut hormone secretion in adolescent consumers. Results may warrant reconsideration of regular, artificially sweetened FB consumption for adolescents at risk for obesity and metabolic disease.Support or Funding InformationThe research was funded by the Alberta Children's Hospital Research Institute and the National Science and Engineering Council of Canada (JS). SM is funded through an Eyes High Postdoctoral Fellowship and an Alberta Innovates Health Solutions Postdoctoral Fellowship.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.