bluuebunny/crossref_metadata_2025_split huggingface dataset:
In the Short Term, Poor Nutrition Promotes Simple Steatosis without Inflammation in Adolescent Rats
Authors: Crawford Meli'sa , Liss Tyler , Calhoun Matthew , Sweazea Karen 
Published: November 2023

The development of hepatic steatosis in adults has been linked to high caloric intake. However, less is known about the physiological consequences of this disease during adolescence. The present study examined the association of high caloric intake and hepatic steatosis in adolescent rats. Six‐week old male Sprague‐Dawley rats were fed one of the following diets: standard rodent chow (18.9% protein, 57.33% carbohydrates), high‐sucrose (HS: 20% protein, 70% carbohydrates (34.5% sucrose), 10% fat) or high‐fat (HF: 20% protein, 20% carbohydrates (6.8% sucrose), 60% fat) for 6 weeks. Following the diet, animals were euthanized (sodium pentobarbital; 200 mg/kg, i.p.) and livers extracted for analyses. An increase in Oil Red O stained areas of liver sections provided evidence for the development of steatosis in the HF fed animals that was confirmed by increased triglyceride concentrations in the liver as compared to animals fed the chow or HS diets (20.73 ± 2.09, 9.75 ± 0.52, and 10.76 ± 0.74 mg triglycerides/g tissue, respectively; p < 0.001). Despite the observed steatosis, western blot analyses showed no significant differences between groups in proteins associated with insulin signaling (p‐PI3K; p85, p=0.711; p55, p=0.740), gluconeogenesis (PEPCK‐C, p=0.333), immune response (XBP1; p=0.613) or inflammation (TLR‐4, p= 0.932; iNOS, p=0.675). The short feeding protocol used in the current study may explain the lack of measurable alterations in protein expression as others typically examine the effects of high caloric diets for 8–12 weeks before measuring changes. Together these findings suggest that short term high fat intake promotes simple steatosis in the absence of changes in insulin signaling or inflammation.Support or Funding InformationThis study was funded in part by new faculty start up funds, and Barrett, The Honors College, Arizona State University.
Prevention and Mitigation of Radiation‐Induced Colonic Epithelial Barrier Dysfunction by Lysophosphatidic Acid Receptor‐2 Agonists
Authors: Shukla Pradeep K , Gangwar Ruchika , Manda Bhargavi , Meena Avtar S , Balogh Andrea , Szabo Erzsebet , Lee Sue Chin , Tigyi Gabor , Rao Radhakrishna (RK) 
Published: November 2023

BackgroundLysophophatidic acid (LPA), a lipid growth factor, regulates secretion, absorption, cell survival and migration in the intestinal epithelium. Altered LPA activity is associated with many gastrointestinal (GI) diseases such as inflammatory bowel disease, colon cancer and GI acute radiation syndrome (GI‐ARS). Disruption of intestinal epithelial tight junctions (TJ) and gut barrier dysfunction is associated with the pathogenesis of many GI diseases. In this study, we evaluated the effect of LPA2 receptor on radiation‐induced disruption of intestinal epithelial barrier by in vivo and in vitro studies.MethodsWT and LPA2−/− mice were subjected to total body irradiation (TBI; 4Gy) or partial body irradiation (PBI‐BM5; 16 Gy). RP‐1, a stable, LPA2‐specific, LPA analog was administered (0.1 mg/kg, s.c.) 30 min prior to TBI or 24 h after PBI‐BM5. For in vitro studies, Caco‐2 and mICC12 cell monolayers were treated with LPA (10 mM) 30 min prior to irradiation (4 Gy). The barrier function was evaluated by measuring transepithelial electrical resistance (TER) and FITC‐inulin flux. TJ integrity was analyzed by immunofluorescence confocal microscopy for occludin, ZO‐1, F‐actin and claudins. Protein thiol oxidation was evaluated by measuring reduced and oxidized protein thiols by fluorescence staining using BODIPY FL‐N‐(2‐aminoethyl)maleimide as a probe. Colonic sections were also stained for Nrf2, the transcription factor responsible for regulation of antioxidant gene expression.ResultsTBI induced redistribution of TJ and AJ proteins from the epithelial junctions disruption in ileum and colon within 2 hours post irradiation (post‐IR), and the damage was sustained at least until 24 hours. TBI‐induced disruption of TJ and AJ was more severe in LPA2 −/− mice. On the other hand, RP‐1 administration in WT mice completely significantly attenuated TBI‐induced TJ and AJ disruption. PBI induced TJ disruption at 48 hours post‐IR, which was sustained at least until 100 hours. RP‐1 administered 24 h after IR mitigated PBI‐induced loss of TJ integrity. Both TBI and PBI depleted reduced protein thiols in colonic epithelium, which was blocked by RP‐1 administration. This effect of RP‐1 was associated with mitigation of PBI‐induced reduction of Nrf2 levels in colonic epithelium. In Caco‐2 and mICC12 cell monolayers, IR reduced TER, elevated inulin permeability and induced redistribution of TJ proteins in Caco‐2 and mICC12 cell monolayers. LPA (10 mM) administration, blocked IR‐induced decrease in TER, increase in inulin permeability and redistribution of TJ proteins.ConclusionThese results indicate that LPA2 receptor agonists prevent and mitigate radiation‐induced colonic epithelial barrier dysfunction. Studies in Caco‐2 and mICC12 cells indicate that LPA agonists may directly impact the intestinal epithelial cells. Supported by NIH grant DK55532
Delta‐Tocotrienol Regulates Lipid Metabolism in Livers of High Fat Fed Mice
Authors: Ramalingam Latha , Allen London , Scoggin Shane , Gurvinder Kaur , Tomison Michael D , Shen Chwan‐Li , Chung Eunhee , Dufour Jannette , Moustaid‐Moussa Naima 
Published: November 2023

Non‐alcoholic fatty liver disease (NAFLD) affects more than 70% of patients with obesity. Several plant bioactive compounds with anti‐inflammatory properties are known to reduce steatohepatitis and associated metabolic complications. Hence we are investigating the regulation of hepatic metabolism by delta‐tocotrienol (δT3), member of the vitamin E family. We hypothesize that delta‐tocotrienol will reduce fatty liver and steatohepatitis through its anti‐inflammatory and lipid lowering properties. To test our hypothesis, C57BL/6J male mice were fed high fat (HF) diet with or without supplementation of increasing levels of δT3 (up to 1600mg/kg) for 14 weeks and compared to mice fed either low fat or metformin. Glucose tolerance tests revealed that mice supplemented with tocotrienol rapidly cleared glucose suggesting that liver plays a role in maintaining glucose homeostasis. By measuring expression of hepatic lipid metabolizing genes, we found that these changes were in part due to increased fatty acid oxidation and reduced fatty acid synthesis in the liver. Furthermore, hematoxylin and eosin staining of liver tissue sections demonstrated significant reductions in liver triglyceride content. Additional studies are ongoing to further understand mechanisms underlying regulation of lipid metabolism by delta‐tocotrienol. In conclusion, our results indicate that delta‐tocotrienol exerts beneficial effects in high fat diet‐induced steatohepatitis, which warrants further investigation.Support or Funding InformationSupported by a research grant from American River Nutrition
Hypoglycaemia Modulates The Patterns Of Ventilatory Responses Evoked By Chemoreceptor Stimulation
Authors: Coney Andrew Mark , Mobley Alastair , Ray Clare 
Published: November 2023

Hypoglycaemia (HG) evokes a counter‐regulatory response to restore arterial blood glucose levels. Additionally, HG has also been shown to evoke an increase in ventilation whilst maintaining normocapnia suggesting the ventilation remained matched to metabolism. Whilst it has been shown that HG induces an increase in CO2 sensitivity, there is a lack of data on how HG may modulate the pattern of breathing in normoxia as well as during chemoreceptor‐mediated responses. Whole body plethysmography (WBP) allows the measurement of respiratory variables in conscious unanesthetised animals under baseline conditions as well as during hypercpanic or hypoxic challenges.WBP was used to measure the ventilatory responses to air breathing (21% O2), acute hypoxia (10% O2) and hypercapnia (8% CO2) in male Wistar rats that had free access to food, were fasted overnight or were made hypoglycaemic by insulin injection. Blood glucose levels tended to be lower after fasting but not significantly (8±0.8mM vs 6.8±0.5mM), however, insulin injection did induce a significant HG (3.8±0.5mM). HG induced an increase in response to hypercapnia primarily by increasing tidal volume changes. Further, HG induced an increase in expiratory time (Te) that was abolished during hypercapnia but remained present during hypoxia with no changes in inspiratory time (TI). The TI:TE ratio increased in both hypercapnia and hypoxia, however, the magnitude of increase was only dependent on glycaemic state with hypercapnia.HG induces changes in baseline ventilation but also interacts with the response to a hypercapnic stimulus but not a hypoxic stimulus. The dependency on blood glucose levels of the TI:TE increase during hypercapnia may reflect the coordinated neuroendocrine responses seen during the counter‐regulatory response to HG and matching ventilation to an increased metabolic rate.Support or Funding InformationA. Mobley carried out this work in support of his MRes degree
Sensitizing Effects of Chronic Pretreatment with Tumor Necrosis Factor Alpha on Vagal Pulmonary Afferent Sensitivity in Mice
Authors: Lin Ruei‐Lung , Lee Lu‐Yuan 
Published: November 2023

Tumor necrosis factor alpha (TNFα), a pro‐inflammatory cytokine, is known to play an important role in the pathogenesis of allergic asthma. Inhalation of TNFα can also induce airway hyperresponsiveness in healthy human subjects, but underlying mechanisms are not fully understood. A recent study in our lab has demonstrated that TNFα pretreatment induced airway inflammation and a sustained elevation of pulmonary chemoreflex sensitivity (JAP 114: 1536–43, 2013), suggesting a possible involvement of pulmonary C‐fibers, but the direct evidence is lacking. The present study investigated the effects of chronic pretreatment with TNFα on the sensitivity of vagal pulmonary afferents in anesthetized open‐chest mice, using the single‐fiber recording technique. TNFα (10 μg/kg) and vehicle were administered by intra‐tracheal instillation in treated (TNF) and control (Veh) groups, respectively. Our results showed: 1) The peak activity of pulmonary C‐fibers to a bolus right‐atrial injection of capsaicin (Cap; 0.5 μg/kg) was significantly greater in TNF group (6.52 ± 1.34 impulses/s, n=10) than Veh group (2.10 ± 0.56 impulses/s, n=12; p<0.05). 2) The same dose of Cap evoked a burst of discharge (2.44 ± 0.71 impulses/s, n=8) in 75% (6/8) of rapidly adapting receptors (RARs) studied in TNF group, but did not stimulate any of the RARs (0/9) in Veh group. 3) This sensitizing effect of TNFα was further demonstrated in the enhanced response of Ca2+ influx to Cap in isolated vagal pulmonary sensory neurons using the Ca2+ imaging technique, and this effect was completely absent in the mice lacking both TNF receptors (p55/p75‐null mice). In conclusion, chronic pretreatment with TNFα induced a sensitizing effect on the Cap sensitivity in both pulmonary C‐fibers and RARs, and the action was mediated through TNF receptors. These sensitizing effects of TNFα may contribute, at least in part, to the pathogenesis of airway hyperresponsiveness induced by this cytokine.Support or Funding InformationSupported by NIH grants HL‐96914 and UL1TR0000117
Inhibition of Equilibrative Nucleoside Transporters Attenuated Pseudomonas Aeruginosa‐Induced Acute Lung Injury
Authors: Chambers Eboni , Borgas Diana , Blackburn Michael , Rounds Sharon , Lu Qing 
Published: November 2023

RATIONALEAcute lung injury (ALI) and its more severe form, acute respiratory distress syndrome (ARDS), causes acute respiratory failure with 40% mortality. We and others have previously demonstrated that adenosine is increased during tissue injury and protects against ALI through activation of adenosine receptors. Pseudomonas aeruginosa infections possess high mortality due to antibiotic resistance and there is compounded risk for ALI in patients with compromised innate immunity. However, it is unknown whether altering adenosine signaling can prevent or treat P. aeruginosa‐induced ALI. Extracellular and intracellular adenosine concentrations are regulated by equilibrative nucleoside transporters (ENTs). We hypothesized that increased extracellular adenosine by inhibition of ENT1 attenuates P. aeruginosa‐induced ALI.METHODSTo determine the effects of inhibition of ENT1 on P. aeruginosa‐induced ALI, both ENT1 inhibitors and null mice were used. P. aeruginosa was given to mice via intratracheal instillation. To elucidate the mechanism that underlies the effects of ENT1 inhibition on P. aeruginosa‐induced ALI, both agonists and antagonists directed against adenosine receptors A2AR and A2BR were used.RESULTSP. aeruginosa caused ALI in C57BL/6 mice in a dose dependent manner. Pharmacological inhibition of ENT1 by NBTI significantly attenuated P. aeruginosa‐induced ALI, as assessed by wet‐to‐dry lung weight, bronchoalveolar lavage (BAL) protein levels, BAL inflammatory cells and cytokine expression. This protective effect of NBTI was abolished when mice received an antagonist against either A2AR or A2BR. Additionally, agonists against A2AR or A2BR mimics NBTI blunting P. aeruginosa‐induced ALI. These results suggest that NBTI protects against P. aeruginosa‐induced ALI via adenosine‐mediated activation of both A2AR and A2BR. Interestingly, ENT1 null mice did not protect against P. aeruginosa‐induced ALI, suggesting an involvement of a compensatory mechanism.CONCLUSIONInhibition of nucleoside transporters may be a novel approach to prevent and treat P. aeruginosa‐ induced ALI.Support or Funding InformationThis work was in part supported by NIGMS P20GM103652 to S. Rounds and Q. Lu, VA Merit Review to S. Rounds, ATS/PHA research grant to Q. Lu, and NIEHS T32 ES007272 to E. Chambers.
Toll‐like Receptor 7 on Airway Nerves Causes Bronchodilation
Authors: Drake Matthew Georgenson , Proskocil Becky J , Lebold Katherine , Blum Emily , Fryer Allison , Jacoby David 
Published: November 2023

BACKGROUNDToll‐like receptor 7 (TLR7) detects viral single‐stranded RNA and triggers an innate immune response. We found that TLR7 agonists also induce a rapid and potent bronchodilation in the lung.OBJECTIVETo evaluate TLR7 expression and function in the lung.METHODSTLR7 expression was evaluated in lungs of Hartley guinea pigs and human trachea and primary bronchi (from deceased donors) using immunohistochemistry and RT‐PCR. TLR7's effect on bronchoconstriction was assessed using an organ bath system. Airways were contracted with methacholine (3 μM) and treated with TLR7 agonist R837 (10–300 μM). Some airways were pre‐treated with nitric oxide synthase inhibitor (L‐NMMA) or TLR7 antagonist IRS661. To differentiate the role of specific TLR7‐expressing airway nerve subtypes, some airways were cultured with or without attached sensory nerve ganglia for 48 hours prior to physiology experiments.RESULTSAirway parasympathetic nerves, and sensory nerves that originate in in the nodose, jugular, dorsal root and esophageal ganglia all express TLR7. TLR7 agonist rapidly dilated pre‐contracted human and guinea pig airways. TLR7‐mediated bronchodilation was blocked by TLR7 antagonist and by inhibition of nitric oxide production. Bronchodilation was unchanged in airways whose sensory nerves had undergone degeneration, suggesting parasympathetic nerves alone are sufficient for TLR7‐induced bronchodilation.CONCLUSIONSTLR7 is expressed by airway parasympathetic and sensory nerves. TLR7 mediates a rapid and potent bronchodilation. These data suggest that TLR7 is a potential bronchodilatory therapeutic target in humans.Support or Funding InformationFunding Source: This project was supported by NIH grants HL121254, HL124165, HL113023, AR061567.
Cyclic AMP pathways leading to immediate‐early gene activation in neuroendocrine cells: relevance to neurotransmitter signaling through the D1 dopamine and PAC1 neuropeptide receptors
Authors: Eiden Lee E , Elkahloun Abdel , Samal Babru B , Eiden Maribeth V , Emery Andrew C 
Published: November 2023

Gs‐coupled GPCR signaling in the NS‐1 pheochromocytoma cell line leads to the activation of three distinct cyclic AMP sensors, Epac, PKA and NCS/Rapgef2 mediate distinct cellular outputs: p38‐dependent growth arrest; CREB‐dependent cell survival and neuron‐specific gene expression; and ERK‐dependent neuritogenesis, respectively (Emery et al., Sci. Sig. 6: ra51, 2013; Emery et al., JBC 289: 10126, 2014). Expression of D1 dopamine receptors from a stably‐integrated, CMV promoter‐driven expression cassette in NS‐1 cells causes cyclic AMP elevation and activation of all three of these pathways, leading to D1 receptor‐dependent activation of all three downstream pathways, as previously reported for activation of the endogenous PAC1hop receptor by the neuropeptide PACAP. To investigate which of the three pathways might mediate cAMP‐dependent immediate‐early gene (IEG) transcription relevant to neurotransmitter action in vivo, we examined genome‐wide transcriptional regulation by cyclic AMP in NS‐1 cells, using microarray analysis. Treatment of NS‐1 cells for one hour with the cell‐permeant cyclic AMP analog 8‐CPT‐cAMP (100 micromolar), an equipotent activator of Epac2, PKA and NCS/Rapgef2 (Emery et al., JBC 289: 10126, 2014) resulted in significant up‐regulation of 174 mRNAs. Of these, ten encoded transcription factors, and six of these encoded IEGs: Ier‐3/Egr3, Zif268/Egr1, Nr4a1, Nr4a3, c‐Fos, and JunB. Cyclic AMP‐dependent up‐regulation of the Ier‐3/Egr2 and Zig268/Egr1 genes, but not the Nr1a1, Nr4a3, or JunB genes, was ERK‐dependent (blocked by the MEK inhibitor U0126, at 10 micromolar), while up‐regulation of the c‐Fos gene appeared to be partially ERK‐dependent. These results suggest that regulation of IEG expression by D1 and PAC1 receptor stimulation may involve two cAMP‐dependent pathways, one mediated by NCS/Rapgef2, and the other by either Epac or PKA. These novel signaling pathways may be relevant to IEG regulation by dopamine in the striatum in vivo (Gerfen et al., J. Neurosci. 15: 8167, 1995) and by the stress‐regulatory neuropeptide PACAP in hypothalamus and extended amygdala (Stroth and Eiden, Neuroscience 165: 1025, 2010; Emery and Eiden, FASEB J. 26: 3199, 2012).Support or Funding InformationSupported by NIMH‐IRP project ZO1‐MH002386
Role of neuronal signaling effector hydrogen sulfide (H2S) and sulfhydration in Huntington's disease
Authors: Paul Bindu Diana , Snyder Solomon H. 
Published: November 2023

Hydrogen sulfide (H2S) has joined the ranks of the gasotransmitters, nitric oxide and carbon monoxide as a signaling molecule that modulates a wide spectrum of physiological processes. H2S signals via sulfhydration, wherein it mediates the conversion of −SH groups of reactive cysteine residues on target proteins to −SSH or persulfide groups. H2S is synthesized by cystathionine gamma lyase (CSE), cystathionine beta synthase (CBS) and 3‐mercaptopyruvate sulfurtransferase of the reverse transsulfuration pathway. Aberrant H2S metabolism is involved in the progressive neurodegeneration seen in Huntington's disease (HD). HD is a devastating condition and is currently considered to be an incurable disease of the nervous system. New treatment options are highly sought after. We asked how normal healthy neural development is influenced by the differential interplay of huntingtin versus mutant huntingtin (mHtt) function vis‐à‐vis CSE and CBS action in the nervous system. Specifically, we sought to understand how the modalities of mutant transformation of huntingtin at the genetic and epigenetic levels affect mHtt effects on H2S action. We chose cell culture and mouse models of HD to study their manifestation on the progressive neurodegeneration observed alongside the cognitive and motor deficits that are characteristic of human HD patients. We have shown that loss of CSE mediates neurodegeneration and disease progression in HD. It appears that the neuronal redox effector functions of H2S are differentially modulated by the action of mHtt on CSE and CBS thereby affecting disease progression in HD by variable regulatory mechanisms.Representative Recognition/HonorASBMB/jbc Herbert Tabor Young Investigator Award (May 2015) at the third European Conference on the Biology of Hydrogen Sulfide at Athens, Greece.Support or Funding InformationUnited States Public Health Service Grant MH18501 to S.H.S, CHDI Foundation
Cardiomyocyte Ogt limits ventricular dysfunction in mice following pressure overload without affecting hypertrophy
Authors: Dassanayaka Sujith , Brainard Robert E , Watson Lewis J , Long Bethany W , Brittian Kenneth R , DeMartino Angelica M , Aird Allison L , Kilfoil Peter J , Muthusamy Senthilkumar , Hamid Tariq , Prabhu Sumanth D , Jones Steven P 
Published: November 2023

The myocardial response to pressure overload involves coordination of multiple transcriptional, posttranscriptional, and metabolic cues. Previous studies show that one such metabolic cue, O‐linked beta‐N‐acetylglucosamine (O‐GlcNAc), is elevated in the pressure‐overloaded heart, and the increase in O‐GlcNAcylation is required for cardiomyocyte hypertrophy in vitro. Yet, it is not clear whether and how O‐GlcNAcylation participates in the hypertrophic response in vivo. Here, we addressed this question using patient samples and a preclinical model of heart failure. Protein O‐GlcNAcylation levels were increased in myocardial tissue from heart failure patients compared with normal patients. To test the role of O‐GlcNAc transferase (OGT) in the heart, we subjected cardiomyocyte‐specific, inducibly deficient Ogt (i‐cmOgt−/−) mice and Ogt competent littermate wild type (WT) mice to transverse aortic constriction (TAC). Deletion of cardiomyocyte Ogt significantly decreased O‐GlcNAcylation and exacerbated ventricular dysfunction, without producing widespread changes in metabolic transcripts. Although some changes in hypertrophic (elevated Nppa, reduction in GATA4) and fibrotic signaling (elevated Tgfb2, reduction in Fgf2) were noted, there were no histological differences in hypertrophy or fibrosis. We next determined whether significant differences were present in i‐cmOgt−/− cardiomyocytes from surgically‐naïve mice. Interestingly, markers of cardiomyocyte dedifferentiation (Acta2, Nkx 2–5) were elevated in Ogt deficient cardiomyocytes. Although no significant differences in cardiac dysfunction were apparent after recombination, it is possible that such changes in dedifferentiation markers could reflect a larger phenotypic shift within the Ogt deficient cardiomyocytes. We conclude that cardiomyocyte Ogt is not required for cardiomyocyte hypertrophy in vivo; however, loss of Ogt may exert subtle phenotypic differences in cardiomyocytes that sensitize the heart to pressure overload‐induced ventricular dysfunction. Because diabetes is often associated with altered O‐GlcNAcylation, our findings could have implications for the diabetic heart.Support or Funding InformationDr. Jones has been supported by grants from the NIH (R01 HL083320, R01 HL094419, P20 RR103492, and P01 HL078825). Mr. Dassanayaka holds an American Heart Association Predoctoral Fellowship – Great Rivers Affiliate (14PRE19710015).