bluuebunny/crossref_metadata_2025_split huggingface dataset:
Induction of intestinal P‐glycoprotein (Pgp) expression and activity by sub‐toxic doses of acetaminophen (AP) in rat intestine and human LS174T cells
Authors: Ghanem Carolina Inés , Arias Agostina , Villanueva Silvina , Novak Analia , Filia María Fernanda , Dellicarpini Griselda , Marín José Juan Garcia , Mottino Aldo Domingo , Rubio Modesto Carlos 
Published: June 2021

AP induced liver Pgp expression and activity in rats.Aimto study the effect of sub‐toxic doses of AP on intestinal Pgp expression in rats and in a human intestinal cell line.M&MMale Wistar rats were injected i.p. for 3 days with 0.2; 0.3; and 0.6 g/kg b.w. of AP (AP group) or vehicle (C group) (n=4). One day later Pgp expression and activity were evaluated by western‐blotting and rhodamine 123 (R123, 15 uM) serosal to mucosal transport in ileum isolated sacs with or without verapamil (V, 100 uM). Intestinal human LS174T cells were exposed to a sub‐toxic dose of AP (5 mM) for 48 hs, then Pgp expression was evaluated by QPCR and R123 efflux was determined by flow citometry with or without V.ResultsIleum Pgp expression increased in AP vs C (160%, P<0.05). Cumulative R123 secretion was 44% higher in AP group (P<0.05). V inhibited R123 transport in both AP and C. Cells exposed to AP expressed 60% more protein and presented 80% more activity than control cells (P<0.05).ConclusionSub‐toxic doses of AP induced intestinal Pgp expression and activity in rats and in a human intestinal cell line. This suggests potential drug‐drug interactions when AP is co‐administered with other Pgp substrates. Consistently, preliminary studies have shown induction of Pgp in a human intestinal cell line exposed to sub‐toxic concentrations of APAP.
Epigenetic Modifications Of Histones Play A Critical Role In Ethanol‐Mediated Enhancement Of FasL Gene Expression And Cell Death In CD4+ T Lymphocytes
Authors: Ghare Smita , Patil Madhuvanti , Joshi‐Barve Swati , McClain Craig , Barve Shirish 
Published: June 2021

Alcohol abuse is known to induce immunosuppression involving the depletion of CD4+ T cells; however the mechanisms underlying this alcohol effect are not clearly understood. Recent work from our laboratory showed that ethanol decreases S‐adenosylmethionine (SAM) levels and enhances activation‐induced apoptotic cell death (AICD) in CD4+ T cells. SAM is a critical methyl donor and impacts epigenetic variations involving histone modifications which play a key role in altering chromatin structure and transcriptional activity. Accordingly, the present work was carried out to investigate the immunotoxic effects of ethanol by examining FasL promoter histone modifications in the regulation of FasL gene expression in CD4+ T lymphocytes exposed to alcohol.Examination of the FasL promoter in CD4+ T cells exposed to ethanol showed increased histone H3 acetylation which is associated with active transcription. In correspondence with increased histone acetylation ethanol was observed to recruit the histone acetyltransferase and transcriptional co‐activator p300. Notably, the histone modifications induced by ethanol enhanced NFAT transcription factor binding and correlated with increased FasL expression. These data strongly support the notion that epigenetic modifications involving histones are critical in ethanol‐induced FasL expression and AICD in CD4+ T cells and ensuing immunosuppression.
Eating a high fat chow differentially affects sensitivity of adolescent and adult male rats to cocaine‐induced locomotor activity
Authors: Baladi Michelle G , McGuire Blaine A , France Charles P 
Published: June 2021

Dopamine (DA) systems are the target of many drugs of abuse (e.g. cocaine). Many factors, such as age and feeding condition, can alter the behavioral effects of drugs acting on DA systems. For example, adolescent rats are more sensitive than adult rats and food‐restricted rats are more sensitive than free‐feeding rats to some behavioral effects of cocaine; however, much less is known about other dietary manipulations (e.g. high fat diet) on the effects of cocaine. This study examined how access to a high fat chow during adolescence or adulthood impacts sensitivity to the locomotor effects of cocaine. Separate groups of adolescent and adult male Sprague Dawley rats (PND 25 or 85, respectively) had free access to a standard chow (4.4% fat) or to a high fat chow (34.3% fat), or restricted access to a high fat chow (body weight matched to rats eating a standard chow). Regardless of whether adolescent rats had free or restricted access, eating a high fat chow significantly increased sensitivity to cocaine, compared to the effects of cocaine in adolescent rats with free access to a standard chow and compared to adult rats regardless of diet. Thus, adolescence might represent a critical period when feeding conditions influence sensitivity to, and possibly vulnerability to abuse, cocaine or other related drugs.This work is supported by Senior Scientist Award DA17918.
Thrombin mediated PAR1 stimulation results in sustained activation of Rap1 and downstream responses in human 1321N1 astroglioma cells
Authors: Sayyah Jacqueline , Nogal Nekeisha , Dusaban Stephanie , Brown Joan Heller 
Published: June 2021

G‐protein coupled receptors that activate RhoA can lead to aberrant cell growth and have been linked to human diseases including cancer. We have shown that in 1321N1 astroglioma cells, stimulation of the PAR1 receptor with thrombin activates RhoA and downstream signals required for mitogenesis. One mediator of thrombin induced mitogenesis is the matricellular protein CCN1 which signals through integrins (Walsh, FASEB J, 2008) and another is phospholipase C epsilon (Citro et al PNAS, 2007). Integrin signaling requires the low molecular weight GTPase Rap1, and PLC epsilon serves as an activator or Rap1. Accordingly we asked whether stimulation of the G12/13 and RhoA coupled PAR1 receptor in 1321N1 cells was coupled to activation of Rap1. Using a pull down assay to assess GTP liganded Rap1, we find that thrombin elicits a robust and sustained increase in Rap1 activation, increasing to 3 fold basal levels and maintained for at least 6 hours. Thrombin stimulation also elicits 4–5 fold increases ERK1/2 and PKD activation which are sustained for at least 6 hours. Our results suggest that thrombin mediated Rap1 activation is associated with sustained ERK1/2 and PKD activation. We are currently exploring the possibility of involvement of RhoA and PLC epsilon in thrombin induced Rap1 activation and the role of Rap1 in sustained ERK and PKD activation induced by thrombin in 1321N1 astroglioma cells.Supported by NIH grant, GM 36927
Functional selectivity at the serotonin 2A receptor: differential signaling by serotonin and dimethylated tryptamines
Authors: Schmid Cullen L , Bohn Laura M 
Published: June 2021

Serotonin and the hallucinogenic metabolites of tryptamines, dimethylated tryptamines, activate the serotonin 2A receptor (5‐HT2AR), which is implicated in numerous mental health disorders. We have previously demonstrated that the 5‐HT2AR is differentially regulated by βarrestin2 (βarr2) depending upon the agonist; here we utilized βarr2 knockout mice to compare signaling profiles in vivo, by assessing the head twitch response (which serves as a behavioral model for selective 5‐HT2AR activation), and in vitro, by assessing kinase activation. We demonstrate that serotonin leads to 5‐HT2AR‐mediated phosphorylation of the serine/threonine kinase AKT in the mouse frontal cortex and in primary neuronal cultures and that the head twitch response occurs in a βarr2 and AKT dependent manner. In contrast, a metabolism‐resistant dimethylated tryptamine, 5‐MeO‐DMT, does not induce phosphorylation of AKT in frontal cortex or in cortical neurons and induces the head twitch response regardless of βarr2 or inhibition of AKT expression. We also show that in the absence of βarr2, the head twitch response is enhanced in response to 5‐MeO‐DMT, suggesting that while βarr2 mediates serotonin signaling at the 5‐HT2AR, it dampens dimethylated tryptamine signaling at this receptor.Funding: R01 DA025158, NIDA.
Gene expression profiling of G‐protein coupled receptors in human urothelial cell lines
Authors: Ochodnicky Peter , Humphreys Sian , Eccles Rachel , Poljakovic Mirjana , Wiklund Peter , Michel Martin C. 
Published: June 2021

Urothelium contributes to the regulation of urinary bladder function and hence could be a novel drug target for bladder dysfunction. As fresh human urothelium may be difficult to obtain, urothelium‐derived cell lines may represent an alternative but they need to be validated. By Real‐time PCR array, we have compared the pattern of expression of >40 G protein coupled receptors (GPCRs) in UROtsa (immortalized non‐malignant cell line used in a differentiated and non‐differentiated state), J82 (urothelium‐derived cancer cell line) and native human urothelium (obtained post‐mortem). Native urothelium expressed a wide range of GPCRs including muscarinic M2 to M5, angiotensin AT1, all subtypes of adrenergic, bradykinin, endothelin, cannabinoid, sphingosine‐1‐phosphate and tachykinin receptors. Neither UROtsa (regardless the differentiation state) nor J82 cells mimicked this expression pattern, reflecting down‐regulation or complete loss of expression of GPCRs in most cases. In conclusion, human urothelium expresses many GPCRs, indicating that multiple mechanisms could regulate urothelial function. However, use of UROtsa and J82 cells as model systems needs to be carefully validated for each specific research question.This work was supported through Coordination Theme 1 (Health) of the European Community's FP7, HEALTH‐F2‐2008‐223234.
Development of a novel nasal vaccine using a claudin‐4 binder
Authors: Suzuki Hidehiko , Kondoh Masuo , Kakutani Hideki , Hamakubo Takao , Watari Akihiro , Yagi Kiyohito 
Published: June 2021

Mucosal vaccine elicits both mucosal and systemic immune responses, resulting in the prevention of infection and the elimination of pathological cells. Moreover, mucosal administration is needle‐free, less painful, and has improved patient compliance. Thus, mucosal vaccination appears to be an ideal vaccination strategy, although mucosally administered protein antigens are poorly immunogenic. The effective delivery of antigens to mucosa‐associated lymphoid tissues (MALT) is needed for the development of a potent mucosal vaccine. A single layer of epithelial cell sheet, follicle‐associated epithelium (FAE), covers MALT, and claudin‐4, a component of tight junctions, is expressed in FAE. These findings indicate that a claudin‐4‐targeting system may be a promising mucosal vaccine; however, the claudin‐4‐targeted mucosal vaccine has never been developed.We previously found that a C‐terminal fragment of Clostridium perfringens enterotoxin (C‐CPE) is a claudin‐4 ligand. In the present study, we investigated whether a claudin‐4‐targeting is a potent method to develop mucosal vaccine using C‐CPE and ovalbumin (OVA) as a model antigen, and we found that nasal immunization with C‐CPE‐fused OVA activated Th1 and Th2 immune responses and deletion of claudin‐4‐binding region attenuated the activation. This is the first report to indicate that a claudin‐4 targeting may be a promising mucosal vaccine.
Alkaloids of Borreria verticillata mediate hypotensive activity through muscarinic, M3 receptor, a stimulatory release of nitric oxide (NO)
Authors: Moodie‐Henry Bridgette Josephine , West Manley E , Gossel‐Williams Maxine Deborah 
Published: June 2021

Chemical analysis of Borreria verticillata produced a primary (BV1) and a quaternary (BV2) alkaloidal extracts. The objective was to investigate pharmacological activities of these extracts on Sprague‐Dawley rat blood pressure and isolated aortic rings.Mature rats anaesthetized with 15% urethane (0.8 mL/100 g body weight) and the femoral vein cannulated for intravenous administration. The carotid artery, cannulated for blood pressure measurements which were recorded using a pressure transducer attached to a Grass polygraph. Isolated aortic rings placed separately in an organ bath system in Kreb's physiological solution kept at 37 °C, aerated with CO2: O2 (5%: 95%). Isometric tensions, measured with FT3 force transducer connected to a Polyview. BV1 (≤31.12 mg/mL) and BV2 (≤41.84 mg/mL) produced a fall in blood pressure which was inhibited by atropine (0.05 μg/mL). BV2 and BV1 (≤0.96 mg/mL) however, inhibited phenylephrine (PE – 2.3 μg) induced contractions on the aortic rings. Acetylcholine (ACH ≤ 0.27μg/mL), used comparatively, responded similarly. The effects were blocked by L‐NAME (0.02 μg). Results showed that the extracts have hypotensive activity which may be mediated through muscarinic M3 receptors, stimulating the release of nitric oxide from vascular endothelium. These extracts may have therapeutic usefulness. Further studies are being done to elucidate more detailed mechanism of action.
Synthesis, biological and structural characterization of novel glycopeptide analogs of nociceptin
Authors: Rodriguez Raquel E. , Gonzalez‐Nuñez Veronica , Barreto‐Valer Katerine , Mayato Carlos , Dorta Rosa L. , Trujillo‐Vazquez Jesus , Jimenez‐Barbero Jesus , Calle Luis , Marcelo Filipa , Morando Maria , Rosa Monica , Arsequell Gemma , Valencia Gregorio 
Published: June 2021

Polysaccharides are known to module the native conformation and stability of large globular proteins in many biological systems. Similar effects leading to drastic changes on biological activity can always be observed when simple carbohidrates are chemically bound to small peptide ligands. Opioid peptides are a good exam¬ple of dramatic activity potentiation by glicosidation. To inves¬tigate if similar phenomena take place on the opioid receptor like (ORL) ligand, nociceptin, four glycopeptide analogs of this heptadecapetide have been synthesized. Thus, an O alfa D GalNAc and a O beta D GlcNAc on Ser10, an O alfa D GalNAc on Thr5 and a Lac on (Ser Thr) substituted nociceptin analogues, were prepared. Their binding affinity for the ORL have been determined on HEK‐293 cells stably expressing the zefrafish ORL receptor. Moreover, their solution conformation has been studied by circular dicro¬ism, NMR spectroscopy and molecular mechanics and dynamics calcu¬lations. A discussion of activity conformation relationships features on this glycopeptides will be presented.This research was supported by LA MARATO TV3 from the Regional Government of Cataluña.
Contrasting properties of VEGF165 and VEGF165b splicing isoforms on glomerular water permeability in transgenic mice and complementary rescue of the phenotype
Authors: Oltean Sebastian , Ferguson Joanne , Qiu Yan , Salmon Andrew H , Quaggin Susan , Harper Steve J , Bates David O 
Published: June 2021

VEGF is a major regulator of vascular permeability and increases glomerular permeability to water (LPA/Vi) in vitro on isolated intact glomeruli (1). In a double‐transgenic mouse model of kidney‐specific inducible VEGF expression a time‐dependent increase in LPA/Vi in double‐transgenic animals treated with Doxycycline compared with wild‐type mice was observed. VEGF165b, a splicing variant resulting from the use of a tandem 3' splice site in exon 8 of the VEGF gene, differs in six amino acids at the C‐terminal end of VEGF. VEGF165b decreases glomerular permeability to water both in vitro as well as in vivo in a transgenic mouse model of VEGF165b over‐expression in kidneys.To determine whether the decreased glomerular permeability phenotype in mice over‐expressing VEGF165b can be rescued by VEGF, paired permeability measurements were performed on glomeruli isolated from heterozygote mice before and after incubation in 1nM rhVEGF for 60 minutes. There was a significant increase in LPA/Vi from 1.67±0.32 to 2.57±0.58, indicating that the decreased permeability in VEGF165b expressing mice is reversible.
Overexpression of VEGF165b in mouse ovary results in reduced litter size
Authors: Qiu Yan , Murphy David , Harper Steven J. , Bates David O. 
Published: June 2021

Angiogenesis in the ovary facilitates oxygen, nutrient and hormone delivery. VEGF, which plays a key role in regulation of ovarian follicle development, is differentially spliced in the terminal exon to form two families of proteins, VEGFxxx (angiogenic) and VEGFxxxb (anti‐angiogenic). To identify the function of VEGF165b in the ovary, nine female transgenic mice (TG) overexpressing VEGF165b under the control of the MMTV promoter and 10 wild type (WT) female littermates were mated with WT mice. RT‐PCR and immunohistochemistry indicated strong expression of VEGF165b in ovaries of TG females. TG mothers produced litters of half the size of WT dams (3.3±0.4 vs. 5.8±0.7 pups/litter), or TG males (6.1±0.7 pups/litter). There was no developmental defect identified in either the WT or TG pups from TG mothers. The number of embryos released into oviducts by TG females were reduced to 82±6% of control mice. 38.5% of TG females had embryos lacked the Cumulus Cell‐Oocyte Complex, while none from WT females. Overexpression of VEGF165b appears to reduce fertility, possibly by its anti‐angiogenic actions on follicular development.Supported by the Wellcome Trust and British Heart Foundation.
Myocardial material parameter estimation from in‐vivo myocardial strain measurements
Authors: Villongco Christopher Tirona , Covell James W. , Omens Jeffrey H. , McCulloch Andrew D. , Kerckhoffs Roy C. P. 
Published: June 2021

The aim of this study was to develop and test a new method to estimate myocardial material parameters from 3‐D strains measured in individual canine hearts. The method can also be applied with non‐invasive imaging modalities.Diastolic myocardial 3‐D finite deformations were obtained in open‐chest anesthetized dog hearts by tracking the positions of implanted bead sets in the left ventricular free wall using biplane x‐ray cineradiography. Anatomically detailed finite element models of individual canine hearts were fitted to MR and CT images of perfusion‐fixed hearts.Resting myocardial material parameters were estimated by minimizing the differences between ventricular deformations predicted by the model and those measured in the intact heart using a Levenberg Marquardt nonlinear least‐squares optimization scheme. Artificially generated strains were used to confirm convergence to correct parameters in less than 20 iterations. Noisy artificial data with a realistic measurement error of 0.01 cm resulted in normally distributed parameter solutions, with respective means within 3% of true values. The means of the strains predicted by a model at marker locations with the noisy parameters had an average error of −1.2% ± 4.1% of the true strains. The best estimate of the material properties optimized by the real anatomic model and data are validated by subsequent comparison to experimental and published data.
Oscillatory fluid shear stress‐induced JNK activation via NADPH oxidase implicates mitochondrial superoxide production in endothelial cells
Authors: Jen Nelson , Takabe Wakako , Li Rongsong , Ai Lisong , Hsiai Tzung K. 
Published: June 2021

Oscillatory fluid shear stress (OSS) increases vascular oxidative stress and induces endothelial cell dysfunction. In our previous study, we demonstrated that OSS induced superoxide generation via activation of NADPH oxidase enzyme system. In this study, we examined the effect of OSS on mitochondrial dysfunction. Using chemical inhibitors against NADPH oxidase (Apocynin) and JNK (SP600125), we demonstrated that OSS induced JNK activation via NADPH oxidase in bovine aortic endothelial cells (BAEC). JNK activation peaked at 1h following treatment of OSS (±3dyn/cm2) by western blot analysis. Apocynin inhibited this induction and also inhibited OSS‐induced superoxide generation measured by dihydroethidium. We then examined the role of JNK activation in OSS‐induced mtO2·− production by using MitoSox Red dye specific for mtO2·−. We found that SP600125 inhibited ·− production as quantified by flow cytometry. OSS‐stimulated mtO2 Our data suggests that OSS‐activated NADPH oxidase induces intra‐cellular superoxide production and activates JNK, which in turn induces mtO2·− production..This study is supported by NIH HL083015 and HL091302.
Alterations to the Liver RAS in Antenatal Induced MLPD Systemic Hypertension
Authors: Stewart John Michael , Goyal Ravi , Longo Lawrence 
Published: June 2021

ObjectiveIt has been well established that systemic hypertension can be result of fetal programming by antenatal maternal low protein diet (MLPD). Furthermore, as apposed to the ‘classical’ systemic renin‐angiotensinogen system (RAS) several studies have suggested that many tissues including lungs, pancreas, kidney, brain, and liver have their own ‘alternative’ RAS. In mice, we tested the hypothesis that hypertensive mice resulting from antenatal MLPD show changes in the liver specific RAS pathway.MethodsMice dams were fed a specified isocaloric low protein diet from 7 days precoitus maintained thoughout gestation. We isolated DNA, mRNA, and protein from livers of offspring female and male mice exposed to 50% MLPD and 33% MLPD at 3 weeks and 33 weeks of age. We examined eight RAS genes with qPCR and dot blot analysis at the transcript and protein level.ResultsAGT transcript levels were altered in MLPD mice while there was no significant change in protein. Female AGT transcripts were increased at 3 weeks of age but not 33 weeks and protein levels were not significantly different from control.ConclusionsIn response to an antenatal maternal low protein diet AGT transcript levels change while protein levels do not. These changes in liver RAS, may help elucidate mechanisms responsible for fetal programming of disease, especially increased blood pressure.
A Dual Role of Cyclic GMP in Cardiac Survival Signaling
Authors: Lee SungRyul , McIntosh Rachel , Shen Xinagjun , Chanoit Guillaume , Zvara David A , Xu Zhelong 
Published: June 2021

Cyclic guanosine 3′5′‐monophosphate (cGMP) plays an important role in cardioprotection against ischemia/reperfusion injury through activation of protein kinase G (PKG). The purpose of this study was to determine the impacts of cGMP on cardiac survival signaling pathways. We found that cGMP prevents the mitochondrial permeability transition pore (mPTP) opening by inactivating glycogen synthase kinase 3â (GSK‐3â) via protein kinase G (PKG) in cardiac H9c2 cells. Although Akt is well known as an important upstream regulator of GSK‐3â and its activation leads to inactivation of GSK‐3â, we found that cGMP negatively regulated Akt activity. We further found that the negative regulatory effect of cGMP on Akt activity is mediated by the protein phosphatase PP2A but not by PKG. While GSK‐3â and Akt are critical for acute cardioprotection, an excessive activation of Akt or GSK‐3â inactivation can also result in cardiac hypertrophy. Therefore, the negative effect of cGMP on Akt activity may serve as an important mechanism leading to prevention of hypertrophy. Taken together, cGMP not only inactivates GSK‐3â through PKG (this leads to acute cardioprotection) but also negatively regulates Akt activity (this may lead to prevention of hypertrophy and heart failure) in cardiac cells. We propose that cGMP is a versatile signal with a dual beneficial role in cardiac survival.This study was supported by NIHR01HL08336