bluuebunny/crossref_metadata_2025_split huggingface dataset:
Six sigma Quality Metrics to evaluate Selenium, Zinc and Iron data
Authors: Castanheira Isabel Palmira , Gueifão Sandra Isabel , Coelho Inês Alexandra , Matos Ana Sofia 
Published: June 2021

Identifying the most signification sources of artificial differences in clinical and food data quality is essential for those involved, in estimating and comparing nutrient intake based on data from different sources.In this work six sigma methodology and metrics are applied to food composition data and clinical data to evaluate selenium, zinc and iron data quality. Trace elements in fish, milk and in serum were plotted in method device charts using maximum tolerances applicable to food composition organizations with acceptance criteria defined by USDA and Clinical Laboratory Improvement Amendments requirements which have been tabulated by the USA Federal Government.The approach was applied directly on laboratory data obtained for determination of selenium zinc and iron content in fish milk and serum. The Measurement Device Chart was constructed by representing the allowable inaccuracy and allowable imprecision of each programme. With the same methodology and using the definition of separate quality rules (tolerance limits) that are accepted in food and in clinical analysis, it was possible to compare and measure the quality of both types of data.This information could enable users of food data to identify values that have acceptable quality for use in evaluation of relationships between food intake and chronic diseases, for example in multicenter epidemiological studies.Grant Funding Source: EuroFIR
The role of histamine H1, H2 and H3 receptors in the stimulation of NT‐3 synthesis in astrocytes
Authors: Carman‐Krzan Marija , Mele Tina , Juric Damijana Mojca 
Published: June 2021

Neurotrophin‐3 (NT‐3) is produced by astrocytes, in addition to neurons, and monoamine neurotransmitters play a role in controlling NT‐3 synthesis. We evaluated the active involvement of histamine receptors and intracellular mechanisms in the regulation of NT‐3 production by HA.HA (1 μM) significantly and transiently elevated NT‐3 mRNA levels by 2.2‐fold after 30 min of incubation following by 2.1‐fold increase in NT‐3 intracellular levels after 6 h. Its stimulation was partly inhibited by selective H1, H2 and H3 antagonists. NT‐3 levels in astrocytes were increased by selective H1, H2 and H3 agonists as well as by adenylyl cyclase activation, PKA activation, PKC activation and mobilization of intracellular Ca2+. HA‐induced increase in NT‐3 cellular levels were significantly reduced by H‐89, staurosporin, KN‐62 and desensitizing pretreatment with TPA. MAP kinase cascade inhibitor PD98059 completely blocked the stimulatory action of HA and all selective agonists. Using quantitative RT‐PCR we confirmed that cultured rat cortical astrocytes express not only H1 and H2 receptors already identified by radioligand binding studies but also H3 receptors which were sensitive to pertussis toxin. In conclusion, the synthesis of astrocytic NT‐3 stimulated by HA is an adaptable process using several parallel histaminergic pathways using H1‐, H2‐, and H3‐receptor pathways. The observed H1, H2 and H3 receptor crosstalk in histaminergic regulation of NT‐3 leads to the convergence of these pathways at the level of MAP kinase activity which in the next step triggers the increased expression and subsequently the synthesis of NT‐3 in astrocytes.
Gαi binding sites on Calnuc and NUCB2 define a new family of structurally‐related Gαi‐regulatory motifs
Authors: Garcia‐Marcos Mikel , Kietrsunthorn Patrick , Wang HongHui , Ghosh Pradipta , Farquhar Marilyn G 
Published: June 2021

Heterotrimeric G proteins are molecular switches modulated by families of structurally and functionally related regulators. GIV is the first non‐receptor GEF that activates Gαi‐subunits via a defined, evolutionarily conserved motif. Here we found that Calnuc and its closely related homolog NUCB2, two calcium‐binding proteins, share a common motif with GIV for Gαi binding and activation. Bioinformatic searches and structural analysis revealed that Calnuc and NUCB2 possess an evolutionarily conserved motif with sequence and structural similarity to GIV's GEF sequence. Using in vitro pulldown and competition assays we demonstrate that this motif binds preferentially to the inactive conformation of Gαi1 and Gαi3 over other Gα‐subunits and docks onto the same site as GIV, i.e., the α3/Switch II cleft. Calnuc binding was impaired when K248 in the α3 helix of Gαi3 was replaced by the corresponding M residue in Gαo, which does not bind to Calnuc. Moreover, mutation of hydrophobic residues from the conserved motif predicted to dock on the α3/Switch II cleft of Gαi3 abolished Calnuc's binding to Gαi3 and impaired its GEF activity in vitro. We also demonstrate that calcium binding to Calnuc and NUCB2 abolishes their interaction with Gαi3, probably via a conformational change that renders their Gαi‐binding residues unexposed. Taken together our results define a new class of structurally‐related Gαi regulatory motifs and provide the structural basis for the properties of Calnuc and NUCB2 binding to Gα‐subunits and its regulation by calcium ions.Support: NIH grants DKI7780 and CA100768 to M.G.F. Susan G. Komen fellowship KG080079 to M.G‐M CAMS (BWF) and RSA (AGA) to P.G.
Regulation and Activation of Phospholipase Cβ
Authors: Lyon Angeline M. , Tesmer Valerie M. , Dhamsania Vishan , Gutierrez Joanne , Chowdhury Shoaib , Suddala Krishna , Northup John K. , Tesmer John J.G. 
Published: June 2021

Phospholipase Cβ (PLCβ), which catalyzes the hydrolysis of phosphatidylinositol‐4,5‐bisphosphate (PIP2) to the second messengers diacylglycerol (DAG) and inositol‐1,4,5‐triphosphate (IP3), is activated in response to specific extracellular stimuli through interactions with the heterotrimeric G protein Gαq. However, the structural and functional mechanisms underlying the regulation of PLCβ activity is poorly understood. In this work we present two new structures of PLCβ homologs purified from endogenous sources that include a highly conserved element from the C‐terminal regulatory domain. This conserved element forms a microdomain that interacts with a conserved surface of the catalytic core. Deletion of or mutation of residues within this microdomain in PLCβ3 results in increased PLCβ activity. Based on the recent structure of the Gαq‐PLCβ3 complex, this microdomain is likely displaced from the catalytic core upon Gαq binding. Thus, the C‐terminal microdomain appears to represent an autoinhibitory element that modulates the basal activity of PLCβ and is involved in allosteric changes mediated by Gαq.Support was provided by NIH grants HL086865 and HL071818.
Modulation of CGRP‐receptor function by G‐protein βγ subunits
Authors: Meens Merlijn JPMT , Mattheij Nadine JA , Spijkers Léon JA , Alewijnse Astrid E , De Mey Jo GR 
Published: June 2021

Activated CGRP–receptors (CGRP‐R) might relax vascular smooth muscle (VSM) via activation of Gsα and by inducing dissociation of endothelin‐1 (ET‐1) from ETA‐receptors (Meens et al. PLos ONE 2010). The latter “terminator effect” is not mimicked by other stimuli of Gsα. Thus, we analyzed roles of G‐protein βγ subunits (Gβγ) in CGRP‐R function. Organ chamber studies with rat arteries and radioligand binding studies on membranes from CHO cells expressing human CGRP‐R were performed. In several types of arteries, isoproterenol (ISO), forskolin and CGRP caused relaxation during K+‐induced contractions. The effects of CGRP did not correlate with those of ISO or forskolin. In mesenteric arteries, contracted with K+‐ or ET‐1, IBMX increased relaxations induced by sodium nitroprusside (SNP) or ISO, but not by CGRP. Gallein and M119 (Gβγ inhibitors), but not fluorescein (negative control), inhibited the relaxing effect and the “terminator effect” of CGRP while not altering arterial effects of i) K+, ii) ET‐1, iii) SNP or iv) ISO. Gallein did not displace [125I]‐CGRP from CGRP‐R but caused an acute fivefold increase of the Bmax for [125I]‐CGRP. In conclusion, activated CGRP‐R cause cyclic nucleotide‐independent relaxation of VSM and terminate arterial effects of ET‐1 via Gβγ. Also, Gβγ seems to restrict agonist‐binding to CGRP‐R.Performed within TIPharma. M119 was obtained from the National Cancer Institute (US).
Mercaptoethylguanidine Attenuates Caustic Esophageal Injury in Rats; A Role for Scavenging of Peroxynitrite
Authors: Guven Ahmet , UYSAL Bulent , CALISKAN Bahadir , OZTAS Emin , KORKMAZ Ahmet , OZTURK Haluk 
Published: June 2021

IntroductionAfter ingestion of caustic material, tissue damage is caused by reactive oxygen species and reactive nitrogen species. Mercaptoethylguanidine (MEG) is a scavenger of peroxynitrite. Thus, this study was designed whether MEG has a beneficial effect on caustic esophageal injury.Methods45 rats were allocated into 3 groups; sham‐operated, untreatment and treatment groups. Caustic esophageal burn was created by instilling 15% NaOH in the distal esophagus. The treatment group treated with 10 mg/kg/day MEG i.p. for 5 days. All rats were killed at 28 days. Efficacy of the treatment was assessed by histopathologically and biochemically.ResultsThe stenosis index and the histopathologic damage score were significantly lower in the MEG‐treatment group which showed a correlation with tissue hydroxyproline level. In the untreatment group, tissue oxidative stres parameters (malondialdehyde and protein carbonyl content) were significantly higher, antioxidant enzymes activities (SOD and GSH‐Px) were significantly lower than trreatment group. Urinary Nitrate and Nitrite (NOx) levels increased in the treatment and un‐treatment group at the first three days.ConclusionPeroxynitrites play an important role in the healing process of caustic esophagitis. MEG might be used a potential adjuvant agent in treatment of esophageal caustic burn by modulating antioxidant defense mechanism.
Interaction of Human Urotensin II and Vasodilator Agents in Human Internal Mammary Artery
Authors: HE Guo‐Wei , BAI Xiao‐Yan , LIU Xiao‐Cheng , YANG Qin 
Published: June 2021

Spasm of the internal mammary artery (IMA) may occur in coronary grafting (CABG). We studied the interaction of human urotensin II (hU‐II) and vasodilators (calcium antagonists or glyceryl trinitrate (GTN)) in human IMA segments (n=102, from 46 CABG patients) in myograph (n=6 in each group). hU‐II contracted all IMA. In KCL‐contraction, full (nifedipine:98.9±3.9%) or nearly full (diltiazem:92.7±6.0%) relaxation with 18.6‐fold‐higher potency to nifedipine vs. diltiazem (EC50 −8.01±0.20 vs. −6.74±0.22 logM, p=0.002) and in hU‐II‐contraction, nearly full relaxation (nifedipine: 90.6 ±4.6%; diltiazem: 95.1±2.1%) with 6.2‐fold‐higher potency to nifedipine vs. diltiazem (EC50 −7.25±0.25 vs. −6.46±0.18 logM, p=0.014) were observed. GTN caused nearly full relaxation (95.4±5.8%) but its pretreatment failed to alter, whereas diltiazem and nifedipine pretreatment reduced contraction to hU‐II. Thus, hU‐II is a potent vasoconstrictor in human IMA. Calcium antagonists and GTN relax the contraction caused by hU‐II with different potencies. However, calcium antagonists are more effective in preventing the contraction induced by hU‐II than GTN.Supported by China Nat'l Ministry of Sci. & Tech. 2009DFB30560 & 2010CB529502(973)åTianjin Municipal Sci. & Tech. Commission 09ZCZDSF04200 &10JCYBJC26400å Hong Kong RGC (CUHK4651/07M & CUHK4789/09M); CUHK2041561, and Providence SV Med. Foundation, Portland, OR.
Enzymatic glycocalyx treatment impairs insulin‐mediated recruitment of microvascular blood volume and decreases insulin sensitivity in rats
Authors: Eskens Bart , Cobelens Hanneke , Vink Hans , van Teeffelen Jurgen 
Published: June 2021

Agonist‐induced impairment of the blood‐exclusion properties of the glycocalyx has been shown to effectively increase microvascular blood volume (MBV) (VanTeeffelen, CVR 2010). Since the rapid insulin‐mediated increase in MBV has been suggested to contribute to insulin's metabolic actions (Vincent, Diabetes 2004), we hypothesize that loss of glycocalyx impairs the ability of insulin to increase MBV and to subsequently dispose blood glucose.In rats, loss of glycocalyx was induced by a bolus of hyaluronidase; saline served as control. During anesthesia the microcirculation of hindlimb muscle was visualized with a Side Stream Dark field camera before and during intravenous insulin infusion. The RBC column width distribution of visible microvessels was determined in time. In control, median RBC column width did not change during insulin infusion but the P75 and P90 increased rapidly (<10 min) with 0.3 ± 0.1 μm and 0.8 ± 0.4 μm respectively. In the hyaluronidase treated group insulin had no effect on median, P75 and P90 of RBC column width. To measure insulin sensitivity an intravenous insulin tolerance test was performed in conscious rats. The insulin‐mediated decline in blood glucose after 15 minutes was found to be decreased after hyaluronidase treatment from 62 ± 1 to 53 ± 2% (P<0.05).It is concluded that glycocalyx degradation is associated with an impaired ability for insulin to increase MBV and to dispose glucose.Supported by DFN 2006.00.027 and NHF 2005T037
TNFα is central to the augmented myogenic response of skeletal muscle resistance arteries in heart failure
Authors: Kroetsch Jeffrey Thomas , Meissner Anja , Momen Abdul , Husain Mansoor , Bolz Steffen‐Sebastian 
Published: June 2021

A hallmark of heart failure (HF) is elevated peripheral resistance, which primarily results from an augmented myogenic response (MR, the intrinsic property of resistance arteries (RA) to adapt diameter to changes in pressure). In cerebral arteries from HF mice, tumor necrosis factor α (TNFα) plays a central role for the enhancement of MRs (through activation of sphingosine kinase‐1). We hypothesized that TNFα is equally important for the augmentation of MRs in skeletal muscle RA and hence, increased peripheral resistance in HF. HF was induced in Male C57/BL6 mice through surgical ligation of the left anterior descending coronary artery. 6–8wks post‐ligation, cremaster muscle RA were isolated and cannulated on a pressure myograph. Elevations in transmural pressure (20–100mmHg in 20mmHg steps) induced MRs that were increased in RA from HF compared to sham‐operated mice (n=7). MRs were not enhanced in RA from HF TNFα−/− mice (n=5). However, treatment with the TNFα scavenger etanercept (1mg/kg 2x/wk for 6wks post‐ligation) did not block the HF‐induced increase in MRs.Our data suggest that: (i) the augmented MR in skeletal muscle arteries contributes to increased vascular resistance in HF, (ii) TNFα is a mandatory component of this response, and (iii) chronic scavenging of TNFα might be compensated by redundant organization of MR signaling pathways.Funding: NSERC, HSFO, and CIHR
Small and intermediate conductance Ca2+‐activated K+channels regulate spontaneous contraction of mouse portal vein myocytes
Authors: Blanchette Alexandre , Charbel Chimène , Toussaint Fanny , Greenwood Iain A , Ledoux Jonathan 
Published: June 2021

Ca2+‐activated K+ channels (KCa) are key components of vascular myocytes EC coupling through their control of smooth muscle cell membrane potential. Whilst BKCa is expressed ubiquitously in smooth muscle cells, only proliferative VSMCs express KCa3.1 channels. However, mouse portal vein (mPV) is an atypical blood vessel showing spontaneous and rhythmic contractions. Since KCa channels are involved in the regulation of excitability of other cell types like neurons, the contribution of KCa2.x and KCa3.1 channels to the control of mPV excitability was investigated. Expression of KCa2.x and KCa3.1 was detected in mPV by PCR and immunohistochemistry. In single cell patch clamp studies, the RMP of isolated mPV myocytes was hyperpolarized (≈15 mV) by exposure to NS309 (10 μM), a KCa2.x and KCa3.1 channel activator. Inhibition of KCa2.x channels with UCL1689 (3 μM) reversed the effect of NS309 whilst inhibition of KCa3.1 channels (TRAM‐34; 10 μM) had no effect. NS309 significantly decreased the amplitude and increased the frequency of spontaneous contractions of intact mPV. These effects were reversed by application of UCL1689, suggesting that the NS309‐induced changes in spontaneous mPV contractions is carried out by KCa2.x channels. This study suggest that KCa2.x and KCa3.1 channels are expressed in mouse portal vein myocytes and play an important role in regulation of spontaneous contractions.Supported by FICM
TNFα affects sphingosine‐1‐phosphate signaling through modulating the expression of the cystic fibrosis transmembrane regulator (CFTR) in vascular smooth muscle cells
Authors: Meissner Anja , Bolz Steffen‐Sebastian 
Published: June 2021

Cellular effects of the ubiquitous signaling molecule sphingosine‐1‐phosphate (S1P) are tightly controlled by a rheostat between the S1P‐generating enzyme sphingosine kinase 1 (Sphk1) and its functional antagonist S1P phosphohydrolase 1 (SPP1). The intracellular localization of SPP1 requires the import of S1P prior to its degradation. We propose that the import into vascular smooth muscle cells (VSMC) critically depends on the cystic fibrosis transmembrane regulator (CFTR) and that changes in CFTR function regulate S1P signaling. In the vasculature, S1P regulates resistance artery myogenic tone and hence, peripheral resistance. Both parameters are increased in heart failure (HF), a finding that is associated with down‐regulation of vascular CFTR. The pro‐inflammatory cytokine TNFα mechanistically links HF and CFTR because (1) TNFα down‐regulates CFTR mRNA and protein expression, (2) increased TNFα expression and down‐regulation of CFTR in resistance arteries co‐localize in HF and (3) sequestration of TNFα with etanercept normalizes CFTR expression. In addition to these genomic effects, TNFα also acutely controls CFTR function through regulation of its membrane abundance.Our data suggest that TNFα‐mediated down‐regulation of CFTR function shifts the balance between S1P synthesis and degradation, leading to enhanced bioavailability and vascular/cellular effects of S1P.Funding: HSFO, CIHR
Role of ZFM1 in smooth muscle cell phenotype regulation
Authors: Cattaruzza Marco , Nogoy Nicole , Hecker Markus 
Published: June 2021

Vascular smooth muscle cells (SMC) can rapidly develop a synthetic phenotype in response to growth factors ‐ a phenomenon with major impact on atherosclerosis. Despite its clinical relevance little is known about the mechanisms of this potentially reversible process.Using primary human cultured SMC and platelet‐derived growth factor (PDGF; 60 U/mL) we here show that the transcriptional repressor ZFM1 is a phenotype‐stabilizing factor in these cells. Exposure of SMC to PDGF leads to proliferation and synthetic gene expression. Interestingly, PDGF causes a rapid repression of ZFM1 gene transcription through replacement of Sp1 from the ZFM1 gene promoter by the transcription factor early growth response‐1. The subsequent drop in ZFM1 abundance disinhibits both proliferation and gene expression and is a prerequisite for PDGF‐induced effects in SMC. Consequently, siRNA‐induced ZFM1 knock down alone is sufficient to increase proliferation and expression of PDGF‐sensitive gene products. Conversely, over‐expression of ZFM1 effectively suppresses all effects of PDGF exposure.ZFM1 expression levels pivotally determine the SMC phenotype: Whereas its down‐regulation is necessary for PDGF‐induced changes, the maintenance of ZFM1 expression is sufficient to maintain a contractile SMC phenotype.
Potassium ATP channel function is altered in mesenteric arteries of old high salt fed rats
Authors: Whidden Melissa Ann , Basgut Bilgen , Kirichenko Nataliya , Erdos Benedek , Tumer Nihal 
Published: June 2021

Hypertension is a risk factor for cardiovascular disease and dietary salt is a contributing factor to high blood pressure. Increased salt intake in the elderly has been shown to impair relaxation of resistance vessels. Therefore, we examined whether a high salt (HS) diet alters the function of KATP channels in mesenteric arteries (MAs) from young and old rats. Young (7 mo) and old (29 mo) F‐344xBN rats were fed a control or HS diet (8% NaCl) for 12 days and 2nd order MAs were used for vascular measurements. Acetylcholine (Ach)‐induced relaxation was significantly reduced with age. Relaxation to Ach was 92 ± 2% in young vs. 81 ± 4% in old arteries. Pretreatment with the KATP channel blocker glibenclamide only reduced relaxation to Ach in young MAs. On a HS diet, dilation to Ach was reduced in old salt MAs (60 ± 3%) when compared with old control arteries (81 ± 4%; P<0.001). Glibenclamide reduced Ach‐induced dilation in young salt MAs but had no effect on old salt MAs. Cromakalim (KATP channel opener) dilation was reduced in old salt MAs when compared with old control arteries. Maximal relaxation to cromakalim was 99 ± 1% in old control vs. 85 ± 5% in old salt arteries (P<0.05). These findings demonstrate that age impairs endothelium‐dependent dilation in MAs. Furthermore, a HS diet alters the function of KATP channels in isolated MAs and affects the mediation of dilator stimuli.Supported by the Medical Research Service of the Department of Veterans Affairs and NIA T32 AG000196 award.
Regulation of TMEM16A by a novel mechanism involving PKC in biliary epithelium
Authors: Dutta Amal Kumar , Khimji Al‐Karim , Kresge Charles , Rockey Don , Feranchak Drew P. 
Published: June 2021

TMEM16A is a Ca2+‐activated Cl− channel in the apical membrane of biliary epithelial cells (BECs), and contributes to biliary secretion and bile formation [Dutta et al. JBC, 2010]. Extracellular nucleotides activate TMEM16A via binding P2 receptors and increasing [Ca2+]i. While PKC contributes to ATP‐mediated secretion in BECs, the role in TMEM16A regulation is unknown.AimTo determine if PKC contributes to Cl− transport in BECs through regulation of TMEM16A.MethodsStudies were performed in human biliary Mz‐cha‐1 cells. Cl− currents were measured by whole‐cell patch clamp.ResultsTMEM16A Cl− currents were activated by exposure to extracellular ATP or increasing Ca2+ in the patch pipette. Currents had a reversal potential of 0 mV, time‐dependent activation and outward rectification. Currents were significantly inhibited by anti‐TMEM16A siRNA. In the presence of the PKC inhibitors Chelerithrine or Gö6976 Cl− currents were significantly inhibited. Conversely, activation by PMA resulted in large Cl− currents. Intracellular dialysis with recombinant PKCα activated Cl− currents with identical biophysical properties to TMEM16A.ConclusionPKCα couples ATP‐mediated signaling to TMEM16A activation in BECs. Modulation of kinase signaling pathways may represent a target for increasing biliary secretion and bile formation.[Studies are supported by AASLD/ALF Liver Scholar Award 2010, Children's Medical Center Foundation grant (Dutta), and NIH NIDDK DK078587]