bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gallbladder as a novel source of stem cells of the hepatobiliary system
Authors: Manohar Rohan Raoul , Guzik Lynda , Stolz Donna Beer , LaFramboise William , Lagasse Eric 
Published: June 2021

BackgroundThe identification and characterization of stem cells within the biliary system has great importance for basic biology and potential cell‐based therapy. Currently, there is a paucity of data regarding stem cells in the gallbladder. Recent data have shown that the intra‐hepatic and extra‐hepatic biliary systems develop from separate progenitors. Therefore, in the adult hepatobiliary system extra‐hepatic stem cells would be unique compared to intra‐hepatic bile duct stem cells.AimTo isolate and characterize stem cells from the adult mouse gallbladder and determine their uniqueness relative to intra‐hepatic bile duct (IHBD) cells.MethodsGallbladder cells were expanded in vitro on feeders. Limiting Dilution Analyses and Index sorts were performed to evaluate candidate stem cells markers. A matrigel‐based assay was used to examine lineage commitment of the gallbladder cells.ConclusionsWe identify CD49f as a gallbladder stem cell marker. Gallbladder stem cells exhibit clonogenic self‐renewal and morphogenesis in vitro, expand and form structures in vivo short term. Primary gallbladder and IHBD cells exhibit different phenotypic profiles by flow cytometry. Microarray analyses on gallbladder stem cells and IHBD cells in vitro indicate different genomic expression patterns. These data underscore the uniqueness of gallbladder stem cells.This work was in part supported by the Commonwealth of Pennsylvania and by the NIH grant R01 DK085711.
Strain Differences Determine the Response to Citalopram on Hippocampal Neurogenesis, Neurotrophin Mobilization and Behavior
Authors: Brookshire Bethany R , Lucki Irwin 
Published: June 2021

The objective of this study is to examine strain differences on measures of antidepressant‐related behavior and hippocampal neurogenesis in response to chronic treatment with the selective serotonin reuptake inhibitor citalopram. MRL/MpJ mice, known for superior wound healing and resilience to stress, were compared with C57Bl/6J mice on responses to chronic infusion of the selective serotonin reuptake inhibitor citalopram (5 mg/kg/day for 21 days). The animals were then evaluated in the novelty‐induced hypophagia (NIH) test and examined for increased hippocampal cell proliferation after BrdU labeling by flow cytometry. Exposure to chronic citalopram significantly reduced the latency to approach food in a novel environment in the NIH paradigm in the MRL/MpJ mouse strain but had no effect on approach latency in C57Bl/6J mice. MRL/MpJ mice also showed increased cell proliferation and increased BDNF levels in response to citalopram treatment, while C57Bl/6J mice showed no significant change in cell proliferation or BDNF levels. Overall, MRL/MpJ mice showed a significant behavioral and neurobiological response to citalopram, in contrast to the C57Bl/6J strain. These results indicate that strain differences strongly impact responses to chronic citalopram. Future studies will determine the mechanisms of antidepressant action in these mice.This research was supported by USPHS T32 MH14654 and R01 MH72832.
Regulation of the growth factor signaling modulator, sprouty 2, by PHDs and pVHL/E3 ligase
Authors: Anderson Kimberly Michelle , Ying Chunyi , Patel Tarun B 
Published: June 2021

Sprouty (Spry) proteins modulate receptor tyrosine kinase signaling and inhibit cellular processes. While levels of Spry isoforms, especially Spry2, have been shown to influence the growth of tumors from the lung, liver, breast, and prostate, little is known about the interaction of Spry with proteins involved in the hypoxic response. Here, we demonstrate that HA‐Spry 2 levels are elevated after exposure to hypoxia (3% O2) and DMOG (200μM), conditions that are known to inhibit the activity of prolyl hydroxylases (PHDs). Spry2 interacts with PHDs 1–3 as well as von Hippel‐Lindau tumor suppressor protein (pVHL)—two key players in the activation of the hypoxic response. Overexpression of all PHDs under normoxic conditions (21%O2) resulted in decreased HA‐Spry2 levels in HeLa cells. Similar results were obtained when pVHL was overexpressed in HEK293T cells. Moreover, expression of shRNA against PHD1 and PHD3 or treatment with siRNA against pVHL resulted in increased levels of overexpressed HA‐Spry2. Knockdown of endogenous PHD1 in HEK293T cells caused a further reduction in the phosphorylation of ERK upon FGF stimulation when HA‐Spry 2 was present, confirming that Spry2/PHD interactions represent an alternate mechanism by which Spry2 function can be regulated.Supported by NIH grant GM073181
Mechanisms of nerve growth factor release from a human urothelial cell line
Authors: Ochodnicky Peter , Michel Martina B. , Michel Martin C. 
Published: June 2021

Nerve growth factor (NGF) has been recently implicated in urinary bladder dysfunction, but the cellular source and mechanisms controlling its release have not been characterized yet. We studied NGF release and underlying signal transduction pathways in a human urothelial cell line UROtsa.UROtsa expressed NGF at mRNA and protein level, as determined by Real‐time PCR and immunocytochemistry, respectively. NGF was constitutively released to the medium (11.5 ± 1.4 pg NGF/mg protein/h), as measured by ELISA. Down‐regulation of proteinkinase C by pre‐incubation with phorbol ester PMA reduced NGF release down to 71±3 % of the baseline within 24 hours. In contrast, NGF release was enhanced by stimulation with bradykinin, thrombin or brain‐derived nerve factor by 121±9, 127±9, 135±8 %, respectively. In case of bradykinin, enhanced NGF release was associated with elevated mRNA expression.These data suggest that urothelial cells are able to release NGF, potentially modifiable by several G‐protein coupled and tyrosine kinase receptor ligands. Targeting these modulatory urothelial receptors may provide a novel strategy in the treatment of urinary bladder overactivity.Supported by EU grant HEALTH‐F2‐2008‐223234.
Rosiglitazone prevents insulin deficiecy induced hypertension in rats
Authors: El‐Bassossy Hany , Fahmy Ahmed , Abo‐Warda Shaimaa 
Published: June 2021

The macrovascular complications of diabetes represent the leading cause of morbidity and mortality in affected subjects. Rosiglitazone has been widely used in treatment of insulin resistance. Here we investigated the effect of rosiglitazone on insulin deficiency induced hypertension.Insulin deficiency was induced by streptozotocin (STZ, 50 mg/kg). Rosiglitazone (10 mg/kg) was daily administered two weeks after STZ injection and for 6 weeks. Insulin deficient group were left untreated for 8 weeks after STZ injection. At the end of study, non invasive blood pressure (BP) was recorded. Rings of isolated thoracic aorta were used to measure the responses to receptor (phenylephrine, PE) and depolarization (KCl) vasoconstrictors, and the endothelial dependent (ACh) and independent (sodium nitroprusside, SNP) relaxants.Insulin deficiency was associated with elevated systolic and diastolic BP while, rosiglitazone treatment prevented this elevation in BP. Insulin deficiency increased vasocontractive response of aorta to PE and KCl, decreased vasorelaxatant response to ACh without affecting response to SNP, while rosiglitazone treatment prevented the impairment in response to KCl, ACh but not to PE. In conclusion, rosiglitazone protects from the insulin deficiency induced elevation in BP through a mechanism involving prevention of the impairment in aortic vascular reactivity.
Inter‐individual differences in coupling oxygen delivery to exercising muscle metabolic demand
Authors: Walsh Jeremy James , Moynes Jackie , Kellawan Jeremy Mikhail , Bentley Robert , Bravo Michael , Shantz Rebecca , Tschakovsky Michael E 
Published: June 2021

That oxygen delivery (O2del) is “tightly matched” to metabolic demand is widely accepted based on traditional data analysis using group means. Little consideration has been given to the investigation of inter‐individual differences in this coupling.PURPOSETo determine the degree of inter‐individual differences in O2del:metabolic demand coupling in healthy young males.METHODSEleven recreationally active (271.38 ± 6.74 METS) healthy males (24.18 ± 2.08 yrs) performed rhythmic isometric handgrip contractions at a fixed metabolic demand (1 s: 2 s contraction: relaxation duty cycle, 30 kg force) until failure. Forearm O2del was calculated as arterial oxygen content (O2 saturation via pulse oximeter; [hemoglobin] via venous blood sample) x brachial artery blood flow (BABF; Doppler and Echo ultrasound). Data are mean ±SD.RESULTSBABF in last 30 s of exercise: 478 ±150 ml/min, Coefficient of variation (CV) 31%, individual subject values 249, 589, 465, 317, 475, 412, 391, 420, 700, 739, 499 ml/min. O2del last 30 s of exercise: 98 ±30 ml/min, CV 31%, individual subject values 55, 117, 92, 69, 88, 85, 75, 88, 141, 152, 115 ml/min.CONCLUSIONS“Tightness” of O2del:metabolic demand coupling varies substantially between individuals. Investigating inter‐individual variation may provide an important new approach to advancing understanding of integrated cardiovascular response support of exercising muscle. NSERC
Inter‐individual oxygen delivery differences strongly influence estimated critical power in an all out exercise test
Authors: Kellawan Jeremy Mikhail , Bravo Michael F , Moynes Jackie S , Bentley Robert , Shantz Rebecca , Tschakovsky Michael E 
Published: June 2021

PURPOSETo determine if differences in O2 delivery (O2D) between healthy subjects predicts performance in a critical power (CP) test.METHODS10 healthy male subjects lay supine with the arm at heart level and completed 10 min of rhythmic maximal voluntary contractions (1 s contraction: 2 s relaxation duty cycle). CP was calculated as the average peak contraction force during the last 30 s of the trial where force plateaued. Forearm brachial artery blood flow (FBF) during exercise (echo and Doppler ultrasound) and O2D (FBF x arterial oxygen content ([haemoglobin] from venous blood sample and oxygen saturation from pulse oximetry)) were measured.RESULTSmeans ± SD. A wide range of O2D and CP was observed. O2D 101.5 ± 25.1 ml O2/min (range 70.92–154.1 ml O2/min) & CP 25.4 ± 6.0 kg (range 17.5–34.7 kg). O2D & FBF area under the curve (AUC, ml O2/forearm volume & ml/forearm volume) for the first 200 s of exercise were predictors of CP (r2 = 0.47, 0.48 p ≤ 0.03). However, O2D & FBF total AUC during exercise was the strongest predictors rather than steady state levels achieved (r2 = 0.63, 0.66 p ≤ 0.01).CONCLUSIONSConsiderable inter‐individual differences in oxygen delivery exist during an all out CP test. These differences account for much of the inter‐individual differences in CP, supporting the contention that vasodilatory responsiveness and capacity are important determinants of small muscle mass CP. NSERC
Integrated control of coronary blood flow in exercising swine by adenosine, nitric oxide and KATP channels
Authors: Duncker Dirk J , de Beer Vincent J , Taveerne Yannick , de Graaff Han , Merkus Daphne 
Published: June 2021

The mechanism of exercise‐induced coronary vasodilation remains incompletely understood. KATP channels in conjunction with nitric oxide (NO) and adenosine have been proposed to mediate exercise hyperemia in dogs but not in swine. Different results may have been due, in part, to different routes of administration of drugs to block these pathways. Hence, we studied the role of KATP channels together with NO and adenosine in exercise hyperemia in swine, using an identical drug dosing protocol and administration route that was previously shown to virtually abolish the exercise hyperemia in dogs. Swine exercised on a treadmill at 0–5 km/h, before and after blockade of KATP channels (glibenclamide, 50 μg/kg/min intracoronary (ic)), in the absence or presence of blockade of adenosine receptors (8‐phenyltheophylline, 8PT, 5 mg/kg iv) and NO‐synthase (nitro‐L‐arginine, NLA, 1.5 mg/kg, ic). Glibenclamide reduced myocardial O2 delivery and coronary venous O2 tension at rest and during exercise. Administration of 8PT + NLA reduced coronary venous O2 tension but did not enhance vasoconstriction to glibenclamide. Despite an increase in O2‐extraction to ~90% during combined NLA + 8PT + glibenclamide, exercise‐induced hyperemia was maintained. Thus, KATP channels, adenosine and NO do not appear to be critical for exercise coronary hyperemia, and act in a linear additive fashion, in swine.Supported by NHF Grant 2000T042
Pathways mediating Ca2+ senzitization in basilar artery of the rat: feature and mechanisms
Authors: Rutkai Ibolya , Czikora Agnes , Darago Andrea , Megyesi Zita , Edes Istvan , Papp Zoltan , Toth Attila 
Published: June 2021

We characterized the Ca2+ sensitivity of isometric force production in arteria basilaris of the rat. Contractile force (in mN) and intracellular Ca2+ concentrations ([Ca2+]i, Fura‐2 340/380 ratio) were measured simultaneously in the presence of agonists and inhibitors of PKC and Rho kinase. KCl evoked 2.5±0.2 mN contraction with 0.17±0.01 increase in [Ca2+]i (n=97). The Ca2+ sensitivity of force production was 18.5 mN/340/380 ratio. Serotonin evoked 6.7±0.5 mN contraction with similar changes 0.15±0.02 in [Ca2+]i, resulting in dose‐dependent increase in Ca2+ sensitivity of force production (from 19 to 38.7 mN/340/380, EC50=32nM) (n=19). U‐46619, a thromboxane A2 receptor (TxA2) agonist evoked 4.2±0.5 mN contraction and 0.04±0.01 increase in [Ca2+]i. The Ca2+ sensitivity of force production increased from 20 to 97.9 mN/340/380 with an EC50 of 7,9 nM (n=23). The Ca2+ sensitivity of force production was not affected by PKC but decreased upon Rho‐kinase inhibition.SummaryRho kinase mediated increase in Ca2+ sensitivity of force production significantly contributed to vascular contraction in both serotonin and TxA2 receptor stimulation. Funding: TÁMOP‐4.2.1.B‐09/1/KONV‐2010‐0007
Effect of Warm‐Up Exercise on Myocardial Perfusion Studied with Wave Intensity Analysis
Authors: Rolandi Cristina , Lockie Tim , Guilcher Antoine , Perera Divaka , Redwood Simon , Marber Michael , Siebes Maria 
Published: June 2021

BackgroundThe effect of warm‐up on myocardial perfusion in patients with coronary artery disease (CAD) is not well understood. We compared outcomes of repeat exercise periods using wave intensity (WI) analysis. Coronary WI reflects the effects of cardiac contraction and relaxation on coronary blood flow dynamics and distinguishes between left ventricular (forward, FW) and microcirculatory (backward, BW) originating contributions.MethodsDuring cardiac catheterization in 10 patients with CAD, we simultaneously recorded aortic pressure, distal coronary pressure (Pd) and flow velocity (U), while the patients performed 2 serial periods of supine bicycle exercise (Ex1, Ex2). WI was calculated as (dPd/dt)(dU/dt) and the separate BW and FW contributions were derived.ResultsPatients reached similar exercise levels in Ex1 and Ex2, but time to ischemia was longer during Ex2. At the same cardiac workload, Pd was unchanged in Ex2 indicating absence of vasoconstriction. Concomitantly, U increased by 10% (p<0.03) and microvascular resistance (Pd/U) decreased by 20% during Ex2 (p<0.01). In contrast to FW, BW wave energy was more than 30% higher in Ex2 (p<0.05). The energy of flow accelerating waves was 20% higher in Ex2, with no difference in the flow decelerating waves.ConclusionOur results suggest a warm‐up effect as evidenced by indices of improved myocardial perfusion at repeat exercise.
Function of the cAMP dependent transcription factors CREM and ATF1 in the vasculature
Authors: Seidl Matthias Dodo , Steingräber Annika Kathrin , Sur Huyen , Schmitz Wilhelm , Müller Frank Ulrich 
Published: June 2021

Transcription factors of the CREB/CREM/ATF1‐family (cAMP responsive‐element (CRE) binding protein and modulator and activating transcription factor 1) play an important role in the cAMP mediated gene control. To address the vascular role of CREM and ATF1 we studied mice with a global inactivation of CREM (CKO) or ATF1 (AKO).CKO mice showed an increase in neointima formation after ligation of the carotid artery associated with an elevated proliferation rate of VSMCs in carotid media. Atherogenic high‐fat‐diet revealed a 20% increase of plaque area in CKOxApoE‐KO vs. control mice. In primary VSMC proliferation rate was increased 1.3 fold in CKO vs. controls after platelet derived growth factor (PDGF) stimulation associated with a 3 fold increased CRE‐mediated transcriptional activity.In AKO VSMCs PDGF induced proliferation was blunted compared to controls. AKO VSMCs also revealed a 1.9‐fold higher proportion of apoptotic cells after H2O2 treatment. These results were not associated with differences in neointima‐ or plaque formation.We conclude that ATF1 is in principle involved in the regulation of vascular proliferation and apoptosis but may play an inferior role under physiological conditions. Anti‐proliferative effects suggest CREM as an important factor for the pathogenesis of vascular proliferative disorders. (Supported by the IZKF Münster).
Effects of Hypoxia on Gene Expression in the Elderly
Authors: Toby Inimary , Burian Dennis , McNeely Eileen 
Published: June 2021

Many patients with underlying pulmonary disease travel each year by air. These patients may be at higher risk for developing complications due to decreased oxygen tension within their lungs, or hypoxia. At high altitudes, the lower air pressure makes it more difficult for oxygen to enter our vascular systems. In addition, aviators who fly above 12,500 feet in an unpressurized aircraft without supplemental oxygen may be susceptible to the effects of hypoxia. It is unclear what determines an individual's response and subsequent compensation to hypoxia. We enrolled a total of 62 elderly subjects aged 50–80 from three health categories: 23 healthy, 18 cardiac‐compromised, and 21 smokers. Subjects participated in a simulated flight within a hypobaric chamber under both control and exposure conditions at an altitude of 7,000 ft. We utilized microarray analysis and quantitative PCR (qPCR) to access gene expression of the subjects in response to altitude exposure. Using microarray analysis, we discovered ~155 genes involved in the physiological response to altitude exposure. The main biological functions involved were cell‐to‐cell signaling, hematological system function, and tissue development. Of the 155 genes, we utilized qPCR to measure the levels of expression for the top 35 genes. We found that hypoxia led to alterations in gene expression of important factors in the pulmonary vasculature. Our data suggests that several biomarkers exist that might be predictive of an individual's response to hypoxia.This work was supported by the Federal Aviation Administration, Office of Aviation Safety
AN AIRWAY ANTI‐INFLAMMATORY ROLE FOR FISH OIL SUPPLMENTATION
Authors: Ade Carl J , Rosenkranz Sara K , Harms Craig A 
Published: June 2021

Environmental and dietary factors cause airway immune cells to produce mediators that increase tissue inflammation and smooth muscle constriction. A high‐fat meal is one stimulus that may increase airway inflammation in healthy individuals. Supplementation with omega‐3 fatty acids can have anti‐inflammatory properties via modification of arachidonic acid metabolism.AimTo determine if omega‐3 fatty acid supplementation via fish oil will mitigate the airway inflammatory response induced by a single high‐fat meal (HFM).MethodsNon‐asthmatic males (22±3 yrs) were supplemented with 3 mg×day‐1 fish oil (FO; n=5) or a placebo (CON; n=6) for 3 weeks. Exhaled nitric oxide (eNO; a marker of airway inflammation), impulse oscillometry, pulmonary function, and triglycerides were measured prior to and 2 hours following a HFM.ResultsFollowing a HFM, triglycerides increased in both FO and CON groups (79% and 118% respectively, P<0.05). The increase in eNO was higher in the CON group compared to the FO group (26.6 ± 19.6% vs. −2.6 ± 13% respectively, P<0.05). FVC was decreased in the CON group (5.32 ± 0.77 pre‐HFM vs. 5.12 ± 0.76 l post‐HFM, P<0.05) but was unchanged in FO group (4.88 ± 0.91 pre‐HFM vs. 4.88 ± 0.80 l post‐HFM, P>0.05).ConclusionA HFM increases airway inflammation and decrease pulmonary function. Omega‐3 fatty acid supplementation via fish oil protects against HFM associated changes in airway health.
Cigarette smoke and A‐kinase anchoring proteins (AKAPs) in human airway smooth muscle function
Authors: Schmidt Martina , Oldenburger Anouk , Poppinga Wilfred , Roscioni Sara S , Heijink Irene H , Timens Wim , Skroblin Philip , Klussmann Enno , Maarsingh Harm 
Published: June 2021

COPD is a chronic inflammatory disease mainly caused by cigarette smoke (CS) and characterized by infiltration of (activated) inflammatory cells. Airway smooth muscle (ASM) also contribute to inflammatory cytokine release, smooth muscle contraction, and airway remodeling. Notably, cAMP‐elevating β2‐agonists and phosphodiesterase inhibitors differentially diminish COPD symptoms. Compartmentalization of cAMP by AKAPs could explain distinct cAMP responses.In human ASM, CS‐induced IL‐8 release was decreased by fenoterol, the PKA activator 6‐Bnz‐cAMP, while the Epac activator 8‐pCPT‐2′‐O‐Me‐cAMP showed only slight effects. Addition of PKA‐AKAP interaction inhibitor Ht31 augmented the IL‐8 release. RII overlay, western blots and RT‐qPCR demonstrated expression of AKAP79, AKAP250 and AKAP450. CSE decreased AKAP250, whereas AKAP79 was less affected and AKAP450 even enhanced, indicating disturbation of AKAP functions by CSE. Importantly, similar changes in AKAP expression were found in lung tissues of COPD patients. Our studies provide the first relation between cigarette smoke and the coordination of cAMP signaling by AKAPs. Supported by the Dutch Asthma Foundation and a Rosalind Franklin Fellowship.
Impairment of epithelial cell endocytosis by mistargeted SP‐C I73T mutant protein
Authors: Hawkins Arie Ellen , Zhao Ming , Beers Michael F. , Mulugeta Surafel 
Published: June 2021

Interstitial lung disease in both children and adults has been linked to mutations in the lung‐ specific Surfactant Protein C (SP‐C) proprotein. Among these, the missense mutation, SP‐CI73T, accounts for more than 30% of all reported SP‐C mutations. We previously reported that in A549 and HEK293 cell lines, wild type SP‐C was directly targeted to lysosomal‐like vesicles, while SP‐CI73T was uncharacteristically routed to the plasma membrane, and subsequently sorted to the lysosomes via early endosomes. This mistargeting causes impaired cellular lipid uptake and degradation. To determine whether the diminution of lipid uptake is the product of a globally dysfunctional endocytic pathway, cellular uptake of dextran was examined in HEK293 cells stably expressing either the wild type or the mutant SP‐C isoforms. We found that internalization of dextran was significantly reduced in cells expressing SP‐CI73T compared to the wild type control. Thus, our data further establishes the functional impairment caused by the SP‐CI73T mutation, and supports our previously proposed cellular mechanism and paradigm for mistargeted proteins involved in the disruption of endosomal/lysosomal sorting machinery.Supported By NIH HL090732 (SM), NIH HL19737 (MFB)