bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cortactin regulates intestinal epithelial permeability by stabilizing tight junctions (650.6)
Authors: Citalán‐Madrid Alí , García‐Ponce Alexander , Vargas‐Robles Hilda , Betanzos Abigail , Rottner Klemens , Mennigen Rudolf , Schnoor Michael 
Published: June 2021

Chronic inflammatory diseases of the intestines such as inflammatory bowel disease (IBD) are characterized by disturbed epithelial contacts and increased intestinal permeability. The actin cytoskeleton and its regulators are critical for these features. Analyzing cortactin‐KO mice, we found that the actin‐binding molecule cortactin (CTTN) controls vascular permeability. However, it is unknown if CTTN also regulates intestinal epithelial permeability. Thus, we generated a stable CTTN‐depleted Caco‐2 cell line that showed reduced transepithelial resistence (TER) and increased paracellular flux of 4 kDa FITC‐dextran. In these cells, we also observed a less developed cortical actin ring and internalization of occludin and ZO‐1. However, CTTN depletion did not cause increased apoptosis. CTTN‐KO mice also showed increased basal permeability in the colon. In healthy human colon tissue biopsies, we found that CTTN colocalized with actin and the tight junction protein ZO‐1. By contrast, in IBD patients, we observed strong internalization of CTTN resulting in a loss of colocalization with actin and ZO‐1. Our data imply that CTTN regulates intestinal permeability by controlling actin dynamics at cell contacts to stabilize epithelial junctions.Grant Funding Source: CONACYT 179895
Safety of emu oil for intestinal applications (653.9)
Authors: Mashtoub Suzanne , Cheah Ker , Howarth Gordon 
Published: June 2021

BACKGROUND. Previously, we have reported that Emu Oil (EO) lengthens intestinal crypts, a feature of intestinal growth, in experimental colitis (2012) and mucositis (2013). However, it remains unclear whether the crypt lengthening represents normal or aberrant intestinal growth. AIM. We aimed to determine if crypt depth measurements in EO‐treated rats returned to normal levels following withdrawal of EO therapy. METHODS. Dark Agouti rats (n=8/group) were gavaged daily for 10 days with Water, Olive Oil (OO) or EO (1ml) or 0.5ml EO (0.5EO). Rats were euthanized on day 10 or day 17. Intestinal weights, lengths, villus height (VH) and crypt depth (CD) were quantified. p<0.05 was considered significant. RESULTS. On day 10, jejuno‐ileum (JI) weight was increased by OO (26%) and EO (0.5ml: 15%; 1ml: 29%; p<0.01), which was normalised by day 17. On days 10 and 17, JI length was greater in OO‐ (12%) and EO‐treated rats (0.5ml: 8%; 1ml: 12%; p<0.05), relative to water controls. On day 10, OO and EO increased ileal VH (OO: 32%; 0.5EO: 22%; EO: 35%; p<0.01) and CD (OO: 17%; 0.5EO: 13%; EO: 22%); importantly however, after withdrawal of all oils, VH and CD returned to normal levels. Moreover, the VH:CD ratio (a feature of dysplasia) was unaffected in all oil‐treated rats compared to normal controls. CONCLUSIONS. The restoration of normal intestinal growth following cessation of Emu Oil therapy supports its safety for intestinal conditions.Grant Funding Source: Supported by The Rural Industries Research and Development Corporation Australia
The study of anti‐aging of Zishen Yigan Wan in vivo and vitro (657.2)
Authors: Liu Ying , Liu Ming , Wang Xuanbin , Li Hongliang , Zhang Qiufang , Zhang Xiaoyan , Wang Linhai 
Published: June 2021

The aging‐associate diseases result in greater and greater burden for the families and community in China. A traditional folk formulation, Zishen Yigan Wan comprises 11 traditional Chinese medicinal herbs. This study aimed to observe the effects of Zishen Yigan Wan on anti‐aging and the underlying mechanisms in vivo and in vitro. Compared with the model group of ICR mice, the escape latency of each group treated by Zishen Yigan Wan with low, medium and high dosage decreased significantly (P<0.01), and the number of passing though the original platform increased significantly (P<0.01); the thymus, spleen index, GSH‐PX activity of liver, SOD activity of plasma, liver and brain tissue increased significantly, respectively (P<0.01); while the MDA level of the liver and brain, the level of NO in plasma dropped significantly (P<0.01); The viability of PC12 cells pretreated with Zishen Yigan Wan at low, medium and high dosage were increased significantly (P<0.01). The studies showed that Zishen Yigan Wan could delay ICR mice aging induced by D‐galactose, and improve the ability of learning and memory and immune function of aging mice. The mechanism may be that Zishen Yigan Wan could clear away free radicals and improve the antioxidant system’s activity of the body to slow down the oxidative stress damage of the body induced by D‐galactose.Grant Funding Source: Supported by 2011 Project of Hubei Province, NO. 4
Role of reactive oxygen species as signal transducers in β2 adrenergic receptor mediated β‐arrestin signaling (662.2)
Authors: Singh Monalisa , Burns Rebecca , Moniri Nader 
Published: June 2021

Reactive oxygen species (ROS) have previously been linked to deleterious effects caused by oxidative stress as well as to inflammatory disorders, degenerative disorders and cancers. More recently, ROS have been recognized as important signaling molecules, and have been shown to be involved in G protein‐coupled receptor (GPCR) signal transduction. Our laboratory has previously shown that agonism of the prototypical GPCR, the β2 adrenergic receptor (β2AR), generates intracellular ROS and that β2AR‐associated G protein signaling is dependent on ROS. Here, we demonstrate that ROS are critical mediators of β2AR signaling to β‐arrestins. Using coimmunoprecipitation and BRET, we reveal that the physical interaction of β2AR and β‐arrestins are dependent on ROS. Furthermore, using phosphorylation of ERK1/2 as an endpoint for both G‐protein and β‐arrestin signaling, we demonstrate that ROS are required for both G protein and β‐arrestin dependent ERK1/2 phosphorylation. These results are presented in light of data, which demonstrate that β2AR agonism can lead to receptor S‐Sulfenation, a process that is dependent on ROS, and which suggests that ROS may serve a purposeful role in stabilizing β2AR in signal‐capable conformations.Grant Funding Source: Internal funding
Discovery and characterization of a G protein‐biased agonist of the D2 dopamine receptor (662.7)
Authors: Chun Lani , Free R. , Moritz Amy , Conroy Jennie , Meade Julie , Xiao Jingbo , Dulcey Andrés , Vekariya Rakesh , Ferrer Marc , Javitch Jonathan , Beuming Thijs , Shi Lei , Southall Noel , Marugan Juan , Aubé Jeff , Frankowski Kevin , Sibley David 
Published: June 2021

The D2 dopamine receptor (D2R) can activate a spectrum of signaling cascades primarily through G proteins and β‐arrestin recruitment, making it an attractive target for the development of signaling biased ligands. Unlike dopamine, which simultaneously activates G proteins and recruits β‐arrestin, a biased ligand affects only one pathway, and the development of such ligands can allow for more fine‐tuned study of receptor signaling. Our lab has identified a compound (MLS1547) that is a highly efficacious agonist at D2R‐mediated G protein‐linked signaling, but it does not recruit β‐arrestin. Rather, this compound is an antagonist of D2R‐stimulated β‐arrestin‐mediated signaling. A number of structural analogs of MLS1547 were characterized for their signaling properties, which ranged from fully biased, partially biased, to unbiased. These results provided the basis to use pharmacophore modeling and molecular docking analyses to build a preliminary structure‐activity relationship of the functionally‐selective properties of these compounds. This, along with medicinal chemistry approaches, will allow for the identification of more potent G protein‐biased analogs of MLS1547 that will enable a highly targeted approach for investigating D2R signaling in vivo, and may eventually allow for selective treatment of disease symptoms associated with D2R dysfunction.Grant Funding Source: Supported by the NIH IRP.
Endothelial cell phenotype varies by sex and tissue of origin (664.3)
Authors: Bingaman Susan , Stockard Kevin , Huxley Virginia 
Published: June 2021

Endothelial cell (EC) dysfunction is a hallmark of several vascular diseases (CVD) that also show female (F) vs. male (M) differences in incidence and severity. As these differences change with age, i.e., pre‐menopausal F < M, post‐menopausal F 蠅 M, it has been assumed that the reproductive sex hormones, particularly E2, account for the dichotomy. In spite of the correlations between hormonal changes and CVD incidence, data exist demonstrating sex‐hormone independent variations. Before the mechanisms regulating health and disease can be determined, the phenotypes of the F and M EC require description and comparison in the absence of changes in reproductive hormones. To this end we isolated EC from aorta (AEC), skeletal muscle (SkmEC) and mesenteric microvasculature (MesMEC) of young adult F and M Sprague Dawley rats. The EC evaluated under basal conditions for a variety of attributes, including morphology (size, shape, topology, EC‐specific characteristics), growth, metabolism, and receptor and signaling protein expression displayed multiple sex‐ and tissue‐specific differences. This knowledge facilitates the development of appropriate models for future investigations, both in vitro and in vivo.Grant Funding Source: Supported by DK095501, HCO6RR017353 & the MU Pulmonary/MPP Partnership
Adenosine prevents TNFα‐induced decrease in endothelial mitochondrial mass via activation of eNOS‐PGC‐1α regulatory axis (664.5)
Authors: Kalogeris Theodore , Baines Christopher , Korthuis Ronald 
Published: June 2021

To gain insight into the potential role of endothelial mitochondrial function and biogenesis in the preconditioning effects of adenosine (Ado), we incubated human microvascular endothelial cells (HMEC‐1) with TNFα in the presence or absence of Ado. TNFα produced time and dose‐dependent decreases in mitochondrial membrane potential, cellular ATP levels, and mitochondrial mass, which preceded an increase in apoptosis. These effects were prevented by co‐incubation with Ado, an NO donor (detaNO), a guanylate cyclase (GC) activator (YC‐1), or a cell‐permeant cGMP analog (8‐Br‐cGMP). The effects of Ado were blocked by a NO synthase inhibitor (L‐NIO), a soluble guanylate cyclase inhibitor (ODQ), a morpholino antisense oligonucleotide to eNOS, or siRNA knockdown of PGC‐1α. DetaNO reversed the the effect of eNOS knockdown, as did YC‐1 and 8‐Br‐cGMP, while the effect of detaNO was blocked by ODQ. Both detaNO’s and 8‐Br‐cGMP’s effects were prevented by siRNA to PGC‐1α. TNFα also decreased expression of eNOS and PGC‐1α, which was reversed by Ado. DetaNO, but not Ado, rescued expression of PGC‐1α in cells in which eNOS expression was knocked down by eNOS antisense treatment. These results support the existence of an adenosine‐triggered, mito‐and cytoprotective mechanism dependent upon an eNOS‐PGC‐1α regulatory pathway, which acts to preserve endothelial mitochondrial function and mass in the face of inflammatory challenge.Grant Funding Source: Supported by NIH grants: AA014945 & HL095486
Modulating Ca2+ entry into endothelial tubes by controlling membrane potential during muscarinic receptor activation (664.7)
Authors: Behringer Erik , Segal Steven 
Published: June 2021

Coupling of intracellular Ca2+ [Ca2+]i to hyperpolarization of endothelial cells underlies smooth muscle cell relaxation in resistance vessels. Whether membrane potential (Vm) influences [Ca2+]i levels in the endothelium remains controversial. To resolve the impact of Vm on Ca2+ influx, Fura‐2 photometry was evaluated during intracellular current injection (‐5 to +5 nA; 20 s pulses) to control Vm of endothelial tubes (width, 60 µm; length, 蠄 1 mm) freshly isolated from superior epigastric arteries of adult (4‐6 mo) male C57BL/6 mice (n蠅4). Relative to resting Vm (‐40±2 mV), current injection hyperpolarized (Vm in mV; ‐1 nA: ‐52±2, ‐3 nA: ‐64±2, ‐5 nA: ‐79±2) and depolarized (+1 nA: ‐33±1, +3 nA: ‐13±2, +5 nA: 8±3) cells. Under resting conditions, changing Vm did not affect [Ca2+]i (e.g., F340/F380 = 0.68±0.03 at rest and ‐5 nA). However, during exposure to acetylcholine (ACh; 100 nM, ~EC50), the plateau phase of the [Ca2+]i response was either enhanced [∆F340/F380 & ∆Vm (mV); ‐1 nA: 0.07±0.02 & ‐10±1; ‐3 nA: 0.16±0.02 & ‐23±2; ‐5 nA: 0.21±0.02 & ‐38±1] or reduced (+1 nA: ‐0.08±0.02 & 11±2; +3 nA: ‐0.18±0.03 & 28±3; +5 nA: ‐0.34±0.03 & 49±4) according to voltage amplitude and polarity (P<0.05). These effects of ACh and ∆Vm were abolished in the absence of extracellular Ca2+ (2 mM). Thus Vm can modulate Ca2+ entry during submaximal activation of ion channels that enable Ca2+ influx in accord with the electrochemical driving force.Grant Funding Source: Supported by R37‐HL041026 & 5T32‐AR048523
Interaction between endotoxin and histones in thrombosis (671.5)
Authors: Lam Fong , Parikh Kathan , Cruz Miguel , Rumbaut Rolando 
Published: June 2021

Histones, the protein component of nucleosomes, are released from neutrophils during inflammation and have a pro‐aggregatory effect on platelets. Recent reports suggest that histones interact with toll‐like receptor‐4; therefore, we studied the effect of endotoxin (LPS) on nucleosome formation and histone‐induced platelet aggregation. We measured plasma nucleosome levels in mice exposed to either LPS or control, and the effects of exogenous histones of photochemical‐induced thombus formation in cremaster venules. Finally, we compared the effects of LPS and histones on platelet aggregation. We observed that 4 hours after LPS, mice had a 4‐fold higher level of plasma nucleosomes compared to saline‐exposed mice (p<0.01). Furthermore, exogenous histones resulted in a decreased platelet counts (from 1.1 x 106 to 0.86 x 106/µL; p< 0.05), increased thrombin‐anti‐thrombin complexes (from 0.99 to 6.1 ng/mL; p<0.01), and accelerated rates of thrombosis (time to thrombotic occlusion was reduced from 6.5 to 4.4 min; p<0.05). Finally, whereas LPS alone did not induce platelet aggregation, it enhanced the aggregatory response after histone administration in a dose‐dependent manner (22, 28, and 38% aggregation with LPS 0, 10, and 100 ng/mL, respectively; p<0.01). Taken together, these data suggest a synergistic interaction between endotoxin and histones in producing a prothrombotic state.Grant Funding Source: Supported by a BLR&D Merit Review Award from the Department of Veterans Affairs
Niacin‐induced enhancement of lysosomal cholesterol efflux in macrophages through CD38 ‐ NAADP signaling pathway: implication in reduced foam cell formation (671.6)
Authors: Zhang Fan , Zhang Qiufang , Li Ningjun , Li Pin‐Lan 
Published: June 2021

Niacin (Nicotinic acid), a hyperlipidemia‐lowering agent, acts as a substrate in the enzymatic synthesis of lysosomal Ca2+ messenger, NAADP by CD38. Our recent studies have demonstrated that the deficiency of CD38 led to lysosomal lipid accumulation in macrophages, foam cell formation and atherosclerosis, as observed in CD38‐/‐ mice. The present study was designed to examine the effects of niacin on the foam cell formation and explore the underlying mechanisms. Using fluorescent microplate reader and confocal microscope, we found that niacin dose‐dependently (in mM: 0, 0.05, 0.1, 0.3, 1 and 2) decreased lysosomal lipid accumulation in bone marrow‐derived wild type macrophages treated with oxLDL (40 µg/ml) as stained by lysosomal lipid specific dye of Bodipy 493/503, but it had no effects in CD38‐/‐ macrophages. This niacin‐induced lysosomal lipid lowering effects were almost completely abolished by NAADP antagonist of PPADS (100 µM). In the niacin‐treated macrophages, the cholesterol level in the purified lysosomal fractions was markedly decreased. Correspondingly, oil red o staining and electron microscope assay showed that the foam cell formation was significantly reduced. These results for the first time reveal that niacin promotes lysosomal cholesterol efflux and thereby attenuates macrophage foam cell formation, which is associated with activation of CD38‐NAADP signaling pathway.Grant Funding Source: NIH R01HL115068 and R01HL091464
Changing shear stress‐induced ATP release from erythrocytes increases endothelial calcium and vascular permeability independent from nitric oxide production in intact rat venules (672.2)
Authors: Xu Sulei , He Pingnian 
Published: June 2021

Disturbed shear stress (SS) promotes atherosclerosis, thrombosis, and inflammation of the vessel wall. Endothelial cell (EC) barrier dysfunction has been implicated to play important roles in the pathogenesis of many cardiovascular diseases. However, how the disturbed blood flow affects EC barrier function in vivo and the involved cellular mechanisms remain to be identified. Our study investigated changing SS‐induced endothelial signaling and permeability in intact rat venules. EC [Ca2+]i and NO were measured in Fura‐2 AM and DAF‐2 DA loaded venules. EC eNOS activation was evaluated by immunofluorescence staining with confocal imaging. ATP released from red blood cells (RBCs) in response to SS is measured by bioluminescent assay. In response to a sudden change of SS, transient shear magnitude‐dependent increases in EC [Ca2+]i occurred only in vessels perfused with whole blood or perfusate containing RBCs, which was correlated with EC gap formation illustrated by fluorescent microsphere accumulation. Carbenoxolone, a Pannexin 1 inhibitor, significantly reduced shear magnitude‐dependent ATP release from RBCs and also abolished SS‐induced increases in EC [Ca2+]i. However, both plasma and whole blood perfusion induced shear magnitude‐dependent NO production and eNOS‐ser1177 phosphorylation. These results indicated that in intact venules ATP released from RBCs in response to the sudden change of SS is accountable for the increases in EC [Ca2+]i and vascular permeability, while SS‐induced NO production can be independent of increased EC [Ca2+]i.Grant Funding Source: Supported by HL56237, HL084338 and AHA 12PRE11470010
Evidence for a Rac1 independent mechanism for sphingosine‐1‐phosphate mediated endothelial barrier enhancement (672.7)
Authors: Zhang Xun , Adderley Shaquria , Breslin Jerome 
Published: June 2021

S1P is a bioactive lipid that tightens intercellular junctions between endothelial cells (EC) through coordinated spreading of local lamellipodia. We tested the hypothesis that S1P causes protrusions through activation of the small GTPase Rac1. Cultured human umbilical vein EC or human dermal microvascular EC monolayers were used to model the endothelial barrier. Trans‐endothelial electrical resistance (TER) served as an index of barrier function and time‐lapse imaging of EC was employed to study local lamellipodia. Rac1 expression/activity was modulated by transfection of siRNA or plasmids encoding wild‐type (WT) or dominant‐negative (DN) GFP‐Rac1, and confirmed by Western blot or fluorescence microscopy, respectively. Non‐targeting RNA sequences and GFP transfection served as respective controls. The results show that S1P (2 μM) caused rapid, coordinated protrusions of local lamellipodia from individual cells that coincided with increased TER. Neither Rac1 knockdown, nor overexpression with WT or DN Rac1 significantly changed TER, compared to controls, at 72h. Additionally, S1P significantly increased TER in Rac1 knockdown and overexpression groups, at an equivalent magnitude as controls. These data suggest that a Rac1 independent mechanism controls S1P‐induced EC protrusions and endothelial barrier enhancement. Supported by NIH R01HL098215.Grant Funding Source: Supported by NIH R01HL098215
Integration of microvascular reactivity, structure and hemodynamics for skeletal muscle function in metabolic syndrome (674.8)
Authors: Butcher Joshua , Chantler Paul , Wu Fan , Brooks Steven , Stanley Shyla , Frisbee Jefferson 
Published: June 2021

With metabolic syndrome (MS) in obese Zucker rats (OZR), the ability of in situ skeletal muscle to resist fatigue is compromised well before muscle function; implicating microvascular or perfusion‐based impairments as playing a causal role. However, our results suggest that bulk flow to muscle is not sufficiently constrained to explain the poor performance, and indices such as dilator/constrictor reactivity, vessel wall mechanics and capillary density are not strong predictors of functional outcomes. We have determined that altered RBC distribution at arteriolar bifurcations (γ) is increasingly heterogeneous in OZR muscle, iterating to produce a wide heterogeneity of pre‐capillary flow distribution vs. controls. This increased spatial heterogeneity of perfusion at bifurcations is not compensated for via temporal switching, rather it is exacerbated owing to blunted temporal activity. The combined effect of these behaviors is that microvascular hematocrit becomes increasingly heterogeneous and fixed, compromising perfusion:demand matching and muscle performance. The magnitude of the deviation of γ from 0.5, and its temporal stability are the strongest predictors of muscle performance to date.Grant Funding Source: Supported by National Institutes of Health and American Heart Association
Altered skin vasomotion in hypertensive humans (677.1)
Authors: Bruning Rebecca , Kenney W. , Alexander Lacy 
Published: June 2021

Endothelium‐dependent cutaneous vasodilation (VD) is attenuated in essential hypertensive (HTN) humans. Using spectral analysis (fast Fourier transformation) we aimed to characterize vasomotion in laser Doppler flowmetry (LDF) recordings during local heating (LH)‐induced VD before and after inhibition of nitric oxide (NO)‐dependent signaling (NOS‐I: L‐NAME) in HTN and normotensive (NTN) humans. We hypothesized that HTN would have lower total power spectral densities (PSD), and in the frequency intervals (FI) associated with endothelial and neurogenic vascular control. LDF recordings during LH experiments from 18 HTN (MAP: 108±2mmHg) and 18 NTN (MAP: 88±2mmHg) men and women were analyzed. LH‐induced VD increased total PSD for all FI (all p<0.001). HTN had a lower total PSD (HTN:30±6AU2, NTN:14±3AU2, p=0.03) and neurogenic FI (HTN:6±1AU2, NTN:17±3AU2, p<0.01) versus NTN. As a percentage of total PSD, HTN had reduced neurogenic (HTN:41±3%, NTN:51±1%, p<0.001) and higher myogenic contributions (HTN:29±3%, NTN:24±1%, p=0.04) to the total spectrum. NOS‐I decreased total PSD (p<0.001) for both groups, but HTN exhibited lower endothelial (p<0.01), neurogenic (p<0.05), and total PSD (p<0.001) compared to NTN. These data suggest that HTN results in altered neurogenic and NO‐dependent control of skin vasomotion and support the use of spectral analysis as a non‐invasive technique to study vasoreactivity.Grant Funding Source: Supported by R01‐HL093238‐02