bluuebunny/crossref_metadata_2025_split huggingface dataset:
A glycosylation‐specific interaction between the Sigma‐1 and Neuorkinin‐1 receptors (659.13)
Authors: Weaver Sara , Ruoho Arnold , Yang Jay 
Published: June 2021

The putative chaperone protein Sigma‐1 Receptor (S1R) has been implicated in chronic pain via pharmacological and gene knockout studies, however, how S1R affects pain is not known. Activation of the GPCR Neurokinin‐1 Receptor (NK1R) is implicated in pain signaling. Herein we demonstrate a novel robust interaction between S1R (FLAG‐tagged) and NK1R (HA‐tagged) using co‐immunoprecipitation (co‐IP) in transiently transfected HEK293 cells. NK1R are glycoproteins with several mobility‐shifted immunoreactive bands present on a Western blot. Co‐IP demonstrates specific interaction between S1R and only the non‐glycosylated NK1R. This specific interaction was confirmed by tunicamycin‐treatment to eliminate the glycosylation and by expression of a glycosylation‐deficient NQ‐NK1R mutant. Additionally, we assay a panel of GPCRs for S1R interaction, (including the NK2R, NK3R, MOR, DA1, and MRGR), and demonstrate that all of the interactions are restricted to the non‐glycosylated GPCR. We conclude that S1R acts as a protein chaperone by a selective interaction with the non‐glycosylated GPCR proteins possibly providing insight on how S1R may influence nociceptive transmission.Grant Funding Source: Supported by the National Institute of General Medical Sciences
Autotaxin mRNA and protein expression and regulation by salmeterol xinafoate and fluticasone propionate in lung cells (660.13)
Authors: Toews Myron , Schulte Nancy 
Published: June 2021

Autotaxin (ATX) is the lyso‐phospholipase D enzyme that catalyzes the final step in the synthesis of the lipid mediator lysophosphatidic acid (LPA). ATX, LPA, and LPA receptors in the lung are all strongly associated with the pathology of pulmonary fibrosis, and increasing evidence implicates these same mediators as contributors to asthma. Accordingly, we hypothesized that the asthma drugs salmeterol xinafoate (SX), a long‐acting beta‐2 agonist bronchodilator, and fluticasone propionate (FP), an anti‐inflammatory steroid, would reduce the expression of ATX in lung cells. Cells were treated for 72 hr in the absence or presence of the drugs, alone or in combination. ATX protein assessed by Western blotting of culture medium and ATX mRNA assessed by qPCR were not detected in primary human bronchial epithelial cells or the Beas‐2B bronchial epithelial cell line. ATX protein but not mRNA was detected for human A549 alveolar adenocarcinoma cells and mouse LA4 cells, both of which represent alveolar rather than airway epithelium. Both SX and FP decreased ATX protein expression in these alveolar cells. Stronger ATX protein and mRNA signals were observed in mesenchymal cells, both primary human airway smooth muscle (HASM) cells and the HFL‐1 human fetal lung fibroblast cell line. In these cells, the level of mRNA was decreased moderately by SX, to a greater extent by FP, and decreased yet further by SX + FP. However, ATX protein was minimally decreased or not at all, despite the clear decrease in mRNA. These data reveal interesting cell type‐specific differences in ATX mRNA and protein expression, and they show that asthma therapeutic agents can reduce the expression of ATX in at least some of these cells, which may contribute to their overall therapeutic benefit in patients with asthma.Grant Funding Source: Supported by investigator‐initiated grant 115165 from GlaxoSmithKline
Identification of allosteric modulators of the D2 dopamine receptor (662.6)
Authors: Free R , Southall Noel , Doyle Trevor , Meade Julie , Conroy Jennie , Javitch Jonathan , Ferrer Marc , Sibley David 
Published: June 2021

The D2 dopamine receptor (DAR) is central in the etiology and/or therapy of numerous neuropsychiatric disorders. Unfortunately, truly specific drugs for this receptor have been difficult to obtain, primarily due to high conservation of the orthosteric binding site. We have employed a high throughput‐screening approach using the 380,000 small molecule NIH MLPCN library to identify novel allosteric modulators of the D2 DAR. The primary screen was conducted using a cell line expressing an inducible D2 DAR coupled to a chimeric Gqi5 protein, thus linking receptor activation to Ca2+ mobilization. Hits were subjected to an extensive triage strategy to characterize DAR activity and selectivity. On the basis of these analyses, 745 agonist and 499 antagonist compounds were selected and evaluated using radioligand binding competition assays to identify the nature of their receptor interactions (orthosteric or allosteric). Compounds that are ineffective in competing for binding likely exert their functional activity via allosteric mechanisms. These experiments resulted in the identification of 47 agonists and 48 antagonists that had insignificant effects on radioligand binding when tested at concentrations up to 40 μM, despite exhibiting maximal functional effects at significantly lower concentrations. These compounds would thus appear to be allosteric agonists and negative allosteric modulators of the D2 DAR.Grant Funding Source: NIH Intramural Program
Increased systemic low grade inflammation in high altitude native rats mediated by adrenergic receptors (669.7)
Authors: AL‐Hashem Fahaid , Assiri Abdullah , Shatoor Abdullah , Elrafaey Hisham , Alessa Riyad , Alkhateeb Mahmoud 
Published: June 2021

Background: There is paucity information on the effect ofhypoxiagenerated by high altitude (HA) on the systemic inflammation and its forcing mechanism in native dwellers Objectives:To comparethe serum levels of themain inflammatorycytokines and mediators in HA native rats and to search for the possible underling mechanism(s).Methods:The study was carried out between January and April 2013. Fifty male rats were bred andreared at either HA in Abha city or low altitude (LA)in Riyadh city, Saudi Arabia. The study was carried out in two stages. In the first stage, serum levels of Inflammatory markers, cell adhesive molecules, lipids profile,catecholamine,magnesium (Mg+2)and lipid peroxidation were analysed and compared between HA and LA native rats. In the second stages, inflammatory response and lipid peroxidation levels were analysed in HA native rats after treat them with either α (Prazocin)or β (propranolol) adrenergic blockage.Results: Rats of HA native area showed significant increases in the levels of inflammatory cytokines,lipid profile as well as significant increase in norepinepherine and dopamine with a concomitant decrease in Mg+2 levels and increased lipid peroxidation. Blockage of the adrenergic receptors of HA native rats is either partially (propranolol)or completely (Prazosin) ameliorated the increase in inflammatory cytokine and oxidative stress.Conclusion: our study shows that living under HA conditions results in increased systemic inflammatory reaction an effect that is mediated through sympathetic nervous system mainly viaα adrenergic receptors and could be attributed to low Mg+2 levels.
Cholinergic signaling through the alpha 7 nicotinic receptor inhibits atherosclerosis in hypercholesterolemic mice (671.7)
Authors: Ulleryd Marcus , Johansson Maria , Lundberg Anna , Folkersen Lasse , Fogelstrand Linda , Yan Zhong‐Qun , Hansson Göran 
Published: June 2021

Objective: The aim was to examine the expression of the alpha 7 nicotinic acetylcholine receptor (α7R) in human atherosclerotic plaques and to investigate α7R effects on progression of atherosclerosis in hypercholesterolemic Ldlr‐/‐ mice.Methods: Human carotid plaques and aortic lesions of hypercholesterolemic mice were stained for α7R, using immunohistochemistry. To study the role of cholinergic signaling in atherosclerosis, male Ldlr‐/‐ mice were lethally irradiated and reconstituted with bone marrow from wildtype (WT) or α7R deficient animals.Results: α7R was detected on T cells and macrophages in human carotid plaques. Ablation of hematopoietic cell α7R in Ldlr‐/‐ mice increased aortic atherosclerosis by 38%. This was accompanied by increased aortic interferon‐γ mRNA, implying increased Th1 activity in the absence of α7R signaling.Conclusion: α7R is expressed by T cells and macrophages in human plaques. Lack of α7R in bone marrow dramatically accelerates atherosclerosis in LDLr‐/‐ mice. The present study suggests that cholinergic signaling through hematopoietic α7R inhibits atherosclerosis by modulating immune inflammation.
Activation of histone deacetylase 2: a novel strategy for reversing vascular dysfunction in atherogenesis (671.9)
Authors: Pandey Deepesh , Sikka Gautam , Bergman Yehudis , Romer Lewis , Berkowitz Dan 
Published: June 2021

Although they are targeted by therapies for cancer, the implications of epigenetic modifications of histone tails by Histone Deacetylases (HDACs) for vascular homeostasis and cardiovascular diseases including atherosclerosis, diabetes and hypertension are unclear. The use of HDAC inhibitors in the treatment of cardiovascular disease is controversial, since the global HDAC inhibitor Trichostatin (TSA) was shown to accelerate atheroma formation in LDL‐receptor knockout mice.We have demonstrated that TSA causes impairment (~40%) of endothelium‐dependent vascular relaxation in isolated vascular rings. Using class‐specific biochemical HDAC inhibitors and siRNA‐mediated gene knockdown, we have identified HDAC2 as a specific, critical regulator of homeostasis in the vascular endothelium. We have also identified Arginase 2 (Arg2) as a major transcriptional target for HDAC2 that contributes to intimal dysfunction, by showing that vascular dysfunction mediated by HDAC inhibition was abolished by either pharmacologic inhibiton or genetic knockout of Arg2. Finally, inhibition of neddylation, a post‐translational modification that enhances ubiquitin‐mediated proteosomal degradation, increased the abundance of HDAC2 and caused decreased Arg2 activity. Hence, we hypothesize that atherogenic stimuli such as OxLDL and inflammation downregulate HDAC2 expression in vascular EC through NEDD8‐mediated enhancement of the proteosomal degradation of HDAC2. This reduction in HDAC2 results in the following cascade: increased Arg2 expression in EC, decreased L‐arginine concentration, impaired NO bioavailability via eNOS substrate depletion, and increased ROS. These events culminate in EC dysfunction and atherogenesis. In conclusion, activation of HDAC2 by pharmacologic agents or small molecule activators could serve as a potent strategy in an atheroprotective therapeutic regimen.Grant Funding Source: NIH
Vasoactive effects of endothelin‐1 in the mesentery and cremaster muscle of leptin deficient mice (674.11)
Authors: Vigilance Jacqueline , Frame Mary 
Published: June 2021

Leptin has been shown to up‐regulate endothelin‐1 production. We investigated the responses to endothelin‐1 (ET) in leptin deficient diabetic mice (db/db) in comparison to C57BL/6J (C57) genetic background mice in the absence or presence of endogenous NO (LNNA), and with blockade of the ETB receptor (PD142893, BQ788). The cremaster muscle of anesthetized (50 mg/kg Nembutal or 4% isoflurane) mice (n=33) was prepared for intravital microscopy. Arteriole(A)/venule(V) pairs were chosen for study. Baseline diameters in the cremaster (A/V, 30/35 um) were ~20‐30% larger than in db/dbs; in the mesentery (60/120 um) they were similar for the 2 strains. Vasodilatory tone (adenosine, 10‐4M) was not significantly different between strains, and was lower in mesentery vs. cremaster. Vasoconstrictor tone (Phenylephrine, 10‐4M) was decreased in db/db compared to C57 in the cremaster, but not mesentery. ET1 dose dependent constriction in the C57 or db/db cremaster (logM EC50: C57 ‐11.9±29.6 A, ‐11.7±2.8 V; db/db ‐11.7±4.4 A, ‐10.0 V) was suppressed by LNNA, and enhanced with ETB antagonism to a greater extent in the A vs. V. In the mesentery, baseline constriction to ET1 was diminished to a greater extent in the db/db vs C57 and was suppressed by LNNA and enhanced with ETB antagonism. Thus, the leptin deficient mouse exhibits a tissue specific loss of ET1 mediated constriction. Yet, the potential role for ETB mediated vasodilation appears similar for C57 and db/db in both tissuesGrant Funding Source: NIH DK68401, The UWI
Transmural variation and anisotropy of microvascular flow conductivity in the rat left ventricular myocardium (675.4)
Authors: Smith Amy , Shipley Rebecca , Lee Jack , Sands Gregory , LeGrice Ian , Smith Nicolas 
Published: June 2021

Three‐dimensional (3D) ex vivo data on microvascular anatomy in the myocardium is used to determine the transmural gradient in fluid transport properties via mathematical averaging methods. The 3D capillary network is modeled as a porous medium, whose conductivity is quantified in terms of a permeability tensor. This metric is directly computed by volume‐averaging blood flow solutions in model networks with geometrical and topological properties derived from an anatomically‐detailed data set recently extracted from the rat left ventricular myocardium using confocal microscopy, high‐precision sectioning and image processing techniques.Results showed that the permeability was strongly anisotropic: the network was approximately ten times more permeable in the principal direction of capillary alignment (the ‘longitudinal’ direction) than perpendicular to this direction. Structural properties of the network varied smoothly from subepicardium to subendocardium, with a 30% transmural increase in capillary diameter translating to a 130% rise in permeability in the longitudinal direction. This supports the hypothesis that perfusion is preferentially facilitated during ventricular diastole in the subendocardial microvasculature to compensate for severely‐reduced systolic perfusion in the subendocardium.Grant Funding Source: Supported by NIH GM094503‐1, EPSRC EP/F043929/1 and EP/G007527/2, and Award KUK‐C1‐013‐0 from KAUST.
Adipose‐derived cell treatment is associated with decreased ROS production and improved coronary microvascular function in advanced age (676.11)
Authors: LeBlanc Amanda , Aird Allison , Nguyen Quang , Nevitt Christopher 
Published: June 2021

In aged rats and humans, coronary blood flow reserve (CFR) is significantly decreased and may contribute to the increased risk for CVD as people age. Adipose‐derived stromal vascular fraction (SVF) cells have shown an innate capacity for angiogenesis and regeneration in the periphery. We wanted to assess the therapeutic potential of SVF to improve poor CFR in aged rats and evaluate the effect on underlying ROS signaling mechanisms.SVF was isolated from fat pads of young (4 mos) rats through mincing, enzyme digestion, and removal of buoyant adipocytes. SVF (1x10(6) cells/cm2) was plated on Vicryl® and cultured for 14 days before implantation on epicardial surface of old rats (22 mos). After 6 weeks, microspheres were injected during baseline and dobutamine infusion to evaluate CFR (hyperemic BF/ baseline BF). Coronary arterioles were isolated, pressurized and infused with ROS‐specific fluorescent dyes to detect basal levels of O2‐ (DHE, 5 uM) and NO (DAF, 5 uM). Another set of arterioles were evaluated for NO‐dependent vasodilatory function.CFR in the apical region of the LV was increased by 78+/‐10% following treatment with a SVF epicardial patch, while the papillary region was increased by 28+/‐12% compared to untreated hearts (n=8, SVF; n=3, Control). DHE and DAF mean fluorescence (measures of H2O2 and NO production, respectively) and NO‐dependent vasodilation were significantly lower in arterioles isolated from SVF‐treated hearts compared to untreated old females.These results suggest that this adipose‐derived cell‐based therapy could improve age‐related declines in the reactivity of the coronary microvasculature through ROS‐related mechanisms.Grant Funding Source: Supported by American Heart Association BGIA 120066
Myosin phosphatase isoforms in the microvasculature during endotoxemia (678.2)
Authors: Reho John , Fisher Steven 
Published: June 2021

Sepsis is characterized by widespread inflammation and severe hypotension caused by the induction of iNOS as well as other vasodilators. We hypothesized that altered contractility of resistance artery smooth muscle could play a role in the later stages of sepsis. Sepsis was modeled via a single IP injection of lipopolysaccharides (LPS; 20mg/kg), and mouse vascular tissues were harvested 24hrs post injection. We examined the expression of the myosin phosphatase (MP) regulatory (Mypt1) and inhibitory (CPI‐17) subunits. Expression of Mypt1 Exon24/leucine zipper variants may determine sensitivity to vasodilator NO, while the level of expression of CPI‐17 may determine sensitivity to vasoconstrictor NE. Mesenteric and femoral arteries and portal veins switched from the E24+/LZ‐ isoform to the E24‐/LZ+ isoform of Mypt1 (p<0.05) with decreases in total Mypt1 and CPI‐17 transcript expression (p<0.05). Relaxation to cGMP via wire myography was enhanced in α‐toxin permeabilized mesenteric arteries from LPS injected mice compared to saline injected control. Constriction to phenylephrine activation was significantly depressed in LPS injected mice compared to control. We propose that endotoxemia triggers specific changes in MP subunit expression thereby enhancing vasodilatory mechanisms and suppressing vasoconstrictor mechanisms thereby contributing to the severe hypotension of the later stages of sepsis.Grant Funding Source: HL066171
Loss of gender‐based protection against chronic stress‐induced impairments to cerebrovascular reactivity by pre‐existence of metabolic syndrome (680.10)
Authors: Brooks Steven , Stanley Shyla , Chantler Paul , Butcher Joshua , Skaff Paulina , D'Audiffret Alexandre , Frisbee Jefferson 
Published: June 2021

Previous studies demonstrate that imposition of depressive symptoms via unpredictable chronic mild stress (UCMS) or metabolic syndrome (MetSyn) impairs vascular reactivity across organ systems, including the cerebrovasculature. Consistently, the degree of altered vascular reactivity is blunted in females compared to males, regardless of the severity of depressive symptoms (with UCMS) or of the elevated risk factors (with MetSyn). We imposed 8 weeks of UCMS on 9 week old lean (LZR) and obese (OZR) Zucker rats (both genders) and determined behavioral and vascular outcomes. UCMS caused depressive symptoms in both genders; development of MS resulted in similar, but blunted, effects. UCMS (in LZR) and MetSyn (in OZR) impaired endothelial dilator reactivity and mildly increased constrictor responses in middle cerebral arteries (MCA) of both genders, but severity of the alterations was reduced in females. When UCMS was combined with MetSyn, vascular reactivity was impaired to a comparable extent regardless of gender, and ROS/inflammatory biomarker levels were comparable as well. These results suggest that gender‐based protection against UCMS or MetSyn‐induced vasculopathy in females is lost when these risks are combined.Grant Funding Source: Supported by National Institutes of Health and American Heart Association
Leptin induces CD16 expression on human monocytes in a sex‐specific manner (680.13)
Authors: Cannon Joseph , Sloan Gloria , Cortez‐Cooper Miriam 
Published: June 2021

In addition to a centrally‐mediated influence on blood pressure, leptin stimulates monocyte migration, cytokine secretion, and other functions that contribute to hypertension and atherosclerotic plaque development. These functions are characteristics of CD16‐positive monocytes implicated in the clinical progression of atherosclerosis. This investigation sought to determine if leptin promoted the development of CD16‐positive monocytes in healthy men and women ranging in age from 20‐59 years. Circulating numbers of CD14+16++ monocytes, which preferentially migrate into nascent plaques, correlated with plasma leptin in men (R = 0.68, P = 0.01), but not women. In vitro, exogenous leptin increased percentages of CD14+16++ monocytes in cultures of male cells and reduced them in cultures of female cells (P=0.03 for leptin*sex interaction). For all subjects, circulating CD14+16++ cell counts correlated with systolic pressure (R=0.45, P=0.02) and carotid intima‐media thickness (R=0.36, P=0.04). There were no sex‐related differences in total expression of leptin receptors, measured by flow cytometry, or in relative expression of different isoforms of the receptor, measured by western blots. These results support the concept that leptin promotes the development of an atherogenic monocyte phenotype and has a stronger influence in men than in women.Grant Funding Source: Supported by NIH grant HL093663
Postoperative cognitive dysfunction: effects of previous pathology (684.7)
Authors: Hovens Iris , Schoemaker Regien , van der Zee Eddy , Nyakas Csaba , van Leeuwen Barbara 
Published: June 2021

Surgery patients may experience postoperative cognitive dysfunction (POCD), potentially depending on age and pre‐operative health status. The study objective was to research the effect of prior infection on POCD in aged rats.Cognitive function after abdominal surgery was compared between healthy aged (AH, 18 months) and aged rats that had recovered from an active mycoplasma infection (AI). Healthy young rats (YH, 3 months) and un‐operated rats served as control. Cognition was assessed 10 ‐ 14 days post‐surgery in the novel object ( NO) and location (NL) test and the Morris water maze (MWM).Cognitive performance of AH was comparable to YH. In these groups surgery only led to a decline in spatial memory. AI showed impaired spatial learning and memory and impaired cognitive flexibility compared to YH, which was further impaired following surgery. Additionally, surgery led to impaired object recognition in AI. Velocity in the MWM did not differ significantly between groups.Age in itself did not lead to cognitive impairment. In healthy young and aged rats abdominal surgery only impaired spatial, hippocampal dependent, cognition. Prior infection however caused cognitive impairment and more generalized and severe POCD in aged rats, indicating that patients with a history of infection may be more prone to develop POCD. Analysis of (neuro)inflammatory markers may provide insight in the influence of prior infection on POCD.
Altered susceptibility of the blood‐brain barrier to disruption in type 1 diabetes (685.2)
Authors: Scott Jasmine , Yang Shu , Arrick Denise , Mayhan William 
Published: June 2021

Our previous studies have shown that nitric oxide synthase‐dependent responses of cerebral arterioles are impaired in Type 1 diabetic (T1D) rats by a mechanism that appears to involve an increase in oxidative stress. Since the integrity of the blood‐brain barrier (BBB) may be influenced by nitric oxide and oxidative stress, we reasoned that the susceptibility of the BBB to disruption may be altered by T1D as well. Thus, our goal was to examine basal and agonist‐induced changes in permeability of the BBB in nondiabetic and diabetic (streptozotocin; 50 mg/kg IP) rats. On the day of the experiment (2‐3 months after streptozotocin), a craniotomy was made over the parietal cortex. We measured the permeability of the BBB to FITC‐10K dextran in nondiabetic and diabetic rats under basal conditions and during topical application of histamine (eNOS‐dependent) or glutamate (nNOS‐dependent). In addition, we examined the levels of superoxide anion in brain tissue using lucigenin chemiluminescence. Finally, we measured tight junctional protein levels in brain tissue of nondiabetic and diabetic rats. We found that basal permeability of the BBB was increased in diabetic compared to nondiabetic rats. In addition, eNOS‐ and nNOS‐dependent changes in permeability of the BBB were less in diabetic compared to nondiabetic rats. Finally, tight junctional protein and superoxide anion levels were altered by T1D. We suggest that T1D can influence the susceptibility of the BBB to disruption by altering the balance between nitric oxide and superoxide anion. We speculate that altered permeability characteristics of the BBB may contribute to cognitive impairment/impaired neurovascular coupling observed in diabetic patients.Grant Funding Source: NIH HL090657