bluuebunny/crossref_metadata_2025_split huggingface dataset:
Different Impacts of Intermittent Hypoxia and Hypercapnia on Atherosclerotic Formation
Authors: Xue Jin , Poulsen Orit , Zhou Dan , Haddad Gabriel G 
Published: June 2021

Obstructive sleep apnea (OSA) is a common disorder characterized by intermittent hypoxia and hypercapnia (IHC) during sleep and has been considered a risk for atherosclerosis. However, the particular role of intermittent hypoxia (IH), intermittent hypercapnia (IC) or their combination (IHC) in inducing or promoting atherosclerosis remains obscure. To dissect the mechanisms involved, we examined atherosclerotic formation in the Aorta, Aortic arch and Pulmonary artery (PA) in pro‐atherogenesis mouse model apolipoprotein E (ApoE) deficient mice, after IHC, IH, or IC exposure on high fat diet (HFD) as compared to room air (RA) groups either under HFD or regular chow (RC). Our data revealed that all HFD‐treated mice exhibited more atherosclerotic lesions than those fed with RC (e.g. Aorta, RA‐HFD 8.1±0.8% vs RA‐RC 1.0±0.3%, p<0.01). 10‐week IHC treatment expedited atherosclerosis in Aorta, Aortic arch and PA as compared to room air controls in the presence of HFD (Aorta, IHC‐HFD 13.8±1.0% vs RA‐HFD 8.1±0.8%, p<0.01; Aortic arch, IHC‐HFD 28.5±1.9% vs RA‐HFD 16.6±2.0%, p<0.01; PA, IHC‐HFD 28.9±2.8% vs RA‐HFD 12.2±1.5%, p<0.01). Furthermore, IHC‐induced atherosclerosis in Aorta was significantly greater than in IC or IH (Aorta, IHC‐HFD 13.8±1.0% vs either IH‐HFD 7.6±0.4%, p<0.01 or IC‐HFD 11.1±0.7%, p<0.05), indicating that the effect of IHC is the result of potential interactions between IC and IH. Interestingly, in the PA, the largest atherosclerotic formation was observed in IH‐treated mice, followed by IHC then IC (PA, IH‐HFD 40.9±2.0% vs either IHC‐HFD 28.9±2.8%, p<0.01 or IC‐HFD 20.1±2.6%, p<0.01), suggesting that (a) IH has a greater effect on the PA than on the Aorta and (b) IC may alleviate IH‐ or IHC‐induced lesion in the PA. Our findings suggest that (1) IH, IC and IHC affect the development of atherosclerosis differently and (2) distinct vasculatures (Aorta and Pulmonary artery) react to IHC, IH, IC differently in atherogenesis.Support or Funding InformationSupported by the National Institutes of Health grant 5 P01 32573 (G.G.H.)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Rapid Imaging of Signaling between the Endothelium and Smooth Muscle; Development of a Rapid Remote Refocusing Epifluorescence Microscope
Authors: Buckley Charlotte , Lawton Penny , Wilson Calum , Girkin John , McCarron John 
Published: June 2021

Rapid multiplane imaging is often required when imaging dynamic processes at high magnification in live samples. However, during rapid focus switching, image quality is compromised by the repeated, rapid agitation of the sample itself and movement of the immersion medium used for the high NA lens. Remote refocusing has been successful in minimising the degraded image quality in rapid multiplane imaging, allowing rapid acquisition of multiple focal planes without sample movement.Remote refocusing lends itself very well to imaging the endothelial and smooth muscle cell layers of an intact artery. These cell layers are intrinsically linked through a rapid communication that is critical for blood vessel function. However, understanding the interplay between the two cell types is hampered by the difficulty in imaging the two layers at a sufficiently high frame rate to capture signal transmission. The cell layers are only ~10 μm apart, therefore we designed and implemented an epifluorescence‐based remote refocusing imaging system. The system can image at over 20fps in two colours, using optical switches to provide TTL pulses to trigger appropriate laser shutter opening and image acquisition at each plane. With 60X objectives, we achieved a lateral resolution of 0.96 μm and an axial resolution of 6.40 μm. We have shown, using appropriate calibration slides, that the magnification remains constant over 100 μm depth and have verified the stability of the image acquisition. Using this method, we are able to image and analyse Ca2+ activity of the endothelial cell layer independently of the smooth muscle layer and the rapid communication between the two cell types.Support or Funding InformationWellcome Trust, British Heart FoundationThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Preliminary Data on the Effect of High Laminar Shear Stress on TNFR1 and Adaptor Proteins Expression in Endothelial Cells
Authors: Aldokhayyil Maitha , Gomez Dulce , Brown Michael 
Published: June 2021

BackgroundTumor Necrosis Factor (TNF) is an inflammatory cytokine that targets the vascular endothelial cells and initiates a cascade of events that leads to endothelial dysfunction. TNF‐induced activation of NF‐κB and MAP kinases increases the expression of adhesion molecules and chemokines that cause leukocytes recruitment and activation consequently amplifying inflammation. Evidence suggests that high laminar shear stress (HLSS) mitigates inflammation and induces atheroprotective effects. Thus, the purpose of this preliminary study was to investigate the effect of HLSS on the gene expression of TNF Receptor 1 (TNFR1) and two associated adaptor proteins, TNF receptor‐associated factor‐2 (TRAF2) and lymphocyte adaptor protein (Lnk).MethodsHuman umbilical vein endothelial cells (HUVECs) from two donors were cultured and incubated with TNF (10 ng/mL) for 4hr, exposed to HLSS (20 dynes/cm2) for 24hr, or pre‐exposed to HLSS for 24hr and then incubated with TNF (10 ng/ml). The experiment was repeated 2–3 times.ResultsWe found a significant decrease in TNFR1 expression in response to TNF incubation (p = .001, Fig. 1). TNFR1 expression was further decreased with HLSS (p = .04, Fig. 1). TNF incubation and HLSS also significantly reduced TRAF2 expression by about 50% (p <.01, Fig. 2). In response to HLSS, Lnk expression was significantly reduced (p <.001, Fig 3). However, this reduction was blunted by TNF incubation for 4hr (p = .02 Fig. 3).ConclusionThe results suggest that HLSS acts as an exercise memetic to significantly affect TNF signaling proteins. HLSS may help as a novel preventive and therapeutic approach to modulate TNF signaling and improve vascular function.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
PPARγ Target Gene Retinol Binding Protein 7 (RBP7) Protects Against Endothelial Dysfunction Induced by Mitochondrial Uncoupling
Authors: Silva Sebastiao Donato , Nair Anand R , Agbor Lary N , Sigmund Curt D 
Published: June 2021

PPARγ is a nuclear receptor transcription factor that promotes an anti‐oxidant pathway in the endothelium. We previously reported that retinol binding protein 7 (RBP7) is an endothelial‐specific PPARγ target and that it is required for the protective effects of PPARγ in the endothelium. Transgenic mice expressing a dominant‐negative mutation in PPARγ specifically in the endothelium (E‐V290M) and RBP7 knockout mice (RBP7ko) exhibited increased oxidative stress and endothelial dysfunction in response to high fat diet, a cardiovascular stressor. Here, we hypothesize that RBP7 plays a protective role against endothelial dysfunction induced by the pro‐oxidant effects of mitochondrial uncoupling. We evaluated vascular responses to acetylcholine (ACh) and sodium nitroprusside (SNP) in carotid arteries from 4 and 8 month old RBP7ko mice, infused with either saline or a sub‐pressor dose of Angiotensin II (Ang II; 120ng/kg/min) for 2 weeks. As expected, Ang II infusion did not affect systolic blood pressure after 2 weeks either in wild type (WT) (4 months old: 116.2±4.2 vs 113.9±4.1 mmHg; 8 months old: 111.3±3.8 vs 109.5±2.9 mmHg) or RBP7ko (4 months old: 112.9±1.1 vs 111.8±5.2 mmHg; 8 months old: 112.2±4.2 vs 113.9±4.1 mmHg). Endothelium‐dependent relaxation to ACh was not affected by Ang II in either 4 month‐ or 8 month‐old RBP7ko (4 month old: % relaxation ‐ saline, 89.77±1.3 vs Ang II, 93.85±2.0; 8 months old: % relaxation ‐ saline, 80.02±6.8 vs Ang II, 74.65±10.6) or WT littermates (4 months old: % relaxation ‐ saline, 98.14±0.3 vs Ang II, 94.58±1.7; 8 months old: % relaxation ‐ saline, 81.43±4.7 vs Ang II, 78.64±10.4). Next, to examine if RBP7 plays a role in mitochondrial uncoupling, the vessels were pre‐incubated with the mitochondrial uncoupler Carbonyl cyanide m‐chlorophenyl hydrazone (CCCP; 1uM for 30 minutes). After CCCP, the relaxation responses to ACh in 4 month old mice were not altered in any of the groups. Interestingly, in 8 month old mice, we observed a trend towards impaired endothelial function in the carotid artery from Ang II‐infused RBP7ko compared with genotype‐matched saline‐treated mice (% relaxation: 51.96±3.8 vs 81.82±5.3, p = 0.06) as well as Ang II‐treated WT mice (% relaxation: 51.96±3.8 vs 77.1±2.0 p=0.08). There were no changes in SNP‐mediated relaxation in any of the groups. We conclude that a subpressor dose of Ang II by itself was not able to impair vascular function in 4‐ or 8‐month old mice. However in 8‐month old mice, Ang II infusion increased the susceptibility to CCCP‐dependent endothelial impairment, and RBP7 was required to mediate vascular protection against mitochondrial uncoupling triggered by CCCP.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The targeted inhibition of neuraminidase reverses endothelial glycocalyx degradation and improves endothelial function in type 2 diabetes
Authors: Foote Christopher A , Ghiarone Thaysa , Ramirez‐Perez Francisco I , Kluser Allan RK , Grunewald Zachary I , Jurrissen Thomas J , Brown Scott M , Bender Shawn B , Manrique‐Acevedo Camila , Aroor Annayya R , Padilla Jaume , Martinez‐Lemus Luis A 
Published: June 2021

Endothelial dysfunction is a hallmark vascular abnormality of type 2 diabetes (T2D) that is characterized by blunted vasodilatory responses to physiological stimuli such as blood flow‐induced shear stress. Previously, we have reported that plasma neuraminidase levels are increased in a mouse model of diet‐induced obesity that is insulin resistant and considered pre‐diabetic. Neuraminidase is an enzyme that degrades the glycocalyx, which is a structure essential for the mechanotransduction of shear stress in the process of flow‐mediated dilation (FMD). Therefore, we hypothesized that circulating neuraminidase is implicated in the degradation of the endothelial glycocalyx and the diminished FMD that are associated with T2D, and that inhibition of circulating neuraminidase activity is an effective means to restore glycocalyx integrity and endothelial function in diabetic mice. In support of this hypothesis, we provide evidence that endothelial function, as assessed by FMD and insulin‐stimulated vasodilation, is blunted in T2D vs. non‐T2D human subjects and that this impairment concurs with elevated plasma neuraminidase activity and increased concentrations of its enzymatic byproduct, sialic acid. We further demonstrate that ex vivo exposure of mouse arteries to neuraminidase significantly reduces FMD. In cultured endothelial cells, we found that neuraminidase sheds sialic acid and Syndecan‐1, which are components of the glycocalyx and that the neuraminidase inhibitor, Zanamivir, attenuates this shedding. Moreover, in an animal model of diabetes (db/db mice), we demonstrate that Zanamivir reduces plasma neuraminidase activity and concomitantly improves femoral artery FMD and vasodilatory responses to acetylcholine and insulin. We also show that endothelial stiffness, assessed with atomic force microscopy using en face aortic samples, is significantly reduced in Zanamivir‐treated compared to placebo‐treated db/db mice. We conclude that inhibition of plasma neuraminidase activity represents a novel therapeutic approach to ameliorate endothelial dysfunction and cardiovascular risk in T2D patients by reversing glycocalyx degradation.Support or Funding InformationNational Institutes of Health grants: R01 HL137769 (JP), R01 HL088105 (LM‐L).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Carom, a novel protein induced by Homocysteine suppresses endothelial cell migration through inhibiting Vascular endothelial growth factor receptor 2 (VEGFR2) endocytosis
Authors: XIA JIXIANG , XIONG XINYU , SAREDY JASON JONATHAN , YANG XIAO‐FENG , WANG HONG 
Published: June 2021

Hyperhomocysteinemia (HHcy), a syndrome displayed by high concentration of homocysteine (Hcy) in blood has been demonstrated as a significant risk factor for cardiovascular disease (CVD). We have shown that Hcy leaded to endothelial cells (EC) injuries through inhibition of proliferation and migration. Previously we have demonstrated a Hcy specifically induced gene, Carom from cultured EC and shown its inhibition of EC migration by wound healing assay. Here, through further biochemical studies, we explore mechanistic insights behind these regulations. Carom protein belongs to Bin‐Amphiphysin‐Rvs (BAR) superfamily and specifically it is a FBAR protein since it displays Fes/CIP homology (FCH) domain on N‐terminus. Using biotin homologue to label plasma membrane proteins, we find Carom overexpression with adenovirus transduction increases Vascular endothelial growth factor receptor 2 (VEGFR2) internalization in human vein umbilical endothelial cells (HUVEC) after VEGFA stimulation. The same phenomena also exist in Hcy pretreated ECs. This process is mainly dependent on clathrin mediated endocytosis, since both Monensin and dynamin GTPase inhibitor MitMAB eliminate Carom's effects on VEGFR2 endocytosis. The VEGFR2 trafficking is tightly correlated with VEGFR2 protein levels. Carom adenovirus transduction leads to significant reduction of total cellular VEGFR2 levels. Mass spectrometric analysis of Carom interacting proteins in ECs show some partner proteins are involved in subcellular organelle trafficking and cytoskeleton organization, suggesting co‐ordinations between Carom and these partners in regulating receptor endocytosis, sorting and its function. Regulation of VEGFR2 trafficking and the ensuing signaling pathways are one of the major causes accounted for Carom's inhibitory effects on EC migration.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Inflammation induced disruption in Circadian Rhythm in Pulmonary Endothelial Cells is modulated via Reactive Oxygen Species
Authors: Chatterjee Shampa , Lee Yool , Tao Jian Qin , Sehgal Amita , Sengupta Shaon 
Published: June 2021

BackgroundCircadian rhythms refer to cell autonomous oscillations that occur with a 24‐hr periodicity which are manifest in all cells. The vascular endothelium, a network that integrates biochemical and biophysical signals via the transport of blood, nutrients, inflammatory and pathogenic stimuli, is subject to circadian regulation. While the circadian clock has been characterized in systemic blood vessels and well established to contribute to various inflammatory pathologies associated with the endothelium, the mechanisms of circadian control of endothelial inflammation specifically in pulmonary inflammation is not known. The lung is important in the context of host defense which involves participation of various cell types of the mammalian lung to limit bacterial invasion; however it is the pulmonary endothelium that is the converging site for inflammation after pathogen attack. Investigating the circadian regulation of pulmonary vascular inflammation is thus crucial in understanding if lung infection and inflammation exhibit diurnal variation. We hypothesized that the pulmonary vasculature is under circadian control and that this rhythm is disrupted by inflammatory stimuli via redox mediated processes.MethodsCircadian rhythms were monitored in pulmonary artery segments and endothelial cells isolated from mPer2luciferase transgenic mice in presence of an inflammatory stimuli (LPS). Reactive oxygen species (ROS) production in LPS treated cells was measured by fluorescence microscopy using the cell permeant dye CellROX Green.ResultsWe observed that the circadian rhythm of the pulmonary endothelium was disrupted by LPS. To identify the mechanism of this disruption, ROS production in these cells was monitored. At 3 h post LPS treatment, we observed a >3 fold increase in ROS production which further increased to 6 fold by 36 h and returned to baseline values at 72 h. ROS was inhibited by pretreating the cells with the NADPH oxidase 2 (NOX2) inhibitor DPI. Addition of DPI, prior to LPS pretreatment also restored the circadian rhythmicity of the pulmonary endothelium.ConclusionOur data indicate that pro‐inflammatory stimuli can disrupt circadian rhythms in the pulmonary endothelium via NOX2 regulated ROS signaling. We speculate that under inflammatory conditions disrupted circadian rhythms in the pulmonary vascular endothelium contributes to worsening outcomes.Support or Funding InformationThis work was supported by funding from Howard Hughes Medical Institute (HHMI) to Amita Sehgal.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The dynamics of cerebral blood flow leading up to pre‐syncope in heat stressed humans
Authors: Shibasaki Manabu , Sato Kohei , Crandall Craig , Ogoh Shigehiko 
Published: June 2021

Whole‐body heat stress reduces tolerance to lower‐body negative pressure (LBNP). Lucas et al. (Am J Physiol, 2013) previously showed that elevating cerebral perfusion early in LBNP challenge (via breathing a hypercapnic gas mixture) did not restore LBNP tolerance. However, that study only evaluated blood velocity responses from the middle cerebral artery (MCA). Given regional differences in CO2 responsiveness in the cerebral circulation, that work may not accurately reflect global cerebral perfusion responses to LBNP, as it did not account for perfusion from the anterior or posterior cerebral arteries. To address this deficit, seven healthy volunteers performed progressive LBNP to presyncope during passive heat stress, with or without breathing a hypercapnic gas mixture (5% CO2, 21% O2, balanced N2) prior to the onset of LBNP; the order of the trials were randomized and performed on separate days. Internal carotid artery (ICA) and vertebral artery (VA) blood flows were measured throughout LBNP. External canal temperature increased by ~1.4 °C during heat stress (via water‐perfused suit) and was maintained during LBNP in both trials. Heat stress decreased end‐tidal CO2 (PETCO2) by ~3mmHg. Administration of the hypercapnic gas increased PETCO2to a level greater than pre‐heat stress values (43.0±2.4 to 49.3±3.6mmHg), and PETCO2 remained at or above pre‐heat stress baseline (43.7±3.6mmHg) at the end of LBNP. LBNP tolerance, evaluated by cumulative stress index, was similar between trials. Heat stress slightly decreased both ICA and VA blood flows, and subsequent inhalation of the hypercapnic gas increased both by 125±37% and133±33%, respectively, from pre‐heat stress baseline. Of note, during LBNP, both ICA and VA blood flows in the hypercapnic trial were greater relative to the respective blood flows during the control LBNP trial (all P<0.05). However, at the termination of LBNP, due to pre‐syncopal symptoms, ICA and VA blood flows decreased to similar levels between the hypercapnic and control LBNP trials. These findings suggested that hypercapnia‐induced cerebral vasodilation is insufficient to maintain cerebral blood flow, resulting in a failure to improvement in LBNP tolerance in heat stressed humans.Support or Funding Information18H03166 JSPS KAKENHI Grant‐in‐AidThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Supplementation with the Gut Microbiome‐Derived Metabolite Trimethylamine N‐Oxide Induces Aortic Stiffening in Young Mice
Authors: Casso Abigail G. , Gioscia‐Ryan Rachel A. , Sapinsley Zachary J. , Richey James J. , Zigler Melanie C. , VanDongen Nicholas S. , Angiletta Chris J. , Griffin Laura E. , Neilson Andrew P. , Seals Douglas R. , Brunt Vienna E. 
Published: June 2021

Elevated plasma levels of the gut‐derived metabolite trimethylamine N‐oxide (TMAO) cause atherosclerosis in mice and predict cardiovascular (CV) risk in humans. Stiffening of the large elastic arteries is a major risk factor and antecedent to atherosclerosis and other CV diseases (CVD), but it is unknown if TMAO contributes to arterial stiffening.PurposeTo determine if increased circulating TMAO induces arterial stiffness in young mice.MethodsYoung C57BL/6 mice (6 mo.) were fed a defined‐choline (0.07%) diet supplemented either without (Control; n=11) or with 0.12% TMAO (n=11) for 6 months. Arterial stiffness was measured in vivo by aortic pulse wave velocity (aPWV). After sacrifice, intrinsic mechanical stiffness of the aorta was measured using wire myography. A stress‐strain curve was constructed, and the elastic moduli (EM) were calculated as the slopes of the high‐force collagen‐dominant (collagen EM) and low‐force elastin‐dominant (elastin EM) regions of the curve. Abundance of arterial structural proteins was measured in aortic lysates via Western blotting.ResultsTMAO supplementation increased plasma TMAO levels vs. Control (TMAO: 31.5±4.1 μM, Control: 2.9±0.6 μM, p= 0.01), with no effect on body weight (TMAO: 41.5±1.6 g, Control: 39.7±1.6 g, p = 0.43). aPWV was higher in the TMAO group vs. Control (483±32 vs. 392±20 cm.s−1, p= 0.04). This greater aPWV in the TMAO‐supplemented group was associated with a higher collagen EM in the TMAO‐supplemented group (TMAO: 8642±437 kPa, Control: 7056±625 kPa, p= 0.05), which was accompanied by strong trends toward higher protein abundance of type 1 collagen (TMAO: 1.62±0.33 A.U., Control: 0.99±0.08 A.U., p= 0.08) and advanced glycation end products (TMAO: 1.69±0.36 A.U., Control: 1.00±0.07 A.U., p= 0.08). There were no group differences in the elastin EM (TMAO: 642±40 kPa, Control: 620±54 kPa, p= 0.75) or elastin protein expression (TMAO: 1.09±0.04 A.U., Control: 1.00±0.04 A.U., p= 0.83).ConclusionTMAO supplementation induced a marked increase in circulating TMAO concentration and aortic stiffness in young mice. The increase in aortic stiffness appeared to be mediated by increased deposition of collagen (fibrosis) and abundance of advanced glycation end products, which form crosslinks between arterial structural proteins. These preliminary results introduce a novel mechanistic link between elevated plasma TMAO levels and CV risk, suggesting that TMAO may be a promising target to prevent arterial dysfunction and reduce consequent risk of CVD.Support or Funding InformationR01 HL134887, F32 HL140875This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.