bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of gut microbiome modulation on alpha/beta diversity, persistent pain‐depressed behaviors and inflammation in female Fisher rats with or without voluntary access to running wheels
Authors: Payne Emily , Brackin Rebecca , Harrington Kylee , Richard Philomena , Couture Sarah , Rieder Courtney , Sannajust Sebastien , King Tamara , Mattei Lisa , Lee Jung‐Jin , Bittinger Kyle , May Meghan , Stevenson Glenn W.
Published: June 2021

Given the reported effects of gut microbiome modulation on local gut inflammation and intestinal pain, it is possible that gut microbiota regulate persistent or chronic pain conditions that are distal to the gut, including pain states in the extremities. This study evaluated the effects of gut microbiome modulation on formalin pain‐depressed behaviors and formalin‐induced paw inflammation in female Fisher rats. Pilot data indicate that (1) a two‐week regimen of the narrow‐spectrum gram‐positive antibiotic vancomycin (500mg/L) in drinking water depleted Firmicutes and Bacteroidetes diversity / density in rats with or without access to running wheels; (2) formalin alone (0.5, 2.5, 5%) produced concentration‐dependent biphasic licking behavior of injured hind paw across 60 min and concentration‐dependent depression of voluntary wheel running for 7 consecutive days; (3) two‐week antibiotic treatment prior to formalin administration had a protective effect manifested as attenuation of Phase II formalin scores, and complete reversal of formalin pain‐depressed wheel running for 7 consecutive days; (4) the protective effects of vancomycin on formalin pain‐related outcomes were associated with divergent changes to proteobacteria in sedentary vs. voluntary exercised rats. These data indicate that a narrow spectrum gram‐positive antibiotic can have lasting protective effects on persistent pain‐related behaviors and that associated changes to gut microbiota vary as a function of sedentary vs. exercise condition. Parallel mechanistic studies are currently assessing the efficacy of probiotic and fecal microbiota transplant procedures vs. opioid compounds to block antibiotic‐induced modulation to formalin pain‐related outcomes.

Support or Funding Information

This research supported by a NIH COBRE grant (P20GM103643) that supports an animal behavior core facility, and a COBRE Pilot award and NIAMS R15 AREA grant (AR054975) to G.W.S.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Effects of Polysaccharides from Dendrobium Officinale on Intestinal Barrier Functions of Rats Induced by Excessive Consumption of High Fat and Sucrose Diet
Authors: Yan Meiqiu , Si Qiuqiu , Su Jie , Yu Jinjin , Lei Shanshan , Li Bo , Wang Ting , Yang Zhiyuan , Chen Suhong , Lv Guiyuan
Published: June 2021

Accumulating evidence indicates that improper diet can damage host gut barrier function and increase endotoxin level in the bloodstream. Dendrobium officinale as a traditional herb medicine mainly used for diabetes showed obvious protective effect in various metabolic diseases. Meanwhile it has obvious enterogastric function, such as modulating of enteric dysbacteriosis, improving gut barrier, promoting digestion, etc. Polysaccharides have been verified are the main effective fraction. In present study, polysaccharides from Dendrobium Officinale(DOP) was given via oral administration to rats for 10 weeks to investigate its effects on intestinal barrier functions, including the mechanical barrier and biological barrier function. It was found that DOP administration could significantly down‐regulate the level of TC, GLU and HOMA‐IR, up‐regulate the expression of claudin‐1, occludin in ileum, markedly improve the levels of interleukin‐6 (IL‐6) and tumor necrosis factor ‐α(TNF‐α), and decrease the level of diamine oxidase (DAO) and lipopolysaccharides (LPS) in serum. Meanwhile, the polysaccharide decreased the Firmicutes‐to‐Bacteroidetes ratio and upregulated the production of acetate, propionate and butyrate. Our results indicated that the polysaccharides from stem of Dendrobium Officinale might ameliorate insulin resistance induced by high fat and sucrose diet by regulate the intestinal barrier functions.

Support or Funding Information

The project supported by the National Natural Science Foundation of China (81703772,81673638), National Key R&D Program of China (2017YFC170202, 2017YFC170203), Natural Science Foundation of Zhejiang Province (LQ17H280005), Opening Project of Zhejiang Provincial First‐rate Subject (Chinese Traditional Medicine), Zhejiang Chinese Medical University (Ya2017010)

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Nrf2 deficiency in aged mice exacerbates cellular senescence promoting cerebrovascular inflammation
Authors: Kiss Tamas , Fulop Gabor A , Tarantini Stefano , Balasubramanian Priya , Yabluchanskiy Andriy , Farkas Eszter , Bari Ferenc , Ungvari Zoltan , Csiszar Anna
Published: June 2021

Aging‐induced pro‐inflammatory phenotypic alterations of the cerebral vasculature critically contribute to the pathogenesis of vascular cognitive impairment. Cellular senescence is a fundamental aging process that promote inflammation, however, its role in cerebrovascular aging remains unexplored. The present study was undertaken to test the hypothesis that advanced aging promotes cellular senescence in the cerebral vasculature. We found that in cerebral arteries of 24 month old mice expression of molecular markers of senescence (p16INK4a, p21) is up‐regulated as compared to that in young controls. Induction of senescence programs in cerebral arteries is associated by an up‐regulation of a wide range of inflammatory cytokines and chemokines, which are known to contribute to the senescence‐associated secretory phenotype (SASP) in vascular cells. Age‐related cerebrovascular senescence and inflammation are associated with neuroinflammation, as shown by the molecular footprint of microglia activation in the hippocampus. Genetic depletion of the pro‐survival/anti‐aging transcriptional regulator Nrf2 exacerbated age‐related induction of senescence markers and inflammatory SASP factors and resulted in a heightened inflammatory status of the hippocampus. In conclusion, our studies provide evidence that aging and Nrf2 dysfunction promote cellular senescence in cerebral vessels, which may potentially cause or exacerbate age‐related pathology.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Is hsa‐miR‐21‐5p a potential biomarker of vulnerable atherosclerotic plaque?
Authors: Kowara Michał Krzysztof , Paskal Wiktor , Gondek Agata , Opolski Grzegorz , Cudnoch‐Jêdrzejewska Agnieszka Barbara
Published: June 2021

INTRODUCTION

Vulnerable atherosclerotic plaque localized in coronary arterial bed is clinically important, because its rupture leads to a thrombus generation, which can totally occlude the culprit coronary artery causing myocardial infarction. Therefore finding a biomarker characteristic for a vulnerable plaque is warranted. A potential candidate is hsa‐miR‐21‐5p, a microRNA particle which promotes atherosclerotic plaque destabilization by increasing MMP‐9 expression and by enhancing local inflammatory state (negative regulation of SMAD‐7 expression).

AIM OF THE STUDY

Assessment, whether hsa‐miR‐21‐5p serum level differs significantly in patients with unstable coronary artery disease comparing to patients with stable coronary disease and myocardial infarction.

MATERIALS AND METHODS

Patients (n=42) were divided into 5 groups – ST‐segment elevation myocardial infarction (STEMI) (n=8); non‐ST segment elevation myocardial infarction (NSTEMI) (n=10), unstable angina (n=8), stable coronary artery disease (sCAD) (n=8) and 8 healthy volunteers (W). Serum samples were taken and hsa‐miR‐21‐5p relative expression level (in reference to hsa‐miR‐191‐5p and hsa‐miR‐93‐3p) was measured in each sample by RT‐qPCR. Serum samples form STEMI, NSTEMI and UA groups were taken within 24 hours of admission, before coronary angiography procedure. The results were statistically assessed on STATISTICA 13 programme.

RESULTS

The results have shown, that hsa‐miR‐21‐5p serum level differs significantly between STEMI and UA group (5,955 vs 2,311; p= 0,04). No significant differences occurred between UA and CAD groups (2,311 vs 1,990; p=0,66) and between CAD and healthy volunteers (1,99 vs 1,79; p = 0,77). Comparison between other groups (STEMI vs NSTEMI, NSTEMI vs UA) showed no statistically significant differences in hsa‐miR‐21‐5p relative expression level.

CONCLUSIONS

The study has shown no evidence supporting the hypothesis, that hsa‐miR‐21‐5p is a biomarker of a vulnerable atherosclerotic plaque, because its expression level didn't vary significantly between UA and CAD group. However, a significant difference in hsa‐miR‐21‐5p serum level between STEMI and UA group was found. This correlation could indicate, that hsa‐miR‐21‐5p plays a role on initial stages of myocardial ischemia and infarction.

Support or Funding Information

None

The relative expression level of hsa‐miR‐21‐5p between different study groups (STEMI vs UA; UA vs CAD; CAD vs W).

image

The relative expression level of hsa‐miR‐21‐5p between different study groups (STEMI vs UA; UA vs CAD; CAD vs W).

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
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 Information

Supported 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 Information

Wellcome Trust, British Heart Foundation

This 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

Background

Tumor 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).

Methods

Human 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.

Results

We 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).

Conclusion

The 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 Information

National 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

Background

Circadian 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.

Methods

Circadian 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.

Results

We 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.

Conclusion

Our 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 Information

This 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 Information

18H03166 JSPS KAKENHI Grant‐in‐Aid

This 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.

Purpose

To determine if increased circulating TMAO induces arterial stiffness in young mice.

Methods

Young 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.

Results

TMAO 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).

Conclusion

TMAO 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 Information

R01 HL134887, F32 HL140875

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Altered Wave Reflection in Patients with Duchenne Muscular Dystrophy (DMD)
Authors: Witman Melissa A , Katulka Elissa K , Hirt Alexandra E , Berube Felicia R , D'Agata Michelle N , McCulloch Michael A , Scavina Mena
Published: June 2021

Cardiovascular complications are progressive in Duchenne Muscular Dystrophy (DMD) with cardiomyopathy/heart failure characterized as the leading cause of death in these young patients. Increased wave reflection augments pulsatile load on the heart and is known to be predictive of new onset heart failure in adults. Patients with DMD may have higher wave reflection as measured by augmentation index (AIx) but this has yet to be comprehensively studied in these patients. Given the incidence of dilated cardiomyopathy in DMD, a better understanding of the pulsatile load and ventricular‐arterial interactions could provide valuable insight into disease progression and management.

PURPOSE

Thus, the purpose of this study was to characterize wave reflectance and pulsatile load with wave separation and wave intensity analyses in a group of patients with DMD compared to typically‐developing controls.

METHODS

Assessments were performed on 23 boys (10 DMD and 13 typically‐developing controls (CON)) between the ages of 8 and 18 years. A brachial artery oscillometric‐cuff device was used to record brachial artery pressure waveforms that were calibrated and synthesized to central pressure waves using a generalized transfer function. Pulse wave analysis (PWA) was performed to determine central blood pressures and AIx. Wave separation analysis was also used to determine the relative contributions of forward (Pf) and backward (Pb) pressure waves and reflection magnitude (RM=Pb/Pf).

RESULTS

Patients with DMD had a significantly higher augmentation index (AI) as measured by PWA (DMD: 21.2 ± 5 vs CON: 0.9 ± 2 %, p<0.05) but no difference in central pulse pressure (DMD: 34 ± 3 vs CON: 30 ± 1 mmHg). There was also no difference in Pf between groups (DMD: 27 ± 2 vs CON: 26 ± 2 mmHg). However, both Pb (DMD: 14.0 ± 1 vs CON: 11.7 ± 1 mmHg, p<0.05) and RM (DMD: 52.0 ± 1 vs CON: 43.5 ± 2 %, p<0.05) were significantly elevated in the children with DMD.

CONCLUSION

These preliminary data suggest that patients with DMD have higher wave reflection, which may indicate increased arterial stiffness and increased pulsatile load on the heart.

Support or Funding Information

Grant support: NIH P20GM113125

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 Effects of Nicotine on Cardiac Function and Structure
Authors: Oakes Joshua , Knowling Joselyn , Lazartigues Eric , Yue Xinping , Gardner Jason
Published: June 2021

Nicotine is the addictive chemical in tobacco‐related products, such as cigarettes, water pipes, e‐cigs, and chewing tobacco. While the effects of smoke from cigarettes and cigars are well known, the rise in popularity of smokeless electronic cigarettes (e‐cigs) brings new questions about the effects of nicotine itself on the development of cardiovascular disease. These “smoke‐less” products have grown in popularity due to reduced costs, increased social acceptance, and a belief that e‐cigs are a less dangerous alternative to smoking.

Nicotine use is associated with hypertension and may activate the renin‐angiotensin system when inhaled. The renin‐angiotensin system regulates blood pressure, and a major component of the system, angiotensin‐II (Ang‐II), can cause cardiac hypertrophy and fibrosis. However, most animal studies administer nicotine via infusion, and very little is known about the effects of chronically inhaled nicotine.

Thus the goal of our study is to investigate the effects of chronic inhaled nicotine on cardiac function and structure.

C57BL/6 male mice aged 8–12 weeks were used in this study. Mice were exposed to nicotine vapor in their home cage using an exposure system that provides control of chronicity and nicotine dosing. Mice were exposed for 12 hours/day corresponding with the dark cycle. Following 4 weeks of either nicotine or air exposure, subsets of these groups were implanted with osmotic mini‐pumps containing Ang‐II to induce hypertrophy and fibrosis. Cardiac function was assessed by ultrasound echocardiography and tissue samples collected for protein and mRNA analysis. While there was no significant change in left ventricular function, we found that nicotine blunted Ang‐II mediated hypertrophy in the posterior wall (0.83 ± 0.03 mm, n=19) compared to Ang‐II exposed mice (0.93 ± 0.02 mm, n=19, p< 0.01). While there were no differences in collagen 1 and 3 mRNA expression between groups, our preliminary data showed an increase in collagen I protein expression in nicotine exposed mice compared to air controls (1.27 ± 0.05 vs. 1 ± 0.09, n=2–3 respectively).

In conclusion, while nicotine does not appear to affect left ventricular cardiac function, nicotine does blunt Ang‐II mediated hypertrophy. In addition, there is also evidence for increased cardiac collagen deposition in nicotine exposed mice. Future studies to measure right ventricular function, cardiomyocyte size, hypertrophic pathways, and cardiac fibroblast activity are in progress.

Support or Funding Information

NHLBI R01 HL135635

NIH Grant #R25GM121189

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Rats are Protected from the Stress of Chronic Pressure Overload Compared with Mice
Authors: Nishimura Koichi , Oydanich Marko , Zhang Jie , Vatner Dorothy E , Vatner Stephen F
Published: June 2021

Little is known about differences in responses to cardiac stress in different rodent species, i.e., rats vs mice. The goal of this investigation was to compare the effects of chronic, 1‐month, thoracic aortic constriction (TAC) in Sprague Dawley rats and C57BL/6 mice. Sham and TAC procedures were conducted in both rodent groups. TAC, in the thoracic aorta, just distal to the aortic valve, induced similar left ventricular (LV) aortic pressure gradients across the aortic constriction, but there was no pressure gradient in sham operated animals. LV ejection fraction was no different in sham rats and mice (73 ± 1%), and did not fall with TAC in the rats, but fell significantly, p<0.05, in mice with TAC to 59 ± 2%. LV end diastolic pressure was also not different in sham rats and mice (5 ± 1 mmHg) and did not increase with TAC in rats, but increased, p<0.05, in TAC mice to 15 ± 2 mmHg. The next goal was to examine potential mechanisms mediating these major differences in LV function. First, we examined LV systolic wall stress, which was also similar in sham rats and mice (73 ± 1 kdyn/cm2) and did not rise significantly in TAC rats, but rose, p<0.05, to 117 ± 7kdyn/cm2 in TAC mice. Since TAC induces LV hypertrophy, which in turn, impairs subendocardial coronary perfusion and coronary reserve, and consequently LV function, angiogenesis and arteriogenesis were examined next, as these mechanisms could alleviate the coronary subendocardial hypoperfusion. Immunofluorescent Ki67 staining of capillaries and arterioles revealed increased angiogenesis, i.e., greater increases, p<0.05, in capillaries in TAC rats (6.7 ± 0.3 Ki67+Isolectin positive cells/field) than in TAC mice (4.2 ± 1.1 Ki67+Isolectin positive cells/field). Arteriogenesis was also increased more in TAC rats than TAC mice, reflected by greater increases, p<0.05, in Ki67 stained arterioles in TAC rats (19.8 ± 0.3 Ki67+SMCα positive cells/field) vs TAC mice (7.9 ± 1.2 Ki67+SMCα positive cells/field). Thus, rats are more resistant to development of cardiac failure with chronic TAC compared with mice. The mechanism of this protection involved reduced LV systolic wall stress and increased angiogenesis and arteriogenesis in the rats with chronic pressure overload.

Support or Funding Information

Funding support: NIH R01 HL124282

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Administration of Losartan Improves Myocardial Functional Performance in Rats with High‐Fat Diet‐Induced Obesity
Authors: de Oliveira Silvio Assis , de Araújo Muzili Nayara , de Carvalho Marianna Rabelo , de Campos Dijon Henrique Salomé , Cezar Marcelo Diarcádia Mariano , Ota Gabriel Elias , de Morais Camila Souza , Okoshi Katashi , Okoshi Marina Politi , Cicogna Antonio Carlos , Martinez Paula Felippe
Published: June 2021

Extensive evidence has shown that high‐fat diet is associated with chronic activation of the renin‐angiotensin system (RAS) and left ventricular remodeling. This study was developed to evaluate the impact of angiotensin‐1 (AT1) receptor antagonism on myocardial function in rats with high‐fat diet‐induced obesity.

Methods

Male Wistar rats (n=48) were fed a control (2.9 kcal/g, C) or high‐fat (3.6 kcal/g, O) diet for 20 weeks. After the 16th week, the rats were assigned into four groups: C, O, CL, and OL. CL and OL groups received Losartan (30 mg/kg/day) in drinking water during four weeks. At the end of the experiment, body composition and systolic blood pressure were assessed, and echocardiogram analysis was performed. Mechanical performance of papillary muscles was evaluated under basal condition with 2.5 mM calcium ([Ca+2])o and after inotropic stimulation: post‐rest contraction (PRC) and change in extracellular [Ca+2]o from 1.0 to 2.5 mM.

Results

Both O and OL groups presented higher body weight and adiposity than their respective controls (p<0.05). Systolic blood pressure did not differ among groups. O and OL groups had greater left ventricular weight‐to‐tibia length ratio and posterior wall shortening velocity (C 42.92±4.45; O 48.72±4.81; CL 42.82±3.60; OL 47.96±4.03 mm/s). In papillary muscles evaluation, CL presented reduced negative tension derivative (‐dT/dt) in comparison to the C group at basal condition. After 60 seconds of PRC, both O and CL had lower relative variations in ‐dT/dt (C 55.9±20.9; O 47.1±13.3; CL 47.7±15.9; OL 51.1±14.5%) and peak developed tension than C. Also, OL had higher relative variation in DT than CL and O (C 65.7±23.6; O 56.3±13.9; CL 58.0±17.4; OL 66.4±17.4%), while variation of positive tension derivative (+dT/dt) was increased in OL compared to CL and O groups. After increasing [Ca2+]o to 2.0 and 2.5 mM, the relative variation in DT and +dT/dt were higher in OL than CL and O, respectively. OL showed increased ‐dT/dt in comparison to CL at extracellular calcium concentrations of 1.5, 2.0, and 2.5 mM.

Conclusion

Angiotensin II antagonism with losartan improves myocardial functional performance in rats with high‐fat diet induced‐obesity.

Support or Funding Information

Financial support: CAPES; CNPq; FUNDECT/MS.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Mice with endothelium‐selective deletion of adenosine kinase are protected against pressure overload induced left ventricle contractile dysfunction
Authors: Davila Alec , Tian Yanna , Czikora Istvan , Li Jie , Su Huabo , Huo Yuqing , Bagi Zsolt
Published: June 2021

Microvascular vasodilator dysfunction frequently accompanies myocardial contractile dysfunction, but the mechanistic interrelationship between these pathologies remains poorly understood, and hence therapeutic interventions are limited. We sought to determine if vascular endothelium selective inhibition of adenosine kinase (ADK), the major adenosine metabolizing enzyme, augments vasodilation and improves pressure‐overload induced left ventricle (LV) systolic and diastolic dysfunction. Mice with endothelium‐selective ADK deletion (ADKVECKO) and wild types (WT) underwent transverse aortic constriction (TAC) or sham surgery. We measured agonist‐induced vasodilation in isolated skeletal muscle arterioles and performed echocardiographic assessment of LV systolic and diastolic function. We found that TAC increased LV wall thickness and caused a progressive decline in ejection fraction (EF) as well as led to an increased deceleration time (DT), indicating the development of both LV systolic and diastolic dysfunction. TAC was also associated with impaired acetylcholine (ACh)‐induced vasodilation. ADKVECKO mice displayed a significantly augmented ACh‐induced vasodilation, which was not affected by inhibition of NO synthase, with N(ω)‐nitro‐L‐arginine methyl ester (L‐NAME). ADKVEC‐KO mice that underwent TAC exhibited a lesser degree in decline in EF and maintained normal DT without changes in LV wall thickness when compared to WT mice. Collectively, these observations suggest that a selective genetic deletion of vascular endothelial ADK provides beneficial effects on both vasodilator and LV systolic and diastolic function in pressure overload‐induced cardiac pump dysfunction.

Support or Funding Information

Support: American Heart Association 17GRNT33680171, NIH F31 HL142183‐01 and NIH R01AG054651

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
In Praise of Failure and Fractals in Physiology
Authors: West Bruce J
Published: June 2021

Pushing the natural variability from the central region of a probability distribution describing a process, out into the tails of the probability, has two effects: 1) the natural low‐level variability disappears from the policymakers field of vision, making everything appear calm and trouble free; 2) when a suppressed fluctuation does appear it is completely unexpected and devastating. Strategies that artificially suppress all variability to achieve short‐term stability of a complex environment, do just the opposite. Such deceptively calm environments eventually experience massive blowups, catching everyone off‐guard and undoing years of stability, often ending up in a far worse situation than their initial volatile state. An alternate strategy would be to take advantage of natural variability, by judiciously applying the innovator's mantra “fail small, fail often”. In this way local failures are induced in complex processes by natural variability, as is always the case. Failures are kept small through timely human intervention and catastrophic failure is thereby avoided.

We examine the hypothesis that the control of physiological time series results from allowing the underlying process to fail in small ways, and on a fairly regular basis. The notion of suppressing the natural variability of such time series is shown to increase the likelihood of failure being catastrophic when it does occur. Herein we use the fractional probability calculus to frame our arguments and to parameterize the control process that tempers the Lévy process through a criticality‐induced potential.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.