bluuebunny/crossref_metadata_2025_split huggingface dataset:
Orexin Function in DOCA‐Salt Rat Model
Authors: Bigalke Jeremy A , Chen Qing‐Hui , Shan Zhiying 
Published: June 2021

Orexin is a neuropeptide with a large range of roles, including sleep/wake regulation, hunger, and more recently blood pressure (BP) regulation. Although the role of orexin in the paraventricular nucleus (PVN) has been investigated in several animal models such as spontaneously hypertensive rats, it remains unclear whether or not it is active in the Deoxycorticosterone‐acetate (DOCA) salt rat model, a model of salt sensitive hypertension. In this study, we investigated the role of PVN orexin signaling on metabolism and fluid homeostasis in the DOCA‐salt rat. Seven to eight week old male Sprague Dawley (SD) rats were split into three groups including DOCA‐salt (n=7), high salt (HS, n=2), or untreated control (n=6) groups. For 3 weeks, the DOCA group was treated with a subcutaneous implantation of a 75mg DOCA pellet, and fed a 1% NaCl/ 0.2% KCl water solution, the HS group was given 1% NaCl drinking water without any implantation, and the control group was left untreated. Following 3 weeks, the HS alone and DOCA‐high salt were put into metabolic cages to measure food and water intake, as well as fecal and urine output for 72 hours. Results show a significant increase in saline intake in the DOCA‐salt group when compared to the HS alone (HS: 46.41±0.52, vs DOCA‐salt: 176.69±29.24 ml, P<0.05), as well as an increased urine output (HS: 25.63±4.46, vs DOCA‐salt: 126.06±5.35 ml, P<0.001), while food intake was not significantly different. Following metabolic cages, all rats were sacrificed and subjected to either real‐time PCR or immunostaining, as well as heart weight measurements. The heart weight to body weight ratio was also measured to be larger in the DOCA‐salt group when compared to the control group (Control: 0.34±0.005%, vs DOCA‐salt: 0.43±0.025%, P<0.005), although there were no significant differences in the HS alone group compared to the others. PCR data showed the mRNA levels of orexin‐1‐receptor (OX1R) was increased by 23%, while vasopressin showed a 2.9 fold increase in the PVN of DOCA‐salt rats compared to controls. Immunostaining data also showed an increase in OX1R as well as vasopressin expression within the PVN. The combination of these results indicate a potential role for PVN orexin system hyperactivity in DOCA‐salt rat pathology, as well as vasopressin expression, salt appetite, and fluid homeostasis.Support or Funding InformationSonger Award (Bigalke)NIH R15HL129213 (Shan)Michigan Technological University and Portage Health Foundation REF (Shan)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Resolving Thrombo‐inflammation following ischemia reperfusion injury
Authors: Gavins Felicity N. E. , Becker Felix , Senchenkova Elena , Ansari Junaid , Vital Shantel 
Published: June 2021

BackgroundThe intertwined processes of thrombosis and inflammation resulting in inadequate resolution are major pathophysiological contributors of ischemia reperfusion injury (I/RI). Accumulating data supports the hypothesis that anti‐inflammatory therapies may limit thrombosis and that anti‐thrombotic therapies may reduce vascular inflammation. One such target is the anti‐inflammatory and pro‐resolving endogenous mediator Annexin A1 (AnxA1). Whilst much work has focused on the effect of AnxA1 on leukocyte accumulation during I/RI, less is known regarding its effect on platelets. Here we tested for the first time the therapeutic potential AnxA1 in resolving thrombo‐inflammation after I/RI.Material and MethodsWe used a well‐characterized model of transient middle cerebral artery occlusion with reperfusion (MCAo/R), coupled with pharmacological and genetic approaches. Fluorescence intravital microscopy (IVM) was used to monitor thrombo‐inflammatory responses, along with flow cytometry and ELISAs. (All animal experiments were approved by LSUHSC‐S Animal Care and Use Committee and were conducted in accordance with the American Association for Accreditation of Laboratory Animal Care guidelines and complied with ARRIVE [Animal Research: Reporting In Vivo Experiments]).ResultsIVM revealed heightened platelet adherence and aggregate formation within cerebral microvessels post I/RI. Using AnxA1 knock‐out mice, we found heightened cellular (neutrophil and platelet) activation as well as neutrophil‐platelet aggregate formation within the cerebral microcirculation. Administration of AnxA1 reduced platelet adherence to the inflamed cerebral endothelium following I/RI, along with a reduction in thrombus formation, thereby facilitating the resolution of thrombo‐inflammation post cerebral I/RI.ConclusionHerein we found a previously unknown phenomenon that the endogenous anti‐inflammatory and pro‐resolving mediator AnxA1 is able to exert protection through the alteration of platelet responses by orchestrating the delicate platelet phenotype in I/RI from pro‐pathogenic to regulatory. Thus, AnxA1 is a possible therapeutic strategy for effecting the resolution of cerebral thrombo‐inflammation and may therefore provide a novel anti‐thrombo‐inflammatory therapeutic target following ischemic insults.Support or Funding InformationDr. Gavins acknowledges the support of the National Institutes of Health/National Heart, Lung, and blood Institute (NIH/NHLBI): HL125572‐01A1.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
CD8 T‐cells regulate macrophage recruitment leading to exacerbated cardiac remodeling
Authors: Pitts Cooper , Clayton Joshua , DeLeon‐Pennell Kristine Y 
Published: June 2021

Elevated CD8 T‐cell counts (>1065 cells/mm3) have been linked with increased mortality rate (2‐fold) in patients after myocardial infarction (MI). However, the exact mechanisms by which CD8 T‐cells impair cardiac wound healing post‐MI are not totally understood. We hypothesized that CD8 T‐cells regulate the inflammatory response leading to decreased survival and cardiac function post‐MI. Permanent occlusion of the left anterior descending artery was performed on C57BL/6J (WT; 4.5±0.1 months of age; n=6 males and females/day) and CD8atm1Mak mice (CD8KO; 4.1±0.2 months of age; n=6 males and females/day). CD8KO mice had improved day 7 survival (73%) compared to WT mice (50%; p<0.05). Interestingly, 100% of the CD8KO mice who died did so due to cardiac rupture of the left ventricle (LV; rupture/total deaths; 3/3) whereas 50% of WT animals (5/10; p<0.05) died of cardiac rupture. Strain analysis showed that as early as post‐MI day 3, global longitudinal strain was improved in CD8KO animals (−5.3±0.1%) compared to WT (−2.8±0.1%; p<0.05) suggesting WT mice have increased myocardial wall stress. Echocardiography measured at day 7 post‐MI showed improved cardiac physiology, as indicated by fractional shortening in CD8KO mice (11±2%) compared to WT mice (5±1%; p<0.05) implicating CD8 T‐cells as a negative regulator of wound healing during the later phase post‐MI. Proteomic plasma analysis of 111 proteins indicated CD8KO had elevated immune response at both post‐MI day 3 and day 7. This was supported by increased macrophage numbers at day 3 post‐MI in CD8KO animals compared to WT mice (p<0.05) as shown by Mac3 staining of the infarct. Collagen within the infarct was also elevated at day 3 in CD8KO compared to WT (p<0.05) as shown by picosirius red staining implicating CD8 T‐cells in regulation of myocardial fibrosis. In conclusion, CD8 T‐cells regulate macrophage recruitment and impair collagen deposition during the early phase post‐MI leading to adverse cardiac remodeling and decreased survival.Support or Funding InformationThis work was supported by the Biomedical Laboratory Research and Development Service of the Veterans Affairs Office of Research and Development Award IK2BX003922 to KYD‐P. The content is solely the responsibility of the authors and does not necessarily represent the official views of the Veterans Administration.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 Utero Exposure to Electronic Cigarettes Causes Cerebrovascular Impairment with Aging
Authors: Burrage Emily Nicole , Aboaziza Eiman A. , Marshall Kent L. , Parsley Matthew C. , Moore Josh , Johnson Abigail , O'Reilly Juliana , Hare Lance , Dangott Sydney , Tice Abigail L. , Chantler Paul D , Olfert IM 
Published: June 2021

Electronic cigarettes (Ecigs) are being promoted as safer than traditional tobacco cigarettes, leading to increased use even during pregnancy. However, the risks associated with Ecig usage during pregnancy on offspring has not been examined.Rat dams were either exposed to nicotine‐free Ecig vapor (Ecig+0) or ambient air. Rat pups were sacrificed at either one month (Air n=6, Ecig+0 n=5) or three months (Air n=4, Ecig+0 n=3). Maternal Ecig exposure (Joyetech eGrip OLED using 5‐sec puff @ 17.5 W) consisted of 30 puffs over 1‐hour each day, 5 days/week, resulting in an average daily TPM of 120mg/m3. Maternal exposure began on gestational day 2 and continued until pups were weaned. Pups themselves were never directly exposed to Ecig vapors. To examine cerebrovascular function, the middle cerebral artery (MCA) was isolated positioned in a pressurized myobath and exposed to increasing concentrations of acetylcholine (Ach; 10−9M to 10−4M), serotonin (5‐HT; 10−9M to 10−4M) and sodium nitroprusside (SNP; 10−9M to 10−4M).Significant impairment in MCA dilation to the highest dose of Ach was observed in Ecig+0 compared to air exposed pups at one month of age (13±2% vs. 30±1%, ANOVA p<0.05, respectively) as well as at three months of age (8±1% vs 23±2%, ANOVA p<0.05, respectively). The magnitude of decline in vascular reactivity for Ecig+0 exposed pups at one month and three months was different, although not statistically significant (ANOVA p<0.08). MCA constriction to 5‐HT was similar across all groups and only slight nonsignificant differences were noted in endothelial‐independent dilation in response to SNP.These data suggest offspring born to mothers who vape during pregnancy have impaired cerebrovascular function, with this impairment worsening with age, suggesting there are risks to the offspring associated with maternal Ecig use.Support or Funding InformationWVU Cancer Institute Philip R Dino Innovative Research Grant (IMO); APS STRIDE Fellowship (JO); NIHGMS 5U54GM104942‐03 (PDC)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
A Comparison of Protocols for Simulating Hemorrhage in Humans: Step vs. Ramp Lower Body Negative Pressure
Authors: Rosenberg Alexander (A.J.) , Kay Victoria L , Anderson Garen K , Sprick Justin D , Rickards Caroline A 
Published: June 2021

IntroductionLower body negative pressure (LBNP) elicits central hypovolemia, and has been used to characterize the cardiovascular and cerebrovascular responses to simulated hemorrhage in humans. LBNP protocols traditionally employ a progressive stepwise reduction in pressure that is maintained for specific time periods. More recently, however, continuous ramp LBNP protocols have been utilized to simulate the continuous nature of most bleeding injuries. The aim of this study was to compare tolerance and hemodynamic responses between a step LBNP protocol and a continuous ramp LBNP protocol until the onset of presyncope.MethodsHealthy human subjects (N=20; 8F, 12M) participated in two LBNP protocols to presyncope: 1) Step Protocol, where chamber pressure decreased every 5‐min to −15, −30, −45, −60, −70, −80, −90 and −100 mmHg, and, 2) Ramp Protocol, where chamber pressure decreased 3 mmHg/min. Heart rate (HR), mean arterial pressure (MAP), stroke volume (SV), middle and posterior cerebral artery velocity (MCAv and PCAv), muscle and cerebral oxygen saturation (SmO2 and ScO2), and endtidal CO2 (etCO2) were measured continuously. Time to presyncope, the cumulative stress index (CSI; summation of chamber pressure*time at each pressure), and hemodynamic responses were compared between the two protocols.ResultsTime to presyncope (Step: 1611.8 ± 80.5 s vs. Ramp: 1675.4 ± 68.3 s; P=0.17), and the ensuing magnitude of central hypovolemia (%Δ SV, Step: −54.3 ± 2.5 % vs. Ramp: −51.9 ± 2.7 %; P=0.31) were similar between protocols, despite a higher CSI for the step protocol (Step: 946.5 ± 98.4 mmHg*min vs. Ramp: 836.7 ± 81.6 mmHg*min; P=0.06). While there were no differences at presyncope between protocols for the maximum change in HR, MCAv, or SmO2 (P≥0.21), the reduction in MAP was slightly less (Step: −17.1 ± 1.8 % vs. Ramp: −20.0 ± 1.4 %; P=0.02) and the reductions in PCAv, ScO2, and etCO2 (P≤0.08) were slightly greater for the step protocol compared to the ramp protocol.ConclusionThese results suggest that step and continuous ramp LBNP protocols elicit relatively similar tolerance times, reductions in central blood volume, and subsequent reflex hemodynamic responses, despite a greater cumulative stress in young healthy adults.Support or Funding InformationFunding for this study was provided by the U.S. Army MRMC Combat Casualty Care Research Program Grant # W81XWH‐11‐2‐0137. The content is solely the responsibility of the authors and does not necessarily represent the official views the US Department of Defense.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Ampakine pretreatment enables a single brief hypoxic episode to evoke phrenic motor facilitation
Authors: Wollman Lila Buls , Streeter Kristi , Fuller David 
Published: June 2021

Glutamatergic synaptic transmission acting through the amino‐3‐hydro‐5‐methyl‐4‐isoxazolepropionate receptors (AMPARs) is critical for respiratory rhythmogenesis and activation of respiratory motor neurons. Ampakines are a class of synthetic pharmacological agents that act as positive allosteric modulators of AMPARs to enhance glutamatergic currents. Ampakines can be respiratory stimulants, especially during conditions of low respiratory motor output. We previously reported that pretreament with ampakine CX717 enhances long‐term facilitation of inspiratory bursting in the hypoglossal nerve following repeated hypoxic exposures in mice. Here, we used an adult rat model to test the hypothesis that ampakine pretreatment would enable a single bout of hypoxia to produce a sustained facilitation of phrenic nerve inspiratory burst amplitude. Phrenic nerve output was recorded in urethane anesthetized, mechanically ventilated and vagotomized male Sprague‐Dawley rats. Inspiratory burst amplitude and frequency, as well as heart rate and mean arterial pressure were evaluated in three experimental groups: 1) intravenous (IV) ampakine (Cx717, 15 mg/kg) (baseline PaCO2= 46.3±2.5 mmHg, n=8), 2) IV Cx717 followed 2 minutes later by a single, 5 min hypoxia challenge (baseline PaO2= 47.2±1.8 mmHg, n=8), and 3) IV vehicle (10% (2‐Hydroxypropyl)‐bcyclodextrin) + hypoxia (baseline PaO2= 46.7±5.2 mmHg, n=8). IV delivery of Cx717 produced a small, transient increase in phrenic burst amplitude and frequency which returned to baseline values by ~ 20 min. When IV ampakine was followed by hypoxia there was a sustained facilitation of phrenic inspiratory bursting that persisted to 90‐min following hypoxia (132±33 %baseline amplitude). There were no sustained changes in heart rate or blood pressure in any of the experimental groups. The sham+hypoxia treatment did not evoke phrenic facilitation, and to our knowledge, there is no evidence in the literature to suggest that a single brief bout of hypoxia can induce sustained facilitation of phrenic nerve bursting – rather the established “long term facilitation” model requires multiple bouts of hypoxia. We conclude that a low dose of ampakine Cx717 has a small and transient impact on cardiorespiratory function, but when paired with a single bout of hypoxia can induce sustained respiratory plasticity. This approach may have value in the context of hypoxia‐based neurorehabilitation strategies.Support or Funding Information1T32HL134621‐01A1 (LBW), K99 HL143207‐01 (KS), F32NS095620‐01(KS), 1R01HL139708‐01A1 (DDF)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Deficiency of the Arginase 2 Gene Protects Neonatal Mice from Hyperoxia‐Induced Lung Injury
Authors: Nelin Leif D , Jin Yi , Meng Xiaomei D , Chen Bernadette , Liu Yusen 
Published: June 2021

Bronchopulmonary dysplasia (BPD) is the most common co‐morbidity following preterm birth and is due to neonatal exposure to mechanical ventilation and/or supplemental oxygen. Neonatal mice placed in hyperoxia (85% oxygen) on post‐natal day 1 (P1) develop histological evidence of lung injury and abnormal lung development manifest by fewer and larger alveoli, otherwise termed alveolar simplification, that is reminiscent of BPD in humans. We have found in adult models of lung injury that arginase 2 induction is involved in the pathogenesis of lung injury. We tested the hypothesis that neonatal mice deficient in the Arginase 2 gene (Arg2) would have attenuated alveolar simplification. Time‐dated pregnant Arg2 deficient mice (Arg2−/−) on a C57BL/6 background and C57BL/6 (wild‐type) mice were used in these studies. Neonatal mice were placed in either room air (normoxia) or 85% oxygen (hyperoxia) by placing their cages in a Plexiglas chamber and flowing either room air or 85% oxygen through the chamber at 10 lpm. Dams were rotated daily between a normoxic litter and a hyperoxic litter to prevent oxygen toxicity in the dam. There were 4 experimental groups, wild‐type normoxia, wild‐type hyperoxia, Arg2−/− normoxia, and Arg2−/− hyperoxia. After 1, 7 or 14 days the neonatal animals were euthanized and the lungs were inflation‐fixed for H&E staining and determination of alveolar area, perimeter and number using automated software. After 1 day in hyperoxia, there were no differences between any of the four groups in terms of alveolar area (size) or alveolar number. After 7 days in hyperoxia, wild‐type mice had a substantially greater mean alveolar area than did normoxic wild‐type mice (1135±41 μm vs 465±17 μm, p<0.001). While there was no difference in normoxic wild‐type or normoxic Arg2−/− mice, hyperoxic Arg2−/− mice had significantly lower mean alveolar area (856±45 μm) than did hyperoxic wild‐type mice (p<0.001). Similar differences in alveolar perimeter were seen between the groups, i.e. hyperoxic wild‐type mice had the greatest perimeter, hyperoxic Arg2−/− were significantly lower than hyperoxic wild‐type but not as low as normoxic‐exposed animals. Furthermore, hyperoxic wild‐type mice had substantially lower mean alveolar numbers than did normoxic wild‐type mice (35±2 vs 89±3, p<0.001). There was no difference between normoxic wild‐type mice and normoxic Arg2−/− mice in mean alveolar number. Hyperoxic Arg2−/− mice had significantly more alveoli (50±2) than did hyperoxic wild‐type mice (p<0.001). These differences in alveolar area, perimeter, and number seen at 7 days remained at 14 days. Taken together these data demonstrate that deficiency of Arg2 attenuates the alveolar simplification caused by exposing neonatal mice to hyperoxia.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Transcriptional Characterization of Human Lung Cells Identifies Novel Markers for Mesenchymal Lineages
Authors: Danopoulos Soula , Bhattacharya Soumyaroop , Mariani Thomas J , Al Alam Denise 
Published: June 2021

RationaleThe lung mesenchyme gives rise to multiple distinct lineages of cells in the mature respiratory system, including smooth muscle cells (SMCs) of the airway and vasculature, vascular endothelial cells and parenchymal fibroblasts. However, a thorough understanding of the specification and inter‐relationship among mesenchymally derived cell diversity in the human lung is lacking.MethodsWe completed single cell RNA sequencing analysis of human pseudoglandular and early canalicular stage human lung cells. Canonical correlation analysis, clustering, cluster marker gene identification and tSNE representation was performed in Seurat. Cell populations were annotated using Toppfun. Immunohistochemistry (IHC) and in situ hybridization (ISH) of human lung tissues from multiple developmental stages validated spatial gene expression patterns for key marker genes.Main ResultsWe identified molecularly distinct populations representing “committed” fetal human lung endothelial cells, pericytes, and smooth muscle cells (SMCs). Early endothelial lineages expressed “classic” endothelial cell markers (PECAM, CDH5, VWF) while pericytes expressed PDGFRB, THY1 and basement membrane molecules (COL4, laminin, proteoglycans). We also observed a large population of “nonspecific” human lung mesenchymal progenitor (HLMP) cells characterized by expression of COL1, PDGFRA and multiple elastin fiber genes (ELN, MFAP4, FBLN1). We further characterized diversity of mesenchymal lineages defined by ACTA2 expression. Two mesenchymal cell populations, with the highest levels of ACTA2, expressed unique sets of markers associated with airway‐ or vascular‐associated SMCs. ISH for unique SMC cluster marker genes confirmed early and persistent spatial specification of airway (HHIP, MYLK, IGF1) and vascular (NTRK3, MEF2C) SMCs in the developing human lung.ConclusionThese data add significantly to our understanding of transcriptional phenotypes of human lung cells and provide the first ever description of molecular heterogeneity at the single cell level in human fetal lung tissue. From these data, we can identify a rich and heterogeneous set of mesenchymal cell populations, and define distinct molecular profiles for fetal human lung endothelial cells, fibroblasts, pericytes and smooth muscle cells. These data also facilitated the identification of markers for molecularly distinct populations of airway‐ and vascular smooth muscle cells, which were spatially validated across fetal development.Support or Funding InformationThis work is funded by NIH/NHLBI R01HL (to DA), and the Hastings center for pulmonary research (to SD).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.